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Merge tag 'block-5.11-2021-01-10' of git://git.kernel.dk/linux-block
[linux/fpc-iii.git] / drivers / tty / serial / amba-pl011.c
blobc255476cce287ad069f1b107a8c68547efe1dcd6
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Driver for AMBA serial ports
4 *
5 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
6 *
7 * Copyright 1999 ARM Limited
8 * Copyright (C) 2000 Deep Blue Solutions Ltd.
9 * Copyright (C) 2010 ST-Ericsson SA
10 *
11 * This is a generic driver for ARM AMBA-type serial ports. They
12 * have a lot of 16550-like features, but are not register compatible.
13 * Note that although they do have CTS, DCD and DSR inputs, they do
14 * not have an RI input, nor do they have DTR or RTS outputs. If
15 * required, these have to be supplied via some other means (eg, GPIO)
16 * and hooked into this driver.
17 */
18
19 #include <linux/module.h>
20 #include <linux/ioport.h>
21 #include <linux/init.h>
22 #include <linux/console.h>
23 #include <linux/sysrq.h>
24 #include <linux/device.h>
25 #include <linux/tty.h>
26 #include <linux/tty_flip.h>
27 #include <linux/serial_core.h>
28 #include <linux/serial.h>
29 #include <linux/amba/bus.h>
30 #include <linux/amba/serial.h>
31 #include <linux/clk.h>
32 #include <linux/slab.h>
33 #include <linux/dmaengine.h>
34 #include <linux/dma-mapping.h>
35 #include <linux/scatterlist.h>
36 #include <linux/delay.h>
37 #include <linux/types.h>
38 #include <linux/of.h>
39 #include <linux/of_device.h>
40 #include <linux/pinctrl/consumer.h>
41 #include <linux/sizes.h>
42 #include <linux/io.h>
43 #include <linux/acpi.h>
44
45 #include "amba-pl011.h"
46
47 #define UART_NR 14
48
49 #define SERIAL_AMBA_MAJOR 204
50 #define SERIAL_AMBA_MINOR 64
51 #define SERIAL_AMBA_NR UART_NR
52
53 #define AMBA_ISR_PASS_LIMIT 256
54
55 #define UART_DR_ERROR (UART011_DR_OE|UART011_DR_BE|UART011_DR_PE|UART011_DR_FE)
56 #define UART_DUMMY_DR_RX (1 << 16)
57
58 static u16 pl011_std_offsets[REG_ARRAY_SIZE] = {
59 [REG_DR] = UART01x_DR,
60 [REG_FR] = UART01x_FR,
61 [REG_LCRH_RX] = UART011_LCRH,
62 [REG_LCRH_TX] = UART011_LCRH,
63 [REG_IBRD] = UART011_IBRD,
64 [REG_FBRD] = UART011_FBRD,
65 [REG_CR] = UART011_CR,
66 [REG_IFLS] = UART011_IFLS,
67 [REG_IMSC] = UART011_IMSC,
68 [REG_RIS] = UART011_RIS,
69 [REG_MIS] = UART011_MIS,
70 [REG_ICR] = UART011_ICR,
71 [REG_DMACR] = UART011_DMACR,
72 };
73
74 /* There is by now at least one vendor with differing details, so handle it */
75 struct vendor_data {
76 const u16 *reg_offset;
77 unsigned int ifls;
78 unsigned int fr_busy;
79 unsigned int fr_dsr;
80 unsigned int fr_cts;
81 unsigned int fr_ri;
82 unsigned int inv_fr;
83 bool access_32b;
84 bool oversampling;
85 bool dma_threshold;
86 bool cts_event_workaround;
87 bool always_enabled;
88 bool fixed_options;
89
90 unsigned int (*get_fifosize)(struct amba_device *dev);
91 };
92
93 static unsigned int get_fifosize_arm(struct amba_device *dev)
94 {
95 return amba_rev(dev) < 3 ? 16 : 32;
96 }
97
98 static struct vendor_data vendor_arm = {
99 .reg_offset = pl011_std_offsets,
100 .ifls = UART011_IFLS_RX4_8|UART011_IFLS_TX4_8,
101 .fr_busy = UART01x_FR_BUSY,
102 .fr_dsr = UART01x_FR_DSR,
103 .fr_cts = UART01x_FR_CTS,
104 .fr_ri = UART011_FR_RI,
105 .oversampling = false,
106 .dma_threshold = false,
107 .cts_event_workaround = false,
108 .always_enabled = false,
109 .fixed_options = false,
110 .get_fifosize = get_fifosize_arm,
111 };
112
113 static const struct vendor_data vendor_sbsa = {
114 .reg_offset = pl011_std_offsets,
115 .fr_busy = UART01x_FR_BUSY,
116 .fr_dsr = UART01x_FR_DSR,
117 .fr_cts = UART01x_FR_CTS,
118 .fr_ri = UART011_FR_RI,
119 .access_32b = true,
120 .oversampling = false,
121 .dma_threshold = false,
122 .cts_event_workaround = false,
123 .always_enabled = true,
124 .fixed_options = true,
125 };
126
127 #ifdef CONFIG_ACPI_SPCR_TABLE
128 static const struct vendor_data vendor_qdt_qdf2400_e44 = {
129 .reg_offset = pl011_std_offsets,
130 .fr_busy = UART011_FR_TXFE,
131 .fr_dsr = UART01x_FR_DSR,
132 .fr_cts = UART01x_FR_CTS,
133 .fr_ri = UART011_FR_RI,
134 .inv_fr = UART011_FR_TXFE,
135 .access_32b = true,
136 .oversampling = false,
137 .dma_threshold = false,
138 .cts_event_workaround = false,
139 .always_enabled = true,
140 .fixed_options = true,
141 };
142 #endif
143
144 static u16 pl011_st_offsets[REG_ARRAY_SIZE] = {
145 [REG_DR] = UART01x_DR,
146 [REG_ST_DMAWM] = ST_UART011_DMAWM,
147 [REG_ST_TIMEOUT] = ST_UART011_TIMEOUT,
148 [REG_FR] = UART01x_FR,
149 [REG_LCRH_RX] = ST_UART011_LCRH_RX,
150 [REG_LCRH_TX] = ST_UART011_LCRH_TX,
151 [REG_IBRD] = UART011_IBRD,
152 [REG_FBRD] = UART011_FBRD,
153 [REG_CR] = UART011_CR,
154 [REG_IFLS] = UART011_IFLS,
155 [REG_IMSC] = UART011_IMSC,
156 [REG_RIS] = UART011_RIS,
157 [REG_MIS] = UART011_MIS,
158 [REG_ICR] = UART011_ICR,
159 [REG_DMACR] = UART011_DMACR,
160 [REG_ST_XFCR] = ST_UART011_XFCR,
161 [REG_ST_XON1] = ST_UART011_XON1,
162 [REG_ST_XON2] = ST_UART011_XON2,
163 [REG_ST_XOFF1] = ST_UART011_XOFF1,
164 [REG_ST_XOFF2] = ST_UART011_XOFF2,
165 [REG_ST_ITCR] = ST_UART011_ITCR,
166 [REG_ST_ITIP] = ST_UART011_ITIP,
167 [REG_ST_ABCR] = ST_UART011_ABCR,
168 [REG_ST_ABIMSC] = ST_UART011_ABIMSC,
169 };
170
171 static unsigned int get_fifosize_st(struct amba_device *dev)
172 {
173 return 64;
174 }
175
176 static struct vendor_data vendor_st = {
177 .reg_offset = pl011_st_offsets,
178 .ifls = UART011_IFLS_RX_HALF|UART011_IFLS_TX_HALF,
179 .fr_busy = UART01x_FR_BUSY,
180 .fr_dsr = UART01x_FR_DSR,
181 .fr_cts = UART01x_FR_CTS,
182 .fr_ri = UART011_FR_RI,
183 .oversampling = true,
184 .dma_threshold = true,
185 .cts_event_workaround = true,
186 .always_enabled = false,
187 .fixed_options = false,
188 .get_fifosize = get_fifosize_st,
189 };
190
191 static const u16 pl011_zte_offsets[REG_ARRAY_SIZE] = {
192 [REG_DR] = ZX_UART011_DR,
193 [REG_FR] = ZX_UART011_FR,
194 [REG_LCRH_RX] = ZX_UART011_LCRH,
195 [REG_LCRH_TX] = ZX_UART011_LCRH,
196 [REG_IBRD] = ZX_UART011_IBRD,
197 [REG_FBRD] = ZX_UART011_FBRD,
198 [REG_CR] = ZX_UART011_CR,
199 [REG_IFLS] = ZX_UART011_IFLS,
200 [REG_IMSC] = ZX_UART011_IMSC,
201 [REG_RIS] = ZX_UART011_RIS,
202 [REG_MIS] = ZX_UART011_MIS,
203 [REG_ICR] = ZX_UART011_ICR,
204 [REG_DMACR] = ZX_UART011_DMACR,
205 };
206
207 static unsigned int get_fifosize_zte(struct amba_device *dev)
208 {
209 return 16;
210 }
211
212 static struct vendor_data vendor_zte = {
213 .reg_offset = pl011_zte_offsets,
214 .access_32b = true,
215 .ifls = UART011_IFLS_RX4_8|UART011_IFLS_TX4_8,
216 .fr_busy = ZX_UART01x_FR_BUSY,
217 .fr_dsr = ZX_UART01x_FR_DSR,
218 .fr_cts = ZX_UART01x_FR_CTS,
219 .fr_ri = ZX_UART011_FR_RI,
220 .get_fifosize = get_fifosize_zte,
221 };
222
223 /* Deals with DMA transactions */
224
225 struct pl011_sgbuf {
226 struct scatterlist sg;
227 char *buf;
228 };
229
230 struct pl011_dmarx_data {
231 struct dma_chan *chan;
232 struct completion complete;
233 bool use_buf_b;
234 struct pl011_sgbuf sgbuf_a;
235 struct pl011_sgbuf sgbuf_b;
236 dma_cookie_t cookie;
237 bool running;
238 struct timer_list timer;
239 unsigned int last_residue;
240 unsigned long last_jiffies;
241 bool auto_poll_rate;
242 unsigned int poll_rate;
243 unsigned int poll_timeout;
244 };
245
246 struct pl011_dmatx_data {
247 struct dma_chan *chan;
248 struct scatterlist sg;
249 char *buf;
250 bool queued;
251 };
252
253 /*
254 * We wrap our port structure around the generic uart_port.
255 */
256 struct uart_amba_port {
257 struct uart_port port;
258 const u16 *reg_offset;
259 struct clk *clk;
260 const struct vendor_data *vendor;
261 unsigned int dmacr; /* dma control reg */
262 unsigned int im; /* interrupt mask */
263 unsigned int old_status;
264 unsigned int fifosize; /* vendor-specific */
265 unsigned int old_cr; /* state during shutdown */
266 unsigned int fixed_baud; /* vendor-set fixed baud rate */
267 char type[12];
268 #ifdef CONFIG_DMA_ENGINE
269 /* DMA stuff */
270 bool using_tx_dma;
271 bool using_rx_dma;
272 struct pl011_dmarx_data dmarx;
273 struct pl011_dmatx_data dmatx;
274 bool dma_probed;
275 #endif
276 };
277
278 static unsigned int pl011_reg_to_offset(const struct uart_amba_port *uap,
279 unsigned int reg)
280 {
281 return uap->reg_offset[reg];
282 }
283
284 static unsigned int pl011_read(const struct uart_amba_port *uap,
285 unsigned int reg)
286 {
287 void __iomem *addr = uap->port.membase + pl011_reg_to_offset(uap, reg);
288
289 return (uap->port.iotype == UPIO_MEM32) ?
290 readl_relaxed(addr) : readw_relaxed(addr);
291 }
292
293 static void pl011_write(unsigned int val, const struct uart_amba_port *uap,
294 unsigned int reg)
295 {
296 void __iomem *addr = uap->port.membase + pl011_reg_to_offset(uap, reg);
297
298 if (uap->port.iotype == UPIO_MEM32)
299 writel_relaxed(val, addr);
300 else
301 writew_relaxed(val, addr);
302 }
303
304 /*
305 * Reads up to 256 characters from the FIFO or until it's empty and
306 * inserts them into the TTY layer. Returns the number of characters
307 * read from the FIFO.
308 */
309 static int pl011_fifo_to_tty(struct uart_amba_port *uap)
310 {
311 unsigned int ch, flag, fifotaken;
312 int sysrq;
313 u16 status;
314
315 for (fifotaken = 0; fifotaken != 256; fifotaken++) {
316 status = pl011_read(uap, REG_FR);
317 if (status & UART01x_FR_RXFE)
318 break;
319
320 /* Take chars from the FIFO and update status */
321 ch = pl011_read(uap, REG_DR) | UART_DUMMY_DR_RX;
322 flag = TTY_NORMAL;
323 uap->port.icount.rx++;
324
325 if (unlikely(ch & UART_DR_ERROR)) {
326 if (ch & UART011_DR_BE) {
327 ch &= ~(UART011_DR_FE | UART011_DR_PE);
328 uap->port.icount.brk++;
329 if (uart_handle_break(&uap->port))
330 continue;
331 } else if (ch & UART011_DR_PE)
332 uap->port.icount.parity++;
333 else if (ch & UART011_DR_FE)
334 uap->port.icount.frame++;
335 if (ch & UART011_DR_OE)
336 uap->port.icount.overrun++;
337
338 ch &= uap->port.read_status_mask;
339
340 if (ch & UART011_DR_BE)
341 flag = TTY_BREAK;
342 else if (ch & UART011_DR_PE)
343 flag = TTY_PARITY;
344 else if (ch & UART011_DR_FE)
345 flag = TTY_FRAME;
346 }
347
348 spin_unlock(&uap->port.lock);
349 sysrq = uart_handle_sysrq_char(&uap->port, ch & 255);
350 spin_lock(&uap->port.lock);
351
352 if (!sysrq)
353 uart_insert_char(&uap->port, ch, UART011_DR_OE, ch, flag);
354 }
355
356 return fifotaken;
357 }
358
359
360 /*
361 * All the DMA operation mode stuff goes inside this ifdef.
362 * This assumes that you have a generic DMA device interface,
363 * no custom DMA interfaces are supported.
364 */
365 #ifdef CONFIG_DMA_ENGINE
366
367 #define PL011_DMA_BUFFER_SIZE PAGE_SIZE
368
369 static int pl011_sgbuf_init(struct dma_chan *chan, struct pl011_sgbuf *sg,
370 enum dma_data_direction dir)
371 {
372 dma_addr_t dma_addr;
373
374 sg->buf = dma_alloc_coherent(chan->device->dev,
375 PL011_DMA_BUFFER_SIZE, &dma_addr, GFP_KERNEL);
376 if (!sg->buf)
377 return -ENOMEM;
378
379 sg_init_table(&sg->sg, 1);
380 sg_set_page(&sg->sg, phys_to_page(dma_addr),
381 PL011_DMA_BUFFER_SIZE, offset_in_page(dma_addr));
382 sg_dma_address(&sg->sg) = dma_addr;
383 sg_dma_len(&sg->sg) = PL011_DMA_BUFFER_SIZE;
384
385 return 0;
386 }
387
388 static void pl011_sgbuf_free(struct dma_chan *chan, struct pl011_sgbuf *sg,
389 enum dma_data_direction dir)
390 {
391 if (sg->buf) {
392 dma_free_coherent(chan->device->dev,
393 PL011_DMA_BUFFER_SIZE, sg->buf,
394 sg_dma_address(&sg->sg));
395 }
396 }
397
398 static void pl011_dma_probe(struct uart_amba_port *uap)
399 {
400 /* DMA is the sole user of the platform data right now */
401 struct amba_pl011_data *plat = dev_get_platdata(uap->port.dev);
402 struct device *dev = uap->port.dev;
403 struct dma_slave_config tx_conf = {
404 .dst_addr = uap->port.mapbase +
405 pl011_reg_to_offset(uap, REG_DR),
406 .dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE,
407 .direction = DMA_MEM_TO_DEV,
408 .dst_maxburst = uap->fifosize >> 1,
409 .device_fc = false,
410 };
411 struct dma_chan *chan;
412 dma_cap_mask_t mask;
413
414 uap->dma_probed = true;
415 chan = dma_request_chan(dev, "tx");
416 if (IS_ERR(chan)) {
417 if (PTR_ERR(chan) == -EPROBE_DEFER) {
418 uap->dma_probed = false;
419 return;
420 }
421
422 /* We need platform data */
423 if (!plat || !plat->dma_filter) {
424 dev_info(uap->port.dev, "no DMA platform data\n");
425 return;
426 }
427
428 /* Try to acquire a generic DMA engine slave TX channel */
429 dma_cap_zero(mask);
430 dma_cap_set(DMA_SLAVE, mask);
431
432 chan = dma_request_channel(mask, plat->dma_filter,
433 plat->dma_tx_param);
434 if (!chan) {
435 dev_err(uap->port.dev, "no TX DMA channel!\n");
436 return;
437 }
438 }
439
440 dmaengine_slave_config(chan, &tx_conf);
441 uap->dmatx.chan = chan;
442
443 dev_info(uap->port.dev, "DMA channel TX %s\n",
444 dma_chan_name(uap->dmatx.chan));
445
446 /* Optionally make use of an RX channel as well */
447 chan = dma_request_slave_channel(dev, "rx");
448
449 if (!chan && plat && plat->dma_rx_param) {
450 chan = dma_request_channel(mask, plat->dma_filter, plat->dma_rx_param);
451
452 if (!chan) {
453 dev_err(uap->port.dev, "no RX DMA channel!\n");
454 return;
455 }
456 }
457
458 if (chan) {
459 struct dma_slave_config rx_conf = {
460 .src_addr = uap->port.mapbase +
461 pl011_reg_to_offset(uap, REG_DR),
462 .src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE,
463 .direction = DMA_DEV_TO_MEM,
464 .src_maxburst = uap->fifosize >> 2,
465 .device_fc = false,
466 };
467 struct dma_slave_caps caps;
468
469 /*
470 * Some DMA controllers provide information on their capabilities.
471 * If the controller does, check for suitable residue processing
472 * otherwise assime all is well.
473 */
474 if (0 == dma_get_slave_caps(chan, &caps)) {
475 if (caps.residue_granularity ==
476 DMA_RESIDUE_GRANULARITY_DESCRIPTOR) {
477 dma_release_channel(chan);
478 dev_info(uap->port.dev,
479 "RX DMA disabled - no residue processing\n");
480 return;
481 }
482 }
483 dmaengine_slave_config(chan, &rx_conf);
484 uap->dmarx.chan = chan;
485
486 uap->dmarx.auto_poll_rate = false;
487 if (plat && plat->dma_rx_poll_enable) {
488 /* Set poll rate if specified. */
489 if (plat->dma_rx_poll_rate) {
490 uap->dmarx.auto_poll_rate = false;
491 uap->dmarx.poll_rate = plat->dma_rx_poll_rate;
492 } else {
493 /*
494 * 100 ms defaults to poll rate if not
495 * specified. This will be adjusted with
496 * the baud rate at set_termios.
497 */
498 uap->dmarx.auto_poll_rate = true;
499 uap->dmarx.poll_rate = 100;
500 }
501 /* 3 secs defaults poll_timeout if not specified. */
502 if (plat->dma_rx_poll_timeout)
503 uap->dmarx.poll_timeout =
504 plat->dma_rx_poll_timeout;
505 else
506 uap->dmarx.poll_timeout = 3000;
507 } else if (!plat && dev->of_node) {
508 uap->dmarx.auto_poll_rate = of_property_read_bool(
509 dev->of_node, "auto-poll");
510 if (uap->dmarx.auto_poll_rate) {
511 u32 x;
512
513 if (0 == of_property_read_u32(dev->of_node,
514 "poll-rate-ms", &x))
515 uap->dmarx.poll_rate = x;
516 else
517 uap->dmarx.poll_rate = 100;
518 if (0 == of_property_read_u32(dev->of_node,
519 "poll-timeout-ms", &x))
520 uap->dmarx.poll_timeout = x;
521 else
522 uap->dmarx.poll_timeout = 3000;
523 }
524 }
525 dev_info(uap->port.dev, "DMA channel RX %s\n",
526 dma_chan_name(uap->dmarx.chan));
527 }
528 }
529
530 static void pl011_dma_remove(struct uart_amba_port *uap)
531 {
532 if (uap->dmatx.chan)
533 dma_release_channel(uap->dmatx.chan);
534 if (uap->dmarx.chan)
535 dma_release_channel(uap->dmarx.chan);
536 }
537
538 /* Forward declare these for the refill routine */
539 static int pl011_dma_tx_refill(struct uart_amba_port *uap);
540 static void pl011_start_tx_pio(struct uart_amba_port *uap);
541
542 /*
543 * The current DMA TX buffer has been sent.
544 * Try to queue up another DMA buffer.
545 */
546 static void pl011_dma_tx_callback(void *data)
547 {
548 struct uart_amba_port *uap = data;
549 struct pl011_dmatx_data *dmatx = &uap->dmatx;
550 unsigned long flags;
551 u16 dmacr;
552
553 spin_lock_irqsave(&uap->port.lock, flags);
554 if (uap->dmatx.queued)
555 dma_unmap_sg(dmatx->chan->device->dev, &dmatx->sg, 1,
556 DMA_TO_DEVICE);
557
558 dmacr = uap->dmacr;
559 uap->dmacr = dmacr & ~UART011_TXDMAE;
560 pl011_write(uap->dmacr, uap, REG_DMACR);
561
562 /*
563 * If TX DMA was disabled, it means that we've stopped the DMA for
564 * some reason (eg, XOFF received, or we want to send an X-char.)
565 *
566 * Note: we need to be careful here of a potential race between DMA
567 * and the rest of the driver - if the driver disables TX DMA while
568 * a TX buffer completing, we must update the tx queued status to
569 * get further refills (hence we check dmacr).
570 */
571 if (!(dmacr & UART011_TXDMAE) || uart_tx_stopped(&uap->port) ||
572 uart_circ_empty(&uap->port.state->xmit)) {
573 uap->dmatx.queued = false;
574 spin_unlock_irqrestore(&uap->port.lock, flags);
575 return;
576 }
577
578 if (pl011_dma_tx_refill(uap) <= 0)
579 /*
580 * We didn't queue a DMA buffer for some reason, but we
581 * have data pending to be sent. Re-enable the TX IRQ.
582 */
583 pl011_start_tx_pio(uap);
584
585 spin_unlock_irqrestore(&uap->port.lock, flags);
586 }
587
588 /*
589 * Try to refill the TX DMA buffer.
590 * Locking: called with port lock held and IRQs disabled.
591 * Returns:
592 * 1 if we queued up a TX DMA buffer.
593 * 0 if we didn't want to handle this by DMA
594 * <0 on error
595 */
596 static int pl011_dma_tx_refill(struct uart_amba_port *uap)
597 {
598 struct pl011_dmatx_data *dmatx = &uap->dmatx;
599 struct dma_chan *chan = dmatx->chan;
600 struct dma_device *dma_dev = chan->device;
601 struct dma_async_tx_descriptor *desc;
602 struct circ_buf *xmit = &uap->port.state->xmit;
603 unsigned int count;
604
605 /*
606 * Try to avoid the overhead involved in using DMA if the
607 * transaction fits in the first half of the FIFO, by using
608 * the standard interrupt handling. This ensures that we
609 * issue a uart_write_wakeup() at the appropriate time.
610 */
611 count = uart_circ_chars_pending(xmit);
612 if (count < (uap->fifosize >> 1)) {
613 uap->dmatx.queued = false;
614 return 0;
615 }
616
617 /*
618 * Bodge: don't send the last character by DMA, as this
619 * will prevent XON from notifying us to restart DMA.
620 */
621 count -= 1;
622
623 /* Else proceed to copy the TX chars to the DMA buffer and fire DMA */
624 if (count > PL011_DMA_BUFFER_SIZE)
625 count = PL011_DMA_BUFFER_SIZE;
626
627 if (xmit->tail < xmit->head)
628 memcpy(&dmatx->buf[0], &xmit->buf[xmit->tail], count);
629 else {
630 size_t first = UART_XMIT_SIZE - xmit->tail;
631 size_t second;
632
633 if (first > count)
634 first = count;
635 second = count - first;
636
637 memcpy(&dmatx->buf[0], &xmit->buf[xmit->tail], first);
638 if (second)
639 memcpy(&dmatx->buf[first], &xmit->buf[0], second);
640 }
641
642 dmatx->sg.length = count;
643
644 if (dma_map_sg(dma_dev->dev, &dmatx->sg, 1, DMA_TO_DEVICE) != 1) {
645 uap->dmatx.queued = false;
646 dev_dbg(uap->port.dev, "unable to map TX DMA\n");
647 return -EBUSY;
648 }
649
650 desc = dmaengine_prep_slave_sg(chan, &dmatx->sg, 1, DMA_MEM_TO_DEV,
651 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
652 if (!desc) {
653 dma_unmap_sg(dma_dev->dev, &dmatx->sg, 1, DMA_TO_DEVICE);
654 uap->dmatx.queued = false;
655 /*
656 * If DMA cannot be used right now, we complete this
657 * transaction via IRQ and let the TTY layer retry.
658 */
659 dev_dbg(uap->port.dev, "TX DMA busy\n");
660 return -EBUSY;
661 }
662
663 /* Some data to go along to the callback */
664 desc->callback = pl011_dma_tx_callback;
665 desc->callback_param = uap;
666
667 /* All errors should happen at prepare time */
668 dmaengine_submit(desc);
669
670 /* Fire the DMA transaction */
671 dma_dev->device_issue_pending(chan);
672
673 uap->dmacr |= UART011_TXDMAE;
674 pl011_write(uap->dmacr, uap, REG_DMACR);
675 uap->dmatx.queued = true;
676
677 /*
678 * Now we know that DMA will fire, so advance the ring buffer
679 * with the stuff we just dispatched.
680 */
681 xmit->tail = (xmit->tail + count) & (UART_XMIT_SIZE - 1);
682 uap->port.icount.tx += count;
683
684 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
685 uart_write_wakeup(&uap->port);
686
687 return 1;
688 }
689
690 /*
691 * We received a transmit interrupt without a pending X-char but with
692 * pending characters.
693 * Locking: called with port lock held and IRQs disabled.
694 * Returns:
695 * false if we want to use PIO to transmit
696 * true if we queued a DMA buffer
697 */
698 static bool pl011_dma_tx_irq(struct uart_amba_port *uap)
699 {
700 if (!uap->using_tx_dma)
701 return false;
702
703 /*
704 * If we already have a TX buffer queued, but received a
705 * TX interrupt, it will be because we've just sent an X-char.
706 * Ensure the TX DMA is enabled and the TX IRQ is disabled.
707 */
708 if (uap->dmatx.queued) {
709 uap->dmacr |= UART011_TXDMAE;
710 pl011_write(uap->dmacr, uap, REG_DMACR);
711 uap->im &= ~UART011_TXIM;
712 pl011_write(uap->im, uap, REG_IMSC);
713 return true;
714 }
715
716 /*
717 * We don't have a TX buffer queued, so try to queue one.
718 * If we successfully queued a buffer, mask the TX IRQ.
719 */
720 if (pl011_dma_tx_refill(uap) > 0) {
721 uap->im &= ~UART011_TXIM;
722 pl011_write(uap->im, uap, REG_IMSC);
723 return true;
724 }
725 return false;
726 }
727
728 /*
729 * Stop the DMA transmit (eg, due to received XOFF).
730 * Locking: called with port lock held and IRQs disabled.
731 */
732 static inline void pl011_dma_tx_stop(struct uart_amba_port *uap)
733 {
734 if (uap->dmatx.queued) {
735 uap->dmacr &= ~UART011_TXDMAE;
736 pl011_write(uap->dmacr, uap, REG_DMACR);
737 }
738 }
739
740 /*
741 * Try to start a DMA transmit, or in the case of an XON/OFF
742 * character queued for send, try to get that character out ASAP.
743 * Locking: called with port lock held and IRQs disabled.
744 * Returns:
745 * false if we want the TX IRQ to be enabled
746 * true if we have a buffer queued
747 */
748 static inline bool pl011_dma_tx_start(struct uart_amba_port *uap)
749 {
750 u16 dmacr;
751
752 if (!uap->using_tx_dma)
753 return false;
754
755 if (!uap->port.x_char) {
756 /* no X-char, try to push chars out in DMA mode */
757 bool ret = true;
758
759 if (!uap->dmatx.queued) {
760 if (pl011_dma_tx_refill(uap) > 0) {
761 uap->im &= ~UART011_TXIM;
762 pl011_write(uap->im, uap, REG_IMSC);
763 } else
764 ret = false;
765 } else if (!(uap->dmacr & UART011_TXDMAE)) {
766 uap->dmacr |= UART011_TXDMAE;
767 pl011_write(uap->dmacr, uap, REG_DMACR);
768 }
769 return ret;
770 }
771
772 /*
773 * We have an X-char to send. Disable DMA to prevent it loading
774 * the TX fifo, and then see if we can stuff it into the FIFO.
775 */
776 dmacr = uap->dmacr;
777 uap->dmacr &= ~UART011_TXDMAE;
778 pl011_write(uap->dmacr, uap, REG_DMACR);
779
780 if (pl011_read(uap, REG_FR) & UART01x_FR_TXFF) {
781 /*
782 * No space in the FIFO, so enable the transmit interrupt
783 * so we know when there is space. Note that once we've
784 * loaded the character, we should just re-enable DMA.
785 */
786 return false;
787 }
788
789 pl011_write(uap->port.x_char, uap, REG_DR);
790 uap->port.icount.tx++;
791 uap->port.x_char = 0;
792
793 /* Success - restore the DMA state */
794 uap->dmacr = dmacr;
795 pl011_write(dmacr, uap, REG_DMACR);
796
797 return true;
798 }
799
800 /*
801 * Flush the transmit buffer.
802 * Locking: called with port lock held and IRQs disabled.
803 */
804 static void pl011_dma_flush_buffer(struct uart_port *port)
805 __releases(&uap->port.lock)
806 __acquires(&uap->port.lock)
807 {
808 struct uart_amba_port *uap =
809 container_of(port, struct uart_amba_port, port);
810
811 if (!uap->using_tx_dma)
812 return;
813
814 dmaengine_terminate_async(uap->dmatx.chan);
815
816 if (uap->dmatx.queued) {
817 dma_unmap_sg(uap->dmatx.chan->device->dev, &uap->dmatx.sg, 1,
818 DMA_TO_DEVICE);
819 uap->dmatx.queued = false;
820 uap->dmacr &= ~UART011_TXDMAE;
821 pl011_write(uap->dmacr, uap, REG_DMACR);
822 }
823 }
824
825 static void pl011_dma_rx_callback(void *data);
826
827 static int pl011_dma_rx_trigger_dma(struct uart_amba_port *uap)
828 {
829 struct dma_chan *rxchan = uap->dmarx.chan;
830 struct pl011_dmarx_data *dmarx = &uap->dmarx;
831 struct dma_async_tx_descriptor *desc;
832 struct pl011_sgbuf *sgbuf;
833
834 if (!rxchan)
835 return -EIO;
836
837 /* Start the RX DMA job */
838 sgbuf = uap->dmarx.use_buf_b ?
839 &uap->dmarx.sgbuf_b : &uap->dmarx.sgbuf_a;
840 desc = dmaengine_prep_slave_sg(rxchan, &sgbuf->sg, 1,
841 DMA_DEV_TO_MEM,
842 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
843 /*
844 * If the DMA engine is busy and cannot prepare a
845 * channel, no big deal, the driver will fall back
846 * to interrupt mode as a result of this error code.
847 */
848 if (!desc) {
849 uap->dmarx.running = false;
850 dmaengine_terminate_all(rxchan);
851 return -EBUSY;
852 }
853
854 /* Some data to go along to the callback */
855 desc->callback = pl011_dma_rx_callback;
856 desc->callback_param = uap;
857 dmarx->cookie = dmaengine_submit(desc);
858 dma_async_issue_pending(rxchan);
859
860 uap->dmacr |= UART011_RXDMAE;
861 pl011_write(uap->dmacr, uap, REG_DMACR);
862 uap->dmarx.running = true;
863
864 uap->im &= ~UART011_RXIM;
865 pl011_write(uap->im, uap, REG_IMSC);
866
867 return 0;
868 }
869
870 /*
871 * This is called when either the DMA job is complete, or
872 * the FIFO timeout interrupt occurred. This must be called
873 * with the port spinlock uap->port.lock held.
874 */
875 static void pl011_dma_rx_chars(struct uart_amba_port *uap,
876 u32 pending, bool use_buf_b,
877 bool readfifo)
878 {
879 struct tty_port *port = &uap->port.state->port;
880 struct pl011_sgbuf *sgbuf = use_buf_b ?
881 &uap->dmarx.sgbuf_b : &uap->dmarx.sgbuf_a;
882 int dma_count = 0;
883 u32 fifotaken = 0; /* only used for vdbg() */
884
885 struct pl011_dmarx_data *dmarx = &uap->dmarx;
886 int dmataken = 0;
887
888 if (uap->dmarx.poll_rate) {
889 /* The data can be taken by polling */
890 dmataken = sgbuf->sg.length - dmarx->last_residue;
891 /* Recalculate the pending size */
892 if (pending >= dmataken)
893 pending -= dmataken;
894 }
895
896 /* Pick the remain data from the DMA */
897 if (pending) {
898
899 /*
900 * First take all chars in the DMA pipe, then look in the FIFO.
901 * Note that tty_insert_flip_buf() tries to take as many chars
902 * as it can.
903 */
904 dma_count = tty_insert_flip_string(port, sgbuf->buf + dmataken,
905 pending);
906
907 uap->port.icount.rx += dma_count;
908 if (dma_count < pending)
909 dev_warn(uap->port.dev,
910 "couldn't insert all characters (TTY is full?)\n");
911 }
912
913 /* Reset the last_residue for Rx DMA poll */
914 if (uap->dmarx.poll_rate)
915 dmarx->last_residue = sgbuf->sg.length;
916
917 /*
918 * Only continue with trying to read the FIFO if all DMA chars have
919 * been taken first.
920 */
921 if (dma_count == pending && readfifo) {
922 /* Clear any error flags */
923 pl011_write(UART011_OEIS | UART011_BEIS | UART011_PEIS |
924 UART011_FEIS, uap, REG_ICR);
925
926 /*
927 * If we read all the DMA'd characters, and we had an
928 * incomplete buffer, that could be due to an rx error, or
929 * maybe we just timed out. Read any pending chars and check
930 * the error status.
931 *
932 * Error conditions will only occur in the FIFO, these will
933 * trigger an immediate interrupt and stop the DMA job, so we
934 * will always find the error in the FIFO, never in the DMA
935 * buffer.
936 */
937 fifotaken = pl011_fifo_to_tty(uap);
938 }
939
940 spin_unlock(&uap->port.lock);
941 dev_vdbg(uap->port.dev,
942 "Took %d chars from DMA buffer and %d chars from the FIFO\n",
943 dma_count, fifotaken);
944 tty_flip_buffer_push(port);
945 spin_lock(&uap->port.lock);
946 }
947
948 static void pl011_dma_rx_irq(struct uart_amba_port *uap)
949 {
950 struct pl011_dmarx_data *dmarx = &uap->dmarx;
951 struct dma_chan *rxchan = dmarx->chan;
952 struct pl011_sgbuf *sgbuf = dmarx->use_buf_b ?
953 &dmarx->sgbuf_b : &dmarx->sgbuf_a;
954 size_t pending;
955 struct dma_tx_state state;
956 enum dma_status dmastat;
957
958 /*
959 * Pause the transfer so we can trust the current counter,
960 * do this before we pause the PL011 block, else we may
961 * overflow the FIFO.
962 */
963 if (dmaengine_pause(rxchan))
964 dev_err(uap->port.dev, "unable to pause DMA transfer\n");
965 dmastat = rxchan->device->device_tx_status(rxchan,
966 dmarx->cookie, &state);
967 if (dmastat != DMA_PAUSED)
968 dev_err(uap->port.dev, "unable to pause DMA transfer\n");
969
970 /* Disable RX DMA - incoming data will wait in the FIFO */
971 uap->dmacr &= ~UART011_RXDMAE;
972 pl011_write(uap->dmacr, uap, REG_DMACR);
973 uap->dmarx.running = false;
974
975 pending = sgbuf->sg.length - state.residue;
976 BUG_ON(pending > PL011_DMA_BUFFER_SIZE);
977 /* Then we terminate the transfer - we now know our residue */
978 dmaengine_terminate_all(rxchan);
979
980 /*
981 * This will take the chars we have so far and insert
982 * into the framework.
983 */
984 pl011_dma_rx_chars(uap, pending, dmarx->use_buf_b, true);
985
986 /* Switch buffer & re-trigger DMA job */
987 dmarx->use_buf_b = !dmarx->use_buf_b;
988 if (pl011_dma_rx_trigger_dma(uap)) {
989 dev_dbg(uap->port.dev, "could not retrigger RX DMA job "
990 "fall back to interrupt mode\n");
991 uap->im |= UART011_RXIM;
992 pl011_write(uap->im, uap, REG_IMSC);
993 }
994 }
995
996 static void pl011_dma_rx_callback(void *data)
997 {
998 struct uart_amba_port *uap = data;
999 struct pl011_dmarx_data *dmarx = &uap->dmarx;
1000 struct dma_chan *rxchan = dmarx->chan;
1001 bool lastbuf = dmarx->use_buf_b;
1002 struct pl011_sgbuf *sgbuf = dmarx->use_buf_b ?
1003 &dmarx->sgbuf_b : &dmarx->sgbuf_a;
1004 size_t pending;
1005 struct dma_tx_state state;
1006 int ret;
1007
1008 /*
1009 * This completion interrupt occurs typically when the
1010 * RX buffer is totally stuffed but no timeout has yet
1011 * occurred. When that happens, we just want the RX
1012 * routine to flush out the secondary DMA buffer while
1013 * we immediately trigger the next DMA job.
1014 */
1015 spin_lock_irq(&uap->port.lock);
1016 /*
1017 * Rx data can be taken by the UART interrupts during
1018 * the DMA irq handler. So we check the residue here.
1019 */
1020 rxchan->device->device_tx_status(rxchan, dmarx->cookie, &state);
1021 pending = sgbuf->sg.length - state.residue;
1022 BUG_ON(pending > PL011_DMA_BUFFER_SIZE);
1023 /* Then we terminate the transfer - we now know our residue */
1024 dmaengine_terminate_all(rxchan);
1025
1026 uap->dmarx.running = false;
1027 dmarx->use_buf_b = !lastbuf;
1028 ret = pl011_dma_rx_trigger_dma(uap);
1029
1030 pl011_dma_rx_chars(uap, pending, lastbuf, false);
1031 spin_unlock_irq(&uap->port.lock);
1032 /*
1033 * Do this check after we picked the DMA chars so we don't
1034 * get some IRQ immediately from RX.
1035 */
1036 if (ret) {
1037 dev_dbg(uap->port.dev, "could not retrigger RX DMA job "
1038 "fall back to interrupt mode\n");
1039 uap->im |= UART011_RXIM;
1040 pl011_write(uap->im, uap, REG_IMSC);
1041 }
1042 }
1043
1044 /*
1045 * Stop accepting received characters, when we're shutting down or
1046 * suspending this port.
1047 * Locking: called with port lock held and IRQs disabled.
1048 */
1049 static inline void pl011_dma_rx_stop(struct uart_amba_port *uap)
1050 {
1051 /* FIXME. Just disable the DMA enable */
1052 uap->dmacr &= ~UART011_RXDMAE;
1053 pl011_write(uap->dmacr, uap, REG_DMACR);
1054 }
1055
1056 /*
1057 * Timer handler for Rx DMA polling.
1058 * Every polling, It checks the residue in the dma buffer and transfer
1059 * data to the tty. Also, last_residue is updated for the next polling.
1060 */
1061 static void pl011_dma_rx_poll(struct timer_list *t)
1062 {
1063 struct uart_amba_port *uap = from_timer(uap, t, dmarx.timer);
1064 struct tty_port *port = &uap->port.state->port;
1065 struct pl011_dmarx_data *dmarx = &uap->dmarx;
1066 struct dma_chan *rxchan = uap->dmarx.chan;
1067 unsigned long flags = 0;
1068 unsigned int dmataken = 0;
1069 unsigned int size = 0;
1070 struct pl011_sgbuf *sgbuf;
1071 int dma_count;
1072 struct dma_tx_state state;
1073
1074 sgbuf = dmarx->use_buf_b ? &uap->dmarx.sgbuf_b : &uap->dmarx.sgbuf_a;
1075 rxchan->device->device_tx_status(rxchan, dmarx->cookie, &state);
1076 if (likely(state.residue < dmarx->last_residue)) {
1077 dmataken = sgbuf->sg.length - dmarx->last_residue;
1078 size = dmarx->last_residue - state.residue;
1079 dma_count = tty_insert_flip_string(port, sgbuf->buf + dmataken,
1080 size);
1081 if (dma_count == size)
1082 dmarx->last_residue = state.residue;
1083 dmarx->last_jiffies = jiffies;
1084 }
1085 tty_flip_buffer_push(port);
1086
1087 /*
1088 * If no data is received in poll_timeout, the driver will fall back
1089 * to interrupt mode. We will retrigger DMA at the first interrupt.
1090 */
1091 if (jiffies_to_msecs(jiffies - dmarx->last_jiffies)
1092 > uap->dmarx.poll_timeout) {
1093
1094 spin_lock_irqsave(&uap->port.lock, flags);
1095 pl011_dma_rx_stop(uap);
1096 uap->im |= UART011_RXIM;
1097 pl011_write(uap->im, uap, REG_IMSC);
1098 spin_unlock_irqrestore(&uap->port.lock, flags);
1099
1100 uap->dmarx.running = false;
1101 dmaengine_terminate_all(rxchan);
1102 del_timer(&uap->dmarx.timer);
1103 } else {
1104 mod_timer(&uap->dmarx.timer,
1105 jiffies + msecs_to_jiffies(uap->dmarx.poll_rate));
1106 }
1107 }
1108
1109 static void pl011_dma_startup(struct uart_amba_port *uap)
1110 {
1111 int ret;
1112
1113 if (!uap->dma_probed)
1114 pl011_dma_probe(uap);
1115
1116 if (!uap->dmatx.chan)
1117 return;
1118
1119 uap->dmatx.buf = kmalloc(PL011_DMA_BUFFER_SIZE, GFP_KERNEL | __GFP_DMA);
1120 if (!uap->dmatx.buf) {
1121 dev_err(uap->port.dev, "no memory for DMA TX buffer\n");
1122 uap->port.fifosize = uap->fifosize;
1123 return;
1124 }
1125
1126 sg_init_one(&uap->dmatx.sg, uap->dmatx.buf, PL011_DMA_BUFFER_SIZE);
1127
1128 /* The DMA buffer is now the FIFO the TTY subsystem can use */
1129 uap->port.fifosize = PL011_DMA_BUFFER_SIZE;
1130 uap->using_tx_dma = true;
1131
1132 if (!uap->dmarx.chan)
1133 goto skip_rx;
1134
1135 /* Allocate and map DMA RX buffers */
1136 ret = pl011_sgbuf_init(uap->dmarx.chan, &uap->dmarx.sgbuf_a,
1137 DMA_FROM_DEVICE);
1138 if (ret) {
1139 dev_err(uap->port.dev, "failed to init DMA %s: %d\n",
1140 "RX buffer A", ret);
1141 goto skip_rx;
1142 }
1143
1144 ret = pl011_sgbuf_init(uap->dmarx.chan, &uap->dmarx.sgbuf_b,
1145 DMA_FROM_DEVICE);
1146 if (ret) {
1147 dev_err(uap->port.dev, "failed to init DMA %s: %d\n",
1148 "RX buffer B", ret);
1149 pl011_sgbuf_free(uap->dmarx.chan, &uap->dmarx.sgbuf_a,
1150 DMA_FROM_DEVICE);
1151 goto skip_rx;
1152 }
1153
1154 uap->using_rx_dma = true;
1155
1156 skip_rx:
1157 /* Turn on DMA error (RX/TX will be enabled on demand) */
1158 uap->dmacr |= UART011_DMAONERR;
1159 pl011_write(uap->dmacr, uap, REG_DMACR);
1160
1161 /*
1162 * ST Micro variants has some specific dma burst threshold
1163 * compensation. Set this to 16 bytes, so burst will only
1164 * be issued above/below 16 bytes.
1165 */
1166 if (uap->vendor->dma_threshold)
1167 pl011_write(ST_UART011_DMAWM_RX_16 | ST_UART011_DMAWM_TX_16,
1168 uap, REG_ST_DMAWM);
1169
1170 if (uap->using_rx_dma) {
1171 if (pl011_dma_rx_trigger_dma(uap))
1172 dev_dbg(uap->port.dev, "could not trigger initial "
1173 "RX DMA job, fall back to interrupt mode\n");
1174 if (uap->dmarx.poll_rate) {
1175 timer_setup(&uap->dmarx.timer, pl011_dma_rx_poll, 0);
1176 mod_timer(&uap->dmarx.timer,
1177 jiffies +
1178 msecs_to_jiffies(uap->dmarx.poll_rate));
1179 uap->dmarx.last_residue = PL011_DMA_BUFFER_SIZE;
1180 uap->dmarx.last_jiffies = jiffies;
1181 }
1182 }
1183 }
1184
1185 static void pl011_dma_shutdown(struct uart_amba_port *uap)
1186 {
1187 if (!(uap->using_tx_dma || uap->using_rx_dma))
1188 return;
1189
1190 /* Disable RX and TX DMA */
1191 while (pl011_read(uap, REG_FR) & uap->vendor->fr_busy)
1192 cpu_relax();
1193
1194 spin_lock_irq(&uap->port.lock);
1195 uap->dmacr &= ~(UART011_DMAONERR | UART011_RXDMAE | UART011_TXDMAE);
1196 pl011_write(uap->dmacr, uap, REG_DMACR);
1197 spin_unlock_irq(&uap->port.lock);
1198
1199 if (uap->using_tx_dma) {
1200 /* In theory, this should already be done by pl011_dma_flush_buffer */
1201 dmaengine_terminate_all(uap->dmatx.chan);
1202 if (uap->dmatx.queued) {
1203 dma_unmap_sg(uap->dmatx.chan->device->dev, &uap->dmatx.sg, 1,
1204 DMA_TO_DEVICE);
1205 uap->dmatx.queued = false;
1206 }
1207
1208 kfree(uap->dmatx.buf);
1209 uap->using_tx_dma = false;
1210 }
1211
1212 if (uap->using_rx_dma) {
1213 dmaengine_terminate_all(uap->dmarx.chan);
1214 /* Clean up the RX DMA */
1215 pl011_sgbuf_free(uap->dmarx.chan, &uap->dmarx.sgbuf_a, DMA_FROM_DEVICE);
1216 pl011_sgbuf_free(uap->dmarx.chan, &uap->dmarx.sgbuf_b, DMA_FROM_DEVICE);
1217 if (uap->dmarx.poll_rate)
1218 del_timer_sync(&uap->dmarx.timer);
1219 uap->using_rx_dma = false;
1220 }
1221 }
1222
1223 static inline bool pl011_dma_rx_available(struct uart_amba_port *uap)
1224 {
1225 return uap->using_rx_dma;
1226 }
1227
1228 static inline bool pl011_dma_rx_running(struct uart_amba_port *uap)
1229 {
1230 return uap->using_rx_dma && uap->dmarx.running;
1231 }
1232
1233 #else
1234 /* Blank functions if the DMA engine is not available */
1235 static inline void pl011_dma_remove(struct uart_amba_port *uap)
1236 {
1237 }
1238
1239 static inline void pl011_dma_startup(struct uart_amba_port *uap)
1240 {
1241 }
1242
1243 static inline void pl011_dma_shutdown(struct uart_amba_port *uap)
1244 {
1245 }
1246
1247 static inline bool pl011_dma_tx_irq(struct uart_amba_port *uap)
1248 {
1249 return false;
1250 }
1251
1252 static inline void pl011_dma_tx_stop(struct uart_amba_port *uap)
1253 {
1254 }
1255
1256 static inline bool pl011_dma_tx_start(struct uart_amba_port *uap)
1257 {
1258 return false;
1259 }
1260
1261 static inline void pl011_dma_rx_irq(struct uart_amba_port *uap)
1262 {
1263 }
1264
1265 static inline void pl011_dma_rx_stop(struct uart_amba_port *uap)
1266 {
1267 }
1268
1269 static inline int pl011_dma_rx_trigger_dma(struct uart_amba_port *uap)
1270 {
1271 return -EIO;
1272 }
1273
1274 static inline bool pl011_dma_rx_available(struct uart_amba_port *uap)
1275 {
1276 return false;
1277 }
1278
1279 static inline bool pl011_dma_rx_running(struct uart_amba_port *uap)
1280 {
1281 return false;
1282 }
1283
1284 #define pl011_dma_flush_buffer NULL
1285 #endif
1286
1287 static void pl011_stop_tx(struct uart_port *port)
1288 {
1289 struct uart_amba_port *uap =
1290 container_of(port, struct uart_amba_port, port);
1291
1292 uap->im &= ~UART011_TXIM;
1293 pl011_write(uap->im, uap, REG_IMSC);
1294 pl011_dma_tx_stop(uap);
1295 }
1296
1297 static bool pl011_tx_chars(struct uart_amba_port *uap, bool from_irq);
1298
1299 /* Start TX with programmed I/O only (no DMA) */
1300 static void pl011_start_tx_pio(struct uart_amba_port *uap)
1301 {
1302 if (pl011_tx_chars(uap, false)) {
1303 uap->im |= UART011_TXIM;
1304 pl011_write(uap->im, uap, REG_IMSC);
1305 }
1306 }
1307
1308 static void pl011_start_tx(struct uart_port *port)
1309 {
1310 struct uart_amba_port *uap =
1311 container_of(port, struct uart_amba_port, port);
1312
1313 if (!pl011_dma_tx_start(uap))
1314 pl011_start_tx_pio(uap);
1315 }
1316
1317 static void pl011_stop_rx(struct uart_port *port)
1318 {
1319 struct uart_amba_port *uap =
1320 container_of(port, struct uart_amba_port, port);
1321
1322 uap->im &= ~(UART011_RXIM|UART011_RTIM|UART011_FEIM|
1323 UART011_PEIM|UART011_BEIM|UART011_OEIM);
1324 pl011_write(uap->im, uap, REG_IMSC);
1325
1326 pl011_dma_rx_stop(uap);
1327 }
1328
1329 static void pl011_enable_ms(struct uart_port *port)
1330 {
1331 struct uart_amba_port *uap =
1332 container_of(port, struct uart_amba_port, port);
1333
1334 uap->im |= UART011_RIMIM|UART011_CTSMIM|UART011_DCDMIM|UART011_DSRMIM;
1335 pl011_write(uap->im, uap, REG_IMSC);
1336 }
1337
1338 static void pl011_rx_chars(struct uart_amba_port *uap)
1339 __releases(&uap->port.lock)
1340 __acquires(&uap->port.lock)
1341 {
1342 pl011_fifo_to_tty(uap);
1343
1344 spin_unlock(&uap->port.lock);
1345 tty_flip_buffer_push(&uap->port.state->port);
1346 /*
1347 * If we were temporarily out of DMA mode for a while,
1348 * attempt to switch back to DMA mode again.
1349 */
1350 if (pl011_dma_rx_available(uap)) {
1351 if (pl011_dma_rx_trigger_dma(uap)) {
1352 dev_dbg(uap->port.dev, "could not trigger RX DMA job "
1353 "fall back to interrupt mode again\n");
1354 uap->im |= UART011_RXIM;
1355 pl011_write(uap->im, uap, REG_IMSC);
1356 } else {
1357 #ifdef CONFIG_DMA_ENGINE
1358 /* Start Rx DMA poll */
1359 if (uap->dmarx.poll_rate) {
1360 uap->dmarx.last_jiffies = jiffies;
1361 uap->dmarx.last_residue = PL011_DMA_BUFFER_SIZE;
1362 mod_timer(&uap->dmarx.timer,
1363 jiffies +
1364 msecs_to_jiffies(uap->dmarx.poll_rate));
1365 }
1366 #endif
1367 }
1368 }
1369 spin_lock(&uap->port.lock);
1370 }
1371
1372 static bool pl011_tx_char(struct uart_amba_port *uap, unsigned char c,
1373 bool from_irq)
1374 {
1375 if (unlikely(!from_irq) &&
1376 pl011_read(uap, REG_FR) & UART01x_FR_TXFF)
1377 return false; /* unable to transmit character */
1378
1379 pl011_write(c, uap, REG_DR);
1380 uap->port.icount.tx++;
1381
1382 return true;
1383 }
1384
1385 /* Returns true if tx interrupts have to be (kept) enabled */
1386 static bool pl011_tx_chars(struct uart_amba_port *uap, bool from_irq)
1387 {
1388 struct circ_buf *xmit = &uap->port.state->xmit;
1389 int count = uap->fifosize >> 1;
1390
1391 if (uap->port.x_char) {
1392 if (!pl011_tx_char(uap, uap->port.x_char, from_irq))
1393 return true;
1394 uap->port.x_char = 0;
1395 --count;
1396 }
1397 if (uart_circ_empty(xmit) || uart_tx_stopped(&uap->port)) {
1398 pl011_stop_tx(&uap->port);
1399 return false;
1400 }
1401
1402 /* If we are using DMA mode, try to send some characters. */
1403 if (pl011_dma_tx_irq(uap))
1404 return true;
1405
1406 do {
1407 if (likely(from_irq) && count-- == 0)
1408 break;
1409
1410 if (!pl011_tx_char(uap, xmit->buf[xmit->tail], from_irq))
1411 break;
1412
1413 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
1414 } while (!uart_circ_empty(xmit));
1415
1416 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
1417 uart_write_wakeup(&uap->port);
1418
1419 if (uart_circ_empty(xmit)) {
1420 pl011_stop_tx(&uap->port);
1421 return false;
1422 }
1423 return true;
1424 }
1425
1426 static void pl011_modem_status(struct uart_amba_port *uap)
1427 {
1428 unsigned int status, delta;
1429
1430 status = pl011_read(uap, REG_FR) & UART01x_FR_MODEM_ANY;
1431
1432 delta = status ^ uap->old_status;
1433 uap->old_status = status;
1434
1435 if (!delta)
1436 return;
1437
1438 if (delta & UART01x_FR_DCD)
1439 uart_handle_dcd_change(&uap->port, status & UART01x_FR_DCD);
1440
1441 if (delta & uap->vendor->fr_dsr)
1442 uap->port.icount.dsr++;
1443
1444 if (delta & uap->vendor->fr_cts)
1445 uart_handle_cts_change(&uap->port,
1446 status & uap->vendor->fr_cts);
1447
1448 wake_up_interruptible(&uap->port.state->port.delta_msr_wait);
1449 }
1450
1451 static void check_apply_cts_event_workaround(struct uart_amba_port *uap)
1452 {
1453 if (!uap->vendor->cts_event_workaround)
1454 return;
1455
1456 /* workaround to make sure that all bits are unlocked.. */
1457 pl011_write(0x00, uap, REG_ICR);
1458
1459 /*
1460 * WA: introduce 26ns(1 uart clk) delay before W1C;
1461 * single apb access will incur 2 pclk(133.12Mhz) delay,
1462 * so add 2 dummy reads
1463 */
1464 pl011_read(uap, REG_ICR);
1465 pl011_read(uap, REG_ICR);
1466 }
1467
1468 static irqreturn_t pl011_int(int irq, void *dev_id)
1469 {
1470 struct uart_amba_port *uap = dev_id;
1471 unsigned long flags;
1472 unsigned int status, pass_counter = AMBA_ISR_PASS_LIMIT;
1473 int handled = 0;
1474
1475 spin_lock_irqsave(&uap->port.lock, flags);
1476 status = pl011_read(uap, REG_RIS) & uap->im;
1477 if (status) {
1478 do {
1479 check_apply_cts_event_workaround(uap);
1480
1481 pl011_write(status & ~(UART011_TXIS|UART011_RTIS|
1482 UART011_RXIS),
1483 uap, REG_ICR);
1484
1485 if (status & (UART011_RTIS|UART011_RXIS)) {
1486 if (pl011_dma_rx_running(uap))
1487 pl011_dma_rx_irq(uap);
1488 else
1489 pl011_rx_chars(uap);
1490 }
1491 if (status & (UART011_DSRMIS|UART011_DCDMIS|
1492 UART011_CTSMIS|UART011_RIMIS))
1493 pl011_modem_status(uap);
1494 if (status & UART011_TXIS)
1495 pl011_tx_chars(uap, true);
1496
1497 if (pass_counter-- == 0)
1498 break;
1499
1500 status = pl011_read(uap, REG_RIS) & uap->im;
1501 } while (status != 0);
1502 handled = 1;
1503 }
1504
1505 spin_unlock_irqrestore(&uap->port.lock, flags);
1506
1507 return IRQ_RETVAL(handled);
1508 }
1509
1510 static unsigned int pl011_tx_empty(struct uart_port *port)
1511 {
1512 struct uart_amba_port *uap =
1513 container_of(port, struct uart_amba_port, port);
1514
1515 /* Allow feature register bits to be inverted to work around errata */
1516 unsigned int status = pl011_read(uap, REG_FR) ^ uap->vendor->inv_fr;
1517
1518 return status & (uap->vendor->fr_busy | UART01x_FR_TXFF) ?
1519 0 : TIOCSER_TEMT;
1520 }
1521
1522 static unsigned int pl011_get_mctrl(struct uart_port *port)
1523 {
1524 struct uart_amba_port *uap =
1525 container_of(port, struct uart_amba_port, port);
1526 unsigned int result = 0;
1527 unsigned int status = pl011_read(uap, REG_FR);
1528
1529 #define TIOCMBIT(uartbit, tiocmbit) \
1530 if (status & uartbit) \
1531 result |= tiocmbit
1532
1533 TIOCMBIT(UART01x_FR_DCD, TIOCM_CAR);
1534 TIOCMBIT(uap->vendor->fr_dsr, TIOCM_DSR);
1535 TIOCMBIT(uap->vendor->fr_cts, TIOCM_CTS);
1536 TIOCMBIT(uap->vendor->fr_ri, TIOCM_RNG);
1537 #undef TIOCMBIT
1538 return result;
1539 }
1540
1541 static void pl011_set_mctrl(struct uart_port *port, unsigned int mctrl)
1542 {
1543 struct uart_amba_port *uap =
1544 container_of(port, struct uart_amba_port, port);
1545 unsigned int cr;
1546
1547 cr = pl011_read(uap, REG_CR);
1548
1549 #define TIOCMBIT(tiocmbit, uartbit) \
1550 if (mctrl & tiocmbit) \
1551 cr |= uartbit; \
1552 else \
1553 cr &= ~uartbit
1554
1555 TIOCMBIT(TIOCM_RTS, UART011_CR_RTS);
1556 TIOCMBIT(TIOCM_DTR, UART011_CR_DTR);
1557 TIOCMBIT(TIOCM_OUT1, UART011_CR_OUT1);
1558 TIOCMBIT(TIOCM_OUT2, UART011_CR_OUT2);
1559 TIOCMBIT(TIOCM_LOOP, UART011_CR_LBE);
1560
1561 if (port->status & UPSTAT_AUTORTS) {
1562 /* We need to disable auto-RTS if we want to turn RTS off */
1563 TIOCMBIT(TIOCM_RTS, UART011_CR_RTSEN);
1564 }
1565 #undef TIOCMBIT
1566
1567 pl011_write(cr, uap, REG_CR);
1568 }
1569
1570 static void pl011_break_ctl(struct uart_port *port, int break_state)
1571 {
1572 struct uart_amba_port *uap =
1573 container_of(port, struct uart_amba_port, port);
1574 unsigned long flags;
1575 unsigned int lcr_h;
1576
1577 spin_lock_irqsave(&uap->port.lock, flags);
1578 lcr_h = pl011_read(uap, REG_LCRH_TX);
1579 if (break_state == -1)
1580 lcr_h |= UART01x_LCRH_BRK;
1581 else
1582 lcr_h &= ~UART01x_LCRH_BRK;
1583 pl011_write(lcr_h, uap, REG_LCRH_TX);
1584 spin_unlock_irqrestore(&uap->port.lock, flags);
1585 }
1586
1587 #ifdef CONFIG_CONSOLE_POLL
1588
1589 static void pl011_quiesce_irqs(struct uart_port *port)
1590 {
1591 struct uart_amba_port *uap =
1592 container_of(port, struct uart_amba_port, port);
1593
1594 pl011_write(pl011_read(uap, REG_MIS), uap, REG_ICR);
1595 /*
1596 * There is no way to clear TXIM as this is "ready to transmit IRQ", so
1597 * we simply mask it. start_tx() will unmask it.
1598 *
1599 * Note we can race with start_tx(), and if the race happens, the
1600 * polling user might get another interrupt just after we clear it.
1601 * But it should be OK and can happen even w/o the race, e.g.
1602 * controller immediately got some new data and raised the IRQ.
1603 *
1604 * And whoever uses polling routines assumes that it manages the device
1605 * (including tx queue), so we're also fine with start_tx()'s caller
1606 * side.
1607 */
1608 pl011_write(pl011_read(uap, REG_IMSC) & ~UART011_TXIM, uap,
1609 REG_IMSC);
1610 }
1611
1612 static int pl011_get_poll_char(struct uart_port *port)
1613 {
1614 struct uart_amba_port *uap =
1615 container_of(port, struct uart_amba_port, port);
1616 unsigned int status;
1617
1618 /*
1619 * The caller might need IRQs lowered, e.g. if used with KDB NMI
1620 * debugger.
1621 */
1622 pl011_quiesce_irqs(port);
1623
1624 status = pl011_read(uap, REG_FR);
1625 if (status & UART01x_FR_RXFE)
1626 return NO_POLL_CHAR;
1627
1628 return pl011_read(uap, REG_DR);
1629 }
1630
1631 static void pl011_put_poll_char(struct uart_port *port,
1632 unsigned char ch)
1633 {
1634 struct uart_amba_port *uap =
1635 container_of(port, struct uart_amba_port, port);
1636
1637 while (pl011_read(uap, REG_FR) & UART01x_FR_TXFF)
1638 cpu_relax();
1639
1640 pl011_write(ch, uap, REG_DR);
1641 }
1642
1643 #endif /* CONFIG_CONSOLE_POLL */
1644
1645 static int pl011_hwinit(struct uart_port *port)
1646 {
1647 struct uart_amba_port *uap =
1648 container_of(port, struct uart_amba_port, port);
1649 int retval;
1650
1651 /* Optionaly enable pins to be muxed in and configured */
1652 pinctrl_pm_select_default_state(port->dev);
1653
1654 /*
1655 * Try to enable the clock producer.
1656 */
1657 retval = clk_prepare_enable(uap->clk);
1658 if (retval)
1659 return retval;
1660
1661 uap->port.uartclk = clk_get_rate(uap->clk);
1662
1663 /* Clear pending error and receive interrupts */
1664 pl011_write(UART011_OEIS | UART011_BEIS | UART011_PEIS |
1665 UART011_FEIS | UART011_RTIS | UART011_RXIS,
1666 uap, REG_ICR);
1667
1668 /*
1669 * Save interrupts enable mask, and enable RX interrupts in case if
1670 * the interrupt is used for NMI entry.
1671 */
1672 uap->im = pl011_read(uap, REG_IMSC);
1673 pl011_write(UART011_RTIM | UART011_RXIM, uap, REG_IMSC);
1674
1675 if (dev_get_platdata(uap->port.dev)) {
1676 struct amba_pl011_data *plat;
1677
1678 plat = dev_get_platdata(uap->port.dev);
1679 if (plat->init)
1680 plat->init();
1681 }
1682 return 0;
1683 }
1684
1685 static bool pl011_split_lcrh(const struct uart_amba_port *uap)
1686 {
1687 return pl011_reg_to_offset(uap, REG_LCRH_RX) !=
1688 pl011_reg_to_offset(uap, REG_LCRH_TX);
1689 }
1690
1691 static void pl011_write_lcr_h(struct uart_amba_port *uap, unsigned int lcr_h)
1692 {
1693 pl011_write(lcr_h, uap, REG_LCRH_RX);
1694 if (pl011_split_lcrh(uap)) {
1695 int i;
1696 /*
1697 * Wait 10 PCLKs before writing LCRH_TX register,
1698 * to get this delay write read only register 10 times
1699 */
1700 for (i = 0; i < 10; ++i)
1701 pl011_write(0xff, uap, REG_MIS);
1702 pl011_write(lcr_h, uap, REG_LCRH_TX);
1703 }
1704 }
1705
1706 static int pl011_allocate_irq(struct uart_amba_port *uap)
1707 {
1708 pl011_write(uap->im, uap, REG_IMSC);
1709
1710 return request_irq(uap->port.irq, pl011_int, IRQF_SHARED, "uart-pl011", uap);
1711 }
1712
1713 /*
1714 * Enable interrupts, only timeouts when using DMA
1715 * if initial RX DMA job failed, start in interrupt mode
1716 * as well.
1717 */
1718 static void pl011_enable_interrupts(struct uart_amba_port *uap)
1719 {
1720 unsigned int i;
1721
1722 spin_lock_irq(&uap->port.lock);
1723
1724 /* Clear out any spuriously appearing RX interrupts */
1725 pl011_write(UART011_RTIS | UART011_RXIS, uap, REG_ICR);
1726
1727 /*
1728 * RXIS is asserted only when the RX FIFO transitions from below
1729 * to above the trigger threshold. If the RX FIFO is already
1730 * full to the threshold this can't happen and RXIS will now be
1731 * stuck off. Drain the RX FIFO explicitly to fix this:
1732 */
1733 for (i = 0; i < uap->fifosize * 2; ++i) {
1734 if (pl011_read(uap, REG_FR) & UART01x_FR_RXFE)
1735 break;
1736
1737 pl011_read(uap, REG_DR);
1738 }
1739
1740 uap->im = UART011_RTIM;
1741 if (!pl011_dma_rx_running(uap))
1742 uap->im |= UART011_RXIM;
1743 pl011_write(uap->im, uap, REG_IMSC);
1744 spin_unlock_irq(&uap->port.lock);
1745 }
1746
1747 static int pl011_startup(struct uart_port *port)
1748 {
1749 struct uart_amba_port *uap =
1750 container_of(port, struct uart_amba_port, port);
1751 unsigned int cr;
1752 int retval;
1753
1754 retval = pl011_hwinit(port);
1755 if (retval)
1756 goto clk_dis;
1757
1758 retval = pl011_allocate_irq(uap);
1759 if (retval)
1760 goto clk_dis;
1761
1762 pl011_write(uap->vendor->ifls, uap, REG_IFLS);
1763
1764 spin_lock_irq(&uap->port.lock);
1765
1766 /* restore RTS and DTR */
1767 cr = uap->old_cr & (UART011_CR_RTS | UART011_CR_DTR);
1768 cr |= UART01x_CR_UARTEN | UART011_CR_RXE | UART011_CR_TXE;
1769 pl011_write(cr, uap, REG_CR);
1770
1771 spin_unlock_irq(&uap->port.lock);
1772
1773 /*
1774 * initialise the old status of the modem signals
1775 */
1776 uap->old_status = pl011_read(uap, REG_FR) & UART01x_FR_MODEM_ANY;
1777
1778 /* Startup DMA */
1779 pl011_dma_startup(uap);
1780
1781 pl011_enable_interrupts(uap);
1782
1783 return 0;
1784
1785 clk_dis:
1786 clk_disable_unprepare(uap->clk);
1787 return retval;
1788 }
1789
1790 static int sbsa_uart_startup(struct uart_port *port)
1791 {
1792 struct uart_amba_port *uap =
1793 container_of(port, struct uart_amba_port, port);
1794 int retval;
1795
1796 retval = pl011_hwinit(port);
1797 if (retval)
1798 return retval;
1799
1800 retval = pl011_allocate_irq(uap);
1801 if (retval)
1802 return retval;
1803
1804 /* The SBSA UART does not support any modem status lines. */
1805 uap->old_status = 0;
1806
1807 pl011_enable_interrupts(uap);
1808
1809 return 0;
1810 }
1811
1812 static void pl011_shutdown_channel(struct uart_amba_port *uap,
1813 unsigned int lcrh)
1814 {
1815 unsigned long val;
1816
1817 val = pl011_read(uap, lcrh);
1818 val &= ~(UART01x_LCRH_BRK | UART01x_LCRH_FEN);
1819 pl011_write(val, uap, lcrh);
1820 }
1821
1822 /*
1823 * disable the port. It should not disable RTS and DTR.
1824 * Also RTS and DTR state should be preserved to restore
1825 * it during startup().
1826 */
1827 static void pl011_disable_uart(struct uart_amba_port *uap)
1828 {
1829 unsigned int cr;
1830
1831 uap->port.status &= ~(UPSTAT_AUTOCTS | UPSTAT_AUTORTS);
1832 spin_lock_irq(&uap->port.lock);
1833 cr = pl011_read(uap, REG_CR);
1834 uap->old_cr = cr;
1835 cr &= UART011_CR_RTS | UART011_CR_DTR;
1836 cr |= UART01x_CR_UARTEN | UART011_CR_TXE;
1837 pl011_write(cr, uap, REG_CR);
1838 spin_unlock_irq(&uap->port.lock);
1839
1840 /*
1841 * disable break condition and fifos
1842 */
1843 pl011_shutdown_channel(uap, REG_LCRH_RX);
1844 if (pl011_split_lcrh(uap))
1845 pl011_shutdown_channel(uap, REG_LCRH_TX);
1846 }
1847
1848 static void pl011_disable_interrupts(struct uart_amba_port *uap)
1849 {
1850 spin_lock_irq(&uap->port.lock);
1851
1852 /* mask all interrupts and clear all pending ones */
1853 uap->im = 0;
1854 pl011_write(uap->im, uap, REG_IMSC);
1855 pl011_write(0xffff, uap, REG_ICR);
1856
1857 spin_unlock_irq(&uap->port.lock);
1858 }
1859
1860 static void pl011_shutdown(struct uart_port *port)
1861 {
1862 struct uart_amba_port *uap =
1863 container_of(port, struct uart_amba_port, port);
1864
1865 pl011_disable_interrupts(uap);
1866
1867 pl011_dma_shutdown(uap);
1868
1869 free_irq(uap->port.irq, uap);
1870
1871 pl011_disable_uart(uap);
1872
1873 /*
1874 * Shut down the clock producer
1875 */
1876 clk_disable_unprepare(uap->clk);
1877 /* Optionally let pins go into sleep states */
1878 pinctrl_pm_select_sleep_state(port->dev);
1879
1880 if (dev_get_platdata(uap->port.dev)) {
1881 struct amba_pl011_data *plat;
1882
1883 plat = dev_get_platdata(uap->port.dev);
1884 if (plat->exit)
1885 plat->exit();
1886 }
1887
1888 if (uap->port.ops->flush_buffer)
1889 uap->port.ops->flush_buffer(port);
1890 }
1891
1892 static void sbsa_uart_shutdown(struct uart_port *port)
1893 {
1894 struct uart_amba_port *uap =
1895 container_of(port, struct uart_amba_port, port);
1896
1897 pl011_disable_interrupts(uap);
1898
1899 free_irq(uap->port.irq, uap);
1900
1901 if (uap->port.ops->flush_buffer)
1902 uap->port.ops->flush_buffer(port);
1903 }
1904
1905 static void
1906 pl011_setup_status_masks(struct uart_port *port, struct ktermios *termios)
1907 {
1908 port->read_status_mask = UART011_DR_OE | 255;
1909 if (termios->c_iflag & INPCK)
1910 port->read_status_mask |= UART011_DR_FE | UART011_DR_PE;
1911 if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
1912 port->read_status_mask |= UART011_DR_BE;
1913
1914 /*
1915 * Characters to ignore
1916 */
1917 port->ignore_status_mask = 0;
1918 if (termios->c_iflag & IGNPAR)
1919 port->ignore_status_mask |= UART011_DR_FE | UART011_DR_PE;
1920 if (termios->c_iflag & IGNBRK) {
1921 port->ignore_status_mask |= UART011_DR_BE;
1922 /*
1923 * If we're ignoring parity and break indicators,
1924 * ignore overruns too (for real raw support).
1925 */
1926 if (termios->c_iflag & IGNPAR)
1927 port->ignore_status_mask |= UART011_DR_OE;
1928 }
1929
1930 /*
1931 * Ignore all characters if CREAD is not set.
1932 */
1933 if ((termios->c_cflag & CREAD) == 0)
1934 port->ignore_status_mask |= UART_DUMMY_DR_RX;
1935 }
1936
1937 static void
1938 pl011_set_termios(struct uart_port *port, struct ktermios *termios,
1939 struct ktermios *old)
1940 {
1941 struct uart_amba_port *uap =
1942 container_of(port, struct uart_amba_port, port);
1943 unsigned int lcr_h, old_cr;
1944 unsigned long flags;
1945 unsigned int baud, quot, clkdiv;
1946
1947 if (uap->vendor->oversampling)
1948 clkdiv = 8;
1949 else
1950 clkdiv = 16;
1951
1952 /*
1953 * Ask the core to calculate the divisor for us.
1954 */
1955 baud = uart_get_baud_rate(port, termios, old, 0,
1956 port->uartclk / clkdiv);
1957 #ifdef CONFIG_DMA_ENGINE
1958 /*
1959 * Adjust RX DMA polling rate with baud rate if not specified.
1960 */
1961 if (uap->dmarx.auto_poll_rate)
1962 uap->dmarx.poll_rate = DIV_ROUND_UP(10000000, baud);
1963 #endif
1964
1965 if (baud > port->uartclk/16)
1966 quot = DIV_ROUND_CLOSEST(port->uartclk * 8, baud);
1967 else
1968 quot = DIV_ROUND_CLOSEST(port->uartclk * 4, baud);
1969
1970 switch (termios->c_cflag & CSIZE) {
1971 case CS5:
1972 lcr_h = UART01x_LCRH_WLEN_5;
1973 break;
1974 case CS6:
1975 lcr_h = UART01x_LCRH_WLEN_6;
1976 break;
1977 case CS7:
1978 lcr_h = UART01x_LCRH_WLEN_7;
1979 break;
1980 default: // CS8
1981 lcr_h = UART01x_LCRH_WLEN_8;
1982 break;
1983 }
1984 if (termios->c_cflag & CSTOPB)
1985 lcr_h |= UART01x_LCRH_STP2;
1986 if (termios->c_cflag & PARENB) {
1987 lcr_h |= UART01x_LCRH_PEN;
1988 if (!(termios->c_cflag & PARODD))
1989 lcr_h |= UART01x_LCRH_EPS;
1990 if (termios->c_cflag & CMSPAR)
1991 lcr_h |= UART011_LCRH_SPS;
1992 }
1993 if (uap->fifosize > 1)
1994 lcr_h |= UART01x_LCRH_FEN;
1995
1996 spin_lock_irqsave(&port->lock, flags);
1997
1998 /*
1999 * Update the per-port timeout.
2000 */
2001 uart_update_timeout(port, termios->c_cflag, baud);
2002
2003 pl011_setup_status_masks(port, termios);
2004
2005 if (UART_ENABLE_MS(port, termios->c_cflag))
2006 pl011_enable_ms(port);
2007
2008 /* first, disable everything */
2009 old_cr = pl011_read(uap, REG_CR);
2010 pl011_write(0, uap, REG_CR);
2011
2012 if (termios->c_cflag & CRTSCTS) {
2013 if (old_cr & UART011_CR_RTS)
2014 old_cr |= UART011_CR_RTSEN;
2015
2016 old_cr |= UART011_CR_CTSEN;
2017 port->status |= UPSTAT_AUTOCTS | UPSTAT_AUTORTS;
2018 } else {
2019 old_cr &= ~(UART011_CR_CTSEN | UART011_CR_RTSEN);
2020 port->status &= ~(UPSTAT_AUTOCTS | UPSTAT_AUTORTS);
2021 }
2022
2023 if (uap->vendor->oversampling) {
2024 if (baud > port->uartclk / 16)
2025 old_cr |= ST_UART011_CR_OVSFACT;
2026 else
2027 old_cr &= ~ST_UART011_CR_OVSFACT;
2028 }
2029
2030 /*
2031 * Workaround for the ST Micro oversampling variants to
2032 * increase the bitrate slightly, by lowering the divisor,
2033 * to avoid delayed sampling of start bit at high speeds,
2034 * else we see data corruption.
2035 */
2036 if (uap->vendor->oversampling) {
2037 if ((baud >= 3000000) && (baud < 3250000) && (quot > 1))
2038 quot -= 1;
2039 else if ((baud > 3250000) && (quot > 2))
2040 quot -= 2;
2041 }
2042 /* Set baud rate */
2043 pl011_write(quot & 0x3f, uap, REG_FBRD);
2044 pl011_write(quot >> 6, uap, REG_IBRD);
2045
2046 /*
2047 * ----------v----------v----------v----------v-----
2048 * NOTE: REG_LCRH_TX and REG_LCRH_RX MUST BE WRITTEN AFTER
2049 * REG_FBRD & REG_IBRD.
2050 * ----------^----------^----------^----------^-----
2051 */
2052 pl011_write_lcr_h(uap, lcr_h);
2053 pl011_write(old_cr, uap, REG_CR);
2054
2055 spin_unlock_irqrestore(&port->lock, flags);
2056 }
2057
2058 static void
2059 sbsa_uart_set_termios(struct uart_port *port, struct ktermios *termios,
2060 struct ktermios *old)
2061 {
2062 struct uart_amba_port *uap =
2063 container_of(port, struct uart_amba_port, port);
2064 unsigned long flags;
2065
2066 tty_termios_encode_baud_rate(termios, uap->fixed_baud, uap->fixed_baud);
2067
2068 /* The SBSA UART only supports 8n1 without hardware flow control. */
2069 termios->c_cflag &= ~(CSIZE | CSTOPB | PARENB | PARODD);
2070 termios->c_cflag &= ~(CMSPAR | CRTSCTS);
2071 termios->c_cflag |= CS8 | CLOCAL;
2072
2073 spin_lock_irqsave(&port->lock, flags);
2074 uart_update_timeout(port, CS8, uap->fixed_baud);
2075 pl011_setup_status_masks(port, termios);
2076 spin_unlock_irqrestore(&port->lock, flags);
2077 }
2078
2079 static const char *pl011_type(struct uart_port *port)
2080 {
2081 struct uart_amba_port *uap =
2082 container_of(port, struct uart_amba_port, port);
2083 return uap->port.type == PORT_AMBA ? uap->type : NULL;
2084 }
2085
2086 /*
2087 * Release the memory region(s) being used by 'port'
2088 */
2089 static void pl011_release_port(struct uart_port *port)
2090 {
2091 release_mem_region(port->mapbase, SZ_4K);
2092 }
2093
2094 /*
2095 * Request the memory region(s) being used by 'port'
2096 */
2097 static int pl011_request_port(struct uart_port *port)
2098 {
2099 return request_mem_region(port->mapbase, SZ_4K, "uart-pl011")
2100 != NULL ? 0 : -EBUSY;
2101 }
2102
2103 /*
2104 * Configure/autoconfigure the port.
2105 */
2106 static void pl011_config_port(struct uart_port *port, int flags)
2107 {
2108 if (flags & UART_CONFIG_TYPE) {
2109 port->type = PORT_AMBA;
2110 pl011_request_port(port);
2111 }
2112 }
2113
2114 /*
2115 * verify the new serial_struct (for TIOCSSERIAL).
2116 */
2117 static int pl011_verify_port(struct uart_port *port, struct serial_struct *ser)
2118 {
2119 int ret = 0;
2120 if (ser->type != PORT_UNKNOWN && ser->type != PORT_AMBA)
2121 ret = -EINVAL;
2122 if (ser->irq < 0 || ser->irq >= nr_irqs)
2123 ret = -EINVAL;
2124 if (ser->baud_base < 9600)
2125 ret = -EINVAL;
2126 return ret;
2127 }
2128
2129 static const struct uart_ops amba_pl011_pops = {
2130 .tx_empty = pl011_tx_empty,
2131 .set_mctrl = pl011_set_mctrl,
2132 .get_mctrl = pl011_get_mctrl,
2133 .stop_tx = pl011_stop_tx,
2134 .start_tx = pl011_start_tx,
2135 .stop_rx = pl011_stop_rx,
2136 .enable_ms = pl011_enable_ms,
2137 .break_ctl = pl011_break_ctl,
2138 .startup = pl011_startup,
2139 .shutdown = pl011_shutdown,
2140 .flush_buffer = pl011_dma_flush_buffer,
2141 .set_termios = pl011_set_termios,
2142 .type = pl011_type,
2143 .release_port = pl011_release_port,
2144 .request_port = pl011_request_port,
2145 .config_port = pl011_config_port,
2146 .verify_port = pl011_verify_port,
2147 #ifdef CONFIG_CONSOLE_POLL
2148 .poll_init = pl011_hwinit,
2149 .poll_get_char = pl011_get_poll_char,
2150 .poll_put_char = pl011_put_poll_char,
2151 #endif
2152 };
2153
2154 static void sbsa_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
2155 {
2156 }
2157
2158 static unsigned int sbsa_uart_get_mctrl(struct uart_port *port)
2159 {
2160 return 0;
2161 }
2162
2163 static const struct uart_ops sbsa_uart_pops = {
2164 .tx_empty = pl011_tx_empty,
2165 .set_mctrl = sbsa_uart_set_mctrl,
2166 .get_mctrl = sbsa_uart_get_mctrl,
2167 .stop_tx = pl011_stop_tx,
2168 .start_tx = pl011_start_tx,
2169 .stop_rx = pl011_stop_rx,
2170 .startup = sbsa_uart_startup,
2171 .shutdown = sbsa_uart_shutdown,
2172 .set_termios = sbsa_uart_set_termios,
2173 .type = pl011_type,
2174 .release_port = pl011_release_port,
2175 .request_port = pl011_request_port,
2176 .config_port = pl011_config_port,
2177 .verify_port = pl011_verify_port,
2178 #ifdef CONFIG_CONSOLE_POLL
2179 .poll_init = pl011_hwinit,
2180 .poll_get_char = pl011_get_poll_char,
2181 .poll_put_char = pl011_put_poll_char,
2182 #endif
2183 };
2184
2185 static struct uart_amba_port *amba_ports[UART_NR];
2186
2187 #ifdef CONFIG_SERIAL_AMBA_PL011_CONSOLE
2188
2189 static void pl011_console_putchar(struct uart_port *port, int ch)
2190 {
2191 struct uart_amba_port *uap =
2192 container_of(port, struct uart_amba_port, port);
2193
2194 while (pl011_read(uap, REG_FR) & UART01x_FR_TXFF)
2195 cpu_relax();
2196 pl011_write(ch, uap, REG_DR);
2197 }
2198
2199 static void
2200 pl011_console_write(struct console *co, const char *s, unsigned int count)
2201 {
2202 struct uart_amba_port *uap = amba_ports[co->index];
2203 unsigned int old_cr = 0, new_cr;
2204 unsigned long flags;
2205 int locked = 1;
2206
2207 clk_enable(uap->clk);
2208
2209 local_irq_save(flags);
2210 if (uap->port.sysrq)
2211 locked = 0;
2212 else if (oops_in_progress)
2213 locked = spin_trylock(&uap->port.lock);
2214 else
2215 spin_lock(&uap->port.lock);
2216
2217 /*
2218 * First save the CR then disable the interrupts
2219 */
2220 if (!uap->vendor->always_enabled) {
2221 old_cr = pl011_read(uap, REG_CR);
2222 new_cr = old_cr & ~UART011_CR_CTSEN;
2223 new_cr |= UART01x_CR_UARTEN | UART011_CR_TXE;
2224 pl011_write(new_cr, uap, REG_CR);
2225 }
2226
2227 uart_console_write(&uap->port, s, count, pl011_console_putchar);
2228
2229 /*
2230 * Finally, wait for transmitter to become empty and restore the
2231 * TCR. Allow feature register bits to be inverted to work around
2232 * errata.
2233 */
2234 while ((pl011_read(uap, REG_FR) ^ uap->vendor->inv_fr)
2235 & uap->vendor->fr_busy)
2236 cpu_relax();
2237 if (!uap->vendor->always_enabled)
2238 pl011_write(old_cr, uap, REG_CR);
2239
2240 if (locked)
2241 spin_unlock(&uap->port.lock);
2242 local_irq_restore(flags);
2243
2244 clk_disable(uap->clk);
2245 }
2246
2247 static void pl011_console_get_options(struct uart_amba_port *uap, int *baud,
2248 int *parity, int *bits)
2249 {
2250 if (pl011_read(uap, REG_CR) & UART01x_CR_UARTEN) {
2251 unsigned int lcr_h, ibrd, fbrd;
2252
2253 lcr_h = pl011_read(uap, REG_LCRH_TX);
2254
2255 *parity = 'n';
2256 if (lcr_h & UART01x_LCRH_PEN) {
2257 if (lcr_h & UART01x_LCRH_EPS)
2258 *parity = 'e';
2259 else
2260 *parity = 'o';
2261 }
2262
2263 if ((lcr_h & 0x60) == UART01x_LCRH_WLEN_7)
2264 *bits = 7;
2265 else
2266 *bits = 8;
2267
2268 ibrd = pl011_read(uap, REG_IBRD);
2269 fbrd = pl011_read(uap, REG_FBRD);
2270
2271 *baud = uap->port.uartclk * 4 / (64 * ibrd + fbrd);
2272
2273 if (uap->vendor->oversampling) {
2274 if (pl011_read(uap, REG_CR)
2275 & ST_UART011_CR_OVSFACT)
2276 *baud *= 2;
2277 }
2278 }
2279 }
2280
2281 static int pl011_console_setup(struct console *co, char *options)
2282 {
2283 struct uart_amba_port *uap;
2284 int baud = 38400;
2285 int bits = 8;
2286 int parity = 'n';
2287 int flow = 'n';
2288 int ret;
2289
2290 /*
2291 * Check whether an invalid uart number has been specified, and
2292 * if so, search for the first available port that does have
2293 * console support.
2294 */
2295 if (co->index >= UART_NR)
2296 co->index = 0;
2297 uap = amba_ports[co->index];
2298 if (!uap)
2299 return -ENODEV;
2300
2301 /* Allow pins to be muxed in and configured */
2302 pinctrl_pm_select_default_state(uap->port.dev);
2303
2304 ret = clk_prepare(uap->clk);
2305 if (ret)
2306 return ret;
2307
2308 if (dev_get_platdata(uap->port.dev)) {
2309 struct amba_pl011_data *plat;
2310
2311 plat = dev_get_platdata(uap->port.dev);
2312 if (plat->init)
2313 plat->init();
2314 }
2315
2316 uap->port.uartclk = clk_get_rate(uap->clk);
2317
2318 if (uap->vendor->fixed_options) {
2319 baud = uap->fixed_baud;
2320 } else {
2321 if (options)
2322 uart_parse_options(options,
2323 &baud, &parity, &bits, &flow);
2324 else
2325 pl011_console_get_options(uap, &baud, &parity, &bits);
2326 }
2327
2328 return uart_set_options(&uap->port, co, baud, parity, bits, flow);
2329 }
2330
2331 /**
2332 * pl011_console_match - non-standard console matching
2333 * @co: registering console
2334 * @name: name from console command line
2335 * @idx: index from console command line
2336 * @options: ptr to option string from console command line
2337 *
2338 * Only attempts to match console command lines of the form:
2339 * console=pl011,mmio|mmio32,<addr>[,<options>]
2340 * console=pl011,0x<addr>[,<options>]
2341 * This form is used to register an initial earlycon boot console and
2342 * replace it with the amba_console at pl011 driver init.
2343 *
2344 * Performs console setup for a match (as required by interface)
2345 * If no <options> are specified, then assume the h/w is already setup.
2346 *
2347 * Returns 0 if console matches; otherwise non-zero to use default matching
2348 */
2349 static int pl011_console_match(struct console *co, char *name, int idx,
2350 char *options)
2351 {
2352 unsigned char iotype;
2353 resource_size_t addr;
2354 int i;
2355
2356 /*
2357 * Systems affected by the Qualcomm Technologies QDF2400 E44 erratum
2358 * have a distinct console name, so make sure we check for that.
2359 * The actual implementation of the erratum occurs in the probe
2360 * function.
2361 */
2362 if ((strcmp(name, "qdf2400_e44") != 0) && (strcmp(name, "pl011") != 0))
2363 return -ENODEV;
2364
2365 if (uart_parse_earlycon(options, &iotype, &addr, &options))
2366 return -ENODEV;
2367
2368 if (iotype != UPIO_MEM && iotype != UPIO_MEM32)
2369 return -ENODEV;
2370
2371 /* try to match the port specified on the command line */
2372 for (i = 0; i < ARRAY_SIZE(amba_ports); i++) {
2373 struct uart_port *port;
2374
2375 if (!amba_ports[i])
2376 continue;
2377
2378 port = &amba_ports[i]->port;
2379
2380 if (port->mapbase != addr)
2381 continue;
2382
2383 co->index = i;
2384 port->cons = co;
2385 return pl011_console_setup(co, options);
2386 }
2387
2388 return -ENODEV;
2389 }
2390
2391 static struct uart_driver amba_reg;
2392 static struct console amba_console = {
2393 .name = "ttyAMA",
2394 .write = pl011_console_write,
2395 .device = uart_console_device,
2396 .setup = pl011_console_setup,
2397 .match = pl011_console_match,
2398 .flags = CON_PRINTBUFFER | CON_ANYTIME,
2399 .index = -1,
2400 .data = &amba_reg,
2401 };
2402
2403 #define AMBA_CONSOLE (&amba_console)
2404
2405 static void qdf2400_e44_putc(struct uart_port *port, int c)
2406 {
2407 while (readl(port->membase + UART01x_FR) & UART01x_FR_TXFF)
2408 cpu_relax();
2409 writel(c, port->membase + UART01x_DR);
2410 while (!(readl(port->membase + UART01x_FR) & UART011_FR_TXFE))
2411 cpu_relax();
2412 }
2413
2414 static void qdf2400_e44_early_write(struct console *con, const char *s, unsigned n)
2415 {
2416 struct earlycon_device *dev = con->data;
2417
2418 uart_console_write(&dev->port, s, n, qdf2400_e44_putc);
2419 }
2420
2421 static void pl011_putc(struct uart_port *port, int c)
2422 {
2423 while (readl(port->membase + UART01x_FR) & UART01x_FR_TXFF)
2424 cpu_relax();
2425 if (port->iotype == UPIO_MEM32)
2426 writel(c, port->membase + UART01x_DR);
2427 else
2428 writeb(c, port->membase + UART01x_DR);
2429 while (readl(port->membase + UART01x_FR) & UART01x_FR_BUSY)
2430 cpu_relax();
2431 }
2432
2433 static void pl011_early_write(struct console *con, const char *s, unsigned n)
2434 {
2435 struct earlycon_device *dev = con->data;
2436
2437 uart_console_write(&dev->port, s, n, pl011_putc);
2438 }
2439
2440 #ifdef CONFIG_CONSOLE_POLL
2441 static int pl011_getc(struct uart_port *port)
2442 {
2443 if (readl(port->membase + UART01x_FR) & UART01x_FR_RXFE)
2444 return NO_POLL_CHAR;
2445
2446 if (port->iotype == UPIO_MEM32)
2447 return readl(port->membase + UART01x_DR);
2448 else
2449 return readb(port->membase + UART01x_DR);
2450 }
2451
2452 static int pl011_early_read(struct console *con, char *s, unsigned int n)
2453 {
2454 struct earlycon_device *dev = con->data;
2455 int ch, num_read = 0;
2456
2457 while (num_read < n) {
2458 ch = pl011_getc(&dev->port);
2459 if (ch == NO_POLL_CHAR)
2460 break;
2461
2462 s[num_read++] = ch;
2463 }
2464
2465 return num_read;
2466 }
2467 #else
2468 #define pl011_early_read NULL
2469 #endif
2470
2471 /*
2472 * On non-ACPI systems, earlycon is enabled by specifying
2473 * "earlycon=pl011,<address>" on the kernel command line.
2474 *
2475 * On ACPI ARM64 systems, an "early" console is enabled via the SPCR table,
2476 * by specifying only "earlycon" on the command line. Because it requires
2477 * SPCR, the console starts after ACPI is parsed, which is later than a
2478 * traditional early console.
2479 *
2480 * To get the traditional early console that starts before ACPI is parsed,
2481 * specify the full "earlycon=pl011,<address>" option.
2482 */
2483 static int __init pl011_early_console_setup(struct earlycon_device *device,
2484 const char *opt)
2485 {
2486 if (!device->port.membase)
2487 return -ENODEV;
2488
2489 device->con->write = pl011_early_write;
2490 device->con->read = pl011_early_read;
2491
2492 return 0;
2493 }
2494 OF_EARLYCON_DECLARE(pl011, "arm,pl011", pl011_early_console_setup);
2495 OF_EARLYCON_DECLARE(pl011, "arm,sbsa-uart", pl011_early_console_setup);
2496
2497 /*
2498 * On Qualcomm Datacenter Technologies QDF2400 SOCs affected by
2499 * Erratum 44, traditional earlycon can be enabled by specifying
2500 * "earlycon=qdf2400_e44,<address>". Any options are ignored.
2501 *
2502 * Alternatively, you can just specify "earlycon", and the early console
2503 * will be enabled with the information from the SPCR table. In this
2504 * case, the SPCR code will detect the need for the E44 work-around,
2505 * and set the console name to "qdf2400_e44".
2506 */
2507 static int __init
2508 qdf2400_e44_early_console_setup(struct earlycon_device *device,
2509 const char *opt)
2510 {
2511 if (!device->port.membase)
2512 return -ENODEV;
2513
2514 device->con->write = qdf2400_e44_early_write;
2515 return 0;
2516 }
2517 EARLYCON_DECLARE(qdf2400_e44, qdf2400_e44_early_console_setup);
2518
2519 #else
2520 #define AMBA_CONSOLE NULL
2521 #endif
2522
2523 static struct uart_driver amba_reg = {
2524 .owner = THIS_MODULE,
2525 .driver_name = "ttyAMA",
2526 .dev_name = "ttyAMA",
2527 .major = SERIAL_AMBA_MAJOR,
2528 .minor = SERIAL_AMBA_MINOR,
2529 .nr = UART_NR,
2530 .cons = AMBA_CONSOLE,
2531 };
2532
2533 static int pl011_probe_dt_alias(int index, struct device *dev)
2534 {
2535 struct device_node *np;
2536 static bool seen_dev_with_alias = false;
2537 static bool seen_dev_without_alias = false;
2538 int ret = index;
2539
2540 if (!IS_ENABLED(CONFIG_OF))
2541 return ret;
2542
2543 np = dev->of_node;
2544 if (!np)
2545 return ret;
2546
2547 ret = of_alias_get_id(np, "serial");
2548 if (ret < 0) {
2549 seen_dev_without_alias = true;
2550 ret = index;
2551 } else {
2552 seen_dev_with_alias = true;
2553 if (ret >= ARRAY_SIZE(amba_ports) || amba_ports[ret] != NULL) {
2554 dev_warn(dev, "requested serial port %d not available.\n", ret);
2555 ret = index;
2556 }
2557 }
2558
2559 if (seen_dev_with_alias && seen_dev_without_alias)
2560 dev_warn(dev, "aliased and non-aliased serial devices found in device tree. Serial port enumeration may be unpredictable.\n");
2561
2562 return ret;
2563 }
2564
2565 /* unregisters the driver also if no more ports are left */
2566 static void pl011_unregister_port(struct uart_amba_port *uap)
2567 {
2568 int i;
2569 bool busy = false;
2570
2571 for (i = 0; i < ARRAY_SIZE(amba_ports); i++) {
2572 if (amba_ports[i] == uap)
2573 amba_ports[i] = NULL;
2574 else if (amba_ports[i])
2575 busy = true;
2576 }
2577 pl011_dma_remove(uap);
2578 if (!busy)
2579 uart_unregister_driver(&amba_reg);
2580 }
2581
2582 static int pl011_find_free_port(void)
2583 {
2584 int i;
2585
2586 for (i = 0; i < ARRAY_SIZE(amba_ports); i++)
2587 if (amba_ports[i] == NULL)
2588 return i;
2589
2590 return -EBUSY;
2591 }
2592
2593 static int pl011_setup_port(struct device *dev, struct uart_amba_port *uap,
2594 struct resource *mmiobase, int index)
2595 {
2596 void __iomem *base;
2597
2598 base = devm_ioremap_resource(dev, mmiobase);
2599 if (IS_ERR(base))
2600 return PTR_ERR(base);
2601
2602 index = pl011_probe_dt_alias(index, dev);
2603
2604 uap->old_cr = 0;
2605 uap->port.dev = dev;
2606 uap->port.mapbase = mmiobase->start;
2607 uap->port.membase = base;
2608 uap->port.fifosize = uap->fifosize;
2609 uap->port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_AMBA_PL011_CONSOLE);
2610 uap->port.flags = UPF_BOOT_AUTOCONF;
2611 uap->port.line = index;
2612
2613 amba_ports[index] = uap;
2614
2615 return 0;
2616 }
2617
2618 static int pl011_register_port(struct uart_amba_port *uap)
2619 {
2620 int ret, i;
2621
2622 /* Ensure interrupts from this UART are masked and cleared */
2623 pl011_write(0, uap, REG_IMSC);
2624 pl011_write(0xffff, uap, REG_ICR);
2625
2626 if (!amba_reg.state) {
2627 ret = uart_register_driver(&amba_reg);
2628 if (ret < 0) {
2629 dev_err(uap->port.dev,
2630 "Failed to register AMBA-PL011 driver\n");
2631 for (i = 0; i < ARRAY_SIZE(amba_ports); i++)
2632 if (amba_ports[i] == uap)
2633 amba_ports[i] = NULL;
2634 return ret;
2635 }
2636 }
2637
2638 ret = uart_add_one_port(&amba_reg, &uap->port);
2639 if (ret)
2640 pl011_unregister_port(uap);
2641
2642 return ret;
2643 }
2644
2645 static int pl011_probe(struct amba_device *dev, const struct amba_id *id)
2646 {
2647 struct uart_amba_port *uap;
2648 struct vendor_data *vendor = id->data;
2649 int portnr, ret;
2650
2651 portnr = pl011_find_free_port();
2652 if (portnr < 0)
2653 return portnr;
2654
2655 uap = devm_kzalloc(&dev->dev, sizeof(struct uart_amba_port),
2656 GFP_KERNEL);
2657 if (!uap)
2658 return -ENOMEM;
2659
2660 uap->clk = devm_clk_get(&dev->dev, NULL);
2661 if (IS_ERR(uap->clk))
2662 return PTR_ERR(uap->clk);
2663
2664 uap->reg_offset = vendor->reg_offset;
2665 uap->vendor = vendor;
2666 uap->fifosize = vendor->get_fifosize(dev);
2667 uap->port.iotype = vendor->access_32b ? UPIO_MEM32 : UPIO_MEM;
2668 uap->port.irq = dev->irq[0];
2669 uap->port.ops = &amba_pl011_pops;
2670
2671 snprintf(uap->type, sizeof(uap->type), "PL011 rev%u", amba_rev(dev));
2672
2673 ret = pl011_setup_port(&dev->dev, uap, &dev->res, portnr);
2674 if (ret)
2675 return ret;
2676
2677 amba_set_drvdata(dev, uap);
2678
2679 return pl011_register_port(uap);
2680 }
2681
2682 static int pl011_remove(struct amba_device *dev)
2683 {
2684 struct uart_amba_port *uap = amba_get_drvdata(dev);
2685
2686 uart_remove_one_port(&amba_reg, &uap->port);
2687 pl011_unregister_port(uap);
2688 return 0;
2689 }
2690
2691 #ifdef CONFIG_PM_SLEEP
2692 static int pl011_suspend(struct device *dev)
2693 {
2694 struct uart_amba_port *uap = dev_get_drvdata(dev);
2695
2696 if (!uap)
2697 return -EINVAL;
2698
2699 return uart_suspend_port(&amba_reg, &uap->port);
2700 }
2701
2702 static int pl011_resume(struct device *dev)
2703 {
2704 struct uart_amba_port *uap = dev_get_drvdata(dev);
2705
2706 if (!uap)
2707 return -EINVAL;
2708
2709 return uart_resume_port(&amba_reg, &uap->port);
2710 }
2711 #endif
2712
2713 static SIMPLE_DEV_PM_OPS(pl011_dev_pm_ops, pl011_suspend, pl011_resume);
2714
2715 static int sbsa_uart_probe(struct platform_device *pdev)
2716 {
2717 struct uart_amba_port *uap;
2718 struct resource *r;
2719 int portnr, ret;
2720 int baudrate;
2721
2722 /*
2723 * Check the mandatory baud rate parameter in the DT node early
2724 * so that we can easily exit with the error.
2725 */
2726 if (pdev->dev.of_node) {
2727 struct device_node *np = pdev->dev.of_node;
2728
2729 ret = of_property_read_u32(np, "current-speed", &baudrate);
2730 if (ret)
2731 return ret;
2732 } else {
2733 baudrate = 115200;
2734 }
2735
2736 portnr = pl011_find_free_port();
2737 if (portnr < 0)
2738 return portnr;
2739
2740 uap = devm_kzalloc(&pdev->dev, sizeof(struct uart_amba_port),
2741 GFP_KERNEL);
2742 if (!uap)
2743 return -ENOMEM;
2744
2745 ret = platform_get_irq(pdev, 0);
2746 if (ret < 0)
2747 return ret;
2748 uap->port.irq = ret;
2749
2750 #ifdef CONFIG_ACPI_SPCR_TABLE
2751 if (qdf2400_e44_present) {
2752 dev_info(&pdev->dev, "working around QDF2400 SoC erratum 44\n");
2753 uap->vendor = &vendor_qdt_qdf2400_e44;
2754 } else
2755 #endif
2756 uap->vendor = &vendor_sbsa;
2757
2758 uap->reg_offset = uap->vendor->reg_offset;
2759 uap->fifosize = 32;
2760 uap->port.iotype = uap->vendor->access_32b ? UPIO_MEM32 : UPIO_MEM;
2761 uap->port.ops = &sbsa_uart_pops;
2762 uap->fixed_baud = baudrate;
2763
2764 snprintf(uap->type, sizeof(uap->type), "SBSA");
2765
2766 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
2767
2768 ret = pl011_setup_port(&pdev->dev, uap, r, portnr);
2769 if (ret)
2770 return ret;
2771
2772 platform_set_drvdata(pdev, uap);
2773
2774 return pl011_register_port(uap);
2775 }
2776
2777 static int sbsa_uart_remove(struct platform_device *pdev)
2778 {
2779 struct uart_amba_port *uap = platform_get_drvdata(pdev);
2780
2781 uart_remove_one_port(&amba_reg, &uap->port);
2782 pl011_unregister_port(uap);
2783 return 0;
2784 }
2785
2786 static const struct of_device_id sbsa_uart_of_match[] = {
2787 { .compatible = "arm,sbsa-uart", },
2788 {},
2789 };
2790 MODULE_DEVICE_TABLE(of, sbsa_uart_of_match);
2791
2792 static const struct acpi_device_id __maybe_unused sbsa_uart_acpi_match[] = {
2793 { "ARMH0011", 0 },
2794 {},
2795 };
2796 MODULE_DEVICE_TABLE(acpi, sbsa_uart_acpi_match);
2797
2798 static struct platform_driver arm_sbsa_uart_platform_driver = {
2799 .probe = sbsa_uart_probe,
2800 .remove = sbsa_uart_remove,
2801 .driver = {
2802 .name = "sbsa-uart",
2803 .pm = &pl011_dev_pm_ops,
2804 .of_match_table = of_match_ptr(sbsa_uart_of_match),
2805 .acpi_match_table = ACPI_PTR(sbsa_uart_acpi_match),
2806 .suppress_bind_attrs = IS_BUILTIN(CONFIG_SERIAL_AMBA_PL011),
2807 },
2808 };
2809
2810 static const struct amba_id pl011_ids[] = {
2811 {
2812 .id = 0x00041011,
2813 .mask = 0x000fffff,
2814 .data = &vendor_arm,
2815 },
2816 {
2817 .id = 0x00380802,
2818 .mask = 0x00ffffff,
2819 .data = &vendor_st,
2820 },
2821 {
2822 .id = AMBA_LINUX_ID(0x00, 0x1, 0xffe),
2823 .mask = 0x00ffffff,
2824 .data = &vendor_zte,
2825 },
2826 { 0, 0 },
2827 };
2828
2829 MODULE_DEVICE_TABLE(amba, pl011_ids);
2830
2831 static struct amba_driver pl011_driver = {
2832 .drv = {
2833 .name = "uart-pl011",
2834 .pm = &pl011_dev_pm_ops,
2835 .suppress_bind_attrs = IS_BUILTIN(CONFIG_SERIAL_AMBA_PL011),
2836 },
2837 .id_table = pl011_ids,
2838 .probe = pl011_probe,
2839 .remove = pl011_remove,
2840 };
2841
2842 static int __init pl011_init(void)
2843 {
2844 printk(KERN_INFO "Serial: AMBA PL011 UART driver\n");
2845
2846 if (platform_driver_register(&arm_sbsa_uart_platform_driver))
2847 pr_warn("could not register SBSA UART platform driver\n");
2848 return amba_driver_register(&pl011_driver);
2849 }
2850
2851 static void __exit pl011_exit(void)
2852 {
2853 platform_driver_unregister(&arm_sbsa_uart_platform_driver);
2854 amba_driver_unregister(&pl011_driver);
2855 }
2856
2857 /*
2858 * While this can be a module, if builtin it's most likely the console
2859 * So let's leave module_exit but move module_init to an earlier place
2860 */
2861 arch_initcall(pl011_init);
2862 module_exit(pl011_exit);
2863
2864 MODULE_AUTHOR("ARM Ltd/Deep Blue Solutions Ltd");
2865 MODULE_DESCRIPTION("ARM AMBA serial port driver");
2866 MODULE_LICENSE("GPL");
Linux with added FPC-III support