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Linux 4.19.133
[linux/fpc-iii.git] / drivers / tty / serial / msm_serial.c
blob4caeca67fd1435cea7d68f3aac511545c5354000
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Driver for msm7k serial device and console
4 *
5 * Copyright (C) 2007 Google, Inc.
6 * Author: Robert Love <rlove@google.com>
7 * Copyright (c) 2011, Code Aurora Forum. All rights reserved.
8 */
9
10 #if defined(CONFIG_SERIAL_MSM_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
11 # define SUPPORT_SYSRQ
12 #endif
13
14 #include <linux/kernel.h>
15 #include <linux/atomic.h>
16 #include <linux/dma-mapping.h>
17 #include <linux/dmaengine.h>
18 #include <linux/module.h>
19 #include <linux/io.h>
20 #include <linux/ioport.h>
21 #include <linux/interrupt.h>
22 #include <linux/init.h>
23 #include <linux/console.h>
24 #include <linux/tty.h>
25 #include <linux/tty_flip.h>
26 #include <linux/serial_core.h>
27 #include <linux/slab.h>
28 #include <linux/clk.h>
29 #include <linux/platform_device.h>
30 #include <linux/delay.h>
31 #include <linux/of.h>
32 #include <linux/of_device.h>
33 #include <linux/wait.h>
34
35 #define UART_MR1 0x0000
36
37 #define UART_MR1_AUTO_RFR_LEVEL0 0x3F
38 #define UART_MR1_AUTO_RFR_LEVEL1 0x3FF00
39 #define UART_DM_MR1_AUTO_RFR_LEVEL1 0xFFFFFF00
40 #define UART_MR1_RX_RDY_CTL BIT(7)
41 #define UART_MR1_CTS_CTL BIT(6)
42
43 #define UART_MR2 0x0004
44 #define UART_MR2_ERROR_MODE BIT(6)
45 #define UART_MR2_BITS_PER_CHAR 0x30
46 #define UART_MR2_BITS_PER_CHAR_5 (0x0 << 4)
47 #define UART_MR2_BITS_PER_CHAR_6 (0x1 << 4)
48 #define UART_MR2_BITS_PER_CHAR_7 (0x2 << 4)
49 #define UART_MR2_BITS_PER_CHAR_8 (0x3 << 4)
50 #define UART_MR2_STOP_BIT_LEN_ONE (0x1 << 2)
51 #define UART_MR2_STOP_BIT_LEN_TWO (0x3 << 2)
52 #define UART_MR2_PARITY_MODE_NONE 0x0
53 #define UART_MR2_PARITY_MODE_ODD 0x1
54 #define UART_MR2_PARITY_MODE_EVEN 0x2
55 #define UART_MR2_PARITY_MODE_SPACE 0x3
56 #define UART_MR2_PARITY_MODE 0x3
57
58 #define UART_CSR 0x0008
59
60 #define UART_TF 0x000C
61 #define UARTDM_TF 0x0070
62
63 #define UART_CR 0x0010
64 #define UART_CR_CMD_NULL (0 << 4)
65 #define UART_CR_CMD_RESET_RX (1 << 4)
66 #define UART_CR_CMD_RESET_TX (2 << 4)
67 #define UART_CR_CMD_RESET_ERR (3 << 4)
68 #define UART_CR_CMD_RESET_BREAK_INT (4 << 4)
69 #define UART_CR_CMD_START_BREAK (5 << 4)
70 #define UART_CR_CMD_STOP_BREAK (6 << 4)
71 #define UART_CR_CMD_RESET_CTS (7 << 4)
72 #define UART_CR_CMD_RESET_STALE_INT (8 << 4)
73 #define UART_CR_CMD_PACKET_MODE (9 << 4)
74 #define UART_CR_CMD_MODE_RESET (12 << 4)
75 #define UART_CR_CMD_SET_RFR (13 << 4)
76 #define UART_CR_CMD_RESET_RFR (14 << 4)
77 #define UART_CR_CMD_PROTECTION_EN (16 << 4)
78 #define UART_CR_CMD_STALE_EVENT_DISABLE (6 << 8)
79 #define UART_CR_CMD_STALE_EVENT_ENABLE (80 << 4)
80 #define UART_CR_CMD_FORCE_STALE (4 << 8)
81 #define UART_CR_CMD_RESET_TX_READY (3 << 8)
82 #define UART_CR_TX_DISABLE BIT(3)
83 #define UART_CR_TX_ENABLE BIT(2)
84 #define UART_CR_RX_DISABLE BIT(1)
85 #define UART_CR_RX_ENABLE BIT(0)
86 #define UART_CR_CMD_RESET_RXBREAK_START ((1 << 11) | (2 << 4))
87
88 #define UART_IMR 0x0014
89 #define UART_IMR_TXLEV BIT(0)
90 #define UART_IMR_RXSTALE BIT(3)
91 #define UART_IMR_RXLEV BIT(4)
92 #define UART_IMR_DELTA_CTS BIT(5)
93 #define UART_IMR_CURRENT_CTS BIT(6)
94 #define UART_IMR_RXBREAK_START BIT(10)
95
96 #define UART_IPR_RXSTALE_LAST 0x20
97 #define UART_IPR_STALE_LSB 0x1F
98 #define UART_IPR_STALE_TIMEOUT_MSB 0x3FF80
99 #define UART_DM_IPR_STALE_TIMEOUT_MSB 0xFFFFFF80
100
101 #define UART_IPR 0x0018
102 #define UART_TFWR 0x001C
103 #define UART_RFWR 0x0020
104 #define UART_HCR 0x0024
105
106 #define UART_MREG 0x0028
107 #define UART_NREG 0x002C
108 #define UART_DREG 0x0030
109 #define UART_MNDREG 0x0034
110 #define UART_IRDA 0x0038
111 #define UART_MISR_MODE 0x0040
112 #define UART_MISR_RESET 0x0044
113 #define UART_MISR_EXPORT 0x0048
114 #define UART_MISR_VAL 0x004C
115 #define UART_TEST_CTRL 0x0050
116
117 #define UART_SR 0x0008
118 #define UART_SR_HUNT_CHAR BIT(7)
119 #define UART_SR_RX_BREAK BIT(6)
120 #define UART_SR_PAR_FRAME_ERR BIT(5)
121 #define UART_SR_OVERRUN BIT(4)
122 #define UART_SR_TX_EMPTY BIT(3)
123 #define UART_SR_TX_READY BIT(2)
124 #define UART_SR_RX_FULL BIT(1)
125 #define UART_SR_RX_READY BIT(0)
126
127 #define UART_RF 0x000C
128 #define UARTDM_RF 0x0070
129 #define UART_MISR 0x0010
130 #define UART_ISR 0x0014
131 #define UART_ISR_TX_READY BIT(7)
132
133 #define UARTDM_RXFS 0x50
134 #define UARTDM_RXFS_BUF_SHIFT 0x7
135 #define UARTDM_RXFS_BUF_MASK 0x7
136
137 #define UARTDM_DMEN 0x3C
138 #define UARTDM_DMEN_RX_SC_ENABLE BIT(5)
139 #define UARTDM_DMEN_TX_SC_ENABLE BIT(4)
140
141 #define UARTDM_DMEN_TX_BAM_ENABLE BIT(2) /* UARTDM_1P4 */
142 #define UARTDM_DMEN_TX_DM_ENABLE BIT(0) /* < UARTDM_1P4 */
143
144 #define UARTDM_DMEN_RX_BAM_ENABLE BIT(3) /* UARTDM_1P4 */
145 #define UARTDM_DMEN_RX_DM_ENABLE BIT(1) /* < UARTDM_1P4 */
146
147 #define UARTDM_DMRX 0x34
148 #define UARTDM_NCF_TX 0x40
149 #define UARTDM_RX_TOTAL_SNAP 0x38
150
151 #define UARTDM_BURST_SIZE 16 /* in bytes */
152 #define UARTDM_TX_AIGN(x) ((x) & ~0x3) /* valid for > 1p3 */
153 #define UARTDM_TX_MAX 256 /* in bytes, valid for <= 1p3 */
154 #define UARTDM_RX_SIZE (UART_XMIT_SIZE / 4)
155
156 enum {
157 UARTDM_1P1 = 1,
158 UARTDM_1P2,
159 UARTDM_1P3,
160 UARTDM_1P4,
161 };
162
163 struct msm_dma {
164 struct dma_chan *chan;
165 enum dma_data_direction dir;
166 dma_addr_t phys;
167 unsigned char *virt;
168 dma_cookie_t cookie;
169 u32 enable_bit;
170 unsigned int count;
171 struct dma_async_tx_descriptor *desc;
172 };
173
174 struct msm_port {
175 struct uart_port uart;
176 char name[16];
177 struct clk *clk;
178 struct clk *pclk;
179 unsigned int imr;
180 int is_uartdm;
181 unsigned int old_snap_state;
182 bool break_detected;
183 struct msm_dma tx_dma;
184 struct msm_dma rx_dma;
185 };
186
187 #define UART_TO_MSM(uart_port) container_of(uart_port, struct msm_port, uart)
188
189 static
190 void msm_write(struct uart_port *port, unsigned int val, unsigned int off)
191 {
192 writel_relaxed(val, port->membase + off);
193 }
194
195 static
196 unsigned int msm_read(struct uart_port *port, unsigned int off)
197 {
198 return readl_relaxed(port->membase + off);
199 }
200
201 /*
202 * Setup the MND registers to use the TCXO clock.
203 */
204 static void msm_serial_set_mnd_regs_tcxo(struct uart_port *port)
205 {
206 msm_write(port, 0x06, UART_MREG);
207 msm_write(port, 0xF1, UART_NREG);
208 msm_write(port, 0x0F, UART_DREG);
209 msm_write(port, 0x1A, UART_MNDREG);
210 port->uartclk = 1843200;
211 }
212
213 /*
214 * Setup the MND registers to use the TCXO clock divided by 4.
215 */
216 static void msm_serial_set_mnd_regs_tcxoby4(struct uart_port *port)
217 {
218 msm_write(port, 0x18, UART_MREG);
219 msm_write(port, 0xF6, UART_NREG);
220 msm_write(port, 0x0F, UART_DREG);
221 msm_write(port, 0x0A, UART_MNDREG);
222 port->uartclk = 1843200;
223 }
224
225 static void msm_serial_set_mnd_regs(struct uart_port *port)
226 {
227 struct msm_port *msm_port = UART_TO_MSM(port);
228
229 /*
230 * These registers don't exist so we change the clk input rate
231 * on uartdm hardware instead
232 */
233 if (msm_port->is_uartdm)
234 return;
235
236 if (port->uartclk == 19200000)
237 msm_serial_set_mnd_regs_tcxo(port);
238 else if (port->uartclk == 4800000)
239 msm_serial_set_mnd_regs_tcxoby4(port);
240 }
241
242 static void msm_handle_tx(struct uart_port *port);
243 static void msm_start_rx_dma(struct msm_port *msm_port);
244
245 static void msm_stop_dma(struct uart_port *port, struct msm_dma *dma)
246 {
247 struct device *dev = port->dev;
248 unsigned int mapped;
249 u32 val;
250
251 mapped = dma->count;
252 dma->count = 0;
253
254 dmaengine_terminate_all(dma->chan);
255
256 /*
257 * DMA Stall happens if enqueue and flush command happens concurrently.
258 * For example before changing the baud rate/protocol configuration and
259 * sending flush command to ADM, disable the channel of UARTDM.
260 * Note: should not reset the receiver here immediately as it is not
261 * suggested to do disable/reset or reset/disable at the same time.
262 */
263 val = msm_read(port, UARTDM_DMEN);
264 val &= ~dma->enable_bit;
265 msm_write(port, val, UARTDM_DMEN);
266
267 if (mapped)
268 dma_unmap_single(dev, dma->phys, mapped, dma->dir);
269 }
270
271 static void msm_release_dma(struct msm_port *msm_port)
272 {
273 struct msm_dma *dma;
274
275 dma = &msm_port->tx_dma;
276 if (dma->chan) {
277 msm_stop_dma(&msm_port->uart, dma);
278 dma_release_channel(dma->chan);
279 }
280
281 memset(dma, 0, sizeof(*dma));
282
283 dma = &msm_port->rx_dma;
284 if (dma->chan) {
285 msm_stop_dma(&msm_port->uart, dma);
286 dma_release_channel(dma->chan);
287 kfree(dma->virt);
288 }
289
290 memset(dma, 0, sizeof(*dma));
291 }
292
293 static void msm_request_tx_dma(struct msm_port *msm_port, resource_size_t base)
294 {
295 struct device *dev = msm_port->uart.dev;
296 struct dma_slave_config conf;
297 struct msm_dma *dma;
298 u32 crci = 0;
299 int ret;
300
301 dma = &msm_port->tx_dma;
302
303 /* allocate DMA resources, if available */
304 dma->chan = dma_request_slave_channel_reason(dev, "tx");
305 if (IS_ERR(dma->chan))
306 goto no_tx;
307
308 of_property_read_u32(dev->of_node, "qcom,tx-crci", &crci);
309
310 memset(&conf, 0, sizeof(conf));
311 conf.direction = DMA_MEM_TO_DEV;
312 conf.device_fc = true;
313 conf.dst_addr = base + UARTDM_TF;
314 conf.dst_maxburst = UARTDM_BURST_SIZE;
315 conf.slave_id = crci;
316
317 ret = dmaengine_slave_config(dma->chan, &conf);
318 if (ret)
319 goto rel_tx;
320
321 dma->dir = DMA_TO_DEVICE;
322
323 if (msm_port->is_uartdm < UARTDM_1P4)
324 dma->enable_bit = UARTDM_DMEN_TX_DM_ENABLE;
325 else
326 dma->enable_bit = UARTDM_DMEN_TX_BAM_ENABLE;
327
328 return;
329
330 rel_tx:
331 dma_release_channel(dma->chan);
332 no_tx:
333 memset(dma, 0, sizeof(*dma));
334 }
335
336 static void msm_request_rx_dma(struct msm_port *msm_port, resource_size_t base)
337 {
338 struct device *dev = msm_port->uart.dev;
339 struct dma_slave_config conf;
340 struct msm_dma *dma;
341 u32 crci = 0;
342 int ret;
343
344 dma = &msm_port->rx_dma;
345
346 /* allocate DMA resources, if available */
347 dma->chan = dma_request_slave_channel_reason(dev, "rx");
348 if (IS_ERR(dma->chan))
349 goto no_rx;
350
351 of_property_read_u32(dev->of_node, "qcom,rx-crci", &crci);
352
353 dma->virt = kzalloc(UARTDM_RX_SIZE, GFP_KERNEL);
354 if (!dma->virt)
355 goto rel_rx;
356
357 memset(&conf, 0, sizeof(conf));
358 conf.direction = DMA_DEV_TO_MEM;
359 conf.device_fc = true;
360 conf.src_addr = base + UARTDM_RF;
361 conf.src_maxburst = UARTDM_BURST_SIZE;
362 conf.slave_id = crci;
363
364 ret = dmaengine_slave_config(dma->chan, &conf);
365 if (ret)
366 goto err;
367
368 dma->dir = DMA_FROM_DEVICE;
369
370 if (msm_port->is_uartdm < UARTDM_1P4)
371 dma->enable_bit = UARTDM_DMEN_RX_DM_ENABLE;
372 else
373 dma->enable_bit = UARTDM_DMEN_RX_BAM_ENABLE;
374
375 return;
376 err:
377 kfree(dma->virt);
378 rel_rx:
379 dma_release_channel(dma->chan);
380 no_rx:
381 memset(dma, 0, sizeof(*dma));
382 }
383
384 static inline void msm_wait_for_xmitr(struct uart_port *port)
385 {
386 unsigned int timeout = 500000;
387
388 while (!(msm_read(port, UART_SR) & UART_SR_TX_EMPTY)) {
389 if (msm_read(port, UART_ISR) & UART_ISR_TX_READY)
390 break;
391 udelay(1);
392 if (!timeout--)
393 break;
394 }
395 msm_write(port, UART_CR_CMD_RESET_TX_READY, UART_CR);
396 }
397
398 static void msm_stop_tx(struct uart_port *port)
399 {
400 struct msm_port *msm_port = UART_TO_MSM(port);
401
402 msm_port->imr &= ~UART_IMR_TXLEV;
403 msm_write(port, msm_port->imr, UART_IMR);
404 }
405
406 static void msm_start_tx(struct uart_port *port)
407 {
408 struct msm_port *msm_port = UART_TO_MSM(port);
409 struct msm_dma *dma = &msm_port->tx_dma;
410
411 /* Already started in DMA mode */
412 if (dma->count)
413 return;
414
415 msm_port->imr |= UART_IMR_TXLEV;
416 msm_write(port, msm_port->imr, UART_IMR);
417 }
418
419 static void msm_reset_dm_count(struct uart_port *port, int count)
420 {
421 msm_wait_for_xmitr(port);
422 msm_write(port, count, UARTDM_NCF_TX);
423 msm_read(port, UARTDM_NCF_TX);
424 }
425
426 static void msm_complete_tx_dma(void *args)
427 {
428 struct msm_port *msm_port = args;
429 struct uart_port *port = &msm_port->uart;
430 struct circ_buf *xmit = &port->state->xmit;
431 struct msm_dma *dma = &msm_port->tx_dma;
432 struct dma_tx_state state;
433 enum dma_status status;
434 unsigned long flags;
435 unsigned int count;
436 u32 val;
437
438 spin_lock_irqsave(&port->lock, flags);
439
440 /* Already stopped */
441 if (!dma->count)
442 goto done;
443
444 status = dmaengine_tx_status(dma->chan, dma->cookie, &state);
445
446 dma_unmap_single(port->dev, dma->phys, dma->count, dma->dir);
447
448 val = msm_read(port, UARTDM_DMEN);
449 val &= ~dma->enable_bit;
450 msm_write(port, val, UARTDM_DMEN);
451
452 if (msm_port->is_uartdm > UARTDM_1P3) {
453 msm_write(port, UART_CR_CMD_RESET_TX, UART_CR);
454 msm_write(port, UART_CR_TX_ENABLE, UART_CR);
455 }
456
457 count = dma->count - state.residue;
458 port->icount.tx += count;
459 dma->count = 0;
460
461 xmit->tail += count;
462 xmit->tail &= UART_XMIT_SIZE - 1;
463
464 /* Restore "Tx FIFO below watermark" interrupt */
465 msm_port->imr |= UART_IMR_TXLEV;
466 msm_write(port, msm_port->imr, UART_IMR);
467
468 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
469 uart_write_wakeup(port);
470
471 msm_handle_tx(port);
472 done:
473 spin_unlock_irqrestore(&port->lock, flags);
474 }
475
476 static int msm_handle_tx_dma(struct msm_port *msm_port, unsigned int count)
477 {
478 struct circ_buf *xmit = &msm_port->uart.state->xmit;
479 struct uart_port *port = &msm_port->uart;
480 struct msm_dma *dma = &msm_port->tx_dma;
481 void *cpu_addr;
482 int ret;
483 u32 val;
484
485 cpu_addr = &xmit->buf[xmit->tail];
486
487 dma->phys = dma_map_single(port->dev, cpu_addr, count, dma->dir);
488 ret = dma_mapping_error(port->dev, dma->phys);
489 if (ret)
490 return ret;
491
492 dma->desc = dmaengine_prep_slave_single(dma->chan, dma->phys,
493 count, DMA_MEM_TO_DEV,
494 DMA_PREP_INTERRUPT |
495 DMA_PREP_FENCE);
496 if (!dma->desc) {
497 ret = -EIO;
498 goto unmap;
499 }
500
501 dma->desc->callback = msm_complete_tx_dma;
502 dma->desc->callback_param = msm_port;
503
504 dma->cookie = dmaengine_submit(dma->desc);
505 ret = dma_submit_error(dma->cookie);
506 if (ret)
507 goto unmap;
508
509 /*
510 * Using DMA complete for Tx FIFO reload, no need for
511 * "Tx FIFO below watermark" one, disable it
512 */
513 msm_port->imr &= ~UART_IMR_TXLEV;
514 msm_write(port, msm_port->imr, UART_IMR);
515
516 dma->count = count;
517
518 val = msm_read(port, UARTDM_DMEN);
519 val |= dma->enable_bit;
520
521 if (msm_port->is_uartdm < UARTDM_1P4)
522 msm_write(port, val, UARTDM_DMEN);
523
524 msm_reset_dm_count(port, count);
525
526 if (msm_port->is_uartdm > UARTDM_1P3)
527 msm_write(port, val, UARTDM_DMEN);
528
529 dma_async_issue_pending(dma->chan);
530 return 0;
531 unmap:
532 dma_unmap_single(port->dev, dma->phys, count, dma->dir);
533 return ret;
534 }
535
536 static void msm_complete_rx_dma(void *args)
537 {
538 struct msm_port *msm_port = args;
539 struct uart_port *port = &msm_port->uart;
540 struct tty_port *tport = &port->state->port;
541 struct msm_dma *dma = &msm_port->rx_dma;
542 int count = 0, i, sysrq;
543 unsigned long flags;
544 u32 val;
545
546 spin_lock_irqsave(&port->lock, flags);
547
548 /* Already stopped */
549 if (!dma->count)
550 goto done;
551
552 val = msm_read(port, UARTDM_DMEN);
553 val &= ~dma->enable_bit;
554 msm_write(port, val, UARTDM_DMEN);
555
556 if (msm_read(port, UART_SR) & UART_SR_OVERRUN) {
557 port->icount.overrun++;
558 tty_insert_flip_char(tport, 0, TTY_OVERRUN);
559 msm_write(port, UART_CR_CMD_RESET_ERR, UART_CR);
560 }
561
562 count = msm_read(port, UARTDM_RX_TOTAL_SNAP);
563
564 port->icount.rx += count;
565
566 dma->count = 0;
567
568 dma_unmap_single(port->dev, dma->phys, UARTDM_RX_SIZE, dma->dir);
569
570 for (i = 0; i < count; i++) {
571 char flag = TTY_NORMAL;
572
573 if (msm_port->break_detected && dma->virt[i] == 0) {
574 port->icount.brk++;
575 flag = TTY_BREAK;
576 msm_port->break_detected = false;
577 if (uart_handle_break(port))
578 continue;
579 }
580
581 if (!(port->read_status_mask & UART_SR_RX_BREAK))
582 flag = TTY_NORMAL;
583
584 spin_unlock_irqrestore(&port->lock, flags);
585 sysrq = uart_handle_sysrq_char(port, dma->virt[i]);
586 spin_lock_irqsave(&port->lock, flags);
587 if (!sysrq)
588 tty_insert_flip_char(tport, dma->virt[i], flag);
589 }
590
591 msm_start_rx_dma(msm_port);
592 done:
593 spin_unlock_irqrestore(&port->lock, flags);
594
595 if (count)
596 tty_flip_buffer_push(tport);
597 }
598
599 static void msm_start_rx_dma(struct msm_port *msm_port)
600 {
601 struct msm_dma *dma = &msm_port->rx_dma;
602 struct uart_port *uart = &msm_port->uart;
603 u32 val;
604 int ret;
605
606 if (!dma->chan)
607 return;
608
609 dma->phys = dma_map_single(uart->dev, dma->virt,
610 UARTDM_RX_SIZE, dma->dir);
611 ret = dma_mapping_error(uart->dev, dma->phys);
612 if (ret)
613 return;
614
615 dma->desc = dmaengine_prep_slave_single(dma->chan, dma->phys,
616 UARTDM_RX_SIZE, DMA_DEV_TO_MEM,
617 DMA_PREP_INTERRUPT);
618 if (!dma->desc)
619 goto unmap;
620
621 dma->desc->callback = msm_complete_rx_dma;
622 dma->desc->callback_param = msm_port;
623
624 dma->cookie = dmaengine_submit(dma->desc);
625 ret = dma_submit_error(dma->cookie);
626 if (ret)
627 goto unmap;
628 /*
629 * Using DMA for FIFO off-load, no need for "Rx FIFO over
630 * watermark" or "stale" interrupts, disable them
631 */
632 msm_port->imr &= ~(UART_IMR_RXLEV | UART_IMR_RXSTALE);
633
634 /*
635 * Well, when DMA is ADM3 engine(implied by <= UARTDM v1.3),
636 * we need RXSTALE to flush input DMA fifo to memory
637 */
638 if (msm_port->is_uartdm < UARTDM_1P4)
639 msm_port->imr |= UART_IMR_RXSTALE;
640
641 msm_write(uart, msm_port->imr, UART_IMR);
642
643 dma->count = UARTDM_RX_SIZE;
644
645 dma_async_issue_pending(dma->chan);
646
647 msm_write(uart, UART_CR_CMD_RESET_STALE_INT, UART_CR);
648 msm_write(uart, UART_CR_CMD_STALE_EVENT_ENABLE, UART_CR);
649
650 val = msm_read(uart, UARTDM_DMEN);
651 val |= dma->enable_bit;
652
653 if (msm_port->is_uartdm < UARTDM_1P4)
654 msm_write(uart, val, UARTDM_DMEN);
655
656 msm_write(uart, UARTDM_RX_SIZE, UARTDM_DMRX);
657
658 if (msm_port->is_uartdm > UARTDM_1P3)
659 msm_write(uart, val, UARTDM_DMEN);
660
661 return;
662 unmap:
663 dma_unmap_single(uart->dev, dma->phys, UARTDM_RX_SIZE, dma->dir);
664 }
665
666 static void msm_stop_rx(struct uart_port *port)
667 {
668 struct msm_port *msm_port = UART_TO_MSM(port);
669 struct msm_dma *dma = &msm_port->rx_dma;
670
671 msm_port->imr &= ~(UART_IMR_RXLEV | UART_IMR_RXSTALE);
672 msm_write(port, msm_port->imr, UART_IMR);
673
674 if (dma->chan)
675 msm_stop_dma(port, dma);
676 }
677
678 static void msm_enable_ms(struct uart_port *port)
679 {
680 struct msm_port *msm_port = UART_TO_MSM(port);
681
682 msm_port->imr |= UART_IMR_DELTA_CTS;
683 msm_write(port, msm_port->imr, UART_IMR);
684 }
685
686 static void msm_handle_rx_dm(struct uart_port *port, unsigned int misr)
687 {
688 struct tty_port *tport = &port->state->port;
689 unsigned int sr;
690 int count = 0;
691 struct msm_port *msm_port = UART_TO_MSM(port);
692
693 if ((msm_read(port, UART_SR) & UART_SR_OVERRUN)) {
694 port->icount.overrun++;
695 tty_insert_flip_char(tport, 0, TTY_OVERRUN);
696 msm_write(port, UART_CR_CMD_RESET_ERR, UART_CR);
697 }
698
699 if (misr & UART_IMR_RXSTALE) {
700 count = msm_read(port, UARTDM_RX_TOTAL_SNAP) -
701 msm_port->old_snap_state;
702 msm_port->old_snap_state = 0;
703 } else {
704 count = 4 * (msm_read(port, UART_RFWR));
705 msm_port->old_snap_state += count;
706 }
707
708 /* TODO: Precise error reporting */
709
710 port->icount.rx += count;
711
712 while (count > 0) {
713 unsigned char buf[4];
714 int sysrq, r_count, i;
715
716 sr = msm_read(port, UART_SR);
717 if ((sr & UART_SR_RX_READY) == 0) {
718 msm_port->old_snap_state -= count;
719 break;
720 }
721
722 ioread32_rep(port->membase + UARTDM_RF, buf, 1);
723 r_count = min_t(int, count, sizeof(buf));
724
725 for (i = 0; i < r_count; i++) {
726 char flag = TTY_NORMAL;
727
728 if (msm_port->break_detected && buf[i] == 0) {
729 port->icount.brk++;
730 flag = TTY_BREAK;
731 msm_port->break_detected = false;
732 if (uart_handle_break(port))
733 continue;
734 }
735
736 if (!(port->read_status_mask & UART_SR_RX_BREAK))
737 flag = TTY_NORMAL;
738
739 spin_unlock(&port->lock);
740 sysrq = uart_handle_sysrq_char(port, buf[i]);
741 spin_lock(&port->lock);
742 if (!sysrq)
743 tty_insert_flip_char(tport, buf[i], flag);
744 }
745 count -= r_count;
746 }
747
748 spin_unlock(&port->lock);
749 tty_flip_buffer_push(tport);
750 spin_lock(&port->lock);
751
752 if (misr & (UART_IMR_RXSTALE))
753 msm_write(port, UART_CR_CMD_RESET_STALE_INT, UART_CR);
754 msm_write(port, 0xFFFFFF, UARTDM_DMRX);
755 msm_write(port, UART_CR_CMD_STALE_EVENT_ENABLE, UART_CR);
756
757 /* Try to use DMA */
758 msm_start_rx_dma(msm_port);
759 }
760
761 static void msm_handle_rx(struct uart_port *port)
762 {
763 struct tty_port *tport = &port->state->port;
764 unsigned int sr;
765
766 /*
767 * Handle overrun. My understanding of the hardware is that overrun
768 * is not tied to the RX buffer, so we handle the case out of band.
769 */
770 if ((msm_read(port, UART_SR) & UART_SR_OVERRUN)) {
771 port->icount.overrun++;
772 tty_insert_flip_char(tport, 0, TTY_OVERRUN);
773 msm_write(port, UART_CR_CMD_RESET_ERR, UART_CR);
774 }
775
776 /* and now the main RX loop */
777 while ((sr = msm_read(port, UART_SR)) & UART_SR_RX_READY) {
778 unsigned int c;
779 char flag = TTY_NORMAL;
780 int sysrq;
781
782 c = msm_read(port, UART_RF);
783
784 if (sr & UART_SR_RX_BREAK) {
785 port->icount.brk++;
786 if (uart_handle_break(port))
787 continue;
788 } else if (sr & UART_SR_PAR_FRAME_ERR) {
789 port->icount.frame++;
790 } else {
791 port->icount.rx++;
792 }
793
794 /* Mask conditions we're ignorning. */
795 sr &= port->read_status_mask;
796
797 if (sr & UART_SR_RX_BREAK)
798 flag = TTY_BREAK;
799 else if (sr & UART_SR_PAR_FRAME_ERR)
800 flag = TTY_FRAME;
801
802 spin_unlock(&port->lock);
803 sysrq = uart_handle_sysrq_char(port, c);
804 spin_lock(&port->lock);
805 if (!sysrq)
806 tty_insert_flip_char(tport, c, flag);
807 }
808
809 spin_unlock(&port->lock);
810 tty_flip_buffer_push(tport);
811 spin_lock(&port->lock);
812 }
813
814 static void msm_handle_tx_pio(struct uart_port *port, unsigned int tx_count)
815 {
816 struct circ_buf *xmit = &port->state->xmit;
817 struct msm_port *msm_port = UART_TO_MSM(port);
818 unsigned int num_chars;
819 unsigned int tf_pointer = 0;
820 void __iomem *tf;
821
822 if (msm_port->is_uartdm)
823 tf = port->membase + UARTDM_TF;
824 else
825 tf = port->membase + UART_TF;
826
827 if (tx_count && msm_port->is_uartdm)
828 msm_reset_dm_count(port, tx_count);
829
830 while (tf_pointer < tx_count) {
831 int i;
832 char buf[4] = { 0 };
833
834 if (!(msm_read(port, UART_SR) & UART_SR_TX_READY))
835 break;
836
837 if (msm_port->is_uartdm)
838 num_chars = min(tx_count - tf_pointer,
839 (unsigned int)sizeof(buf));
840 else
841 num_chars = 1;
842
843 for (i = 0; i < num_chars; i++) {
844 buf[i] = xmit->buf[xmit->tail + i];
845 port->icount.tx++;
846 }
847
848 iowrite32_rep(tf, buf, 1);
849 xmit->tail = (xmit->tail + num_chars) & (UART_XMIT_SIZE - 1);
850 tf_pointer += num_chars;
851 }
852
853 /* disable tx interrupts if nothing more to send */
854 if (uart_circ_empty(xmit))
855 msm_stop_tx(port);
856
857 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
858 uart_write_wakeup(port);
859 }
860
861 static void msm_handle_tx(struct uart_port *port)
862 {
863 struct msm_port *msm_port = UART_TO_MSM(port);
864 struct circ_buf *xmit = &msm_port->uart.state->xmit;
865 struct msm_dma *dma = &msm_port->tx_dma;
866 unsigned int pio_count, dma_count, dma_min;
867 char buf[4] = { 0 };
868 void __iomem *tf;
869 int err = 0;
870
871 if (port->x_char) {
872 if (msm_port->is_uartdm)
873 tf = port->membase + UARTDM_TF;
874 else
875 tf = port->membase + UART_TF;
876
877 buf[0] = port->x_char;
878
879 if (msm_port->is_uartdm)
880 msm_reset_dm_count(port, 1);
881
882 iowrite32_rep(tf, buf, 1);
883 port->icount.tx++;
884 port->x_char = 0;
885 return;
886 }
887
888 if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
889 msm_stop_tx(port);
890 return;
891 }
892
893 pio_count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
894 dma_count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
895
896 dma_min = 1; /* Always DMA */
897 if (msm_port->is_uartdm > UARTDM_1P3) {
898 dma_count = UARTDM_TX_AIGN(dma_count);
899 dma_min = UARTDM_BURST_SIZE;
900 } else {
901 if (dma_count > UARTDM_TX_MAX)
902 dma_count = UARTDM_TX_MAX;
903 }
904
905 if (pio_count > port->fifosize)
906 pio_count = port->fifosize;
907
908 if (!dma->chan || dma_count < dma_min)
909 msm_handle_tx_pio(port, pio_count);
910 else
911 err = msm_handle_tx_dma(msm_port, dma_count);
912
913 if (err) /* fall back to PIO mode */
914 msm_handle_tx_pio(port, pio_count);
915 }
916
917 static void msm_handle_delta_cts(struct uart_port *port)
918 {
919 msm_write(port, UART_CR_CMD_RESET_CTS, UART_CR);
920 port->icount.cts++;
921 wake_up_interruptible(&port->state->port.delta_msr_wait);
922 }
923
924 static irqreturn_t msm_uart_irq(int irq, void *dev_id)
925 {
926 struct uart_port *port = dev_id;
927 struct msm_port *msm_port = UART_TO_MSM(port);
928 struct msm_dma *dma = &msm_port->rx_dma;
929 unsigned long flags;
930 unsigned int misr;
931 u32 val;
932
933 spin_lock_irqsave(&port->lock, flags);
934 misr = msm_read(port, UART_MISR);
935 msm_write(port, 0, UART_IMR); /* disable interrupt */
936
937 if (misr & UART_IMR_RXBREAK_START) {
938 msm_port->break_detected = true;
939 msm_write(port, UART_CR_CMD_RESET_RXBREAK_START, UART_CR);
940 }
941
942 if (misr & (UART_IMR_RXLEV | UART_IMR_RXSTALE)) {
943 if (dma->count) {
944 val = UART_CR_CMD_STALE_EVENT_DISABLE;
945 msm_write(port, val, UART_CR);
946 val = UART_CR_CMD_RESET_STALE_INT;
947 msm_write(port, val, UART_CR);
948 /*
949 * Flush DMA input fifo to memory, this will also
950 * trigger DMA RX completion
951 */
952 dmaengine_terminate_all(dma->chan);
953 } else if (msm_port->is_uartdm) {
954 msm_handle_rx_dm(port, misr);
955 } else {
956 msm_handle_rx(port);
957 }
958 }
959 if (misr & UART_IMR_TXLEV)
960 msm_handle_tx(port);
961 if (misr & UART_IMR_DELTA_CTS)
962 msm_handle_delta_cts(port);
963
964 msm_write(port, msm_port->imr, UART_IMR); /* restore interrupt */
965 spin_unlock_irqrestore(&port->lock, flags);
966
967 return IRQ_HANDLED;
968 }
969
970 static unsigned int msm_tx_empty(struct uart_port *port)
971 {
972 return (msm_read(port, UART_SR) & UART_SR_TX_EMPTY) ? TIOCSER_TEMT : 0;
973 }
974
975 static unsigned int msm_get_mctrl(struct uart_port *port)
976 {
977 return TIOCM_CAR | TIOCM_CTS | TIOCM_DSR | TIOCM_RTS;
978 }
979
980 static void msm_reset(struct uart_port *port)
981 {
982 struct msm_port *msm_port = UART_TO_MSM(port);
983 unsigned int mr;
984
985 /* reset everything */
986 msm_write(port, UART_CR_CMD_RESET_RX, UART_CR);
987 msm_write(port, UART_CR_CMD_RESET_TX, UART_CR);
988 msm_write(port, UART_CR_CMD_RESET_ERR, UART_CR);
989 msm_write(port, UART_CR_CMD_RESET_BREAK_INT, UART_CR);
990 msm_write(port, UART_CR_CMD_RESET_CTS, UART_CR);
991 msm_write(port, UART_CR_CMD_RESET_RFR, UART_CR);
992 mr = msm_read(port, UART_MR1);
993 mr &= ~UART_MR1_RX_RDY_CTL;
994 msm_write(port, mr, UART_MR1);
995
996 /* Disable DM modes */
997 if (msm_port->is_uartdm)
998 msm_write(port, 0, UARTDM_DMEN);
999 }
1000
1001 static void msm_set_mctrl(struct uart_port *port, unsigned int mctrl)
1002 {
1003 unsigned int mr;
1004
1005 mr = msm_read(port, UART_MR1);
1006
1007 if (!(mctrl & TIOCM_RTS)) {
1008 mr &= ~UART_MR1_RX_RDY_CTL;
1009 msm_write(port, mr, UART_MR1);
1010 msm_write(port, UART_CR_CMD_RESET_RFR, UART_CR);
1011 } else {
1012 mr |= UART_MR1_RX_RDY_CTL;
1013 msm_write(port, mr, UART_MR1);
1014 }
1015 }
1016
1017 static void msm_break_ctl(struct uart_port *port, int break_ctl)
1018 {
1019 if (break_ctl)
1020 msm_write(port, UART_CR_CMD_START_BREAK, UART_CR);
1021 else
1022 msm_write(port, UART_CR_CMD_STOP_BREAK, UART_CR);
1023 }
1024
1025 struct msm_baud_map {
1026 u16 divisor;
1027 u8 code;
1028 u8 rxstale;
1029 };
1030
1031 static const struct msm_baud_map *
1032 msm_find_best_baud(struct uart_port *port, unsigned int baud,
1033 unsigned long *rate)
1034 {
1035 struct msm_port *msm_port = UART_TO_MSM(port);
1036 unsigned int divisor, result;
1037 unsigned long target, old, best_rate = 0, diff, best_diff = ULONG_MAX;
1038 const struct msm_baud_map *entry, *end, *best;
1039 static const struct msm_baud_map table[] = {
1040 { 1, 0xff, 31 },
1041 { 2, 0xee, 16 },
1042 { 3, 0xdd, 8 },
1043 { 4, 0xcc, 6 },
1044 { 6, 0xbb, 6 },
1045 { 8, 0xaa, 6 },
1046 { 12, 0x99, 6 },
1047 { 16, 0x88, 1 },
1048 { 24, 0x77, 1 },
1049 { 32, 0x66, 1 },
1050 { 48, 0x55, 1 },
1051 { 96, 0x44, 1 },
1052 { 192, 0x33, 1 },
1053 { 384, 0x22, 1 },
1054 { 768, 0x11, 1 },
1055 { 1536, 0x00, 1 },
1056 };
1057
1058 best = table; /* Default to smallest divider */
1059 target = clk_round_rate(msm_port->clk, 16 * baud);
1060 divisor = DIV_ROUND_CLOSEST(target, 16 * baud);
1061
1062 end = table + ARRAY_SIZE(table);
1063 entry = table;
1064 while (entry < end) {
1065 if (entry->divisor <= divisor) {
1066 result = target / entry->divisor / 16;
1067 diff = abs(result - baud);
1068
1069 /* Keep track of best entry */
1070 if (diff < best_diff) {
1071 best_diff = diff;
1072 best = entry;
1073 best_rate = target;
1074 }
1075
1076 if (result == baud)
1077 break;
1078 } else if (entry->divisor > divisor) {
1079 old = target;
1080 target = clk_round_rate(msm_port->clk, old + 1);
1081 /*
1082 * The rate didn't get any faster so we can't do
1083 * better at dividing it down
1084 */
1085 if (target == old)
1086 break;
1087
1088 /* Start the divisor search over at this new rate */
1089 entry = table;
1090 divisor = DIV_ROUND_CLOSEST(target, 16 * baud);
1091 continue;
1092 }
1093 entry++;
1094 }
1095
1096 *rate = best_rate;
1097 return best;
1098 }
1099
1100 static int msm_set_baud_rate(struct uart_port *port, unsigned int baud,
1101 unsigned long *saved_flags)
1102 {
1103 unsigned int rxstale, watermark, mask;
1104 struct msm_port *msm_port = UART_TO_MSM(port);
1105 const struct msm_baud_map *entry;
1106 unsigned long flags, rate;
1107
1108 flags = *saved_flags;
1109 spin_unlock_irqrestore(&port->lock, flags);
1110
1111 entry = msm_find_best_baud(port, baud, &rate);
1112 clk_set_rate(msm_port->clk, rate);
1113 baud = rate / 16 / entry->divisor;
1114
1115 spin_lock_irqsave(&port->lock, flags);
1116 *saved_flags = flags;
1117 port->uartclk = rate;
1118
1119 msm_write(port, entry->code, UART_CSR);
1120
1121 /* RX stale watermark */
1122 rxstale = entry->rxstale;
1123 watermark = UART_IPR_STALE_LSB & rxstale;
1124 if (msm_port->is_uartdm) {
1125 mask = UART_DM_IPR_STALE_TIMEOUT_MSB;
1126 } else {
1127 watermark |= UART_IPR_RXSTALE_LAST;
1128 mask = UART_IPR_STALE_TIMEOUT_MSB;
1129 }
1130
1131 watermark |= mask & (rxstale << 2);
1132
1133 msm_write(port, watermark, UART_IPR);
1134
1135 /* set RX watermark */
1136 watermark = (port->fifosize * 3) / 4;
1137 msm_write(port, watermark, UART_RFWR);
1138
1139 /* set TX watermark */
1140 msm_write(port, 10, UART_TFWR);
1141
1142 msm_write(port, UART_CR_CMD_PROTECTION_EN, UART_CR);
1143 msm_reset(port);
1144
1145 /* Enable RX and TX */
1146 msm_write(port, UART_CR_TX_ENABLE | UART_CR_RX_ENABLE, UART_CR);
1147
1148 /* turn on RX and CTS interrupts */
1149 msm_port->imr = UART_IMR_RXLEV | UART_IMR_RXSTALE |
1150 UART_IMR_CURRENT_CTS | UART_IMR_RXBREAK_START;
1151
1152 msm_write(port, msm_port->imr, UART_IMR);
1153
1154 if (msm_port->is_uartdm) {
1155 msm_write(port, UART_CR_CMD_RESET_STALE_INT, UART_CR);
1156 msm_write(port, 0xFFFFFF, UARTDM_DMRX);
1157 msm_write(port, UART_CR_CMD_STALE_EVENT_ENABLE, UART_CR);
1158 }
1159
1160 return baud;
1161 }
1162
1163 static void msm_init_clock(struct uart_port *port)
1164 {
1165 struct msm_port *msm_port = UART_TO_MSM(port);
1166
1167 clk_prepare_enable(msm_port->clk);
1168 clk_prepare_enable(msm_port->pclk);
1169 msm_serial_set_mnd_regs(port);
1170 }
1171
1172 static int msm_startup(struct uart_port *port)
1173 {
1174 struct msm_port *msm_port = UART_TO_MSM(port);
1175 unsigned int data, rfr_level, mask;
1176 int ret;
1177
1178 snprintf(msm_port->name, sizeof(msm_port->name),
1179 "msm_serial%d", port->line);
1180
1181 msm_init_clock(port);
1182
1183 if (likely(port->fifosize > 12))
1184 rfr_level = port->fifosize - 12;
1185 else
1186 rfr_level = port->fifosize;
1187
1188 /* set automatic RFR level */
1189 data = msm_read(port, UART_MR1);
1190
1191 if (msm_port->is_uartdm)
1192 mask = UART_DM_MR1_AUTO_RFR_LEVEL1;
1193 else
1194 mask = UART_MR1_AUTO_RFR_LEVEL1;
1195
1196 data &= ~mask;
1197 data &= ~UART_MR1_AUTO_RFR_LEVEL0;
1198 data |= mask & (rfr_level << 2);
1199 data |= UART_MR1_AUTO_RFR_LEVEL0 & rfr_level;
1200 msm_write(port, data, UART_MR1);
1201
1202 if (msm_port->is_uartdm) {
1203 msm_request_tx_dma(msm_port, msm_port->uart.mapbase);
1204 msm_request_rx_dma(msm_port, msm_port->uart.mapbase);
1205 }
1206
1207 ret = request_irq(port->irq, msm_uart_irq, IRQF_TRIGGER_HIGH,
1208 msm_port->name, port);
1209 if (unlikely(ret))
1210 goto err_irq;
1211
1212 return 0;
1213
1214 err_irq:
1215 if (msm_port->is_uartdm)
1216 msm_release_dma(msm_port);
1217
1218 clk_disable_unprepare(msm_port->pclk);
1219 clk_disable_unprepare(msm_port->clk);
1220
1221 return ret;
1222 }
1223
1224 static void msm_shutdown(struct uart_port *port)
1225 {
1226 struct msm_port *msm_port = UART_TO_MSM(port);
1227
1228 msm_port->imr = 0;
1229 msm_write(port, 0, UART_IMR); /* disable interrupts */
1230
1231 if (msm_port->is_uartdm)
1232 msm_release_dma(msm_port);
1233
1234 clk_disable_unprepare(msm_port->clk);
1235
1236 free_irq(port->irq, port);
1237 }
1238
1239 static void msm_set_termios(struct uart_port *port, struct ktermios *termios,
1240 struct ktermios *old)
1241 {
1242 struct msm_port *msm_port = UART_TO_MSM(port);
1243 struct msm_dma *dma = &msm_port->rx_dma;
1244 unsigned long flags;
1245 unsigned int baud, mr;
1246
1247 spin_lock_irqsave(&port->lock, flags);
1248
1249 if (dma->chan) /* Terminate if any */
1250 msm_stop_dma(port, dma);
1251
1252 /* calculate and set baud rate */
1253 baud = uart_get_baud_rate(port, termios, old, 300, 4000000);
1254 baud = msm_set_baud_rate(port, baud, &flags);
1255 if (tty_termios_baud_rate(termios))
1256 tty_termios_encode_baud_rate(termios, baud, baud);
1257
1258 /* calculate parity */
1259 mr = msm_read(port, UART_MR2);
1260 mr &= ~UART_MR2_PARITY_MODE;
1261 if (termios->c_cflag & PARENB) {
1262 if (termios->c_cflag & PARODD)
1263 mr |= UART_MR2_PARITY_MODE_ODD;
1264 else if (termios->c_cflag & CMSPAR)
1265 mr |= UART_MR2_PARITY_MODE_SPACE;
1266 else
1267 mr |= UART_MR2_PARITY_MODE_EVEN;
1268 }
1269
1270 /* calculate bits per char */
1271 mr &= ~UART_MR2_BITS_PER_CHAR;
1272 switch (termios->c_cflag & CSIZE) {
1273 case CS5:
1274 mr |= UART_MR2_BITS_PER_CHAR_5;
1275 break;
1276 case CS6:
1277 mr |= UART_MR2_BITS_PER_CHAR_6;
1278 break;
1279 case CS7:
1280 mr |= UART_MR2_BITS_PER_CHAR_7;
1281 break;
1282 case CS8:
1283 default:
1284 mr |= UART_MR2_BITS_PER_CHAR_8;
1285 break;
1286 }
1287
1288 /* calculate stop bits */
1289 mr &= ~(UART_MR2_STOP_BIT_LEN_ONE | UART_MR2_STOP_BIT_LEN_TWO);
1290 if (termios->c_cflag & CSTOPB)
1291 mr |= UART_MR2_STOP_BIT_LEN_TWO;
1292 else
1293 mr |= UART_MR2_STOP_BIT_LEN_ONE;
1294
1295 /* set parity, bits per char, and stop bit */
1296 msm_write(port, mr, UART_MR2);
1297
1298 /* calculate and set hardware flow control */
1299 mr = msm_read(port, UART_MR1);
1300 mr &= ~(UART_MR1_CTS_CTL | UART_MR1_RX_RDY_CTL);
1301 if (termios->c_cflag & CRTSCTS) {
1302 mr |= UART_MR1_CTS_CTL;
1303 mr |= UART_MR1_RX_RDY_CTL;
1304 }
1305 msm_write(port, mr, UART_MR1);
1306
1307 /* Configure status bits to ignore based on termio flags. */
1308 port->read_status_mask = 0;
1309 if (termios->c_iflag & INPCK)
1310 port->read_status_mask |= UART_SR_PAR_FRAME_ERR;
1311 if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
1312 port->read_status_mask |= UART_SR_RX_BREAK;
1313
1314 uart_update_timeout(port, termios->c_cflag, baud);
1315
1316 /* Try to use DMA */
1317 msm_start_rx_dma(msm_port);
1318
1319 spin_unlock_irqrestore(&port->lock, flags);
1320 }
1321
1322 static const char *msm_type(struct uart_port *port)
1323 {
1324 return "MSM";
1325 }
1326
1327 static void msm_release_port(struct uart_port *port)
1328 {
1329 struct platform_device *pdev = to_platform_device(port->dev);
1330 struct resource *uart_resource;
1331 resource_size_t size;
1332
1333 uart_resource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1334 if (unlikely(!uart_resource))
1335 return;
1336 size = resource_size(uart_resource);
1337
1338 release_mem_region(port->mapbase, size);
1339 iounmap(port->membase);
1340 port->membase = NULL;
1341 }
1342
1343 static int msm_request_port(struct uart_port *port)
1344 {
1345 struct platform_device *pdev = to_platform_device(port->dev);
1346 struct resource *uart_resource;
1347 resource_size_t size;
1348 int ret;
1349
1350 uart_resource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1351 if (unlikely(!uart_resource))
1352 return -ENXIO;
1353
1354 size = resource_size(uart_resource);
1355
1356 if (!request_mem_region(port->mapbase, size, "msm_serial"))
1357 return -EBUSY;
1358
1359 port->membase = ioremap(port->mapbase, size);
1360 if (!port->membase) {
1361 ret = -EBUSY;
1362 goto fail_release_port;
1363 }
1364
1365 return 0;
1366
1367 fail_release_port:
1368 release_mem_region(port->mapbase, size);
1369 return ret;
1370 }
1371
1372 static void msm_config_port(struct uart_port *port, int flags)
1373 {
1374 int ret;
1375
1376 if (flags & UART_CONFIG_TYPE) {
1377 port->type = PORT_MSM;
1378 ret = msm_request_port(port);
1379 if (ret)
1380 return;
1381 }
1382 }
1383
1384 static int msm_verify_port(struct uart_port *port, struct serial_struct *ser)
1385 {
1386 if (unlikely(ser->type != PORT_UNKNOWN && ser->type != PORT_MSM))
1387 return -EINVAL;
1388 if (unlikely(port->irq != ser->irq))
1389 return -EINVAL;
1390 return 0;
1391 }
1392
1393 static void msm_power(struct uart_port *port, unsigned int state,
1394 unsigned int oldstate)
1395 {
1396 struct msm_port *msm_port = UART_TO_MSM(port);
1397
1398 switch (state) {
1399 case 0:
1400 clk_prepare_enable(msm_port->clk);
1401 clk_prepare_enable(msm_port->pclk);
1402 break;
1403 case 3:
1404 clk_disable_unprepare(msm_port->clk);
1405 clk_disable_unprepare(msm_port->pclk);
1406 break;
1407 default:
1408 pr_err("msm_serial: Unknown PM state %d\n", state);
1409 }
1410 }
1411
1412 #ifdef CONFIG_CONSOLE_POLL
1413 static int msm_poll_get_char_single(struct uart_port *port)
1414 {
1415 struct msm_port *msm_port = UART_TO_MSM(port);
1416 unsigned int rf_reg = msm_port->is_uartdm ? UARTDM_RF : UART_RF;
1417
1418 if (!(msm_read(port, UART_SR) & UART_SR_RX_READY))
1419 return NO_POLL_CHAR;
1420
1421 return msm_read(port, rf_reg) & 0xff;
1422 }
1423
1424 static int msm_poll_get_char_dm(struct uart_port *port)
1425 {
1426 int c;
1427 static u32 slop;
1428 static int count;
1429 unsigned char *sp = (unsigned char *)&slop;
1430
1431 /* Check if a previous read had more than one char */
1432 if (count) {
1433 c = sp[sizeof(slop) - count];
1434 count--;
1435 /* Or if FIFO is empty */
1436 } else if (!(msm_read(port, UART_SR) & UART_SR_RX_READY)) {
1437 /*
1438 * If RX packing buffer has less than a word, force stale to
1439 * push contents into RX FIFO
1440 */
1441 count = msm_read(port, UARTDM_RXFS);
1442 count = (count >> UARTDM_RXFS_BUF_SHIFT) & UARTDM_RXFS_BUF_MASK;
1443 if (count) {
1444 msm_write(port, UART_CR_CMD_FORCE_STALE, UART_CR);
1445 slop = msm_read(port, UARTDM_RF);
1446 c = sp[0];
1447 count--;
1448 msm_write(port, UART_CR_CMD_RESET_STALE_INT, UART_CR);
1449 msm_write(port, 0xFFFFFF, UARTDM_DMRX);
1450 msm_write(port, UART_CR_CMD_STALE_EVENT_ENABLE,
1451 UART_CR);
1452 } else {
1453 c = NO_POLL_CHAR;
1454 }
1455 /* FIFO has a word */
1456 } else {
1457 slop = msm_read(port, UARTDM_RF);
1458 c = sp[0];
1459 count = sizeof(slop) - 1;
1460 }
1461
1462 return c;
1463 }
1464
1465 static int msm_poll_get_char(struct uart_port *port)
1466 {
1467 u32 imr;
1468 int c;
1469 struct msm_port *msm_port = UART_TO_MSM(port);
1470
1471 /* Disable all interrupts */
1472 imr = msm_read(port, UART_IMR);
1473 msm_write(port, 0, UART_IMR);
1474
1475 if (msm_port->is_uartdm)
1476 c = msm_poll_get_char_dm(port);
1477 else
1478 c = msm_poll_get_char_single(port);
1479
1480 /* Enable interrupts */
1481 msm_write(port, imr, UART_IMR);
1482
1483 return c;
1484 }
1485
1486 static void msm_poll_put_char(struct uart_port *port, unsigned char c)
1487 {
1488 u32 imr;
1489 struct msm_port *msm_port = UART_TO_MSM(port);
1490
1491 /* Disable all interrupts */
1492 imr = msm_read(port, UART_IMR);
1493 msm_write(port, 0, UART_IMR);
1494
1495 if (msm_port->is_uartdm)
1496 msm_reset_dm_count(port, 1);
1497
1498 /* Wait until FIFO is empty */
1499 while (!(msm_read(port, UART_SR) & UART_SR_TX_READY))
1500 cpu_relax();
1501
1502 /* Write a character */
1503 msm_write(port, c, msm_port->is_uartdm ? UARTDM_TF : UART_TF);
1504
1505 /* Wait until FIFO is empty */
1506 while (!(msm_read(port, UART_SR) & UART_SR_TX_READY))
1507 cpu_relax();
1508
1509 /* Enable interrupts */
1510 msm_write(port, imr, UART_IMR);
1511 }
1512 #endif
1513
1514 static struct uart_ops msm_uart_pops = {
1515 .tx_empty = msm_tx_empty,
1516 .set_mctrl = msm_set_mctrl,
1517 .get_mctrl = msm_get_mctrl,
1518 .stop_tx = msm_stop_tx,
1519 .start_tx = msm_start_tx,
1520 .stop_rx = msm_stop_rx,
1521 .enable_ms = msm_enable_ms,
1522 .break_ctl = msm_break_ctl,
1523 .startup = msm_startup,
1524 .shutdown = msm_shutdown,
1525 .set_termios = msm_set_termios,
1526 .type = msm_type,
1527 .release_port = msm_release_port,
1528 .request_port = msm_request_port,
1529 .config_port = msm_config_port,
1530 .verify_port = msm_verify_port,
1531 .pm = msm_power,
1532 #ifdef CONFIG_CONSOLE_POLL
1533 .poll_get_char = msm_poll_get_char,
1534 .poll_put_char = msm_poll_put_char,
1535 #endif
1536 };
1537
1538 static struct msm_port msm_uart_ports[] = {
1539 {
1540 .uart = {
1541 .iotype = UPIO_MEM,
1542 .ops = &msm_uart_pops,
1543 .flags = UPF_BOOT_AUTOCONF,
1544 .fifosize = 64,
1545 .line = 0,
1546 },
1547 },
1548 {
1549 .uart = {
1550 .iotype = UPIO_MEM,
1551 .ops = &msm_uart_pops,
1552 .flags = UPF_BOOT_AUTOCONF,
1553 .fifosize = 64,
1554 .line = 1,
1555 },
1556 },
1557 {
1558 .uart = {
1559 .iotype = UPIO_MEM,
1560 .ops = &msm_uart_pops,
1561 .flags = UPF_BOOT_AUTOCONF,
1562 .fifosize = 64,
1563 .line = 2,
1564 },
1565 },
1566 };
1567
1568 #define UART_NR ARRAY_SIZE(msm_uart_ports)
1569
1570 static inline struct uart_port *msm_get_port_from_line(unsigned int line)
1571 {
1572 return &msm_uart_ports[line].uart;
1573 }
1574
1575 #ifdef CONFIG_SERIAL_MSM_CONSOLE
1576 static void __msm_console_write(struct uart_port *port, const char *s,
1577 unsigned int count, bool is_uartdm)
1578 {
1579 int i;
1580 int num_newlines = 0;
1581 bool replaced = false;
1582 void __iomem *tf;
1583 int locked = 1;
1584
1585 if (is_uartdm)
1586 tf = port->membase + UARTDM_TF;
1587 else
1588 tf = port->membase + UART_TF;
1589
1590 /* Account for newlines that will get a carriage return added */
1591 for (i = 0; i < count; i++)
1592 if (s[i] == '\n')
1593 num_newlines++;
1594 count += num_newlines;
1595
1596 if (port->sysrq)
1597 locked = 0;
1598 else if (oops_in_progress)
1599 locked = spin_trylock(&port->lock);
1600 else
1601 spin_lock(&port->lock);
1602
1603 if (is_uartdm)
1604 msm_reset_dm_count(port, count);
1605
1606 i = 0;
1607 while (i < count) {
1608 int j;
1609 unsigned int num_chars;
1610 char buf[4] = { 0 };
1611
1612 if (is_uartdm)
1613 num_chars = min(count - i, (unsigned int)sizeof(buf));
1614 else
1615 num_chars = 1;
1616
1617 for (j = 0; j < num_chars; j++) {
1618 char c = *s;
1619
1620 if (c == '\n' && !replaced) {
1621 buf[j] = '\r';
1622 j++;
1623 replaced = true;
1624 }
1625 if (j < num_chars) {
1626 buf[j] = c;
1627 s++;
1628 replaced = false;
1629 }
1630 }
1631
1632 while (!(msm_read(port, UART_SR) & UART_SR_TX_READY))
1633 cpu_relax();
1634
1635 iowrite32_rep(tf, buf, 1);
1636 i += num_chars;
1637 }
1638
1639 if (locked)
1640 spin_unlock(&port->lock);
1641 }
1642
1643 static void msm_console_write(struct console *co, const char *s,
1644 unsigned int count)
1645 {
1646 struct uart_port *port;
1647 struct msm_port *msm_port;
1648
1649 BUG_ON(co->index < 0 || co->index >= UART_NR);
1650
1651 port = msm_get_port_from_line(co->index);
1652 msm_port = UART_TO_MSM(port);
1653
1654 __msm_console_write(port, s, count, msm_port->is_uartdm);
1655 }
1656
1657 static int __init msm_console_setup(struct console *co, char *options)
1658 {
1659 struct uart_port *port;
1660 int baud = 115200;
1661 int bits = 8;
1662 int parity = 'n';
1663 int flow = 'n';
1664
1665 if (unlikely(co->index >= UART_NR || co->index < 0))
1666 return -ENXIO;
1667
1668 port = msm_get_port_from_line(co->index);
1669
1670 if (unlikely(!port->membase))
1671 return -ENXIO;
1672
1673 msm_init_clock(port);
1674
1675 if (options)
1676 uart_parse_options(options, &baud, &parity, &bits, &flow);
1677
1678 pr_info("msm_serial: console setup on port #%d\n", port->line);
1679
1680 return uart_set_options(port, co, baud, parity, bits, flow);
1681 }
1682
1683 static void
1684 msm_serial_early_write(struct console *con, const char *s, unsigned n)
1685 {
1686 struct earlycon_device *dev = con->data;
1687
1688 __msm_console_write(&dev->port, s, n, false);
1689 }
1690
1691 static int __init
1692 msm_serial_early_console_setup(struct earlycon_device *device, const char *opt)
1693 {
1694 if (!device->port.membase)
1695 return -ENODEV;
1696
1697 device->con->write = msm_serial_early_write;
1698 return 0;
1699 }
1700 OF_EARLYCON_DECLARE(msm_serial, "qcom,msm-uart",
1701 msm_serial_early_console_setup);
1702
1703 static void
1704 msm_serial_early_write_dm(struct console *con, const char *s, unsigned n)
1705 {
1706 struct earlycon_device *dev = con->data;
1707
1708 __msm_console_write(&dev->port, s, n, true);
1709 }
1710
1711 static int __init
1712 msm_serial_early_console_setup_dm(struct earlycon_device *device,
1713 const char *opt)
1714 {
1715 if (!device->port.membase)
1716 return -ENODEV;
1717
1718 device->con->write = msm_serial_early_write_dm;
1719 return 0;
1720 }
1721 OF_EARLYCON_DECLARE(msm_serial_dm, "qcom,msm-uartdm",
1722 msm_serial_early_console_setup_dm);
1723
1724 static struct uart_driver msm_uart_driver;
1725
1726 static struct console msm_console = {
1727 .name = "ttyMSM",
1728 .write = msm_console_write,
1729 .device = uart_console_device,
1730 .setup = msm_console_setup,
1731 .flags = CON_PRINTBUFFER,
1732 .index = -1,
1733 .data = &msm_uart_driver,
1734 };
1735
1736 #define MSM_CONSOLE (&msm_console)
1737
1738 #else
1739 #define MSM_CONSOLE NULL
1740 #endif
1741
1742 static struct uart_driver msm_uart_driver = {
1743 .owner = THIS_MODULE,
1744 .driver_name = "msm_serial",
1745 .dev_name = "ttyMSM",
1746 .nr = UART_NR,
1747 .cons = MSM_CONSOLE,
1748 };
1749
1750 static atomic_t msm_uart_next_id = ATOMIC_INIT(0);
1751
1752 static const struct of_device_id msm_uartdm_table[] = {
1753 { .compatible = "qcom,msm-uartdm-v1.1", .data = (void *)UARTDM_1P1 },
1754 { .compatible = "qcom,msm-uartdm-v1.2", .data = (void *)UARTDM_1P2 },
1755 { .compatible = "qcom,msm-uartdm-v1.3", .data = (void *)UARTDM_1P3 },
1756 { .compatible = "qcom,msm-uartdm-v1.4", .data = (void *)UARTDM_1P4 },
1757 { }
1758 };
1759
1760 static int msm_serial_probe(struct platform_device *pdev)
1761 {
1762 struct msm_port *msm_port;
1763 struct resource *resource;
1764 struct uart_port *port;
1765 const struct of_device_id *id;
1766 int irq, line;
1767
1768 if (pdev->dev.of_node)
1769 line = of_alias_get_id(pdev->dev.of_node, "serial");
1770 else
1771 line = pdev->id;
1772
1773 if (line < 0)
1774 line = atomic_inc_return(&msm_uart_next_id) - 1;
1775
1776 if (unlikely(line < 0 || line >= UART_NR))
1777 return -ENXIO;
1778
1779 dev_info(&pdev->dev, "msm_serial: detected port #%d\n", line);
1780
1781 port = msm_get_port_from_line(line);
1782 port->dev = &pdev->dev;
1783 msm_port = UART_TO_MSM(port);
1784
1785 id = of_match_device(msm_uartdm_table, &pdev->dev);
1786 if (id)
1787 msm_port->is_uartdm = (unsigned long)id->data;
1788 else
1789 msm_port->is_uartdm = 0;
1790
1791 msm_port->clk = devm_clk_get(&pdev->dev, "core");
1792 if (IS_ERR(msm_port->clk))
1793 return PTR_ERR(msm_port->clk);
1794
1795 if (msm_port->is_uartdm) {
1796 msm_port->pclk = devm_clk_get(&pdev->dev, "iface");
1797 if (IS_ERR(msm_port->pclk))
1798 return PTR_ERR(msm_port->pclk);
1799 }
1800
1801 port->uartclk = clk_get_rate(msm_port->clk);
1802 dev_info(&pdev->dev, "uartclk = %d\n", port->uartclk);
1803
1804 resource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1805 if (unlikely(!resource))
1806 return -ENXIO;
1807 port->mapbase = resource->start;
1808
1809 irq = platform_get_irq(pdev, 0);
1810 if (unlikely(irq < 0))
1811 return -ENXIO;
1812 port->irq = irq;
1813
1814 platform_set_drvdata(pdev, port);
1815
1816 return uart_add_one_port(&msm_uart_driver, port);
1817 }
1818
1819 static int msm_serial_remove(struct platform_device *pdev)
1820 {
1821 struct uart_port *port = platform_get_drvdata(pdev);
1822
1823 uart_remove_one_port(&msm_uart_driver, port);
1824
1825 return 0;
1826 }
1827
1828 static const struct of_device_id msm_match_table[] = {
1829 { .compatible = "qcom,msm-uart" },
1830 { .compatible = "qcom,msm-uartdm" },
1831 {}
1832 };
1833 MODULE_DEVICE_TABLE(of, msm_match_table);
1834
1835 static int __maybe_unused msm_serial_suspend(struct device *dev)
1836 {
1837 struct msm_port *port = dev_get_drvdata(dev);
1838
1839 uart_suspend_port(&msm_uart_driver, &port->uart);
1840
1841 return 0;
1842 }
1843
1844 static int __maybe_unused msm_serial_resume(struct device *dev)
1845 {
1846 struct msm_port *port = dev_get_drvdata(dev);
1847
1848 uart_resume_port(&msm_uart_driver, &port->uart);
1849
1850 return 0;
1851 }
1852
1853 static const struct dev_pm_ops msm_serial_dev_pm_ops = {
1854 SET_SYSTEM_SLEEP_PM_OPS(msm_serial_suspend, msm_serial_resume)
1855 };
1856
1857 static struct platform_driver msm_platform_driver = {
1858 .remove = msm_serial_remove,
1859 .probe = msm_serial_probe,
1860 .driver = {
1861 .name = "msm_serial",
1862 .pm = &msm_serial_dev_pm_ops,
1863 .of_match_table = msm_match_table,
1864 },
1865 };
1866
1867 static int __init msm_serial_init(void)
1868 {
1869 int ret;
1870
1871 ret = uart_register_driver(&msm_uart_driver);
1872 if (unlikely(ret))
1873 return ret;
1874
1875 ret = platform_driver_register(&msm_platform_driver);
1876 if (unlikely(ret))
1877 uart_unregister_driver(&msm_uart_driver);
1878
1879 pr_info("msm_serial: driver initialized\n");
1880
1881 return ret;
1882 }
1883
1884 static void __exit msm_serial_exit(void)
1885 {
1886 platform_driver_unregister(&msm_platform_driver);
1887 uart_unregister_driver(&msm_uart_driver);
1888 }
1889
1890 module_init(msm_serial_init);
1891 module_exit(msm_serial_exit);
1892
1893 MODULE_AUTHOR("Robert Love <rlove@google.com>");
1894 MODULE_DESCRIPTION("Driver for msm7x serial device");
1895 MODULE_LICENSE("GPL");
Linux with added FPC-III support