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Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/evalenti/linux...
[linux/fpc-iii.git] / drivers / tty / serial / serial-tegra.c
blob1d6fc60ed01332da1dfebfade8065e57565d124a
1 /*
2 * serial_tegra.c
3 *
4 * High-speed serial driver for NVIDIA Tegra SoCs
5 *
6 * Copyright (c) 2012-2013, NVIDIA CORPORATION. All rights reserved.
7 *
8 * Author: Laxman Dewangan <ldewangan@nvidia.com>
9 *
10 * This program is free software; you can redistribute it and/or modify it
11 * under the terms and conditions of the GNU General Public License,
12 * version 2, as published by the Free Software Foundation.
13 *
14 * This program is distributed in the hope it will be useful, but WITHOUT
15 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
16 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
17 * more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program. If not, see <http://www.gnu.org/licenses/>.
21 */
22
23 #include <linux/clk.h>
24 #include <linux/debugfs.h>
25 #include <linux/delay.h>
26 #include <linux/dmaengine.h>
27 #include <linux/dma-mapping.h>
28 #include <linux/dmapool.h>
29 #include <linux/err.h>
30 #include <linux/io.h>
31 #include <linux/irq.h>
32 #include <linux/module.h>
33 #include <linux/of.h>
34 #include <linux/of_device.h>
35 #include <linux/pagemap.h>
36 #include <linux/platform_device.h>
37 #include <linux/reset.h>
38 #include <linux/serial.h>
39 #include <linux/serial_8250.h>
40 #include <linux/serial_core.h>
41 #include <linux/serial_reg.h>
42 #include <linux/slab.h>
43 #include <linux/string.h>
44 #include <linux/termios.h>
45 #include <linux/tty.h>
46 #include <linux/tty_flip.h>
47
48 #define TEGRA_UART_TYPE "TEGRA_UART"
49 #define TX_EMPTY_STATUS (UART_LSR_TEMT | UART_LSR_THRE)
50 #define BYTES_TO_ALIGN(x) ((unsigned long)(x) & 0x3)
51
52 #define TEGRA_UART_RX_DMA_BUFFER_SIZE 4096
53 #define TEGRA_UART_LSR_TXFIFO_FULL 0x100
54 #define TEGRA_UART_IER_EORD 0x20
55 #define TEGRA_UART_MCR_RTS_EN 0x40
56 #define TEGRA_UART_MCR_CTS_EN 0x20
57 #define TEGRA_UART_LSR_ANY (UART_LSR_OE | UART_LSR_BI | \
58 UART_LSR_PE | UART_LSR_FE)
59 #define TEGRA_UART_IRDA_CSR 0x08
60 #define TEGRA_UART_SIR_ENABLED 0x80
61
62 #define TEGRA_UART_TX_PIO 1
63 #define TEGRA_UART_TX_DMA 2
64 #define TEGRA_UART_MIN_DMA 16
65 #define TEGRA_UART_FIFO_SIZE 32
66
67 /*
68 * Tx fifo trigger level setting in tegra uart is in
69 * reverse way then conventional uart.
70 */
71 #define TEGRA_UART_TX_TRIG_16B 0x00
72 #define TEGRA_UART_TX_TRIG_8B 0x10
73 #define TEGRA_UART_TX_TRIG_4B 0x20
74 #define TEGRA_UART_TX_TRIG_1B 0x30
75
76 #define TEGRA_UART_MAXIMUM 5
77
78 /* Default UART setting when started: 115200 no parity, stop, 8 data bits */
79 #define TEGRA_UART_DEFAULT_BAUD 115200
80 #define TEGRA_UART_DEFAULT_LSR UART_LCR_WLEN8
81
82 /* Tx transfer mode */
83 #define TEGRA_TX_PIO 1
84 #define TEGRA_TX_DMA 2
85
86 /**
87 * tegra_uart_chip_data: SOC specific data.
88 *
89 * @tx_fifo_full_status: Status flag available for checking tx fifo full.
90 * @allow_txfifo_reset_fifo_mode: allow_tx fifo reset with fifo mode or not.
91 * Tegra30 does not allow this.
92 * @support_clk_src_div: Clock source support the clock divider.
93 */
94 struct tegra_uart_chip_data {
95 bool tx_fifo_full_status;
96 bool allow_txfifo_reset_fifo_mode;
97 bool support_clk_src_div;
98 };
99
100 struct tegra_uart_port {
101 struct uart_port uport;
102 const struct tegra_uart_chip_data *cdata;
103
104 struct clk *uart_clk;
105 struct reset_control *rst;
106 unsigned int current_baud;
107
108 /* Register shadow */
109 unsigned long fcr_shadow;
110 unsigned long mcr_shadow;
111 unsigned long lcr_shadow;
112 unsigned long ier_shadow;
113 bool rts_active;
114
115 int tx_in_progress;
116 unsigned int tx_bytes;
117
118 bool enable_modem_interrupt;
119
120 bool rx_timeout;
121 int rx_in_progress;
122 int symb_bit;
123
124 struct dma_chan *rx_dma_chan;
125 struct dma_chan *tx_dma_chan;
126 dma_addr_t rx_dma_buf_phys;
127 dma_addr_t tx_dma_buf_phys;
128 unsigned char *rx_dma_buf_virt;
129 unsigned char *tx_dma_buf_virt;
130 struct dma_async_tx_descriptor *tx_dma_desc;
131 struct dma_async_tx_descriptor *rx_dma_desc;
132 dma_cookie_t tx_cookie;
133 dma_cookie_t rx_cookie;
134 unsigned int tx_bytes_requested;
135 unsigned int rx_bytes_requested;
136 };
137
138 static void tegra_uart_start_next_tx(struct tegra_uart_port *tup);
139 static int tegra_uart_start_rx_dma(struct tegra_uart_port *tup);
140
141 static inline unsigned long tegra_uart_read(struct tegra_uart_port *tup,
142 unsigned long reg)
143 {
144 return readl(tup->uport.membase + (reg << tup->uport.regshift));
145 }
146
147 static inline void tegra_uart_write(struct tegra_uart_port *tup, unsigned val,
148 unsigned long reg)
149 {
150 writel(val, tup->uport.membase + (reg << tup->uport.regshift));
151 }
152
153 static inline struct tegra_uart_port *to_tegra_uport(struct uart_port *u)
154 {
155 return container_of(u, struct tegra_uart_port, uport);
156 }
157
158 static unsigned int tegra_uart_get_mctrl(struct uart_port *u)
159 {
160 struct tegra_uart_port *tup = to_tegra_uport(u);
161
162 /*
163 * RI - Ring detector is active
164 * CD/DCD/CAR - Carrier detect is always active. For some reason
165 * linux has different names for carrier detect.
166 * DSR - Data Set ready is active as the hardware doesn't support it.
167 * Don't know if the linux support this yet?
168 * CTS - Clear to send. Always set to active, as the hardware handles
169 * CTS automatically.
170 */
171 if (tup->enable_modem_interrupt)
172 return TIOCM_RI | TIOCM_CD | TIOCM_DSR | TIOCM_CTS;
173 return TIOCM_CTS;
174 }
175
176 static void set_rts(struct tegra_uart_port *tup, bool active)
177 {
178 unsigned long mcr;
179
180 mcr = tup->mcr_shadow;
181 if (active)
182 mcr |= TEGRA_UART_MCR_RTS_EN;
183 else
184 mcr &= ~TEGRA_UART_MCR_RTS_EN;
185 if (mcr != tup->mcr_shadow) {
186 tegra_uart_write(tup, mcr, UART_MCR);
187 tup->mcr_shadow = mcr;
188 }
189 }
190
191 static void set_dtr(struct tegra_uart_port *tup, bool active)
192 {
193 unsigned long mcr;
194
195 mcr = tup->mcr_shadow;
196 if (active)
197 mcr |= UART_MCR_DTR;
198 else
199 mcr &= ~UART_MCR_DTR;
200 if (mcr != tup->mcr_shadow) {
201 tegra_uart_write(tup, mcr, UART_MCR);
202 tup->mcr_shadow = mcr;
203 }
204 }
205
206 static void tegra_uart_set_mctrl(struct uart_port *u, unsigned int mctrl)
207 {
208 struct tegra_uart_port *tup = to_tegra_uport(u);
209 unsigned long mcr;
210 int dtr_enable;
211
212 mcr = tup->mcr_shadow;
213 tup->rts_active = !!(mctrl & TIOCM_RTS);
214 set_rts(tup, tup->rts_active);
215
216 dtr_enable = !!(mctrl & TIOCM_DTR);
217 set_dtr(tup, dtr_enable);
218 }
219
220 static void tegra_uart_break_ctl(struct uart_port *u, int break_ctl)
221 {
222 struct tegra_uart_port *tup = to_tegra_uport(u);
223 unsigned long lcr;
224
225 lcr = tup->lcr_shadow;
226 if (break_ctl)
227 lcr |= UART_LCR_SBC;
228 else
229 lcr &= ~UART_LCR_SBC;
230 tegra_uart_write(tup, lcr, UART_LCR);
231 tup->lcr_shadow = lcr;
232 }
233
234 /**
235 * tegra_uart_wait_cycle_time: Wait for N UART clock periods
236 *
237 * @tup: Tegra serial port data structure.
238 * @cycles: Number of clock periods to wait.
239 *
240 * Tegra UARTs are clocked at 16X the baud/bit rate and hence the UART
241 * clock speed is 16X the current baud rate.
242 */
243 static void tegra_uart_wait_cycle_time(struct tegra_uart_port *tup,
244 unsigned int cycles)
245 {
246 if (tup->current_baud)
247 udelay(DIV_ROUND_UP(cycles * 1000000, tup->current_baud * 16));
248 }
249
250 /* Wait for a symbol-time. */
251 static void tegra_uart_wait_sym_time(struct tegra_uart_port *tup,
252 unsigned int syms)
253 {
254 if (tup->current_baud)
255 udelay(DIV_ROUND_UP(syms * tup->symb_bit * 1000000,
256 tup->current_baud));
257 }
258
259 static void tegra_uart_fifo_reset(struct tegra_uart_port *tup, u8 fcr_bits)
260 {
261 unsigned long fcr = tup->fcr_shadow;
262
263 if (tup->cdata->allow_txfifo_reset_fifo_mode) {
264 fcr |= fcr_bits & (UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
265 tegra_uart_write(tup, fcr, UART_FCR);
266 } else {
267 fcr &= ~UART_FCR_ENABLE_FIFO;
268 tegra_uart_write(tup, fcr, UART_FCR);
269 udelay(60);
270 fcr |= fcr_bits & (UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
271 tegra_uart_write(tup, fcr, UART_FCR);
272 fcr |= UART_FCR_ENABLE_FIFO;
273 tegra_uart_write(tup, fcr, UART_FCR);
274 }
275
276 /* Dummy read to ensure the write is posted */
277 tegra_uart_read(tup, UART_SCR);
278
279 /*
280 * For all tegra devices (up to t210), there is a hardware issue that
281 * requires software to wait for 32 UART clock periods for the flush
282 * to propagate, otherwise data could be lost.
283 */
284 tegra_uart_wait_cycle_time(tup, 32);
285 }
286
287 static int tegra_set_baudrate(struct tegra_uart_port *tup, unsigned int baud)
288 {
289 unsigned long rate;
290 unsigned int divisor;
291 unsigned long lcr;
292 int ret;
293
294 if (tup->current_baud == baud)
295 return 0;
296
297 if (tup->cdata->support_clk_src_div) {
298 rate = baud * 16;
299 ret = clk_set_rate(tup->uart_clk, rate);
300 if (ret < 0) {
301 dev_err(tup->uport.dev,
302 "clk_set_rate() failed for rate %lu\n", rate);
303 return ret;
304 }
305 divisor = 1;
306 } else {
307 rate = clk_get_rate(tup->uart_clk);
308 divisor = DIV_ROUND_CLOSEST(rate, baud * 16);
309 }
310
311 lcr = tup->lcr_shadow;
312 lcr |= UART_LCR_DLAB;
313 tegra_uart_write(tup, lcr, UART_LCR);
314
315 tegra_uart_write(tup, divisor & 0xFF, UART_TX);
316 tegra_uart_write(tup, ((divisor >> 8) & 0xFF), UART_IER);
317
318 lcr &= ~UART_LCR_DLAB;
319 tegra_uart_write(tup, lcr, UART_LCR);
320
321 /* Dummy read to ensure the write is posted */
322 tegra_uart_read(tup, UART_SCR);
323
324 tup->current_baud = baud;
325
326 /* wait two character intervals at new rate */
327 tegra_uart_wait_sym_time(tup, 2);
328 return 0;
329 }
330
331 static char tegra_uart_decode_rx_error(struct tegra_uart_port *tup,
332 unsigned long lsr)
333 {
334 char flag = TTY_NORMAL;
335
336 if (unlikely(lsr & TEGRA_UART_LSR_ANY)) {
337 if (lsr & UART_LSR_OE) {
338 /* Overrrun error */
339 flag = TTY_OVERRUN;
340 tup->uport.icount.overrun++;
341 dev_err(tup->uport.dev, "Got overrun errors\n");
342 } else if (lsr & UART_LSR_PE) {
343 /* Parity error */
344 flag = TTY_PARITY;
345 tup->uport.icount.parity++;
346 dev_err(tup->uport.dev, "Got Parity errors\n");
347 } else if (lsr & UART_LSR_FE) {
348 flag = TTY_FRAME;
349 tup->uport.icount.frame++;
350 dev_err(tup->uport.dev, "Got frame errors\n");
351 } else if (lsr & UART_LSR_BI) {
352 dev_err(tup->uport.dev, "Got Break\n");
353 tup->uport.icount.brk++;
354 /* If FIFO read error without any data, reset Rx FIFO */
355 if (!(lsr & UART_LSR_DR) && (lsr & UART_LSR_FIFOE))
356 tegra_uart_fifo_reset(tup, UART_FCR_CLEAR_RCVR);
357 }
358 }
359 return flag;
360 }
361
362 static int tegra_uart_request_port(struct uart_port *u)
363 {
364 return 0;
365 }
366
367 static void tegra_uart_release_port(struct uart_port *u)
368 {
369 /* Nothing to do here */
370 }
371
372 static void tegra_uart_fill_tx_fifo(struct tegra_uart_port *tup, int max_bytes)
373 {
374 struct circ_buf *xmit = &tup->uport.state->xmit;
375 int i;
376
377 for (i = 0; i < max_bytes; i++) {
378 BUG_ON(uart_circ_empty(xmit));
379 if (tup->cdata->tx_fifo_full_status) {
380 unsigned long lsr = tegra_uart_read(tup, UART_LSR);
381 if ((lsr & TEGRA_UART_LSR_TXFIFO_FULL))
382 break;
383 }
384 tegra_uart_write(tup, xmit->buf[xmit->tail], UART_TX);
385 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
386 tup->uport.icount.tx++;
387 }
388 }
389
390 static void tegra_uart_start_pio_tx(struct tegra_uart_port *tup,
391 unsigned int bytes)
392 {
393 if (bytes > TEGRA_UART_MIN_DMA)
394 bytes = TEGRA_UART_MIN_DMA;
395
396 tup->tx_in_progress = TEGRA_UART_TX_PIO;
397 tup->tx_bytes = bytes;
398 tup->ier_shadow |= UART_IER_THRI;
399 tegra_uart_write(tup, tup->ier_shadow, UART_IER);
400 }
401
402 static void tegra_uart_tx_dma_complete(void *args)
403 {
404 struct tegra_uart_port *tup = args;
405 struct circ_buf *xmit = &tup->uport.state->xmit;
406 struct dma_tx_state state;
407 unsigned long flags;
408 unsigned int count;
409
410 dmaengine_tx_status(tup->tx_dma_chan, tup->tx_cookie, &state);
411 count = tup->tx_bytes_requested - state.residue;
412 async_tx_ack(tup->tx_dma_desc);
413 spin_lock_irqsave(&tup->uport.lock, flags);
414 xmit->tail = (xmit->tail + count) & (UART_XMIT_SIZE - 1);
415 tup->tx_in_progress = 0;
416 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
417 uart_write_wakeup(&tup->uport);
418 tegra_uart_start_next_tx(tup);
419 spin_unlock_irqrestore(&tup->uport.lock, flags);
420 }
421
422 static int tegra_uart_start_tx_dma(struct tegra_uart_port *tup,
423 unsigned long count)
424 {
425 struct circ_buf *xmit = &tup->uport.state->xmit;
426 dma_addr_t tx_phys_addr;
427
428 dma_sync_single_for_device(tup->uport.dev, tup->tx_dma_buf_phys,
429 UART_XMIT_SIZE, DMA_TO_DEVICE);
430
431 tup->tx_bytes = count & ~(0xF);
432 tx_phys_addr = tup->tx_dma_buf_phys + xmit->tail;
433 tup->tx_dma_desc = dmaengine_prep_slave_single(tup->tx_dma_chan,
434 tx_phys_addr, tup->tx_bytes, DMA_MEM_TO_DEV,
435 DMA_PREP_INTERRUPT);
436 if (!tup->tx_dma_desc) {
437 dev_err(tup->uport.dev, "Not able to get desc for Tx\n");
438 return -EIO;
439 }
440
441 tup->tx_dma_desc->callback = tegra_uart_tx_dma_complete;
442 tup->tx_dma_desc->callback_param = tup;
443 tup->tx_in_progress = TEGRA_UART_TX_DMA;
444 tup->tx_bytes_requested = tup->tx_bytes;
445 tup->tx_cookie = dmaengine_submit(tup->tx_dma_desc);
446 dma_async_issue_pending(tup->tx_dma_chan);
447 return 0;
448 }
449
450 static void tegra_uart_start_next_tx(struct tegra_uart_port *tup)
451 {
452 unsigned long tail;
453 unsigned long count;
454 struct circ_buf *xmit = &tup->uport.state->xmit;
455
456 tail = (unsigned long)&xmit->buf[xmit->tail];
457 count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
458 if (!count)
459 return;
460
461 if (count < TEGRA_UART_MIN_DMA)
462 tegra_uart_start_pio_tx(tup, count);
463 else if (BYTES_TO_ALIGN(tail) > 0)
464 tegra_uart_start_pio_tx(tup, BYTES_TO_ALIGN(tail));
465 else
466 tegra_uart_start_tx_dma(tup, count);
467 }
468
469 /* Called by serial core driver with u->lock taken. */
470 static void tegra_uart_start_tx(struct uart_port *u)
471 {
472 struct tegra_uart_port *tup = to_tegra_uport(u);
473 struct circ_buf *xmit = &u->state->xmit;
474
475 if (!uart_circ_empty(xmit) && !tup->tx_in_progress)
476 tegra_uart_start_next_tx(tup);
477 }
478
479 static unsigned int tegra_uart_tx_empty(struct uart_port *u)
480 {
481 struct tegra_uart_port *tup = to_tegra_uport(u);
482 unsigned int ret = 0;
483 unsigned long flags;
484
485 spin_lock_irqsave(&u->lock, flags);
486 if (!tup->tx_in_progress) {
487 unsigned long lsr = tegra_uart_read(tup, UART_LSR);
488 if ((lsr & TX_EMPTY_STATUS) == TX_EMPTY_STATUS)
489 ret = TIOCSER_TEMT;
490 }
491 spin_unlock_irqrestore(&u->lock, flags);
492 return ret;
493 }
494
495 static void tegra_uart_stop_tx(struct uart_port *u)
496 {
497 struct tegra_uart_port *tup = to_tegra_uport(u);
498 struct circ_buf *xmit = &tup->uport.state->xmit;
499 struct dma_tx_state state;
500 unsigned int count;
501
502 if (tup->tx_in_progress != TEGRA_UART_TX_DMA)
503 return;
504
505 dmaengine_terminate_all(tup->tx_dma_chan);
506 dmaengine_tx_status(tup->tx_dma_chan, tup->tx_cookie, &state);
507 count = tup->tx_bytes_requested - state.residue;
508 async_tx_ack(tup->tx_dma_desc);
509 xmit->tail = (xmit->tail + count) & (UART_XMIT_SIZE - 1);
510 tup->tx_in_progress = 0;
511 }
512
513 static void tegra_uart_handle_tx_pio(struct tegra_uart_port *tup)
514 {
515 struct circ_buf *xmit = &tup->uport.state->xmit;
516
517 tegra_uart_fill_tx_fifo(tup, tup->tx_bytes);
518 tup->tx_in_progress = 0;
519 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
520 uart_write_wakeup(&tup->uport);
521 tegra_uart_start_next_tx(tup);
522 }
523
524 static void tegra_uart_handle_rx_pio(struct tegra_uart_port *tup,
525 struct tty_port *tty)
526 {
527 do {
528 char flag = TTY_NORMAL;
529 unsigned long lsr = 0;
530 unsigned char ch;
531
532 lsr = tegra_uart_read(tup, UART_LSR);
533 if (!(lsr & UART_LSR_DR))
534 break;
535
536 flag = tegra_uart_decode_rx_error(tup, lsr);
537 ch = (unsigned char) tegra_uart_read(tup, UART_RX);
538 tup->uport.icount.rx++;
539
540 if (!uart_handle_sysrq_char(&tup->uport, ch) && tty)
541 tty_insert_flip_char(tty, ch, flag);
542 } while (1);
543 }
544
545 static void tegra_uart_copy_rx_to_tty(struct tegra_uart_port *tup,
546 struct tty_port *tty,
547 unsigned int count)
548 {
549 int copied;
550
551 /* If count is zero, then there is no data to be copied */
552 if (!count)
553 return;
554
555 tup->uport.icount.rx += count;
556 if (!tty) {
557 dev_err(tup->uport.dev, "No tty port\n");
558 return;
559 }
560 dma_sync_single_for_cpu(tup->uport.dev, tup->rx_dma_buf_phys,
561 TEGRA_UART_RX_DMA_BUFFER_SIZE, DMA_FROM_DEVICE);
562 copied = tty_insert_flip_string(tty,
563 ((unsigned char *)(tup->rx_dma_buf_virt)), count);
564 if (copied != count) {
565 WARN_ON(1);
566 dev_err(tup->uport.dev, "RxData copy to tty layer failed\n");
567 }
568 dma_sync_single_for_device(tup->uport.dev, tup->rx_dma_buf_phys,
569 TEGRA_UART_RX_DMA_BUFFER_SIZE, DMA_TO_DEVICE);
570 }
571
572 static void tegra_uart_rx_buffer_push(struct tegra_uart_port *tup,
573 unsigned int residue)
574 {
575 struct tty_port *port = &tup->uport.state->port;
576 struct tty_struct *tty = tty_port_tty_get(port);
577 unsigned int count;
578
579 async_tx_ack(tup->rx_dma_desc);
580 count = tup->rx_bytes_requested - residue;
581
582 /* If we are here, DMA is stopped */
583 tegra_uart_copy_rx_to_tty(tup, port, count);
584
585 tegra_uart_handle_rx_pio(tup, port);
586 if (tty) {
587 tty_flip_buffer_push(port);
588 tty_kref_put(tty);
589 }
590 }
591
592 static void tegra_uart_rx_dma_complete(void *args)
593 {
594 struct tegra_uart_port *tup = args;
595 struct uart_port *u = &tup->uport;
596 unsigned long flags;
597 struct dma_tx_state state;
598 enum dma_status status;
599
600 spin_lock_irqsave(&u->lock, flags);
601
602 status = dmaengine_tx_status(tup->rx_dma_chan, tup->rx_cookie, &state);
603
604 if (status == DMA_IN_PROGRESS) {
605 dev_dbg(tup->uport.dev, "RX DMA is in progress\n");
606 goto done;
607 }
608
609 /* Deactivate flow control to stop sender */
610 if (tup->rts_active)
611 set_rts(tup, false);
612
613 tegra_uart_rx_buffer_push(tup, 0);
614 tegra_uart_start_rx_dma(tup);
615
616 /* Activate flow control to start transfer */
617 if (tup->rts_active)
618 set_rts(tup, true);
619
620 done:
621 spin_unlock_irqrestore(&u->lock, flags);
622 }
623
624 static void tegra_uart_handle_rx_dma(struct tegra_uart_port *tup)
625 {
626 struct dma_tx_state state;
627
628 /* Deactivate flow control to stop sender */
629 if (tup->rts_active)
630 set_rts(tup, false);
631
632 dmaengine_terminate_all(tup->rx_dma_chan);
633 dmaengine_tx_status(tup->rx_dma_chan, tup->rx_cookie, &state);
634 tegra_uart_rx_buffer_push(tup, state.residue);
635 tegra_uart_start_rx_dma(tup);
636
637 if (tup->rts_active)
638 set_rts(tup, true);
639 }
640
641 static int tegra_uart_start_rx_dma(struct tegra_uart_port *tup)
642 {
643 unsigned int count = TEGRA_UART_RX_DMA_BUFFER_SIZE;
644
645 tup->rx_dma_desc = dmaengine_prep_slave_single(tup->rx_dma_chan,
646 tup->rx_dma_buf_phys, count, DMA_DEV_TO_MEM,
647 DMA_PREP_INTERRUPT);
648 if (!tup->rx_dma_desc) {
649 dev_err(tup->uport.dev, "Not able to get desc for Rx\n");
650 return -EIO;
651 }
652
653 tup->rx_dma_desc->callback = tegra_uart_rx_dma_complete;
654 tup->rx_dma_desc->callback_param = tup;
655 dma_sync_single_for_device(tup->uport.dev, tup->rx_dma_buf_phys,
656 count, DMA_TO_DEVICE);
657 tup->rx_bytes_requested = count;
658 tup->rx_cookie = dmaengine_submit(tup->rx_dma_desc);
659 dma_async_issue_pending(tup->rx_dma_chan);
660 return 0;
661 }
662
663 static void tegra_uart_handle_modem_signal_change(struct uart_port *u)
664 {
665 struct tegra_uart_port *tup = to_tegra_uport(u);
666 unsigned long msr;
667
668 msr = tegra_uart_read(tup, UART_MSR);
669 if (!(msr & UART_MSR_ANY_DELTA))
670 return;
671
672 if (msr & UART_MSR_TERI)
673 tup->uport.icount.rng++;
674 if (msr & UART_MSR_DDSR)
675 tup->uport.icount.dsr++;
676 /* We may only get DDCD when HW init and reset */
677 if (msr & UART_MSR_DDCD)
678 uart_handle_dcd_change(&tup->uport, msr & UART_MSR_DCD);
679 /* Will start/stop_tx accordingly */
680 if (msr & UART_MSR_DCTS)
681 uart_handle_cts_change(&tup->uport, msr & UART_MSR_CTS);
682 }
683
684 static irqreturn_t tegra_uart_isr(int irq, void *data)
685 {
686 struct tegra_uart_port *tup = data;
687 struct uart_port *u = &tup->uport;
688 unsigned long iir;
689 unsigned long ier;
690 bool is_rx_int = false;
691 unsigned long flags;
692
693 spin_lock_irqsave(&u->lock, flags);
694 while (1) {
695 iir = tegra_uart_read(tup, UART_IIR);
696 if (iir & UART_IIR_NO_INT) {
697 if (is_rx_int) {
698 tegra_uart_handle_rx_dma(tup);
699 if (tup->rx_in_progress) {
700 ier = tup->ier_shadow;
701 ier |= (UART_IER_RLSI | UART_IER_RTOIE |
702 TEGRA_UART_IER_EORD);
703 tup->ier_shadow = ier;
704 tegra_uart_write(tup, ier, UART_IER);
705 }
706 }
707 spin_unlock_irqrestore(&u->lock, flags);
708 return IRQ_HANDLED;
709 }
710
711 switch ((iir >> 1) & 0x7) {
712 case 0: /* Modem signal change interrupt */
713 tegra_uart_handle_modem_signal_change(u);
714 break;
715
716 case 1: /* Transmit interrupt only triggered when using PIO */
717 tup->ier_shadow &= ~UART_IER_THRI;
718 tegra_uart_write(tup, tup->ier_shadow, UART_IER);
719 tegra_uart_handle_tx_pio(tup);
720 break;
721
722 case 4: /* End of data */
723 case 6: /* Rx timeout */
724 case 2: /* Receive */
725 if (!is_rx_int) {
726 is_rx_int = true;
727 /* Disable Rx interrupts */
728 ier = tup->ier_shadow;
729 ier |= UART_IER_RDI;
730 tegra_uart_write(tup, ier, UART_IER);
731 ier &= ~(UART_IER_RDI | UART_IER_RLSI |
732 UART_IER_RTOIE | TEGRA_UART_IER_EORD);
733 tup->ier_shadow = ier;
734 tegra_uart_write(tup, ier, UART_IER);
735 }
736 break;
737
738 case 3: /* Receive error */
739 tegra_uart_decode_rx_error(tup,
740 tegra_uart_read(tup, UART_LSR));
741 break;
742
743 case 5: /* break nothing to handle */
744 case 7: /* break nothing to handle */
745 break;
746 }
747 }
748 }
749
750 static void tegra_uart_stop_rx(struct uart_port *u)
751 {
752 struct tegra_uart_port *tup = to_tegra_uport(u);
753 struct dma_tx_state state;
754 unsigned long ier;
755
756 if (tup->rts_active)
757 set_rts(tup, false);
758
759 if (!tup->rx_in_progress)
760 return;
761
762 tegra_uart_wait_sym_time(tup, 1); /* wait a character interval */
763
764 ier = tup->ier_shadow;
765 ier &= ~(UART_IER_RDI | UART_IER_RLSI | UART_IER_RTOIE |
766 TEGRA_UART_IER_EORD);
767 tup->ier_shadow = ier;
768 tegra_uart_write(tup, ier, UART_IER);
769 tup->rx_in_progress = 0;
770 dmaengine_terminate_all(tup->rx_dma_chan);
771 dmaengine_tx_status(tup->rx_dma_chan, tup->rx_cookie, &state);
772 tegra_uart_rx_buffer_push(tup, state.residue);
773 }
774
775 static void tegra_uart_hw_deinit(struct tegra_uart_port *tup)
776 {
777 unsigned long flags;
778 unsigned long char_time = DIV_ROUND_UP(10000000, tup->current_baud);
779 unsigned long fifo_empty_time = tup->uport.fifosize * char_time;
780 unsigned long wait_time;
781 unsigned long lsr;
782 unsigned long msr;
783 unsigned long mcr;
784
785 /* Disable interrupts */
786 tegra_uart_write(tup, 0, UART_IER);
787
788 lsr = tegra_uart_read(tup, UART_LSR);
789 if ((lsr & UART_LSR_TEMT) != UART_LSR_TEMT) {
790 msr = tegra_uart_read(tup, UART_MSR);
791 mcr = tegra_uart_read(tup, UART_MCR);
792 if ((mcr & TEGRA_UART_MCR_CTS_EN) && (msr & UART_MSR_CTS))
793 dev_err(tup->uport.dev,
794 "Tx Fifo not empty, CTS disabled, waiting\n");
795
796 /* Wait for Tx fifo to be empty */
797 while ((lsr & UART_LSR_TEMT) != UART_LSR_TEMT) {
798 wait_time = min(fifo_empty_time, 100lu);
799 udelay(wait_time);
800 fifo_empty_time -= wait_time;
801 if (!fifo_empty_time) {
802 msr = tegra_uart_read(tup, UART_MSR);
803 mcr = tegra_uart_read(tup, UART_MCR);
804 if ((mcr & TEGRA_UART_MCR_CTS_EN) &&
805 (msr & UART_MSR_CTS))
806 dev_err(tup->uport.dev,
807 "Slave not ready\n");
808 break;
809 }
810 lsr = tegra_uart_read(tup, UART_LSR);
811 }
812 }
813
814 spin_lock_irqsave(&tup->uport.lock, flags);
815 /* Reset the Rx and Tx FIFOs */
816 tegra_uart_fifo_reset(tup, UART_FCR_CLEAR_XMIT | UART_FCR_CLEAR_RCVR);
817 tup->current_baud = 0;
818 spin_unlock_irqrestore(&tup->uport.lock, flags);
819
820 clk_disable_unprepare(tup->uart_clk);
821 }
822
823 static int tegra_uart_hw_init(struct tegra_uart_port *tup)
824 {
825 int ret;
826
827 tup->fcr_shadow = 0;
828 tup->mcr_shadow = 0;
829 tup->lcr_shadow = 0;
830 tup->ier_shadow = 0;
831 tup->current_baud = 0;
832
833 clk_prepare_enable(tup->uart_clk);
834
835 /* Reset the UART controller to clear all previous status.*/
836 reset_control_assert(tup->rst);
837 udelay(10);
838 reset_control_deassert(tup->rst);
839
840 tup->rx_in_progress = 0;
841 tup->tx_in_progress = 0;
842
843 /*
844 * Set the trigger level
845 *
846 * For PIO mode:
847 *
848 * For receive, this will interrupt the CPU after that many number of
849 * bytes are received, for the remaining bytes the receive timeout
850 * interrupt is received. Rx high watermark is set to 4.
851 *
852 * For transmit, if the trasnmit interrupt is enabled, this will
853 * interrupt the CPU when the number of entries in the FIFO reaches the
854 * low watermark. Tx low watermark is set to 16 bytes.
855 *
856 * For DMA mode:
857 *
858 * Set the Tx trigger to 16. This should match the DMA burst size that
859 * programmed in the DMA registers.
860 */
861 tup->fcr_shadow = UART_FCR_ENABLE_FIFO;
862 tup->fcr_shadow |= UART_FCR_R_TRIG_01;
863 tup->fcr_shadow |= TEGRA_UART_TX_TRIG_16B;
864 tegra_uart_write(tup, tup->fcr_shadow, UART_FCR);
865
866 /* Dummy read to ensure the write is posted */
867 tegra_uart_read(tup, UART_SCR);
868
869 /*
870 * For all tegra devices (up to t210), there is a hardware issue that
871 * requires software to wait for 3 UART clock periods after enabling
872 * the TX fifo, otherwise data could be lost.
873 */
874 tegra_uart_wait_cycle_time(tup, 3);
875
876 /*
877 * Initialize the UART with default configuration
878 * (115200, N, 8, 1) so that the receive DMA buffer may be
879 * enqueued
880 */
881 tup->lcr_shadow = TEGRA_UART_DEFAULT_LSR;
882 tegra_set_baudrate(tup, TEGRA_UART_DEFAULT_BAUD);
883 tup->fcr_shadow |= UART_FCR_DMA_SELECT;
884 tegra_uart_write(tup, tup->fcr_shadow, UART_FCR);
885
886 ret = tegra_uart_start_rx_dma(tup);
887 if (ret < 0) {
888 dev_err(tup->uport.dev, "Not able to start Rx DMA\n");
889 return ret;
890 }
891 tup->rx_in_progress = 1;
892
893 /*
894 * Enable IE_RXS for the receive status interrupts like line errros.
895 * Enable IE_RX_TIMEOUT to get the bytes which cannot be DMA'd.
896 *
897 * If using DMA mode, enable EORD instead of receive interrupt which
898 * will interrupt after the UART is done with the receive instead of
899 * the interrupt when the FIFO "threshold" is reached.
900 *
901 * EORD is different interrupt than RX_TIMEOUT - RX_TIMEOUT occurs when
902 * the DATA is sitting in the FIFO and couldn't be transferred to the
903 * DMA as the DMA size alignment(4 bytes) is not met. EORD will be
904 * triggered when there is a pause of the incomming data stream for 4
905 * characters long.
906 *
907 * For pauses in the data which is not aligned to 4 bytes, we get
908 * both the EORD as well as RX_TIMEOUT - SW sees RX_TIMEOUT first
909 * then the EORD.
910 */
911 tup->ier_shadow = UART_IER_RLSI | UART_IER_RTOIE | TEGRA_UART_IER_EORD;
912 tegra_uart_write(tup, tup->ier_shadow, UART_IER);
913 return 0;
914 }
915
916 static void tegra_uart_dma_channel_free(struct tegra_uart_port *tup,
917 bool dma_to_memory)
918 {
919 if (dma_to_memory) {
920 dmaengine_terminate_all(tup->rx_dma_chan);
921 dma_release_channel(tup->rx_dma_chan);
922 dma_free_coherent(tup->uport.dev, TEGRA_UART_RX_DMA_BUFFER_SIZE,
923 tup->rx_dma_buf_virt, tup->rx_dma_buf_phys);
924 tup->rx_dma_chan = NULL;
925 tup->rx_dma_buf_phys = 0;
926 tup->rx_dma_buf_virt = NULL;
927 } else {
928 dmaengine_terminate_all(tup->tx_dma_chan);
929 dma_release_channel(tup->tx_dma_chan);
930 dma_unmap_single(tup->uport.dev, tup->tx_dma_buf_phys,
931 UART_XMIT_SIZE, DMA_TO_DEVICE);
932 tup->tx_dma_chan = NULL;
933 tup->tx_dma_buf_phys = 0;
934 tup->tx_dma_buf_virt = NULL;
935 }
936 }
937
938 static int tegra_uart_dma_channel_allocate(struct tegra_uart_port *tup,
939 bool dma_to_memory)
940 {
941 struct dma_chan *dma_chan;
942 unsigned char *dma_buf;
943 dma_addr_t dma_phys;
944 int ret;
945 struct dma_slave_config dma_sconfig;
946
947 dma_chan = dma_request_slave_channel_reason(tup->uport.dev,
948 dma_to_memory ? "rx" : "tx");
949 if (IS_ERR(dma_chan)) {
950 ret = PTR_ERR(dma_chan);
951 dev_err(tup->uport.dev,
952 "DMA channel alloc failed: %d\n", ret);
953 return ret;
954 }
955
956 if (dma_to_memory) {
957 dma_buf = dma_alloc_coherent(tup->uport.dev,
958 TEGRA_UART_RX_DMA_BUFFER_SIZE,
959 &dma_phys, GFP_KERNEL);
960 if (!dma_buf) {
961 dev_err(tup->uport.dev,
962 "Not able to allocate the dma buffer\n");
963 dma_release_channel(dma_chan);
964 return -ENOMEM;
965 }
966 dma_sconfig.src_addr = tup->uport.mapbase;
967 dma_sconfig.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
968 dma_sconfig.src_maxburst = 4;
969 tup->rx_dma_chan = dma_chan;
970 tup->rx_dma_buf_virt = dma_buf;
971 tup->rx_dma_buf_phys = dma_phys;
972 } else {
973 dma_phys = dma_map_single(tup->uport.dev,
974 tup->uport.state->xmit.buf, UART_XMIT_SIZE,
975 DMA_TO_DEVICE);
976 if (dma_mapping_error(tup->uport.dev, dma_phys)) {
977 dev_err(tup->uport.dev, "dma_map_single tx failed\n");
978 dma_release_channel(dma_chan);
979 return -ENOMEM;
980 }
981 dma_buf = tup->uport.state->xmit.buf;
982 dma_sconfig.dst_addr = tup->uport.mapbase;
983 dma_sconfig.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
984 dma_sconfig.dst_maxburst = 16;
985 tup->tx_dma_chan = dma_chan;
986 tup->tx_dma_buf_virt = dma_buf;
987 tup->tx_dma_buf_phys = dma_phys;
988 }
989
990 ret = dmaengine_slave_config(dma_chan, &dma_sconfig);
991 if (ret < 0) {
992 dev_err(tup->uport.dev,
993 "Dma slave config failed, err = %d\n", ret);
994 tegra_uart_dma_channel_free(tup, dma_to_memory);
995 return ret;
996 }
997
998 return 0;
999 }
1000
1001 static int tegra_uart_startup(struct uart_port *u)
1002 {
1003 struct tegra_uart_port *tup = to_tegra_uport(u);
1004 int ret;
1005
1006 ret = tegra_uart_dma_channel_allocate(tup, false);
1007 if (ret < 0) {
1008 dev_err(u->dev, "Tx Dma allocation failed, err = %d\n", ret);
1009 return ret;
1010 }
1011
1012 ret = tegra_uart_dma_channel_allocate(tup, true);
1013 if (ret < 0) {
1014 dev_err(u->dev, "Rx Dma allocation failed, err = %d\n", ret);
1015 goto fail_rx_dma;
1016 }
1017
1018 ret = tegra_uart_hw_init(tup);
1019 if (ret < 0) {
1020 dev_err(u->dev, "Uart HW init failed, err = %d\n", ret);
1021 goto fail_hw_init;
1022 }
1023
1024 ret = request_irq(u->irq, tegra_uart_isr, 0,
1025 dev_name(u->dev), tup);
1026 if (ret < 0) {
1027 dev_err(u->dev, "Failed to register ISR for IRQ %d\n", u->irq);
1028 goto fail_hw_init;
1029 }
1030 return 0;
1031
1032 fail_hw_init:
1033 tegra_uart_dma_channel_free(tup, true);
1034 fail_rx_dma:
1035 tegra_uart_dma_channel_free(tup, false);
1036 return ret;
1037 }
1038
1039 /*
1040 * Flush any TX data submitted for DMA and PIO. Called when the
1041 * TX circular buffer is reset.
1042 */
1043 static void tegra_uart_flush_buffer(struct uart_port *u)
1044 {
1045 struct tegra_uart_port *tup = to_tegra_uport(u);
1046
1047 tup->tx_bytes = 0;
1048 if (tup->tx_dma_chan)
1049 dmaengine_terminate_all(tup->tx_dma_chan);
1050 }
1051
1052 static void tegra_uart_shutdown(struct uart_port *u)
1053 {
1054 struct tegra_uart_port *tup = to_tegra_uport(u);
1055
1056 tegra_uart_hw_deinit(tup);
1057
1058 tup->rx_in_progress = 0;
1059 tup->tx_in_progress = 0;
1060
1061 tegra_uart_dma_channel_free(tup, true);
1062 tegra_uart_dma_channel_free(tup, false);
1063 free_irq(u->irq, tup);
1064 }
1065
1066 static void tegra_uart_enable_ms(struct uart_port *u)
1067 {
1068 struct tegra_uart_port *tup = to_tegra_uport(u);
1069
1070 if (tup->enable_modem_interrupt) {
1071 tup->ier_shadow |= UART_IER_MSI;
1072 tegra_uart_write(tup, tup->ier_shadow, UART_IER);
1073 }
1074 }
1075
1076 static void tegra_uart_set_termios(struct uart_port *u,
1077 struct ktermios *termios, struct ktermios *oldtermios)
1078 {
1079 struct tegra_uart_port *tup = to_tegra_uport(u);
1080 unsigned int baud;
1081 unsigned long flags;
1082 unsigned int lcr;
1083 int symb_bit = 1;
1084 struct clk *parent_clk = clk_get_parent(tup->uart_clk);
1085 unsigned long parent_clk_rate = clk_get_rate(parent_clk);
1086 int max_divider = (tup->cdata->support_clk_src_div) ? 0x7FFF : 0xFFFF;
1087
1088 max_divider *= 16;
1089 spin_lock_irqsave(&u->lock, flags);
1090
1091 /* Changing configuration, it is safe to stop any rx now */
1092 if (tup->rts_active)
1093 set_rts(tup, false);
1094
1095 /* Clear all interrupts as configuration is going to be change */
1096 tegra_uart_write(tup, tup->ier_shadow | UART_IER_RDI, UART_IER);
1097 tegra_uart_read(tup, UART_IER);
1098 tegra_uart_write(tup, 0, UART_IER);
1099 tegra_uart_read(tup, UART_IER);
1100
1101 /* Parity */
1102 lcr = tup->lcr_shadow;
1103 lcr &= ~UART_LCR_PARITY;
1104
1105 /* CMSPAR isn't supported by this driver */
1106 termios->c_cflag &= ~CMSPAR;
1107
1108 if ((termios->c_cflag & PARENB) == PARENB) {
1109 symb_bit++;
1110 if (termios->c_cflag & PARODD) {
1111 lcr |= UART_LCR_PARITY;
1112 lcr &= ~UART_LCR_EPAR;
1113 lcr &= ~UART_LCR_SPAR;
1114 } else {
1115 lcr |= UART_LCR_PARITY;
1116 lcr |= UART_LCR_EPAR;
1117 lcr &= ~UART_LCR_SPAR;
1118 }
1119 }
1120
1121 lcr &= ~UART_LCR_WLEN8;
1122 switch (termios->c_cflag & CSIZE) {
1123 case CS5:
1124 lcr |= UART_LCR_WLEN5;
1125 symb_bit += 5;
1126 break;
1127 case CS6:
1128 lcr |= UART_LCR_WLEN6;
1129 symb_bit += 6;
1130 break;
1131 case CS7:
1132 lcr |= UART_LCR_WLEN7;
1133 symb_bit += 7;
1134 break;
1135 default:
1136 lcr |= UART_LCR_WLEN8;
1137 symb_bit += 8;
1138 break;
1139 }
1140
1141 /* Stop bits */
1142 if (termios->c_cflag & CSTOPB) {
1143 lcr |= UART_LCR_STOP;
1144 symb_bit += 2;
1145 } else {
1146 lcr &= ~UART_LCR_STOP;
1147 symb_bit++;
1148 }
1149
1150 tegra_uart_write(tup, lcr, UART_LCR);
1151 tup->lcr_shadow = lcr;
1152 tup->symb_bit = symb_bit;
1153
1154 /* Baud rate. */
1155 baud = uart_get_baud_rate(u, termios, oldtermios,
1156 parent_clk_rate/max_divider,
1157 parent_clk_rate/16);
1158 spin_unlock_irqrestore(&u->lock, flags);
1159 tegra_set_baudrate(tup, baud);
1160 if (tty_termios_baud_rate(termios))
1161 tty_termios_encode_baud_rate(termios, baud, baud);
1162 spin_lock_irqsave(&u->lock, flags);
1163
1164 /* Flow control */
1165 if (termios->c_cflag & CRTSCTS) {
1166 tup->mcr_shadow |= TEGRA_UART_MCR_CTS_EN;
1167 tup->mcr_shadow &= ~TEGRA_UART_MCR_RTS_EN;
1168 tegra_uart_write(tup, tup->mcr_shadow, UART_MCR);
1169 /* if top layer has asked to set rts active then do so here */
1170 if (tup->rts_active)
1171 set_rts(tup, true);
1172 } else {
1173 tup->mcr_shadow &= ~TEGRA_UART_MCR_CTS_EN;
1174 tup->mcr_shadow &= ~TEGRA_UART_MCR_RTS_EN;
1175 tegra_uart_write(tup, tup->mcr_shadow, UART_MCR);
1176 }
1177
1178 /* update the port timeout based on new settings */
1179 uart_update_timeout(u, termios->c_cflag, baud);
1180
1181 /* Make sure all write has completed */
1182 tegra_uart_read(tup, UART_IER);
1183
1184 /* Reenable interrupt */
1185 tegra_uart_write(tup, tup->ier_shadow, UART_IER);
1186 tegra_uart_read(tup, UART_IER);
1187
1188 spin_unlock_irqrestore(&u->lock, flags);
1189 }
1190
1191 static const char *tegra_uart_type(struct uart_port *u)
1192 {
1193 return TEGRA_UART_TYPE;
1194 }
1195
1196 static struct uart_ops tegra_uart_ops = {
1197 .tx_empty = tegra_uart_tx_empty,
1198 .set_mctrl = tegra_uart_set_mctrl,
1199 .get_mctrl = tegra_uart_get_mctrl,
1200 .stop_tx = tegra_uart_stop_tx,
1201 .start_tx = tegra_uart_start_tx,
1202 .stop_rx = tegra_uart_stop_rx,
1203 .flush_buffer = tegra_uart_flush_buffer,
1204 .enable_ms = tegra_uart_enable_ms,
1205 .break_ctl = tegra_uart_break_ctl,
1206 .startup = tegra_uart_startup,
1207 .shutdown = tegra_uart_shutdown,
1208 .set_termios = tegra_uart_set_termios,
1209 .type = tegra_uart_type,
1210 .request_port = tegra_uart_request_port,
1211 .release_port = tegra_uart_release_port,
1212 };
1213
1214 static struct uart_driver tegra_uart_driver = {
1215 .owner = THIS_MODULE,
1216 .driver_name = "tegra_hsuart",
1217 .dev_name = "ttyTHS",
1218 .cons = NULL,
1219 .nr = TEGRA_UART_MAXIMUM,
1220 };
1221
1222 static int tegra_uart_parse_dt(struct platform_device *pdev,
1223 struct tegra_uart_port *tup)
1224 {
1225 struct device_node *np = pdev->dev.of_node;
1226 int port;
1227
1228 port = of_alias_get_id(np, "serial");
1229 if (port < 0) {
1230 dev_err(&pdev->dev, "failed to get alias id, errno %d\n", port);
1231 return port;
1232 }
1233 tup->uport.line = port;
1234
1235 tup->enable_modem_interrupt = of_property_read_bool(np,
1236 "nvidia,enable-modem-interrupt");
1237 return 0;
1238 }
1239
1240 static struct tegra_uart_chip_data tegra20_uart_chip_data = {
1241 .tx_fifo_full_status = false,
1242 .allow_txfifo_reset_fifo_mode = true,
1243 .support_clk_src_div = false,
1244 };
1245
1246 static struct tegra_uart_chip_data tegra30_uart_chip_data = {
1247 .tx_fifo_full_status = true,
1248 .allow_txfifo_reset_fifo_mode = false,
1249 .support_clk_src_div = true,
1250 };
1251
1252 static const struct of_device_id tegra_uart_of_match[] = {
1253 {
1254 .compatible = "nvidia,tegra30-hsuart",
1255 .data = &tegra30_uart_chip_data,
1256 }, {
1257 .compatible = "nvidia,tegra20-hsuart",
1258 .data = &tegra20_uart_chip_data,
1259 }, {
1260 },
1261 };
1262 MODULE_DEVICE_TABLE(of, tegra_uart_of_match);
1263
1264 static int tegra_uart_probe(struct platform_device *pdev)
1265 {
1266 struct tegra_uart_port *tup;
1267 struct uart_port *u;
1268 struct resource *resource;
1269 int ret;
1270 const struct tegra_uart_chip_data *cdata;
1271 const struct of_device_id *match;
1272
1273 match = of_match_device(tegra_uart_of_match, &pdev->dev);
1274 if (!match) {
1275 dev_err(&pdev->dev, "Error: No device match found\n");
1276 return -ENODEV;
1277 }
1278 cdata = match->data;
1279
1280 tup = devm_kzalloc(&pdev->dev, sizeof(*tup), GFP_KERNEL);
1281 if (!tup) {
1282 dev_err(&pdev->dev, "Failed to allocate memory for tup\n");
1283 return -ENOMEM;
1284 }
1285
1286 ret = tegra_uart_parse_dt(pdev, tup);
1287 if (ret < 0)
1288 return ret;
1289
1290 u = &tup->uport;
1291 u->dev = &pdev->dev;
1292 u->ops = &tegra_uart_ops;
1293 u->type = PORT_TEGRA;
1294 u->fifosize = 32;
1295 tup->cdata = cdata;
1296
1297 platform_set_drvdata(pdev, tup);
1298 resource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1299 if (!resource) {
1300 dev_err(&pdev->dev, "No IO memory resource\n");
1301 return -ENODEV;
1302 }
1303
1304 u->mapbase = resource->start;
1305 u->membase = devm_ioremap_resource(&pdev->dev, resource);
1306 if (IS_ERR(u->membase))
1307 return PTR_ERR(u->membase);
1308
1309 tup->uart_clk = devm_clk_get(&pdev->dev, NULL);
1310 if (IS_ERR(tup->uart_clk)) {
1311 dev_err(&pdev->dev, "Couldn't get the clock\n");
1312 return PTR_ERR(tup->uart_clk);
1313 }
1314
1315 tup->rst = devm_reset_control_get(&pdev->dev, "serial");
1316 if (IS_ERR(tup->rst)) {
1317 dev_err(&pdev->dev, "Couldn't get the reset\n");
1318 return PTR_ERR(tup->rst);
1319 }
1320
1321 u->iotype = UPIO_MEM32;
1322 u->irq = platform_get_irq(pdev, 0);
1323 u->regshift = 2;
1324 ret = uart_add_one_port(&tegra_uart_driver, u);
1325 if (ret < 0) {
1326 dev_err(&pdev->dev, "Failed to add uart port, err %d\n", ret);
1327 return ret;
1328 }
1329 return ret;
1330 }
1331
1332 static int tegra_uart_remove(struct platform_device *pdev)
1333 {
1334 struct tegra_uart_port *tup = platform_get_drvdata(pdev);
1335 struct uart_port *u = &tup->uport;
1336
1337 uart_remove_one_port(&tegra_uart_driver, u);
1338 return 0;
1339 }
1340
1341 #ifdef CONFIG_PM_SLEEP
1342 static int tegra_uart_suspend(struct device *dev)
1343 {
1344 struct tegra_uart_port *tup = dev_get_drvdata(dev);
1345 struct uart_port *u = &tup->uport;
1346
1347 return uart_suspend_port(&tegra_uart_driver, u);
1348 }
1349
1350 static int tegra_uart_resume(struct device *dev)
1351 {
1352 struct tegra_uart_port *tup = dev_get_drvdata(dev);
1353 struct uart_port *u = &tup->uport;
1354
1355 return uart_resume_port(&tegra_uart_driver, u);
1356 }
1357 #endif
1358
1359 static const struct dev_pm_ops tegra_uart_pm_ops = {
1360 SET_SYSTEM_SLEEP_PM_OPS(tegra_uart_suspend, tegra_uart_resume)
1361 };
1362
1363 static struct platform_driver tegra_uart_platform_driver = {
1364 .probe = tegra_uart_probe,
1365 .remove = tegra_uart_remove,
1366 .driver = {
1367 .name = "serial-tegra",
1368 .of_match_table = tegra_uart_of_match,
1369 .pm = &tegra_uart_pm_ops,
1370 },
1371 };
1372
1373 static int __init tegra_uart_init(void)
1374 {
1375 int ret;
1376
1377 ret = uart_register_driver(&tegra_uart_driver);
1378 if (ret < 0) {
1379 pr_err("Could not register %s driver\n",
1380 tegra_uart_driver.driver_name);
1381 return ret;
1382 }
1383
1384 ret = platform_driver_register(&tegra_uart_platform_driver);
1385 if (ret < 0) {
1386 pr_err("Uart platform driver register failed, e = %d\n", ret);
1387 uart_unregister_driver(&tegra_uart_driver);
1388 return ret;
1389 }
1390 return 0;
1391 }
1392
1393 static void __exit tegra_uart_exit(void)
1394 {
1395 pr_info("Unloading tegra uart driver\n");
1396 platform_driver_unregister(&tegra_uart_platform_driver);
1397 uart_unregister_driver(&tegra_uart_driver);
1398 }
1399
1400 module_init(tegra_uart_init);
1401 module_exit(tegra_uart_exit);
1402
1403 MODULE_ALIAS("platform:serial-tegra");
1404 MODULE_DESCRIPTION("High speed UART driver for tegra chipset");
1405 MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
1406 MODULE_LICENSE("GPL v2");
Linux with added FPC-III support