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TTY: serial, handle platform_get_irq retval properly
[linux-2.6/btrfs-unstable.git] / drivers / tty / serial / serial-tegra.c
blob731ac35acb3125a2dcee3a6dbeaee93fb2963de2
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 int dtr_enable;
210
211 tup->rts_active = !!(mctrl & TIOCM_RTS);
212 set_rts(tup, tup->rts_active);
213
214 dtr_enable = !!(mctrl & TIOCM_DTR);
215 set_dtr(tup, dtr_enable);
216 }
217
218 static void tegra_uart_break_ctl(struct uart_port *u, int break_ctl)
219 {
220 struct tegra_uart_port *tup = to_tegra_uport(u);
221 unsigned long lcr;
222
223 lcr = tup->lcr_shadow;
224 if (break_ctl)
225 lcr |= UART_LCR_SBC;
226 else
227 lcr &= ~UART_LCR_SBC;
228 tegra_uart_write(tup, lcr, UART_LCR);
229 tup->lcr_shadow = lcr;
230 }
231
232 /**
233 * tegra_uart_wait_cycle_time: Wait for N UART clock periods
234 *
235 * @tup: Tegra serial port data structure.
236 * @cycles: Number of clock periods to wait.
237 *
238 * Tegra UARTs are clocked at 16X the baud/bit rate and hence the UART
239 * clock speed is 16X the current baud rate.
240 */
241 static void tegra_uart_wait_cycle_time(struct tegra_uart_port *tup,
242 unsigned int cycles)
243 {
244 if (tup->current_baud)
245 udelay(DIV_ROUND_UP(cycles * 1000000, tup->current_baud * 16));
246 }
247
248 /* Wait for a symbol-time. */
249 static void tegra_uart_wait_sym_time(struct tegra_uart_port *tup,
250 unsigned int syms)
251 {
252 if (tup->current_baud)
253 udelay(DIV_ROUND_UP(syms * tup->symb_bit * 1000000,
254 tup->current_baud));
255 }
256
257 static void tegra_uart_fifo_reset(struct tegra_uart_port *tup, u8 fcr_bits)
258 {
259 unsigned long fcr = tup->fcr_shadow;
260
261 if (tup->cdata->allow_txfifo_reset_fifo_mode) {
262 fcr |= fcr_bits & (UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
263 tegra_uart_write(tup, fcr, UART_FCR);
264 } else {
265 fcr &= ~UART_FCR_ENABLE_FIFO;
266 tegra_uart_write(tup, fcr, UART_FCR);
267 udelay(60);
268 fcr |= fcr_bits & (UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
269 tegra_uart_write(tup, fcr, UART_FCR);
270 fcr |= UART_FCR_ENABLE_FIFO;
271 tegra_uart_write(tup, fcr, UART_FCR);
272 }
273
274 /* Dummy read to ensure the write is posted */
275 tegra_uart_read(tup, UART_SCR);
276
277 /*
278 * For all tegra devices (up to t210), there is a hardware issue that
279 * requires software to wait for 32 UART clock periods for the flush
280 * to propagate, otherwise data could be lost.
281 */
282 tegra_uart_wait_cycle_time(tup, 32);
283 }
284
285 static int tegra_set_baudrate(struct tegra_uart_port *tup, unsigned int baud)
286 {
287 unsigned long rate;
288 unsigned int divisor;
289 unsigned long lcr;
290 int ret;
291
292 if (tup->current_baud == baud)
293 return 0;
294
295 if (tup->cdata->support_clk_src_div) {
296 rate = baud * 16;
297 ret = clk_set_rate(tup->uart_clk, rate);
298 if (ret < 0) {
299 dev_err(tup->uport.dev,
300 "clk_set_rate() failed for rate %lu\n", rate);
301 return ret;
302 }
303 divisor = 1;
304 } else {
305 rate = clk_get_rate(tup->uart_clk);
306 divisor = DIV_ROUND_CLOSEST(rate, baud * 16);
307 }
308
309 lcr = tup->lcr_shadow;
310 lcr |= UART_LCR_DLAB;
311 tegra_uart_write(tup, lcr, UART_LCR);
312
313 tegra_uart_write(tup, divisor & 0xFF, UART_TX);
314 tegra_uart_write(tup, ((divisor >> 8) & 0xFF), UART_IER);
315
316 lcr &= ~UART_LCR_DLAB;
317 tegra_uart_write(tup, lcr, UART_LCR);
318
319 /* Dummy read to ensure the write is posted */
320 tegra_uart_read(tup, UART_SCR);
321
322 tup->current_baud = baud;
323
324 /* wait two character intervals at new rate */
325 tegra_uart_wait_sym_time(tup, 2);
326 return 0;
327 }
328
329 static char tegra_uart_decode_rx_error(struct tegra_uart_port *tup,
330 unsigned long lsr)
331 {
332 char flag = TTY_NORMAL;
333
334 if (unlikely(lsr & TEGRA_UART_LSR_ANY)) {
335 if (lsr & UART_LSR_OE) {
336 /* Overrrun error */
337 flag = TTY_OVERRUN;
338 tup->uport.icount.overrun++;
339 dev_err(tup->uport.dev, "Got overrun errors\n");
340 } else if (lsr & UART_LSR_PE) {
341 /* Parity error */
342 flag = TTY_PARITY;
343 tup->uport.icount.parity++;
344 dev_err(tup->uport.dev, "Got Parity errors\n");
345 } else if (lsr & UART_LSR_FE) {
346 flag = TTY_FRAME;
347 tup->uport.icount.frame++;
348 dev_err(tup->uport.dev, "Got frame errors\n");
349 } else if (lsr & UART_LSR_BI) {
350 dev_err(tup->uport.dev, "Got Break\n");
351 tup->uport.icount.brk++;
352 /* If FIFO read error without any data, reset Rx FIFO */
353 if (!(lsr & UART_LSR_DR) && (lsr & UART_LSR_FIFOE))
354 tegra_uart_fifo_reset(tup, UART_FCR_CLEAR_RCVR);
355 }
356 }
357 return flag;
358 }
359
360 static int tegra_uart_request_port(struct uart_port *u)
361 {
362 return 0;
363 }
364
365 static void tegra_uart_release_port(struct uart_port *u)
366 {
367 /* Nothing to do here */
368 }
369
370 static void tegra_uart_fill_tx_fifo(struct tegra_uart_port *tup, int max_bytes)
371 {
372 struct circ_buf *xmit = &tup->uport.state->xmit;
373 int i;
374
375 for (i = 0; i < max_bytes; i++) {
376 BUG_ON(uart_circ_empty(xmit));
377 if (tup->cdata->tx_fifo_full_status) {
378 unsigned long lsr = tegra_uart_read(tup, UART_LSR);
379 if ((lsr & TEGRA_UART_LSR_TXFIFO_FULL))
380 break;
381 }
382 tegra_uart_write(tup, xmit->buf[xmit->tail], UART_TX);
383 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
384 tup->uport.icount.tx++;
385 }
386 }
387
388 static void tegra_uart_start_pio_tx(struct tegra_uart_port *tup,
389 unsigned int bytes)
390 {
391 if (bytes > TEGRA_UART_MIN_DMA)
392 bytes = TEGRA_UART_MIN_DMA;
393
394 tup->tx_in_progress = TEGRA_UART_TX_PIO;
395 tup->tx_bytes = bytes;
396 tup->ier_shadow |= UART_IER_THRI;
397 tegra_uart_write(tup, tup->ier_shadow, UART_IER);
398 }
399
400 static void tegra_uart_tx_dma_complete(void *args)
401 {
402 struct tegra_uart_port *tup = args;
403 struct circ_buf *xmit = &tup->uport.state->xmit;
404 struct dma_tx_state state;
405 unsigned long flags;
406 unsigned int count;
407
408 dmaengine_tx_status(tup->tx_dma_chan, tup->tx_cookie, &state);
409 count = tup->tx_bytes_requested - state.residue;
410 async_tx_ack(tup->tx_dma_desc);
411 spin_lock_irqsave(&tup->uport.lock, flags);
412 xmit->tail = (xmit->tail + count) & (UART_XMIT_SIZE - 1);
413 tup->tx_in_progress = 0;
414 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
415 uart_write_wakeup(&tup->uport);
416 tegra_uart_start_next_tx(tup);
417 spin_unlock_irqrestore(&tup->uport.lock, flags);
418 }
419
420 static int tegra_uart_start_tx_dma(struct tegra_uart_port *tup,
421 unsigned long count)
422 {
423 struct circ_buf *xmit = &tup->uport.state->xmit;
424 dma_addr_t tx_phys_addr;
425
426 dma_sync_single_for_device(tup->uport.dev, tup->tx_dma_buf_phys,
427 UART_XMIT_SIZE, DMA_TO_DEVICE);
428
429 tup->tx_bytes = count & ~(0xF);
430 tx_phys_addr = tup->tx_dma_buf_phys + xmit->tail;
431 tup->tx_dma_desc = dmaengine_prep_slave_single(tup->tx_dma_chan,
432 tx_phys_addr, tup->tx_bytes, DMA_MEM_TO_DEV,
433 DMA_PREP_INTERRUPT);
434 if (!tup->tx_dma_desc) {
435 dev_err(tup->uport.dev, "Not able to get desc for Tx\n");
436 return -EIO;
437 }
438
439 tup->tx_dma_desc->callback = tegra_uart_tx_dma_complete;
440 tup->tx_dma_desc->callback_param = tup;
441 tup->tx_in_progress = TEGRA_UART_TX_DMA;
442 tup->tx_bytes_requested = tup->tx_bytes;
443 tup->tx_cookie = dmaengine_submit(tup->tx_dma_desc);
444 dma_async_issue_pending(tup->tx_dma_chan);
445 return 0;
446 }
447
448 static void tegra_uart_start_next_tx(struct tegra_uart_port *tup)
449 {
450 unsigned long tail;
451 unsigned long count;
452 struct circ_buf *xmit = &tup->uport.state->xmit;
453
454 tail = (unsigned long)&xmit->buf[xmit->tail];
455 count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
456 if (!count)
457 return;
458
459 if (count < TEGRA_UART_MIN_DMA)
460 tegra_uart_start_pio_tx(tup, count);
461 else if (BYTES_TO_ALIGN(tail) > 0)
462 tegra_uart_start_pio_tx(tup, BYTES_TO_ALIGN(tail));
463 else
464 tegra_uart_start_tx_dma(tup, count);
465 }
466
467 /* Called by serial core driver with u->lock taken. */
468 static void tegra_uart_start_tx(struct uart_port *u)
469 {
470 struct tegra_uart_port *tup = to_tegra_uport(u);
471 struct circ_buf *xmit = &u->state->xmit;
472
473 if (!uart_circ_empty(xmit) && !tup->tx_in_progress)
474 tegra_uart_start_next_tx(tup);
475 }
476
477 static unsigned int tegra_uart_tx_empty(struct uart_port *u)
478 {
479 struct tegra_uart_port *tup = to_tegra_uport(u);
480 unsigned int ret = 0;
481 unsigned long flags;
482
483 spin_lock_irqsave(&u->lock, flags);
484 if (!tup->tx_in_progress) {
485 unsigned long lsr = tegra_uart_read(tup, UART_LSR);
486 if ((lsr & TX_EMPTY_STATUS) == TX_EMPTY_STATUS)
487 ret = TIOCSER_TEMT;
488 }
489 spin_unlock_irqrestore(&u->lock, flags);
490 return ret;
491 }
492
493 static void tegra_uart_stop_tx(struct uart_port *u)
494 {
495 struct tegra_uart_port *tup = to_tegra_uport(u);
496 struct circ_buf *xmit = &tup->uport.state->xmit;
497 struct dma_tx_state state;
498 unsigned int count;
499
500 if (tup->tx_in_progress != TEGRA_UART_TX_DMA)
501 return;
502
503 dmaengine_terminate_all(tup->tx_dma_chan);
504 dmaengine_tx_status(tup->tx_dma_chan, tup->tx_cookie, &state);
505 count = tup->tx_bytes_requested - state.residue;
506 async_tx_ack(tup->tx_dma_desc);
507 xmit->tail = (xmit->tail + count) & (UART_XMIT_SIZE - 1);
508 tup->tx_in_progress = 0;
509 }
510
511 static void tegra_uart_handle_tx_pio(struct tegra_uart_port *tup)
512 {
513 struct circ_buf *xmit = &tup->uport.state->xmit;
514
515 tegra_uart_fill_tx_fifo(tup, tup->tx_bytes);
516 tup->tx_in_progress = 0;
517 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
518 uart_write_wakeup(&tup->uport);
519 tegra_uart_start_next_tx(tup);
520 }
521
522 static void tegra_uart_handle_rx_pio(struct tegra_uart_port *tup,
523 struct tty_port *tty)
524 {
525 do {
526 char flag = TTY_NORMAL;
527 unsigned long lsr = 0;
528 unsigned char ch;
529
530 lsr = tegra_uart_read(tup, UART_LSR);
531 if (!(lsr & UART_LSR_DR))
532 break;
533
534 flag = tegra_uart_decode_rx_error(tup, lsr);
535 ch = (unsigned char) tegra_uart_read(tup, UART_RX);
536 tup->uport.icount.rx++;
537
538 if (!uart_handle_sysrq_char(&tup->uport, ch) && tty)
539 tty_insert_flip_char(tty, ch, flag);
540 } while (1);
541 }
542
543 static void tegra_uart_copy_rx_to_tty(struct tegra_uart_port *tup,
544 struct tty_port *tty,
545 unsigned int count)
546 {
547 int copied;
548
549 /* If count is zero, then there is no data to be copied */
550 if (!count)
551 return;
552
553 tup->uport.icount.rx += count;
554 if (!tty) {
555 dev_err(tup->uport.dev, "No tty port\n");
556 return;
557 }
558 dma_sync_single_for_cpu(tup->uport.dev, tup->rx_dma_buf_phys,
559 TEGRA_UART_RX_DMA_BUFFER_SIZE, DMA_FROM_DEVICE);
560 copied = tty_insert_flip_string(tty,
561 ((unsigned char *)(tup->rx_dma_buf_virt)), count);
562 if (copied != count) {
563 WARN_ON(1);
564 dev_err(tup->uport.dev, "RxData copy to tty layer failed\n");
565 }
566 dma_sync_single_for_device(tup->uport.dev, tup->rx_dma_buf_phys,
567 TEGRA_UART_RX_DMA_BUFFER_SIZE, DMA_TO_DEVICE);
568 }
569
570 static void tegra_uart_rx_buffer_push(struct tegra_uart_port *tup,
571 unsigned int residue)
572 {
573 struct tty_port *port = &tup->uport.state->port;
574 struct tty_struct *tty = tty_port_tty_get(port);
575 unsigned int count;
576
577 async_tx_ack(tup->rx_dma_desc);
578 count = tup->rx_bytes_requested - residue;
579
580 /* If we are here, DMA is stopped */
581 tegra_uart_copy_rx_to_tty(tup, port, count);
582
583 tegra_uart_handle_rx_pio(tup, port);
584 if (tty) {
585 tty_flip_buffer_push(port);
586 tty_kref_put(tty);
587 }
588 }
589
590 static void tegra_uart_rx_dma_complete(void *args)
591 {
592 struct tegra_uart_port *tup = args;
593 struct uart_port *u = &tup->uport;
594 unsigned long flags;
595 struct dma_tx_state state;
596 enum dma_status status;
597
598 spin_lock_irqsave(&u->lock, flags);
599
600 status = dmaengine_tx_status(tup->rx_dma_chan, tup->rx_cookie, &state);
601
602 if (status == DMA_IN_PROGRESS) {
603 dev_dbg(tup->uport.dev, "RX DMA is in progress\n");
604 goto done;
605 }
606
607 /* Deactivate flow control to stop sender */
608 if (tup->rts_active)
609 set_rts(tup, false);
610
611 tegra_uart_rx_buffer_push(tup, 0);
612 tegra_uart_start_rx_dma(tup);
613
614 /* Activate flow control to start transfer */
615 if (tup->rts_active)
616 set_rts(tup, true);
617
618 done:
619 spin_unlock_irqrestore(&u->lock, flags);
620 }
621
622 static void tegra_uart_handle_rx_dma(struct tegra_uart_port *tup)
623 {
624 struct dma_tx_state state;
625
626 /* Deactivate flow control to stop sender */
627 if (tup->rts_active)
628 set_rts(tup, false);
629
630 dmaengine_terminate_all(tup->rx_dma_chan);
631 dmaengine_tx_status(tup->rx_dma_chan, tup->rx_cookie, &state);
632 tegra_uart_rx_buffer_push(tup, state.residue);
633 tegra_uart_start_rx_dma(tup);
634
635 if (tup->rts_active)
636 set_rts(tup, true);
637 }
638
639 static int tegra_uart_start_rx_dma(struct tegra_uart_port *tup)
640 {
641 unsigned int count = TEGRA_UART_RX_DMA_BUFFER_SIZE;
642
643 tup->rx_dma_desc = dmaengine_prep_slave_single(tup->rx_dma_chan,
644 tup->rx_dma_buf_phys, count, DMA_DEV_TO_MEM,
645 DMA_PREP_INTERRUPT);
646 if (!tup->rx_dma_desc) {
647 dev_err(tup->uport.dev, "Not able to get desc for Rx\n");
648 return -EIO;
649 }
650
651 tup->rx_dma_desc->callback = tegra_uart_rx_dma_complete;
652 tup->rx_dma_desc->callback_param = tup;
653 dma_sync_single_for_device(tup->uport.dev, tup->rx_dma_buf_phys,
654 count, DMA_TO_DEVICE);
655 tup->rx_bytes_requested = count;
656 tup->rx_cookie = dmaengine_submit(tup->rx_dma_desc);
657 dma_async_issue_pending(tup->rx_dma_chan);
658 return 0;
659 }
660
661 static void tegra_uart_handle_modem_signal_change(struct uart_port *u)
662 {
663 struct tegra_uart_port *tup = to_tegra_uport(u);
664 unsigned long msr;
665
666 msr = tegra_uart_read(tup, UART_MSR);
667 if (!(msr & UART_MSR_ANY_DELTA))
668 return;
669
670 if (msr & UART_MSR_TERI)
671 tup->uport.icount.rng++;
672 if (msr & UART_MSR_DDSR)
673 tup->uport.icount.dsr++;
674 /* We may only get DDCD when HW init and reset */
675 if (msr & UART_MSR_DDCD)
676 uart_handle_dcd_change(&tup->uport, msr & UART_MSR_DCD);
677 /* Will start/stop_tx accordingly */
678 if (msr & UART_MSR_DCTS)
679 uart_handle_cts_change(&tup->uport, msr & UART_MSR_CTS);
680 }
681
682 static irqreturn_t tegra_uart_isr(int irq, void *data)
683 {
684 struct tegra_uart_port *tup = data;
685 struct uart_port *u = &tup->uport;
686 unsigned long iir;
687 unsigned long ier;
688 bool is_rx_int = false;
689 unsigned long flags;
690
691 spin_lock_irqsave(&u->lock, flags);
692 while (1) {
693 iir = tegra_uart_read(tup, UART_IIR);
694 if (iir & UART_IIR_NO_INT) {
695 if (is_rx_int) {
696 tegra_uart_handle_rx_dma(tup);
697 if (tup->rx_in_progress) {
698 ier = tup->ier_shadow;
699 ier |= (UART_IER_RLSI | UART_IER_RTOIE |
700 TEGRA_UART_IER_EORD);
701 tup->ier_shadow = ier;
702 tegra_uart_write(tup, ier, UART_IER);
703 }
704 }
705 spin_unlock_irqrestore(&u->lock, flags);
706 return IRQ_HANDLED;
707 }
708
709 switch ((iir >> 1) & 0x7) {
710 case 0: /* Modem signal change interrupt */
711 tegra_uart_handle_modem_signal_change(u);
712 break;
713
714 case 1: /* Transmit interrupt only triggered when using PIO */
715 tup->ier_shadow &= ~UART_IER_THRI;
716 tegra_uart_write(tup, tup->ier_shadow, UART_IER);
717 tegra_uart_handle_tx_pio(tup);
718 break;
719
720 case 4: /* End of data */
721 case 6: /* Rx timeout */
722 case 2: /* Receive */
723 if (!is_rx_int) {
724 is_rx_int = true;
725 /* Disable Rx interrupts */
726 ier = tup->ier_shadow;
727 ier |= UART_IER_RDI;
728 tegra_uart_write(tup, ier, UART_IER);
729 ier &= ~(UART_IER_RDI | UART_IER_RLSI |
730 UART_IER_RTOIE | TEGRA_UART_IER_EORD);
731 tup->ier_shadow = ier;
732 tegra_uart_write(tup, ier, UART_IER);
733 }
734 break;
735
736 case 3: /* Receive error */
737 tegra_uart_decode_rx_error(tup,
738 tegra_uart_read(tup, UART_LSR));
739 break;
740
741 case 5: /* break nothing to handle */
742 case 7: /* break nothing to handle */
743 break;
744 }
745 }
746 }
747
748 static void tegra_uart_stop_rx(struct uart_port *u)
749 {
750 struct tegra_uart_port *tup = to_tegra_uport(u);
751 struct dma_tx_state state;
752 unsigned long ier;
753
754 if (tup->rts_active)
755 set_rts(tup, false);
756
757 if (!tup->rx_in_progress)
758 return;
759
760 tegra_uart_wait_sym_time(tup, 1); /* wait a character interval */
761
762 ier = tup->ier_shadow;
763 ier &= ~(UART_IER_RDI | UART_IER_RLSI | UART_IER_RTOIE |
764 TEGRA_UART_IER_EORD);
765 tup->ier_shadow = ier;
766 tegra_uart_write(tup, ier, UART_IER);
767 tup->rx_in_progress = 0;
768 dmaengine_terminate_all(tup->rx_dma_chan);
769 dmaengine_tx_status(tup->rx_dma_chan, tup->rx_cookie, &state);
770 tegra_uart_rx_buffer_push(tup, state.residue);
771 }
772
773 static void tegra_uart_hw_deinit(struct tegra_uart_port *tup)
774 {
775 unsigned long flags;
776 unsigned long char_time = DIV_ROUND_UP(10000000, tup->current_baud);
777 unsigned long fifo_empty_time = tup->uport.fifosize * char_time;
778 unsigned long wait_time;
779 unsigned long lsr;
780 unsigned long msr;
781 unsigned long mcr;
782
783 /* Disable interrupts */
784 tegra_uart_write(tup, 0, UART_IER);
785
786 lsr = tegra_uart_read(tup, UART_LSR);
787 if ((lsr & UART_LSR_TEMT) != UART_LSR_TEMT) {
788 msr = tegra_uart_read(tup, UART_MSR);
789 mcr = tegra_uart_read(tup, UART_MCR);
790 if ((mcr & TEGRA_UART_MCR_CTS_EN) && (msr & UART_MSR_CTS))
791 dev_err(tup->uport.dev,
792 "Tx Fifo not empty, CTS disabled, waiting\n");
793
794 /* Wait for Tx fifo to be empty */
795 while ((lsr & UART_LSR_TEMT) != UART_LSR_TEMT) {
796 wait_time = min(fifo_empty_time, 100lu);
797 udelay(wait_time);
798 fifo_empty_time -= wait_time;
799 if (!fifo_empty_time) {
800 msr = tegra_uart_read(tup, UART_MSR);
801 mcr = tegra_uart_read(tup, UART_MCR);
802 if ((mcr & TEGRA_UART_MCR_CTS_EN) &&
803 (msr & UART_MSR_CTS))
804 dev_err(tup->uport.dev,
805 "Slave not ready\n");
806 break;
807 }
808 lsr = tegra_uart_read(tup, UART_LSR);
809 }
810 }
811
812 spin_lock_irqsave(&tup->uport.lock, flags);
813 /* Reset the Rx and Tx FIFOs */
814 tegra_uart_fifo_reset(tup, UART_FCR_CLEAR_XMIT | UART_FCR_CLEAR_RCVR);
815 tup->current_baud = 0;
816 spin_unlock_irqrestore(&tup->uport.lock, flags);
817
818 clk_disable_unprepare(tup->uart_clk);
819 }
820
821 static int tegra_uart_hw_init(struct tegra_uart_port *tup)
822 {
823 int ret;
824
825 tup->fcr_shadow = 0;
826 tup->mcr_shadow = 0;
827 tup->lcr_shadow = 0;
828 tup->ier_shadow = 0;
829 tup->current_baud = 0;
830
831 clk_prepare_enable(tup->uart_clk);
832
833 /* Reset the UART controller to clear all previous status.*/
834 reset_control_assert(tup->rst);
835 udelay(10);
836 reset_control_deassert(tup->rst);
837
838 tup->rx_in_progress = 0;
839 tup->tx_in_progress = 0;
840
841 /*
842 * Set the trigger level
843 *
844 * For PIO mode:
845 *
846 * For receive, this will interrupt the CPU after that many number of
847 * bytes are received, for the remaining bytes the receive timeout
848 * interrupt is received. Rx high watermark is set to 4.
849 *
850 * For transmit, if the trasnmit interrupt is enabled, this will
851 * interrupt the CPU when the number of entries in the FIFO reaches the
852 * low watermark. Tx low watermark is set to 16 bytes.
853 *
854 * For DMA mode:
855 *
856 * Set the Tx trigger to 16. This should match the DMA burst size that
857 * programmed in the DMA registers.
858 */
859 tup->fcr_shadow = UART_FCR_ENABLE_FIFO;
860 tup->fcr_shadow |= UART_FCR_R_TRIG_01;
861 tup->fcr_shadow |= TEGRA_UART_TX_TRIG_16B;
862 tegra_uart_write(tup, tup->fcr_shadow, UART_FCR);
863
864 /* Dummy read to ensure the write is posted */
865 tegra_uart_read(tup, UART_SCR);
866
867 /*
868 * For all tegra devices (up to t210), there is a hardware issue that
869 * requires software to wait for 3 UART clock periods after enabling
870 * the TX fifo, otherwise data could be lost.
871 */
872 tegra_uart_wait_cycle_time(tup, 3);
873
874 /*
875 * Initialize the UART with default configuration
876 * (115200, N, 8, 1) so that the receive DMA buffer may be
877 * enqueued
878 */
879 tup->lcr_shadow = TEGRA_UART_DEFAULT_LSR;
880 tegra_set_baudrate(tup, TEGRA_UART_DEFAULT_BAUD);
881 tup->fcr_shadow |= UART_FCR_DMA_SELECT;
882 tegra_uart_write(tup, tup->fcr_shadow, UART_FCR);
883
884 ret = tegra_uart_start_rx_dma(tup);
885 if (ret < 0) {
886 dev_err(tup->uport.dev, "Not able to start Rx DMA\n");
887 return ret;
888 }
889 tup->rx_in_progress = 1;
890
891 /*
892 * Enable IE_RXS for the receive status interrupts like line errros.
893 * Enable IE_RX_TIMEOUT to get the bytes which cannot be DMA'd.
894 *
895 * If using DMA mode, enable EORD instead of receive interrupt which
896 * will interrupt after the UART is done with the receive instead of
897 * the interrupt when the FIFO "threshold" is reached.
898 *
899 * EORD is different interrupt than RX_TIMEOUT - RX_TIMEOUT occurs when
900 * the DATA is sitting in the FIFO and couldn't be transferred to the
901 * DMA as the DMA size alignment(4 bytes) is not met. EORD will be
902 * triggered when there is a pause of the incomming data stream for 4
903 * characters long.
904 *
905 * For pauses in the data which is not aligned to 4 bytes, we get
906 * both the EORD as well as RX_TIMEOUT - SW sees RX_TIMEOUT first
907 * then the EORD.
908 */
909 tup->ier_shadow = UART_IER_RLSI | UART_IER_RTOIE | TEGRA_UART_IER_EORD;
910 tegra_uart_write(tup, tup->ier_shadow, UART_IER);
911 return 0;
912 }
913
914 static void tegra_uart_dma_channel_free(struct tegra_uart_port *tup,
915 bool dma_to_memory)
916 {
917 if (dma_to_memory) {
918 dmaengine_terminate_all(tup->rx_dma_chan);
919 dma_release_channel(tup->rx_dma_chan);
920 dma_free_coherent(tup->uport.dev, TEGRA_UART_RX_DMA_BUFFER_SIZE,
921 tup->rx_dma_buf_virt, tup->rx_dma_buf_phys);
922 tup->rx_dma_chan = NULL;
923 tup->rx_dma_buf_phys = 0;
924 tup->rx_dma_buf_virt = NULL;
925 } else {
926 dmaengine_terminate_all(tup->tx_dma_chan);
927 dma_release_channel(tup->tx_dma_chan);
928 dma_unmap_single(tup->uport.dev, tup->tx_dma_buf_phys,
929 UART_XMIT_SIZE, DMA_TO_DEVICE);
930 tup->tx_dma_chan = NULL;
931 tup->tx_dma_buf_phys = 0;
932 tup->tx_dma_buf_virt = NULL;
933 }
934 }
935
936 static int tegra_uart_dma_channel_allocate(struct tegra_uart_port *tup,
937 bool dma_to_memory)
938 {
939 struct dma_chan *dma_chan;
940 unsigned char *dma_buf;
941 dma_addr_t dma_phys;
942 int ret;
943 struct dma_slave_config dma_sconfig;
944
945 dma_chan = dma_request_slave_channel_reason(tup->uport.dev,
946 dma_to_memory ? "rx" : "tx");
947 if (IS_ERR(dma_chan)) {
948 ret = PTR_ERR(dma_chan);
949 dev_err(tup->uport.dev,
950 "DMA channel alloc failed: %d\n", ret);
951 return ret;
952 }
953
954 if (dma_to_memory) {
955 dma_buf = dma_alloc_coherent(tup->uport.dev,
956 TEGRA_UART_RX_DMA_BUFFER_SIZE,
957 &dma_phys, GFP_KERNEL);
958 if (!dma_buf) {
959 dev_err(tup->uport.dev,
960 "Not able to allocate the dma buffer\n");
961 dma_release_channel(dma_chan);
962 return -ENOMEM;
963 }
964 dma_sconfig.src_addr = tup->uport.mapbase;
965 dma_sconfig.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
966 dma_sconfig.src_maxburst = 4;
967 tup->rx_dma_chan = dma_chan;
968 tup->rx_dma_buf_virt = dma_buf;
969 tup->rx_dma_buf_phys = dma_phys;
970 } else {
971 dma_phys = dma_map_single(tup->uport.dev,
972 tup->uport.state->xmit.buf, UART_XMIT_SIZE,
973 DMA_TO_DEVICE);
974 if (dma_mapping_error(tup->uport.dev, dma_phys)) {
975 dev_err(tup->uport.dev, "dma_map_single tx failed\n");
976 dma_release_channel(dma_chan);
977 return -ENOMEM;
978 }
979 dma_buf = tup->uport.state->xmit.buf;
980 dma_sconfig.dst_addr = tup->uport.mapbase;
981 dma_sconfig.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
982 dma_sconfig.dst_maxburst = 16;
983 tup->tx_dma_chan = dma_chan;
984 tup->tx_dma_buf_virt = dma_buf;
985 tup->tx_dma_buf_phys = dma_phys;
986 }
987
988 ret = dmaengine_slave_config(dma_chan, &dma_sconfig);
989 if (ret < 0) {
990 dev_err(tup->uport.dev,
991 "Dma slave config failed, err = %d\n", ret);
992 tegra_uart_dma_channel_free(tup, dma_to_memory);
993 return ret;
994 }
995
996 return 0;
997 }
998
999 static int tegra_uart_startup(struct uart_port *u)
1000 {
1001 struct tegra_uart_port *tup = to_tegra_uport(u);
1002 int ret;
1003
1004 ret = tegra_uart_dma_channel_allocate(tup, false);
1005 if (ret < 0) {
1006 dev_err(u->dev, "Tx Dma allocation failed, err = %d\n", ret);
1007 return ret;
1008 }
1009
1010 ret = tegra_uart_dma_channel_allocate(tup, true);
1011 if (ret < 0) {
1012 dev_err(u->dev, "Rx Dma allocation failed, err = %d\n", ret);
1013 goto fail_rx_dma;
1014 }
1015
1016 ret = tegra_uart_hw_init(tup);
1017 if (ret < 0) {
1018 dev_err(u->dev, "Uart HW init failed, err = %d\n", ret);
1019 goto fail_hw_init;
1020 }
1021
1022 ret = request_irq(u->irq, tegra_uart_isr, 0,
1023 dev_name(u->dev), tup);
1024 if (ret < 0) {
1025 dev_err(u->dev, "Failed to register ISR for IRQ %d\n", u->irq);
1026 goto fail_hw_init;
1027 }
1028 return 0;
1029
1030 fail_hw_init:
1031 tegra_uart_dma_channel_free(tup, true);
1032 fail_rx_dma:
1033 tegra_uart_dma_channel_free(tup, false);
1034 return ret;
1035 }
1036
1037 /*
1038 * Flush any TX data submitted for DMA and PIO. Called when the
1039 * TX circular buffer is reset.
1040 */
1041 static void tegra_uart_flush_buffer(struct uart_port *u)
1042 {
1043 struct tegra_uart_port *tup = to_tegra_uport(u);
1044
1045 tup->tx_bytes = 0;
1046 if (tup->tx_dma_chan)
1047 dmaengine_terminate_all(tup->tx_dma_chan);
1048 }
1049
1050 static void tegra_uart_shutdown(struct uart_port *u)
1051 {
1052 struct tegra_uart_port *tup = to_tegra_uport(u);
1053
1054 tegra_uart_hw_deinit(tup);
1055
1056 tup->rx_in_progress = 0;
1057 tup->tx_in_progress = 0;
1058
1059 tegra_uart_dma_channel_free(tup, true);
1060 tegra_uart_dma_channel_free(tup, false);
1061 free_irq(u->irq, tup);
1062 }
1063
1064 static void tegra_uart_enable_ms(struct uart_port *u)
1065 {
1066 struct tegra_uart_port *tup = to_tegra_uport(u);
1067
1068 if (tup->enable_modem_interrupt) {
1069 tup->ier_shadow |= UART_IER_MSI;
1070 tegra_uart_write(tup, tup->ier_shadow, UART_IER);
1071 }
1072 }
1073
1074 static void tegra_uart_set_termios(struct uart_port *u,
1075 struct ktermios *termios, struct ktermios *oldtermios)
1076 {
1077 struct tegra_uart_port *tup = to_tegra_uport(u);
1078 unsigned int baud;
1079 unsigned long flags;
1080 unsigned int lcr;
1081 int symb_bit = 1;
1082 struct clk *parent_clk = clk_get_parent(tup->uart_clk);
1083 unsigned long parent_clk_rate = clk_get_rate(parent_clk);
1084 int max_divider = (tup->cdata->support_clk_src_div) ? 0x7FFF : 0xFFFF;
1085
1086 max_divider *= 16;
1087 spin_lock_irqsave(&u->lock, flags);
1088
1089 /* Changing configuration, it is safe to stop any rx now */
1090 if (tup->rts_active)
1091 set_rts(tup, false);
1092
1093 /* Clear all interrupts as configuration is going to be change */
1094 tegra_uart_write(tup, tup->ier_shadow | UART_IER_RDI, UART_IER);
1095 tegra_uart_read(tup, UART_IER);
1096 tegra_uart_write(tup, 0, UART_IER);
1097 tegra_uart_read(tup, UART_IER);
1098
1099 /* Parity */
1100 lcr = tup->lcr_shadow;
1101 lcr &= ~UART_LCR_PARITY;
1102
1103 /* CMSPAR isn't supported by this driver */
1104 termios->c_cflag &= ~CMSPAR;
1105
1106 if ((termios->c_cflag & PARENB) == PARENB) {
1107 symb_bit++;
1108 if (termios->c_cflag & PARODD) {
1109 lcr |= UART_LCR_PARITY;
1110 lcr &= ~UART_LCR_EPAR;
1111 lcr &= ~UART_LCR_SPAR;
1112 } else {
1113 lcr |= UART_LCR_PARITY;
1114 lcr |= UART_LCR_EPAR;
1115 lcr &= ~UART_LCR_SPAR;
1116 }
1117 }
1118
1119 lcr &= ~UART_LCR_WLEN8;
1120 switch (termios->c_cflag & CSIZE) {
1121 case CS5:
1122 lcr |= UART_LCR_WLEN5;
1123 symb_bit += 5;
1124 break;
1125 case CS6:
1126 lcr |= UART_LCR_WLEN6;
1127 symb_bit += 6;
1128 break;
1129 case CS7:
1130 lcr |= UART_LCR_WLEN7;
1131 symb_bit += 7;
1132 break;
1133 default:
1134 lcr |= UART_LCR_WLEN8;
1135 symb_bit += 8;
1136 break;
1137 }
1138
1139 /* Stop bits */
1140 if (termios->c_cflag & CSTOPB) {
1141 lcr |= UART_LCR_STOP;
1142 symb_bit += 2;
1143 } else {
1144 lcr &= ~UART_LCR_STOP;
1145 symb_bit++;
1146 }
1147
1148 tegra_uart_write(tup, lcr, UART_LCR);
1149 tup->lcr_shadow = lcr;
1150 tup->symb_bit = symb_bit;
1151
1152 /* Baud rate. */
1153 baud = uart_get_baud_rate(u, termios, oldtermios,
1154 parent_clk_rate/max_divider,
1155 parent_clk_rate/16);
1156 spin_unlock_irqrestore(&u->lock, flags);
1157 tegra_set_baudrate(tup, baud);
1158 if (tty_termios_baud_rate(termios))
1159 tty_termios_encode_baud_rate(termios, baud, baud);
1160 spin_lock_irqsave(&u->lock, flags);
1161
1162 /* Flow control */
1163 if (termios->c_cflag & CRTSCTS) {
1164 tup->mcr_shadow |= TEGRA_UART_MCR_CTS_EN;
1165 tup->mcr_shadow &= ~TEGRA_UART_MCR_RTS_EN;
1166 tegra_uart_write(tup, tup->mcr_shadow, UART_MCR);
1167 /* if top layer has asked to set rts active then do so here */
1168 if (tup->rts_active)
1169 set_rts(tup, true);
1170 } else {
1171 tup->mcr_shadow &= ~TEGRA_UART_MCR_CTS_EN;
1172 tup->mcr_shadow &= ~TEGRA_UART_MCR_RTS_EN;
1173 tegra_uart_write(tup, tup->mcr_shadow, UART_MCR);
1174 }
1175
1176 /* update the port timeout based on new settings */
1177 uart_update_timeout(u, termios->c_cflag, baud);
1178
1179 /* Make sure all write has completed */
1180 tegra_uart_read(tup, UART_IER);
1181
1182 /* Reenable interrupt */
1183 tegra_uart_write(tup, tup->ier_shadow, UART_IER);
1184 tegra_uart_read(tup, UART_IER);
1185
1186 spin_unlock_irqrestore(&u->lock, flags);
1187 }
1188
1189 static const char *tegra_uart_type(struct uart_port *u)
1190 {
1191 return TEGRA_UART_TYPE;
1192 }
1193
1194 static struct uart_ops tegra_uart_ops = {
1195 .tx_empty = tegra_uart_tx_empty,
1196 .set_mctrl = tegra_uart_set_mctrl,
1197 .get_mctrl = tegra_uart_get_mctrl,
1198 .stop_tx = tegra_uart_stop_tx,
1199 .start_tx = tegra_uart_start_tx,
1200 .stop_rx = tegra_uart_stop_rx,
1201 .flush_buffer = tegra_uart_flush_buffer,
1202 .enable_ms = tegra_uart_enable_ms,
1203 .break_ctl = tegra_uart_break_ctl,
1204 .startup = tegra_uart_startup,
1205 .shutdown = tegra_uart_shutdown,
1206 .set_termios = tegra_uart_set_termios,
1207 .type = tegra_uart_type,
1208 .request_port = tegra_uart_request_port,
1209 .release_port = tegra_uart_release_port,
1210 };
1211
1212 static struct uart_driver tegra_uart_driver = {
1213 .owner = THIS_MODULE,
1214 .driver_name = "tegra_hsuart",
1215 .dev_name = "ttyTHS",
1216 .cons = NULL,
1217 .nr = TEGRA_UART_MAXIMUM,
1218 };
1219
1220 static int tegra_uart_parse_dt(struct platform_device *pdev,
1221 struct tegra_uart_port *tup)
1222 {
1223 struct device_node *np = pdev->dev.of_node;
1224 int port;
1225
1226 port = of_alias_get_id(np, "serial");
1227 if (port < 0) {
1228 dev_err(&pdev->dev, "failed to get alias id, errno %d\n", port);
1229 return port;
1230 }
1231 tup->uport.line = port;
1232
1233 tup->enable_modem_interrupt = of_property_read_bool(np,
1234 "nvidia,enable-modem-interrupt");
1235 return 0;
1236 }
1237
1238 static struct tegra_uart_chip_data tegra20_uart_chip_data = {
1239 .tx_fifo_full_status = false,
1240 .allow_txfifo_reset_fifo_mode = true,
1241 .support_clk_src_div = false,
1242 };
1243
1244 static struct tegra_uart_chip_data tegra30_uart_chip_data = {
1245 .tx_fifo_full_status = true,
1246 .allow_txfifo_reset_fifo_mode = false,
1247 .support_clk_src_div = true,
1248 };
1249
1250 static const struct of_device_id tegra_uart_of_match[] = {
1251 {
1252 .compatible = "nvidia,tegra30-hsuart",
1253 .data = &tegra30_uart_chip_data,
1254 }, {
1255 .compatible = "nvidia,tegra20-hsuart",
1256 .data = &tegra20_uart_chip_data,
1257 }, {
1258 },
1259 };
1260 MODULE_DEVICE_TABLE(of, tegra_uart_of_match);
1261
1262 static int tegra_uart_probe(struct platform_device *pdev)
1263 {
1264 struct tegra_uart_port *tup;
1265 struct uart_port *u;
1266 struct resource *resource;
1267 int ret;
1268 const struct tegra_uart_chip_data *cdata;
1269 const struct of_device_id *match;
1270
1271 match = of_match_device(tegra_uart_of_match, &pdev->dev);
1272 if (!match) {
1273 dev_err(&pdev->dev, "Error: No device match found\n");
1274 return -ENODEV;
1275 }
1276 cdata = match->data;
1277
1278 tup = devm_kzalloc(&pdev->dev, sizeof(*tup), GFP_KERNEL);
1279 if (!tup) {
1280 dev_err(&pdev->dev, "Failed to allocate memory for tup\n");
1281 return -ENOMEM;
1282 }
1283
1284 ret = tegra_uart_parse_dt(pdev, tup);
1285 if (ret < 0)
1286 return ret;
1287
1288 u = &tup->uport;
1289 u->dev = &pdev->dev;
1290 u->ops = &tegra_uart_ops;
1291 u->type = PORT_TEGRA;
1292 u->fifosize = 32;
1293 tup->cdata = cdata;
1294
1295 platform_set_drvdata(pdev, tup);
1296 resource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1297 if (!resource) {
1298 dev_err(&pdev->dev, "No IO memory resource\n");
1299 return -ENODEV;
1300 }
1301
1302 u->mapbase = resource->start;
1303 u->membase = devm_ioremap_resource(&pdev->dev, resource);
1304 if (IS_ERR(u->membase))
1305 return PTR_ERR(u->membase);
1306
1307 tup->uart_clk = devm_clk_get(&pdev->dev, NULL);
1308 if (IS_ERR(tup->uart_clk)) {
1309 dev_err(&pdev->dev, "Couldn't get the clock\n");
1310 return PTR_ERR(tup->uart_clk);
1311 }
1312
1313 tup->rst = devm_reset_control_get(&pdev->dev, "serial");
1314 if (IS_ERR(tup->rst)) {
1315 dev_err(&pdev->dev, "Couldn't get the reset\n");
1316 return PTR_ERR(tup->rst);
1317 }
1318
1319 u->iotype = UPIO_MEM32;
1320 ret = platform_get_irq(pdev, 0);
1321 if (ret < 0) {
1322 dev_err(&pdev->dev, "Couldn't get IRQ\n");
1323 return ret;
1324 }
1325 u->irq = ret;
1326 u->regshift = 2;
1327 ret = uart_add_one_port(&tegra_uart_driver, u);
1328 if (ret < 0) {
1329 dev_err(&pdev->dev, "Failed to add uart port, err %d\n", ret);
1330 return ret;
1331 }
1332 return ret;
1333 }
1334
1335 static int tegra_uart_remove(struct platform_device *pdev)
1336 {
1337 struct tegra_uart_port *tup = platform_get_drvdata(pdev);
1338 struct uart_port *u = &tup->uport;
1339
1340 uart_remove_one_port(&tegra_uart_driver, u);
1341 return 0;
1342 }
1343
1344 #ifdef CONFIG_PM_SLEEP
1345 static int tegra_uart_suspend(struct device *dev)
1346 {
1347 struct tegra_uart_port *tup = dev_get_drvdata(dev);
1348 struct uart_port *u = &tup->uport;
1349
1350 return uart_suspend_port(&tegra_uart_driver, u);
1351 }
1352
1353 static int tegra_uart_resume(struct device *dev)
1354 {
1355 struct tegra_uart_port *tup = dev_get_drvdata(dev);
1356 struct uart_port *u = &tup->uport;
1357
1358 return uart_resume_port(&tegra_uart_driver, u);
1359 }
1360 #endif
1361
1362 static const struct dev_pm_ops tegra_uart_pm_ops = {
1363 SET_SYSTEM_SLEEP_PM_OPS(tegra_uart_suspend, tegra_uart_resume)
1364 };
1365
1366 static struct platform_driver tegra_uart_platform_driver = {
1367 .probe = tegra_uart_probe,
1368 .remove = tegra_uart_remove,
1369 .driver = {
1370 .name = "serial-tegra",
1371 .of_match_table = tegra_uart_of_match,
1372 .pm = &tegra_uart_pm_ops,
1373 },
1374 };
1375
1376 static int __init tegra_uart_init(void)
1377 {
1378 int ret;
1379
1380 ret = uart_register_driver(&tegra_uart_driver);
1381 if (ret < 0) {
1382 pr_err("Could not register %s driver\n",
1383 tegra_uart_driver.driver_name);
1384 return ret;
1385 }
1386
1387 ret = platform_driver_register(&tegra_uart_platform_driver);
1388 if (ret < 0) {
1389 pr_err("Uart platform driver register failed, e = %d\n", ret);
1390 uart_unregister_driver(&tegra_uart_driver);
1391 return ret;
1392 }
1393 return 0;
1394 }
1395
1396 static void __exit tegra_uart_exit(void)
1397 {
1398 pr_info("Unloading tegra uart driver\n");
1399 platform_driver_unregister(&tegra_uart_platform_driver);
1400 uart_unregister_driver(&tegra_uart_driver);
1401 }
1402
1403 module_init(tegra_uart_init);
1404 module_exit(tegra_uart_exit);
1405
1406 MODULE_ALIAS("platform:serial-tegra");
1407 MODULE_DESCRIPTION("High speed UART driver for tegra chipset");
1408 MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
1409 MODULE_LICENSE("GPL v2");
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