1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
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/serial.h>
38#include <linux/serial_8250.h>
39#include <linux/serial_core.h>
40#include <linux/serial_reg.h>
41#include <linux/slab.h>
42#include <linux/string.h>
43#include <linux/termios.h>
44#include <linux/tty.h>
45#include <linux/tty_flip.h>
46
47#include <linux/clk/tegra.h>
48
49#define TEGRA_UART_TYPE "TEGRA_UART"
50#define TX_EMPTY_STATUS (UART_LSR_TEMT | UART_LSR_THRE)
51#define BYTES_TO_ALIGN(x) ((unsigned long)(x) & 0x3)
52
53#define TEGRA_UART_RX_DMA_BUFFER_SIZE 4096
54#define TEGRA_UART_LSR_TXFIFO_FULL 0x100
55#define TEGRA_UART_IER_EORD 0x20
56#define TEGRA_UART_MCR_RTS_EN 0x40
57#define TEGRA_UART_MCR_CTS_EN 0x20
58#define TEGRA_UART_LSR_ANY (UART_LSR_OE | UART_LSR_BI | \
59 UART_LSR_PE | UART_LSR_FE)
60#define TEGRA_UART_IRDA_CSR 0x08
61#define TEGRA_UART_SIR_ENABLED 0x80
62
63#define TEGRA_UART_TX_PIO 1
64#define TEGRA_UART_TX_DMA 2
65#define TEGRA_UART_MIN_DMA 16
66#define TEGRA_UART_FIFO_SIZE 32
67
68
69
70
71
72#define TEGRA_UART_TX_TRIG_16B 0x00
73#define TEGRA_UART_TX_TRIG_8B 0x10
74#define TEGRA_UART_TX_TRIG_4B 0x20
75#define TEGRA_UART_TX_TRIG_1B 0x30
76
77#define TEGRA_UART_MAXIMUM 5
78
79
80#define TEGRA_UART_DEFAULT_BAUD 115200
81#define TEGRA_UART_DEFAULT_LSR UART_LCR_WLEN8
82
83
84#define TEGRA_TX_PIO 1
85#define TEGRA_TX_DMA 2
86
87
88
89
90
91
92
93
94
95struct tegra_uart_chip_data {
96 bool tx_fifo_full_status;
97 bool allow_txfifo_reset_fifo_mode;
98 bool support_clk_src_div;
99};
100
101struct tegra_uart_port {
102 struct uart_port uport;
103 const struct tegra_uart_chip_data *cdata;
104
105 struct clk *uart_clk;
106 unsigned int current_baud;
107
108
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 int dma_req_sel;
124
125 struct dma_chan *rx_dma_chan;
126 struct dma_chan *tx_dma_chan;
127 dma_addr_t rx_dma_buf_phys;
128 dma_addr_t tx_dma_buf_phys;
129 unsigned char *rx_dma_buf_virt;
130 unsigned char *tx_dma_buf_virt;
131 struct dma_async_tx_descriptor *tx_dma_desc;
132 struct dma_async_tx_descriptor *rx_dma_desc;
133 dma_cookie_t tx_cookie;
134 dma_cookie_t rx_cookie;
135 int tx_bytes_requested;
136 int rx_bytes_requested;
137};
138
139static void tegra_uart_start_next_tx(struct tegra_uart_port *tup);
140static int tegra_uart_start_rx_dma(struct tegra_uart_port *tup);
141
142static inline unsigned long tegra_uart_read(struct tegra_uart_port *tup,
143 unsigned long reg)
144{
145 return readl(tup->uport.membase + (reg << tup->uport.regshift));
146}
147
148static inline void tegra_uart_write(struct tegra_uart_port *tup, unsigned val,
149 unsigned long reg)
150{
151 writel(val, tup->uport.membase + (reg << tup->uport.regshift));
152}
153
154static inline struct tegra_uart_port *to_tegra_uport(struct uart_port *u)
155{
156 return container_of(u, struct tegra_uart_port, uport);
157}
158
159static unsigned int tegra_uart_get_mctrl(struct uart_port *u)
160{
161 struct tegra_uart_port *tup = to_tegra_uport(u);
162
163
164
165
166
167
168
169
170
171
172 if (tup->enable_modem_interrupt)
173 return TIOCM_RI | TIOCM_CD | TIOCM_DSR | TIOCM_CTS;
174 return TIOCM_CTS;
175}
176
177static void set_rts(struct tegra_uart_port *tup, bool active)
178{
179 unsigned long mcr;
180
181 mcr = tup->mcr_shadow;
182 if (active)
183 mcr |= TEGRA_UART_MCR_RTS_EN;
184 else
185 mcr &= ~TEGRA_UART_MCR_RTS_EN;
186 if (mcr != tup->mcr_shadow) {
187 tegra_uart_write(tup, mcr, UART_MCR);
188 tup->mcr_shadow = mcr;
189 }
190 return;
191}
192
193static void set_dtr(struct tegra_uart_port *tup, bool active)
194{
195 unsigned long mcr;
196
197 mcr = tup->mcr_shadow;
198 if (active)
199 mcr |= UART_MCR_DTR;
200 else
201 mcr &= ~UART_MCR_DTR;
202 if (mcr != tup->mcr_shadow) {
203 tegra_uart_write(tup, mcr, UART_MCR);
204 tup->mcr_shadow = mcr;
205 }
206 return;
207}
208
209static void tegra_uart_set_mctrl(struct uart_port *u, unsigned int mctrl)
210{
211 struct tegra_uart_port *tup = to_tegra_uport(u);
212 unsigned long mcr;
213 int dtr_enable;
214
215 mcr = tup->mcr_shadow;
216 tup->rts_active = !!(mctrl & TIOCM_RTS);
217 set_rts(tup, tup->rts_active);
218
219 dtr_enable = !!(mctrl & TIOCM_DTR);
220 set_dtr(tup, dtr_enable);
221 return;
222}
223
224static void tegra_uart_break_ctl(struct uart_port *u, int break_ctl)
225{
226 struct tegra_uart_port *tup = to_tegra_uport(u);
227 unsigned long lcr;
228
229 lcr = tup->lcr_shadow;
230 if (break_ctl)
231 lcr |= UART_LCR_SBC;
232 else
233 lcr &= ~UART_LCR_SBC;
234 tegra_uart_write(tup, lcr, UART_LCR);
235 tup->lcr_shadow = lcr;
236}
237
238
239static void tegra_uart_wait_sym_time(struct tegra_uart_port *tup,
240 unsigned int syms)
241{
242 if (tup->current_baud)
243 udelay(DIV_ROUND_UP(syms * tup->symb_bit * 1000000,
244 tup->current_baud));
245}
246
247static void tegra_uart_fifo_reset(struct tegra_uart_port *tup, u8 fcr_bits)
248{
249 unsigned long fcr = tup->fcr_shadow;
250
251 if (tup->cdata->allow_txfifo_reset_fifo_mode) {
252 fcr |= fcr_bits & (UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
253 tegra_uart_write(tup, fcr, UART_FCR);
254 } else {
255 fcr &= ~UART_FCR_ENABLE_FIFO;
256 tegra_uart_write(tup, fcr, UART_FCR);
257 udelay(60);
258 fcr |= fcr_bits & (UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
259 tegra_uart_write(tup, fcr, UART_FCR);
260 fcr |= UART_FCR_ENABLE_FIFO;
261 tegra_uart_write(tup, fcr, UART_FCR);
262 }
263
264
265 tegra_uart_read(tup, UART_SCR);
266
267
268 tegra_uart_wait_sym_time(tup, 1);
269}
270
271static int tegra_set_baudrate(struct tegra_uart_port *tup, unsigned int baud)
272{
273 unsigned long rate;
274 unsigned int divisor;
275 unsigned long lcr;
276 int ret;
277
278 if (tup->current_baud == baud)
279 return 0;
280
281 if (tup->cdata->support_clk_src_div) {
282 rate = baud * 16;
283 ret = clk_set_rate(tup->uart_clk, rate);
284 if (ret < 0) {
285 dev_err(tup->uport.dev,
286 "clk_set_rate() failed for rate %lu\n", rate);
287 return ret;
288 }
289 divisor = 1;
290 } else {
291 rate = clk_get_rate(tup->uart_clk);
292 divisor = DIV_ROUND_CLOSEST(rate, baud * 16);
293 }
294
295 lcr = tup->lcr_shadow;
296 lcr |= UART_LCR_DLAB;
297 tegra_uart_write(tup, lcr, UART_LCR);
298
299 tegra_uart_write(tup, divisor & 0xFF, UART_TX);
300 tegra_uart_write(tup, ((divisor >> 8) & 0xFF), UART_IER);
301
302 lcr &= ~UART_LCR_DLAB;
303 tegra_uart_write(tup, lcr, UART_LCR);
304
305
306 tegra_uart_read(tup, UART_SCR);
307
308 tup->current_baud = baud;
309
310
311 tegra_uart_wait_sym_time(tup, 2);
312 return 0;
313}
314
315static char tegra_uart_decode_rx_error(struct tegra_uart_port *tup,
316 unsigned long lsr)
317{
318 char flag = TTY_NORMAL;
319
320 if (unlikely(lsr & TEGRA_UART_LSR_ANY)) {
321 if (lsr & UART_LSR_OE) {
322
323 flag |= TTY_OVERRUN;
324 tup->uport.icount.overrun++;
325 dev_err(tup->uport.dev, "Got overrun errors\n");
326 } else if (lsr & UART_LSR_PE) {
327
328 flag |= TTY_PARITY;
329 tup->uport.icount.parity++;
330 dev_err(tup->uport.dev, "Got Parity errors\n");
331 } else if (lsr & UART_LSR_FE) {
332 flag |= TTY_FRAME;
333 tup->uport.icount.frame++;
334 dev_err(tup->uport.dev, "Got frame errors\n");
335 } else if (lsr & UART_LSR_BI) {
336 dev_err(tup->uport.dev, "Got Break\n");
337 tup->uport.icount.brk++;
338
339 if (!(lsr & UART_LSR_DR) && (lsr & UART_LSR_FIFOE))
340 tegra_uart_fifo_reset(tup, UART_FCR_CLEAR_RCVR);
341 }
342 }
343 return flag;
344}
345
346static int tegra_uart_request_port(struct uart_port *u)
347{
348 return 0;
349}
350
351static void tegra_uart_release_port(struct uart_port *u)
352{
353
354}
355
356static void tegra_uart_fill_tx_fifo(struct tegra_uart_port *tup, int max_bytes)
357{
358 struct circ_buf *xmit = &tup->uport.state->xmit;
359 int i;
360
361 for (i = 0; i < max_bytes; i++) {
362 BUG_ON(uart_circ_empty(xmit));
363 if (tup->cdata->tx_fifo_full_status) {
364 unsigned long lsr = tegra_uart_read(tup, UART_LSR);
365 if ((lsr & TEGRA_UART_LSR_TXFIFO_FULL))
366 break;
367 }
368 tegra_uart_write(tup, xmit->buf[xmit->tail], UART_TX);
369 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
370 tup->uport.icount.tx++;
371 }
372}
373
374static void tegra_uart_start_pio_tx(struct tegra_uart_port *tup,
375 unsigned int bytes)
376{
377 if (bytes > TEGRA_UART_MIN_DMA)
378 bytes = TEGRA_UART_MIN_DMA;
379
380 tup->tx_in_progress = TEGRA_UART_TX_PIO;
381 tup->tx_bytes = bytes;
382 tup->ier_shadow |= UART_IER_THRI;
383 tegra_uart_write(tup, tup->ier_shadow, UART_IER);
384}
385
386static void tegra_uart_tx_dma_complete(void *args)
387{
388 struct tegra_uart_port *tup = args;
389 struct circ_buf *xmit = &tup->uport.state->xmit;
390 struct dma_tx_state state;
391 unsigned long flags;
392 int count;
393
394 dmaengine_tx_status(tup->tx_dma_chan, tup->rx_cookie, &state);
395 count = tup->tx_bytes_requested - state.residue;
396 async_tx_ack(tup->tx_dma_desc);
397 spin_lock_irqsave(&tup->uport.lock, flags);
398 xmit->tail = (xmit->tail + count) & (UART_XMIT_SIZE - 1);
399 tup->tx_in_progress = 0;
400 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
401 uart_write_wakeup(&tup->uport);
402 tegra_uart_start_next_tx(tup);
403 spin_unlock_irqrestore(&tup->uport.lock, flags);
404}
405
406static int tegra_uart_start_tx_dma(struct tegra_uart_port *tup,
407 unsigned long count)
408{
409 struct circ_buf *xmit = &tup->uport.state->xmit;
410 dma_addr_t tx_phys_addr;
411
412 dma_sync_single_for_device(tup->uport.dev, tup->tx_dma_buf_phys,
413 UART_XMIT_SIZE, DMA_TO_DEVICE);
414
415 tup->tx_bytes = count & ~(0xF);
416 tx_phys_addr = tup->tx_dma_buf_phys + xmit->tail;
417 tup->tx_dma_desc = dmaengine_prep_slave_single(tup->tx_dma_chan,
418 tx_phys_addr, tup->tx_bytes, DMA_MEM_TO_DEV,
419 DMA_PREP_INTERRUPT);
420 if (!tup->tx_dma_desc) {
421 dev_err(tup->uport.dev, "Not able to get desc for Tx\n");
422 return -EIO;
423 }
424
425 tup->tx_dma_desc->callback = tegra_uart_tx_dma_complete;
426 tup->tx_dma_desc->callback_param = tup;
427 tup->tx_in_progress = TEGRA_UART_TX_DMA;
428 tup->tx_bytes_requested = tup->tx_bytes;
429 tup->tx_cookie = dmaengine_submit(tup->tx_dma_desc);
430 dma_async_issue_pending(tup->tx_dma_chan);
431 return 0;
432}
433
434static void tegra_uart_start_next_tx(struct tegra_uart_port *tup)
435{
436 unsigned long tail;
437 unsigned long count;
438 struct circ_buf *xmit = &tup->uport.state->xmit;
439
440 tail = (unsigned long)&xmit->buf[xmit->tail];
441 count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
442 if (!count)
443 return;
444
445 if (count < TEGRA_UART_MIN_DMA)
446 tegra_uart_start_pio_tx(tup, count);
447 else if (BYTES_TO_ALIGN(tail) > 0)
448 tegra_uart_start_pio_tx(tup, BYTES_TO_ALIGN(tail));
449 else
450 tegra_uart_start_tx_dma(tup, count);
451}
452
453
454static void tegra_uart_start_tx(struct uart_port *u)
455{
456 struct tegra_uart_port *tup = to_tegra_uport(u);
457 struct circ_buf *xmit = &u->state->xmit;
458
459 if (!uart_circ_empty(xmit) && !tup->tx_in_progress)
460 tegra_uart_start_next_tx(tup);
461}
462
463static unsigned int tegra_uart_tx_empty(struct uart_port *u)
464{
465 struct tegra_uart_port *tup = to_tegra_uport(u);
466 unsigned int ret = 0;
467 unsigned long flags;
468
469 spin_lock_irqsave(&u->lock, flags);
470 if (!tup->tx_in_progress) {
471 unsigned long lsr = tegra_uart_read(tup, UART_LSR);
472 if ((lsr & TX_EMPTY_STATUS) == TX_EMPTY_STATUS)
473 ret = TIOCSER_TEMT;
474 }
475 spin_unlock_irqrestore(&u->lock, flags);
476 return ret;
477}
478
479static void tegra_uart_stop_tx(struct uart_port *u)
480{
481 struct tegra_uart_port *tup = to_tegra_uport(u);
482 struct circ_buf *xmit = &tup->uport.state->xmit;
483 struct dma_tx_state state;
484 int count;
485
486 dmaengine_terminate_all(tup->tx_dma_chan);
487 dmaengine_tx_status(tup->tx_dma_chan, tup->tx_cookie, &state);
488 count = tup->tx_bytes_requested - state.residue;
489 async_tx_ack(tup->tx_dma_desc);
490 xmit->tail = (xmit->tail + count) & (UART_XMIT_SIZE - 1);
491 tup->tx_in_progress = 0;
492 return;
493}
494
495static void tegra_uart_handle_tx_pio(struct tegra_uart_port *tup)
496{
497 struct circ_buf *xmit = &tup->uport.state->xmit;
498
499 tegra_uart_fill_tx_fifo(tup, tup->tx_bytes);
500 tup->tx_in_progress = 0;
501 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
502 uart_write_wakeup(&tup->uport);
503 tegra_uart_start_next_tx(tup);
504 return;
505}
506
507static void tegra_uart_handle_rx_pio(struct tegra_uart_port *tup,
508 struct tty_port *tty)
509{
510 do {
511 char flag = TTY_NORMAL;
512 unsigned long lsr = 0;
513 unsigned char ch;
514
515 lsr = tegra_uart_read(tup, UART_LSR);
516 if (!(lsr & UART_LSR_DR))
517 break;
518
519 flag = tegra_uart_decode_rx_error(tup, lsr);
520 ch = (unsigned char) tegra_uart_read(tup, UART_RX);
521 tup->uport.icount.rx++;
522
523 if (!uart_handle_sysrq_char(&tup->uport, ch) && tty)
524 tty_insert_flip_char(tty, ch, flag);
525 } while (1);
526
527 return;
528}
529
530static void tegra_uart_copy_rx_to_tty(struct tegra_uart_port *tup,
531 struct tty_port *tty, int count)
532{
533 int copied;
534
535 tup->uport.icount.rx += count;
536 if (!tty) {
537 dev_err(tup->uport.dev, "No tty port\n");
538 return;
539 }
540 dma_sync_single_for_cpu(tup->uport.dev, tup->rx_dma_buf_phys,
541 TEGRA_UART_RX_DMA_BUFFER_SIZE, DMA_FROM_DEVICE);
542 copied = tty_insert_flip_string(tty,
543 ((unsigned char *)(tup->rx_dma_buf_virt)), count);
544 if (copied != count) {
545 WARN_ON(1);
546 dev_err(tup->uport.dev, "RxData copy to tty layer failed\n");
547 }
548 dma_sync_single_for_device(tup->uport.dev, tup->rx_dma_buf_phys,
549 TEGRA_UART_RX_DMA_BUFFER_SIZE, DMA_TO_DEVICE);
550}
551
552static void tegra_uart_rx_dma_complete(void *args)
553{
554 struct tegra_uart_port *tup = args;
555 struct uart_port *u = &tup->uport;
556 int count = tup->rx_bytes_requested;
557 struct tty_struct *tty = tty_port_tty_get(&tup->uport.state->port);
558 struct tty_port *port = &u->state->port;
559 unsigned long flags;
560
561 async_tx_ack(tup->rx_dma_desc);
562 spin_lock_irqsave(&u->lock, flags);
563
564
565 if (tup->rts_active)
566 set_rts(tup, false);
567
568
569 if (count)
570 tegra_uart_copy_rx_to_tty(tup, port, count);
571
572 tegra_uart_handle_rx_pio(tup, port);
573 if (tty) {
574 spin_unlock_irqrestore(&u->lock, flags);
575 tty_flip_buffer_push(port);
576 spin_lock_irqsave(&u->lock, flags);
577 tty_kref_put(tty);
578 }
579 tegra_uart_start_rx_dma(tup);
580
581
582 if (tup->rts_active)
583 set_rts(tup, true);
584
585 spin_unlock_irqrestore(&u->lock, flags);
586}
587
588static void tegra_uart_handle_rx_dma(struct tegra_uart_port *tup,
589 unsigned long *flags)
590{
591 struct dma_tx_state state;
592 struct tty_struct *tty = tty_port_tty_get(&tup->uport.state->port);
593 struct tty_port *port = &tup->uport.state->port;
594 struct uart_port *u = &tup->uport;
595 int count;
596
597
598 if (tup->rts_active)
599 set_rts(tup, false);
600
601 dmaengine_terminate_all(tup->rx_dma_chan);
602 dmaengine_tx_status(tup->rx_dma_chan, tup->rx_cookie, &state);
603 count = tup->rx_bytes_requested - state.residue;
604
605
606 if (count)
607 tegra_uart_copy_rx_to_tty(tup, port, count);
608
609 tegra_uart_handle_rx_pio(tup, port);
610 if (tty) {
611 spin_unlock_irqrestore(&u->lock, *flags);
612 tty_flip_buffer_push(port);
613 spin_lock_irqsave(&u->lock, *flags);
614 tty_kref_put(tty);
615 }
616 tegra_uart_start_rx_dma(tup);
617
618 if (tup->rts_active)
619 set_rts(tup, true);
620}
621
622static int tegra_uart_start_rx_dma(struct tegra_uart_port *tup)
623{
624 unsigned int count = TEGRA_UART_RX_DMA_BUFFER_SIZE;
625
626 tup->rx_dma_desc = dmaengine_prep_slave_single(tup->rx_dma_chan,
627 tup->rx_dma_buf_phys, count, DMA_DEV_TO_MEM,
628 DMA_PREP_INTERRUPT);
629 if (!tup->rx_dma_desc) {
630 dev_err(tup->uport.dev, "Not able to get desc for Rx\n");
631 return -EIO;
632 }
633
634 tup->rx_dma_desc->callback = tegra_uart_rx_dma_complete;
635 tup->rx_dma_desc->callback_param = tup;
636 dma_sync_single_for_device(tup->uport.dev, tup->rx_dma_buf_phys,
637 count, DMA_TO_DEVICE);
638 tup->rx_bytes_requested = count;
639 tup->rx_cookie = dmaengine_submit(tup->rx_dma_desc);
640 dma_async_issue_pending(tup->rx_dma_chan);
641 return 0;
642}
643
644static void tegra_uart_handle_modem_signal_change(struct uart_port *u)
645{
646 struct tegra_uart_port *tup = to_tegra_uport(u);
647 unsigned long msr;
648
649 msr = tegra_uart_read(tup, UART_MSR);
650 if (!(msr & UART_MSR_ANY_DELTA))
651 return;
652
653 if (msr & UART_MSR_TERI)
654 tup->uport.icount.rng++;
655 if (msr & UART_MSR_DDSR)
656 tup->uport.icount.dsr++;
657
658 if (msr & UART_MSR_DDCD)
659 uart_handle_dcd_change(&tup->uport, msr & UART_MSR_DCD);
660
661 if (msr & UART_MSR_DCTS)
662 uart_handle_cts_change(&tup->uport, msr & UART_MSR_CTS);
663 return;
664}
665
666static irqreturn_t tegra_uart_isr(int irq, void *data)
667{
668 struct tegra_uart_port *tup = data;
669 struct uart_port *u = &tup->uport;
670 unsigned long iir;
671 unsigned long ier;
672 bool is_rx_int = false;
673 unsigned long flags;
674
675 spin_lock_irqsave(&u->lock, flags);
676 while (1) {
677 iir = tegra_uart_read(tup, UART_IIR);
678 if (iir & UART_IIR_NO_INT) {
679 if (is_rx_int) {
680 tegra_uart_handle_rx_dma(tup, &flags);
681 if (tup->rx_in_progress) {
682 ier = tup->ier_shadow;
683 ier |= (UART_IER_RLSI | UART_IER_RTOIE |
684 TEGRA_UART_IER_EORD);
685 tup->ier_shadow = ier;
686 tegra_uart_write(tup, ier, UART_IER);
687 }
688 }
689 spin_unlock_irqrestore(&u->lock, flags);
690 return IRQ_HANDLED;
691 }
692
693 switch ((iir >> 1) & 0x7) {
694 case 0:
695 tegra_uart_handle_modem_signal_change(u);
696 break;
697
698 case 1:
699 tup->ier_shadow &= ~UART_IER_THRI;
700 tegra_uart_write(tup, tup->ier_shadow, UART_IER);
701 tegra_uart_handle_tx_pio(tup);
702 break;
703
704 case 4:
705 case 6:
706 case 2:
707 if (!is_rx_int) {
708 is_rx_int = true;
709
710 ier = tup->ier_shadow;
711 ier |= UART_IER_RDI;
712 tegra_uart_write(tup, ier, UART_IER);
713 ier &= ~(UART_IER_RDI | UART_IER_RLSI |
714 UART_IER_RTOIE | TEGRA_UART_IER_EORD);
715 tup->ier_shadow = ier;
716 tegra_uart_write(tup, ier, UART_IER);
717 }
718 break;
719
720 case 3:
721 tegra_uart_decode_rx_error(tup,
722 tegra_uart_read(tup, UART_LSR));
723 break;
724
725 case 5:
726 case 7:
727 break;
728 }
729 }
730}
731
732static void tegra_uart_stop_rx(struct uart_port *u)
733{
734 struct tegra_uart_port *tup = to_tegra_uport(u);
735 struct tty_struct *tty;
736 struct tty_port *port = &u->state->port;
737 struct dma_tx_state state;
738 unsigned long ier;
739 int count;
740
741 if (tup->rts_active)
742 set_rts(tup, false);
743
744 if (!tup->rx_in_progress)
745 return;
746
747 tty = tty_port_tty_get(&tup->uport.state->port);
748
749 tegra_uart_wait_sym_time(tup, 1);
750
751 ier = tup->ier_shadow;
752 ier &= ~(UART_IER_RDI | UART_IER_RLSI | UART_IER_RTOIE |
753 TEGRA_UART_IER_EORD);
754 tup->ier_shadow = ier;
755 tegra_uart_write(tup, ier, UART_IER);
756 tup->rx_in_progress = 0;
757 if (tup->rx_dma_chan) {
758 dmaengine_terminate_all(tup->rx_dma_chan);
759 dmaengine_tx_status(tup->rx_dma_chan, tup->rx_cookie, &state);
760 async_tx_ack(tup->rx_dma_desc);
761 count = tup->rx_bytes_requested - state.residue;
762 tegra_uart_copy_rx_to_tty(tup, port, count);
763 tegra_uart_handle_rx_pio(tup, port);
764 } else {
765 tegra_uart_handle_rx_pio(tup, port);
766 }
767 if (tty) {
768 tty_flip_buffer_push(port);
769 tty_kref_put(tty);
770 }
771 return;
772}
773
774static void tegra_uart_hw_deinit(struct tegra_uart_port *tup)
775{
776 unsigned long flags;
777 unsigned long char_time = DIV_ROUND_UP(10000000, tup->current_baud);
778 unsigned long fifo_empty_time = tup->uport.fifosize * char_time;
779 unsigned long wait_time;
780 unsigned long lsr;
781 unsigned long msr;
782 unsigned long mcr;
783
784
785 tegra_uart_write(tup, 0, UART_IER);
786
787 lsr = tegra_uart_read(tup, UART_LSR);
788 if ((lsr & UART_LSR_TEMT) != UART_LSR_TEMT) {
789 msr = tegra_uart_read(tup, UART_MSR);
790 mcr = tegra_uart_read(tup, UART_MCR);
791 if ((mcr & TEGRA_UART_MCR_CTS_EN) && (msr & UART_MSR_CTS))
792 dev_err(tup->uport.dev,
793 "Tx Fifo not empty, CTS disabled, waiting\n");
794
795
796 while ((lsr & UART_LSR_TEMT) != UART_LSR_TEMT) {
797 wait_time = min(fifo_empty_time, 100lu);
798 udelay(wait_time);
799 fifo_empty_time -= wait_time;
800 if (!fifo_empty_time) {
801 msr = tegra_uart_read(tup, UART_MSR);
802 mcr = tegra_uart_read(tup, UART_MCR);
803 if ((mcr & TEGRA_UART_MCR_CTS_EN) &&
804 (msr & UART_MSR_CTS))
805 dev_err(tup->uport.dev,
806 "Slave not ready\n");
807 break;
808 }
809 lsr = tegra_uart_read(tup, UART_LSR);
810 }
811 }
812
813 spin_lock_irqsave(&tup->uport.lock, flags);
814
815 tegra_uart_fifo_reset(tup, UART_FCR_CLEAR_XMIT | UART_FCR_CLEAR_RCVR);
816 tup->current_baud = 0;
817 spin_unlock_irqrestore(&tup->uport.lock, flags);
818
819 clk_disable_unprepare(tup->uart_clk);
820}
821
822static int tegra_uart_hw_init(struct tegra_uart_port *tup)
823{
824 int ret;
825
826 tup->fcr_shadow = 0;
827 tup->mcr_shadow = 0;
828 tup->lcr_shadow = 0;
829 tup->ier_shadow = 0;
830 tup->current_baud = 0;
831
832 clk_prepare_enable(tup->uart_clk);
833
834
835 tegra_periph_reset_assert(tup->uart_clk);
836 udelay(10);
837 tegra_periph_reset_deassert(tup->uart_clk);
838
839 tup->rx_in_progress = 0;
840 tup->tx_in_progress = 0;
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860 tup->fcr_shadow = UART_FCR_ENABLE_FIFO;
861 tup->fcr_shadow |= UART_FCR_R_TRIG_01;
862 tup->fcr_shadow |= TEGRA_UART_TX_TRIG_16B;
863 tegra_uart_write(tup, tup->fcr_shadow, UART_FCR);
864
865
866
867
868
869
870 tup->lcr_shadow = TEGRA_UART_DEFAULT_LSR;
871 tegra_set_baudrate(tup, TEGRA_UART_DEFAULT_BAUD);
872 tup->fcr_shadow |= UART_FCR_DMA_SELECT;
873 tegra_uart_write(tup, tup->fcr_shadow, UART_FCR);
874
875 ret = tegra_uart_start_rx_dma(tup);
876 if (ret < 0) {
877 dev_err(tup->uport.dev, "Not able to start Rx DMA\n");
878 return ret;
879 }
880 tup->rx_in_progress = 1;
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900 tup->ier_shadow = UART_IER_RLSI | UART_IER_RTOIE | TEGRA_UART_IER_EORD;
901 tegra_uart_write(tup, tup->ier_shadow, UART_IER);
902 return 0;
903}
904
905static int tegra_uart_dma_channel_allocate(struct tegra_uart_port *tup,
906 bool dma_to_memory)
907{
908 struct dma_chan *dma_chan;
909 unsigned char *dma_buf;
910 dma_addr_t dma_phys;
911 int ret;
912 struct dma_slave_config dma_sconfig;
913 dma_cap_mask_t mask;
914
915 dma_cap_zero(mask);
916 dma_cap_set(DMA_SLAVE, mask);
917 dma_chan = dma_request_channel(mask, NULL, NULL);
918 if (!dma_chan) {
919 dev_err(tup->uport.dev,
920 "Dma channel is not available, will try later\n");
921 return -EPROBE_DEFER;
922 }
923
924 if (dma_to_memory) {
925 dma_buf = dma_alloc_coherent(tup->uport.dev,
926 TEGRA_UART_RX_DMA_BUFFER_SIZE,
927 &dma_phys, GFP_KERNEL);
928 if (!dma_buf) {
929 dev_err(tup->uport.dev,
930 "Not able to allocate the dma buffer\n");
931 dma_release_channel(dma_chan);
932 return -ENOMEM;
933 }
934 } else {
935 dma_phys = dma_map_single(tup->uport.dev,
936 tup->uport.state->xmit.buf, UART_XMIT_SIZE,
937 DMA_TO_DEVICE);
938 dma_buf = tup->uport.state->xmit.buf;
939 }
940
941 dma_sconfig.slave_id = tup->dma_req_sel;
942 if (dma_to_memory) {
943 dma_sconfig.src_addr = tup->uport.mapbase;
944 dma_sconfig.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
945 dma_sconfig.src_maxburst = 4;
946 } else {
947 dma_sconfig.dst_addr = tup->uport.mapbase;
948 dma_sconfig.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
949 dma_sconfig.dst_maxburst = 16;
950 }
951
952 ret = dmaengine_slave_config(dma_chan, &dma_sconfig);
953 if (ret < 0) {
954 dev_err(tup->uport.dev,
955 "Dma slave config failed, err = %d\n", ret);
956 goto scrub;
957 }
958
959 if (dma_to_memory) {
960 tup->rx_dma_chan = dma_chan;
961 tup->rx_dma_buf_virt = dma_buf;
962 tup->rx_dma_buf_phys = dma_phys;
963 } else {
964 tup->tx_dma_chan = dma_chan;
965 tup->tx_dma_buf_virt = dma_buf;
966 tup->tx_dma_buf_phys = dma_phys;
967 }
968 return 0;
969
970scrub:
971 dma_release_channel(dma_chan);
972 return ret;
973}
974
975static void tegra_uart_dma_channel_free(struct tegra_uart_port *tup,
976 bool dma_to_memory)
977{
978 struct dma_chan *dma_chan;
979
980 if (dma_to_memory) {
981 dma_free_coherent(tup->uport.dev, TEGRA_UART_RX_DMA_BUFFER_SIZE,
982 tup->rx_dma_buf_virt, tup->rx_dma_buf_phys);
983 dma_chan = tup->rx_dma_chan;
984 tup->rx_dma_chan = NULL;
985 tup->rx_dma_buf_phys = 0;
986 tup->rx_dma_buf_virt = NULL;
987 } else {
988 dma_unmap_single(tup->uport.dev, tup->tx_dma_buf_phys,
989 UART_XMIT_SIZE, DMA_TO_DEVICE);
990 dma_chan = tup->tx_dma_chan;
991 tup->tx_dma_chan = NULL;
992 tup->tx_dma_buf_phys = 0;
993 tup->tx_dma_buf_virt = NULL;
994 }
995 dma_release_channel(dma_chan);
996}
997
998static int tegra_uart_startup(struct uart_port *u)
999{
1000 struct tegra_uart_port *tup = to_tegra_uport(u);
1001 int ret;
1002
1003 ret = tegra_uart_dma_channel_allocate(tup, false);
1004 if (ret < 0) {
1005 dev_err(u->dev, "Tx Dma allocation failed, err = %d\n", ret);
1006 return ret;
1007 }
1008
1009 ret = tegra_uart_dma_channel_allocate(tup, true);
1010 if (ret < 0) {
1011 dev_err(u->dev, "Rx Dma allocation failed, err = %d\n", ret);
1012 goto fail_rx_dma;
1013 }
1014
1015 ret = tegra_uart_hw_init(tup);
1016 if (ret < 0) {
1017 dev_err(u->dev, "Uart HW init failed, err = %d\n", ret);
1018 goto fail_hw_init;
1019 }
1020
1021 ret = request_irq(u->irq, tegra_uart_isr, IRQF_DISABLED,
1022 dev_name(u->dev), tup);
1023 if (ret < 0) {
1024 dev_err(u->dev, "Failed to register ISR for IRQ %d\n", u->irq);
1025 goto fail_hw_init;
1026 }
1027 return 0;
1028
1029fail_hw_init:
1030 tegra_uart_dma_channel_free(tup, true);
1031fail_rx_dma:
1032 tegra_uart_dma_channel_free(tup, false);
1033 return ret;
1034}
1035
1036static void tegra_uart_shutdown(struct uart_port *u)
1037{
1038 struct tegra_uart_port *tup = to_tegra_uport(u);
1039
1040 tegra_uart_hw_deinit(tup);
1041
1042 tup->rx_in_progress = 0;
1043 tup->tx_in_progress = 0;
1044
1045 tegra_uart_dma_channel_free(tup, true);
1046 tegra_uart_dma_channel_free(tup, false);
1047 free_irq(u->irq, tup);
1048}
1049
1050static void tegra_uart_enable_ms(struct uart_port *u)
1051{
1052 struct tegra_uart_port *tup = to_tegra_uport(u);
1053
1054 if (tup->enable_modem_interrupt) {
1055 tup->ier_shadow |= UART_IER_MSI;
1056 tegra_uart_write(tup, tup->ier_shadow, UART_IER);
1057 }
1058}
1059
1060static void tegra_uart_set_termios(struct uart_port *u,
1061 struct ktermios *termios, struct ktermios *oldtermios)
1062{
1063 struct tegra_uart_port *tup = to_tegra_uport(u);
1064 unsigned int baud;
1065 unsigned long flags;
1066 unsigned int lcr;
1067 int symb_bit = 1;
1068 struct clk *parent_clk = clk_get_parent(tup->uart_clk);
1069 unsigned long parent_clk_rate = clk_get_rate(parent_clk);
1070 int max_divider = (tup->cdata->support_clk_src_div) ? 0x7FFF : 0xFFFF;
1071
1072 max_divider *= 16;
1073 spin_lock_irqsave(&u->lock, flags);
1074
1075
1076 if (tup->rts_active)
1077 set_rts(tup, false);
1078
1079
1080 tegra_uart_write(tup, tup->ier_shadow | UART_IER_RDI, UART_IER);
1081 tegra_uart_read(tup, UART_IER);
1082 tegra_uart_write(tup, 0, UART_IER);
1083 tegra_uart_read(tup, UART_IER);
1084
1085
1086 lcr = tup->lcr_shadow;
1087 lcr &= ~UART_LCR_PARITY;
1088
1089
1090 termios->c_cflag &= ~CMSPAR;
1091
1092 if ((termios->c_cflag & PARENB) == PARENB) {
1093 symb_bit++;
1094 if (termios->c_cflag & PARODD) {
1095 lcr |= UART_LCR_PARITY;
1096 lcr &= ~UART_LCR_EPAR;
1097 lcr &= ~UART_LCR_SPAR;
1098 } else {
1099 lcr |= UART_LCR_PARITY;
1100 lcr |= UART_LCR_EPAR;
1101 lcr &= ~UART_LCR_SPAR;
1102 }
1103 }
1104
1105 lcr &= ~UART_LCR_WLEN8;
1106 switch (termios->c_cflag & CSIZE) {
1107 case CS5:
1108 lcr |= UART_LCR_WLEN5;
1109 symb_bit += 5;
1110 break;
1111 case CS6:
1112 lcr |= UART_LCR_WLEN6;
1113 symb_bit += 6;
1114 break;
1115 case CS7:
1116 lcr |= UART_LCR_WLEN7;
1117 symb_bit += 7;
1118 break;
1119 default:
1120 lcr |= UART_LCR_WLEN8;
1121 symb_bit += 8;
1122 break;
1123 }
1124
1125
1126 if (termios->c_cflag & CSTOPB) {
1127 lcr |= UART_LCR_STOP;
1128 symb_bit += 2;
1129 } else {
1130 lcr &= ~UART_LCR_STOP;
1131 symb_bit++;
1132 }
1133
1134 tegra_uart_write(tup, lcr, UART_LCR);
1135 tup->lcr_shadow = lcr;
1136 tup->symb_bit = symb_bit;
1137
1138
1139 baud = uart_get_baud_rate(u, termios, oldtermios,
1140 parent_clk_rate/max_divider,
1141 parent_clk_rate/16);
1142 spin_unlock_irqrestore(&u->lock, flags);
1143 tegra_set_baudrate(tup, baud);
1144 if (tty_termios_baud_rate(termios))
1145 tty_termios_encode_baud_rate(termios, baud, baud);
1146 spin_lock_irqsave(&u->lock, flags);
1147
1148
1149 if (termios->c_cflag & CRTSCTS) {
1150 tup->mcr_shadow |= TEGRA_UART_MCR_CTS_EN;
1151 tup->mcr_shadow &= ~TEGRA_UART_MCR_RTS_EN;
1152 tegra_uart_write(tup, tup->mcr_shadow, UART_MCR);
1153
1154 if (tup->rts_active)
1155 set_rts(tup, true);
1156 } else {
1157 tup->mcr_shadow &= ~TEGRA_UART_MCR_CTS_EN;
1158 tup->mcr_shadow &= ~TEGRA_UART_MCR_RTS_EN;
1159 tegra_uart_write(tup, tup->mcr_shadow, UART_MCR);
1160 }
1161
1162
1163 uart_update_timeout(u, termios->c_cflag, baud);
1164
1165
1166 tegra_uart_read(tup, UART_IER);
1167
1168
1169 tegra_uart_write(tup, tup->ier_shadow, UART_IER);
1170 tegra_uart_read(tup, UART_IER);
1171
1172 spin_unlock_irqrestore(&u->lock, flags);
1173 return;
1174}
1175
1176
1177
1178
1179
1180static void tegra_uart_flush_buffer(struct uart_port *u)
1181{
1182 struct tegra_uart_port *tup = to_tegra_uport(u);
1183
1184 tup->tx_bytes = 0;
1185 if (tup->tx_dma_chan)
1186 dmaengine_terminate_all(tup->tx_dma_chan);
1187 return;
1188}
1189
1190static const char *tegra_uart_type(struct uart_port *u)
1191{
1192 return TEGRA_UART_TYPE;
1193}
1194
1195static struct uart_ops tegra_uart_ops = {
1196 .tx_empty = tegra_uart_tx_empty,
1197 .set_mctrl = tegra_uart_set_mctrl,
1198 .get_mctrl = tegra_uart_get_mctrl,
1199 .stop_tx = tegra_uart_stop_tx,
1200 .start_tx = tegra_uart_start_tx,
1201 .stop_rx = tegra_uart_stop_rx,
1202 .flush_buffer = tegra_uart_flush_buffer,
1203 .enable_ms = tegra_uart_enable_ms,
1204 .break_ctl = tegra_uart_break_ctl,
1205 .startup = tegra_uart_startup,
1206 .shutdown = tegra_uart_shutdown,
1207 .set_termios = tegra_uart_set_termios,
1208 .type = tegra_uart_type,
1209 .request_port = tegra_uart_request_port,
1210 .release_port = tegra_uart_release_port,
1211};
1212
1213static struct uart_driver tegra_uart_driver = {
1214 .owner = THIS_MODULE,
1215 .driver_name = "tegra_hsuart",
1216 .dev_name = "ttyTHS",
1217 .cons = NULL,
1218 .nr = TEGRA_UART_MAXIMUM,
1219};
1220
1221static int tegra_uart_parse_dt(struct platform_device *pdev,
1222 struct tegra_uart_port *tup)
1223{
1224 struct device_node *np = pdev->dev.of_node;
1225 u32 of_dma[2];
1226 int port;
1227
1228 if (of_property_read_u32_array(np, "nvidia,dma-request-selector",
1229 of_dma, 2) >= 0) {
1230 tup->dma_req_sel = of_dma[1];
1231 } else {
1232 dev_err(&pdev->dev, "missing dma requestor in device tree\n");
1233 return -EINVAL;
1234 }
1235
1236 port = of_alias_get_id(np, "serial");
1237 if (port < 0) {
1238 dev_err(&pdev->dev, "failed to get alias id, errno %d\n", port);
1239 return port;
1240 }
1241 tup->uport.line = port;
1242
1243 tup->enable_modem_interrupt = of_property_read_bool(np,
1244 "nvidia,enable-modem-interrupt");
1245 return 0;
1246}
1247
1248static struct tegra_uart_chip_data tegra20_uart_chip_data = {
1249 .tx_fifo_full_status = false,
1250 .allow_txfifo_reset_fifo_mode = true,
1251 .support_clk_src_div = false,
1252};
1253
1254static struct tegra_uart_chip_data tegra30_uart_chip_data = {
1255 .tx_fifo_full_status = true,
1256 .allow_txfifo_reset_fifo_mode = false,
1257 .support_clk_src_div = true,
1258};
1259
1260static struct of_device_id tegra_uart_of_match[] = {
1261 {
1262 .compatible = "nvidia,tegra30-hsuart",
1263 .data = &tegra30_uart_chip_data,
1264 }, {
1265 .compatible = "nvidia,tegra20-hsuart",
1266 .data = &tegra20_uart_chip_data,
1267 }, {
1268 },
1269};
1270MODULE_DEVICE_TABLE(of, tegra_uart_of_match);
1271
1272static int tegra_uart_probe(struct platform_device *pdev)
1273{
1274 struct tegra_uart_port *tup;
1275 struct uart_port *u;
1276 struct resource *resource;
1277 int ret;
1278 const struct tegra_uart_chip_data *cdata;
1279 const struct of_device_id *match;
1280
1281 match = of_match_device(tegra_uart_of_match, &pdev->dev);
1282 if (!match) {
1283 dev_err(&pdev->dev, "Error: No device match found\n");
1284 return -ENODEV;
1285 }
1286 cdata = match->data;
1287
1288 tup = devm_kzalloc(&pdev->dev, sizeof(*tup), GFP_KERNEL);
1289 if (!tup) {
1290 dev_err(&pdev->dev, "Failed to allocate memory for tup\n");
1291 return -ENOMEM;
1292 }
1293
1294 ret = tegra_uart_parse_dt(pdev, tup);
1295 if (ret < 0)
1296 return ret;
1297
1298 u = &tup->uport;
1299 u->dev = &pdev->dev;
1300 u->ops = &tegra_uart_ops;
1301 u->type = PORT_TEGRA;
1302 u->fifosize = 32;
1303 tup->cdata = cdata;
1304
1305 platform_set_drvdata(pdev, tup);
1306 resource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1307 if (!resource) {
1308 dev_err(&pdev->dev, "No IO memory resource\n");
1309 return -ENODEV;
1310 }
1311
1312 u->mapbase = resource->start;
1313 u->membase = devm_ioremap_resource(&pdev->dev, resource);
1314 if (IS_ERR(u->membase))
1315 return PTR_ERR(u->membase);
1316
1317 tup->uart_clk = devm_clk_get(&pdev->dev, NULL);
1318 if (IS_ERR(tup->uart_clk)) {
1319 dev_err(&pdev->dev, "Couldn't get the clock\n");
1320 return PTR_ERR(tup->uart_clk);
1321 }
1322
1323 u->iotype = UPIO_MEM32;
1324 u->irq = platform_get_irq(pdev, 0);
1325 u->regshift = 2;
1326 ret = uart_add_one_port(&tegra_uart_driver, u);
1327 if (ret < 0) {
1328 dev_err(&pdev->dev, "Failed to add uart port, err %d\n", ret);
1329 return ret;
1330 }
1331 return ret;
1332}
1333
1334static int tegra_uart_remove(struct platform_device *pdev)
1335{
1336 struct tegra_uart_port *tup = platform_get_drvdata(pdev);
1337 struct uart_port *u = &tup->uport;
1338
1339 uart_remove_one_port(&tegra_uart_driver, u);
1340 return 0;
1341}
1342
1343#ifdef CONFIG_PM_SLEEP
1344static int tegra_uart_suspend(struct device *dev)
1345{
1346 struct tegra_uart_port *tup = dev_get_drvdata(dev);
1347 struct uart_port *u = &tup->uport;
1348
1349 return uart_suspend_port(&tegra_uart_driver, u);
1350}
1351
1352static int tegra_uart_resume(struct device *dev)
1353{
1354 struct tegra_uart_port *tup = dev_get_drvdata(dev);
1355 struct uart_port *u = &tup->uport;
1356
1357 return uart_resume_port(&tegra_uart_driver, u);
1358}
1359#endif
1360
1361static const struct dev_pm_ops tegra_uart_pm_ops = {
1362 SET_SYSTEM_SLEEP_PM_OPS(tegra_uart_suspend, tegra_uart_resume)
1363};
1364
1365static struct platform_driver tegra_uart_platform_driver = {
1366 .probe = tegra_uart_probe,
1367 .remove = tegra_uart_remove,
1368 .driver = {
1369 .name = "serial-tegra",
1370 .of_match_table = tegra_uart_of_match,
1371 .pm = &tegra_uart_pm_ops,
1372 },
1373};
1374
1375static int __init tegra_uart_init(void)
1376{
1377 int ret;
1378
1379 ret = uart_register_driver(&tegra_uart_driver);
1380 if (ret < 0) {
1381 pr_err("Could not register %s driver\n",
1382 tegra_uart_driver.driver_name);
1383 return ret;
1384 }
1385
1386 ret = platform_driver_register(&tegra_uart_platform_driver);
1387 if (ret < 0) {
1388 pr_err("Uart platform driver register failed, e = %d\n", ret);
1389 uart_unregister_driver(&tegra_uart_driver);
1390 return ret;
1391 }
1392 return 0;
1393}
1394
1395static void __exit tegra_uart_exit(void)
1396{
1397 pr_info("Unloading tegra uart driver\n");
1398 platform_driver_unregister(&tegra_uart_platform_driver);
1399 uart_unregister_driver(&tegra_uart_driver);
1400}
1401
1402module_init(tegra_uart_init);
1403module_exit(tegra_uart_exit);
1404
1405MODULE_ALIAS("platform:serial-tegra");
1406MODULE_DESCRIPTION("High speed UART driver for tegra chipset");
1407MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
1408MODULE_LICENSE("GPL v2");
1409
