1 /*
2 * Driver for AMBA serial ports
3 *
4 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
5 *
6 * Copyright 1999 ARM Limited
7 * Copyright (C) 2000 Deep Blue Solutions Ltd.
8 * Copyright (C) 2010 ST-Ericsson SA
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 *
24 * This is a generic driver for ARM AMBA-type serial ports. They
25 * have a lot of 16550-like features, but are not register compatible.
26 * Note that although they do have CTS, DCD and DSR inputs, they do
27 * not have an RI input, nor do they have DTR or RTS outputs. If
28 * required, these have to be supplied via some other means (eg, GPIO)
29 * and hooked into this driver.
30 */
31
32 #if defined(CONFIG_SERIAL_AMBA_PL011_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
33 #define SUPPORT_SYSRQ
34 #endif
35
36 #include <linux/module.h>
37 #include <linux/ioport.h>
38 #include <linux/init.h>
39 #include <linux/console.h>
40 #include <linux/sysrq.h>
41 #include <linux/device.h>
42 #include <linux/tty.h>
43 #include <linux/tty_flip.h>
44 #include <linux/serial_core.h>
45 #include <linux/serial.h>
46 #include <linux/amba/bus.h>
47 #include <linux/amba/serial.h>
48 #include <linux/clk.h>
49 #include <linux/slab.h>
50 #include <linux/dmaengine.h>
51 #include <linux/dma-mapping.h>
52 #include <linux/scatterlist.h>
53 #include <linux/delay.h>
54
55 #include <asm/io.h>
56 #include <asm/sizes.h>
57
58 #define UART_NR 14
59
60 #define SERIAL_AMBA_MAJOR 204
61 #define SERIAL_AMBA_MINOR 64
62 #define SERIAL_AMBA_NR UART_NR
63
64 #define AMBA_ISR_PASS_LIMIT 256
65
66 #define UART_DR_ERROR (UART011_DR_OE|UART011_DR_BE|UART011_DR_PE|UART011_DR_FE)
67 #define UART_DUMMY_DR_RX (1 << 16)
68
69
70 #define UART_WA_SAVE_NR 14
71
72 static void pl011_lockup_wa(unsigned long data);
73 static const u32 uart_wa_reg[UART_WA_SAVE_NR] = {
74 ST_UART011_DMAWM,
75 ST_UART011_TIMEOUT,
76 ST_UART011_LCRH_RX,
77 UART011_IBRD,
78 UART011_FBRD,
79 ST_UART011_LCRH_TX,
80 UART011_IFLS,
81 ST_UART011_XFCR,
82 ST_UART011_XON1,
83 ST_UART011_XON2,
84 ST_UART011_XOFF1,
85 ST_UART011_XOFF2,
86 UART011_CR,
87 UART011_IMSC
88 };
89
90 static u32 uart_wa_regdata[UART_WA_SAVE_NR];
91 static DECLARE_TASKLET(pl011_lockup_tlet, pl011_lockup_wa, 0);
92
93 /* There is by now at least one vendor with differing details, so handle it */
94 struct vendor_data {
95 unsigned int ifls;
96 unsigned int fifosize;
97 unsigned int lcrh_tx;
98 unsigned int lcrh_rx;
99 bool oversampling;
100 bool interrupt_may_hang; /* vendor-specific */
101 bool dma_threshold;
102 };
103
104 static struct vendor_data vendor_arm = {
105 .ifls = UART011_IFLS_RX4_8|UART011_IFLS_TX4_8,
106 .fifosize = 16,
107 .lcrh_tx = UART011_LCRH,
108 .lcrh_rx = UART011_LCRH,
109 .oversampling = false,
110 .dma_threshold = false,
111 };
112
113 static struct vendor_data vendor_st = {
114 .ifls = UART011_IFLS_RX_HALF|UART011_IFLS_TX_HALF,
115 .fifosize = 64,
116 .lcrh_tx = ST_UART011_LCRH_TX,
117 .lcrh_rx = ST_UART011_LCRH_RX,
118 .oversampling = true,
119 .interrupt_may_hang = true,
120 .dma_threshold = true,
121 };
122
123 static struct uart_amba_port *amba_ports[UART_NR];
124
125 /* Deals with DMA transactions */
126
127 struct pl011_sgbuf {
128 struct scatterlist sg;
129 char *buf;
130 };
131
132 struct pl011_dmarx_data {
133 struct dma_chan *chan;
134 struct completion complete;
135 bool use_buf_b;
136 struct pl011_sgbuf sgbuf_a;
137 struct pl011_sgbuf sgbuf_b;
138 dma_cookie_t cookie;
139 bool running;
140 };
141
142 struct pl011_dmatx_data {
143 struct dma_chan *chan;
144 struct scatterlist sg;
145 char *buf;
146 bool queued;
147 };
148
149 /*
150 * We wrap our port structure around the generic uart_port.
151 */
152 struct uart_amba_port {
153 struct uart_port port;
154 struct clk *clk;
155 const struct vendor_data *vendor;
156 unsigned int dmacr; /* dma control reg */
157 unsigned int im; /* interrupt mask */
158 unsigned int old_status;
159 unsigned int fifosize; /* vendor-specific */
160 unsigned int lcrh_tx; /* vendor-specific */
161 unsigned int lcrh_rx; /* vendor-specific */
162 unsigned int old_cr; /* state during shutdown */
163 bool autorts;
164 char type[12];
165 bool interrupt_may_hang; /* vendor-specific */
166 #ifdef CONFIG_DMA_ENGINE
167 /* DMA stuff */
168 bool using_tx_dma;
169 bool using_rx_dma;
170 struct pl011_dmarx_data dmarx;
171 struct pl011_dmatx_data dmatx;
172 #endif
173 };
174
175 /*
176 * Reads up to 256 characters from the FIFO or until it's empty and
177 * inserts them into the TTY layer. Returns the number of characters
178 * read from the FIFO.
179 */
pl011_fifo_to_tty(struct uart_amba_port * uap)180 static int pl011_fifo_to_tty(struct uart_amba_port *uap)
181 {
182 u16 status, ch;
183 unsigned int flag, max_count = 256;
184 int fifotaken = 0;
185
186 while (max_count--) {
187 status = readw(uap->port.membase + UART01x_FR);
188 if (status & UART01x_FR_RXFE)
189 break;
190
191 /* Take chars from the FIFO and update status */
192 ch = readw(uap->port.membase + UART01x_DR) |
193 UART_DUMMY_DR_RX;
194 flag = TTY_NORMAL;
195 uap->port.icount.rx++;
196 fifotaken++;
197
198 if (unlikely(ch & UART_DR_ERROR)) {
199 if (ch & UART011_DR_BE) {
200 ch &= ~(UART011_DR_FE | UART011_DR_PE);
201 uap->port.icount.brk++;
202 if (uart_handle_break(&uap->port))
203 continue;
204 } else if (ch & UART011_DR_PE)
205 uap->port.icount.parity++;
206 else if (ch & UART011_DR_FE)
207 uap->port.icount.frame++;
208 if (ch & UART011_DR_OE)
209 uap->port.icount.overrun++;
210
211 ch &= uap->port.read_status_mask;
212
213 if (ch & UART011_DR_BE)
214 flag = TTY_BREAK;
215 else if (ch & UART011_DR_PE)
216 flag = TTY_PARITY;
217 else if (ch & UART011_DR_FE)
218 flag = TTY_FRAME;
219 }
220
221 if (uart_handle_sysrq_char(&uap->port, ch & 255))
222 continue;
223
224 uart_insert_char(&uap->port, ch, UART011_DR_OE, ch, flag);
225 }
226
227 return fifotaken;
228 }
229
230
231 /*
232 * All the DMA operation mode stuff goes inside this ifdef.
233 * This assumes that you have a generic DMA device interface,
234 * no custom DMA interfaces are supported.
235 */
236 #ifdef CONFIG_DMA_ENGINE
237
238 #define PL011_DMA_BUFFER_SIZE PAGE_SIZE
239
pl011_sgbuf_init(struct dma_chan * chan,struct pl011_sgbuf * sg,enum dma_data_direction dir)240 static int pl011_sgbuf_init(struct dma_chan *chan, struct pl011_sgbuf *sg,
241 enum dma_data_direction dir)
242 {
243 sg->buf = kmalloc(PL011_DMA_BUFFER_SIZE, GFP_KERNEL);
244 if (!sg->buf)
245 return -ENOMEM;
246
247 sg_init_one(&sg->sg, sg->buf, PL011_DMA_BUFFER_SIZE);
248
249 if (dma_map_sg(chan->device->dev, &sg->sg, 1, dir) != 1) {
250 kfree(sg->buf);
251 return -EINVAL;
252 }
253 return 0;
254 }
255
pl011_sgbuf_free(struct dma_chan * chan,struct pl011_sgbuf * sg,enum dma_data_direction dir)256 static void pl011_sgbuf_free(struct dma_chan *chan, struct pl011_sgbuf *sg,
257 enum dma_data_direction dir)
258 {
259 if (sg->buf) {
260 dma_unmap_sg(chan->device->dev, &sg->sg, 1, dir);
261 kfree(sg->buf);
262 }
263 }
264
pl011_dma_probe_initcall(struct uart_amba_port * uap)265 static void pl011_dma_probe_initcall(struct uart_amba_port *uap)
266 {
267 /* DMA is the sole user of the platform data right now */
268 struct amba_pl011_data *plat = uap->port.dev->platform_data;
269 struct dma_slave_config tx_conf = {
270 .dst_addr = uap->port.mapbase + UART01x_DR,
271 .dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE,
272 .direction = DMA_MEM_TO_DEV,
273 .dst_maxburst = uap->fifosize >> 1,
274 };
275 struct dma_chan *chan;
276 dma_cap_mask_t mask;
277
278 /* We need platform data */
279 if (!plat || !plat->dma_filter) {
280 dev_info(uap->port.dev, "no DMA platform data\n");
281 return;
282 }
283
284 /* Try to acquire a generic DMA engine slave TX channel */
285 dma_cap_zero(mask);
286 dma_cap_set(DMA_SLAVE, mask);
287
288 chan = dma_request_channel(mask, plat->dma_filter, plat->dma_tx_param);
289 if (!chan) {
290 dev_err(uap->port.dev, "no TX DMA channel!\n");
291 return;
292 }
293
294 dmaengine_slave_config(chan, &tx_conf);
295 uap->dmatx.chan = chan;
296
297 dev_info(uap->port.dev, "DMA channel TX %s\n",
298 dma_chan_name(uap->dmatx.chan));
299
300 /* Optionally make use of an RX channel as well */
301 if (plat->dma_rx_param) {
302 struct dma_slave_config rx_conf = {
303 .src_addr = uap->port.mapbase + UART01x_DR,
304 .src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE,
305 .direction = DMA_DEV_TO_MEM,
306 .src_maxburst = uap->fifosize >> 1,
307 };
308
309 chan = dma_request_channel(mask, plat->dma_filter, plat->dma_rx_param);
310 if (!chan) {
311 dev_err(uap->port.dev, "no RX DMA channel!\n");
312 return;
313 }
314
315 dmaengine_slave_config(chan, &rx_conf);
316 uap->dmarx.chan = chan;
317
318 dev_info(uap->port.dev, "DMA channel RX %s\n",
319 dma_chan_name(uap->dmarx.chan));
320 }
321 }
322
323 #ifndef MODULE
324 /*
325 * Stack up the UARTs and let the above initcall be done at device
326 * initcall time, because the serial driver is called as an arch
327 * initcall, and at this time the DMA subsystem is not yet registered.
328 * At this point the driver will switch over to using DMA where desired.
329 */
330 struct dma_uap {
331 struct list_head node;
332 struct uart_amba_port *uap;
333 };
334
335 static LIST_HEAD(pl011_dma_uarts);
336
pl011_dma_initcall(void)337 static int __init pl011_dma_initcall(void)
338 {
339 struct list_head *node, *tmp;
340
341 list_for_each_safe(node, tmp, &pl011_dma_uarts) {
342 struct dma_uap *dmau = list_entry(node, struct dma_uap, node);
343 pl011_dma_probe_initcall(dmau->uap);
344 list_del(node);
345 kfree(dmau);
346 }
347 return 0;
348 }
349
350 device_initcall(pl011_dma_initcall);
351
pl011_dma_probe(struct uart_amba_port * uap)352 static void pl011_dma_probe(struct uart_amba_port *uap)
353 {
354 struct dma_uap *dmau = kzalloc(sizeof(struct dma_uap), GFP_KERNEL);
355 if (dmau) {
356 dmau->uap = uap;
357 list_add_tail(&dmau->node, &pl011_dma_uarts);
358 }
359 }
360 #else
pl011_dma_probe(struct uart_amba_port * uap)361 static void pl011_dma_probe(struct uart_amba_port *uap)
362 {
363 pl011_dma_probe_initcall(uap);
364 }
365 #endif
366
pl011_dma_remove(struct uart_amba_port * uap)367 static void pl011_dma_remove(struct uart_amba_port *uap)
368 {
369 /* TODO: remove the initcall if it has not yet executed */
370 if (uap->dmatx.chan)
371 dma_release_channel(uap->dmatx.chan);
372 if (uap->dmarx.chan)
373 dma_release_channel(uap->dmarx.chan);
374 }
375
376 /* Forward declare this for the refill routine */
377 static int pl011_dma_tx_refill(struct uart_amba_port *uap);
378
379 /*
380 * The current DMA TX buffer has been sent.
381 * Try to queue up another DMA buffer.
382 */
pl011_dma_tx_callback(void * data)383 static void pl011_dma_tx_callback(void *data)
384 {
385 struct uart_amba_port *uap = data;
386 struct pl011_dmatx_data *dmatx = &uap->dmatx;
387 unsigned long flags;
388 u16 dmacr;
389
390 spin_lock_irqsave(&uap->port.lock, flags);
391 if (uap->dmatx.queued)
392 dma_unmap_sg(dmatx->chan->device->dev, &dmatx->sg, 1,
393 DMA_TO_DEVICE);
394
395 dmacr = uap->dmacr;
396 uap->dmacr = dmacr & ~UART011_TXDMAE;
397 writew(uap->dmacr, uap->port.membase + UART011_DMACR);
398
399 /*
400 * If TX DMA was disabled, it means that we've stopped the DMA for
401 * some reason (eg, XOFF received, or we want to send an X-char.)
402 *
403 * Note: we need to be careful here of a potential race between DMA
404 * and the rest of the driver - if the driver disables TX DMA while
405 * a TX buffer completing, we must update the tx queued status to
406 * get further refills (hence we check dmacr).
407 */
408 if (!(dmacr & UART011_TXDMAE) || uart_tx_stopped(&uap->port) ||
409 uart_circ_empty(&uap->port.state->xmit)) {
410 uap->dmatx.queued = false;
411 spin_unlock_irqrestore(&uap->port.lock, flags);
412 return;
413 }
414
415 if (pl011_dma_tx_refill(uap) <= 0) {
416 /*
417 * We didn't queue a DMA buffer for some reason, but we
418 * have data pending to be sent. Re-enable the TX IRQ.
419 */
420 uap->im |= UART011_TXIM;
421 writew(uap->im, uap->port.membase + UART011_IMSC);
422 }
423 spin_unlock_irqrestore(&uap->port.lock, flags);
424 }
425
426 /*
427 * Try to refill the TX DMA buffer.
428 * Locking: called with port lock held and IRQs disabled.
429 * Returns:
430 * 1 if we queued up a TX DMA buffer.
431 * 0 if we didn't want to handle this by DMA
432 * <0 on error
433 */
pl011_dma_tx_refill(struct uart_amba_port * uap)434 static int pl011_dma_tx_refill(struct uart_amba_port *uap)
435 {
436 struct pl011_dmatx_data *dmatx = &uap->dmatx;
437 struct dma_chan *chan = dmatx->chan;
438 struct dma_device *dma_dev = chan->device;
439 struct dma_async_tx_descriptor *desc;
440 struct circ_buf *xmit = &uap->port.state->xmit;
441 unsigned int count;
442
443 /*
444 * Try to avoid the overhead involved in using DMA if the
445 * transaction fits in the first half of the FIFO, by using
446 * the standard interrupt handling. This ensures that we
447 * issue a uart_write_wakeup() at the appropriate time.
448 */
449 count = uart_circ_chars_pending(xmit);
450 if (count < (uap->fifosize >> 1)) {
451 uap->dmatx.queued = false;
452 return 0;
453 }
454
455 /*
456 * Bodge: don't send the last character by DMA, as this
457 * will prevent XON from notifying us to restart DMA.
458 */
459 count -= 1;
460
461 /* Else proceed to copy the TX chars to the DMA buffer and fire DMA */
462 if (count > PL011_DMA_BUFFER_SIZE)
463 count = PL011_DMA_BUFFER_SIZE;
464
465 if (xmit->tail < xmit->head)
466 memcpy(&dmatx->buf[0], &xmit->buf[xmit->tail], count);
467 else {
468 size_t first = UART_XMIT_SIZE - xmit->tail;
469 size_t second = xmit->head;
470
471 memcpy(&dmatx->buf[0], &xmit->buf[xmit->tail], first);
472 if (second)
473 memcpy(&dmatx->buf[first], &xmit->buf[0], second);
474 }
475
476 dmatx->sg.length = count;
477
478 if (dma_map_sg(dma_dev->dev, &dmatx->sg, 1, DMA_TO_DEVICE) != 1) {
479 uap->dmatx.queued = false;
480 dev_dbg(uap->port.dev, "unable to map TX DMA\n");
481 return -EBUSY;
482 }
483
484 desc = dma_dev->device_prep_slave_sg(chan, &dmatx->sg, 1, DMA_MEM_TO_DEV,
485 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
486 if (!desc) {
487 dma_unmap_sg(dma_dev->dev, &dmatx->sg, 1, DMA_TO_DEVICE);
488 uap->dmatx.queued = false;
489 /*
490 * If DMA cannot be used right now, we complete this
491 * transaction via IRQ and let the TTY layer retry.
492 */
493 dev_dbg(uap->port.dev, "TX DMA busy\n");
494 return -EBUSY;
495 }
496
497 /* Some data to go along to the callback */
498 desc->callback = pl011_dma_tx_callback;
499 desc->callback_param = uap;
500
501 /* All errors should happen at prepare time */
502 dmaengine_submit(desc);
503
504 /* Fire the DMA transaction */
505 dma_dev->device_issue_pending(chan);
506
507 uap->dmacr |= UART011_TXDMAE;
508 writew(uap->dmacr, uap->port.membase + UART011_DMACR);
509 uap->dmatx.queued = true;
510
511 /*
512 * Now we know that DMA will fire, so advance the ring buffer
513 * with the stuff we just dispatched.
514 */
515 xmit->tail = (xmit->tail + count) & (UART_XMIT_SIZE - 1);
516 uap->port.icount.tx += count;
517
518 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
519 uart_write_wakeup(&uap->port);
520
521 return 1;
522 }
523
524 /*
525 * We received a transmit interrupt without a pending X-char but with
526 * pending characters.
527 * Locking: called with port lock held and IRQs disabled.
528 * Returns:
529 * false if we want to use PIO to transmit
530 * true if we queued a DMA buffer
531 */
pl011_dma_tx_irq(struct uart_amba_port * uap)532 static bool pl011_dma_tx_irq(struct uart_amba_port *uap)
533 {
534 if (!uap->using_tx_dma)
535 return false;
536
537 /*
538 * If we already have a TX buffer queued, but received a
539 * TX interrupt, it will be because we've just sent an X-char.
540 * Ensure the TX DMA is enabled and the TX IRQ is disabled.
541 */
542 if (uap->dmatx.queued) {
543 uap->dmacr |= UART011_TXDMAE;
544 writew(uap->dmacr, uap->port.membase + UART011_DMACR);
545 uap->im &= ~UART011_TXIM;
546 writew(uap->im, uap->port.membase + UART011_IMSC);
547 return true;
548 }
549
550 /*
551 * We don't have a TX buffer queued, so try to queue one.
552 * If we successfully queued a buffer, mask the TX IRQ.
553 */
554 if (pl011_dma_tx_refill(uap) > 0) {
555 uap->im &= ~UART011_TXIM;
556 writew(uap->im, uap->port.membase + UART011_IMSC);
557 return true;
558 }
559 return false;
560 }
561
562 /*
563 * Stop the DMA transmit (eg, due to received XOFF).
564 * Locking: called with port lock held and IRQs disabled.
565 */
pl011_dma_tx_stop(struct uart_amba_port * uap)566 static inline void pl011_dma_tx_stop(struct uart_amba_port *uap)
567 {
568 if (uap->dmatx.queued) {
569 uap->dmacr &= ~UART011_TXDMAE;
570 writew(uap->dmacr, uap->port.membase + UART011_DMACR);
571 }
572 }
573
574 /*
575 * Try to start a DMA transmit, or in the case of an XON/OFF
576 * character queued for send, try to get that character out ASAP.
577 * Locking: called with port lock held and IRQs disabled.
578 * Returns:
579 * false if we want the TX IRQ to be enabled
580 * true if we have a buffer queued
581 */
pl011_dma_tx_start(struct uart_amba_port * uap)582 static inline bool pl011_dma_tx_start(struct uart_amba_port *uap)
583 {
584 u16 dmacr;
585
586 if (!uap->using_tx_dma)
587 return false;
588
589 if (!uap->port.x_char) {
590 /* no X-char, try to push chars out in DMA mode */
591 bool ret = true;
592
593 if (!uap->dmatx.queued) {
594 if (pl011_dma_tx_refill(uap) > 0) {
595 uap->im &= ~UART011_TXIM;
596 ret = true;
597 } else {
598 uap->im |= UART011_TXIM;
599 ret = false;
600 }
601 writew(uap->im, uap->port.membase + UART011_IMSC);
602 } else if (!(uap->dmacr & UART011_TXDMAE)) {
603 uap->dmacr |= UART011_TXDMAE;
604 writew(uap->dmacr,
605 uap->port.membase + UART011_DMACR);
606 }
607 return ret;
608 }
609
610 /*
611 * We have an X-char to send. Disable DMA to prevent it loading
612 * the TX fifo, and then see if we can stuff it into the FIFO.
613 */
614 dmacr = uap->dmacr;
615 uap->dmacr &= ~UART011_TXDMAE;
616 writew(uap->dmacr, uap->port.membase + UART011_DMACR);
617
618 if (readw(uap->port.membase + UART01x_FR) & UART01x_FR_TXFF) {
619 /*
620 * No space in the FIFO, so enable the transmit interrupt
621 * so we know when there is space. Note that once we've
622 * loaded the character, we should just re-enable DMA.
623 */
624 return false;
625 }
626
627 writew(uap->port.x_char, uap->port.membase + UART01x_DR);
628 uap->port.icount.tx++;
629 uap->port.x_char = 0;
630
631 /* Success - restore the DMA state */
632 uap->dmacr = dmacr;
633 writew(dmacr, uap->port.membase + UART011_DMACR);
634
635 return true;
636 }
637
638 /*
639 * Flush the transmit buffer.
640 * Locking: called with port lock held and IRQs disabled.
641 */
pl011_dma_flush_buffer(struct uart_port * port)642 static void pl011_dma_flush_buffer(struct uart_port *port)
643 {
644 struct uart_amba_port *uap = (struct uart_amba_port *)port;
645
646 if (!uap->using_tx_dma)
647 return;
648
649 /* Avoid deadlock with the DMA engine callback */
650 spin_unlock(&uap->port.lock);
651 dmaengine_terminate_all(uap->dmatx.chan);
652 spin_lock(&uap->port.lock);
653 if (uap->dmatx.queued) {
654 dma_unmap_sg(uap->dmatx.chan->device->dev, &uap->dmatx.sg, 1,
655 DMA_TO_DEVICE);
656 uap->dmatx.queued = false;
657 uap->dmacr &= ~UART011_TXDMAE;
658 writew(uap->dmacr, uap->port.membase + UART011_DMACR);
659 }
660 }
661
662 static void pl011_dma_rx_callback(void *data);
663
pl011_dma_rx_trigger_dma(struct uart_amba_port * uap)664 static int pl011_dma_rx_trigger_dma(struct uart_amba_port *uap)
665 {
666 struct dma_chan *rxchan = uap->dmarx.chan;
667 struct dma_device *dma_dev;
668 struct pl011_dmarx_data *dmarx = &uap->dmarx;
669 struct dma_async_tx_descriptor *desc;
670 struct pl011_sgbuf *sgbuf;
671
672 if (!rxchan)
673 return -EIO;
674
675 /* Start the RX DMA job */
676 sgbuf = uap->dmarx.use_buf_b ?
677 &uap->dmarx.sgbuf_b : &uap->dmarx.sgbuf_a;
678 dma_dev = rxchan->device;
679 desc = rxchan->device->device_prep_slave_sg(rxchan, &sgbuf->sg, 1,
680 DMA_DEV_TO_MEM,
681 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
682 /*
683 * If the DMA engine is busy and cannot prepare a
684 * channel, no big deal, the driver will fall back
685 * to interrupt mode as a result of this error code.
686 */
687 if (!desc) {
688 uap->dmarx.running = false;
689 dmaengine_terminate_all(rxchan);
690 return -EBUSY;
691 }
692
693 /* Some data to go along to the callback */
694 desc->callback = pl011_dma_rx_callback;
695 desc->callback_param = uap;
696 dmarx->cookie = dmaengine_submit(desc);
697 dma_async_issue_pending(rxchan);
698
699 uap->dmacr |= UART011_RXDMAE;
700 writew(uap->dmacr, uap->port.membase + UART011_DMACR);
701 uap->dmarx.running = true;
702
703 uap->im &= ~UART011_RXIM;
704 writew(uap->im, uap->port.membase + UART011_IMSC);
705
706 return 0;
707 }
708
709 /*
710 * This is called when either the DMA job is complete, or
711 * the FIFO timeout interrupt occurred. This must be called
712 * with the port spinlock uap->port.lock held.
713 */
pl011_dma_rx_chars(struct uart_amba_port * uap,u32 pending,bool use_buf_b,bool readfifo)714 static void pl011_dma_rx_chars(struct uart_amba_port *uap,
715 u32 pending, bool use_buf_b,
716 bool readfifo)
717 {
718 struct tty_struct *tty = uap->port.state->port.tty;
719 struct pl011_sgbuf *sgbuf = use_buf_b ?
720 &uap->dmarx.sgbuf_b : &uap->dmarx.sgbuf_a;
721 struct device *dev = uap->dmarx.chan->device->dev;
722 int dma_count = 0;
723 u32 fifotaken = 0; /* only used for vdbg() */
724
725 /* Pick everything from the DMA first */
726 if (pending) {
727 /* Sync in buffer */
728 dma_sync_sg_for_cpu(dev, &sgbuf->sg, 1, DMA_FROM_DEVICE);
729
730 /*
731 * First take all chars in the DMA pipe, then look in the FIFO.
732 * Note that tty_insert_flip_buf() tries to take as many chars
733 * as it can.
734 */
735 dma_count = tty_insert_flip_string(uap->port.state->port.tty,
736 sgbuf->buf, pending);
737
738 /* Return buffer to device */
739 dma_sync_sg_for_device(dev, &sgbuf->sg, 1, DMA_FROM_DEVICE);
740
741 uap->port.icount.rx += dma_count;
742 if (dma_count < pending)
743 dev_warn(uap->port.dev,
744 "couldn't insert all characters (TTY is full?)\n");
745 }
746
747 /*
748 * Only continue with trying to read the FIFO if all DMA chars have
749 * been taken first.
750 */
751 if (dma_count == pending && readfifo) {
752 /* Clear any error flags */
753 writew(UART011_OEIS | UART011_BEIS | UART011_PEIS | UART011_FEIS,
754 uap->port.membase + UART011_ICR);
755
756 /*
757 * If we read all the DMA'd characters, and we had an
758 * incomplete buffer, that could be due to an rx error, or
759 * maybe we just timed out. Read any pending chars and check
760 * the error status.
761 *
762 * Error conditions will only occur in the FIFO, these will
763 * trigger an immediate interrupt and stop the DMA job, so we
764 * will always find the error in the FIFO, never in the DMA
765 * buffer.
766 */
767 fifotaken = pl011_fifo_to_tty(uap);
768 }
769
770 spin_unlock(&uap->port.lock);
771 dev_vdbg(uap->port.dev,
772 "Took %d chars from DMA buffer and %d chars from the FIFO\n",
773 dma_count, fifotaken);
774 tty_flip_buffer_push(tty);
775 spin_lock(&uap->port.lock);
776 }
777
pl011_dma_rx_irq(struct uart_amba_port * uap)778 static void pl011_dma_rx_irq(struct uart_amba_port *uap)
779 {
780 struct pl011_dmarx_data *dmarx = &uap->dmarx;
781 struct dma_chan *rxchan = dmarx->chan;
782 struct pl011_sgbuf *sgbuf = dmarx->use_buf_b ?
783 &dmarx->sgbuf_b : &dmarx->sgbuf_a;
784 size_t pending;
785 struct dma_tx_state state;
786 enum dma_status dmastat;
787
788 /*
789 * Pause the transfer so we can trust the current counter,
790 * do this before we pause the PL011 block, else we may
791 * overflow the FIFO.
792 */
793 if (dmaengine_pause(rxchan))
794 dev_err(uap->port.dev, "unable to pause DMA transfer\n");
795 dmastat = rxchan->device->device_tx_status(rxchan,
796 dmarx->cookie, &state);
797 if (dmastat != DMA_PAUSED)
798 dev_err(uap->port.dev, "unable to pause DMA transfer\n");
799
800 /* Disable RX DMA - incoming data will wait in the FIFO */
801 uap->dmacr &= ~UART011_RXDMAE;
802 writew(uap->dmacr, uap->port.membase + UART011_DMACR);
803 uap->dmarx.running = false;
804
805 pending = sgbuf->sg.length - state.residue;
806 BUG_ON(pending > PL011_DMA_BUFFER_SIZE);
807 /* Then we terminate the transfer - we now know our residue */
808 dmaengine_terminate_all(rxchan);
809
810 /*
811 * This will take the chars we have so far and insert
812 * into the framework.
813 */
814 pl011_dma_rx_chars(uap, pending, dmarx->use_buf_b, true);
815
816 /* Switch buffer & re-trigger DMA job */
817 dmarx->use_buf_b = !dmarx->use_buf_b;
818 if (pl011_dma_rx_trigger_dma(uap)) {
819 dev_dbg(uap->port.dev, "could not retrigger RX DMA job "
820 "fall back to interrupt mode\n");
821 uap->im |= UART011_RXIM;
822 writew(uap->im, uap->port.membase + UART011_IMSC);
823 }
824 }
825
pl011_dma_rx_callback(void * data)826 static void pl011_dma_rx_callback(void *data)
827 {
828 struct uart_amba_port *uap = data;
829 struct pl011_dmarx_data *dmarx = &uap->dmarx;
830 bool lastbuf = dmarx->use_buf_b;
831 int ret;
832
833 /*
834 * This completion interrupt occurs typically when the
835 * RX buffer is totally stuffed but no timeout has yet
836 * occurred. When that happens, we just want the RX
837 * routine to flush out the secondary DMA buffer while
838 * we immediately trigger the next DMA job.
839 */
840 spin_lock_irq(&uap->port.lock);
841 uap->dmarx.running = false;
842 dmarx->use_buf_b = !lastbuf;
843 ret = pl011_dma_rx_trigger_dma(uap);
844
845 pl011_dma_rx_chars(uap, PL011_DMA_BUFFER_SIZE, lastbuf, false);
846 spin_unlock_irq(&uap->port.lock);
847 /*
848 * Do this check after we picked the DMA chars so we don't
849 * get some IRQ immediately from RX.
850 */
851 if (ret) {
852 dev_dbg(uap->port.dev, "could not retrigger RX DMA job "
853 "fall back to interrupt mode\n");
854 uap->im |= UART011_RXIM;
855 writew(uap->im, uap->port.membase + UART011_IMSC);
856 }
857 }
858
859 /*
860 * Stop accepting received characters, when we're shutting down or
861 * suspending this port.
862 * Locking: called with port lock held and IRQs disabled.
863 */
pl011_dma_rx_stop(struct uart_amba_port * uap)864 static inline void pl011_dma_rx_stop(struct uart_amba_port *uap)
865 {
866 /* FIXME. Just disable the DMA enable */
867 uap->dmacr &= ~UART011_RXDMAE;
868 writew(uap->dmacr, uap->port.membase + UART011_DMACR);
869 }
870
pl011_dma_startup(struct uart_amba_port * uap)871 static void pl011_dma_startup(struct uart_amba_port *uap)
872 {
873 int ret;
874
875 if (!uap->dmatx.chan)
876 return;
877
878 uap->dmatx.buf = kmalloc(PL011_DMA_BUFFER_SIZE, GFP_KERNEL);
879 if (!uap->dmatx.buf) {
880 dev_err(uap->port.dev, "no memory for DMA TX buffer\n");
881 uap->port.fifosize = uap->fifosize;
882 return;
883 }
884
885 sg_init_one(&uap->dmatx.sg, uap->dmatx.buf, PL011_DMA_BUFFER_SIZE);
886
887 /* The DMA buffer is now the FIFO the TTY subsystem can use */
888 uap->port.fifosize = PL011_DMA_BUFFER_SIZE;
889 uap->using_tx_dma = true;
890
891 if (!uap->dmarx.chan)
892 goto skip_rx;
893
894 /* Allocate and map DMA RX buffers */
895 ret = pl011_sgbuf_init(uap->dmarx.chan, &uap->dmarx.sgbuf_a,
896 DMA_FROM_DEVICE);
897 if (ret) {
898 dev_err(uap->port.dev, "failed to init DMA %s: %d\n",
899 "RX buffer A", ret);
900 goto skip_rx;
901 }
902
903 ret = pl011_sgbuf_init(uap->dmarx.chan, &uap->dmarx.sgbuf_b,
904 DMA_FROM_DEVICE);
905 if (ret) {
906 dev_err(uap->port.dev, "failed to init DMA %s: %d\n",
907 "RX buffer B", ret);
908 pl011_sgbuf_free(uap->dmarx.chan, &uap->dmarx.sgbuf_a,
909 DMA_FROM_DEVICE);
910 goto skip_rx;
911 }
912
913 uap->using_rx_dma = true;
914
915 skip_rx:
916 /* Turn on DMA error (RX/TX will be enabled on demand) */
917 uap->dmacr |= UART011_DMAONERR;
918 writew(uap->dmacr, uap->port.membase + UART011_DMACR);
919
920 /*
921 * ST Micro variants has some specific dma burst threshold
922 * compensation. Set this to 16 bytes, so burst will only
923 * be issued above/below 16 bytes.
924 */
925 if (uap->vendor->dma_threshold)
926 writew(ST_UART011_DMAWM_RX_16 | ST_UART011_DMAWM_TX_16,
927 uap->port.membase + ST_UART011_DMAWM);
928
929 if (uap->using_rx_dma) {
930 if (pl011_dma_rx_trigger_dma(uap))
931 dev_dbg(uap->port.dev, "could not trigger initial "
932 "RX DMA job, fall back to interrupt mode\n");
933 }
934 }
935
pl011_dma_shutdown(struct uart_amba_port * uap)936 static void pl011_dma_shutdown(struct uart_amba_port *uap)
937 {
938 if (!(uap->using_tx_dma || uap->using_rx_dma))
939 return;
940
941 /* Disable RX and TX DMA */
942 while (readw(uap->port.membase + UART01x_FR) & UART01x_FR_BUSY)
943 barrier();
944
945 spin_lock_irq(&uap->port.lock);
946 uap->dmacr &= ~(UART011_DMAONERR | UART011_RXDMAE | UART011_TXDMAE);
947 writew(uap->dmacr, uap->port.membase + UART011_DMACR);
948 spin_unlock_irq(&uap->port.lock);
949
950 if (uap->using_tx_dma) {
951 /* In theory, this should already be done by pl011_dma_flush_buffer */
952 dmaengine_terminate_all(uap->dmatx.chan);
953 if (uap->dmatx.queued) {
954 dma_unmap_sg(uap->dmatx.chan->device->dev, &uap->dmatx.sg, 1,
955 DMA_TO_DEVICE);
956 uap->dmatx.queued = false;
957 }
958
959 kfree(uap->dmatx.buf);
960 uap->using_tx_dma = false;
961 }
962
963 if (uap->using_rx_dma) {
964 dmaengine_terminate_all(uap->dmarx.chan);
965 /* Clean up the RX DMA */
966 pl011_sgbuf_free(uap->dmarx.chan, &uap->dmarx.sgbuf_a, DMA_FROM_DEVICE);
967 pl011_sgbuf_free(uap->dmarx.chan, &uap->dmarx.sgbuf_b, DMA_FROM_DEVICE);
968 uap->using_rx_dma = false;
969 }
970 }
971
pl011_dma_rx_available(struct uart_amba_port * uap)972 static inline bool pl011_dma_rx_available(struct uart_amba_port *uap)
973 {
974 return uap->using_rx_dma;
975 }
976
pl011_dma_rx_running(struct uart_amba_port * uap)977 static inline bool pl011_dma_rx_running(struct uart_amba_port *uap)
978 {
979 return uap->using_rx_dma && uap->dmarx.running;
980 }
981
982
983 #else
984 /* Blank functions if the DMA engine is not available */
pl011_dma_probe(struct uart_amba_port * uap)985 static inline void pl011_dma_probe(struct uart_amba_port *uap)
986 {
987 }
988
pl011_dma_remove(struct uart_amba_port * uap)989 static inline void pl011_dma_remove(struct uart_amba_port *uap)
990 {
991 }
992
pl011_dma_startup(struct uart_amba_port * uap)993 static inline void pl011_dma_startup(struct uart_amba_port *uap)
994 {
995 }
996
pl011_dma_shutdown(struct uart_amba_port * uap)997 static inline void pl011_dma_shutdown(struct uart_amba_port *uap)
998 {
999 }
1000
pl011_dma_tx_irq(struct uart_amba_port * uap)1001 static inline bool pl011_dma_tx_irq(struct uart_amba_port *uap)
1002 {
1003 return false;
1004 }
1005
pl011_dma_tx_stop(struct uart_amba_port * uap)1006 static inline void pl011_dma_tx_stop(struct uart_amba_port *uap)
1007 {
1008 }
1009
pl011_dma_tx_start(struct uart_amba_port * uap)1010 static inline bool pl011_dma_tx_start(struct uart_amba_port *uap)
1011 {
1012 return false;
1013 }
1014
pl011_dma_rx_irq(struct uart_amba_port * uap)1015 static inline void pl011_dma_rx_irq(struct uart_amba_port *uap)
1016 {
1017 }
1018
pl011_dma_rx_stop(struct uart_amba_port * uap)1019 static inline void pl011_dma_rx_stop(struct uart_amba_port *uap)
1020 {
1021 }
1022
pl011_dma_rx_trigger_dma(struct uart_amba_port * uap)1023 static inline int pl011_dma_rx_trigger_dma(struct uart_amba_port *uap)
1024 {
1025 return -EIO;
1026 }
1027
pl011_dma_rx_available(struct uart_amba_port * uap)1028 static inline bool pl011_dma_rx_available(struct uart_amba_port *uap)
1029 {
1030 return false;
1031 }
1032
pl011_dma_rx_running(struct uart_amba_port * uap)1033 static inline bool pl011_dma_rx_running(struct uart_amba_port *uap)
1034 {
1035 return false;
1036 }
1037
1038 #define pl011_dma_flush_buffer NULL
1039 #endif
1040
1041
1042 /*
1043 * pl011_lockup_wa
1044 * This workaround aims to break the deadlock situation
1045 * when after long transfer over uart in hardware flow
1046 * control, uart interrupt registers cannot be cleared.
1047 * Hence uart transfer gets blocked.
1048 *
1049 * It is seen that during such deadlock condition ICR
1050 * don't get cleared even on multiple write. This leads
1051 * pass_counter to decrease and finally reach zero. This
1052 * can be taken as trigger point to run this UART_BT_WA.
1053 *
1054 */
pl011_lockup_wa(unsigned long data)1055 static void pl011_lockup_wa(unsigned long data)
1056 {
1057 struct uart_amba_port *uap = amba_ports[0];
1058 void __iomem *base = uap->port.membase;
1059 struct circ_buf *xmit = &uap->port.state->xmit;
1060 struct tty_struct *tty = uap->port.state->port.tty;
1061 int buf_empty_retries = 200;
1062 int loop;
1063
1064 /* Stop HCI layer from submitting data for tx */
1065 tty->hw_stopped = 1;
1066 while (!uart_circ_empty(xmit)) {
1067 if (buf_empty_retries-- == 0)
1068 break;
1069 udelay(100);
1070 }
1071
1072 /* Backup registers */
1073 for (loop = 0; loop < UART_WA_SAVE_NR; loop++)
1074 uart_wa_regdata[loop] = readl(base + uart_wa_reg[loop]);
1075
1076 /* Disable UART so that FIFO data is flushed out */
1077 writew(0x00, uap->port.membase + UART011_CR);
1078
1079 /* Soft reset UART module */
1080 if (uap->port.dev->platform_data) {
1081 struct amba_pl011_data *plat;
1082
1083 plat = uap->port.dev->platform_data;
1084 if (plat->reset)
1085 plat->reset();
1086 }
1087
1088 /* Restore registers */
1089 for (loop = 0; loop < UART_WA_SAVE_NR; loop++)
1090 writew(uart_wa_regdata[loop] ,
1091 uap->port.membase + uart_wa_reg[loop]);
1092
1093 /* Initialise the old status of the modem signals */
1094 uap->old_status = readw(uap->port.membase + UART01x_FR) &
1095 UART01x_FR_MODEM_ANY;
1096
1097 if (readl(base + UART011_MIS) & 0x2)
1098 printk(KERN_EMERG "UART_BT_WA: ***FAILED***\n");
1099
1100 /* Start Tx/Rx */
1101 tty->hw_stopped = 0;
1102 }
1103
pl011_stop_tx(struct uart_port * port)1104 static void pl011_stop_tx(struct uart_port *port)
1105 {
1106 struct uart_amba_port *uap = (struct uart_amba_port *)port;
1107
1108 uap->im &= ~UART011_TXIM;
1109 writew(uap->im, uap->port.membase + UART011_IMSC);
1110 pl011_dma_tx_stop(uap);
1111 }
1112
pl011_start_tx(struct uart_port * port)1113 static void pl011_start_tx(struct uart_port *port)
1114 {
1115 struct uart_amba_port *uap = (struct uart_amba_port *)port;
1116
1117 if (!pl011_dma_tx_start(uap)) {
1118 uap->im |= UART011_TXIM;
1119 writew(uap->im, uap->port.membase + UART011_IMSC);
1120 }
1121 }
1122
pl011_stop_rx(struct uart_port * port)1123 static void pl011_stop_rx(struct uart_port *port)
1124 {
1125 struct uart_amba_port *uap = (struct uart_amba_port *)port;
1126
1127 uap->im &= ~(UART011_RXIM|UART011_RTIM|UART011_FEIM|
1128 UART011_PEIM|UART011_BEIM|UART011_OEIM);
1129 writew(uap->im, uap->port.membase + UART011_IMSC);
1130
1131 pl011_dma_rx_stop(uap);
1132 }
1133
pl011_enable_ms(struct uart_port * port)1134 static void pl011_enable_ms(struct uart_port *port)
1135 {
1136 struct uart_amba_port *uap = (struct uart_amba_port *)port;
1137
1138 uap->im |= UART011_RIMIM|UART011_CTSMIM|UART011_DCDMIM|UART011_DSRMIM;
1139 writew(uap->im, uap->port.membase + UART011_IMSC);
1140 }
1141
pl011_rx_chars(struct uart_amba_port * uap)1142 static void pl011_rx_chars(struct uart_amba_port *uap)
1143 {
1144 struct tty_struct *tty = uap->port.state->port.tty;
1145
1146 pl011_fifo_to_tty(uap);
1147
1148 spin_unlock(&uap->port.lock);
1149 tty_flip_buffer_push(tty);
1150 /*
1151 * If we were temporarily out of DMA mode for a while,
1152 * attempt to switch back to DMA mode again.
1153 */
1154 if (pl011_dma_rx_available(uap)) {
1155 if (pl011_dma_rx_trigger_dma(uap)) {
1156 dev_dbg(uap->port.dev, "could not trigger RX DMA job "
1157 "fall back to interrupt mode again\n");
1158 uap->im |= UART011_RXIM;
1159 } else
1160 uap->im &= ~UART011_RXIM;
1161 writew(uap->im, uap->port.membase + UART011_IMSC);
1162 }
1163 spin_lock(&uap->port.lock);
1164 }
1165
pl011_tx_chars(struct uart_amba_port * uap)1166 static void pl011_tx_chars(struct uart_amba_port *uap)
1167 {
1168 struct circ_buf *xmit = &uap->port.state->xmit;
1169 int count;
1170
1171 if (uap->port.x_char) {
1172 writew(uap->port.x_char, uap->port.membase + UART01x_DR);
1173 uap->port.icount.tx++;
1174 uap->port.x_char = 0;
1175 return;
1176 }
1177 if (uart_circ_empty(xmit) || uart_tx_stopped(&uap->port)) {
1178 pl011_stop_tx(&uap->port);
1179 return;
1180 }
1181
1182 /* If we are using DMA mode, try to send some characters. */
1183 if (pl011_dma_tx_irq(uap))
1184 return;
1185
1186 count = uap->fifosize >> 1;
1187 do {
1188 writew(xmit->buf[xmit->tail], uap->port.membase + UART01x_DR);
1189 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
1190 uap->port.icount.tx++;
1191 if (uart_circ_empty(xmit))
1192 break;
1193 } while (--count > 0);
1194
1195 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
1196 uart_write_wakeup(&uap->port);
1197
1198 if (uart_circ_empty(xmit))
1199 pl011_stop_tx(&uap->port);
1200 }
1201
pl011_modem_status(struct uart_amba_port * uap)1202 static void pl011_modem_status(struct uart_amba_port *uap)
1203 {
1204 unsigned int status, delta;
1205
1206 status = readw(uap->port.membase + UART01x_FR) & UART01x_FR_MODEM_ANY;
1207
1208 delta = status ^ uap->old_status;
1209 uap->old_status = status;
1210
1211 if (!delta)
1212 return;
1213
1214 if (delta & UART01x_FR_DCD)
1215 uart_handle_dcd_change(&uap->port, status & UART01x_FR_DCD);
1216
1217 if (delta & UART01x_FR_DSR)
1218 uap->port.icount.dsr++;
1219
1220 if (delta & UART01x_FR_CTS)
1221 uart_handle_cts_change(&uap->port, status & UART01x_FR_CTS);
1222
1223 wake_up_interruptible(&uap->port.state->port.delta_msr_wait);
1224 }
1225
pl011_int(int irq,void * dev_id)1226 static irqreturn_t pl011_int(int irq, void *dev_id)
1227 {
1228 struct uart_amba_port *uap = dev_id;
1229 unsigned long flags;
1230 unsigned int status, pass_counter = AMBA_ISR_PASS_LIMIT;
1231 int handled = 0;
1232
1233 spin_lock_irqsave(&uap->port.lock, flags);
1234
1235 status = readw(uap->port.membase + UART011_MIS);
1236 if (status) {
1237 do {
1238 writew(status & ~(UART011_TXIS|UART011_RTIS|
1239 UART011_RXIS),
1240 uap->port.membase + UART011_ICR);
1241
1242 if (status & (UART011_RTIS|UART011_RXIS)) {
1243 if (pl011_dma_rx_running(uap))
1244 pl011_dma_rx_irq(uap);
1245 else
1246 pl011_rx_chars(uap);
1247 }
1248 if (status & (UART011_DSRMIS|UART011_DCDMIS|
1249 UART011_CTSMIS|UART011_RIMIS))
1250 pl011_modem_status(uap);
1251 if (status & UART011_TXIS)
1252 pl011_tx_chars(uap);
1253
1254 if (pass_counter-- == 0) {
1255 if (uap->interrupt_may_hang)
1256 tasklet_schedule(&pl011_lockup_tlet);
1257 break;
1258 }
1259
1260 status = readw(uap->port.membase + UART011_MIS);
1261 } while (status != 0);
1262 handled = 1;
1263 }
1264
1265 spin_unlock_irqrestore(&uap->port.lock, flags);
1266
1267 return IRQ_RETVAL(handled);
1268 }
1269
pl01x_tx_empty(struct uart_port * port)1270 static unsigned int pl01x_tx_empty(struct uart_port *port)
1271 {
1272 struct uart_amba_port *uap = (struct uart_amba_port *)port;
1273 unsigned int status = readw(uap->port.membase + UART01x_FR);
1274 return status & (UART01x_FR_BUSY|UART01x_FR_TXFF) ? 0 : TIOCSER_TEMT;
1275 }
1276
pl01x_get_mctrl(struct uart_port * port)1277 static unsigned int pl01x_get_mctrl(struct uart_port *port)
1278 {
1279 struct uart_amba_port *uap = (struct uart_amba_port *)port;
1280 unsigned int result = 0;
1281 unsigned int status = readw(uap->port.membase + UART01x_FR);
1282
1283 #define TIOCMBIT(uartbit, tiocmbit) \
1284 if (status & uartbit) \
1285 result |= tiocmbit
1286
1287 TIOCMBIT(UART01x_FR_DCD, TIOCM_CAR);
1288 TIOCMBIT(UART01x_FR_DSR, TIOCM_DSR);
1289 TIOCMBIT(UART01x_FR_CTS, TIOCM_CTS);
1290 TIOCMBIT(UART011_FR_RI, TIOCM_RNG);
1291 #undef TIOCMBIT
1292 return result;
1293 }
1294
pl011_set_mctrl(struct uart_port * port,unsigned int mctrl)1295 static void pl011_set_mctrl(struct uart_port *port, unsigned int mctrl)
1296 {
1297 struct uart_amba_port *uap = (struct uart_amba_port *)port;
1298 unsigned int cr;
1299
1300 cr = readw(uap->port.membase + UART011_CR);
1301
1302 #define TIOCMBIT(tiocmbit, uartbit) \
1303 if (mctrl & tiocmbit) \
1304 cr |= uartbit; \
1305 else \
1306 cr &= ~uartbit
1307
1308 TIOCMBIT(TIOCM_RTS, UART011_CR_RTS);
1309 TIOCMBIT(TIOCM_DTR, UART011_CR_DTR);
1310 TIOCMBIT(TIOCM_OUT1, UART011_CR_OUT1);
1311 TIOCMBIT(TIOCM_OUT2, UART011_CR_OUT2);
1312 TIOCMBIT(TIOCM_LOOP, UART011_CR_LBE);
1313
1314 if (uap->autorts) {
1315 /* We need to disable auto-RTS if we want to turn RTS off */
1316 TIOCMBIT(TIOCM_RTS, UART011_CR_RTSEN);
1317 }
1318 #undef TIOCMBIT
1319
1320 writew(cr, uap->port.membase + UART011_CR);
1321 }
1322
pl011_break_ctl(struct uart_port * port,int break_state)1323 static void pl011_break_ctl(struct uart_port *port, int break_state)
1324 {
1325 struct uart_amba_port *uap = (struct uart_amba_port *)port;
1326 unsigned long flags;
1327 unsigned int lcr_h;
1328
1329 spin_lock_irqsave(&uap->port.lock, flags);
1330 lcr_h = readw(uap->port.membase + uap->lcrh_tx);
1331 if (break_state == -1)
1332 lcr_h |= UART01x_LCRH_BRK;
1333 else
1334 lcr_h &= ~UART01x_LCRH_BRK;
1335 writew(lcr_h, uap->port.membase + uap->lcrh_tx);
1336 spin_unlock_irqrestore(&uap->port.lock, flags);
1337 }
1338
1339 #ifdef CONFIG_CONSOLE_POLL
pl010_get_poll_char(struct uart_port * port)1340 static int pl010_get_poll_char(struct uart_port *port)
1341 {
1342 struct uart_amba_port *uap = (struct uart_amba_port *)port;
1343 unsigned int status;
1344
1345 status = readw(uap->port.membase + UART01x_FR);
1346 if (status & UART01x_FR_RXFE)
1347 return NO_POLL_CHAR;
1348
1349 return readw(uap->port.membase + UART01x_DR);
1350 }
1351
pl010_put_poll_char(struct uart_port * port,unsigned char ch)1352 static void pl010_put_poll_char(struct uart_port *port,
1353 unsigned char ch)
1354 {
1355 struct uart_amba_port *uap = (struct uart_amba_port *)port;
1356
1357 while (readw(uap->port.membase + UART01x_FR) & UART01x_FR_TXFF)
1358 barrier();
1359
1360 writew(ch, uap->port.membase + UART01x_DR);
1361 }
1362
1363 #endif /* CONFIG_CONSOLE_POLL */
1364
pl011_startup(struct uart_port * port)1365 static int pl011_startup(struct uart_port *port)
1366 {
1367 struct uart_amba_port *uap = (struct uart_amba_port *)port;
1368 unsigned int cr;
1369 int retval;
1370
1371 retval = clk_prepare(uap->clk);
1372 if (retval)
1373 goto out;
1374
1375 /*
1376 * Try to enable the clock producer.
1377 */
1378 retval = clk_enable(uap->clk);
1379 if (retval)
1380 goto clk_unprep;
1381
1382 uap->port.uartclk = clk_get_rate(uap->clk);
1383
1384 /*
1385 * Allocate the IRQ
1386 */
1387 retval = request_irq(uap->port.irq, pl011_int, 0, "uart-pl011", uap);
1388 if (retval)
1389 goto clk_dis;
1390
1391 writew(uap->vendor->ifls, uap->port.membase + UART011_IFLS);
1392
1393 /*
1394 * Provoke TX FIFO interrupt into asserting.
1395 */
1396 cr = UART01x_CR_UARTEN | UART011_CR_TXE | UART011_CR_LBE;
1397 writew(cr, uap->port.membase + UART011_CR);
1398 writew(0, uap->port.membase + UART011_FBRD);
1399 writew(1, uap->port.membase + UART011_IBRD);
1400 writew(0, uap->port.membase + uap->lcrh_rx);
1401 if (uap->lcrh_tx != uap->lcrh_rx) {
1402 int i;
1403 /*
1404 * Wait 10 PCLKs before writing LCRH_TX register,
1405 * to get this delay write read only register 10 times
1406 */
1407 for (i = 0; i < 10; ++i)
1408 writew(0xff, uap->port.membase + UART011_MIS);
1409 writew(0, uap->port.membase + uap->lcrh_tx);
1410 }
1411 writew(0, uap->port.membase + UART01x_DR);
1412 while (readw(uap->port.membase + UART01x_FR) & UART01x_FR_BUSY)
1413 barrier();
1414
1415 /* restore RTS and DTR */
1416 cr = uap->old_cr & (UART011_CR_RTS | UART011_CR_DTR);
1417 cr |= UART01x_CR_UARTEN | UART011_CR_RXE | UART011_CR_TXE;
1418 writew(cr, uap->port.membase + UART011_CR);
1419
1420 /* Clear pending error interrupts */
1421 writew(UART011_OEIS | UART011_BEIS | UART011_PEIS | UART011_FEIS,
1422 uap->port.membase + UART011_ICR);
1423
1424 /*
1425 * initialise the old status of the modem signals
1426 */
1427 uap->old_status = readw(uap->port.membase + UART01x_FR) & UART01x_FR_MODEM_ANY;
1428
1429 /* Startup DMA */
1430 pl011_dma_startup(uap);
1431
1432 /*
1433 * Finally, enable interrupts, only timeouts when using DMA
1434 * if initial RX DMA job failed, start in interrupt mode
1435 * as well.
1436 */
1437 spin_lock_irq(&uap->port.lock);
1438 uap->im = UART011_RTIM;
1439 if (!pl011_dma_rx_running(uap))
1440 uap->im |= UART011_RXIM;
1441 writew(uap->im, uap->port.membase + UART011_IMSC);
1442 spin_unlock_irq(&uap->port.lock);
1443
1444 if (uap->port.dev->platform_data) {
1445 struct amba_pl011_data *plat;
1446
1447 plat = uap->port.dev->platform_data;
1448 if (plat->init)
1449 plat->init();
1450 }
1451
1452 return 0;
1453
1454 clk_dis:
1455 clk_disable(uap->clk);
1456 clk_unprep:
1457 clk_unprepare(uap->clk);
1458 out:
1459 return retval;
1460 }
1461
pl011_shutdown_channel(struct uart_amba_port * uap,unsigned int lcrh)1462 static void pl011_shutdown_channel(struct uart_amba_port *uap,
1463 unsigned int lcrh)
1464 {
1465 unsigned long val;
1466
1467 val = readw(uap->port.membase + lcrh);
1468 val &= ~(UART01x_LCRH_BRK | UART01x_LCRH_FEN);
1469 writew(val, uap->port.membase + lcrh);
1470 }
1471
pl011_shutdown(struct uart_port * port)1472 static void pl011_shutdown(struct uart_port *port)
1473 {
1474 struct uart_amba_port *uap = (struct uart_amba_port *)port;
1475 unsigned int cr;
1476
1477 /*
1478 * disable all interrupts
1479 */
1480 spin_lock_irq(&uap->port.lock);
1481 uap->im = 0;
1482 writew(uap->im, uap->port.membase + UART011_IMSC);
1483 writew(0xffff, uap->port.membase + UART011_ICR);
1484 spin_unlock_irq(&uap->port.lock);
1485
1486 pl011_dma_shutdown(uap);
1487
1488 /*
1489 * Free the interrupt
1490 */
1491 free_irq(uap->port.irq, uap);
1492
1493 /*
1494 * disable the port
1495 * disable the port. It should not disable RTS and DTR.
1496 * Also RTS and DTR state should be preserved to restore
1497 * it during startup().
1498 */
1499 uap->autorts = false;
1500 cr = readw(uap->port.membase + UART011_CR);
1501 uap->old_cr = cr;
1502 cr &= UART011_CR_RTS | UART011_CR_DTR;
1503 cr |= UART01x_CR_UARTEN | UART011_CR_TXE;
1504 writew(cr, uap->port.membase + UART011_CR);
1505
1506 /*
1507 * disable break condition and fifos
1508 */
1509 pl011_shutdown_channel(uap, uap->lcrh_rx);
1510 if (uap->lcrh_rx != uap->lcrh_tx)
1511 pl011_shutdown_channel(uap, uap->lcrh_tx);
1512
1513 /*
1514 * Shut down the clock producer
1515 */
1516 clk_disable(uap->clk);
1517 clk_unprepare(uap->clk);
1518
1519 if (uap->port.dev->platform_data) {
1520 struct amba_pl011_data *plat;
1521
1522 plat = uap->port.dev->platform_data;
1523 if (plat->exit)
1524 plat->exit();
1525 }
1526
1527 }
1528
1529 static void
pl011_set_termios(struct uart_port * port,struct ktermios * termios,struct ktermios * old)1530 pl011_set_termios(struct uart_port *port, struct ktermios *termios,
1531 struct ktermios *old)
1532 {
1533 struct uart_amba_port *uap = (struct uart_amba_port *)port;
1534 unsigned int lcr_h, old_cr;
1535 unsigned long flags;
1536 unsigned int baud, quot, clkdiv;
1537
1538 if (uap->vendor->oversampling)
1539 clkdiv = 8;
1540 else
1541 clkdiv = 16;
1542
1543 /*
1544 * Ask the core to calculate the divisor for us.
1545 */
1546 baud = uart_get_baud_rate(port, termios, old, 0,
1547 port->uartclk / clkdiv);
1548
1549 if (baud > port->uartclk/16)
1550 quot = DIV_ROUND_CLOSEST(port->uartclk * 8, baud);
1551 else
1552 quot = DIV_ROUND_CLOSEST(port->uartclk * 4, baud);
1553
1554 switch (termios->c_cflag & CSIZE) {
1555 case CS5:
1556 lcr_h = UART01x_LCRH_WLEN_5;
1557 break;
1558 case CS6:
1559 lcr_h = UART01x_LCRH_WLEN_6;
1560 break;
1561 case CS7:
1562 lcr_h = UART01x_LCRH_WLEN_7;
1563 break;
1564 default: // CS8
1565 lcr_h = UART01x_LCRH_WLEN_8;
1566 break;
1567 }
1568 if (termios->c_cflag & CSTOPB)
1569 lcr_h |= UART01x_LCRH_STP2;
1570 if (termios->c_cflag & PARENB) {
1571 lcr_h |= UART01x_LCRH_PEN;
1572 if (!(termios->c_cflag & PARODD))
1573 lcr_h |= UART01x_LCRH_EPS;
1574 }
1575 if (uap->fifosize > 1)
1576 lcr_h |= UART01x_LCRH_FEN;
1577
1578 spin_lock_irqsave(&port->lock, flags);
1579
1580 /*
1581 * Update the per-port timeout.
1582 */
1583 uart_update_timeout(port, termios->c_cflag, baud);
1584
1585 port->read_status_mask = UART011_DR_OE | 255;
1586 if (termios->c_iflag & INPCK)
1587 port->read_status_mask |= UART011_DR_FE | UART011_DR_PE;
1588 if (termios->c_iflag & (BRKINT | PARMRK))
1589 port->read_status_mask |= UART011_DR_BE;
1590
1591 /*
1592 * Characters to ignore
1593 */
1594 port->ignore_status_mask = 0;
1595 if (termios->c_iflag & IGNPAR)
1596 port->ignore_status_mask |= UART011_DR_FE | UART011_DR_PE;
1597 if (termios->c_iflag & IGNBRK) {
1598 port->ignore_status_mask |= UART011_DR_BE;
1599 /*
1600 * If we're ignoring parity and break indicators,
1601 * ignore overruns too (for real raw support).
1602 */
1603 if (termios->c_iflag & IGNPAR)
1604 port->ignore_status_mask |= UART011_DR_OE;
1605 }
1606
1607 /*
1608 * Ignore all characters if CREAD is not set.
1609 */
1610 if ((termios->c_cflag & CREAD) == 0)
1611 port->ignore_status_mask |= UART_DUMMY_DR_RX;
1612
1613 if (UART_ENABLE_MS(port, termios->c_cflag))
1614 pl011_enable_ms(port);
1615
1616 /* first, disable everything */
1617 old_cr = readw(port->membase + UART011_CR);
1618 writew(0, port->membase + UART011_CR);
1619
1620 if (termios->c_cflag & CRTSCTS) {
1621 if (old_cr & UART011_CR_RTS)
1622 old_cr |= UART011_CR_RTSEN;
1623
1624 old_cr |= UART011_CR_CTSEN;
1625 uap->autorts = true;
1626 } else {
1627 old_cr &= ~(UART011_CR_CTSEN | UART011_CR_RTSEN);
1628 uap->autorts = false;
1629 }
1630
1631 if (uap->vendor->oversampling) {
1632 if (baud > port->uartclk / 16)
1633 old_cr |= ST_UART011_CR_OVSFACT;
1634 else
1635 old_cr &= ~ST_UART011_CR_OVSFACT;
1636 }
1637
1638 /* Set baud rate */
1639 writew(quot & 0x3f, port->membase + UART011_FBRD);
1640 writew(quot >> 6, port->membase + UART011_IBRD);
1641
1642 /*
1643 * ----------v----------v----------v----------v-----
1644 * NOTE: MUST BE WRITTEN AFTER UARTLCR_M & UARTLCR_L
1645 * ----------^----------^----------^----------^-----
1646 */
1647 writew(lcr_h, port->membase + uap->lcrh_rx);
1648 if (uap->lcrh_rx != uap->lcrh_tx) {
1649 int i;
1650 /*
1651 * Wait 10 PCLKs before writing LCRH_TX register,
1652 * to get this delay write read only register 10 times
1653 */
1654 for (i = 0; i < 10; ++i)
1655 writew(0xff, uap->port.membase + UART011_MIS);
1656 writew(lcr_h, port->membase + uap->lcrh_tx);
1657 }
1658 writew(old_cr, port->membase + UART011_CR);
1659
1660 spin_unlock_irqrestore(&port->lock, flags);
1661 }
1662
pl011_type(struct uart_port * port)1663 static const char *pl011_type(struct uart_port *port)
1664 {
1665 struct uart_amba_port *uap = (struct uart_amba_port *)port;
1666 return uap->port.type == PORT_AMBA ? uap->type : NULL;
1667 }
1668
1669 /*
1670 * Release the memory region(s) being used by 'port'
1671 */
pl010_release_port(struct uart_port * port)1672 static void pl010_release_port(struct uart_port *port)
1673 {
1674 release_mem_region(port->mapbase, SZ_4K);
1675 }
1676
1677 /*
1678 * Request the memory region(s) being used by 'port'
1679 */
pl010_request_port(struct uart_port * port)1680 static int pl010_request_port(struct uart_port *port)
1681 {
1682 return request_mem_region(port->mapbase, SZ_4K, "uart-pl011")
1683 != NULL ? 0 : -EBUSY;
1684 }
1685
1686 /*
1687 * Configure/autoconfigure the port.
1688 */
pl010_config_port(struct uart_port * port,int flags)1689 static void pl010_config_port(struct uart_port *port, int flags)
1690 {
1691 if (flags & UART_CONFIG_TYPE) {
1692 port->type = PORT_AMBA;
1693 pl010_request_port(port);
1694 }
1695 }
1696
1697 /*
1698 * verify the new serial_struct (for TIOCSSERIAL).
1699 */
pl010_verify_port(struct uart_port * port,struct serial_struct * ser)1700 static int pl010_verify_port(struct uart_port *port, struct serial_struct *ser)
1701 {
1702 int ret = 0;
1703 if (ser->type != PORT_UNKNOWN && ser->type != PORT_AMBA)
1704 ret = -EINVAL;
1705 if (ser->irq < 0 || ser->irq >= nr_irqs)
1706 ret = -EINVAL;
1707 if (ser->baud_base < 9600)
1708 ret = -EINVAL;
1709 return ret;
1710 }
1711
1712 static struct uart_ops amba_pl011_pops = {
1713 .tx_empty = pl01x_tx_empty,
1714 .set_mctrl = pl011_set_mctrl,
1715 .get_mctrl = pl01x_get_mctrl,
1716 .stop_tx = pl011_stop_tx,
1717 .start_tx = pl011_start_tx,
1718 .stop_rx = pl011_stop_rx,
1719 .enable_ms = pl011_enable_ms,
1720 .break_ctl = pl011_break_ctl,
1721 .startup = pl011_startup,
1722 .shutdown = pl011_shutdown,
1723 .flush_buffer = pl011_dma_flush_buffer,
1724 .set_termios = pl011_set_termios,
1725 .type = pl011_type,
1726 .release_port = pl010_release_port,
1727 .request_port = pl010_request_port,
1728 .config_port = pl010_config_port,
1729 .verify_port = pl010_verify_port,
1730 #ifdef CONFIG_CONSOLE_POLL
1731 .poll_get_char = pl010_get_poll_char,
1732 .poll_put_char = pl010_put_poll_char,
1733 #endif
1734 };
1735
1736 static struct uart_amba_port *amba_ports[UART_NR];
1737
1738 #ifdef CONFIG_SERIAL_AMBA_PL011_CONSOLE
1739
pl011_console_putchar(struct uart_port * port,int ch)1740 static void pl011_console_putchar(struct uart_port *port, int ch)
1741 {
1742 struct uart_amba_port *uap = (struct uart_amba_port *)port;
1743
1744 while (readw(uap->port.membase + UART01x_FR) & UART01x_FR_TXFF)
1745 barrier();
1746 writew(ch, uap->port.membase + UART01x_DR);
1747 }
1748
1749 static void
pl011_console_write(struct console * co,const char * s,unsigned int count)1750 pl011_console_write(struct console *co, const char *s, unsigned int count)
1751 {
1752 struct uart_amba_port *uap = amba_ports[co->index];
1753 unsigned int status, old_cr, new_cr;
1754 unsigned long flags;
1755 int locked = 1;
1756
1757 clk_enable(uap->clk);
1758
1759 local_irq_save(flags);
1760 if (uap->port.sysrq)
1761 locked = 0;
1762 else if (oops_in_progress)
1763 locked = spin_trylock(&uap->port.lock);
1764 else
1765 spin_lock(&uap->port.lock);
1766
1767 /*
1768 * First save the CR then disable the interrupts
1769 */
1770 old_cr = readw(uap->port.membase + UART011_CR);
1771 new_cr = old_cr & ~UART011_CR_CTSEN;
1772 new_cr |= UART01x_CR_UARTEN | UART011_CR_TXE;
1773 writew(new_cr, uap->port.membase + UART011_CR);
1774
1775 uart_console_write(&uap->port, s, count, pl011_console_putchar);
1776
1777 /*
1778 * Finally, wait for transmitter to become empty
1779 * and restore the TCR
1780 */
1781 do {
1782 status = readw(uap->port.membase + UART01x_FR);
1783 } while (status & UART01x_FR_BUSY);
1784 writew(old_cr, uap->port.membase + UART011_CR);
1785
1786 if (locked)
1787 spin_unlock(&uap->port.lock);
1788 local_irq_restore(flags);
1789
1790 clk_disable(uap->clk);
1791 }
1792
1793 static void __init
pl011_console_get_options(struct uart_amba_port * uap,int * baud,int * parity,int * bits)1794 pl011_console_get_options(struct uart_amba_port *uap, int *baud,
1795 int *parity, int *bits)
1796 {
1797 if (readw(uap->port.membase + UART011_CR) & UART01x_CR_UARTEN) {
1798 unsigned int lcr_h, ibrd, fbrd;
1799
1800 lcr_h = readw(uap->port.membase + uap->lcrh_tx);
1801
1802 *parity = 'n';
1803 if (lcr_h & UART01x_LCRH_PEN) {
1804 if (lcr_h & UART01x_LCRH_EPS)
1805 *parity = 'e';
1806 else
1807 *parity = 'o';
1808 }
1809
1810 if ((lcr_h & 0x60) == UART01x_LCRH_WLEN_7)
1811 *bits = 7;
1812 else
1813 *bits = 8;
1814
1815 ibrd = readw(uap->port.membase + UART011_IBRD);
1816 fbrd = readw(uap->port.membase + UART011_FBRD);
1817
1818 *baud = uap->port.uartclk * 4 / (64 * ibrd + fbrd);
1819
1820 if (uap->vendor->oversampling) {
1821 if (readw(uap->port.membase + UART011_CR)
1822 & ST_UART011_CR_OVSFACT)
1823 *baud *= 2;
1824 }
1825 }
1826 }
1827
pl011_console_setup(struct console * co,char * options)1828 static int __init pl011_console_setup(struct console *co, char *options)
1829 {
1830 struct uart_amba_port *uap;
1831 int baud = 38400;
1832 int bits = 8;
1833 int parity = 'n';
1834 int flow = 'n';
1835 int ret;
1836
1837 /*
1838 * Check whether an invalid uart number has been specified, and
1839 * if so, search for the first available port that does have
1840 * console support.
1841 */
1842 if (co->index >= UART_NR)
1843 co->index = 0;
1844 uap = amba_ports[co->index];
1845 if (!uap)
1846 return -ENODEV;
1847
1848 ret = clk_prepare(uap->clk);
1849 if (ret)
1850 return ret;
1851
1852 if (uap->port.dev->platform_data) {
1853 struct amba_pl011_data *plat;
1854
1855 plat = uap->port.dev->platform_data;
1856 if (plat->init)
1857 plat->init();
1858 }
1859
1860 uap->port.uartclk = clk_get_rate(uap->clk);
1861
1862 if (options)
1863 uart_parse_options(options, &baud, &parity, &bits, &flow);
1864 else
1865 pl011_console_get_options(uap, &baud, &parity, &bits);
1866
1867 return uart_set_options(&uap->port, co, baud, parity, bits, flow);
1868 }
1869
1870 static struct uart_driver amba_reg;
1871 static struct console amba_console = {
1872 .name = "ttyAMA",
1873 .write = pl011_console_write,
1874 .device = uart_console_device,
1875 .setup = pl011_console_setup,
1876 .flags = CON_PRINTBUFFER,
1877 .index = -1,
1878 .data = &amba_reg,
1879 };
1880
1881 #define AMBA_CONSOLE (&amba_console)
1882 #else
1883 #define AMBA_CONSOLE NULL
1884 #endif
1885
1886 static struct uart_driver amba_reg = {
1887 .owner = THIS_MODULE,
1888 .driver_name = "ttyAMA",
1889 .dev_name = "ttyAMA",
1890 .major = SERIAL_AMBA_MAJOR,
1891 .minor = SERIAL_AMBA_MINOR,
1892 .nr = UART_NR,
1893 .cons = AMBA_CONSOLE,
1894 };
1895
pl011_probe(struct amba_device * dev,const struct amba_id * id)1896 static int pl011_probe(struct amba_device *dev, const struct amba_id *id)
1897 {
1898 struct uart_amba_port *uap;
1899 struct vendor_data *vendor = id->data;
1900 void __iomem *base;
1901 int i, ret;
1902
1903 for (i = 0; i < ARRAY_SIZE(amba_ports); i++)
1904 if (amba_ports[i] == NULL)
1905 break;
1906
1907 if (i == ARRAY_SIZE(amba_ports)) {
1908 ret = -EBUSY;
1909 goto out;
1910 }
1911
1912 uap = kzalloc(sizeof(struct uart_amba_port), GFP_KERNEL);
1913 if (uap == NULL) {
1914 ret = -ENOMEM;
1915 goto out;
1916 }
1917
1918 base = ioremap(dev->res.start, resource_size(&dev->res));
1919 if (!base) {
1920 ret = -ENOMEM;
1921 goto free;
1922 }
1923
1924 uap->clk = clk_get(&dev->dev, NULL);
1925 if (IS_ERR(uap->clk)) {
1926 ret = PTR_ERR(uap->clk);
1927 goto unmap;
1928 }
1929
1930 uap->vendor = vendor;
1931 uap->lcrh_rx = vendor->lcrh_rx;
1932 uap->lcrh_tx = vendor->lcrh_tx;
1933 uap->old_cr = 0;
1934 uap->fifosize = vendor->fifosize;
1935 uap->interrupt_may_hang = vendor->interrupt_may_hang;
1936 uap->port.dev = &dev->dev;
1937 uap->port.mapbase = dev->res.start;
1938 uap->port.membase = base;
1939 uap->port.iotype = UPIO_MEM;
1940 uap->port.irq = dev->irq[0];
1941 uap->port.fifosize = uap->fifosize;
1942 uap->port.ops = &amba_pl011_pops;
1943 uap->port.flags = UPF_BOOT_AUTOCONF;
1944 uap->port.line = i;
1945 pl011_dma_probe(uap);
1946
1947 snprintf(uap->type, sizeof(uap->type), "PL011 rev%u", amba_rev(dev));
1948
1949 amba_ports[i] = uap;
1950
1951 amba_set_drvdata(dev, uap);
1952 ret = uart_add_one_port(&amba_reg, &uap->port);
1953 if (ret) {
1954 amba_set_drvdata(dev, NULL);
1955 amba_ports[i] = NULL;
1956 pl011_dma_remove(uap);
1957 clk_put(uap->clk);
1958 unmap:
1959 iounmap(base);
1960 free:
1961 kfree(uap);
1962 }
1963 out:
1964 return ret;
1965 }
1966
pl011_remove(struct amba_device * dev)1967 static int pl011_remove(struct amba_device *dev)
1968 {
1969 struct uart_amba_port *uap = amba_get_drvdata(dev);
1970 int i;
1971
1972 amba_set_drvdata(dev, NULL);
1973
1974 uart_remove_one_port(&amba_reg, &uap->port);
1975
1976 for (i = 0; i < ARRAY_SIZE(amba_ports); i++)
1977 if (amba_ports[i] == uap)
1978 amba_ports[i] = NULL;
1979
1980 pl011_dma_remove(uap);
1981 iounmap(uap->port.membase);
1982 clk_put(uap->clk);
1983 kfree(uap);
1984 return 0;
1985 }
1986
1987 #ifdef CONFIG_PM
pl011_suspend(struct amba_device * dev,pm_message_t state)1988 static int pl011_suspend(struct amba_device *dev, pm_message_t state)
1989 {
1990 struct uart_amba_port *uap = amba_get_drvdata(dev);
1991
1992 if (!uap)
1993 return -EINVAL;
1994
1995 return uart_suspend_port(&amba_reg, &uap->port);
1996 }
1997
pl011_resume(struct amba_device * dev)1998 static int pl011_resume(struct amba_device *dev)
1999 {
2000 struct uart_amba_port *uap = amba_get_drvdata(dev);
2001
2002 if (!uap)
2003 return -EINVAL;
2004
2005 return uart_resume_port(&amba_reg, &uap->port);
2006 }
2007 #endif
2008
2009 static struct amba_id pl011_ids[] = {
2010 {
2011 .id = 0x00041011,
2012 .mask = 0x000fffff,
2013 .data = &vendor_arm,
2014 },
2015 {
2016 .id = 0x00380802,
2017 .mask = 0x00ffffff,
2018 .data = &vendor_st,
2019 },
2020 { 0, 0 },
2021 };
2022
2023 MODULE_DEVICE_TABLE(amba, pl011_ids);
2024
2025 static struct amba_driver pl011_driver = {
2026 .drv = {
2027 .name = "uart-pl011",
2028 },
2029 .id_table = pl011_ids,
2030 .probe = pl011_probe,
2031 .remove = pl011_remove,
2032 #ifdef CONFIG_PM
2033 .suspend = pl011_suspend,
2034 .resume = pl011_resume,
2035 #endif
2036 };
2037
pl011_init(void)2038 static int __init pl011_init(void)
2039 {
2040 int ret;
2041 printk(KERN_INFO "Serial: AMBA PL011 UART driver\n");
2042
2043 ret = uart_register_driver(&amba_reg);
2044 if (ret == 0) {
2045 ret = amba_driver_register(&pl011_driver);
2046 if (ret)
2047 uart_unregister_driver(&amba_reg);
2048 }
2049 return ret;
2050 }
2051
pl011_exit(void)2052 static void __exit pl011_exit(void)
2053 {
2054 amba_driver_unregister(&pl011_driver);
2055 uart_unregister_driver(&amba_reg);
2056 }
2057
2058 /*
2059 * While this can be a module, if builtin it's most likely the console
2060 * So let's leave module_exit but move module_init to an earlier place
2061 */
2062 arch_initcall(pl011_init);
2063 module_exit(pl011_exit);
2064
2065 MODULE_AUTHOR("ARM Ltd/Deep Blue Solutions Ltd");
2066 MODULE_DESCRIPTION("ARM AMBA serial port driver");
2067 MODULE_LICENSE("GPL");
2068