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1da177e4 | 1 | /* |
1da177e4 LT |
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. | |
68b65f73 | 8 | * Copyright (C) 2010 ST-Ericsson SA |
1da177e4 LT |
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 | * | |
1da177e4 LT |
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 | */ | |
1da177e4 LT |
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> | |
a62c80e5 RK |
46 | #include <linux/amba/bus.h> |
47 | #include <linux/amba/serial.h> | |
f8ce2547 | 48 | #include <linux/clk.h> |
5a0e3ad6 | 49 | #include <linux/slab.h> |
68b65f73 RK |
50 | #include <linux/dmaengine.h> |
51 | #include <linux/dma-mapping.h> | |
52 | #include <linux/scatterlist.h> | |
c16d51a3 | 53 | #include <linux/delay.h> |
258aea76 | 54 | #include <linux/types.h> |
258e0551 | 55 | #include <linux/pinctrl/consumer.h> |
1da177e4 LT |
56 | |
57 | #include <asm/io.h> | |
c6b8fdad | 58 | #include <asm/sizes.h> |
1da177e4 LT |
59 | |
60 | #define UART_NR 14 | |
61 | ||
62 | #define SERIAL_AMBA_MAJOR 204 | |
63 | #define SERIAL_AMBA_MINOR 64 | |
64 | #define SERIAL_AMBA_NR UART_NR | |
65 | ||
66 | #define AMBA_ISR_PASS_LIMIT 256 | |
67 | ||
b63d4f0f RK |
68 | #define UART_DR_ERROR (UART011_DR_OE|UART011_DR_BE|UART011_DR_PE|UART011_DR_FE) |
69 | #define UART_DUMMY_DR_RX (1 << 16) | |
1da177e4 | 70 | |
5926a295 AR |
71 | /* There is by now at least one vendor with differing details, so handle it */ |
72 | struct vendor_data { | |
73 | unsigned int ifls; | |
74 | unsigned int fifosize; | |
ec489aa8 LW |
75 | unsigned int lcrh_tx; |
76 | unsigned int lcrh_rx; | |
ac3e3fb4 | 77 | bool oversampling; |
c16d51a3 | 78 | bool interrupt_may_hang; /* vendor-specific */ |
38d62436 | 79 | bool dma_threshold; |
4fd0690b | 80 | bool cts_event_workaround; |
5926a295 AR |
81 | }; |
82 | ||
83 | static struct vendor_data vendor_arm = { | |
84 | .ifls = UART011_IFLS_RX4_8|UART011_IFLS_TX4_8, | |
85 | .fifosize = 16, | |
ec489aa8 LW |
86 | .lcrh_tx = UART011_LCRH, |
87 | .lcrh_rx = UART011_LCRH, | |
ac3e3fb4 | 88 | .oversampling = false, |
38d62436 | 89 | .dma_threshold = false, |
4fd0690b | 90 | .cts_event_workaround = false, |
5926a295 AR |
91 | }; |
92 | ||
93 | static struct vendor_data vendor_st = { | |
94 | .ifls = UART011_IFLS_RX_HALF|UART011_IFLS_TX_HALF, | |
95 | .fifosize = 64, | |
ec489aa8 LW |
96 | .lcrh_tx = ST_UART011_LCRH_TX, |
97 | .lcrh_rx = ST_UART011_LCRH_RX, | |
ac3e3fb4 | 98 | .oversampling = true, |
c16d51a3 | 99 | .interrupt_may_hang = true, |
38d62436 | 100 | .dma_threshold = true, |
4fd0690b | 101 | .cts_event_workaround = true, |
1da177e4 LT |
102 | }; |
103 | ||
c16d51a3 SKS |
104 | static struct uart_amba_port *amba_ports[UART_NR]; |
105 | ||
68b65f73 | 106 | /* Deals with DMA transactions */ |
ead76f32 LW |
107 | |
108 | struct pl011_sgbuf { | |
109 | struct scatterlist sg; | |
110 | char *buf; | |
111 | }; | |
112 | ||
113 | struct pl011_dmarx_data { | |
114 | struct dma_chan *chan; | |
115 | struct completion complete; | |
116 | bool use_buf_b; | |
117 | struct pl011_sgbuf sgbuf_a; | |
118 | struct pl011_sgbuf sgbuf_b; | |
119 | dma_cookie_t cookie; | |
120 | bool running; | |
121 | }; | |
122 | ||
68b65f73 RK |
123 | struct pl011_dmatx_data { |
124 | struct dma_chan *chan; | |
125 | struct scatterlist sg; | |
126 | char *buf; | |
127 | bool queued; | |
128 | }; | |
129 | ||
c19f12b5 RK |
130 | /* |
131 | * We wrap our port structure around the generic uart_port. | |
132 | */ | |
133 | struct uart_amba_port { | |
134 | struct uart_port port; | |
135 | struct clk *clk; | |
136 | const struct vendor_data *vendor; | |
68b65f73 | 137 | unsigned int dmacr; /* dma control reg */ |
c19f12b5 RK |
138 | unsigned int im; /* interrupt mask */ |
139 | unsigned int old_status; | |
ffca2b11 | 140 | unsigned int fifosize; /* vendor-specific */ |
c19f12b5 RK |
141 | unsigned int lcrh_tx; /* vendor-specific */ |
142 | unsigned int lcrh_rx; /* vendor-specific */ | |
d8d8ffa4 | 143 | unsigned int old_cr; /* state during shutdown */ |
c19f12b5 RK |
144 | bool autorts; |
145 | char type[12]; | |
c16d51a3 | 146 | bool interrupt_may_hang; /* vendor-specific */ |
68b65f73 RK |
147 | #ifdef CONFIG_DMA_ENGINE |
148 | /* DMA stuff */ | |
ead76f32 LW |
149 | bool using_tx_dma; |
150 | bool using_rx_dma; | |
151 | struct pl011_dmarx_data dmarx; | |
68b65f73 RK |
152 | struct pl011_dmatx_data dmatx; |
153 | #endif | |
154 | }; | |
155 | ||
29772c4e LW |
156 | /* |
157 | * Reads up to 256 characters from the FIFO or until it's empty and | |
158 | * inserts them into the TTY layer. Returns the number of characters | |
159 | * read from the FIFO. | |
160 | */ | |
161 | static int pl011_fifo_to_tty(struct uart_amba_port *uap) | |
162 | { | |
163 | u16 status, ch; | |
164 | unsigned int flag, max_count = 256; | |
165 | int fifotaken = 0; | |
166 | ||
167 | while (max_count--) { | |
168 | status = readw(uap->port.membase + UART01x_FR); | |
169 | if (status & UART01x_FR_RXFE) | |
170 | break; | |
171 | ||
172 | /* Take chars from the FIFO and update status */ | |
173 | ch = readw(uap->port.membase + UART01x_DR) | | |
174 | UART_DUMMY_DR_RX; | |
175 | flag = TTY_NORMAL; | |
176 | uap->port.icount.rx++; | |
177 | fifotaken++; | |
178 | ||
179 | if (unlikely(ch & UART_DR_ERROR)) { | |
180 | if (ch & UART011_DR_BE) { | |
181 | ch &= ~(UART011_DR_FE | UART011_DR_PE); | |
182 | uap->port.icount.brk++; | |
183 | if (uart_handle_break(&uap->port)) | |
184 | continue; | |
185 | } else if (ch & UART011_DR_PE) | |
186 | uap->port.icount.parity++; | |
187 | else if (ch & UART011_DR_FE) | |
188 | uap->port.icount.frame++; | |
189 | if (ch & UART011_DR_OE) | |
190 | uap->port.icount.overrun++; | |
191 | ||
192 | ch &= uap->port.read_status_mask; | |
193 | ||
194 | if (ch & UART011_DR_BE) | |
195 | flag = TTY_BREAK; | |
196 | else if (ch & UART011_DR_PE) | |
197 | flag = TTY_PARITY; | |
198 | else if (ch & UART011_DR_FE) | |
199 | flag = TTY_FRAME; | |
200 | } | |
201 | ||
202 | if (uart_handle_sysrq_char(&uap->port, ch & 255)) | |
203 | continue; | |
204 | ||
205 | uart_insert_char(&uap->port, ch, UART011_DR_OE, ch, flag); | |
206 | } | |
207 | ||
208 | return fifotaken; | |
209 | } | |
210 | ||
211 | ||
68b65f73 RK |
212 | /* |
213 | * All the DMA operation mode stuff goes inside this ifdef. | |
214 | * This assumes that you have a generic DMA device interface, | |
215 | * no custom DMA interfaces are supported. | |
216 | */ | |
217 | #ifdef CONFIG_DMA_ENGINE | |
218 | ||
219 | #define PL011_DMA_BUFFER_SIZE PAGE_SIZE | |
220 | ||
ead76f32 LW |
221 | static int pl011_sgbuf_init(struct dma_chan *chan, struct pl011_sgbuf *sg, |
222 | enum dma_data_direction dir) | |
223 | { | |
224 | sg->buf = kmalloc(PL011_DMA_BUFFER_SIZE, GFP_KERNEL); | |
225 | if (!sg->buf) | |
226 | return -ENOMEM; | |
227 | ||
228 | sg_init_one(&sg->sg, sg->buf, PL011_DMA_BUFFER_SIZE); | |
229 | ||
230 | if (dma_map_sg(chan->device->dev, &sg->sg, 1, dir) != 1) { | |
231 | kfree(sg->buf); | |
232 | return -EINVAL; | |
233 | } | |
234 | return 0; | |
235 | } | |
236 | ||
237 | static void pl011_sgbuf_free(struct dma_chan *chan, struct pl011_sgbuf *sg, | |
238 | enum dma_data_direction dir) | |
239 | { | |
240 | if (sg->buf) { | |
241 | dma_unmap_sg(chan->device->dev, &sg->sg, 1, dir); | |
242 | kfree(sg->buf); | |
243 | } | |
244 | } | |
245 | ||
68b65f73 RK |
246 | static void pl011_dma_probe_initcall(struct uart_amba_port *uap) |
247 | { | |
248 | /* DMA is the sole user of the platform data right now */ | |
249 | struct amba_pl011_data *plat = uap->port.dev->platform_data; | |
250 | struct dma_slave_config tx_conf = { | |
251 | .dst_addr = uap->port.mapbase + UART01x_DR, | |
252 | .dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE, | |
a485df4b | 253 | .direction = DMA_MEM_TO_DEV, |
68b65f73 | 254 | .dst_maxburst = uap->fifosize >> 1, |
258aea76 | 255 | .device_fc = false, |
68b65f73 RK |
256 | }; |
257 | struct dma_chan *chan; | |
258 | dma_cap_mask_t mask; | |
259 | ||
260 | /* We need platform data */ | |
261 | if (!plat || !plat->dma_filter) { | |
262 | dev_info(uap->port.dev, "no DMA platform data\n"); | |
263 | return; | |
264 | } | |
265 | ||
ead76f32 | 266 | /* Try to acquire a generic DMA engine slave TX channel */ |
68b65f73 RK |
267 | dma_cap_zero(mask); |
268 | dma_cap_set(DMA_SLAVE, mask); | |
269 | ||
270 | chan = dma_request_channel(mask, plat->dma_filter, plat->dma_tx_param); | |
271 | if (!chan) { | |
272 | dev_err(uap->port.dev, "no TX DMA channel!\n"); | |
273 | return; | |
274 | } | |
275 | ||
276 | dmaengine_slave_config(chan, &tx_conf); | |
277 | uap->dmatx.chan = chan; | |
278 | ||
279 | dev_info(uap->port.dev, "DMA channel TX %s\n", | |
280 | dma_chan_name(uap->dmatx.chan)); | |
ead76f32 LW |
281 | |
282 | /* Optionally make use of an RX channel as well */ | |
283 | if (plat->dma_rx_param) { | |
284 | struct dma_slave_config rx_conf = { | |
285 | .src_addr = uap->port.mapbase + UART01x_DR, | |
286 | .src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE, | |
a485df4b | 287 | .direction = DMA_DEV_TO_MEM, |
ead76f32 | 288 | .src_maxburst = uap->fifosize >> 1, |
258aea76 | 289 | .device_fc = false, |
ead76f32 LW |
290 | }; |
291 | ||
292 | chan = dma_request_channel(mask, plat->dma_filter, plat->dma_rx_param); | |
293 | if (!chan) { | |
294 | dev_err(uap->port.dev, "no RX DMA channel!\n"); | |
295 | return; | |
296 | } | |
297 | ||
298 | dmaengine_slave_config(chan, &rx_conf); | |
299 | uap->dmarx.chan = chan; | |
300 | ||
301 | dev_info(uap->port.dev, "DMA channel RX %s\n", | |
302 | dma_chan_name(uap->dmarx.chan)); | |
303 | } | |
68b65f73 RK |
304 | } |
305 | ||
306 | #ifndef MODULE | |
307 | /* | |
308 | * Stack up the UARTs and let the above initcall be done at device | |
309 | * initcall time, because the serial driver is called as an arch | |
310 | * initcall, and at this time the DMA subsystem is not yet registered. | |
311 | * At this point the driver will switch over to using DMA where desired. | |
312 | */ | |
313 | struct dma_uap { | |
314 | struct list_head node; | |
315 | struct uart_amba_port *uap; | |
c19f12b5 RK |
316 | }; |
317 | ||
68b65f73 RK |
318 | static LIST_HEAD(pl011_dma_uarts); |
319 | ||
320 | static int __init pl011_dma_initcall(void) | |
321 | { | |
322 | struct list_head *node, *tmp; | |
323 | ||
324 | list_for_each_safe(node, tmp, &pl011_dma_uarts) { | |
325 | struct dma_uap *dmau = list_entry(node, struct dma_uap, node); | |
326 | pl011_dma_probe_initcall(dmau->uap); | |
327 | list_del(node); | |
328 | kfree(dmau); | |
329 | } | |
330 | return 0; | |
331 | } | |
332 | ||
333 | device_initcall(pl011_dma_initcall); | |
334 | ||
335 | static void pl011_dma_probe(struct uart_amba_port *uap) | |
336 | { | |
337 | struct dma_uap *dmau = kzalloc(sizeof(struct dma_uap), GFP_KERNEL); | |
338 | if (dmau) { | |
339 | dmau->uap = uap; | |
340 | list_add_tail(&dmau->node, &pl011_dma_uarts); | |
341 | } | |
342 | } | |
343 | #else | |
344 | static void pl011_dma_probe(struct uart_amba_port *uap) | |
345 | { | |
346 | pl011_dma_probe_initcall(uap); | |
347 | } | |
348 | #endif | |
349 | ||
350 | static void pl011_dma_remove(struct uart_amba_port *uap) | |
351 | { | |
352 | /* TODO: remove the initcall if it has not yet executed */ | |
353 | if (uap->dmatx.chan) | |
354 | dma_release_channel(uap->dmatx.chan); | |
ead76f32 LW |
355 | if (uap->dmarx.chan) |
356 | dma_release_channel(uap->dmarx.chan); | |
68b65f73 RK |
357 | } |
358 | ||
68b65f73 RK |
359 | /* Forward declare this for the refill routine */ |
360 | static int pl011_dma_tx_refill(struct uart_amba_port *uap); | |
361 | ||
362 | /* | |
363 | * The current DMA TX buffer has been sent. | |
364 | * Try to queue up another DMA buffer. | |
365 | */ | |
366 | static void pl011_dma_tx_callback(void *data) | |
367 | { | |
368 | struct uart_amba_port *uap = data; | |
369 | struct pl011_dmatx_data *dmatx = &uap->dmatx; | |
370 | unsigned long flags; | |
371 | u16 dmacr; | |
372 | ||
373 | spin_lock_irqsave(&uap->port.lock, flags); | |
374 | if (uap->dmatx.queued) | |
375 | dma_unmap_sg(dmatx->chan->device->dev, &dmatx->sg, 1, | |
376 | DMA_TO_DEVICE); | |
377 | ||
378 | dmacr = uap->dmacr; | |
379 | uap->dmacr = dmacr & ~UART011_TXDMAE; | |
380 | writew(uap->dmacr, uap->port.membase + UART011_DMACR); | |
381 | ||
382 | /* | |
383 | * If TX DMA was disabled, it means that we've stopped the DMA for | |
384 | * some reason (eg, XOFF received, or we want to send an X-char.) | |
385 | * | |
386 | * Note: we need to be careful here of a potential race between DMA | |
387 | * and the rest of the driver - if the driver disables TX DMA while | |
388 | * a TX buffer completing, we must update the tx queued status to | |
389 | * get further refills (hence we check dmacr). | |
390 | */ | |
391 | if (!(dmacr & UART011_TXDMAE) || uart_tx_stopped(&uap->port) || | |
392 | uart_circ_empty(&uap->port.state->xmit)) { | |
393 | uap->dmatx.queued = false; | |
394 | spin_unlock_irqrestore(&uap->port.lock, flags); | |
395 | return; | |
396 | } | |
397 | ||
398 | if (pl011_dma_tx_refill(uap) <= 0) { | |
399 | /* | |
400 | * We didn't queue a DMA buffer for some reason, but we | |
401 | * have data pending to be sent. Re-enable the TX IRQ. | |
402 | */ | |
403 | uap->im |= UART011_TXIM; | |
404 | writew(uap->im, uap->port.membase + UART011_IMSC); | |
405 | } | |
406 | spin_unlock_irqrestore(&uap->port.lock, flags); | |
407 | } | |
408 | ||
409 | /* | |
410 | * Try to refill the TX DMA buffer. | |
411 | * Locking: called with port lock held and IRQs disabled. | |
412 | * Returns: | |
413 | * 1 if we queued up a TX DMA buffer. | |
414 | * 0 if we didn't want to handle this by DMA | |
415 | * <0 on error | |
416 | */ | |
417 | static int pl011_dma_tx_refill(struct uart_amba_port *uap) | |
418 | { | |
419 | struct pl011_dmatx_data *dmatx = &uap->dmatx; | |
420 | struct dma_chan *chan = dmatx->chan; | |
421 | struct dma_device *dma_dev = chan->device; | |
422 | struct dma_async_tx_descriptor *desc; | |
423 | struct circ_buf *xmit = &uap->port.state->xmit; | |
424 | unsigned int count; | |
425 | ||
426 | /* | |
427 | * Try to avoid the overhead involved in using DMA if the | |
428 | * transaction fits in the first half of the FIFO, by using | |
429 | * the standard interrupt handling. This ensures that we | |
430 | * issue a uart_write_wakeup() at the appropriate time. | |
431 | */ | |
432 | count = uart_circ_chars_pending(xmit); | |
433 | if (count < (uap->fifosize >> 1)) { | |
434 | uap->dmatx.queued = false; | |
435 | return 0; | |
436 | } | |
437 | ||
438 | /* | |
439 | * Bodge: don't send the last character by DMA, as this | |
440 | * will prevent XON from notifying us to restart DMA. | |
441 | */ | |
442 | count -= 1; | |
443 | ||
444 | /* Else proceed to copy the TX chars to the DMA buffer and fire DMA */ | |
445 | if (count > PL011_DMA_BUFFER_SIZE) | |
446 | count = PL011_DMA_BUFFER_SIZE; | |
447 | ||
448 | if (xmit->tail < xmit->head) | |
449 | memcpy(&dmatx->buf[0], &xmit->buf[xmit->tail], count); | |
450 | else { | |
451 | size_t first = UART_XMIT_SIZE - xmit->tail; | |
452 | size_t second = xmit->head; | |
453 | ||
454 | memcpy(&dmatx->buf[0], &xmit->buf[xmit->tail], first); | |
455 | if (second) | |
456 | memcpy(&dmatx->buf[first], &xmit->buf[0], second); | |
457 | } | |
458 | ||
459 | dmatx->sg.length = count; | |
460 | ||
461 | if (dma_map_sg(dma_dev->dev, &dmatx->sg, 1, DMA_TO_DEVICE) != 1) { | |
462 | uap->dmatx.queued = false; | |
463 | dev_dbg(uap->port.dev, "unable to map TX DMA\n"); | |
464 | return -EBUSY; | |
465 | } | |
466 | ||
16052827 | 467 | desc = dmaengine_prep_slave_sg(chan, &dmatx->sg, 1, DMA_MEM_TO_DEV, |
68b65f73 RK |
468 | DMA_PREP_INTERRUPT | DMA_CTRL_ACK); |
469 | if (!desc) { | |
470 | dma_unmap_sg(dma_dev->dev, &dmatx->sg, 1, DMA_TO_DEVICE); | |
471 | uap->dmatx.queued = false; | |
472 | /* | |
473 | * If DMA cannot be used right now, we complete this | |
474 | * transaction via IRQ and let the TTY layer retry. | |
475 | */ | |
476 | dev_dbg(uap->port.dev, "TX DMA busy\n"); | |
477 | return -EBUSY; | |
478 | } | |
479 | ||
480 | /* Some data to go along to the callback */ | |
481 | desc->callback = pl011_dma_tx_callback; | |
482 | desc->callback_param = uap; | |
483 | ||
484 | /* All errors should happen at prepare time */ | |
485 | dmaengine_submit(desc); | |
486 | ||
487 | /* Fire the DMA transaction */ | |
488 | dma_dev->device_issue_pending(chan); | |
489 | ||
490 | uap->dmacr |= UART011_TXDMAE; | |
491 | writew(uap->dmacr, uap->port.membase + UART011_DMACR); | |
492 | uap->dmatx.queued = true; | |
493 | ||
494 | /* | |
495 | * Now we know that DMA will fire, so advance the ring buffer | |
496 | * with the stuff we just dispatched. | |
497 | */ | |
498 | xmit->tail = (xmit->tail + count) & (UART_XMIT_SIZE - 1); | |
499 | uap->port.icount.tx += count; | |
500 | ||
501 | if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) | |
502 | uart_write_wakeup(&uap->port); | |
503 | ||
504 | return 1; | |
505 | } | |
506 | ||
507 | /* | |
508 | * We received a transmit interrupt without a pending X-char but with | |
509 | * pending characters. | |
510 | * Locking: called with port lock held and IRQs disabled. | |
511 | * Returns: | |
512 | * false if we want to use PIO to transmit | |
513 | * true if we queued a DMA buffer | |
514 | */ | |
515 | static bool pl011_dma_tx_irq(struct uart_amba_port *uap) | |
516 | { | |
ead76f32 | 517 | if (!uap->using_tx_dma) |
68b65f73 RK |
518 | return false; |
519 | ||
520 | /* | |
521 | * If we already have a TX buffer queued, but received a | |
522 | * TX interrupt, it will be because we've just sent an X-char. | |
523 | * Ensure the TX DMA is enabled and the TX IRQ is disabled. | |
524 | */ | |
525 | if (uap->dmatx.queued) { | |
526 | uap->dmacr |= UART011_TXDMAE; | |
527 | writew(uap->dmacr, uap->port.membase + UART011_DMACR); | |
528 | uap->im &= ~UART011_TXIM; | |
529 | writew(uap->im, uap->port.membase + UART011_IMSC); | |
530 | return true; | |
531 | } | |
532 | ||
533 | /* | |
534 | * We don't have a TX buffer queued, so try to queue one. | |
25985edc | 535 | * If we successfully queued a buffer, mask the TX IRQ. |
68b65f73 RK |
536 | */ |
537 | if (pl011_dma_tx_refill(uap) > 0) { | |
538 | uap->im &= ~UART011_TXIM; | |
539 | writew(uap->im, uap->port.membase + UART011_IMSC); | |
540 | return true; | |
541 | } | |
542 | return false; | |
543 | } | |
544 | ||
545 | /* | |
546 | * Stop the DMA transmit (eg, due to received XOFF). | |
547 | * Locking: called with port lock held and IRQs disabled. | |
548 | */ | |
549 | static inline void pl011_dma_tx_stop(struct uart_amba_port *uap) | |
550 | { | |
551 | if (uap->dmatx.queued) { | |
552 | uap->dmacr &= ~UART011_TXDMAE; | |
553 | writew(uap->dmacr, uap->port.membase + UART011_DMACR); | |
554 | } | |
555 | } | |
556 | ||
557 | /* | |
558 | * Try to start a DMA transmit, or in the case of an XON/OFF | |
559 | * character queued for send, try to get that character out ASAP. | |
560 | * Locking: called with port lock held and IRQs disabled. | |
561 | * Returns: | |
562 | * false if we want the TX IRQ to be enabled | |
563 | * true if we have a buffer queued | |
564 | */ | |
565 | static inline bool pl011_dma_tx_start(struct uart_amba_port *uap) | |
566 | { | |
567 | u16 dmacr; | |
568 | ||
ead76f32 | 569 | if (!uap->using_tx_dma) |
68b65f73 RK |
570 | return false; |
571 | ||
572 | if (!uap->port.x_char) { | |
573 | /* no X-char, try to push chars out in DMA mode */ | |
574 | bool ret = true; | |
575 | ||
576 | if (!uap->dmatx.queued) { | |
577 | if (pl011_dma_tx_refill(uap) > 0) { | |
578 | uap->im &= ~UART011_TXIM; | |
579 | ret = true; | |
580 | } else { | |
581 | uap->im |= UART011_TXIM; | |
582 | ret = false; | |
583 | } | |
584 | writew(uap->im, uap->port.membase + UART011_IMSC); | |
585 | } else if (!(uap->dmacr & UART011_TXDMAE)) { | |
586 | uap->dmacr |= UART011_TXDMAE; | |
587 | writew(uap->dmacr, | |
588 | uap->port.membase + UART011_DMACR); | |
589 | } | |
590 | return ret; | |
591 | } | |
592 | ||
593 | /* | |
594 | * We have an X-char to send. Disable DMA to prevent it loading | |
595 | * the TX fifo, and then see if we can stuff it into the FIFO. | |
596 | */ | |
597 | dmacr = uap->dmacr; | |
598 | uap->dmacr &= ~UART011_TXDMAE; | |
599 | writew(uap->dmacr, uap->port.membase + UART011_DMACR); | |
600 | ||
601 | if (readw(uap->port.membase + UART01x_FR) & UART01x_FR_TXFF) { | |
602 | /* | |
603 | * No space in the FIFO, so enable the transmit interrupt | |
604 | * so we know when there is space. Note that once we've | |
605 | * loaded the character, we should just re-enable DMA. | |
606 | */ | |
607 | return false; | |
608 | } | |
609 | ||
610 | writew(uap->port.x_char, uap->port.membase + UART01x_DR); | |
611 | uap->port.icount.tx++; | |
612 | uap->port.x_char = 0; | |
613 | ||
614 | /* Success - restore the DMA state */ | |
615 | uap->dmacr = dmacr; | |
616 | writew(dmacr, uap->port.membase + UART011_DMACR); | |
617 | ||
618 | return true; | |
619 | } | |
620 | ||
621 | /* | |
622 | * Flush the transmit buffer. | |
623 | * Locking: called with port lock held and IRQs disabled. | |
624 | */ | |
625 | static void pl011_dma_flush_buffer(struct uart_port *port) | |
626 | { | |
627 | struct uart_amba_port *uap = (struct uart_amba_port *)port; | |
628 | ||
ead76f32 | 629 | if (!uap->using_tx_dma) |
68b65f73 RK |
630 | return; |
631 | ||
632 | /* Avoid deadlock with the DMA engine callback */ | |
633 | spin_unlock(&uap->port.lock); | |
634 | dmaengine_terminate_all(uap->dmatx.chan); | |
635 | spin_lock(&uap->port.lock); | |
636 | if (uap->dmatx.queued) { | |
637 | dma_unmap_sg(uap->dmatx.chan->device->dev, &uap->dmatx.sg, 1, | |
638 | DMA_TO_DEVICE); | |
639 | uap->dmatx.queued = false; | |
640 | uap->dmacr &= ~UART011_TXDMAE; | |
641 | writew(uap->dmacr, uap->port.membase + UART011_DMACR); | |
642 | } | |
643 | } | |
644 | ||
ead76f32 LW |
645 | static void pl011_dma_rx_callback(void *data); |
646 | ||
647 | static int pl011_dma_rx_trigger_dma(struct uart_amba_port *uap) | |
648 | { | |
649 | struct dma_chan *rxchan = uap->dmarx.chan; | |
ead76f32 LW |
650 | struct pl011_dmarx_data *dmarx = &uap->dmarx; |
651 | struct dma_async_tx_descriptor *desc; | |
652 | struct pl011_sgbuf *sgbuf; | |
653 | ||
654 | if (!rxchan) | |
655 | return -EIO; | |
656 | ||
657 | /* Start the RX DMA job */ | |
658 | sgbuf = uap->dmarx.use_buf_b ? | |
659 | &uap->dmarx.sgbuf_b : &uap->dmarx.sgbuf_a; | |
16052827 | 660 | desc = dmaengine_prep_slave_sg(rxchan, &sgbuf->sg, 1, |
a485df4b | 661 | DMA_DEV_TO_MEM, |
ead76f32 LW |
662 | DMA_PREP_INTERRUPT | DMA_CTRL_ACK); |
663 | /* | |
664 | * If the DMA engine is busy and cannot prepare a | |
665 | * channel, no big deal, the driver will fall back | |
666 | * to interrupt mode as a result of this error code. | |
667 | */ | |
668 | if (!desc) { | |
669 | uap->dmarx.running = false; | |
670 | dmaengine_terminate_all(rxchan); | |
671 | return -EBUSY; | |
672 | } | |
673 | ||
674 | /* Some data to go along to the callback */ | |
675 | desc->callback = pl011_dma_rx_callback; | |
676 | desc->callback_param = uap; | |
677 | dmarx->cookie = dmaengine_submit(desc); | |
678 | dma_async_issue_pending(rxchan); | |
679 | ||
680 | uap->dmacr |= UART011_RXDMAE; | |
681 | writew(uap->dmacr, uap->port.membase + UART011_DMACR); | |
682 | uap->dmarx.running = true; | |
683 | ||
684 | uap->im &= ~UART011_RXIM; | |
685 | writew(uap->im, uap->port.membase + UART011_IMSC); | |
686 | ||
687 | return 0; | |
688 | } | |
689 | ||
690 | /* | |
691 | * This is called when either the DMA job is complete, or | |
692 | * the FIFO timeout interrupt occurred. This must be called | |
693 | * with the port spinlock uap->port.lock held. | |
694 | */ | |
695 | static void pl011_dma_rx_chars(struct uart_amba_port *uap, | |
696 | u32 pending, bool use_buf_b, | |
697 | bool readfifo) | |
698 | { | |
699 | struct tty_struct *tty = uap->port.state->port.tty; | |
700 | struct pl011_sgbuf *sgbuf = use_buf_b ? | |
701 | &uap->dmarx.sgbuf_b : &uap->dmarx.sgbuf_a; | |
702 | struct device *dev = uap->dmarx.chan->device->dev; | |
ead76f32 LW |
703 | int dma_count = 0; |
704 | u32 fifotaken = 0; /* only used for vdbg() */ | |
705 | ||
706 | /* Pick everything from the DMA first */ | |
707 | if (pending) { | |
708 | /* Sync in buffer */ | |
709 | dma_sync_sg_for_cpu(dev, &sgbuf->sg, 1, DMA_FROM_DEVICE); | |
710 | ||
711 | /* | |
712 | * First take all chars in the DMA pipe, then look in the FIFO. | |
713 | * Note that tty_insert_flip_buf() tries to take as many chars | |
714 | * as it can. | |
715 | */ | |
716 | dma_count = tty_insert_flip_string(uap->port.state->port.tty, | |
717 | sgbuf->buf, pending); | |
718 | ||
719 | /* Return buffer to device */ | |
720 | dma_sync_sg_for_device(dev, &sgbuf->sg, 1, DMA_FROM_DEVICE); | |
721 | ||
722 | uap->port.icount.rx += dma_count; | |
723 | if (dma_count < pending) | |
724 | dev_warn(uap->port.dev, | |
725 | "couldn't insert all characters (TTY is full?)\n"); | |
726 | } | |
727 | ||
728 | /* | |
729 | * Only continue with trying to read the FIFO if all DMA chars have | |
730 | * been taken first. | |
731 | */ | |
732 | if (dma_count == pending && readfifo) { | |
733 | /* Clear any error flags */ | |
734 | writew(UART011_OEIS | UART011_BEIS | UART011_PEIS | UART011_FEIS, | |
735 | uap->port.membase + UART011_ICR); | |
736 | ||
737 | /* | |
738 | * If we read all the DMA'd characters, and we had an | |
29772c4e LW |
739 | * incomplete buffer, that could be due to an rx error, or |
740 | * maybe we just timed out. Read any pending chars and check | |
741 | * the error status. | |
742 | * | |
743 | * Error conditions will only occur in the FIFO, these will | |
744 | * trigger an immediate interrupt and stop the DMA job, so we | |
745 | * will always find the error in the FIFO, never in the DMA | |
746 | * buffer. | |
ead76f32 | 747 | */ |
29772c4e | 748 | fifotaken = pl011_fifo_to_tty(uap); |
ead76f32 LW |
749 | } |
750 | ||
751 | spin_unlock(&uap->port.lock); | |
752 | dev_vdbg(uap->port.dev, | |
753 | "Took %d chars from DMA buffer and %d chars from the FIFO\n", | |
754 | dma_count, fifotaken); | |
755 | tty_flip_buffer_push(tty); | |
756 | spin_lock(&uap->port.lock); | |
757 | } | |
758 | ||
759 | static void pl011_dma_rx_irq(struct uart_amba_port *uap) | |
760 | { | |
761 | struct pl011_dmarx_data *dmarx = &uap->dmarx; | |
762 | struct dma_chan *rxchan = dmarx->chan; | |
763 | struct pl011_sgbuf *sgbuf = dmarx->use_buf_b ? | |
764 | &dmarx->sgbuf_b : &dmarx->sgbuf_a; | |
765 | size_t pending; | |
766 | struct dma_tx_state state; | |
767 | enum dma_status dmastat; | |
768 | ||
769 | /* | |
770 | * Pause the transfer so we can trust the current counter, | |
771 | * do this before we pause the PL011 block, else we may | |
772 | * overflow the FIFO. | |
773 | */ | |
774 | if (dmaengine_pause(rxchan)) | |
775 | dev_err(uap->port.dev, "unable to pause DMA transfer\n"); | |
776 | dmastat = rxchan->device->device_tx_status(rxchan, | |
777 | dmarx->cookie, &state); | |
778 | if (dmastat != DMA_PAUSED) | |
779 | dev_err(uap->port.dev, "unable to pause DMA transfer\n"); | |
780 | ||
781 | /* Disable RX DMA - incoming data will wait in the FIFO */ | |
782 | uap->dmacr &= ~UART011_RXDMAE; | |
783 | writew(uap->dmacr, uap->port.membase + UART011_DMACR); | |
784 | uap->dmarx.running = false; | |
785 | ||
786 | pending = sgbuf->sg.length - state.residue; | |
787 | BUG_ON(pending > PL011_DMA_BUFFER_SIZE); | |
788 | /* Then we terminate the transfer - we now know our residue */ | |
789 | dmaengine_terminate_all(rxchan); | |
790 | ||
791 | /* | |
792 | * This will take the chars we have so far and insert | |
793 | * into the framework. | |
794 | */ | |
795 | pl011_dma_rx_chars(uap, pending, dmarx->use_buf_b, true); | |
796 | ||
797 | /* Switch buffer & re-trigger DMA job */ | |
798 | dmarx->use_buf_b = !dmarx->use_buf_b; | |
799 | if (pl011_dma_rx_trigger_dma(uap)) { | |
800 | dev_dbg(uap->port.dev, "could not retrigger RX DMA job " | |
801 | "fall back to interrupt mode\n"); | |
802 | uap->im |= UART011_RXIM; | |
803 | writew(uap->im, uap->port.membase + UART011_IMSC); | |
804 | } | |
805 | } | |
806 | ||
807 | static void pl011_dma_rx_callback(void *data) | |
808 | { | |
809 | struct uart_amba_port *uap = data; | |
810 | struct pl011_dmarx_data *dmarx = &uap->dmarx; | |
6dc01aa6 | 811 | struct dma_chan *rxchan = dmarx->chan; |
ead76f32 | 812 | bool lastbuf = dmarx->use_buf_b; |
6dc01aa6 CM |
813 | struct pl011_sgbuf *sgbuf = dmarx->use_buf_b ? |
814 | &dmarx->sgbuf_b : &dmarx->sgbuf_a; | |
815 | size_t pending; | |
816 | struct dma_tx_state state; | |
ead76f32 LW |
817 | int ret; |
818 | ||
819 | /* | |
820 | * This completion interrupt occurs typically when the | |
821 | * RX buffer is totally stuffed but no timeout has yet | |
822 | * occurred. When that happens, we just want the RX | |
823 | * routine to flush out the secondary DMA buffer while | |
824 | * we immediately trigger the next DMA job. | |
825 | */ | |
826 | spin_lock_irq(&uap->port.lock); | |
6dc01aa6 CM |
827 | /* |
828 | * Rx data can be taken by the UART interrupts during | |
829 | * the DMA irq handler. So we check the residue here. | |
830 | */ | |
831 | rxchan->device->device_tx_status(rxchan, dmarx->cookie, &state); | |
832 | pending = sgbuf->sg.length - state.residue; | |
833 | BUG_ON(pending > PL011_DMA_BUFFER_SIZE); | |
834 | /* Then we terminate the transfer - we now know our residue */ | |
835 | dmaengine_terminate_all(rxchan); | |
836 | ||
ead76f32 LW |
837 | uap->dmarx.running = false; |
838 | dmarx->use_buf_b = !lastbuf; | |
839 | ret = pl011_dma_rx_trigger_dma(uap); | |
840 | ||
6dc01aa6 | 841 | pl011_dma_rx_chars(uap, pending, lastbuf, false); |
ead76f32 LW |
842 | spin_unlock_irq(&uap->port.lock); |
843 | /* | |
844 | * Do this check after we picked the DMA chars so we don't | |
845 | * get some IRQ immediately from RX. | |
846 | */ | |
847 | if (ret) { | |
848 | dev_dbg(uap->port.dev, "could not retrigger RX DMA job " | |
849 | "fall back to interrupt mode\n"); | |
850 | uap->im |= UART011_RXIM; | |
851 | writew(uap->im, uap->port.membase + UART011_IMSC); | |
852 | } | |
853 | } | |
854 | ||
855 | /* | |
856 | * Stop accepting received characters, when we're shutting down or | |
857 | * suspending this port. | |
858 | * Locking: called with port lock held and IRQs disabled. | |
859 | */ | |
860 | static inline void pl011_dma_rx_stop(struct uart_amba_port *uap) | |
861 | { | |
862 | /* FIXME. Just disable the DMA enable */ | |
863 | uap->dmacr &= ~UART011_RXDMAE; | |
864 | writew(uap->dmacr, uap->port.membase + UART011_DMACR); | |
865 | } | |
68b65f73 RK |
866 | |
867 | static void pl011_dma_startup(struct uart_amba_port *uap) | |
868 | { | |
ead76f32 LW |
869 | int ret; |
870 | ||
68b65f73 RK |
871 | if (!uap->dmatx.chan) |
872 | return; | |
873 | ||
874 | uap->dmatx.buf = kmalloc(PL011_DMA_BUFFER_SIZE, GFP_KERNEL); | |
875 | if (!uap->dmatx.buf) { | |
876 | dev_err(uap->port.dev, "no memory for DMA TX buffer\n"); | |
877 | uap->port.fifosize = uap->fifosize; | |
878 | return; | |
879 | } | |
880 | ||
881 | sg_init_one(&uap->dmatx.sg, uap->dmatx.buf, PL011_DMA_BUFFER_SIZE); | |
882 | ||
883 | /* The DMA buffer is now the FIFO the TTY subsystem can use */ | |
884 | uap->port.fifosize = PL011_DMA_BUFFER_SIZE; | |
ead76f32 LW |
885 | uap->using_tx_dma = true; |
886 | ||
887 | if (!uap->dmarx.chan) | |
888 | goto skip_rx; | |
889 | ||
890 | /* Allocate and map DMA RX buffers */ | |
891 | ret = pl011_sgbuf_init(uap->dmarx.chan, &uap->dmarx.sgbuf_a, | |
892 | DMA_FROM_DEVICE); | |
893 | if (ret) { | |
894 | dev_err(uap->port.dev, "failed to init DMA %s: %d\n", | |
895 | "RX buffer A", ret); | |
896 | goto skip_rx; | |
897 | } | |
68b65f73 | 898 | |
ead76f32 LW |
899 | ret = pl011_sgbuf_init(uap->dmarx.chan, &uap->dmarx.sgbuf_b, |
900 | DMA_FROM_DEVICE); | |
901 | if (ret) { | |
902 | dev_err(uap->port.dev, "failed to init DMA %s: %d\n", | |
903 | "RX buffer B", ret); | |
904 | pl011_sgbuf_free(uap->dmarx.chan, &uap->dmarx.sgbuf_a, | |
905 | DMA_FROM_DEVICE); | |
906 | goto skip_rx; | |
907 | } | |
908 | ||
909 | uap->using_rx_dma = true; | |
68b65f73 | 910 | |
ead76f32 | 911 | skip_rx: |
68b65f73 RK |
912 | /* Turn on DMA error (RX/TX will be enabled on demand) */ |
913 | uap->dmacr |= UART011_DMAONERR; | |
914 | writew(uap->dmacr, uap->port.membase + UART011_DMACR); | |
38d62436 RK |
915 | |
916 | /* | |
917 | * ST Micro variants has some specific dma burst threshold | |
918 | * compensation. Set this to 16 bytes, so burst will only | |
919 | * be issued above/below 16 bytes. | |
920 | */ | |
921 | if (uap->vendor->dma_threshold) | |
922 | writew(ST_UART011_DMAWM_RX_16 | ST_UART011_DMAWM_TX_16, | |
923 | uap->port.membase + ST_UART011_DMAWM); | |
ead76f32 LW |
924 | |
925 | if (uap->using_rx_dma) { | |
926 | if (pl011_dma_rx_trigger_dma(uap)) | |
927 | dev_dbg(uap->port.dev, "could not trigger initial " | |
928 | "RX DMA job, fall back to interrupt mode\n"); | |
929 | } | |
68b65f73 RK |
930 | } |
931 | ||
932 | static void pl011_dma_shutdown(struct uart_amba_port *uap) | |
933 | { | |
ead76f32 | 934 | if (!(uap->using_tx_dma || uap->using_rx_dma)) |
68b65f73 RK |
935 | return; |
936 | ||
937 | /* Disable RX and TX DMA */ | |
938 | while (readw(uap->port.membase + UART01x_FR) & UART01x_FR_BUSY) | |
939 | barrier(); | |
940 | ||
941 | spin_lock_irq(&uap->port.lock); | |
942 | uap->dmacr &= ~(UART011_DMAONERR | UART011_RXDMAE | UART011_TXDMAE); | |
943 | writew(uap->dmacr, uap->port.membase + UART011_DMACR); | |
944 | spin_unlock_irq(&uap->port.lock); | |
945 | ||
ead76f32 LW |
946 | if (uap->using_tx_dma) { |
947 | /* In theory, this should already be done by pl011_dma_flush_buffer */ | |
948 | dmaengine_terminate_all(uap->dmatx.chan); | |
949 | if (uap->dmatx.queued) { | |
950 | dma_unmap_sg(uap->dmatx.chan->device->dev, &uap->dmatx.sg, 1, | |
951 | DMA_TO_DEVICE); | |
952 | uap->dmatx.queued = false; | |
953 | } | |
954 | ||
955 | kfree(uap->dmatx.buf); | |
956 | uap->using_tx_dma = false; | |
68b65f73 RK |
957 | } |
958 | ||
ead76f32 LW |
959 | if (uap->using_rx_dma) { |
960 | dmaengine_terminate_all(uap->dmarx.chan); | |
961 | /* Clean up the RX DMA */ | |
962 | pl011_sgbuf_free(uap->dmarx.chan, &uap->dmarx.sgbuf_a, DMA_FROM_DEVICE); | |
963 | pl011_sgbuf_free(uap->dmarx.chan, &uap->dmarx.sgbuf_b, DMA_FROM_DEVICE); | |
964 | uap->using_rx_dma = false; | |
965 | } | |
966 | } | |
68b65f73 | 967 | |
ead76f32 LW |
968 | static inline bool pl011_dma_rx_available(struct uart_amba_port *uap) |
969 | { | |
970 | return uap->using_rx_dma; | |
68b65f73 RK |
971 | } |
972 | ||
ead76f32 LW |
973 | static inline bool pl011_dma_rx_running(struct uart_amba_port *uap) |
974 | { | |
975 | return uap->using_rx_dma && uap->dmarx.running; | |
976 | } | |
977 | ||
978 | ||
68b65f73 RK |
979 | #else |
980 | /* Blank functions if the DMA engine is not available */ | |
981 | static inline void pl011_dma_probe(struct uart_amba_port *uap) | |
982 | { | |
983 | } | |
984 | ||
985 | static inline void pl011_dma_remove(struct uart_amba_port *uap) | |
986 | { | |
987 | } | |
988 | ||
989 | static inline void pl011_dma_startup(struct uart_amba_port *uap) | |
990 | { | |
991 | } | |
992 | ||
993 | static inline void pl011_dma_shutdown(struct uart_amba_port *uap) | |
994 | { | |
995 | } | |
996 | ||
997 | static inline bool pl011_dma_tx_irq(struct uart_amba_port *uap) | |
998 | { | |
999 | return false; | |
1000 | } | |
1001 | ||
1002 | static inline void pl011_dma_tx_stop(struct uart_amba_port *uap) | |
1003 | { | |
1004 | } | |
1005 | ||
1006 | static inline bool pl011_dma_tx_start(struct uart_amba_port *uap) | |
1007 | { | |
1008 | return false; | |
1009 | } | |
1010 | ||
ead76f32 LW |
1011 | static inline void pl011_dma_rx_irq(struct uart_amba_port *uap) |
1012 | { | |
1013 | } | |
1014 | ||
1015 | static inline void pl011_dma_rx_stop(struct uart_amba_port *uap) | |
1016 | { | |
1017 | } | |
1018 | ||
1019 | static inline int pl011_dma_rx_trigger_dma(struct uart_amba_port *uap) | |
1020 | { | |
1021 | return -EIO; | |
1022 | } | |
1023 | ||
1024 | static inline bool pl011_dma_rx_available(struct uart_amba_port *uap) | |
1025 | { | |
1026 | return false; | |
1027 | } | |
1028 | ||
1029 | static inline bool pl011_dma_rx_running(struct uart_amba_port *uap) | |
1030 | { | |
1031 | return false; | |
1032 | } | |
1033 | ||
68b65f73 RK |
1034 | #define pl011_dma_flush_buffer NULL |
1035 | #endif | |
1036 | ||
b129a8cc | 1037 | static void pl011_stop_tx(struct uart_port *port) |
1da177e4 LT |
1038 | { |
1039 | struct uart_amba_port *uap = (struct uart_amba_port *)port; | |
1040 | ||
1041 | uap->im &= ~UART011_TXIM; | |
1042 | writew(uap->im, uap->port.membase + UART011_IMSC); | |
68b65f73 | 1043 | pl011_dma_tx_stop(uap); |
1da177e4 LT |
1044 | } |
1045 | ||
b129a8cc | 1046 | static void pl011_start_tx(struct uart_port *port) |
1da177e4 LT |
1047 | { |
1048 | struct uart_amba_port *uap = (struct uart_amba_port *)port; | |
1049 | ||
68b65f73 RK |
1050 | if (!pl011_dma_tx_start(uap)) { |
1051 | uap->im |= UART011_TXIM; | |
1052 | writew(uap->im, uap->port.membase + UART011_IMSC); | |
1053 | } | |
1da177e4 LT |
1054 | } |
1055 | ||
1056 | static void pl011_stop_rx(struct uart_port *port) | |
1057 | { | |
1058 | struct uart_amba_port *uap = (struct uart_amba_port *)port; | |
1059 | ||
1060 | uap->im &= ~(UART011_RXIM|UART011_RTIM|UART011_FEIM| | |
1061 | UART011_PEIM|UART011_BEIM|UART011_OEIM); | |
1062 | writew(uap->im, uap->port.membase + UART011_IMSC); | |
ead76f32 LW |
1063 | |
1064 | pl011_dma_rx_stop(uap); | |
1da177e4 LT |
1065 | } |
1066 | ||
1067 | static void pl011_enable_ms(struct uart_port *port) | |
1068 | { | |
1069 | struct uart_amba_port *uap = (struct uart_amba_port *)port; | |
1070 | ||
1071 | uap->im |= UART011_RIMIM|UART011_CTSMIM|UART011_DCDMIM|UART011_DSRMIM; | |
1072 | writew(uap->im, uap->port.membase + UART011_IMSC); | |
1073 | } | |
1074 | ||
7d12e780 | 1075 | static void pl011_rx_chars(struct uart_amba_port *uap) |
1da177e4 | 1076 | { |
ebd2c8f6 | 1077 | struct tty_struct *tty = uap->port.state->port.tty; |
1da177e4 | 1078 | |
29772c4e | 1079 | pl011_fifo_to_tty(uap); |
1da177e4 | 1080 | |
2389b272 | 1081 | spin_unlock(&uap->port.lock); |
1da177e4 | 1082 | tty_flip_buffer_push(tty); |
ead76f32 LW |
1083 | /* |
1084 | * If we were temporarily out of DMA mode for a while, | |
1085 | * attempt to switch back to DMA mode again. | |
1086 | */ | |
1087 | if (pl011_dma_rx_available(uap)) { | |
1088 | if (pl011_dma_rx_trigger_dma(uap)) { | |
1089 | dev_dbg(uap->port.dev, "could not trigger RX DMA job " | |
1090 | "fall back to interrupt mode again\n"); | |
1091 | uap->im |= UART011_RXIM; | |
1092 | } else | |
1093 | uap->im &= ~UART011_RXIM; | |
1094 | writew(uap->im, uap->port.membase + UART011_IMSC); | |
1095 | } | |
2389b272 | 1096 | spin_lock(&uap->port.lock); |
1da177e4 LT |
1097 | } |
1098 | ||
1099 | static void pl011_tx_chars(struct uart_amba_port *uap) | |
1100 | { | |
ebd2c8f6 | 1101 | struct circ_buf *xmit = &uap->port.state->xmit; |
1da177e4 LT |
1102 | int count; |
1103 | ||
1104 | if (uap->port.x_char) { | |
1105 | writew(uap->port.x_char, uap->port.membase + UART01x_DR); | |
1106 | uap->port.icount.tx++; | |
1107 | uap->port.x_char = 0; | |
1108 | return; | |
1109 | } | |
1110 | if (uart_circ_empty(xmit) || uart_tx_stopped(&uap->port)) { | |
b129a8cc | 1111 | pl011_stop_tx(&uap->port); |
1da177e4 LT |
1112 | return; |
1113 | } | |
1114 | ||
68b65f73 RK |
1115 | /* If we are using DMA mode, try to send some characters. */ |
1116 | if (pl011_dma_tx_irq(uap)) | |
1117 | return; | |
1118 | ||
ffca2b11 | 1119 | count = uap->fifosize >> 1; |
1da177e4 LT |
1120 | do { |
1121 | writew(xmit->buf[xmit->tail], uap->port.membase + UART01x_DR); | |
1122 | xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); | |
1123 | uap->port.icount.tx++; | |
1124 | if (uart_circ_empty(xmit)) | |
1125 | break; | |
1126 | } while (--count > 0); | |
1127 | ||
1128 | if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) | |
1129 | uart_write_wakeup(&uap->port); | |
1130 | ||
1131 | if (uart_circ_empty(xmit)) | |
b129a8cc | 1132 | pl011_stop_tx(&uap->port); |
1da177e4 LT |
1133 | } |
1134 | ||
1135 | static void pl011_modem_status(struct uart_amba_port *uap) | |
1136 | { | |
1137 | unsigned int status, delta; | |
1138 | ||
1139 | status = readw(uap->port.membase + UART01x_FR) & UART01x_FR_MODEM_ANY; | |
1140 | ||
1141 | delta = status ^ uap->old_status; | |
1142 | uap->old_status = status; | |
1143 | ||
1144 | if (!delta) | |
1145 | return; | |
1146 | ||
1147 | if (delta & UART01x_FR_DCD) | |
1148 | uart_handle_dcd_change(&uap->port, status & UART01x_FR_DCD); | |
1149 | ||
1150 | if (delta & UART01x_FR_DSR) | |
1151 | uap->port.icount.dsr++; | |
1152 | ||
1153 | if (delta & UART01x_FR_CTS) | |
1154 | uart_handle_cts_change(&uap->port, status & UART01x_FR_CTS); | |
1155 | ||
bdc04e31 | 1156 | wake_up_interruptible(&uap->port.state->port.delta_msr_wait); |
1da177e4 LT |
1157 | } |
1158 | ||
7d12e780 | 1159 | static irqreturn_t pl011_int(int irq, void *dev_id) |
1da177e4 LT |
1160 | { |
1161 | struct uart_amba_port *uap = dev_id; | |
963cc981 | 1162 | unsigned long flags; |
1da177e4 LT |
1163 | unsigned int status, pass_counter = AMBA_ISR_PASS_LIMIT; |
1164 | int handled = 0; | |
4fd0690b | 1165 | unsigned int dummy_read; |
1da177e4 | 1166 | |
963cc981 | 1167 | spin_lock_irqsave(&uap->port.lock, flags); |
1da177e4 LT |
1168 | |
1169 | status = readw(uap->port.membase + UART011_MIS); | |
1170 | if (status) { | |
1171 | do { | |
4fd0690b R |
1172 | if (uap->vendor->cts_event_workaround) { |
1173 | /* workaround to make sure that all bits are unlocked.. */ | |
1174 | writew(0x00, uap->port.membase + UART011_ICR); | |
1175 | ||
1176 | /* | |
1177 | * WA: introduce 26ns(1 uart clk) delay before W1C; | |
1178 | * single apb access will incur 2 pclk(133.12Mhz) delay, | |
1179 | * so add 2 dummy reads | |
1180 | */ | |
1181 | dummy_read = readw(uap->port.membase + UART011_ICR); | |
1182 | dummy_read = readw(uap->port.membase + UART011_ICR); | |
1183 | } | |
1184 | ||
1da177e4 LT |
1185 | writew(status & ~(UART011_TXIS|UART011_RTIS| |
1186 | UART011_RXIS), | |
1187 | uap->port.membase + UART011_ICR); | |
1188 | ||
ead76f32 LW |
1189 | if (status & (UART011_RTIS|UART011_RXIS)) { |
1190 | if (pl011_dma_rx_running(uap)) | |
1191 | pl011_dma_rx_irq(uap); | |
1192 | else | |
1193 | pl011_rx_chars(uap); | |
1194 | } | |
1da177e4 LT |
1195 | if (status & (UART011_DSRMIS|UART011_DCDMIS| |
1196 | UART011_CTSMIS|UART011_RIMIS)) | |
1197 | pl011_modem_status(uap); | |
1198 | if (status & UART011_TXIS) | |
1199 | pl011_tx_chars(uap); | |
1200 | ||
4fd0690b | 1201 | if (pass_counter-- == 0) |
1da177e4 LT |
1202 | break; |
1203 | ||
1204 | status = readw(uap->port.membase + UART011_MIS); | |
1205 | } while (status != 0); | |
1206 | handled = 1; | |
1207 | } | |
1208 | ||
963cc981 | 1209 | spin_unlock_irqrestore(&uap->port.lock, flags); |
1da177e4 LT |
1210 | |
1211 | return IRQ_RETVAL(handled); | |
1212 | } | |
1213 | ||
1214 | static unsigned int pl01x_tx_empty(struct uart_port *port) | |
1215 | { | |
1216 | struct uart_amba_port *uap = (struct uart_amba_port *)port; | |
1217 | unsigned int status = readw(uap->port.membase + UART01x_FR); | |
1218 | return status & (UART01x_FR_BUSY|UART01x_FR_TXFF) ? 0 : TIOCSER_TEMT; | |
1219 | } | |
1220 | ||
1221 | static unsigned int pl01x_get_mctrl(struct uart_port *port) | |
1222 | { | |
1223 | struct uart_amba_port *uap = (struct uart_amba_port *)port; | |
1224 | unsigned int result = 0; | |
1225 | unsigned int status = readw(uap->port.membase + UART01x_FR); | |
1226 | ||
5159f407 | 1227 | #define TIOCMBIT(uartbit, tiocmbit) \ |
1da177e4 LT |
1228 | if (status & uartbit) \ |
1229 | result |= tiocmbit | |
1230 | ||
5159f407 JS |
1231 | TIOCMBIT(UART01x_FR_DCD, TIOCM_CAR); |
1232 | TIOCMBIT(UART01x_FR_DSR, TIOCM_DSR); | |
1233 | TIOCMBIT(UART01x_FR_CTS, TIOCM_CTS); | |
1234 | TIOCMBIT(UART011_FR_RI, TIOCM_RNG); | |
1235 | #undef TIOCMBIT | |
1da177e4 LT |
1236 | return result; |
1237 | } | |
1238 | ||
1239 | static void pl011_set_mctrl(struct uart_port *port, unsigned int mctrl) | |
1240 | { | |
1241 | struct uart_amba_port *uap = (struct uart_amba_port *)port; | |
1242 | unsigned int cr; | |
1243 | ||
1244 | cr = readw(uap->port.membase + UART011_CR); | |
1245 | ||
5159f407 | 1246 | #define TIOCMBIT(tiocmbit, uartbit) \ |
1da177e4 LT |
1247 | if (mctrl & tiocmbit) \ |
1248 | cr |= uartbit; \ | |
1249 | else \ | |
1250 | cr &= ~uartbit | |
1251 | ||
5159f407 JS |
1252 | TIOCMBIT(TIOCM_RTS, UART011_CR_RTS); |
1253 | TIOCMBIT(TIOCM_DTR, UART011_CR_DTR); | |
1254 | TIOCMBIT(TIOCM_OUT1, UART011_CR_OUT1); | |
1255 | TIOCMBIT(TIOCM_OUT2, UART011_CR_OUT2); | |
1256 | TIOCMBIT(TIOCM_LOOP, UART011_CR_LBE); | |
3b43816f RV |
1257 | |
1258 | if (uap->autorts) { | |
1259 | /* We need to disable auto-RTS if we want to turn RTS off */ | |
1260 | TIOCMBIT(TIOCM_RTS, UART011_CR_RTSEN); | |
1261 | } | |
5159f407 | 1262 | #undef TIOCMBIT |
1da177e4 LT |
1263 | |
1264 | writew(cr, uap->port.membase + UART011_CR); | |
1265 | } | |
1266 | ||
1267 | static void pl011_break_ctl(struct uart_port *port, int break_state) | |
1268 | { | |
1269 | struct uart_amba_port *uap = (struct uart_amba_port *)port; | |
1270 | unsigned long flags; | |
1271 | unsigned int lcr_h; | |
1272 | ||
1273 | spin_lock_irqsave(&uap->port.lock, flags); | |
ec489aa8 | 1274 | lcr_h = readw(uap->port.membase + uap->lcrh_tx); |
1da177e4 LT |
1275 | if (break_state == -1) |
1276 | lcr_h |= UART01x_LCRH_BRK; | |
1277 | else | |
1278 | lcr_h &= ~UART01x_LCRH_BRK; | |
ec489aa8 | 1279 | writew(lcr_h, uap->port.membase + uap->lcrh_tx); |
1da177e4 LT |
1280 | spin_unlock_irqrestore(&uap->port.lock, flags); |
1281 | } | |
1282 | ||
84b5ae15 JW |
1283 | #ifdef CONFIG_CONSOLE_POLL |
1284 | static int pl010_get_poll_char(struct uart_port *port) | |
1285 | { | |
1286 | struct uart_amba_port *uap = (struct uart_amba_port *)port; | |
1287 | unsigned int status; | |
1288 | ||
f5316b4a JW |
1289 | status = readw(uap->port.membase + UART01x_FR); |
1290 | if (status & UART01x_FR_RXFE) | |
1291 | return NO_POLL_CHAR; | |
84b5ae15 JW |
1292 | |
1293 | return readw(uap->port.membase + UART01x_DR); | |
1294 | } | |
1295 | ||
1296 | static void pl010_put_poll_char(struct uart_port *port, | |
1297 | unsigned char ch) | |
1298 | { | |
1299 | struct uart_amba_port *uap = (struct uart_amba_port *)port; | |
1300 | ||
1301 | while (readw(uap->port.membase + UART01x_FR) & UART01x_FR_TXFF) | |
1302 | barrier(); | |
1303 | ||
1304 | writew(ch, uap->port.membase + UART01x_DR); | |
1305 | } | |
1306 | ||
1307 | #endif /* CONFIG_CONSOLE_POLL */ | |
1308 | ||
1da177e4 LT |
1309 | static int pl011_startup(struct uart_port *port) |
1310 | { | |
1311 | struct uart_amba_port *uap = (struct uart_amba_port *)port; | |
1312 | unsigned int cr; | |
1313 | int retval; | |
1314 | ||
4b4851c6 RK |
1315 | retval = clk_prepare(uap->clk); |
1316 | if (retval) | |
1317 | goto out; | |
1318 | ||
1da177e4 LT |
1319 | /* |
1320 | * Try to enable the clock producer. | |
1321 | */ | |
1322 | retval = clk_enable(uap->clk); | |
1323 | if (retval) | |
4b4851c6 | 1324 | goto clk_unprep; |
1da177e4 LT |
1325 | |
1326 | uap->port.uartclk = clk_get_rate(uap->clk); | |
1327 | ||
9b96fbac LW |
1328 | /* Clear pending error and receive interrupts */ |
1329 | writew(UART011_OEIS | UART011_BEIS | UART011_PEIS | UART011_FEIS | | |
1330 | UART011_RTIS | UART011_RXIS, uap->port.membase + UART011_ICR); | |
1331 | ||
1da177e4 LT |
1332 | /* |
1333 | * Allocate the IRQ | |
1334 | */ | |
1335 | retval = request_irq(uap->port.irq, pl011_int, 0, "uart-pl011", uap); | |
1336 | if (retval) | |
1337 | goto clk_dis; | |
1338 | ||
c19f12b5 | 1339 | writew(uap->vendor->ifls, uap->port.membase + UART011_IFLS); |
1da177e4 LT |
1340 | |
1341 | /* | |
1342 | * Provoke TX FIFO interrupt into asserting. | |
1343 | */ | |
1344 | cr = UART01x_CR_UARTEN | UART011_CR_TXE | UART011_CR_LBE; | |
1345 | writew(cr, uap->port.membase + UART011_CR); | |
1346 | writew(0, uap->port.membase + UART011_FBRD); | |
1347 | writew(1, uap->port.membase + UART011_IBRD); | |
ec489aa8 LW |
1348 | writew(0, uap->port.membase + uap->lcrh_rx); |
1349 | if (uap->lcrh_tx != uap->lcrh_rx) { | |
1350 | int i; | |
1351 | /* | |
1352 | * Wait 10 PCLKs before writing LCRH_TX register, | |
1353 | * to get this delay write read only register 10 times | |
1354 | */ | |
1355 | for (i = 0; i < 10; ++i) | |
1356 | writew(0xff, uap->port.membase + UART011_MIS); | |
1357 | writew(0, uap->port.membase + uap->lcrh_tx); | |
1358 | } | |
1da177e4 LT |
1359 | writew(0, uap->port.membase + UART01x_DR); |
1360 | while (readw(uap->port.membase + UART01x_FR) & UART01x_FR_BUSY) | |
1361 | barrier(); | |
1362 | ||
d8d8ffa4 SKS |
1363 | /* restore RTS and DTR */ |
1364 | cr = uap->old_cr & (UART011_CR_RTS | UART011_CR_DTR); | |
1365 | cr |= UART01x_CR_UARTEN | UART011_CR_RXE | UART011_CR_TXE; | |
1da177e4 LT |
1366 | writew(cr, uap->port.membase + UART011_CR); |
1367 | ||
1368 | /* | |
1369 | * initialise the old status of the modem signals | |
1370 | */ | |
1371 | uap->old_status = readw(uap->port.membase + UART01x_FR) & UART01x_FR_MODEM_ANY; | |
1372 | ||
68b65f73 RK |
1373 | /* Startup DMA */ |
1374 | pl011_dma_startup(uap); | |
1375 | ||
1da177e4 | 1376 | /* |
ead76f32 LW |
1377 | * Finally, enable interrupts, only timeouts when using DMA |
1378 | * if initial RX DMA job failed, start in interrupt mode | |
1379 | * as well. | |
1da177e4 LT |
1380 | */ |
1381 | spin_lock_irq(&uap->port.lock); | |
9b96fbac LW |
1382 | /* Clear out any spuriously appearing RX interrupts */ |
1383 | writew(UART011_RTIS | UART011_RXIS, | |
1384 | uap->port.membase + UART011_ICR); | |
ead76f32 LW |
1385 | uap->im = UART011_RTIM; |
1386 | if (!pl011_dma_rx_running(uap)) | |
1387 | uap->im |= UART011_RXIM; | |
1da177e4 LT |
1388 | writew(uap->im, uap->port.membase + UART011_IMSC); |
1389 | spin_unlock_irq(&uap->port.lock); | |
1390 | ||
c16d51a3 SKS |
1391 | if (uap->port.dev->platform_data) { |
1392 | struct amba_pl011_data *plat; | |
1393 | ||
1394 | plat = uap->port.dev->platform_data; | |
1395 | if (plat->init) | |
1396 | plat->init(); | |
1397 | } | |
1398 | ||
1da177e4 LT |
1399 | return 0; |
1400 | ||
1401 | clk_dis: | |
1402 | clk_disable(uap->clk); | |
4b4851c6 RK |
1403 | clk_unprep: |
1404 | clk_unprepare(uap->clk); | |
1da177e4 LT |
1405 | out: |
1406 | return retval; | |
1407 | } | |
1408 | ||
ec489aa8 LW |
1409 | static void pl011_shutdown_channel(struct uart_amba_port *uap, |
1410 | unsigned int lcrh) | |
1411 | { | |
1412 | unsigned long val; | |
1413 | ||
1414 | val = readw(uap->port.membase + lcrh); | |
1415 | val &= ~(UART01x_LCRH_BRK | UART01x_LCRH_FEN); | |
1416 | writew(val, uap->port.membase + lcrh); | |
1417 | } | |
1418 | ||
1da177e4 LT |
1419 | static void pl011_shutdown(struct uart_port *port) |
1420 | { | |
1421 | struct uart_amba_port *uap = (struct uart_amba_port *)port; | |
d8d8ffa4 | 1422 | unsigned int cr; |
1da177e4 LT |
1423 | |
1424 | /* | |
1425 | * disable all interrupts | |
1426 | */ | |
1427 | spin_lock_irq(&uap->port.lock); | |
1428 | uap->im = 0; | |
1429 | writew(uap->im, uap->port.membase + UART011_IMSC); | |
1430 | writew(0xffff, uap->port.membase + UART011_ICR); | |
1431 | spin_unlock_irq(&uap->port.lock); | |
1432 | ||
68b65f73 RK |
1433 | pl011_dma_shutdown(uap); |
1434 | ||
1da177e4 LT |
1435 | /* |
1436 | * Free the interrupt | |
1437 | */ | |
1438 | free_irq(uap->port.irq, uap); | |
1439 | ||
1440 | /* | |
1441 | * disable the port | |
d8d8ffa4 SKS |
1442 | * disable the port. It should not disable RTS and DTR. |
1443 | * Also RTS and DTR state should be preserved to restore | |
1444 | * it during startup(). | |
1da177e4 | 1445 | */ |
3b43816f | 1446 | uap->autorts = false; |
d8d8ffa4 SKS |
1447 | cr = readw(uap->port.membase + UART011_CR); |
1448 | uap->old_cr = cr; | |
1449 | cr &= UART011_CR_RTS | UART011_CR_DTR; | |
1450 | cr |= UART01x_CR_UARTEN | UART011_CR_TXE; | |
1451 | writew(cr, uap->port.membase + UART011_CR); | |
1da177e4 LT |
1452 | |
1453 | /* | |
1454 | * disable break condition and fifos | |
1455 | */ | |
ec489aa8 LW |
1456 | pl011_shutdown_channel(uap, uap->lcrh_rx); |
1457 | if (uap->lcrh_rx != uap->lcrh_tx) | |
1458 | pl011_shutdown_channel(uap, uap->lcrh_tx); | |
1da177e4 LT |
1459 | |
1460 | /* | |
1461 | * Shut down the clock producer | |
1462 | */ | |
1463 | clk_disable(uap->clk); | |
4b4851c6 | 1464 | clk_unprepare(uap->clk); |
c16d51a3 SKS |
1465 | |
1466 | if (uap->port.dev->platform_data) { | |
1467 | struct amba_pl011_data *plat; | |
1468 | ||
1469 | plat = uap->port.dev->platform_data; | |
1470 | if (plat->exit) | |
1471 | plat->exit(); | |
1472 | } | |
1473 | ||
1da177e4 LT |
1474 | } |
1475 | ||
1476 | static void | |
606d099c AC |
1477 | pl011_set_termios(struct uart_port *port, struct ktermios *termios, |
1478 | struct ktermios *old) | |
1da177e4 | 1479 | { |
3b43816f | 1480 | struct uart_amba_port *uap = (struct uart_amba_port *)port; |
1da177e4 LT |
1481 | unsigned int lcr_h, old_cr; |
1482 | unsigned long flags; | |
c19f12b5 RK |
1483 | unsigned int baud, quot, clkdiv; |
1484 | ||
1485 | if (uap->vendor->oversampling) | |
1486 | clkdiv = 8; | |
1487 | else | |
1488 | clkdiv = 16; | |
1da177e4 LT |
1489 | |
1490 | /* | |
1491 | * Ask the core to calculate the divisor for us. | |
1492 | */ | |
ac3e3fb4 | 1493 | baud = uart_get_baud_rate(port, termios, old, 0, |
c19f12b5 | 1494 | port->uartclk / clkdiv); |
ac3e3fb4 LW |
1495 | |
1496 | if (baud > port->uartclk/16) | |
1497 | quot = DIV_ROUND_CLOSEST(port->uartclk * 8, baud); | |
1498 | else | |
1499 | quot = DIV_ROUND_CLOSEST(port->uartclk * 4, baud); | |
1da177e4 LT |
1500 | |
1501 | switch (termios->c_cflag & CSIZE) { | |
1502 | case CS5: | |
1503 | lcr_h = UART01x_LCRH_WLEN_5; | |
1504 | break; | |
1505 | case CS6: | |
1506 | lcr_h = UART01x_LCRH_WLEN_6; | |
1507 | break; | |
1508 | case CS7: | |
1509 | lcr_h = UART01x_LCRH_WLEN_7; | |
1510 | break; | |
1511 | default: // CS8 | |
1512 | lcr_h = UART01x_LCRH_WLEN_8; | |
1513 | break; | |
1514 | } | |
1515 | if (termios->c_cflag & CSTOPB) | |
1516 | lcr_h |= UART01x_LCRH_STP2; | |
1517 | if (termios->c_cflag & PARENB) { | |
1518 | lcr_h |= UART01x_LCRH_PEN; | |
1519 | if (!(termios->c_cflag & PARODD)) | |
1520 | lcr_h |= UART01x_LCRH_EPS; | |
1521 | } | |
ffca2b11 | 1522 | if (uap->fifosize > 1) |
1da177e4 LT |
1523 | lcr_h |= UART01x_LCRH_FEN; |
1524 | ||
1525 | spin_lock_irqsave(&port->lock, flags); | |
1526 | ||
1527 | /* | |
1528 | * Update the per-port timeout. | |
1529 | */ | |
1530 | uart_update_timeout(port, termios->c_cflag, baud); | |
1531 | ||
b63d4f0f | 1532 | port->read_status_mask = UART011_DR_OE | 255; |
1da177e4 | 1533 | if (termios->c_iflag & INPCK) |
b63d4f0f | 1534 | port->read_status_mask |= UART011_DR_FE | UART011_DR_PE; |
1da177e4 | 1535 | if (termios->c_iflag & (BRKINT | PARMRK)) |
b63d4f0f | 1536 | port->read_status_mask |= UART011_DR_BE; |
1da177e4 LT |
1537 | |
1538 | /* | |
1539 | * Characters to ignore | |
1540 | */ | |
1541 | port->ignore_status_mask = 0; | |
1542 | if (termios->c_iflag & IGNPAR) | |
b63d4f0f | 1543 | port->ignore_status_mask |= UART011_DR_FE | UART011_DR_PE; |
1da177e4 | 1544 | if (termios->c_iflag & IGNBRK) { |
b63d4f0f | 1545 | port->ignore_status_mask |= UART011_DR_BE; |
1da177e4 LT |
1546 | /* |
1547 | * If we're ignoring parity and break indicators, | |
1548 | * ignore overruns too (for real raw support). | |
1549 | */ | |
1550 | if (termios->c_iflag & IGNPAR) | |
b63d4f0f | 1551 | port->ignore_status_mask |= UART011_DR_OE; |
1da177e4 LT |
1552 | } |
1553 | ||
1554 | /* | |
1555 | * Ignore all characters if CREAD is not set. | |
1556 | */ | |
1557 | if ((termios->c_cflag & CREAD) == 0) | |
b63d4f0f | 1558 | port->ignore_status_mask |= UART_DUMMY_DR_RX; |
1da177e4 LT |
1559 | |
1560 | if (UART_ENABLE_MS(port, termios->c_cflag)) | |
1561 | pl011_enable_ms(port); | |
1562 | ||
1563 | /* first, disable everything */ | |
1564 | old_cr = readw(port->membase + UART011_CR); | |
1565 | writew(0, port->membase + UART011_CR); | |
1566 | ||
3b43816f RV |
1567 | if (termios->c_cflag & CRTSCTS) { |
1568 | if (old_cr & UART011_CR_RTS) | |
1569 | old_cr |= UART011_CR_RTSEN; | |
1570 | ||
1571 | old_cr |= UART011_CR_CTSEN; | |
1572 | uap->autorts = true; | |
1573 | } else { | |
1574 | old_cr &= ~(UART011_CR_CTSEN | UART011_CR_RTSEN); | |
1575 | uap->autorts = false; | |
1576 | } | |
1577 | ||
c19f12b5 RK |
1578 | if (uap->vendor->oversampling) { |
1579 | if (baud > port->uartclk / 16) | |
ac3e3fb4 LW |
1580 | old_cr |= ST_UART011_CR_OVSFACT; |
1581 | else | |
1582 | old_cr &= ~ST_UART011_CR_OVSFACT; | |
1583 | } | |
1584 | ||
1da177e4 LT |
1585 | /* Set baud rate */ |
1586 | writew(quot & 0x3f, port->membase + UART011_FBRD); | |
1587 | writew(quot >> 6, port->membase + UART011_IBRD); | |
1588 | ||
1589 | /* | |
1590 | * ----------v----------v----------v----------v----- | |
1591 | * NOTE: MUST BE WRITTEN AFTER UARTLCR_M & UARTLCR_L | |
1592 | * ----------^----------^----------^----------^----- | |
1593 | */ | |
ec489aa8 LW |
1594 | writew(lcr_h, port->membase + uap->lcrh_rx); |
1595 | if (uap->lcrh_rx != uap->lcrh_tx) { | |
1596 | int i; | |
1597 | /* | |
1598 | * Wait 10 PCLKs before writing LCRH_TX register, | |
1599 | * to get this delay write read only register 10 times | |
1600 | */ | |
1601 | for (i = 0; i < 10; ++i) | |
1602 | writew(0xff, uap->port.membase + UART011_MIS); | |
1603 | writew(lcr_h, port->membase + uap->lcrh_tx); | |
1604 | } | |
1da177e4 LT |
1605 | writew(old_cr, port->membase + UART011_CR); |
1606 | ||
1607 | spin_unlock_irqrestore(&port->lock, flags); | |
1608 | } | |
1609 | ||
1610 | static const char *pl011_type(struct uart_port *port) | |
1611 | { | |
e8a7ba86 RK |
1612 | struct uart_amba_port *uap = (struct uart_amba_port *)port; |
1613 | return uap->port.type == PORT_AMBA ? uap->type : NULL; | |
1da177e4 LT |
1614 | } |
1615 | ||
1616 | /* | |
1617 | * Release the memory region(s) being used by 'port' | |
1618 | */ | |
1619 | static void pl010_release_port(struct uart_port *port) | |
1620 | { | |
1621 | release_mem_region(port->mapbase, SZ_4K); | |
1622 | } | |
1623 | ||
1624 | /* | |
1625 | * Request the memory region(s) being used by 'port' | |
1626 | */ | |
1627 | static int pl010_request_port(struct uart_port *port) | |
1628 | { | |
1629 | return request_mem_region(port->mapbase, SZ_4K, "uart-pl011") | |
1630 | != NULL ? 0 : -EBUSY; | |
1631 | } | |
1632 | ||
1633 | /* | |
1634 | * Configure/autoconfigure the port. | |
1635 | */ | |
1636 | static void pl010_config_port(struct uart_port *port, int flags) | |
1637 | { | |
1638 | if (flags & UART_CONFIG_TYPE) { | |
1639 | port->type = PORT_AMBA; | |
1640 | pl010_request_port(port); | |
1641 | } | |
1642 | } | |
1643 | ||
1644 | /* | |
1645 | * verify the new serial_struct (for TIOCSSERIAL). | |
1646 | */ | |
1647 | static int pl010_verify_port(struct uart_port *port, struct serial_struct *ser) | |
1648 | { | |
1649 | int ret = 0; | |
1650 | if (ser->type != PORT_UNKNOWN && ser->type != PORT_AMBA) | |
1651 | ret = -EINVAL; | |
a62c4133 | 1652 | if (ser->irq < 0 || ser->irq >= nr_irqs) |
1da177e4 LT |
1653 | ret = -EINVAL; |
1654 | if (ser->baud_base < 9600) | |
1655 | ret = -EINVAL; | |
1656 | return ret; | |
1657 | } | |
1658 | ||
1659 | static struct uart_ops amba_pl011_pops = { | |
1660 | .tx_empty = pl01x_tx_empty, | |
1661 | .set_mctrl = pl011_set_mctrl, | |
1662 | .get_mctrl = pl01x_get_mctrl, | |
1663 | .stop_tx = pl011_stop_tx, | |
1664 | .start_tx = pl011_start_tx, | |
1665 | .stop_rx = pl011_stop_rx, | |
1666 | .enable_ms = pl011_enable_ms, | |
1667 | .break_ctl = pl011_break_ctl, | |
1668 | .startup = pl011_startup, | |
1669 | .shutdown = pl011_shutdown, | |
68b65f73 | 1670 | .flush_buffer = pl011_dma_flush_buffer, |
1da177e4 LT |
1671 | .set_termios = pl011_set_termios, |
1672 | .type = pl011_type, | |
1673 | .release_port = pl010_release_port, | |
1674 | .request_port = pl010_request_port, | |
1675 | .config_port = pl010_config_port, | |
1676 | .verify_port = pl010_verify_port, | |
84b5ae15 JW |
1677 | #ifdef CONFIG_CONSOLE_POLL |
1678 | .poll_get_char = pl010_get_poll_char, | |
1679 | .poll_put_char = pl010_put_poll_char, | |
1680 | #endif | |
1da177e4 LT |
1681 | }; |
1682 | ||
1683 | static struct uart_amba_port *amba_ports[UART_NR]; | |
1684 | ||
1685 | #ifdef CONFIG_SERIAL_AMBA_PL011_CONSOLE | |
1686 | ||
d358788f | 1687 | static void pl011_console_putchar(struct uart_port *port, int ch) |
1da177e4 | 1688 | { |
d358788f | 1689 | struct uart_amba_port *uap = (struct uart_amba_port *)port; |
1da177e4 | 1690 | |
d358788f RK |
1691 | while (readw(uap->port.membase + UART01x_FR) & UART01x_FR_TXFF) |
1692 | barrier(); | |
1da177e4 LT |
1693 | writew(ch, uap->port.membase + UART01x_DR); |
1694 | } | |
1695 | ||
1696 | static void | |
1697 | pl011_console_write(struct console *co, const char *s, unsigned int count) | |
1698 | { | |
1699 | struct uart_amba_port *uap = amba_ports[co->index]; | |
1700 | unsigned int status, old_cr, new_cr; | |
ef605fdb RV |
1701 | unsigned long flags; |
1702 | int locked = 1; | |
1da177e4 LT |
1703 | |
1704 | clk_enable(uap->clk); | |
1705 | ||
ef605fdb RV |
1706 | local_irq_save(flags); |
1707 | if (uap->port.sysrq) | |
1708 | locked = 0; | |
1709 | else if (oops_in_progress) | |
1710 | locked = spin_trylock(&uap->port.lock); | |
1711 | else | |
1712 | spin_lock(&uap->port.lock); | |
1713 | ||
1da177e4 LT |
1714 | /* |
1715 | * First save the CR then disable the interrupts | |
1716 | */ | |
1717 | old_cr = readw(uap->port.membase + UART011_CR); | |
1718 | new_cr = old_cr & ~UART011_CR_CTSEN; | |
1719 | new_cr |= UART01x_CR_UARTEN | UART011_CR_TXE; | |
1720 | writew(new_cr, uap->port.membase + UART011_CR); | |
1721 | ||
d358788f | 1722 | uart_console_write(&uap->port, s, count, pl011_console_putchar); |
1da177e4 LT |
1723 | |
1724 | /* | |
1725 | * Finally, wait for transmitter to become empty | |
1726 | * and restore the TCR | |
1727 | */ | |
1728 | do { | |
1729 | status = readw(uap->port.membase + UART01x_FR); | |
1730 | } while (status & UART01x_FR_BUSY); | |
1731 | writew(old_cr, uap->port.membase + UART011_CR); | |
1732 | ||
ef605fdb RV |
1733 | if (locked) |
1734 | spin_unlock(&uap->port.lock); | |
1735 | local_irq_restore(flags); | |
1736 | ||
1da177e4 LT |
1737 | clk_disable(uap->clk); |
1738 | } | |
1739 | ||
1740 | static void __init | |
1741 | pl011_console_get_options(struct uart_amba_port *uap, int *baud, | |
1742 | int *parity, int *bits) | |
1743 | { | |
1744 | if (readw(uap->port.membase + UART011_CR) & UART01x_CR_UARTEN) { | |
1745 | unsigned int lcr_h, ibrd, fbrd; | |
1746 | ||
ec489aa8 | 1747 | lcr_h = readw(uap->port.membase + uap->lcrh_tx); |
1da177e4 LT |
1748 | |
1749 | *parity = 'n'; | |
1750 | if (lcr_h & UART01x_LCRH_PEN) { | |
1751 | if (lcr_h & UART01x_LCRH_EPS) | |
1752 | *parity = 'e'; | |
1753 | else | |
1754 | *parity = 'o'; | |
1755 | } | |
1756 | ||
1757 | if ((lcr_h & 0x60) == UART01x_LCRH_WLEN_7) | |
1758 | *bits = 7; | |
1759 | else | |
1760 | *bits = 8; | |
1761 | ||
1762 | ibrd = readw(uap->port.membase + UART011_IBRD); | |
1763 | fbrd = readw(uap->port.membase + UART011_FBRD); | |
1764 | ||
1765 | *baud = uap->port.uartclk * 4 / (64 * ibrd + fbrd); | |
ac3e3fb4 | 1766 | |
c19f12b5 | 1767 | if (uap->vendor->oversampling) { |
ac3e3fb4 LW |
1768 | if (readw(uap->port.membase + UART011_CR) |
1769 | & ST_UART011_CR_OVSFACT) | |
1770 | *baud *= 2; | |
1771 | } | |
1da177e4 LT |
1772 | } |
1773 | } | |
1774 | ||
1775 | static int __init pl011_console_setup(struct console *co, char *options) | |
1776 | { | |
1777 | struct uart_amba_port *uap; | |
1778 | int baud = 38400; | |
1779 | int bits = 8; | |
1780 | int parity = 'n'; | |
1781 | int flow = 'n'; | |
4b4851c6 | 1782 | int ret; |
1da177e4 LT |
1783 | |
1784 | /* | |
1785 | * Check whether an invalid uart number has been specified, and | |
1786 | * if so, search for the first available port that does have | |
1787 | * console support. | |
1788 | */ | |
1789 | if (co->index >= UART_NR) | |
1790 | co->index = 0; | |
1791 | uap = amba_ports[co->index]; | |
d28122a5 RK |
1792 | if (!uap) |
1793 | return -ENODEV; | |
1da177e4 | 1794 | |
4b4851c6 RK |
1795 | ret = clk_prepare(uap->clk); |
1796 | if (ret) | |
1797 | return ret; | |
1798 | ||
c16d51a3 SKS |
1799 | if (uap->port.dev->platform_data) { |
1800 | struct amba_pl011_data *plat; | |
1801 | ||
1802 | plat = uap->port.dev->platform_data; | |
1803 | if (plat->init) | |
1804 | plat->init(); | |
1805 | } | |
1806 | ||
1da177e4 LT |
1807 | uap->port.uartclk = clk_get_rate(uap->clk); |
1808 | ||
1809 | if (options) | |
1810 | uart_parse_options(options, &baud, &parity, &bits, &flow); | |
1811 | else | |
1812 | pl011_console_get_options(uap, &baud, &parity, &bits); | |
1813 | ||
1814 | return uart_set_options(&uap->port, co, baud, parity, bits, flow); | |
1815 | } | |
1816 | ||
2d93486c | 1817 | static struct uart_driver amba_reg; |
1da177e4 LT |
1818 | static struct console amba_console = { |
1819 | .name = "ttyAMA", | |
1820 | .write = pl011_console_write, | |
1821 | .device = uart_console_device, | |
1822 | .setup = pl011_console_setup, | |
1823 | .flags = CON_PRINTBUFFER, | |
1824 | .index = -1, | |
1825 | .data = &amba_reg, | |
1826 | }; | |
1827 | ||
1828 | #define AMBA_CONSOLE (&amba_console) | |
1829 | #else | |
1830 | #define AMBA_CONSOLE NULL | |
1831 | #endif | |
1832 | ||
1833 | static struct uart_driver amba_reg = { | |
1834 | .owner = THIS_MODULE, | |
1835 | .driver_name = "ttyAMA", | |
1836 | .dev_name = "ttyAMA", | |
1837 | .major = SERIAL_AMBA_MAJOR, | |
1838 | .minor = SERIAL_AMBA_MINOR, | |
1839 | .nr = UART_NR, | |
1840 | .cons = AMBA_CONSOLE, | |
1841 | }; | |
1842 | ||
aa25afad | 1843 | static int pl011_probe(struct amba_device *dev, const struct amba_id *id) |
1da177e4 LT |
1844 | { |
1845 | struct uart_amba_port *uap; | |
5926a295 | 1846 | struct vendor_data *vendor = id->data; |
258e0551 | 1847 | struct pinctrl *pinctrl; |
1da177e4 LT |
1848 | void __iomem *base; |
1849 | int i, ret; | |
1850 | ||
1851 | for (i = 0; i < ARRAY_SIZE(amba_ports); i++) | |
1852 | if (amba_ports[i] == NULL) | |
1853 | break; | |
1854 | ||
1855 | if (i == ARRAY_SIZE(amba_ports)) { | |
1856 | ret = -EBUSY; | |
1857 | goto out; | |
1858 | } | |
1859 | ||
dd00cc48 | 1860 | uap = kzalloc(sizeof(struct uart_amba_port), GFP_KERNEL); |
1da177e4 LT |
1861 | if (uap == NULL) { |
1862 | ret = -ENOMEM; | |
1863 | goto out; | |
1864 | } | |
1865 | ||
dc890c2d | 1866 | base = ioremap(dev->res.start, resource_size(&dev->res)); |
1da177e4 LT |
1867 | if (!base) { |
1868 | ret = -ENOMEM; | |
1869 | goto free; | |
1870 | } | |
1871 | ||
258e0551 SG |
1872 | pinctrl = devm_pinctrl_get_select_default(&dev->dev); |
1873 | if (IS_ERR(pinctrl)) { | |
1874 | ret = PTR_ERR(pinctrl); | |
1875 | goto unmap; | |
1876 | } | |
1877 | ||
ee569c43 | 1878 | uap->clk = clk_get(&dev->dev, NULL); |
1da177e4 LT |
1879 | if (IS_ERR(uap->clk)) { |
1880 | ret = PTR_ERR(uap->clk); | |
1881 | goto unmap; | |
1882 | } | |
1883 | ||
c19f12b5 | 1884 | uap->vendor = vendor; |
ec489aa8 LW |
1885 | uap->lcrh_rx = vendor->lcrh_rx; |
1886 | uap->lcrh_tx = vendor->lcrh_tx; | |
d8d8ffa4 | 1887 | uap->old_cr = 0; |
ffca2b11 | 1888 | uap->fifosize = vendor->fifosize; |
c16d51a3 | 1889 | uap->interrupt_may_hang = vendor->interrupt_may_hang; |
1da177e4 LT |
1890 | uap->port.dev = &dev->dev; |
1891 | uap->port.mapbase = dev->res.start; | |
1892 | uap->port.membase = base; | |
1893 | uap->port.iotype = UPIO_MEM; | |
1894 | uap->port.irq = dev->irq[0]; | |
ffca2b11 | 1895 | uap->port.fifosize = uap->fifosize; |
1da177e4 LT |
1896 | uap->port.ops = &amba_pl011_pops; |
1897 | uap->port.flags = UPF_BOOT_AUTOCONF; | |
1898 | uap->port.line = i; | |
68b65f73 | 1899 | pl011_dma_probe(uap); |
1da177e4 | 1900 | |
c3d8b76f LW |
1901 | /* Ensure interrupts from this UART are masked and cleared */ |
1902 | writew(0, uap->port.membase + UART011_IMSC); | |
1903 | writew(0xffff, uap->port.membase + UART011_ICR); | |
1904 | ||
e8a7ba86 RK |
1905 | snprintf(uap->type, sizeof(uap->type), "PL011 rev%u", amba_rev(dev)); |
1906 | ||
1da177e4 LT |
1907 | amba_ports[i] = uap; |
1908 | ||
1909 | amba_set_drvdata(dev, uap); | |
1910 | ret = uart_add_one_port(&amba_reg, &uap->port); | |
1911 | if (ret) { | |
1912 | amba_set_drvdata(dev, NULL); | |
1913 | amba_ports[i] = NULL; | |
68b65f73 | 1914 | pl011_dma_remove(uap); |
1da177e4 LT |
1915 | clk_put(uap->clk); |
1916 | unmap: | |
1917 | iounmap(base); | |
1918 | free: | |
1919 | kfree(uap); | |
1920 | } | |
1921 | out: | |
1922 | return ret; | |
1923 | } | |
1924 | ||
1925 | static int pl011_remove(struct amba_device *dev) | |
1926 | { | |
1927 | struct uart_amba_port *uap = amba_get_drvdata(dev); | |
1928 | int i; | |
1929 | ||
1930 | amba_set_drvdata(dev, NULL); | |
1931 | ||
1932 | uart_remove_one_port(&amba_reg, &uap->port); | |
1933 | ||
1934 | for (i = 0; i < ARRAY_SIZE(amba_ports); i++) | |
1935 | if (amba_ports[i] == uap) | |
1936 | amba_ports[i] = NULL; | |
1937 | ||
68b65f73 | 1938 | pl011_dma_remove(uap); |
1da177e4 | 1939 | iounmap(uap->port.membase); |
1da177e4 LT |
1940 | clk_put(uap->clk); |
1941 | kfree(uap); | |
1942 | return 0; | |
1943 | } | |
1944 | ||
b736b89f LC |
1945 | #ifdef CONFIG_PM |
1946 | static int pl011_suspend(struct amba_device *dev, pm_message_t state) | |
1947 | { | |
1948 | struct uart_amba_port *uap = amba_get_drvdata(dev); | |
1949 | ||
1950 | if (!uap) | |
1951 | return -EINVAL; | |
1952 | ||
1953 | return uart_suspend_port(&amba_reg, &uap->port); | |
1954 | } | |
1955 | ||
1956 | static int pl011_resume(struct amba_device *dev) | |
1957 | { | |
1958 | struct uart_amba_port *uap = amba_get_drvdata(dev); | |
1959 | ||
1960 | if (!uap) | |
1961 | return -EINVAL; | |
1962 | ||
1963 | return uart_resume_port(&amba_reg, &uap->port); | |
1964 | } | |
1965 | #endif | |
1966 | ||
2c39c9e1 | 1967 | static struct amba_id pl011_ids[] = { |
1da177e4 LT |
1968 | { |
1969 | .id = 0x00041011, | |
1970 | .mask = 0x000fffff, | |
5926a295 AR |
1971 | .data = &vendor_arm, |
1972 | }, | |
1973 | { | |
1974 | .id = 0x00380802, | |
1975 | .mask = 0x00ffffff, | |
1976 | .data = &vendor_st, | |
1da177e4 LT |
1977 | }, |
1978 | { 0, 0 }, | |
1979 | }; | |
1980 | ||
60f7a33b DM |
1981 | MODULE_DEVICE_TABLE(amba, pl011_ids); |
1982 | ||
1da177e4 LT |
1983 | static struct amba_driver pl011_driver = { |
1984 | .drv = { | |
1985 | .name = "uart-pl011", | |
1986 | }, | |
1987 | .id_table = pl011_ids, | |
1988 | .probe = pl011_probe, | |
1989 | .remove = pl011_remove, | |
b736b89f LC |
1990 | #ifdef CONFIG_PM |
1991 | .suspend = pl011_suspend, | |
1992 | .resume = pl011_resume, | |
1993 | #endif | |
1da177e4 LT |
1994 | }; |
1995 | ||
1996 | static int __init pl011_init(void) | |
1997 | { | |
1998 | int ret; | |
1999 | printk(KERN_INFO "Serial: AMBA PL011 UART driver\n"); | |
2000 | ||
2001 | ret = uart_register_driver(&amba_reg); | |
2002 | if (ret == 0) { | |
2003 | ret = amba_driver_register(&pl011_driver); | |
2004 | if (ret) | |
2005 | uart_unregister_driver(&amba_reg); | |
2006 | } | |
2007 | return ret; | |
2008 | } | |
2009 | ||
2010 | static void __exit pl011_exit(void) | |
2011 | { | |
2012 | amba_driver_unregister(&pl011_driver); | |
2013 | uart_unregister_driver(&amba_reg); | |
2014 | } | |
2015 | ||
4dd9e742 AR |
2016 | /* |
2017 | * While this can be a module, if builtin it's most likely the console | |
2018 | * So let's leave module_exit but move module_init to an earlier place | |
2019 | */ | |
2020 | arch_initcall(pl011_init); | |
1da177e4 LT |
2021 | module_exit(pl011_exit); |
2022 | ||
2023 | MODULE_AUTHOR("ARM Ltd/Deep Blue Solutions Ltd"); | |
2024 | MODULE_DESCRIPTION("ARM AMBA serial port driver"); | |
2025 | MODULE_LICENSE("GPL"); |