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Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +02001/*
2 * 8250-core based driver for the OMAP internal UART
3 *
4 * based on omap-serial.c, Copyright (C) 2010 Texas Instruments.
5 *
6 * Copyright (C) 2014 Sebastian Andrzej Siewior
7 *
8 */
9
10#include <linux/device.h>
11#include <linux/io.h>
12#include <linux/module.h>
13#include <linux/serial_8250.h>
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +020014#include <linux/serial_reg.h>
Sebastian Andrzej Siewior77285242014-09-29 20:06:48 +020015#include <linux/tty_flip.h>
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +020016#include <linux/platform_device.h>
17#include <linux/slab.h>
18#include <linux/of.h>
Sekhar Nori4fcdff92015-07-14 13:32:06 +053019#include <linux/of_device.h>
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +020020#include <linux/of_gpio.h>
21#include <linux/of_irq.h>
22#include <linux/delay.h>
23#include <linux/pm_runtime.h>
24#include <linux/console.h>
25#include <linux/pm_qos.h>
Tony Lindgrena3e362f2015-06-09 23:35:00 -070026#include <linux/pm_wakeirq.h>
Sebastian Andrzej Siewior31a17132014-09-29 20:06:43 +020027#include <linux/dma-mapping.h>
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +020028
29#include "8250.h"
30
31#define DEFAULT_CLK_SPEED 48000000
32
33#define UART_ERRATA_i202_MDR1_ACCESS (1 << 0)
34#define OMAP_UART_WER_HAS_TX_WAKEUP (1 << 1)
Sebastian Andrzej Siewior31a17132014-09-29 20:06:43 +020035#define OMAP_DMA_TX_KICK (1 << 2)
Sekhar Noricdb929e2015-07-14 13:32:07 +053036/*
37 * See Advisory 21 in AM437x errata SPRZ408B, updated April 2015.
38 * The same errata is applicable to AM335x and DRA7x processors too.
39 */
40#define UART_ERRATA_CLOCK_DISABLE (1 << 3)
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +020041
42#define OMAP_UART_FCR_RX_TRIG 6
43#define OMAP_UART_FCR_TX_TRIG 4
44
45/* SCR register bitmasks */
46#define OMAP_UART_SCR_RX_TRIG_GRANU1_MASK (1 << 7)
47#define OMAP_UART_SCR_TX_TRIG_GRANU1_MASK (1 << 6)
48#define OMAP_UART_SCR_TX_EMPTY (1 << 3)
49#define OMAP_UART_SCR_DMAMODE_MASK (3 << 1)
50#define OMAP_UART_SCR_DMAMODE_1 (1 << 1)
51#define OMAP_UART_SCR_DMAMODE_CTL (1 << 0)
52
53/* MVR register bitmasks */
54#define OMAP_UART_MVR_SCHEME_SHIFT 30
55#define OMAP_UART_LEGACY_MVR_MAJ_MASK 0xf0
56#define OMAP_UART_LEGACY_MVR_MAJ_SHIFT 4
57#define OMAP_UART_LEGACY_MVR_MIN_MASK 0x0f
58#define OMAP_UART_MVR_MAJ_MASK 0x700
59#define OMAP_UART_MVR_MAJ_SHIFT 8
60#define OMAP_UART_MVR_MIN_MASK 0x3f
61
Sekhar Noricdb929e2015-07-14 13:32:07 +053062/* SYSC register bitmasks */
63#define OMAP_UART_SYSC_SOFTRESET (1 << 1)
64
65/* SYSS register bitmasks */
66#define OMAP_UART_SYSS_RESETDONE (1 << 0)
67
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +020068#define UART_TI752_TLR_TX 0
69#define UART_TI752_TLR_RX 4
70
71#define TRIGGER_TLR_MASK(x) ((x & 0x3c) >> 2)
72#define TRIGGER_FCR_MASK(x) (x & 3)
73
74/* Enable XON/XOFF flow control on output */
75#define OMAP_UART_SW_TX 0x08
76/* Enable XON/XOFF flow control on input */
77#define OMAP_UART_SW_RX 0x02
78
79#define OMAP_UART_WER_MOD_WKUP 0x7f
80#define OMAP_UART_TX_WAKEUP_EN (1 << 7)
81
82#define TX_TRIGGER 1
83#define RX_TRIGGER 48
84
85#define OMAP_UART_TCR_RESTORE(x) ((x / 4) << 4)
86#define OMAP_UART_TCR_HALT(x) ((x / 4) << 0)
87
88#define UART_BUILD_REVISION(x, y) (((x) << 8) | (y))
89
90#define OMAP_UART_REV_46 0x0406
91#define OMAP_UART_REV_52 0x0502
92#define OMAP_UART_REV_63 0x0603
93
94struct omap8250_priv {
95 int line;
96 u8 habit;
97 u8 mdr1;
98 u8 efr;
99 u8 scr;
100 u8 wer;
101 u8 xon;
102 u8 xoff;
Sebastian Andrzej Siewior0a0661d2014-09-29 20:06:49 +0200103 u8 delayed_restore;
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +0200104 u16 quot;
105
106 bool is_suspending;
107 int wakeirq;
108 int wakeups_enabled;
109 u32 latency;
110 u32 calc_latency;
111 struct pm_qos_request pm_qos_request;
112 struct work_struct qos_work;
113 struct uart_8250_dma omap8250_dma;
John Ognesseda0cd32015-04-27 13:52:33 +0200114 spinlock_t rx_dma_lock;
Sebastian Andrzej Siewior830acf92015-08-14 17:52:07 +0200115 bool rx_dma_broken;
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +0200116};
117
Peter Hurley33d9b8b22016-04-09 22:14:36 -0700118#ifdef CONFIG_SERIAL_8250_DMA
119static void omap_8250_rx_dma_flush(struct uart_8250_port *p);
120#else
121static inline void omap_8250_rx_dma_flush(struct uart_8250_port *p) { }
122#endif
123
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +0200124static u32 uart_read(struct uart_8250_port *up, u32 reg)
125{
126 return readl(up->port.membase + (reg << up->port.regshift));
127}
128
Peter Hurley4bf4ea92014-12-30 20:28:15 -0500129static void omap8250_set_mctrl(struct uart_port *port, unsigned int mctrl)
130{
131 struct uart_8250_port *up = up_to_u8250p(port);
132 struct omap8250_priv *priv = up->port.private_data;
133 u8 lcr;
134
135 serial8250_do_set_mctrl(port, mctrl);
136
Yegor Yefremov4ef03d32016-05-31 10:59:18 +0200137 if (IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(up->gpios,
138 UART_GPIO_RTS))) {
139 /*
140 * Turn off autoRTS if RTS is lowered and restore autoRTS
141 * setting if RTS is raised
142 */
143 lcr = serial_in(up, UART_LCR);
144 serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
145 if ((mctrl & TIOCM_RTS) && (port->status & UPSTAT_AUTORTS))
146 priv->efr |= UART_EFR_RTS;
147 else
148 priv->efr &= ~UART_EFR_RTS;
149 serial_out(up, UART_EFR, priv->efr);
150 serial_out(up, UART_LCR, lcr);
151 }
Peter Hurley4bf4ea92014-12-30 20:28:15 -0500152}
153
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +0200154/*
155 * Work Around for Errata i202 (2430, 3430, 3630, 4430 and 4460)
156 * The access to uart register after MDR1 Access
157 * causes UART to corrupt data.
158 *
159 * Need a delay =
160 * 5 L4 clock cycles + 5 UART functional clock cycle (@48MHz = ~0.2uS)
161 * give 10 times as much
162 */
163static void omap_8250_mdr1_errataset(struct uart_8250_port *up,
164 struct omap8250_priv *priv)
165{
166 u8 timeout = 255;
167 u8 old_mdr1;
168
169 old_mdr1 = serial_in(up, UART_OMAP_MDR1);
170 if (old_mdr1 == priv->mdr1)
171 return;
172
173 serial_out(up, UART_OMAP_MDR1, priv->mdr1);
174 udelay(2);
175 serial_out(up, UART_FCR, up->fcr | UART_FCR_CLEAR_XMIT |
176 UART_FCR_CLEAR_RCVR);
177 /*
178 * Wait for FIFO to empty: when empty, RX_FIFO_E bit is 0 and
179 * TX_FIFO_E bit is 1.
180 */
181 while (UART_LSR_THRE != (serial_in(up, UART_LSR) &
182 (UART_LSR_THRE | UART_LSR_DR))) {
183 timeout--;
184 if (!timeout) {
185 /* Should *never* happen. we warn and carry on */
186 dev_crit(up->port.dev, "Errata i202: timedout %x\n",
187 serial_in(up, UART_LSR));
188 break;
189 }
190 udelay(1);
191 }
192}
193
194static void omap_8250_get_divisor(struct uart_port *port, unsigned int baud,
195 struct omap8250_priv *priv)
196{
197 unsigned int uartclk = port->uartclk;
198 unsigned int div_13, div_16;
199 unsigned int abs_d13, abs_d16;
200
201 /*
202 * Old custom speed handling.
203 */
204 if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST) {
205 priv->quot = port->custom_divisor & 0xffff;
206 /*
207 * I assume that nobody is using this. But hey, if somebody
208 * would like to specify the divisor _and_ the mode then the
209 * driver is ready and waiting for it.
210 */
211 if (port->custom_divisor & (1 << 16))
212 priv->mdr1 = UART_OMAP_MDR1_13X_MODE;
213 else
214 priv->mdr1 = UART_OMAP_MDR1_16X_MODE;
215 return;
216 }
217 div_13 = DIV_ROUND_CLOSEST(uartclk, 13 * baud);
218 div_16 = DIV_ROUND_CLOSEST(uartclk, 16 * baud);
219
220 if (!div_13)
221 div_13 = 1;
222 if (!div_16)
223 div_16 = 1;
224
225 abs_d13 = abs(baud - uartclk / 13 / div_13);
226 abs_d16 = abs(baud - uartclk / 16 / div_16);
227
228 if (abs_d13 >= abs_d16) {
229 priv->mdr1 = UART_OMAP_MDR1_16X_MODE;
230 priv->quot = div_16;
231 } else {
232 priv->mdr1 = UART_OMAP_MDR1_13X_MODE;
233 priv->quot = div_13;
234 }
235}
236
237static void omap8250_update_scr(struct uart_8250_port *up,
238 struct omap8250_priv *priv)
239{
240 u8 old_scr;
241
242 old_scr = serial_in(up, UART_OMAP_SCR);
243 if (old_scr == priv->scr)
244 return;
245
246 /*
247 * The manual recommends not to enable the DMA mode selector in the SCR
248 * (instead of the FCR) register _and_ selecting the DMA mode as one
249 * register write because this may lead to malfunction.
250 */
251 if (priv->scr & OMAP_UART_SCR_DMAMODE_MASK)
252 serial_out(up, UART_OMAP_SCR,
253 priv->scr & ~OMAP_UART_SCR_DMAMODE_MASK);
254 serial_out(up, UART_OMAP_SCR, priv->scr);
255}
256
Sekhar Nori6f035412015-07-14 13:32:05 +0530257static void omap8250_update_mdr1(struct uart_8250_port *up,
258 struct omap8250_priv *priv)
259{
260 if (priv->habit & UART_ERRATA_i202_MDR1_ACCESS)
261 omap_8250_mdr1_errataset(up, priv);
262 else
263 serial_out(up, UART_OMAP_MDR1, priv->mdr1);
264}
265
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +0200266static void omap8250_restore_regs(struct uart_8250_port *up)
267{
268 struct omap8250_priv *priv = up->port.private_data;
Sebastian Andrzej Siewior0a0661d2014-09-29 20:06:49 +0200269 struct uart_8250_dma *dma = up->dma;
270
271 if (dma && dma->tx_running) {
272 /*
273 * TCSANOW requests the change to occur immediately however if
274 * we have a TX-DMA operation in progress then it has been
275 * observed that it might stall and never complete. Therefore we
276 * delay DMA completes to prevent this hang from happen.
277 */
278 priv->delayed_restore = 1;
279 return;
280 }
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +0200281
282 serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
283 serial_out(up, UART_EFR, UART_EFR_ECB);
284
285 serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
Yegor Yefremov36fd95b2016-05-31 10:59:15 +0200286 serial8250_out_MCR(up, UART_MCR_TCRTLR);
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +0200287 serial_out(up, UART_FCR, up->fcr);
288
289 omap8250_update_scr(up, priv);
290
291 serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
292
293 serial_out(up, UART_TI752_TCR, OMAP_UART_TCR_RESTORE(16) |
294 OMAP_UART_TCR_HALT(52));
295 serial_out(up, UART_TI752_TLR,
296 TRIGGER_TLR_MASK(TX_TRIGGER) << UART_TI752_TLR_TX |
297 TRIGGER_TLR_MASK(RX_TRIGGER) << UART_TI752_TLR_RX);
298
299 serial_out(up, UART_LCR, 0);
300
301 /* drop TCR + TLR access, we setup XON/XOFF later */
Yegor Yefremov36fd95b2016-05-31 10:59:15 +0200302 serial8250_out_MCR(up, up->mcr);
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +0200303 serial_out(up, UART_IER, up->ier);
304
305 serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
306 serial_dl_write(up, priv->quot);
307
Peter Hurley9719acc2015-01-25 14:44:52 -0500308 serial_out(up, UART_EFR, priv->efr);
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +0200309
310 /* Configure flow control */
311 serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
312 serial_out(up, UART_XON1, priv->xon);
313 serial_out(up, UART_XOFF1, priv->xoff);
314
315 serial_out(up, UART_LCR, up->lcr);
Sekhar Nori6f035412015-07-14 13:32:05 +0530316
317 omap8250_update_mdr1(up, priv);
318
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +0200319 up->port.ops->set_mctrl(&up->port, up->port.mctrl);
320}
321
322/*
323 * OMAP can use "CLK / (16 or 13) / div" for baud rate. And then we have have
324 * some differences in how we want to handle flow control.
325 */
326static void omap_8250_set_termios(struct uart_port *port,
327 struct ktermios *termios,
328 struct ktermios *old)
329{
Andy Shevchenko013e3582016-02-18 21:22:59 +0200330 struct uart_8250_port *up = up_to_u8250p(port);
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +0200331 struct omap8250_priv *priv = up->port.private_data;
332 unsigned char cval = 0;
333 unsigned int baud;
334
335 switch (termios->c_cflag & CSIZE) {
336 case CS5:
337 cval = UART_LCR_WLEN5;
338 break;
339 case CS6:
340 cval = UART_LCR_WLEN6;
341 break;
342 case CS7:
343 cval = UART_LCR_WLEN7;
344 break;
345 default:
346 case CS8:
347 cval = UART_LCR_WLEN8;
348 break;
349 }
350
351 if (termios->c_cflag & CSTOPB)
352 cval |= UART_LCR_STOP;
353 if (termios->c_cflag & PARENB)
354 cval |= UART_LCR_PARITY;
355 if (!(termios->c_cflag & PARODD))
356 cval |= UART_LCR_EPAR;
357 if (termios->c_cflag & CMSPAR)
358 cval |= UART_LCR_SPAR;
359
360 /*
361 * Ask the core to calculate the divisor for us.
362 */
363 baud = uart_get_baud_rate(port, termios, old,
364 port->uartclk / 16 / 0xffff,
365 port->uartclk / 13);
366 omap_8250_get_divisor(port, baud, priv);
367
368 /*
369 * Ok, we're now changing the port state. Do it with
370 * interrupts disabled.
371 */
372 pm_runtime_get_sync(port->dev);
373 spin_lock_irq(&port->lock);
374
375 /*
376 * Update the per-port timeout.
377 */
378 uart_update_timeout(port, termios->c_cflag, baud);
379
380 up->port.read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
381 if (termios->c_iflag & INPCK)
382 up->port.read_status_mask |= UART_LSR_FE | UART_LSR_PE;
383 if (termios->c_iflag & (IGNBRK | PARMRK))
384 up->port.read_status_mask |= UART_LSR_BI;
385
386 /*
387 * Characters to ignore
388 */
389 up->port.ignore_status_mask = 0;
390 if (termios->c_iflag & IGNPAR)
391 up->port.ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
392 if (termios->c_iflag & IGNBRK) {
393 up->port.ignore_status_mask |= UART_LSR_BI;
394 /*
395 * If we're ignoring parity and break indicators,
396 * ignore overruns too (for real raw support).
397 */
398 if (termios->c_iflag & IGNPAR)
399 up->port.ignore_status_mask |= UART_LSR_OE;
400 }
401
402 /*
403 * ignore all characters if CREAD is not set
404 */
405 if ((termios->c_cflag & CREAD) == 0)
406 up->port.ignore_status_mask |= UART_LSR_DR;
407
408 /*
409 * Modem status interrupts
410 */
411 up->ier &= ~UART_IER_MSI;
412 if (UART_ENABLE_MS(&up->port, termios->c_cflag))
413 up->ier |= UART_IER_MSI;
414
415 up->lcr = cval;
416 /* Up to here it was mostly serial8250_do_set_termios() */
417
418 /*
419 * We enable TRIG_GRANU for RX and TX and additionaly we set
420 * SCR_TX_EMPTY bit. The result is the following:
421 * - RX_TRIGGER amount of bytes in the FIFO will cause an interrupt.
422 * - less than RX_TRIGGER number of bytes will also cause an interrupt
423 * once the UART decides that there no new bytes arriving.
424 * - Once THRE is enabled, the interrupt will be fired once the FIFO is
425 * empty - the trigger level is ignored here.
426 *
427 * Once DMA is enabled:
428 * - UART will assert the TX DMA line once there is room for TX_TRIGGER
429 * bytes in the TX FIFO. On each assert the DMA engine will move
430 * TX_TRIGGER bytes into the FIFO.
431 * - UART will assert the RX DMA line once there are RX_TRIGGER bytes in
432 * the FIFO and move RX_TRIGGER bytes.
433 * This is because threshold and trigger values are the same.
434 */
435 up->fcr = UART_FCR_ENABLE_FIFO;
436 up->fcr |= TRIGGER_FCR_MASK(TX_TRIGGER) << OMAP_UART_FCR_TX_TRIG;
437 up->fcr |= TRIGGER_FCR_MASK(RX_TRIGGER) << OMAP_UART_FCR_RX_TRIG;
438
439 priv->scr = OMAP_UART_SCR_RX_TRIG_GRANU1_MASK | OMAP_UART_SCR_TX_EMPTY |
440 OMAP_UART_SCR_TX_TRIG_GRANU1_MASK;
441
Sebastian Andrzej Siewior0a0661d2014-09-29 20:06:49 +0200442 if (up->dma)
443 priv->scr |= OMAP_UART_SCR_DMAMODE_1 |
444 OMAP_UART_SCR_DMAMODE_CTL;
445
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +0200446 priv->xon = termios->c_cc[VSTART];
447 priv->xoff = termios->c_cc[VSTOP];
448
449 priv->efr = 0;
Peter Hurley391f93f2015-01-25 14:44:51 -0500450 up->port.status &= ~(UPSTAT_AUTOCTS | UPSTAT_AUTORTS | UPSTAT_AUTOXOFF);
451
Yegor Yefremov4ef03d32016-05-31 10:59:18 +0200452 if (termios->c_cflag & CRTSCTS && up->port.flags & UPF_HARD_FLOW
453 && IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(up->gpios,
454 UART_GPIO_RTS))) {
Peter Hurley9719acc2015-01-25 14:44:52 -0500455 /* Enable AUTOCTS (autoRTS is enabled when RTS is raised) */
Peter Hurley391f93f2015-01-25 14:44:51 -0500456 up->port.status |= UPSTAT_AUTOCTS | UPSTAT_AUTORTS;
Peter Hurley9719acc2015-01-25 14:44:52 -0500457 priv->efr |= UART_EFR_CTS;
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +0200458 } else if (up->port.flags & UPF_SOFT_FLOW) {
459 /*
Peter Hurley5bac4b32015-06-27 09:28:55 -0400460 * OMAP rx s/w flow control is borked; the transmitter remains
461 * stuck off even if rx flow control is subsequently disabled
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +0200462 */
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +0200463
464 /*
465 * IXOFF Flag:
466 * Enable XON/XOFF flow control on output.
467 * Transmit XON1, XOFF1
468 */
Peter Hurley391f93f2015-01-25 14:44:51 -0500469 if (termios->c_iflag & IXOFF) {
470 up->port.status |= UPSTAT_AUTOXOFF;
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +0200471 priv->efr |= OMAP_UART_SW_TX;
Peter Hurley391f93f2015-01-25 14:44:51 -0500472 }
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +0200473 }
474 omap8250_restore_regs(up);
475
476 spin_unlock_irq(&up->port.lock);
477 pm_runtime_mark_last_busy(port->dev);
478 pm_runtime_put_autosuspend(port->dev);
479
480 /* calculate wakeup latency constraint */
481 priv->calc_latency = USEC_PER_SEC * 64 * 8 / baud;
482 priv->latency = priv->calc_latency;
483
484 schedule_work(&priv->qos_work);
485
486 /* Don't rewrite B0 */
487 if (tty_termios_baud_rate(termios))
488 tty_termios_encode_baud_rate(termios, baud, baud);
489}
490
491/* same as 8250 except that we may have extra flow bits set in EFR */
492static void omap_8250_pm(struct uart_port *port, unsigned int state,
493 unsigned int oldstate)
494{
Peter Hurley3e29af22014-12-31 16:32:49 -0500495 struct uart_8250_port *up = up_to_u8250p(port);
496 u8 efr;
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +0200497
498 pm_runtime_get_sync(port->dev);
499 serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
Peter Hurley3e29af22014-12-31 16:32:49 -0500500 efr = serial_in(up, UART_EFR);
501 serial_out(up, UART_EFR, efr | UART_EFR_ECB);
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +0200502 serial_out(up, UART_LCR, 0);
503
504 serial_out(up, UART_IER, (state != 0) ? UART_IERX_SLEEP : 0);
505 serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
Peter Hurley3e29af22014-12-31 16:32:49 -0500506 serial_out(up, UART_EFR, efr);
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +0200507 serial_out(up, UART_LCR, 0);
508
509 pm_runtime_mark_last_busy(port->dev);
510 pm_runtime_put_autosuspend(port->dev);
511}
512
513static void omap_serial_fill_features_erratas(struct uart_8250_port *up,
514 struct omap8250_priv *priv)
515{
516 u32 mvr, scheme;
517 u16 revision, major, minor;
518
519 mvr = uart_read(up, UART_OMAP_MVER);
520
521 /* Check revision register scheme */
522 scheme = mvr >> OMAP_UART_MVR_SCHEME_SHIFT;
523
524 switch (scheme) {
525 case 0: /* Legacy Scheme: OMAP2/3 */
526 /* MINOR_REV[0:4], MAJOR_REV[4:7] */
527 major = (mvr & OMAP_UART_LEGACY_MVR_MAJ_MASK) >>
528 OMAP_UART_LEGACY_MVR_MAJ_SHIFT;
529 minor = (mvr & OMAP_UART_LEGACY_MVR_MIN_MASK);
530 break;
531 case 1:
532 /* New Scheme: OMAP4+ */
533 /* MINOR_REV[0:5], MAJOR_REV[8:10] */
534 major = (mvr & OMAP_UART_MVR_MAJ_MASK) >>
535 OMAP_UART_MVR_MAJ_SHIFT;
536 minor = (mvr & OMAP_UART_MVR_MIN_MASK);
537 break;
538 default:
539 dev_warn(up->port.dev,
540 "Unknown revision, defaulting to highest\n");
541 /* highest possible revision */
542 major = 0xff;
543 minor = 0xff;
544 }
545 /* normalize revision for the driver */
546 revision = UART_BUILD_REVISION(major, minor);
547
548 switch (revision) {
549 case OMAP_UART_REV_46:
Sekhar Nori4fcdff92015-07-14 13:32:06 +0530550 priv->habit |= UART_ERRATA_i202_MDR1_ACCESS;
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +0200551 break;
552 case OMAP_UART_REV_52:
Sekhar Nori4fcdff92015-07-14 13:32:06 +0530553 priv->habit |= UART_ERRATA_i202_MDR1_ACCESS |
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +0200554 OMAP_UART_WER_HAS_TX_WAKEUP;
555 break;
556 case OMAP_UART_REV_63:
Sekhar Nori4fcdff92015-07-14 13:32:06 +0530557 priv->habit |= UART_ERRATA_i202_MDR1_ACCESS |
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +0200558 OMAP_UART_WER_HAS_TX_WAKEUP;
559 break;
560 default:
561 break;
562 }
563}
564
565static void omap8250_uart_qos_work(struct work_struct *work)
566{
567 struct omap8250_priv *priv;
568
569 priv = container_of(work, struct omap8250_priv, qos_work);
570 pm_qos_update_request(&priv->pm_qos_request, priv->latency);
571}
572
Sebastian Andrzej Siewior9e915972015-05-20 22:07:35 +0200573#ifdef CONFIG_SERIAL_8250_DMA
574static int omap_8250_dma_handle_irq(struct uart_port *port);
575#endif
576
577static irqreturn_t omap8250_irq(int irq, void *dev_id)
578{
579 struct uart_port *port = dev_id;
580 struct uart_8250_port *up = up_to_u8250p(port);
581 unsigned int iir;
582 int ret;
583
584#ifdef CONFIG_SERIAL_8250_DMA
585 if (up->dma) {
586 ret = omap_8250_dma_handle_irq(port);
587 return IRQ_RETVAL(ret);
588 }
589#endif
590
591 serial8250_rpm_get(up);
592 iir = serial_port_in(port, UART_IIR);
593 ret = serial8250_handle_irq(port, iir);
594 serial8250_rpm_put(up);
595
596 return IRQ_RETVAL(ret);
597}
598
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +0200599static int omap_8250_startup(struct uart_port *port)
600{
Sebastian Andrzej Siewior9e915972015-05-20 22:07:35 +0200601 struct uart_8250_port *up = up_to_u8250p(port);
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +0200602 struct omap8250_priv *priv = port->private_data;
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +0200603 int ret;
604
605 if (priv->wakeirq) {
Tony Lindgrena3e362f2015-06-09 23:35:00 -0700606 ret = dev_pm_set_dedicated_wake_irq(port->dev, priv->wakeirq);
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +0200607 if (ret)
608 return ret;
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +0200609 }
610
611 pm_runtime_get_sync(port->dev);
612
Sebastian Andrzej Siewior9e915972015-05-20 22:07:35 +0200613 up->mcr = 0;
614 serial_out(up, UART_FCR, UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
615
616 serial_out(up, UART_LCR, UART_LCR_WLEN8);
617
618 up->lsr_saved_flags = 0;
619 up->msr_saved_flags = 0;
620
621 if (up->dma) {
622 ret = serial8250_request_dma(up);
623 if (ret) {
624 dev_warn_ratelimited(port->dev,
625 "failed to request DMA\n");
626 up->dma = NULL;
627 }
628 }
629
630 ret = request_irq(port->irq, omap8250_irq, IRQF_SHARED,
631 dev_name(port->dev), port);
632 if (ret < 0)
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +0200633 goto err;
634
Sebastian Andrzej Siewior9e915972015-05-20 22:07:35 +0200635 up->ier = UART_IER_RLSI | UART_IER_RDI;
636 serial_out(up, UART_IER, up->ier);
637
Rafael J. Wysocki71504e52014-12-19 15:27:58 +0100638#ifdef CONFIG_PM
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +0200639 up->capabilities |= UART_CAP_RPM;
640#endif
641
642 /* Enable module level wake up */
643 priv->wer = OMAP_UART_WER_MOD_WKUP;
644 if (priv->habit & OMAP_UART_WER_HAS_TX_WAKEUP)
645 priv->wer |= OMAP_UART_TX_WAKEUP_EN;
646 serial_out(up, UART_OMAP_WER, priv->wer);
647
Sebastian Andrzej Siewior0a0661d2014-09-29 20:06:49 +0200648 if (up->dma)
Peter Hurley33d9b8b22016-04-09 22:14:36 -0700649 up->dma->rx_dma(up);
Sebastian Andrzej Siewior0a0661d2014-09-29 20:06:49 +0200650
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +0200651 pm_runtime_mark_last_busy(port->dev);
652 pm_runtime_put_autosuspend(port->dev);
653 return 0;
654err:
655 pm_runtime_mark_last_busy(port->dev);
656 pm_runtime_put_autosuspend(port->dev);
Tony Lindgrena3e362f2015-06-09 23:35:00 -0700657 dev_pm_clear_wake_irq(port->dev);
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +0200658 return ret;
659}
660
661static void omap_8250_shutdown(struct uart_port *port)
662{
Sebastian Andrzej Siewior9e915972015-05-20 22:07:35 +0200663 struct uart_8250_port *up = up_to_u8250p(port);
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +0200664 struct omap8250_priv *priv = port->private_data;
665
666 flush_work(&priv->qos_work);
Sebastian Andrzej Siewior0a0661d2014-09-29 20:06:49 +0200667 if (up->dma)
Peter Hurley33d9b8b22016-04-09 22:14:36 -0700668 omap_8250_rx_dma_flush(up);
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +0200669
670 pm_runtime_get_sync(port->dev);
671
672 serial_out(up, UART_OMAP_WER, 0);
Sebastian Andrzej Siewior9e915972015-05-20 22:07:35 +0200673
674 up->ier = 0;
675 serial_out(up, UART_IER, 0);
676
677 if (up->dma)
678 serial8250_release_dma(up);
679
680 /*
681 * Disable break condition and FIFOs
682 */
683 if (up->lcr & UART_LCR_SBC)
684 serial_out(up, UART_LCR, up->lcr & ~UART_LCR_SBC);
685 serial_out(up, UART_FCR, UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +0200686
687 pm_runtime_mark_last_busy(port->dev);
688 pm_runtime_put_autosuspend(port->dev);
Sebastian Andrzej Siewior9e915972015-05-20 22:07:35 +0200689 free_irq(port->irq, port);
Tony Lindgrena3e362f2015-06-09 23:35:00 -0700690 dev_pm_clear_wake_irq(port->dev);
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +0200691}
692
693static void omap_8250_throttle(struct uart_port *port)
694{
Andy Shevchenko013e3582016-02-18 21:22:59 +0200695 struct uart_8250_port *up = up_to_u8250p(port);
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +0200696 unsigned long flags;
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +0200697
698 pm_runtime_get_sync(port->dev);
699
700 spin_lock_irqsave(&port->lock, flags);
701 up->ier &= ~(UART_IER_RLSI | UART_IER_RDI);
702 serial_out(up, UART_IER, up->ier);
703 spin_unlock_irqrestore(&port->lock, flags);
704
705 pm_runtime_mark_last_busy(port->dev);
706 pm_runtime_put_autosuspend(port->dev);
707}
708
Matwey V. Kornilov344cee22016-02-01 21:09:22 +0300709static int omap_8250_rs485_config(struct uart_port *port,
710 struct serial_rs485 *rs485)
711{
712 struct uart_8250_port *up = up_to_u8250p(port);
713
714 /* Clamp the delays to [0, 100ms] */
715 rs485->delay_rts_before_send = min(rs485->delay_rts_before_send, 100U);
716 rs485->delay_rts_after_send = min(rs485->delay_rts_after_send, 100U);
717
718 port->rs485 = *rs485;
719
720 /*
721 * Both serial8250_em485_init and serial8250_em485_destroy
722 * are idempotent
723 */
724 if (rs485->flags & SER_RS485_ENABLED) {
725 int ret = serial8250_em485_init(up);
726
727 if (ret) {
728 rs485->flags &= ~SER_RS485_ENABLED;
729 port->rs485.flags &= ~SER_RS485_ENABLED;
730 }
731 return ret;
732 }
733
734 serial8250_em485_destroy(up);
735
736 return 0;
737}
738
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +0200739static void omap_8250_unthrottle(struct uart_port *port)
740{
Andy Shevchenko013e3582016-02-18 21:22:59 +0200741 struct uart_8250_port *up = up_to_u8250p(port);
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +0200742 unsigned long flags;
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +0200743
744 pm_runtime_get_sync(port->dev);
745
746 spin_lock_irqsave(&port->lock, flags);
747 up->ier |= UART_IER_RLSI | UART_IER_RDI;
748 serial_out(up, UART_IER, up->ier);
749 spin_unlock_irqrestore(&port->lock, flags);
750
751 pm_runtime_mark_last_busy(port->dev);
752 pm_runtime_put_autosuspend(port->dev);
753}
754
Sebastian Andrzej Siewior31a17132014-09-29 20:06:43 +0200755#ifdef CONFIG_SERIAL_8250_DMA
Peter Hurley33d9b8b22016-04-09 22:14:36 -0700756static int omap_8250_rx_dma(struct uart_8250_port *p);
Sebastian Andrzej Siewior0e31c8d2014-09-29 20:06:44 +0200757
Peter Hurleyb74fdd22016-04-09 22:14:35 -0700758static void __dma_rx_do_complete(struct uart_8250_port *p)
Sebastian Andrzej Siewior0e31c8d2014-09-29 20:06:44 +0200759{
John Ognesseda0cd32015-04-27 13:52:33 +0200760 struct omap8250_priv *priv = p->port.private_data;
Sebastian Andrzej Siewior0e31c8d2014-09-29 20:06:44 +0200761 struct uart_8250_dma *dma = p->dma;
762 struct tty_port *tty_port = &p->port.state->port;
763 struct dma_tx_state state;
764 int count;
John Ognesseda0cd32015-04-27 13:52:33 +0200765 unsigned long flags;
Sebastian Andrzej Siewior658e2eb2015-08-14 18:01:03 +0200766 int ret;
Sebastian Andrzej Siewior0e31c8d2014-09-29 20:06:44 +0200767
John Ognesseda0cd32015-04-27 13:52:33 +0200768 spin_lock_irqsave(&priv->rx_dma_lock, flags);
769
770 if (!dma->rx_running)
771 goto unlock;
772
Sebastian Andrzej Siewior0e31c8d2014-09-29 20:06:44 +0200773 dma->rx_running = 0;
774 dmaengine_tx_status(dma->rxchan, dma->rx_cookie, &state);
Sebastian Andrzej Siewior0e31c8d2014-09-29 20:06:44 +0200775
776 count = dma->rx_size - state.residue;
777
Sebastian Andrzej Siewior658e2eb2015-08-14 18:01:03 +0200778 ret = tty_insert_flip_string(tty_port, dma->rx_buf, count);
779
780 p->port.icount.rx += ret;
781 p->port.icount.buf_overrun += count - ret;
John Ognesseda0cd32015-04-27 13:52:33 +0200782unlock:
783 spin_unlock_irqrestore(&priv->rx_dma_lock, flags);
784
Sebastian Andrzej Siewior0e31c8d2014-09-29 20:06:44 +0200785 tty_flip_buffer_push(tty_port);
786}
787
788static void __dma_rx_complete(void *param)
789{
Peter Hurleyb74fdd22016-04-09 22:14:35 -0700790 __dma_rx_do_complete(param);
Peter Hurley33d9b8b22016-04-09 22:14:36 -0700791 omap_8250_rx_dma(param);
Sebastian Andrzej Siewior0e31c8d2014-09-29 20:06:44 +0200792}
793
John Ognesseda0cd32015-04-27 13:52:33 +0200794static void omap_8250_rx_dma_flush(struct uart_8250_port *p)
795{
796 struct omap8250_priv *priv = p->port.private_data;
797 struct uart_8250_dma *dma = p->dma;
798 unsigned long flags;
Sebastian Andrzej Siewior830acf92015-08-14 17:52:07 +0200799 int ret;
John Ognesseda0cd32015-04-27 13:52:33 +0200800
801 spin_lock_irqsave(&priv->rx_dma_lock, flags);
802
803 if (!dma->rx_running) {
804 spin_unlock_irqrestore(&priv->rx_dma_lock, flags);
805 return;
806 }
807
Sebastian Andrzej Siewior830acf92015-08-14 17:52:07 +0200808 ret = dmaengine_pause(dma->rxchan);
809 if (WARN_ON_ONCE(ret))
810 priv->rx_dma_broken = true;
John Ognesseda0cd32015-04-27 13:52:33 +0200811
812 spin_unlock_irqrestore(&priv->rx_dma_lock, flags);
813
Peter Hurleyb74fdd22016-04-09 22:14:35 -0700814 __dma_rx_do_complete(p);
Peter Hurleyd1f98152016-04-09 22:14:37 -0700815 dmaengine_terminate_all(dma->rxchan);
John Ognesseda0cd32015-04-27 13:52:33 +0200816}
817
Peter Hurley33d9b8b22016-04-09 22:14:36 -0700818static int omap_8250_rx_dma(struct uart_8250_port *p)
Sebastian Andrzej Siewior0e31c8d2014-09-29 20:06:44 +0200819{
John Ognesseda0cd32015-04-27 13:52:33 +0200820 struct omap8250_priv *priv = p->port.private_data;
Sebastian Andrzej Siewior0e31c8d2014-09-29 20:06:44 +0200821 struct uart_8250_dma *dma = p->dma;
John Ognesseda0cd32015-04-27 13:52:33 +0200822 int err = 0;
Sebastian Andrzej Siewior0e31c8d2014-09-29 20:06:44 +0200823 struct dma_async_tx_descriptor *desc;
John Ognesseda0cd32015-04-27 13:52:33 +0200824 unsigned long flags;
Sebastian Andrzej Siewior0e31c8d2014-09-29 20:06:44 +0200825
Sebastian Andrzej Siewior830acf92015-08-14 17:52:07 +0200826 if (priv->rx_dma_broken)
827 return -EINVAL;
828
John Ognesseda0cd32015-04-27 13:52:33 +0200829 spin_lock_irqsave(&priv->rx_dma_lock, flags);
830
Sebastian Andrzej Siewior0e31c8d2014-09-29 20:06:44 +0200831 if (dma->rx_running)
John Ognesseda0cd32015-04-27 13:52:33 +0200832 goto out;
Sebastian Andrzej Siewior0e31c8d2014-09-29 20:06:44 +0200833
834 desc = dmaengine_prep_slave_single(dma->rxchan, dma->rx_addr,
835 dma->rx_size, DMA_DEV_TO_MEM,
836 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
John Ognesseda0cd32015-04-27 13:52:33 +0200837 if (!desc) {
838 err = -EBUSY;
839 goto out;
840 }
Sebastian Andrzej Siewior0e31c8d2014-09-29 20:06:44 +0200841
842 dma->rx_running = 1;
843 desc->callback = __dma_rx_complete;
844 desc->callback_param = p;
845
846 dma->rx_cookie = dmaengine_submit(desc);
847
Sebastian Andrzej Siewior0e31c8d2014-09-29 20:06:44 +0200848 dma_async_issue_pending(dma->rxchan);
John Ognesseda0cd32015-04-27 13:52:33 +0200849out:
850 spin_unlock_irqrestore(&priv->rx_dma_lock, flags);
851 return err;
Sebastian Andrzej Siewior0e31c8d2014-09-29 20:06:44 +0200852}
853
Sebastian Andrzej Siewior31a17132014-09-29 20:06:43 +0200854static int omap_8250_tx_dma(struct uart_8250_port *p);
855
856static void omap_8250_dma_tx_complete(void *param)
857{
858 struct uart_8250_port *p = param;
859 struct uart_8250_dma *dma = p->dma;
860 struct circ_buf *xmit = &p->port.state->xmit;
861 unsigned long flags;
862 bool en_thri = false;
Sebastian Andrzej Siewior0a0661d2014-09-29 20:06:49 +0200863 struct omap8250_priv *priv = p->port.private_data;
Sebastian Andrzej Siewior31a17132014-09-29 20:06:43 +0200864
865 dma_sync_single_for_cpu(dma->txchan->device->dev, dma->tx_addr,
866 UART_XMIT_SIZE, DMA_TO_DEVICE);
867
868 spin_lock_irqsave(&p->port.lock, flags);
869
870 dma->tx_running = 0;
871
872 xmit->tail += dma->tx_size;
873 xmit->tail &= UART_XMIT_SIZE - 1;
874 p->port.icount.tx += dma->tx_size;
875
Sebastian Andrzej Siewior0a0661d2014-09-29 20:06:49 +0200876 if (priv->delayed_restore) {
877 priv->delayed_restore = 0;
878 omap8250_restore_regs(p);
879 }
880
Sebastian Andrzej Siewior31a17132014-09-29 20:06:43 +0200881 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
882 uart_write_wakeup(&p->port);
883
884 if (!uart_circ_empty(xmit) && !uart_tx_stopped(&p->port)) {
885 int ret;
886
887 ret = omap_8250_tx_dma(p);
888 if (ret)
889 en_thri = true;
890
891 } else if (p->capabilities & UART_CAP_RPM) {
892 en_thri = true;
893 }
894
895 if (en_thri) {
896 dma->tx_err = 1;
897 p->ier |= UART_IER_THRI;
898 serial_port_out(&p->port, UART_IER, p->ier);
899 }
900
901 spin_unlock_irqrestore(&p->port.lock, flags);
902}
903
904static int omap_8250_tx_dma(struct uart_8250_port *p)
905{
906 struct uart_8250_dma *dma = p->dma;
907 struct omap8250_priv *priv = p->port.private_data;
908 struct circ_buf *xmit = &p->port.state->xmit;
909 struct dma_async_tx_descriptor *desc;
910 unsigned int skip_byte = 0;
911 int ret;
912
913 if (dma->tx_running)
914 return 0;
915 if (uart_tx_stopped(&p->port) || uart_circ_empty(xmit)) {
916
917 /*
918 * Even if no data, we need to return an error for the two cases
919 * below so serial8250_tx_chars() is invoked and properly clears
920 * THRI and/or runtime suspend.
921 */
922 if (dma->tx_err || p->capabilities & UART_CAP_RPM) {
923 ret = -EBUSY;
924 goto err;
925 }
926 if (p->ier & UART_IER_THRI) {
927 p->ier &= ~UART_IER_THRI;
928 serial_out(p, UART_IER, p->ier);
929 }
930 return 0;
931 }
932
933 dma->tx_size = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
934 if (priv->habit & OMAP_DMA_TX_KICK) {
935 u8 tx_lvl;
936
937 /*
938 * We need to put the first byte into the FIFO in order to start
939 * the DMA transfer. For transfers smaller than four bytes we
940 * don't bother doing DMA at all. It seem not matter if there
941 * are still bytes in the FIFO from the last transfer (in case
942 * we got here directly from omap_8250_dma_tx_complete()). Bytes
943 * leaving the FIFO seem not to trigger the DMA transfer. It is
944 * really the byte that we put into the FIFO.
945 * If the FIFO is already full then we most likely got here from
946 * omap_8250_dma_tx_complete(). And this means the DMA engine
947 * just completed its work. We don't have to wait the complete
948 * 86us at 115200,8n1 but around 60us (not to mention lower
949 * baudrates). So in that case we take the interrupt and try
950 * again with an empty FIFO.
951 */
952 tx_lvl = serial_in(p, UART_OMAP_TX_LVL);
953 if (tx_lvl == p->tx_loadsz) {
954 ret = -EBUSY;
955 goto err;
956 }
957 if (dma->tx_size < 4) {
958 ret = -EINVAL;
959 goto err;
960 }
961 skip_byte = 1;
962 }
963
964 desc = dmaengine_prep_slave_single(dma->txchan,
965 dma->tx_addr + xmit->tail + skip_byte,
966 dma->tx_size - skip_byte, DMA_MEM_TO_DEV,
967 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
968 if (!desc) {
969 ret = -EBUSY;
970 goto err;
971 }
972
973 dma->tx_running = 1;
974
975 desc->callback = omap_8250_dma_tx_complete;
976 desc->callback_param = p;
977
978 dma->tx_cookie = dmaengine_submit(desc);
979
980 dma_sync_single_for_device(dma->txchan->device->dev, dma->tx_addr,
981 UART_XMIT_SIZE, DMA_TO_DEVICE);
982
983 dma_async_issue_pending(dma->txchan);
984 if (dma->tx_err)
985 dma->tx_err = 0;
986
987 if (p->ier & UART_IER_THRI) {
988 p->ier &= ~UART_IER_THRI;
989 serial_out(p, UART_IER, p->ier);
990 }
991 if (skip_byte)
992 serial_out(p, UART_TX, xmit->buf[xmit->tail]);
993 return 0;
994err:
995 dma->tx_err = 1;
996 return ret;
997}
998
Peter Hurley33d9b8b22016-04-09 22:14:36 -0700999static bool handle_rx_dma(struct uart_8250_port *up, unsigned int iir)
1000{
1001 switch (iir & 0x3f) {
1002 case UART_IIR_RLSI:
1003 case UART_IIR_RX_TIMEOUT:
1004 case UART_IIR_RDI:
1005 omap_8250_rx_dma_flush(up);
1006 return true;
1007 }
1008 return omap_8250_rx_dma(up);
1009}
1010
Sebastian Andrzej Siewior77285242014-09-29 20:06:48 +02001011/*
1012 * This is mostly serial8250_handle_irq(). We have a slightly different DMA
1013 * hoook for RX/TX and need different logic for them in the ISR. Therefore we
1014 * use the default routine in the non-DMA case and this one for with DMA.
1015 */
1016static int omap_8250_dma_handle_irq(struct uart_port *port)
1017{
1018 struct uart_8250_port *up = up_to_u8250p(port);
1019 unsigned char status;
1020 unsigned long flags;
1021 u8 iir;
Sebastian Andrzej Siewior77285242014-09-29 20:06:48 +02001022
1023 serial8250_rpm_get(up);
1024
1025 iir = serial_port_in(port, UART_IIR);
1026 if (iir & UART_IIR_NO_INT) {
1027 serial8250_rpm_put(up);
1028 return 0;
1029 }
1030
1031 spin_lock_irqsave(&port->lock, flags);
1032
1033 status = serial_port_in(port, UART_LSR);
1034
1035 if (status & (UART_LSR_DR | UART_LSR_BI)) {
Peter Hurley33d9b8b22016-04-09 22:14:36 -07001036 if (handle_rx_dma(up, iir)) {
Sebastian Andrzej Siewior77285242014-09-29 20:06:48 +02001037 status = serial8250_rx_chars(up, status);
Peter Hurley33d9b8b22016-04-09 22:14:36 -07001038 omap_8250_rx_dma(up);
Sebastian Andrzej Siewior77285242014-09-29 20:06:48 +02001039 }
1040 }
1041 serial8250_modem_status(up);
1042 if (status & UART_LSR_THRE && up->dma->tx_err) {
1043 if (uart_tx_stopped(&up->port) ||
1044 uart_circ_empty(&up->port.state->xmit)) {
1045 up->dma->tx_err = 0;
1046 serial8250_tx_chars(up);
1047 } else {
1048 /*
1049 * try again due to an earlier failer which
1050 * might have been resolved by now.
1051 */
Peter Hurleya86f50e2016-04-09 20:49:41 -07001052 if (omap_8250_tx_dma(up))
Sebastian Andrzej Siewior77285242014-09-29 20:06:48 +02001053 serial8250_tx_chars(up);
1054 }
1055 }
1056
1057 spin_unlock_irqrestore(&port->lock, flags);
1058 serial8250_rpm_put(up);
1059 return 1;
1060}
Sebastian Andrzej Siewior0a0661d2014-09-29 20:06:49 +02001061
1062static bool the_no_dma_filter_fn(struct dma_chan *chan, void *param)
1063{
1064 return false;
1065}
1066
1067#else
1068
Peter Hurley33d9b8b22016-04-09 22:14:36 -07001069static inline int omap_8250_rx_dma(struct uart_8250_port *p)
Sebastian Andrzej Siewior0a0661d2014-09-29 20:06:49 +02001070{
1071 return -EINVAL;
1072}
Sebastian Andrzej Siewior31a17132014-09-29 20:06:43 +02001073#endif
1074
Sebastian Andrzej Siewior9e915972015-05-20 22:07:35 +02001075static int omap8250_no_handle_irq(struct uart_port *port)
1076{
1077 /* IRQ has not been requested but handling irq? */
1078 WARN_ONCE(1, "Unexpected irq handling before port startup\n");
1079 return 0;
1080}
1081
Sekhar Noricdb929e2015-07-14 13:32:07 +05301082static const u8 am3352_habit = OMAP_DMA_TX_KICK | UART_ERRATA_CLOCK_DISABLE;
1083static const u8 am4372_habit = UART_ERRATA_CLOCK_DISABLE;
Sekhar Nori4fcdff92015-07-14 13:32:06 +05301084
1085static const struct of_device_id omap8250_dt_ids[] = {
1086 { .compatible = "ti,omap2-uart" },
1087 { .compatible = "ti,omap3-uart" },
1088 { .compatible = "ti,omap4-uart" },
1089 { .compatible = "ti,am3352-uart", .data = &am3352_habit, },
Sekhar Noricdb929e2015-07-14 13:32:07 +05301090 { .compatible = "ti,am4372-uart", .data = &am4372_habit, },
Sekhar Nori27c93af2015-07-14 13:32:08 +05301091 { .compatible = "ti,dra742-uart", .data = &am4372_habit, },
Sekhar Nori4fcdff92015-07-14 13:32:06 +05301092 {},
1093};
1094MODULE_DEVICE_TABLE(of, omap8250_dt_ids);
1095
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +02001096static int omap8250_probe(struct platform_device *pdev)
1097{
1098 struct resource *regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1099 struct resource *irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
1100 struct omap8250_priv *priv;
1101 struct uart_8250_port up;
1102 int ret;
1103 void __iomem *membase;
1104
1105 if (!regs || !irq) {
1106 dev_err(&pdev->dev, "missing registers or irq\n");
1107 return -EINVAL;
1108 }
1109
1110 priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
1111 if (!priv)
1112 return -ENOMEM;
1113
1114 membase = devm_ioremap_nocache(&pdev->dev, regs->start,
1115 resource_size(regs));
1116 if (!membase)
1117 return -ENODEV;
1118
1119 memset(&up, 0, sizeof(up));
1120 up.port.dev = &pdev->dev;
1121 up.port.mapbase = regs->start;
1122 up.port.membase = membase;
1123 up.port.irq = irq->start;
1124 /*
1125 * It claims to be 16C750 compatible however it is a little different.
1126 * It has EFR and has no FCR7_64byte bit. The AFE (which it claims to
1127 * have) is enabled via EFR instead of MCR. The type is set here 8250
1128 * just to get things going. UNKNOWN does not work for a few reasons and
1129 * we don't need our own type since we don't use 8250's set_termios()
1130 * or pm callback.
1131 */
1132 up.port.type = PORT_8250;
1133 up.port.iotype = UPIO_MEM;
1134 up.port.flags = UPF_FIXED_PORT | UPF_FIXED_TYPE | UPF_SOFT_FLOW |
1135 UPF_HARD_FLOW;
1136 up.port.private_data = priv;
1137
1138 up.port.regshift = 2;
1139 up.port.fifosize = 64;
1140 up.tx_loadsz = 64;
1141 up.capabilities = UART_CAP_FIFO;
Rafael J. Wysocki71504e52014-12-19 15:27:58 +01001142#ifdef CONFIG_PM
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +02001143 /*
Rafael J. Wysocki71504e52014-12-19 15:27:58 +01001144 * Runtime PM is mostly transparent. However to do it right we need to a
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +02001145 * TX empty interrupt before we can put the device to auto idle. So if
Rafael J. Wysocki71504e52014-12-19 15:27:58 +01001146 * PM is not enabled we don't add that flag and can spare that one extra
1147 * interrupt in the TX path.
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +02001148 */
1149 up.capabilities |= UART_CAP_RPM;
1150#endif
1151 up.port.set_termios = omap_8250_set_termios;
Peter Hurley4bf4ea92014-12-30 20:28:15 -05001152 up.port.set_mctrl = omap8250_set_mctrl;
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +02001153 up.port.pm = omap_8250_pm;
1154 up.port.startup = omap_8250_startup;
1155 up.port.shutdown = omap_8250_shutdown;
1156 up.port.throttle = omap_8250_throttle;
1157 up.port.unthrottle = omap_8250_unthrottle;
Matwey V. Kornilov344cee22016-02-01 21:09:22 +03001158 up.port.rs485_config = omap_8250_rs485_config;
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +02001159
1160 if (pdev->dev.of_node) {
Sekhar Nori4fcdff92015-07-14 13:32:06 +05301161 const struct of_device_id *id;
1162
Sebastian Andrzej Siewior54178fe2014-11-12 10:28:33 +01001163 ret = of_alias_get_id(pdev->dev.of_node, "serial");
1164
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +02001165 of_property_read_u32(pdev->dev.of_node, "clock-frequency",
1166 &up.port.uartclk);
1167 priv->wakeirq = irq_of_parse_and_map(pdev->dev.of_node, 1);
Sekhar Nori4fcdff92015-07-14 13:32:06 +05301168
1169 id = of_match_device(of_match_ptr(omap8250_dt_ids), &pdev->dev);
1170 if (id && id->data)
1171 priv->habit |= *(u8 *)id->data;
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +02001172 } else {
Sebastian Andrzej Siewior54178fe2014-11-12 10:28:33 +01001173 ret = pdev->id;
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +02001174 }
Sebastian Andrzej Siewior54178fe2014-11-12 10:28:33 +01001175 if (ret < 0) {
1176 dev_err(&pdev->dev, "failed to get alias/pdev id\n");
1177 return ret;
1178 }
1179 up.port.line = ret;
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +02001180
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +02001181 if (!up.port.uartclk) {
1182 up.port.uartclk = DEFAULT_CLK_SPEED;
1183 dev_warn(&pdev->dev,
1184 "No clock speed specified: using default: %d\n",
1185 DEFAULT_CLK_SPEED);
1186 }
1187
1188 priv->latency = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE;
1189 priv->calc_latency = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE;
1190 pm_qos_add_request(&priv->pm_qos_request, PM_QOS_CPU_DMA_LATENCY,
1191 priv->latency);
1192 INIT_WORK(&priv->qos_work, omap8250_uart_qos_work);
1193
John Ognesseda0cd32015-04-27 13:52:33 +02001194 spin_lock_init(&priv->rx_dma_lock);
1195
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +02001196 device_init_wakeup(&pdev->dev, true);
1197 pm_runtime_use_autosuspend(&pdev->dev);
1198 pm_runtime_set_autosuspend_delay(&pdev->dev, -1);
1199
1200 pm_runtime_irq_safe(&pdev->dev);
1201 pm_runtime_enable(&pdev->dev);
1202
1203 pm_runtime_get_sync(&pdev->dev);
1204
1205 omap_serial_fill_features_erratas(&up, priv);
Sebastian Andrzej Siewior9e915972015-05-20 22:07:35 +02001206 up.port.handle_irq = omap8250_no_handle_irq;
Sebastian Andrzej Siewior0a0661d2014-09-29 20:06:49 +02001207#ifdef CONFIG_SERIAL_8250_DMA
1208 if (pdev->dev.of_node) {
1209 /*
1210 * Oh DMA support. If there are no DMA properties in the DT then
1211 * we will fall back to a generic DMA channel which does not
1212 * really work here. To ensure that we do not get a generic DMA
1213 * channel assigned, we have the the_no_dma_filter_fn() here.
1214 * To avoid "failed to request DMA" messages we check for DMA
1215 * properties in DT.
1216 */
1217 ret = of_property_count_strings(pdev->dev.of_node, "dma-names");
1218 if (ret == 2) {
1219 up.dma = &priv->omap8250_dma;
Sebastian Andrzej Siewior0a0661d2014-09-29 20:06:49 +02001220 priv->omap8250_dma.fn = the_no_dma_filter_fn;
1221 priv->omap8250_dma.tx_dma = omap_8250_tx_dma;
1222 priv->omap8250_dma.rx_dma = omap_8250_rx_dma;
1223 priv->omap8250_dma.rx_size = RX_TRIGGER;
1224 priv->omap8250_dma.rxconf.src_maxburst = RX_TRIGGER;
1225 priv->omap8250_dma.txconf.dst_maxburst = TX_TRIGGER;
1226
1227 if (of_machine_is_compatible("ti,am33xx"))
1228 priv->habit |= OMAP_DMA_TX_KICK;
Sebastian Andrzej Siewior830acf92015-08-14 17:52:07 +02001229 /*
1230 * pause is currently not supported atleast on omap-sdma
1231 * and edma on most earlier kernels.
1232 */
1233 priv->rx_dma_broken = true;
Sebastian Andrzej Siewior0a0661d2014-09-29 20:06:49 +02001234 }
1235 }
1236#endif
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +02001237 ret = serial8250_register_8250_port(&up);
1238 if (ret < 0) {
1239 dev_err(&pdev->dev, "unable to register 8250 port\n");
1240 goto err;
1241 }
1242 priv->line = ret;
1243 platform_set_drvdata(pdev, priv);
1244 pm_runtime_mark_last_busy(&pdev->dev);
1245 pm_runtime_put_autosuspend(&pdev->dev);
1246 return 0;
1247err:
1248 pm_runtime_put(&pdev->dev);
1249 pm_runtime_disable(&pdev->dev);
1250 return ret;
1251}
1252
1253static int omap8250_remove(struct platform_device *pdev)
1254{
1255 struct omap8250_priv *priv = platform_get_drvdata(pdev);
1256
1257 pm_runtime_put_sync(&pdev->dev);
1258 pm_runtime_disable(&pdev->dev);
1259 serial8250_unregister_port(priv->line);
1260 pm_qos_remove_request(&priv->pm_qos_request);
1261 device_init_wakeup(&pdev->dev, false);
1262 return 0;
1263}
1264
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +02001265#ifdef CONFIG_PM_SLEEP
1266static int omap8250_prepare(struct device *dev)
1267{
1268 struct omap8250_priv *priv = dev_get_drvdata(dev);
1269
1270 if (!priv)
1271 return 0;
1272 priv->is_suspending = true;
1273 return 0;
1274}
1275
1276static void omap8250_complete(struct device *dev)
1277{
1278 struct omap8250_priv *priv = dev_get_drvdata(dev);
1279
1280 if (!priv)
1281 return;
1282 priv->is_suspending = false;
1283}
1284
1285static int omap8250_suspend(struct device *dev)
1286{
1287 struct omap8250_priv *priv = dev_get_drvdata(dev);
1288
1289 serial8250_suspend_port(priv->line);
1290 flush_work(&priv->qos_work);
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +02001291 return 0;
1292}
1293
1294static int omap8250_resume(struct device *dev)
1295{
1296 struct omap8250_priv *priv = dev_get_drvdata(dev);
1297
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +02001298 serial8250_resume_port(priv->line);
1299 return 0;
1300}
1301#else
1302#define omap8250_prepare NULL
1303#define omap8250_complete NULL
1304#endif
1305
Rafael J. Wysocki71504e52014-12-19 15:27:58 +01001306#ifdef CONFIG_PM
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +02001307static int omap8250_lost_context(struct uart_8250_port *up)
1308{
1309 u32 val;
1310
Sekhar Noricdb929e2015-07-14 13:32:07 +05301311 val = serial_in(up, UART_OMAP_SCR);
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +02001312 /*
Sekhar Noricdb929e2015-07-14 13:32:07 +05301313 * If we lose context, then SCR is set to its reset value of zero.
1314 * After set_termios() we set bit 3 of SCR (TX_EMPTY_CTL_IT) to 1,
1315 * among other bits, to never set the register back to zero again.
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +02001316 */
Sekhar Noricdb929e2015-07-14 13:32:07 +05301317 if (!val)
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +02001318 return 1;
1319 return 0;
1320}
1321
Sekhar Noricdb929e2015-07-14 13:32:07 +05301322/* TODO: in future, this should happen via API in drivers/reset/ */
1323static int omap8250_soft_reset(struct device *dev)
1324{
1325 struct omap8250_priv *priv = dev_get_drvdata(dev);
1326 struct uart_8250_port *up = serial8250_get_port(priv->line);
1327 int timeout = 100;
1328 int sysc;
1329 int syss;
1330
1331 sysc = serial_in(up, UART_OMAP_SYSC);
1332
1333 /* softreset the UART */
1334 sysc |= OMAP_UART_SYSC_SOFTRESET;
1335 serial_out(up, UART_OMAP_SYSC, sysc);
1336
1337 /* By experiments, 1us enough for reset complete on AM335x */
1338 do {
1339 udelay(1);
1340 syss = serial_in(up, UART_OMAP_SYSS);
1341 } while (--timeout && !(syss & OMAP_UART_SYSS_RESETDONE));
1342
1343 if (!timeout) {
1344 dev_err(dev, "timed out waiting for reset done\n");
1345 return -ETIMEDOUT;
1346 }
1347
1348 return 0;
1349}
1350
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +02001351static int omap8250_runtime_suspend(struct device *dev)
1352{
1353 struct omap8250_priv *priv = dev_get_drvdata(dev);
1354 struct uart_8250_port *up;
1355
1356 up = serial8250_get_port(priv->line);
1357 /*
1358 * When using 'no_console_suspend', the console UART must not be
1359 * suspended. Since driver suspend is managed by runtime suspend,
1360 * preventing runtime suspend (by returning error) will keep device
1361 * active during suspend.
1362 */
1363 if (priv->is_suspending && !console_suspend_enabled) {
1364 if (uart_console(&up->port))
1365 return -EBUSY;
1366 }
1367
Sekhar Noricdb929e2015-07-14 13:32:07 +05301368 if (priv->habit & UART_ERRATA_CLOCK_DISABLE) {
1369 int ret;
1370
1371 ret = omap8250_soft_reset(dev);
1372 if (ret)
1373 return ret;
1374
1375 /* Restore to UART mode after reset (for wakeup) */
1376 omap8250_update_mdr1(up, priv);
1377 }
1378
Sekhar Nori727fd8a2015-07-14 13:32:03 +05301379 if (up->dma && up->dma->rxchan)
Peter Hurley33d9b8b22016-04-09 22:14:36 -07001380 omap_8250_rx_dma_flush(up);
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +02001381
1382 priv->latency = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE;
1383 schedule_work(&priv->qos_work);
1384
1385 return 0;
1386}
1387
1388static int omap8250_runtime_resume(struct device *dev)
1389{
1390 struct omap8250_priv *priv = dev_get_drvdata(dev);
1391 struct uart_8250_port *up;
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +02001392
1393 /* In case runtime-pm tries this before we are setup */
1394 if (!priv)
1395 return 0;
1396
1397 up = serial8250_get_port(priv->line);
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +02001398
Peter Hurleyf56f0a52016-04-09 20:49:43 -07001399 if (omap8250_lost_context(up))
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +02001400 omap8250_restore_regs(up);
1401
Sekhar Nori727fd8a2015-07-14 13:32:03 +05301402 if (up->dma && up->dma->rxchan)
Peter Hurley33d9b8b22016-04-09 22:14:36 -07001403 omap_8250_rx_dma(up);
Sebastian Andrzej Siewior0a0661d2014-09-29 20:06:49 +02001404
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +02001405 priv->latency = priv->calc_latency;
1406 schedule_work(&priv->qos_work);
1407 return 0;
1408}
1409#endif
1410
Sebastian Andrzej Siewior00648d02014-12-18 18:47:12 +01001411#ifdef CONFIG_SERIAL_8250_OMAP_TTYO_FIXUP
1412static int __init omap8250_console_fixup(void)
1413{
1414 char *omap_str;
1415 char *options;
1416 u8 idx;
1417
1418 if (strstr(boot_command_line, "console=ttyS"))
1419 /* user set a ttyS based name for the console */
1420 return 0;
1421
1422 omap_str = strstr(boot_command_line, "console=ttyO");
1423 if (!omap_str)
1424 /* user did not set ttyO based console, so we don't care */
1425 return 0;
1426
1427 omap_str += 12;
1428 if ('0' <= *omap_str && *omap_str <= '9')
1429 idx = *omap_str - '0';
1430 else
1431 return 0;
1432
1433 omap_str++;
1434 if (omap_str[0] == ',') {
1435 omap_str++;
1436 options = omap_str;
1437 } else {
1438 options = NULL;
1439 }
1440
1441 add_preferred_console("ttyS", idx, options);
1442 pr_err("WARNING: Your 'console=ttyO%d' has been replaced by 'ttyS%d'\n",
1443 idx, idx);
1444 pr_err("This ensures that you still see kernel messages. Please\n");
1445 pr_err("update your kernel commandline.\n");
1446 return 0;
1447}
1448console_initcall(omap8250_console_fixup);
1449#endif
1450
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +02001451static const struct dev_pm_ops omap8250_dev_pm_ops = {
1452 SET_SYSTEM_SLEEP_PM_OPS(omap8250_suspend, omap8250_resume)
1453 SET_RUNTIME_PM_OPS(omap8250_runtime_suspend,
1454 omap8250_runtime_resume, NULL)
1455 .prepare = omap8250_prepare,
1456 .complete = omap8250_complete,
1457};
1458
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +02001459static struct platform_driver omap8250_platform_driver = {
1460 .driver = {
1461 .name = "omap8250",
1462 .pm = &omap8250_dev_pm_ops,
1463 .of_match_table = omap8250_dt_ids,
Sebastian Andrzej Siewior61929cf2014-09-29 20:06:39 +02001464 },
1465 .probe = omap8250_probe,
1466 .remove = omap8250_remove,
1467};
1468module_platform_driver(omap8250_platform_driver);
1469
1470MODULE_AUTHOR("Sebastian Andrzej Siewior");
1471MODULE_DESCRIPTION("OMAP 8250 Driver");
1472MODULE_LICENSE("GPL v2");