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1// SPDX-License-Identifier: GPL-2.0
2// Copyright (c) 2017-2018, The Linux foundation. All rights reserved.
3
4#include <linux/clk.h>
5#include <linux/console.h>
6#include <linux/io.h>
7#include <linux/iopoll.h>
8#include <linux/module.h>
9#include <linux/of.h>
10#include <linux/of_device.h>
11#include <linux/platform_device.h>
12#include <linux/qcom-geni-se.h>
13#include <linux/serial.h>
14#include <linux/serial_core.h>
15#include <linux/slab.h>
16#include <linux/tty.h>
17#include <linux/tty_flip.h>
18
19/* UART specific GENI registers */
20#define SE_UART_TX_TRANS_CFG 0x25c
21#define SE_UART_TX_WORD_LEN 0x268
22#define SE_UART_TX_STOP_BIT_LEN 0x26c
23#define SE_UART_TX_TRANS_LEN 0x270
24#define SE_UART_RX_TRANS_CFG 0x280
25#define SE_UART_RX_WORD_LEN 0x28c
26#define SE_UART_RX_STALE_CNT 0x294
27#define SE_UART_TX_PARITY_CFG 0x2a4
28#define SE_UART_RX_PARITY_CFG 0x2a8
29
30/* SE_UART_TRANS_CFG */
31#define UART_TX_PAR_EN BIT(0)
32#define UART_CTS_MASK BIT(1)
33
34/* SE_UART_TX_WORD_LEN */
35#define TX_WORD_LEN_MSK GENMASK(9, 0)
36
37/* SE_UART_TX_STOP_BIT_LEN */
38#define TX_STOP_BIT_LEN_MSK GENMASK(23, 0)
39#define TX_STOP_BIT_LEN_1 0
40#define TX_STOP_BIT_LEN_1_5 1
41#define TX_STOP_BIT_LEN_2 2
42
43/* SE_UART_TX_TRANS_LEN */
44#define TX_TRANS_LEN_MSK GENMASK(23, 0)
45
46/* SE_UART_RX_TRANS_CFG */
47#define UART_RX_INS_STATUS_BIT BIT(2)
48#define UART_RX_PAR_EN BIT(3)
49
50/* SE_UART_RX_WORD_LEN */
51#define RX_WORD_LEN_MASK GENMASK(9, 0)
52
53/* SE_UART_RX_STALE_CNT */
54#define RX_STALE_CNT GENMASK(23, 0)
55
56/* SE_UART_TX_PARITY_CFG/RX_PARITY_CFG */
57#define PAR_CALC_EN BIT(0)
58#define PAR_MODE_MSK GENMASK(2, 1)
59#define PAR_MODE_SHFT 1
60#define PAR_EVEN 0x00
61#define PAR_ODD 0x01
62#define PAR_SPACE 0x10
63#define PAR_MARK 0x11
64
65/* UART M_CMD OP codes */
66#define UART_START_TX 0x1
67#define UART_START_BREAK 0x4
68#define UART_STOP_BREAK 0x5
69/* UART S_CMD OP codes */
70#define UART_START_READ 0x1
71#define UART_PARAM 0x1
72
73#define UART_OVERSAMPLING 32
74#define STALE_TIMEOUT 16
75#define DEFAULT_BITS_PER_CHAR 10
76#define GENI_UART_CONS_PORTS 1
77#define DEF_FIFO_DEPTH_WORDS 16
78#define DEF_TX_WM 2
79#define DEF_FIFO_WIDTH_BITS 32
80#define UART_CONSOLE_RX_WM 2
81
82#ifdef CONFIG_CONSOLE_POLL
83#define RX_BYTES_PW 1
84#else
85#define RX_BYTES_PW 4
86#endif
87
88struct qcom_geni_serial_port {
89 struct uart_port uport;
90 struct geni_se se;
91 char name[20];
92 u32 tx_fifo_depth;
93 u32 tx_fifo_width;
94 u32 rx_fifo_depth;
95 u32 tx_wm;
96 u32 rx_wm;
97 u32 rx_rfr;
98 enum geni_se_xfer_mode xfer_mode;
99 bool setup;
100 int (*handle_rx)(struct uart_port *uport, u32 bytes, bool drop);
101 unsigned int xmit_size;
102 unsigned int baud;
103 unsigned int tx_bytes_pw;
104 unsigned int rx_bytes_pw;
105 bool brk;
106};
107
108static const struct uart_ops qcom_geni_serial_pops;
109static struct uart_driver qcom_geni_console_driver;
110static int handle_rx_console(struct uart_port *uport, u32 bytes, bool drop);
111static unsigned int qcom_geni_serial_tx_empty(struct uart_port *port);
112static void qcom_geni_serial_stop_rx(struct uart_port *uport);
113
114static const unsigned long root_freq[] = {7372800, 14745600, 19200000, 29491200,
115 32000000, 48000000, 64000000, 80000000,
116 96000000, 100000000};
117
118#define to_dev_port(ptr, member) \
119 container_of(ptr, struct qcom_geni_serial_port, member)
120
121static struct qcom_geni_serial_port qcom_geni_console_port;
122
123static int qcom_geni_serial_request_port(struct uart_port *uport)
124{
125 struct platform_device *pdev = to_platform_device(uport->dev);
126 struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
127 struct resource *res;
128
129 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
130 uport->membase = devm_ioremap_resource(&pdev->dev, res);
131 if (IS_ERR(uport->membase))
132 return PTR_ERR(uport->membase);
133 port->se.base = uport->membase;
134 return 0;
135}
136
137static void qcom_geni_serial_config_port(struct uart_port *uport, int cfg_flags)
138{
139 if (cfg_flags & UART_CONFIG_TYPE) {
140 uport->type = PORT_MSM;
141 qcom_geni_serial_request_port(uport);
142 }
143}
144
145static unsigned int qcom_geni_cons_get_mctrl(struct uart_port *uport)
146{
147 return TIOCM_DSR | TIOCM_CAR | TIOCM_CTS;
148}
149
150static void qcom_geni_cons_set_mctrl(struct uart_port *uport,
151 unsigned int mctrl)
152{
153}
154
155static const char *qcom_geni_serial_get_type(struct uart_port *uport)
156{
157 return "MSM";
158}
159
160static struct qcom_geni_serial_port *get_port_from_line(int line)
161{
162 if (line < 0 || line >= GENI_UART_CONS_PORTS)
163 return ERR_PTR(-ENXIO);
164 return &qcom_geni_console_port;
165}
166
167static bool qcom_geni_serial_poll_bit(struct uart_port *uport,
168 int offset, int field, bool set)
169{
170 u32 reg;
171 struct qcom_geni_serial_port *port;
172 unsigned int baud;
173 unsigned int fifo_bits;
174 unsigned long timeout_us = 20000;
175
176 /* Ensure polling is not re-ordered before the prior writes/reads */
177 mb();
178
179 if (uport->private_data) {
180 port = to_dev_port(uport, uport);
181 baud = port->baud;
182 if (!baud)
183 baud = 115200;
184 fifo_bits = port->tx_fifo_depth * port->tx_fifo_width;
185 /*
186 * Total polling iterations based on FIFO worth of bytes to be
187 * sent at current baud. Add a little fluff to the wait.
188 */
189 timeout_us = ((fifo_bits * USEC_PER_SEC) / baud) + 500;
190 }
191
192 return !readl_poll_timeout_atomic(uport->membase + offset, reg,
193 (bool)(reg & field) == set, 10, timeout_us);
194}
195
196static void qcom_geni_serial_setup_tx(struct uart_port *uport, u32 xmit_size)
197{
198 u32 m_cmd;
199
200 writel_relaxed(xmit_size, uport->membase + SE_UART_TX_TRANS_LEN);
201 m_cmd = UART_START_TX << M_OPCODE_SHFT;
202 writel(m_cmd, uport->membase + SE_GENI_M_CMD0);
203}
204
205static void qcom_geni_serial_poll_tx_done(struct uart_port *uport)
206{
207 int done;
208 u32 irq_clear = M_CMD_DONE_EN;
209
210 done = qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS,
211 M_CMD_DONE_EN, true);
212 if (!done) {
213 writel_relaxed(M_GENI_CMD_ABORT, uport->membase +
214 SE_GENI_M_CMD_CTRL_REG);
215 irq_clear |= M_CMD_ABORT_EN;
216 qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS,
217 M_CMD_ABORT_EN, true);
218 }
219 writel_relaxed(irq_clear, uport->membase + SE_GENI_M_IRQ_CLEAR);
220}
221
222static void qcom_geni_serial_abort_rx(struct uart_port *uport)
223{
224 u32 irq_clear = S_CMD_DONE_EN | S_CMD_ABORT_EN;
225
226 writel(S_GENI_CMD_ABORT, uport->membase + SE_GENI_S_CMD_CTRL_REG);
227 qcom_geni_serial_poll_bit(uport, SE_GENI_S_CMD_CTRL_REG,
228 S_GENI_CMD_ABORT, false);
229 writel_relaxed(irq_clear, uport->membase + SE_GENI_S_IRQ_CLEAR);
230 writel_relaxed(FORCE_DEFAULT, uport->membase + GENI_FORCE_DEFAULT_REG);
231}
232
233#ifdef CONFIG_CONSOLE_POLL
234static int qcom_geni_serial_get_char(struct uart_port *uport)
235{
236 u32 rx_fifo;
237 u32 status;
238
239 status = readl_relaxed(uport->membase + SE_GENI_M_IRQ_STATUS);
240 writel_relaxed(status, uport->membase + SE_GENI_M_IRQ_CLEAR);
241
242 status = readl_relaxed(uport->membase + SE_GENI_S_IRQ_STATUS);
243 writel_relaxed(status, uport->membase + SE_GENI_S_IRQ_CLEAR);
244
245 /*
246 * Ensure the writes to clear interrupts is not re-ordered after
247 * reading the data.
248 */
249 mb();
250
251 status = readl_relaxed(uport->membase + SE_GENI_RX_FIFO_STATUS);
252 if (!(status & RX_FIFO_WC_MSK))
253 return NO_POLL_CHAR;
254
255 rx_fifo = readl(uport->membase + SE_GENI_RX_FIFOn);
256 return rx_fifo & 0xff;
257}
258
259static void qcom_geni_serial_poll_put_char(struct uart_port *uport,
260 unsigned char c)
261{
262 struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
263
264 writel_relaxed(port->tx_wm, uport->membase + SE_GENI_TX_WATERMARK_REG);
265 qcom_geni_serial_setup_tx(uport, 1);
266 WARN_ON(!qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS,
267 M_TX_FIFO_WATERMARK_EN, true));
268 writel_relaxed(c, uport->membase + SE_GENI_TX_FIFOn);
269 writel_relaxed(M_TX_FIFO_WATERMARK_EN, uport->membase +
270 SE_GENI_M_IRQ_CLEAR);
271 qcom_geni_serial_poll_tx_done(uport);
272}
273#endif
274
275#ifdef CONFIG_SERIAL_QCOM_GENI_CONSOLE
276static void qcom_geni_serial_wr_char(struct uart_port *uport, int ch)
277{
278 writel_relaxed(ch, uport->membase + SE_GENI_TX_FIFOn);
279}
280
281static void
282__qcom_geni_serial_console_write(struct uart_port *uport, const char *s,
283 unsigned int count)
284{
285 int i;
286 u32 bytes_to_send = count;
287
288 for (i = 0; i < count; i++) {
289 if (s[i] == '\n')
290 bytes_to_send++;
291 }
292
293 writel_relaxed(DEF_TX_WM, uport->membase + SE_GENI_TX_WATERMARK_REG);
294 qcom_geni_serial_setup_tx(uport, bytes_to_send);
295 for (i = 0; i < count; ) {
296 size_t chars_to_write = 0;
297 size_t avail = DEF_FIFO_DEPTH_WORDS - DEF_TX_WM;
298
299 /*
300 * If the WM bit never set, then the Tx state machine is not
301 * in a valid state, so break, cancel/abort any existing
302 * command. Unfortunately the current data being written is
303 * lost.
304 */
305 if (!qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS,
306 M_TX_FIFO_WATERMARK_EN, true))
307 break;
308 chars_to_write = min_t(size_t, (size_t)(count - i), avail / 2);
309 uart_console_write(uport, s + i, chars_to_write,
310 qcom_geni_serial_wr_char);
311 writel_relaxed(M_TX_FIFO_WATERMARK_EN, uport->membase +
312 SE_GENI_M_IRQ_CLEAR);
313 i += chars_to_write;
314 }
315 qcom_geni_serial_poll_tx_done(uport);
316}
317
318static void qcom_geni_serial_console_write(struct console *co, const char *s,
319 unsigned int count)
320{
321 struct uart_port *uport;
322 struct qcom_geni_serial_port *port;
323 bool locked = true;
324 unsigned long flags;
325
326 WARN_ON(co->index < 0 || co->index >= GENI_UART_CONS_PORTS);
327
328 port = get_port_from_line(co->index);
329 if (IS_ERR(port))
330 return;
331
332 uport = &port->uport;
333 if (oops_in_progress)
334 locked = spin_trylock_irqsave(&uport->lock, flags);
335 else
336 spin_lock_irqsave(&uport->lock, flags);
337
338 /* Cancel the current write to log the fault */
339 if (!locked) {
340 geni_se_cancel_m_cmd(&port->se);
341 if (!qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS,
342 M_CMD_CANCEL_EN, true)) {
343 geni_se_abort_m_cmd(&port->se);
344 qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS,
345 M_CMD_ABORT_EN, true);
346 writel_relaxed(M_CMD_ABORT_EN, uport->membase +
347 SE_GENI_M_IRQ_CLEAR);
348 }
349 writel_relaxed(M_CMD_CANCEL_EN, uport->membase +
350 SE_GENI_M_IRQ_CLEAR);
351 }
352
353 __qcom_geni_serial_console_write(uport, s, count);
354 if (locked)
355 spin_unlock_irqrestore(&uport->lock, flags);
356}
357
358static int handle_rx_console(struct uart_port *uport, u32 bytes, bool drop)
359{
360 u32 i;
361 unsigned char buf[sizeof(u32)];
362 struct tty_port *tport;
363 struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
364
365 tport = &uport->state->port;
366 for (i = 0; i < bytes; ) {
367 int c;
368 int chunk = min_t(int, bytes - i, port->rx_bytes_pw);
369
370 ioread32_rep(uport->membase + SE_GENI_RX_FIFOn, buf, 1);
371 i += chunk;
372 if (drop)
373 continue;
374
375 for (c = 0; c < chunk; c++) {
376 int sysrq;
377
378 uport->icount.rx++;
379 if (port->brk && buf[c] == 0) {
380 port->brk = false;
381 if (uart_handle_break(uport))
382 continue;
383 }
384
385 sysrq = uart_handle_sysrq_char(uport, buf[c]);
386 if (!sysrq)
387 tty_insert_flip_char(tport, buf[c], TTY_NORMAL);
388 }
389 }
390 if (!drop)
391 tty_flip_buffer_push(tport);
392 return 0;
393}
394#else
395static int handle_rx_console(struct uart_port *uport, u32 bytes, bool drop)
396{
397 return -EPERM;
398}
399
400#endif /* CONFIG_SERIAL_QCOM_GENI_CONSOLE */
401
402static void qcom_geni_serial_start_tx(struct uart_port *uport)
403{
404 u32 irq_en;
405 struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
406 u32 status;
407
408 if (port->xfer_mode == GENI_SE_FIFO) {
409 status = readl_relaxed(uport->membase + SE_GENI_STATUS);
410 if (status & M_GENI_CMD_ACTIVE)
411 return;
412
413 if (!qcom_geni_serial_tx_empty(uport))
414 return;
415
416 /*
417 * Ensure writing to IRQ_EN & watermark registers are not
418 * re-ordered before checking the status of the Serial
419 * Engine and TX FIFO
420 */
421 mb();
422
423 irq_en = readl_relaxed(uport->membase + SE_GENI_M_IRQ_EN);
424 irq_en |= M_TX_FIFO_WATERMARK_EN | M_CMD_DONE_EN;
425
426 writel_relaxed(port->tx_wm, uport->membase +
427 SE_GENI_TX_WATERMARK_REG);
428 writel_relaxed(irq_en, uport->membase + SE_GENI_M_IRQ_EN);
429 }
430}
431
432static void qcom_geni_serial_stop_tx(struct uart_port *uport)
433{
434 u32 irq_en;
435 u32 status;
436 struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
437
438 irq_en = readl_relaxed(uport->membase + SE_GENI_M_IRQ_EN);
439 irq_en &= ~M_CMD_DONE_EN;
440 if (port->xfer_mode == GENI_SE_FIFO) {
441 irq_en &= ~M_TX_FIFO_WATERMARK_EN;
442 writel_relaxed(0, uport->membase +
443 SE_GENI_TX_WATERMARK_REG);
444 }
445 port->xmit_size = 0;
446 writel_relaxed(irq_en, uport->membase + SE_GENI_M_IRQ_EN);
447 status = readl_relaxed(uport->membase + SE_GENI_STATUS);
448 /* Possible stop tx is called multiple times. */
449 if (!(status & M_GENI_CMD_ACTIVE))
450 return;
451
452 /*
453 * Ensure cancel command write is not re-ordered before checking
454 * the status of the Primary Sequencer.
455 */
456 mb();
457
458 geni_se_cancel_m_cmd(&port->se);
459 if (!qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS,
460 M_CMD_CANCEL_EN, true)) {
461 geni_se_abort_m_cmd(&port->se);
462 qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS,
463 M_CMD_ABORT_EN, true);
464 writel_relaxed(M_CMD_ABORT_EN, uport->membase +
465 SE_GENI_M_IRQ_CLEAR);
466 }
467 writel_relaxed(M_CMD_CANCEL_EN, uport->membase + SE_GENI_M_IRQ_CLEAR);
468}
469
470static void qcom_geni_serial_start_rx(struct uart_port *uport)
471{
472 u32 irq_en;
473 u32 status;
474 struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
475
476 status = readl_relaxed(uport->membase + SE_GENI_STATUS);
477 if (status & S_GENI_CMD_ACTIVE)
478 qcom_geni_serial_stop_rx(uport);
479
480 /*
481 * Ensure setup command write is not re-ordered before checking
482 * the status of the Secondary Sequencer.
483 */
484 mb();
485
486 geni_se_setup_s_cmd(&port->se, UART_START_READ, 0);
487
488 if (port->xfer_mode == GENI_SE_FIFO) {
489 irq_en = readl_relaxed(uport->membase + SE_GENI_S_IRQ_EN);
490 irq_en |= S_RX_FIFO_WATERMARK_EN | S_RX_FIFO_LAST_EN;
491 writel_relaxed(irq_en, uport->membase + SE_GENI_S_IRQ_EN);
492
493 irq_en = readl_relaxed(uport->membase + SE_GENI_M_IRQ_EN);
494 irq_en |= M_RX_FIFO_WATERMARK_EN | M_RX_FIFO_LAST_EN;
495 writel_relaxed(irq_en, uport->membase + SE_GENI_M_IRQ_EN);
496 }
497}
498
499static void qcom_geni_serial_stop_rx(struct uart_port *uport)
500{
501 u32 irq_en;
502 u32 status;
503 struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
504 u32 irq_clear = S_CMD_DONE_EN;
505
506 if (port->xfer_mode == GENI_SE_FIFO) {
507 irq_en = readl_relaxed(uport->membase + SE_GENI_S_IRQ_EN);
508 irq_en &= ~(S_RX_FIFO_WATERMARK_EN | S_RX_FIFO_LAST_EN);
509 writel_relaxed(irq_en, uport->membase + SE_GENI_S_IRQ_EN);
510
511 irq_en = readl_relaxed(uport->membase + SE_GENI_M_IRQ_EN);
512 irq_en &= ~(M_RX_FIFO_WATERMARK_EN | M_RX_FIFO_LAST_EN);
513 writel_relaxed(irq_en, uport->membase + SE_GENI_M_IRQ_EN);
514 }
515
516 status = readl_relaxed(uport->membase + SE_GENI_STATUS);
517 /* Possible stop rx is called multiple times. */
518 if (!(status & S_GENI_CMD_ACTIVE))
519 return;
520
521 /*
522 * Ensure cancel command write is not re-ordered before checking
523 * the status of the Secondary Sequencer.
524 */
525 mb();
526
527 geni_se_cancel_s_cmd(&port->se);
528 qcom_geni_serial_poll_bit(uport, SE_GENI_S_CMD_CTRL_REG,
529 S_GENI_CMD_CANCEL, false);
530 status = readl_relaxed(uport->membase + SE_GENI_STATUS);
531 writel_relaxed(irq_clear, uport->membase + SE_GENI_S_IRQ_CLEAR);
532 if (status & S_GENI_CMD_ACTIVE)
533 qcom_geni_serial_abort_rx(uport);
534}
535
536static void qcom_geni_serial_handle_rx(struct uart_port *uport, bool drop)
537{
538 u32 status;
539 u32 word_cnt;
540 u32 last_word_byte_cnt;
541 u32 last_word_partial;
542 u32 total_bytes;
543 struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
544
545 status = readl_relaxed(uport->membase + SE_GENI_RX_FIFO_STATUS);
546 word_cnt = status & RX_FIFO_WC_MSK;
547 last_word_partial = status & RX_LAST;
548 last_word_byte_cnt = (status & RX_LAST_BYTE_VALID_MSK) >>
549 RX_LAST_BYTE_VALID_SHFT;
550
551 if (!word_cnt)
552 return;
553 total_bytes = port->rx_bytes_pw * (word_cnt - 1);
554 if (last_word_partial && last_word_byte_cnt)
555 total_bytes += last_word_byte_cnt;
556 else
557 total_bytes += port->rx_bytes_pw;
558 port->handle_rx(uport, total_bytes, drop);
559}
560
561static void qcom_geni_serial_handle_tx(struct uart_port *uport)
562{
563 struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
564 struct circ_buf *xmit = &uport->state->xmit;
565 size_t avail;
566 size_t remaining;
567 int i;
568 u32 status;
569 unsigned int chunk;
570 int tail;
571
572 chunk = uart_circ_chars_pending(xmit);
573 status = readl_relaxed(uport->membase + SE_GENI_TX_FIFO_STATUS);
574 /* Both FIFO and framework buffer are drained */
575 if (chunk == port->xmit_size && !status) {
576 port->xmit_size = 0;
577 uart_circ_clear(xmit);
578 qcom_geni_serial_stop_tx(uport);
579 goto out_write_wakeup;
580 }
581 chunk -= port->xmit_size;
582
583 avail = (port->tx_fifo_depth - port->tx_wm) * port->tx_bytes_pw;
584 tail = (xmit->tail + port->xmit_size) & (UART_XMIT_SIZE - 1);
585 if (chunk > (UART_XMIT_SIZE - tail))
586 chunk = UART_XMIT_SIZE - tail;
587 if (chunk > avail)
588 chunk = avail;
589
590 if (!chunk)
591 goto out_write_wakeup;
592
593 qcom_geni_serial_setup_tx(uport, chunk);
594
595 remaining = chunk;
596 for (i = 0; i < chunk; ) {
597 unsigned int tx_bytes;
598 unsigned int buf = 0;
599 int c;
600
601 tx_bytes = min_t(size_t, remaining, (size_t)port->tx_bytes_pw);
602 for (c = 0; c < tx_bytes ; c++)
603 buf |= (xmit->buf[tail + c] << (c * BITS_PER_BYTE));
604
605 writel_relaxed(buf, uport->membase + SE_GENI_TX_FIFOn);
606
607 i += tx_bytes;
608 tail = (tail + tx_bytes) & (UART_XMIT_SIZE - 1);
609 uport->icount.tx += tx_bytes;
610 remaining -= tx_bytes;
611 }
612 qcom_geni_serial_poll_tx_done(uport);
613 port->xmit_size += chunk;
614out_write_wakeup:
615 uart_write_wakeup(uport);
616}
617
618static irqreturn_t qcom_geni_serial_isr(int isr, void *dev)
619{
620 unsigned int m_irq_status;
621 unsigned int s_irq_status;
622 struct uart_port *uport = dev;
623 unsigned long flags;
624 unsigned int m_irq_en;
625 bool drop_rx = false;
626 struct tty_port *tport = &uport->state->port;
627 struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
628
629 if (uport->suspended)
630 return IRQ_HANDLED;
631
632 spin_lock_irqsave(&uport->lock, flags);
633 m_irq_status = readl_relaxed(uport->membase + SE_GENI_M_IRQ_STATUS);
634 s_irq_status = readl_relaxed(uport->membase + SE_GENI_S_IRQ_STATUS);
635 m_irq_en = readl_relaxed(uport->membase + SE_GENI_M_IRQ_EN);
636 writel_relaxed(m_irq_status, uport->membase + SE_GENI_M_IRQ_CLEAR);
637 writel_relaxed(s_irq_status, uport->membase + SE_GENI_S_IRQ_CLEAR);
638
639 if (WARN_ON(m_irq_status & M_ILLEGAL_CMD_EN))
640 goto out_unlock;
641
642 if (s_irq_status & S_RX_FIFO_WR_ERR_EN) {
643 uport->icount.overrun++;
644 tty_insert_flip_char(tport, 0, TTY_OVERRUN);
645 }
646
647 if (m_irq_status & (M_TX_FIFO_WATERMARK_EN | M_CMD_DONE_EN) &&
648 m_irq_en & (M_TX_FIFO_WATERMARK_EN | M_CMD_DONE_EN))
649 qcom_geni_serial_handle_tx(uport);
650
651 if (s_irq_status & S_GP_IRQ_0_EN || s_irq_status & S_GP_IRQ_1_EN) {
652 if (s_irq_status & S_GP_IRQ_0_EN)
653 uport->icount.parity++;
654 drop_rx = true;
655 } else if (s_irq_status & S_GP_IRQ_2_EN ||
656 s_irq_status & S_GP_IRQ_3_EN) {
657 uport->icount.brk++;
658 port->brk = true;
659 }
660
661 if (s_irq_status & S_RX_FIFO_WATERMARK_EN ||
662 s_irq_status & S_RX_FIFO_LAST_EN)
663 qcom_geni_serial_handle_rx(uport, drop_rx);
664
665out_unlock:
666 spin_unlock_irqrestore(&uport->lock, flags);
667 return IRQ_HANDLED;
668}
669
670static int get_tx_fifo_size(struct qcom_geni_serial_port *port)
671{
672 struct uart_port *uport;
673
674 if (!port)
675 return -ENODEV;
676
677 uport = &port->uport;
678 port->tx_fifo_depth = geni_se_get_tx_fifo_depth(&port->se);
679 port->tx_fifo_width = geni_se_get_tx_fifo_width(&port->se);
680 port->rx_fifo_depth = geni_se_get_rx_fifo_depth(&port->se);
681 uport->fifosize =
682 (port->tx_fifo_depth * port->tx_fifo_width) / BITS_PER_BYTE;
683 return 0;
684}
685
686static void set_rfr_wm(struct qcom_geni_serial_port *port)
687{
688 /*
689 * Set RFR (Flow off) to FIFO_DEPTH - 2.
690 * RX WM level at 10% RX_FIFO_DEPTH.
691 * TX WM level at 10% TX_FIFO_DEPTH.
692 */
693 port->rx_rfr = port->rx_fifo_depth - 2;
694 port->rx_wm = UART_CONSOLE_RX_WM;
695 port->tx_wm = DEF_TX_WM;
696}
697
698static void qcom_geni_serial_shutdown(struct uart_port *uport)
699{
700 unsigned long flags;
701
702 /* Stop the console before stopping the current tx */
703 console_stop(uport->cons);
704
705 disable_irq(uport->irq);
706 free_irq(uport->irq, uport);
707 spin_lock_irqsave(&uport->lock, flags);
708 qcom_geni_serial_stop_tx(uport);
709 qcom_geni_serial_stop_rx(uport);
710 spin_unlock_irqrestore(&uport->lock, flags);
711}
712
713static int qcom_geni_serial_port_setup(struct uart_port *uport)
714{
715 struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
716 unsigned int rxstale = DEFAULT_BITS_PER_CHAR * STALE_TIMEOUT;
717
718 set_rfr_wm(port);
719 writel_relaxed(rxstale, uport->membase + SE_UART_RX_STALE_CNT);
720 /*
721 * Make an unconditional cancel on the main sequencer to reset
722 * it else we could end up in data loss scenarios.
723 */
724 port->xfer_mode = GENI_SE_FIFO;
725 qcom_geni_serial_poll_tx_done(uport);
726 geni_se_config_packing(&port->se, BITS_PER_BYTE, port->tx_bytes_pw,
727 false, true, false);
728 geni_se_config_packing(&port->se, BITS_PER_BYTE, port->rx_bytes_pw,
729 false, false, true);
730 geni_se_init(&port->se, port->rx_wm, port->rx_rfr);
731 geni_se_select_mode(&port->se, port->xfer_mode);
732 port->setup = true;
733 return 0;
734}
735
736static int qcom_geni_serial_startup(struct uart_port *uport)
737{
738 int ret;
739 u32 proto;
740 struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
741
742 scnprintf(port->name, sizeof(port->name),
743 "qcom_serial_geni%d", uport->line);
744
745 proto = geni_se_read_proto(&port->se);
746 if (proto != GENI_SE_UART) {
747 dev_err(uport->dev, "Invalid FW loaded, proto: %d\n", proto);
748 return -ENXIO;
749 }
750
751 get_tx_fifo_size(port);
752 if (!port->setup) {
753 ret = qcom_geni_serial_port_setup(uport);
754 if (ret)
755 return ret;
756 }
757
758 ret = request_irq(uport->irq, qcom_geni_serial_isr, IRQF_TRIGGER_HIGH,
759 port->name, uport);
760 if (ret)
761 dev_err(uport->dev, "Failed to get IRQ ret %d\n", ret);
762 return ret;
763}
764
765static unsigned long get_clk_cfg(unsigned long clk_freq)
766{
767 int i;
768
769 for (i = 0; i < ARRAY_SIZE(root_freq); i++) {
770 if (!(root_freq[i] % clk_freq))
771 return root_freq[i];
772 }
773 return 0;
774}
775
776static unsigned long get_clk_div_rate(unsigned int baud, unsigned int *clk_div)
777{
778 unsigned long ser_clk;
779 unsigned long desired_clk;
780
781 desired_clk = baud * UART_OVERSAMPLING;
782 ser_clk = get_clk_cfg(desired_clk);
783 if (!ser_clk) {
784 pr_err("%s: Can't find matching DFS entry for baud %d\n",
785 __func__, baud);
786 return ser_clk;
787 }
788
789 *clk_div = ser_clk / desired_clk;
790 return ser_clk;
791}
792
793static void qcom_geni_serial_set_termios(struct uart_port *uport,
794 struct ktermios *termios, struct ktermios *old)
795{
796 unsigned int baud;
797 unsigned int bits_per_char;
798 unsigned int tx_trans_cfg;
799 unsigned int tx_parity_cfg;
800 unsigned int rx_trans_cfg;
801 unsigned int rx_parity_cfg;
802 unsigned int stop_bit_len;
803 unsigned int clk_div;
804 unsigned long ser_clk_cfg;
805 struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
806 unsigned long clk_rate;
807
808 qcom_geni_serial_stop_rx(uport);
809 /* baud rate */
810 baud = uart_get_baud_rate(uport, termios, old, 300, 4000000);
811 port->baud = baud;
812 clk_rate = get_clk_div_rate(baud, &clk_div);
813 if (!clk_rate)
814 goto out_restart_rx;
815
816 uport->uartclk = clk_rate;
817 clk_set_rate(port->se.clk, clk_rate);
818 ser_clk_cfg = SER_CLK_EN;
819 ser_clk_cfg |= clk_div << CLK_DIV_SHFT;
820
821 /* parity */
822 tx_trans_cfg = readl_relaxed(uport->membase + SE_UART_TX_TRANS_CFG);
823 tx_parity_cfg = readl_relaxed(uport->membase + SE_UART_TX_PARITY_CFG);
824 rx_trans_cfg = readl_relaxed(uport->membase + SE_UART_RX_TRANS_CFG);
825 rx_parity_cfg = readl_relaxed(uport->membase + SE_UART_RX_PARITY_CFG);
826 if (termios->c_cflag & PARENB) {
827 tx_trans_cfg |= UART_TX_PAR_EN;
828 rx_trans_cfg |= UART_RX_PAR_EN;
829 tx_parity_cfg |= PAR_CALC_EN;
830 rx_parity_cfg |= PAR_CALC_EN;
831 if (termios->c_cflag & PARODD) {
832 tx_parity_cfg |= PAR_ODD;
833 rx_parity_cfg |= PAR_ODD;
834 } else if (termios->c_cflag & CMSPAR) {
835 tx_parity_cfg |= PAR_SPACE;
836 rx_parity_cfg |= PAR_SPACE;
837 } else {
838 tx_parity_cfg |= PAR_EVEN;
839 rx_parity_cfg |= PAR_EVEN;
840 }
841 } else {
842 tx_trans_cfg &= ~UART_TX_PAR_EN;
843 rx_trans_cfg &= ~UART_RX_PAR_EN;
844 tx_parity_cfg &= ~PAR_CALC_EN;
845 rx_parity_cfg &= ~PAR_CALC_EN;
846 }
847
848 /* bits per char */
849 switch (termios->c_cflag & CSIZE) {
850 case CS5:
851 bits_per_char = 5;
852 break;
853 case CS6:
854 bits_per_char = 6;
855 break;
856 case CS7:
857 bits_per_char = 7;
858 break;
859 case CS8:
860 default:
861 bits_per_char = 8;
862 break;
863 }
864
865 /* stop bits */
866 if (termios->c_cflag & CSTOPB)
867 stop_bit_len = TX_STOP_BIT_LEN_2;
868 else
869 stop_bit_len = TX_STOP_BIT_LEN_1;
870
871 /* flow control, clear the CTS_MASK bit if using flow control. */
872 if (termios->c_cflag & CRTSCTS)
873 tx_trans_cfg &= ~UART_CTS_MASK;
874 else
875 tx_trans_cfg |= UART_CTS_MASK;
876
877 if (baud)
878 uart_update_timeout(uport, termios->c_cflag, baud);
879
880 writel_relaxed(tx_trans_cfg, uport->membase + SE_UART_TX_TRANS_CFG);
881 writel_relaxed(tx_parity_cfg, uport->membase + SE_UART_TX_PARITY_CFG);
882 writel_relaxed(rx_trans_cfg, uport->membase + SE_UART_RX_TRANS_CFG);
883 writel_relaxed(rx_parity_cfg, uport->membase + SE_UART_RX_PARITY_CFG);
884 writel_relaxed(bits_per_char, uport->membase + SE_UART_TX_WORD_LEN);
885 writel_relaxed(bits_per_char, uport->membase + SE_UART_RX_WORD_LEN);
886 writel_relaxed(stop_bit_len, uport->membase + SE_UART_TX_STOP_BIT_LEN);
887 writel_relaxed(ser_clk_cfg, uport->membase + GENI_SER_M_CLK_CFG);
888 writel_relaxed(ser_clk_cfg, uport->membase + GENI_SER_S_CLK_CFG);
889out_restart_rx:
890 qcom_geni_serial_start_rx(uport);
891}
892
893static unsigned int qcom_geni_serial_tx_empty(struct uart_port *uport)
894{
895 return !readl_relaxed(uport->membase + SE_GENI_TX_FIFO_STATUS);
896}
897
898#ifdef CONFIG_SERIAL_QCOM_GENI_CONSOLE
899static int __init qcom_geni_console_setup(struct console *co, char *options)
900{
901 struct uart_port *uport;
902 struct qcom_geni_serial_port *port;
903 int baud;
904 int bits = 8;
905 int parity = 'n';
906 int flow = 'n';
907
908 if (co->index >= GENI_UART_CONS_PORTS || co->index < 0)
909 return -ENXIO;
910
911 port = get_port_from_line(co->index);
912 if (IS_ERR(port)) {
913 pr_err("Invalid line %d(%d)\n", co->index, (int)PTR_ERR(port));
914 return PTR_ERR(port);
915 }
916
917 uport = &port->uport;
918
919 if (unlikely(!uport->membase))
920 return -ENXIO;
921
922 if (geni_se_resources_on(&port->se)) {
923 dev_err(port->se.dev, "Error turning on resources\n");
924 return -ENXIO;
925 }
926
927 if (unlikely(geni_se_read_proto(&port->se) != GENI_SE_UART)) {
928 geni_se_resources_off(&port->se);
929 return -ENXIO;
930 }
931
932 if (!port->setup) {
933 port->tx_bytes_pw = 1;
934 port->rx_bytes_pw = RX_BYTES_PW;
935 qcom_geni_serial_stop_rx(uport);
936 qcom_geni_serial_port_setup(uport);
937 }
938
939 if (options)
940 uart_parse_options(options, &baud, &parity, &bits, &flow);
941
942 return uart_set_options(uport, co, baud, parity, bits, flow);
943}
944
945static int __init console_register(struct uart_driver *drv)
946{
947 return uart_register_driver(drv);
948}
949
950static void console_unregister(struct uart_driver *drv)
951{
952 uart_unregister_driver(drv);
953}
954
955static struct console cons_ops = {
956 .name = "ttyMSM",
957 .write = qcom_geni_serial_console_write,
958 .device = uart_console_device,
959 .setup = qcom_geni_console_setup,
960 .flags = CON_PRINTBUFFER,
961 .index = -1,
962 .data = &qcom_geni_console_driver,
963};
964
965static struct uart_driver qcom_geni_console_driver = {
966 .owner = THIS_MODULE,
967 .driver_name = "qcom_geni_console",
968 .dev_name = "ttyMSM",
969 .nr = GENI_UART_CONS_PORTS,
970 .cons = &cons_ops,
971};
972#else
973static int console_register(struct uart_driver *drv)
974{
975 return 0;
976}
977
978static void console_unregister(struct uart_driver *drv)
979{
980}
981#endif /* CONFIG_SERIAL_QCOM_GENI_CONSOLE */
982
983static void qcom_geni_serial_cons_pm(struct uart_port *uport,
984 unsigned int new_state, unsigned int old_state)
985{
986 struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
987
988 if (unlikely(!uart_console(uport)))
989 return;
990
991 if (new_state == UART_PM_STATE_ON && old_state == UART_PM_STATE_OFF)
992 geni_se_resources_on(&port->se);
993 else if (new_state == UART_PM_STATE_OFF &&
994 old_state == UART_PM_STATE_ON)
995 geni_se_resources_off(&port->se);
996}
997
998static const struct uart_ops qcom_geni_console_pops = {
999 .tx_empty = qcom_geni_serial_tx_empty,
1000 .stop_tx = qcom_geni_serial_stop_tx,
1001 .start_tx = qcom_geni_serial_start_tx,
1002 .stop_rx = qcom_geni_serial_stop_rx,
1003 .set_termios = qcom_geni_serial_set_termios,
1004 .startup = qcom_geni_serial_startup,
1005 .request_port = qcom_geni_serial_request_port,
1006 .config_port = qcom_geni_serial_config_port,
1007 .shutdown = qcom_geni_serial_shutdown,
1008 .type = qcom_geni_serial_get_type,
1009 .set_mctrl = qcom_geni_cons_set_mctrl,
1010 .get_mctrl = qcom_geni_cons_get_mctrl,
1011#ifdef CONFIG_CONSOLE_POLL
1012 .poll_get_char = qcom_geni_serial_get_char,
1013 .poll_put_char = qcom_geni_serial_poll_put_char,
1014#endif
1015 .pm = qcom_geni_serial_cons_pm,
1016};
1017
1018static int qcom_geni_serial_probe(struct platform_device *pdev)
1019{
1020 int ret = 0;
1021 int line = -1;
1022 struct qcom_geni_serial_port *port;
1023 struct uart_port *uport;
1024 struct resource *res;
1025 int irq;
1026
1027 if (pdev->dev.of_node)
1028 line = of_alias_get_id(pdev->dev.of_node, "serial");
1029 else
1030 line = pdev->id;
1031
1032 if (line < 0 || line >= GENI_UART_CONS_PORTS)
1033 return -ENXIO;
1034 port = get_port_from_line(line);
1035 if (IS_ERR(port)) {
1036 ret = PTR_ERR(port);
1037 dev_err(&pdev->dev, "Invalid line %d(%d)\n", line, ret);
1038 return ret;
1039 }
1040
1041 uport = &port->uport;
1042 /* Don't allow 2 drivers to access the same port */
1043 if (uport->private_data)
1044 return -ENODEV;
1045
1046 uport->dev = &pdev->dev;
1047 port->se.dev = &pdev->dev;
1048 port->se.wrapper = dev_get_drvdata(pdev->dev.parent);
1049 port->se.clk = devm_clk_get(&pdev->dev, "se");
1050 if (IS_ERR(port->se.clk)) {
1051 ret = PTR_ERR(port->se.clk);
1052 dev_err(&pdev->dev, "Err getting SE Core clk %d\n", ret);
1053 return ret;
1054 }
1055
1056 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1057 if (!res)
1058 return -EINVAL;
1059 uport->mapbase = res->start;
1060
1061 port->tx_fifo_depth = DEF_FIFO_DEPTH_WORDS;
1062 port->rx_fifo_depth = DEF_FIFO_DEPTH_WORDS;
1063 port->tx_fifo_width = DEF_FIFO_WIDTH_BITS;
1064
1065 irq = platform_get_irq(pdev, 0);
1066 if (irq < 0) {
1067 dev_err(&pdev->dev, "Failed to get IRQ %d\n", irq);
1068 return irq;
1069 }
1070 uport->irq = irq;
1071
1072 uport->private_data = &qcom_geni_console_driver;
1073 platform_set_drvdata(pdev, port);
1074 port->handle_rx = handle_rx_console;
1075 port->setup = false;
1076 return uart_add_one_port(&qcom_geni_console_driver, uport);
1077}
1078
1079static int qcom_geni_serial_remove(struct platform_device *pdev)
1080{
1081 struct qcom_geni_serial_port *port = platform_get_drvdata(pdev);
1082 struct uart_driver *drv = port->uport.private_data;
1083
1084 uart_remove_one_port(drv, &port->uport);
1085 return 0;
1086}
1087
1088static int __maybe_unused qcom_geni_serial_sys_suspend_noirq(struct device *dev)
1089{
1090 struct platform_device *pdev = to_platform_device(dev);
1091 struct qcom_geni_serial_port *port = platform_get_drvdata(pdev);
1092 struct uart_port *uport = &port->uport;
1093
1094 uart_suspend_port(uport->private_data, uport);
1095 return 0;
1096}
1097
1098static int __maybe_unused qcom_geni_serial_sys_resume_noirq(struct device *dev)
1099{
1100 struct platform_device *pdev = to_platform_device(dev);
1101 struct qcom_geni_serial_port *port = platform_get_drvdata(pdev);
1102 struct uart_port *uport = &port->uport;
1103
1104 if (console_suspend_enabled && uport->suspended) {
1105 uart_resume_port(uport->private_data, uport);
1106 disable_irq(uport->irq);
1107 }
1108 return 0;
1109}
1110
1111static const struct dev_pm_ops qcom_geni_serial_pm_ops = {
1112 SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(qcom_geni_serial_sys_suspend_noirq,
1113 qcom_geni_serial_sys_resume_noirq)
1114};
1115
1116static const struct of_device_id qcom_geni_serial_match_table[] = {
1117 { .compatible = "qcom,geni-debug-uart", },
1118 {}
1119};
1120MODULE_DEVICE_TABLE(of, qcom_geni_serial_match_table);
1121
1122static struct platform_driver qcom_geni_serial_platform_driver = {
1123 .remove = qcom_geni_serial_remove,
1124 .probe = qcom_geni_serial_probe,
1125 .driver = {
1126 .name = "qcom_geni_serial",
1127 .of_match_table = qcom_geni_serial_match_table,
1128 .pm = &qcom_geni_serial_pm_ops,
1129 },
1130};
1131
1132static int __init qcom_geni_serial_init(void)
1133{
1134 int ret;
1135
1136 qcom_geni_console_port.uport.iotype = UPIO_MEM;
1137 qcom_geni_console_port.uport.ops = &qcom_geni_console_pops;
1138 qcom_geni_console_port.uport.flags = UPF_BOOT_AUTOCONF;
1139 qcom_geni_console_port.uport.line = 0;
1140
1141 ret = console_register(&qcom_geni_console_driver);
1142 if (ret)
1143 return ret;
1144
1145 ret = platform_driver_register(&qcom_geni_serial_platform_driver);
1146 if (ret)
1147 console_unregister(&qcom_geni_console_driver);
1148 return ret;
1149}
1150module_init(qcom_geni_serial_init);
1151
1152static void __exit qcom_geni_serial_exit(void)
1153{
1154 platform_driver_unregister(&qcom_geni_serial_platform_driver);
1155 console_unregister(&qcom_geni_console_driver);
1156}
1157module_exit(qcom_geni_serial_exit);
1158
1159MODULE_DESCRIPTION("Serial driver for GENI based QUP cores");
1160MODULE_LICENSE("GPL v2");