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serial: Convert uart_{,port_}startup() init_hw param to bool
[linux-block.git] / drivers / mmc / core / sdio_uart.c
CommitLineData
2874c5fd 1// SPDX-License-Identifier: GPL-2.0-or-later
6e418a9d 2/*
f397c8d8 3 * SDIO UART/GPS driver
6e418a9d
NP		 4 *
5 * Based on drivers/serial/8250.c and drivers/serial/serial_core.c
6 * by Russell King.
7 *
8 * Author: Nicolas Pitre
9 * Created: June 15, 2007
10 * Copyright: MontaVista Software, Inc.
6e418a9d
NP		 11 */
12
13/*
14 * Note: Although this driver assumes a 16550A-like UART implementation,
15 * it is not possible to leverage the common 8250/16550 driver, nor the
16 * core UART infrastructure, as they assumes direct access to the hardware
17 * registers, often under a spinlock. This is not possible in the SDIO
18 * context as SDIO access functions must be able to sleep.
19 *
20 * Because we need to lock the SDIO host to ensure an exclusive access to
21 * the card, we simply rely on that lock to also prevent and serialize
22 * concurrent access to the same port.
23 */
24
25#include <linux/module.h>
26#include <linux/init.h>
27#include <linux/kernel.h>
4b3b49bb 28#include <linux/sched.h>
6e418a9d 29#include <linux/mutex.h>
201a50ba 30#include <linux/seq_file.h>
834119f5 31#include <linux/serial.h>
6e418a9d
NP		 32#include <linux/serial_reg.h>
33#include <linux/circ_buf.h>
6e418a9d
NP		 34#include <linux/tty.h>
35#include <linux/tty_flip.h>
8b197a5c 36#include <linux/kfifo.h>
5a0e3ad6 37#include <linux/slab.h>
6e418a9d
NP		 38
39#include <linux/mmc/core.h>
40#include <linux/mmc/card.h>
41#include <linux/mmc/sdio_func.h>
42#include <linux/mmc/sdio_ids.h>
43
44
45#define UART_NR 8 /* Number of UARTs this driver can handle */
46
47
8b197a5c 48#define FIFO_SIZE PAGE_SIZE
6e418a9d
NP		 49#define WAKEUP_CHARS 256
50
6e418a9d
NP		 51struct uart_icount {
52 __u32 cts;
53 __u32 dsr;
54 __u32 rng;
55 __u32 dcd;
56 __u32 rx;
57 __u32 tx;
58 __u32 frame;
59 __u32 overrun;
60 __u32 parity;
61 __u32 brk;
62};
63
64struct sdio_uart_port {
b5849b1a 65 struct tty_port port;
6e418a9d 66 unsigned int index;
6e418a9d
NP		 67 struct sdio_func *func;
68 struct mutex func_lock;
15b82b46 69 struct task_struct *in_sdio_uart_irq;
6e418a9d 70 unsigned int regs_offset;
8b197a5c 71 struct kfifo xmit_fifo;
6e418a9d
NP		 72 spinlock_t write_lock;
73 struct uart_icount icount;
74 unsigned int uartclk;
75 unsigned int mctrl;
4b3b49bb 76 unsigned int rx_mctrl;
6e418a9d
NP		 77 unsigned int read_status_mask;
78 unsigned int ignore_status_mask;
79 unsigned char x_char;
80 unsigned char ier;
81 unsigned char lcr;
82};
83
84static struct sdio_uart_port *sdio_uart_table[UART_NR];
85static DEFINE_SPINLOCK(sdio_uart_table_lock);
86
87static int sdio_uart_add_port(struct sdio_uart_port *port)
88{
89 int index, ret = -EBUSY;
90
6e418a9d
NP		 91 mutex_init(&port->func_lock);
92 spin_lock_init(&port->write_lock);
8b197a5c
AC		 93 if (kfifo_alloc(&port->xmit_fifo, FIFO_SIZE, GFP_KERNEL))
94 return -ENOMEM;
6e418a9d
NP		 95
96 spin_lock(&sdio_uart_table_lock);
97 for (index = 0; index < UART_NR; index++) {
98 if (!sdio_uart_table[index]) {
99 port->index = index;
100 sdio_uart_table[index] = port;
101 ret = 0;
102 break;
103 }
104 }
105 spin_unlock(&sdio_uart_table_lock);
106
107 return ret;
108}
109
110static struct sdio_uart_port *sdio_uart_port_get(unsigned index)
111{
112 struct sdio_uart_port *port;
113
114 if (index >= UART_NR)
115 return NULL;
116
117 spin_lock(&sdio_uart_table_lock);
118 port = sdio_uart_table[index];
119 if (port)
e70c6771 120 tty_port_get(&port->port);
6e418a9d
NP		 121 spin_unlock(&sdio_uart_table_lock);
122
123 return port;
124}
125
6e418a9d
NP		 126static void sdio_uart_port_put(struct sdio_uart_port *port)
127{
e70c6771 128 tty_port_put(&port->port);
6e418a9d
NP		 129}
130
131static void sdio_uart_port_remove(struct sdio_uart_port *port)
132{
133 struct sdio_func *func;
134
6e418a9d
NP		 135 spin_lock(&sdio_uart_table_lock);
136 sdio_uart_table[port->index] = NULL;
137 spin_unlock(&sdio_uart_table_lock);
138
139 /*
140 * We're killing a port that potentially still is in use by
141 * the tty layer. Be careful to prevent any further access
142 * to the SDIO function and arrange for the tty layer to
143 * give up on that port ASAP.
144 * Beware: the lock ordering is critical.
145 */
0a68f64f 146 mutex_lock(&port->port.mutex);
6e418a9d
NP		 147 mutex_lock(&port->func_lock);
148 func = port->func;
149 sdio_claim_host(func);
150 port->func = NULL;
151 mutex_unlock(&port->func_lock);
584abc37 152 /* tty_hangup is async so is this safe as is ?? */
aa27a094 153 tty_port_tty_hangup(&port->port, false);
0a68f64f 154 mutex_unlock(&port->port.mutex);
6e418a9d
NP		 155 sdio_release_irq(func);
156 sdio_disable_func(func);
157 sdio_release_host(func);
158
159 sdio_uart_port_put(port);
160}
161
162static int sdio_uart_claim_func(struct sdio_uart_port *port)
163{
164 mutex_lock(&port->func_lock);
165 if (unlikely(!port->func)) {
166 mutex_unlock(&port->func_lock);
167 return -ENODEV;
168 }
15b82b46
NP		 169 if (likely(port->in_sdio_uart_irq != current))
170 sdio_claim_host(port->func);
6e418a9d
NP		 171 mutex_unlock(&port->func_lock);
172 return 0;
173}
174
175static inline void sdio_uart_release_func(struct sdio_uart_port *port)
176{
15b82b46
NP		 177 if (likely(port->in_sdio_uart_irq != current))
178 sdio_release_host(port->func);
6e418a9d
NP		 179}
180
181static inline unsigned int sdio_in(struct sdio_uart_port *port, int offset)
182{
183 unsigned char c;
184 c = sdio_readb(port->func, port->regs_offset + offset, NULL);
185 return c;
186}
187
188static inline void sdio_out(struct sdio_uart_port *port, int offset, int value)
189{
190 sdio_writeb(port->func, value, port->regs_offset + offset, NULL);
191}
192
193static unsigned int sdio_uart_get_mctrl(struct sdio_uart_port *port)
194{
195 unsigned char status;
196 unsigned int ret;
197
4b3b49bb
AC		 198 /* FIXME: What stops this losing the delta bits and breaking
199 sdio_uart_check_modem_status ? */
6e418a9d
NP		 200 status = sdio_in(port, UART_MSR);
201
202 ret = 0;
203 if (status & UART_MSR_DCD)
204 ret |= TIOCM_CAR;
205 if (status & UART_MSR_RI)
206 ret |= TIOCM_RNG;
207 if (status & UART_MSR_DSR)
208 ret |= TIOCM_DSR;
209 if (status & UART_MSR_CTS)
210 ret |= TIOCM_CTS;
211 return ret;
212}
213
1e04b7ae
TLSC		 214static void sdio_uart_write_mctrl(struct sdio_uart_port *port,
215 unsigned int mctrl)
6e418a9d
NP		 216{
217 unsigned char mcr = 0;
218
219 if (mctrl & TIOCM_RTS)
220 mcr |= UART_MCR_RTS;
221 if (mctrl & TIOCM_DTR)
222 mcr |= UART_MCR_DTR;
223 if (mctrl & TIOCM_OUT1)
224 mcr |= UART_MCR_OUT1;
225 if (mctrl & TIOCM_OUT2)
226 mcr |= UART_MCR_OUT2;
227 if (mctrl & TIOCM_LOOP)
228 mcr |= UART_MCR_LOOP;
229
230 sdio_out(port, UART_MCR, mcr);
231}
232
233static inline void sdio_uart_update_mctrl(struct sdio_uart_port *port,
234 unsigned int set, unsigned int clear)
235{
236 unsigned int old;
237
238 old = port->mctrl;
239 port->mctrl = (old & ~clear) | set;
240 if (old != port->mctrl)
241 sdio_uart_write_mctrl(port, port->mctrl);
242}
243
244#define sdio_uart_set_mctrl(port, x) sdio_uart_update_mctrl(port, x, 0)
245#define sdio_uart_clear_mctrl(port, x) sdio_uart_update_mctrl(port, 0, x)
246
247static void sdio_uart_change_speed(struct sdio_uart_port *port,
248 struct ktermios *termios,
a8c11c15 249 const struct ktermios *old)
6e418a9d
NP		 250{
251 unsigned char cval, fcr = 0;
252 unsigned int baud, quot;
253
834119f5 254 cval = UART_LCR_WLEN(tty_get_char_size(termios->c_cflag));
6e418a9d
NP		 255
256 if (termios->c_cflag & CSTOPB)
257 cval |= UART_LCR_STOP;
258 if (termios->c_cflag & PARENB)
259 cval |= UART_LCR_PARITY;
260 if (!(termios->c_cflag & PARODD))
261 cval |= UART_LCR_EPAR;
262
263 for (;;) {
264 baud = tty_termios_baud_rate(termios);
265 if (baud == 0)
266 baud = 9600; /* Special case: B0 rate. */
267 if (baud <= port->uartclk)
268 break;
269 /*
270 * Oops, the quotient was zero. Try again with the old
271 * baud rate if possible, otherwise default to 9600.
272 */
273 termios->c_cflag &= ~CBAUD;
274 if (old) {
275 termios->c_cflag |= old->c_cflag & CBAUD;
276 old = NULL;
277 } else
278 termios->c_cflag |= B9600;
279 }
280 quot = (2 * port->uartclk + baud) / (2 * baud);
281
282 if (baud < 2400)
283 fcr = UART_FCR_ENABLE_FIFO | UART_FCR_TRIGGER_1;
284 else
285 fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10;
286
287 port->read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
288 if (termios->c_iflag & INPCK)
289 port->read_status_mask |= UART_LSR_FE | UART_LSR_PE;
290 if (termios->c_iflag & (BRKINT | PARMRK))
291 port->read_status_mask |= UART_LSR_BI;
292
293 /*
294 * Characters to ignore
295 */
296 port->ignore_status_mask = 0;
297 if (termios->c_iflag & IGNPAR)
298 port->ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
299 if (termios->c_iflag & IGNBRK) {
300 port->ignore_status_mask |= UART_LSR_BI;
301 /*
302 * If we're ignoring parity and break indicators,
303 * ignore overruns too (for real raw support).
304 */
305 if (termios->c_iflag & IGNPAR)
306 port->ignore_status_mask |= UART_LSR_OE;
307 }
308
309 /*
310 * ignore all characters if CREAD is not set
311 */
312 if ((termios->c_cflag & CREAD) == 0)
313 port->ignore_status_mask |= UART_LSR_DR;
314
315 /*
316 * CTS flow control flag and modem status interrupts
317 */
318 port->ier &= ~UART_IER_MSI;
319 if ((termios->c_cflag & CRTSCTS) || !(termios->c_cflag & CLOCAL))
320 port->ier |= UART_IER_MSI;
321
322 port->lcr = cval;
323
324 sdio_out(port, UART_IER, port->ier);
325 sdio_out(port, UART_LCR, cval | UART_LCR_DLAB);
326 sdio_out(port, UART_DLL, quot & 0xff);
327 sdio_out(port, UART_DLM, quot >> 8);
328 sdio_out(port, UART_LCR, cval);
329 sdio_out(port, UART_FCR, fcr);
330
331 sdio_uart_write_mctrl(port, port->mctrl);
332}
333
334static void sdio_uart_start_tx(struct sdio_uart_port *port)
335{
336 if (!(port->ier & UART_IER_THRI)) {
337 port->ier |= UART_IER_THRI;
338 sdio_out(port, UART_IER, port->ier);
339 }
340}
341
342static void sdio_uart_stop_tx(struct sdio_uart_port *port)
343{
344 if (port->ier & UART_IER_THRI) {
345 port->ier &= ~UART_IER_THRI;
346 sdio_out(port, UART_IER, port->ier);
347 }
348}
349
350static void sdio_uart_stop_rx(struct sdio_uart_port *port)
351{
352 port->ier &= ~UART_IER_RLSI;
353 port->read_status_mask &= ~UART_LSR_DR;
354 sdio_out(port, UART_IER, port->ier);
355}
356
1e04b7ae
TLSC		 357static void sdio_uart_receive_chars(struct sdio_uart_port *port,
358 unsigned int *status)
6e418a9d 359{
6e418a9d
NP		 360 unsigned int ch, flag;
361 int max_count = 256;
362
363 do {
364 ch = sdio_in(port, UART_RX);
365 flag = TTY_NORMAL;
366 port->icount.rx++;
367
368 if (unlikely(*status & (UART_LSR_BI | UART_LSR_PE |
1e04b7ae 369 UART_LSR_FE | UART_LSR_OE))) {
6e418a9d
NP		 370 /*
371 * For statistics only
372 */
373 if (*status & UART_LSR_BI) {
374 *status &= ~(UART_LSR_FE | UART_LSR_PE);
375 port->icount.brk++;
376 } else if (*status & UART_LSR_PE)
377 port->icount.parity++;
378 else if (*status & UART_LSR_FE)
379 port->icount.frame++;
380 if (*status & UART_LSR_OE)
381 port->icount.overrun++;
382
383 /*
384 * Mask off conditions which should be ignored.
385 */
386 *status &= port->read_status_mask;
1e04b7ae 387 if (*status & UART_LSR_BI)
6e418a9d 388 flag = TTY_BREAK;
1e04b7ae 389 else if (*status & UART_LSR_PE)
6e418a9d
NP		 390 flag = TTY_PARITY;
391 else if (*status & UART_LSR_FE)
392 flag = TTY_FRAME;
393 }
394
395 if ((*status & port->ignore_status_mask & ~UART_LSR_OE) == 0)
2e124b4a 396 tty_insert_flip_char(&port->port, ch, flag);
6e418a9d
NP		 397
398 /*
399 * Overrun is special. Since it's reported immediately,
400 * it doesn't affect the current character.
401 */
402 if (*status & ~port->ignore_status_mask & UART_LSR_OE)
2e124b4a 403 tty_insert_flip_char(&port->port, 0, TTY_OVERRUN);
6e418a9d
NP		 404
405 *status = sdio_in(port, UART_LSR);
406 } while ((*status & UART_LSR_DR) && (max_count-- > 0));
2e124b4a
JS		 407
408 tty_flip_buffer_push(&port->port);
6e418a9d
NP		 409}
410
411static void sdio_uart_transmit_chars(struct sdio_uart_port *port)
412{
8b197a5c 413 struct kfifo *xmit = &port->xmit_fifo;
6e418a9d 414 int count;
530646f4 415 struct tty_struct *tty;
8b197a5c
AC		 416 u8 iobuf[16];
417 int len;
6e418a9d
NP		 418
419 if (port->x_char) {
420 sdio_out(port, UART_TX, port->x_char);
421 port->icount.tx++;
422 port->x_char = 0;
423 return;
424 }
530646f4
AC		 425
426 tty = tty_port_tty_get(&port->port);
427
8b197a5c 428 if (tty == NULL || !kfifo_len(xmit) ||
6e94dbc7 429 tty->flow.stopped || tty->hw_stopped) {
6e418a9d 430 sdio_uart_stop_tx(port);
530646f4 431 tty_kref_put(tty);
6e418a9d
NP		 432 return;
433 }
434
8b197a5c
AC		 435 len = kfifo_out_locked(xmit, iobuf, 16, &port->write_lock);
436 for (count = 0; count < len; count++) {
437 sdio_out(port, UART_TX, iobuf[count]);
6e418a9d 438 port->icount.tx++;
8b197a5c 439 }
6e418a9d 440
8b197a5c
AC		 441 len = kfifo_len(xmit);
442 if (len < WAKEUP_CHARS) {
b5849b1a 443 tty_wakeup(tty);
8b197a5c
AC		 444 if (len == 0)
445 sdio_uart_stop_tx(port);
446 }
530646f4 447 tty_kref_put(tty);
6e418a9d
NP		 448}
449
450static void sdio_uart_check_modem_status(struct sdio_uart_port *port)
451{
452 int status;
530646f4 453 struct tty_struct *tty;
6e418a9d
NP		 454
455 status = sdio_in(port, UART_MSR);
456
457 if ((status & UART_MSR_ANY_DELTA) == 0)
458 return;
459
460 if (status & UART_MSR_TERI)
461 port->icount.rng++;
462 if (status & UART_MSR_DDSR)
463 port->icount.dsr++;
4b3b49bb 464 if (status & UART_MSR_DDCD) {
6e418a9d 465 port->icount.dcd++;
4b3b49bb
AC		 466 /* DCD raise - wake for open */
467 if (status & UART_MSR_DCD)
468 wake_up_interruptible(&port->port.open_wait);
469 else {
470 /* DCD drop - hang up if tty attached */
aa27a094 471 tty_port_tty_hangup(&port->port, false);
4b3b49bb
AC		 472 }
473 }
6e418a9d
NP		 474 if (status & UART_MSR_DCTS) {
475 port->icount.cts++;
530646f4 476 tty = tty_port_tty_get(&port->port);
9db276f8 477 if (tty && C_CRTSCTS(tty)) {
6e418a9d 478 int cts = (status & UART_MSR_CTS);
b5849b1a 479 if (tty->hw_stopped) {
6e418a9d 480 if (cts) {
b5849b1a 481 tty->hw_stopped = 0;
6e418a9d 482 sdio_uart_start_tx(port);
b5849b1a 483 tty_wakeup(tty);
6e418a9d
NP		 484 }
485 } else {
486 if (!cts) {
b5849b1a 487 tty->hw_stopped = 1;
6e418a9d
NP		 488 sdio_uart_stop_tx(port);
489 }
490 }
491 }
530646f4 492 tty_kref_put(tty);
6e418a9d
NP		 493 }
494}
495
496/*
497 * This handles the interrupt from one port.
498 */
499static void sdio_uart_irq(struct sdio_func *func)
500{
501 struct sdio_uart_port *port = sdio_get_drvdata(func);
502 unsigned int iir, lsr;
503
15b82b46
NP		 504 /*
505 * In a few places sdio_uart_irq() is called directly instead of
506 * waiting for the actual interrupt to be raised and the SDIO IRQ
507 * thread scheduled in order to reduce latency. However, some
508 * interaction with the tty core may end up calling us back
509 * (serial echo, flow control, etc.) through those same places
510 * causing undesirable effects. Let's stop the recursion here.
511 */
512 if (unlikely(port->in_sdio_uart_irq == current))
513 return;
514
6e418a9d
NP		 515 iir = sdio_in(port, UART_IIR);
516 if (iir & UART_IIR_NO_INT)
517 return;
15b82b46
NP		 518
519 port->in_sdio_uart_irq = current;
6e418a9d
NP		 520 lsr = sdio_in(port, UART_LSR);
521 if (lsr & UART_LSR_DR)
522 sdio_uart_receive_chars(port, &lsr);
523 sdio_uart_check_modem_status(port);
524 if (lsr & UART_LSR_THRE)
525 sdio_uart_transmit_chars(port);
15b82b46 526 port->in_sdio_uart_irq = NULL;
6e418a9d
NP		 527}
528
4b3b49bb
AC		 529static int uart_carrier_raised(struct tty_port *tport)
530{
531 struct sdio_uart_port *port =
532 container_of(tport, struct sdio_uart_port, port);
533 unsigned int ret = sdio_uart_claim_func(port);
c9404c9c 534 if (ret) /* Missing hardware shouldn't block for carrier */
4b3b49bb
AC		 535 return 1;
536 ret = sdio_uart_get_mctrl(port);
537 sdio_uart_release_func(port);
538 if (ret & TIOCM_CAR)
539 return 1;
540 return 0;
541}
542
584abc37
AC		 543/**
544 * uart_dtr_rts - port helper to set uart signals
545 * @tport: tty port to be updated
546 * @onoff: set to turn on DTR/RTS
547 *
548 * Called by the tty port helpers when the modem signals need to be
549 * adjusted during an open, close and hangup.
550 */
551
552static void uart_dtr_rts(struct tty_port *tport, int onoff)
6e418a9d 553{
584abc37
AC		 554 struct sdio_uart_port *port =
555 container_of(tport, struct sdio_uart_port, port);
1f100b32
AC		 556 int ret = sdio_uart_claim_func(port);
557 if (ret)
558 return;
584abc37
AC		 559 if (onoff == 0)
560 sdio_uart_clear_mctrl(port, TIOCM_DTR | TIOCM_RTS);
561 else
562 sdio_uart_set_mctrl(port, TIOCM_DTR | TIOCM_RTS);
1f100b32 563 sdio_uart_release_func(port);
584abc37 564}
530646f4 565
584abc37
AC		 566/**
567 * sdio_uart_activate - start up hardware
568 * @tport: tty port to activate
569 * @tty: tty bound to this port
570 *
571 * Activate a tty port. The port locking guarantees us this will be
572 * run exactly once per set of opens, and if successful will see the
573 * shutdown method run exactly once to match. Start up and shutdown are
574 * protected from each other by the internal locking and will not run
575 * at the same time even during a hangup event.
576 *
577 * If we successfully start up the port we take an extra kref as we
578 * will keep it around until shutdown when the kref is dropped.
579 */
580
581static int sdio_uart_activate(struct tty_port *tport, struct tty_struct *tty)
582{
583 struct sdio_uart_port *port =
584 container_of(tport, struct sdio_uart_port, port);
584abc37 585 int ret;
6e418a9d
NP		 586
587 /*
588 * Set the TTY IO error marker - we will only clear this
589 * once we have successfully opened the port.
590 */
b5849b1a 591 set_bit(TTY_IO_ERROR, &tty->flags);
6e418a9d 592
8b197a5c 593 kfifo_reset(&port->xmit_fifo);
6e418a9d
NP		 594
595 ret = sdio_uart_claim_func(port);
596 if (ret)
8b197a5c 597 return ret;
6e418a9d
NP		 598 ret = sdio_enable_func(port->func);
599 if (ret)
8b197a5c 600 goto err1;
6e418a9d
NP		 601 ret = sdio_claim_irq(port->func, sdio_uart_irq);
602 if (ret)
8b197a5c 603 goto err2;
6e418a9d
NP		 604
605 /*
606 * Clear the FIFO buffers and disable them.
607 * (they will be reenabled in sdio_change_speed())
608 */
609 sdio_out(port, UART_FCR, UART_FCR_ENABLE_FIFO);
610 sdio_out(port, UART_FCR, UART_FCR_ENABLE_FIFO |
1e04b7ae 611 UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
6e418a9d
NP		 612 sdio_out(port, UART_FCR, 0);
613
614 /*
615 * Clear the interrupt registers.
616 */
617 (void) sdio_in(port, UART_LSR);
618 (void) sdio_in(port, UART_RX);
619 (void) sdio_in(port, UART_IIR);
620 (void) sdio_in(port, UART_MSR);
621
622 /*
623 * Now, initialize the UART
624 */
625 sdio_out(port, UART_LCR, UART_LCR_WLEN8);
626
c271cf37 627 port->ier = UART_IER_RLSI|UART_IER_RDI|UART_IER_RTOIE|UART_IER_UUE;
6e418a9d
NP		 628 port->mctrl = TIOCM_OUT2;
629
adc8d746 630 sdio_uart_change_speed(port, &tty->termios, NULL);
6e418a9d 631
9db276f8 632 if (C_BAUD(tty))
6e418a9d
NP		 633 sdio_uart_set_mctrl(port, TIOCM_RTS | TIOCM_DTR);
634
9db276f8 635 if (C_CRTSCTS(tty))
6e418a9d 636 if (!(sdio_uart_get_mctrl(port) & TIOCM_CTS))
b5849b1a 637 tty->hw_stopped = 1;
6e418a9d 638
0395b48c 639 clear_bit(TTY_IO_ERROR, &tty->flags);
6e418a9d
NP		 640
641 /* Kick the IRQ handler once while we're still holding the host lock */
642 sdio_uart_irq(port->func);
643
644 sdio_uart_release_func(port);
645 return 0;
646
6e418a9d 647err2:
8b197a5c 648 sdio_disable_func(port->func);
6e418a9d 649err1:
8b197a5c 650 sdio_uart_release_func(port);
6e418a9d
NP		 651 return ret;
652}
653
584abc37
AC		 654/**
655 * sdio_uart_shutdown - stop hardware
656 * @tport: tty port to shut down
657 *
658 * Deactivate a tty port. The port locking guarantees us this will be
659 * run only if a successful matching activate already ran. The two are
660 * protected from each other by the internal locking and will not run
661 * at the same time even during a hangup event.
662 */
663
664static void sdio_uart_shutdown(struct tty_port *tport)
6e418a9d 665{
584abc37
AC		 666 struct sdio_uart_port *port =
667 container_of(tport, struct sdio_uart_port, port);
6e418a9d
NP		 668 int ret;
669
670 ret = sdio_uart_claim_func(port);
671 if (ret)
8b197a5c 672 return;
6e418a9d
NP		 673
674 sdio_uart_stop_rx(port);
675
1e04b7ae 676 /* Disable interrupts from this port */
6e418a9d
NP		 677 sdio_release_irq(port->func);
678 port->ier = 0;
679 sdio_out(port, UART_IER, 0);
680
681 sdio_uart_clear_mctrl(port, TIOCM_OUT2);
682
683 /* Disable break condition and FIFOs. */
684 port->lcr &= ~UART_LCR_SBC;
685 sdio_out(port, UART_LCR, port->lcr);
686 sdio_out(port, UART_FCR, UART_FCR_ENABLE_FIFO |
687 UART_FCR_CLEAR_RCVR |
688 UART_FCR_CLEAR_XMIT);
689 sdio_out(port, UART_FCR, 0);
690
691 sdio_disable_func(port->func);
692
693 sdio_uart_release_func(port);
6e418a9d
NP		 694}
695
e70c6771
JS		 696static void sdio_uart_port_destroy(struct tty_port *tport)
697{
698 struct sdio_uart_port *port =
699 container_of(tport, struct sdio_uart_port, port);
700 kfifo_free(&port->xmit_fifo);
701 kfree(port);
702}
703
584abc37
AC		 704/**
705 * sdio_uart_install - install method
706 * @driver: the driver in use (sdio_uart in our case)
707 * @tty: the tty being bound
708 *
709 * Look up and bind the tty and the driver together. Initialize
710 * any needed private data (in our case the termios)
711 */
6e418a9d 712
584abc37
AC		 713static int sdio_uart_install(struct tty_driver *driver, struct tty_struct *tty)
714{
715 int idx = tty->index;
716 struct sdio_uart_port *port = sdio_uart_port_get(idx);
81f5835e 717 int ret = tty_standard_install(driver, tty);
584abc37 718
81f5835e 719 if (ret == 0)
584abc37
AC		 720 /* This is the ref sdio_uart_port get provided */
721 tty->driver_data = port;
81f5835e 722 else
6e418a9d 723 sdio_uart_port_put(port);
584abc37 724 return ret;
6e418a9d
NP		 725}
726
584abc37
AC		 727/**
728 * sdio_uart_cleanup - called on the last tty kref drop
729 * @tty: the tty being destroyed
730 *
731 * Called asynchronously when the last reference to the tty is dropped.
732 * We cannot destroy the tty->driver_data port kref until this point
733 */
734
735static void sdio_uart_cleanup(struct tty_struct *tty)
6e418a9d
NP		 736{
737 struct sdio_uart_port *port = tty->driver_data;
584abc37
AC		 738 tty->driver_data = NULL; /* Bug trap */
739 sdio_uart_port_put(port);
740}
6e418a9d 741
584abc37
AC		 742/*
743 * Open/close/hangup is now entirely boilerplate
744 */
6e418a9d 745
584abc37
AC		 746static int sdio_uart_open(struct tty_struct *tty, struct file *filp)
747{
748 struct sdio_uart_port *port = tty->driver_data;
749 return tty_port_open(&port->port, tty, filp);
750}
6e418a9d 751
584abc37
AC		 752static void sdio_uart_close(struct tty_struct *tty, struct file * filp)
753{
754 struct sdio_uart_port *port = tty->driver_data;
755 tty_port_close(&port->port, tty, filp);
756}
6e418a9d 757
584abc37
AC		 758static void sdio_uart_hangup(struct tty_struct *tty)
759{
760 struct sdio_uart_port *port = tty->driver_data;
761 tty_port_hangup(&port->port);
6e418a9d
NP		 762}
763
c271cf37 764static int sdio_uart_write(struct tty_struct *tty, const unsigned char *buf,
6e418a9d
NP		 765 int count)
766{
767 struct sdio_uart_port *port = tty->driver_data;
8b197a5c 768 int ret;
6e418a9d
NP		 769
770 if (!port->func)
771 return -ENODEV;
772
8b197a5c 773 ret = kfifo_in_locked(&port->xmit_fifo, buf, count, &port->write_lock);
c271cf37 774 if (!(port->ier & UART_IER_THRI)) {
6e418a9d
NP		 775 int err = sdio_uart_claim_func(port);
776 if (!err) {
777 sdio_uart_start_tx(port);
778 sdio_uart_irq(port->func);
779 sdio_uart_release_func(port);
780 } else
781 ret = err;
782 }
783
784 return ret;
785}
786
03b3b1a2 787static unsigned int sdio_uart_write_room(struct tty_struct *tty)
6e418a9d
NP		 788{
789 struct sdio_uart_port *port = tty->driver_data;
8b197a5c 790 return FIFO_SIZE - kfifo_len(&port->xmit_fifo);
6e418a9d
NP		 791}
792
fff4ef17 793static unsigned int sdio_uart_chars_in_buffer(struct tty_struct *tty)
6e418a9d
NP		 794{
795 struct sdio_uart_port *port = tty->driver_data;
8b197a5c 796 return kfifo_len(&port->xmit_fifo);
6e418a9d
NP		 797}
798
799static void sdio_uart_send_xchar(struct tty_struct *tty, char ch)
800{
801 struct sdio_uart_port *port = tty->driver_data;
802
803 port->x_char = ch;
804 if (ch && !(port->ier & UART_IER_THRI)) {
805 if (sdio_uart_claim_func(port) != 0)
806 return;
807 sdio_uart_start_tx(port);
808 sdio_uart_irq(port->func);
809 sdio_uart_release_func(port);
810 }
811}
812
813static void sdio_uart_throttle(struct tty_struct *tty)
814{
815 struct sdio_uart_port *port = tty->driver_data;
816
9db276f8 817 if (!I_IXOFF(tty) && !C_CRTSCTS(tty))
6e418a9d
NP		 818 return;
819
820 if (sdio_uart_claim_func(port) != 0)
821 return;
822
823 if (I_IXOFF(tty)) {
824 port->x_char = STOP_CHAR(tty);
825 sdio_uart_start_tx(port);
826 }
827
9db276f8 828 if (C_CRTSCTS(tty))
6e418a9d
NP		 829 sdio_uart_clear_mctrl(port, TIOCM_RTS);
830
831 sdio_uart_irq(port->func);
832 sdio_uart_release_func(port);
833}
834
835static void sdio_uart_unthrottle(struct tty_struct *tty)
836{
837 struct sdio_uart_port *port = tty->driver_data;
838
9db276f8 839 if (!I_IXOFF(tty) && !C_CRTSCTS(tty))
6e418a9d
NP		 840 return;
841
842 if (sdio_uart_claim_func(port) != 0)
843 return;
844
845 if (I_IXOFF(tty)) {
846 if (port->x_char) {
847 port->x_char = 0;
848 } else {
849 port->x_char = START_CHAR(tty);
850 sdio_uart_start_tx(port);
851 }
852 }
853
9db276f8 854 if (C_CRTSCTS(tty))
6e418a9d
NP		 855 sdio_uart_set_mctrl(port, TIOCM_RTS);
856
857 sdio_uart_irq(port->func);
858 sdio_uart_release_func(port);
859}
860
c271cf37 861static void sdio_uart_set_termios(struct tty_struct *tty,
a8c11c15 862 const struct ktermios *old_termios)
6e418a9d
NP		 863{
864 struct sdio_uart_port *port = tty->driver_data;
adc8d746 865 unsigned int cflag = tty->termios.c_cflag;
6e418a9d 866
6e418a9d
NP		 867 if (sdio_uart_claim_func(port) != 0)
868 return;
869
adc8d746 870 sdio_uart_change_speed(port, &tty->termios, old_termios);
6e418a9d
NP		 871
872 /* Handle transition to B0 status */
873 if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
874 sdio_uart_clear_mctrl(port, TIOCM_RTS | TIOCM_DTR);
875
876 /* Handle transition away from B0 status */
877 if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
878 unsigned int mask = TIOCM_DTR;
97ef38b8 879 if (!(cflag & CRTSCTS) || !tty_throttled(tty))
6e418a9d
NP		 880 mask |= TIOCM_RTS;
881 sdio_uart_set_mctrl(port, mask);
882 }
883
884 /* Handle turning off CRTSCTS */
885 if ((old_termios->c_cflag & CRTSCTS) && !(cflag & CRTSCTS)) {
886 tty->hw_stopped = 0;
887 sdio_uart_start_tx(port);
888 }
889
890 /* Handle turning on CRTSCTS */
891 if (!(old_termios->c_cflag & CRTSCTS) && (cflag & CRTSCTS)) {
892 if (!(sdio_uart_get_mctrl(port) & TIOCM_CTS)) {
893 tty->hw_stopped = 1;
894 sdio_uart_stop_tx(port);
895 }
896 }
897
898 sdio_uart_release_func(port);
899}
900
c43d8636 901static int sdio_uart_break_ctl(struct tty_struct *tty, int break_state)
6e418a9d
NP		 902{
903 struct sdio_uart_port *port = tty->driver_data;
c43d8636 904 int result;
6e418a9d 905
c43d8636
DH		 906 result = sdio_uart_claim_func(port);
907 if (result != 0)
908 return result;
6e418a9d
NP		 909
910 if (break_state == -1)
911 port->lcr |= UART_LCR_SBC;
912 else
913 port->lcr &= ~UART_LCR_SBC;
914 sdio_out(port, UART_LCR, port->lcr);
915
916 sdio_uart_release_func(port);
c43d8636 917 return 0;
6e418a9d
NP		 918}
919
60b33c13 920static int sdio_uart_tiocmget(struct tty_struct *tty)
6e418a9d
NP		 921{
922 struct sdio_uart_port *port = tty->driver_data;
923 int result;
924
925 result = sdio_uart_claim_func(port);
926 if (!result) {
927 result = port->mctrl | sdio_uart_get_mctrl(port);
928 sdio_uart_release_func(port);
929 }
930
931 return result;
932}
933
20b9d177 934static int sdio_uart_tiocmset(struct tty_struct *tty,
6e418a9d
NP		 935 unsigned int set, unsigned int clear)
936{
937 struct sdio_uart_port *port = tty->driver_data;
938 int result;
939
1e04b7ae 940 result = sdio_uart_claim_func(port);
c271cf37 941 if (!result) {
6e418a9d
NP		 942 sdio_uart_update_mctrl(port, set, clear);
943 sdio_uart_release_func(port);
944 }
945
946 return result;
947}
948
201a50ba 949static int sdio_uart_proc_show(struct seq_file *m, void *v)
5ed334a1 950{
201a50ba 951 int i;
5ed334a1 952
201a50ba 953 seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n",
5ed334a1 954 "", "", "");
201a50ba 955 for (i = 0; i < UART_NR; i++) {
5ed334a1
NP		 956 struct sdio_uart_port *port = sdio_uart_port_get(i);
957 if (port) {
201a50ba 958 seq_printf(m, "%d: uart:SDIO", i);
c271cf37 959 if (capable(CAP_SYS_ADMIN)) {
201a50ba 960 seq_printf(m, " tx:%d rx:%d",
1e04b7ae 961 port->icount.tx, port->icount.rx);
5ed334a1 962 if (port->icount.frame)
201a50ba 963 seq_printf(m, " fe:%d",
1e04b7ae 964 port->icount.frame);
5ed334a1 965 if (port->icount.parity)
201a50ba 966 seq_printf(m, " pe:%d",
1e04b7ae 967 port->icount.parity);
5ed334a1 968 if (port->icount.brk)
201a50ba 969 seq_printf(m, " brk:%d",
1e04b7ae 970 port->icount.brk);
5ed334a1 971 if (port->icount.overrun)
201a50ba 972 seq_printf(m, " oe:%d",
1e04b7ae 973 port->icount.overrun);
5ed334a1 974 if (port->icount.cts)
201a50ba 975 seq_printf(m, " cts:%d",
1e04b7ae 976 port->icount.cts);
5ed334a1 977 if (port->icount.dsr)
201a50ba 978 seq_printf(m, " dsr:%d",
1e04b7ae 979 port->icount.dsr);
5ed334a1 980 if (port->icount.rng)
201a50ba 981 seq_printf(m, " rng:%d",
1e04b7ae 982 port->icount.rng);
5ed334a1 983 if (port->icount.dcd)
201a50ba 984 seq_printf(m, " dcd:%d",
1e04b7ae 985 port->icount.dcd);
5ed334a1 986 }
5ed334a1 987 sdio_uart_port_put(port);
201a50ba 988 seq_putc(m, '\n');
5ed334a1
NP		 989 }
990 }
201a50ba
AD		 991 return 0;
992}
5ed334a1 993
584abc37
AC		 994static const struct tty_port_operations sdio_uart_port_ops = {
995 .dtr_rts = uart_dtr_rts,
4b3b49bb 996 .carrier_raised = uart_carrier_raised,
584abc37
AC		 997 .shutdown = sdio_uart_shutdown,
998 .activate = sdio_uart_activate,
e70c6771 999 .destruct = sdio_uart_port_destroy,
584abc37
AC		 1000};
1001
6e418a9d
NP		 1002static const struct tty_operations sdio_uart_ops = {
1003 .open = sdio_uart_open,
1004 .close = sdio_uart_close,
1005 .write = sdio_uart_write,
1006 .write_room = sdio_uart_write_room,
1007 .chars_in_buffer = sdio_uart_chars_in_buffer,
1008 .send_xchar = sdio_uart_send_xchar,
1009 .throttle = sdio_uart_throttle,
1010 .unthrottle = sdio_uart_unthrottle,
1011 .set_termios = sdio_uart_set_termios,
584abc37 1012 .hangup = sdio_uart_hangup,
6e418a9d
NP		 1013 .break_ctl = sdio_uart_break_ctl,
1014 .tiocmget = sdio_uart_tiocmget,
1015 .tiocmset = sdio_uart_tiocmset,
584abc37
AC		 1016 .install = sdio_uart_install,
1017 .cleanup = sdio_uart_cleanup,
8a8dcabf 1018 .proc_show = sdio_uart_proc_show,
6e418a9d
NP		 1019};
1020
1021static struct tty_driver *sdio_uart_tty_driver;
1022
1023static int sdio_uart_probe(struct sdio_func *func,
1024 const struct sdio_device_id *id)
1025{
1026 struct sdio_uart_port *port;
1027 int ret;
1028
1029 port = kzalloc(sizeof(struct sdio_uart_port), GFP_KERNEL);
1030 if (!port)
1031 return -ENOMEM;
1032
1033 if (func->class == SDIO_CLASS_UART) {
6606110d
JP		 1034 pr_warn("%s: need info on UART class basic setup\n",
1035 sdio_func_id(func));
6e418a9d
NP		 1036 kfree(port);
1037 return -ENOSYS;
1038 } else if (func->class == SDIO_CLASS_GPS) {
1039 /*
1040 * We need tuple 0x91. It contains SUBTPL_SIOREG
1041 * and SUBTPL_RCVCAPS.
1042 */
1043 struct sdio_func_tuple *tpl;
1044 for (tpl = func->tuples; tpl; tpl = tpl->next) {
1045 if (tpl->code != 0x91)
1046 continue;
1047 if (tpl->size < 10)
1048 continue;
1049 if (tpl->data[1] == 0) /* SUBTPL_SIOREG */
1050 break;
1051 }
1052 if (!tpl) {
6606110d
JP		 1053 pr_warn("%s: can't find tuple 0x91 subtuple 0 (SUBTPL_SIOREG) for GPS class\n",
1054 sdio_func_id(func));
6e418a9d
NP		 1055 kfree(port);
1056 return -EINVAL;
1057 }
a3c76eb9 1058 pr_debug("%s: Register ID = 0x%02x, Exp ID = 0x%02x\n",
6e418a9d
NP		 1059 sdio_func_id(func), tpl->data[2], tpl->data[3]);
1060 port->regs_offset = (tpl->data[4] << 0) |
1061 (tpl->data[5] << 8) |
1062 (tpl->data[6] << 16);
a3c76eb9 1063 pr_debug("%s: regs offset = 0x%x\n",
6e418a9d
NP		 1064 sdio_func_id(func), port->regs_offset);
1065 port->uartclk = tpl->data[7] * 115200;
1066 if (port->uartclk == 0)
1067 port->uartclk = 115200;
a3c76eb9 1068 pr_debug("%s: clk %d baudcode %u 4800-div %u\n",
6e418a9d
NP		 1069 sdio_func_id(func), port->uartclk,
1070 tpl->data[7], tpl->data[8] | (tpl->data[9] << 8));
1071 } else {
1072 kfree(port);
1073 return -EINVAL;
1074 }
1075
1076 port->func = func;
1077 sdio_set_drvdata(func, port);
b5849b1a 1078 tty_port_init(&port->port);
584abc37 1079 port->port.ops = &sdio_uart_port_ops;
6e418a9d
NP		 1080
1081 ret = sdio_uart_add_port(port);
1082 if (ret) {
1083 kfree(port);
1084 } else {
1085 struct device *dev;
734cc178
JS		 1086 dev = tty_port_register_device(&port->port,
1087 sdio_uart_tty_driver, port->index, &func->dev);
6e418a9d
NP		 1088 if (IS_ERR(dev)) {
1089 sdio_uart_port_remove(port);
1090 ret = PTR_ERR(dev);
1091 }
1092 }
1093
1094 return ret;
1095}
1096
1097static void sdio_uart_remove(struct sdio_func *func)
1098{
1099 struct sdio_uart_port *port = sdio_get_drvdata(func);
1100
1101 tty_unregister_device(sdio_uart_tty_driver, port->index);
1102 sdio_uart_port_remove(port);
1103}
1104
1105static const struct sdio_device_id sdio_uart_ids[] = {
1106 { SDIO_DEVICE_CLASS(SDIO_CLASS_UART) },
1107 { SDIO_DEVICE_CLASS(SDIO_CLASS_GPS) },
1108 { /* end: all zeroes */ },
1109};
1110
1111MODULE_DEVICE_TABLE(sdio, sdio_uart_ids);
1112
1113static struct sdio_driver sdio_uart_driver = {
1114 .probe = sdio_uart_probe,
1115 .remove = sdio_uart_remove,
1116 .name = "sdio_uart",
1117 .id_table = sdio_uart_ids,
1118};
1119
1120static int __init sdio_uart_init(void)
1121{
1122 int ret;
1123 struct tty_driver *tty_drv;
1124
39b7b42b
JS		 1125 sdio_uart_tty_driver = tty_drv = tty_alloc_driver(UART_NR,
1126 TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV);
1127 if (IS_ERR(tty_drv))
1128 return PTR_ERR(tty_drv);
6e418a9d 1129
6e418a9d
NP		 1130 tty_drv->driver_name = "sdio_uart";
1131 tty_drv->name = "ttySDIO";
1132 tty_drv->major = 0; /* dynamically allocated */
1133 tty_drv->minor_start = 0;
1134 tty_drv->type = TTY_DRIVER_TYPE_SERIAL;
1135 tty_drv->subtype = SERIAL_TYPE_NORMAL;
6e418a9d
NP		 1136 tty_drv->init_termios = tty_std_termios;
1137 tty_drv->init_termios.c_cflag = B4800 | CS8 | CREAD | HUPCL | CLOCAL;
2ba30eed
NP		 1138 tty_drv->init_termios.c_ispeed = 4800;
1139 tty_drv->init_termios.c_ospeed = 4800;
6e418a9d
NP		 1140 tty_set_operations(tty_drv, &sdio_uart_ops);
1141
1142 ret = tty_register_driver(tty_drv);
1143 if (ret)
1144 goto err1;
1145
1146 ret = sdio_register_driver(&sdio_uart_driver);
1147 if (ret)
1148 goto err2;
1149
1150 return 0;
1151
1152err2:
1153 tty_unregister_driver(tty_drv);
1154err1:
9f90a4dd 1155 tty_driver_kref_put(tty_drv);
6e418a9d
NP		 1156 return ret;
1157}
1158
1159static void __exit sdio_uart_exit(void)
1160{
1161 sdio_unregister_driver(&sdio_uart_driver);
1162 tty_unregister_driver(sdio_uart_tty_driver);
9f90a4dd 1163 tty_driver_kref_put(sdio_uart_tty_driver);
6e418a9d
NP		 1164}
1165
1166module_init(sdio_uart_init);
1167module_exit(sdio_uart_exit);
1168
1169MODULE_AUTHOR("Nicolas Pitre");
1170MODULE_LICENSE("GPL");
Linux 6.x block layer and io_uring tree(s)