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Merge branch 'for-linus-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/mason...
[deliverable/linux.git] / drivers / tty / serial / vt8500_serial.c
CommitLineData
304e1266 1/*
304e1266
AC		 2 * Copyright (C) 2010 Alexey Charkov <alchark@gmail.com>
3 *
4 * Based on msm_serial.c, which is:
5 * Copyright (C) 2007 Google, Inc.
6 * Author: Robert Love <rlove@google.com>
7 *
8 * This software is licensed under the terms of the GNU General Public
9 * License version 2, as published by the Free Software Foundation, and
10 * may be copied, distributed, and modified under those terms.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 */
17
18#if defined(CONFIG_SERIAL_VT8500_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
19# define SUPPORT_SYSRQ
20#endif
21
22#include <linux/hrtimer.h>
23#include <linux/delay.h>
24#include <linux/module.h>
25#include <linux/io.h>
26#include <linux/ioport.h>
27#include <linux/irq.h>
28#include <linux/init.h>
29#include <linux/console.h>
30#include <linux/tty.h>
31#include <linux/tty_flip.h>
32#include <linux/serial_core.h>
33#include <linux/serial.h>
34#include <linux/slab.h>
35#include <linux/clk.h>
4001130d 36#include <linux/of.h>
ae382735 37#include <linux/of_device.h>
82b23132 38#include <linux/err.h>
304e1266
AC		 39
40/*
41 * UART Register offsets
42 */
43
44#define VT8500_URTDR 0x0000 /* Transmit data */
45#define VT8500_URRDR 0x0004 /* Receive data */
46#define VT8500_URDIV 0x0008 /* Clock/Baud rate divisor */
47#define VT8500_URLCR 0x000C /* Line control */
48#define VT8500_URICR 0x0010 /* IrDA control */
49#define VT8500_URIER 0x0014 /* Interrupt enable */
50#define VT8500_URISR 0x0018 /* Interrupt status */
51#define VT8500_URUSR 0x001c /* UART status */
52#define VT8500_URFCR 0x0020 /* FIFO control */
53#define VT8500_URFIDX 0x0024 /* FIFO index */
54#define VT8500_URBKR 0x0028 /* Break signal count */
55#define VT8500_URTOD 0x002c /* Time out divisor */
56#define VT8500_TXFIFO 0x1000 /* Transmit FIFO (16x8) */
57#define VT8500_RXFIFO 0x1020 /* Receive FIFO (16x10) */
58
59/*
60 * Interrupt enable and status bits
61 */
62
63#define TXDE (1 << 0) /* Tx Data empty */
64#define RXDF (1 << 1) /* Rx Data full */
65#define TXFAE (1 << 2) /* Tx FIFO almost empty */
66#define TXFE (1 << 3) /* Tx FIFO empty */
67#define RXFAF (1 << 4) /* Rx FIFO almost full */
68#define RXFF (1 << 5) /* Rx FIFO full */
69#define TXUDR (1 << 6) /* Tx underrun */
70#define RXOVER (1 << 7) /* Rx overrun */
71#define PER (1 << 8) /* Parity error */
72#define FER (1 << 9) /* Frame error */
73#define TCTS (1 << 10) /* Toggle of CTS */
74#define RXTOUT (1 << 11) /* Rx timeout */
75#define BKDONE (1 << 12) /* Break signal done */
76#define ERR (1 << 13) /* AHB error response */
77
78#define RX_FIFO_INTS (RXFAF | RXFF | RXOVER | PER | FER | RXTOUT)
79#define TX_FIFO_INTS (TXFAE | TXFE | TXUDR)
80
ae382735
AC		 81/*
82 * Line control bits
83 */
84
85#define VT8500_TXEN (1 << 0) /* Enable transmit logic */
86#define VT8500_RXEN (1 << 1) /* Enable receive logic */
87#define VT8500_CS8 (1 << 2) /* 8-bit data length (vs. 7-bit) */
88#define VT8500_CSTOPB (1 << 3) /* 2 stop bits (vs. 1) */
89#define VT8500_PARENB (1 << 4) /* Enable parity */
90#define VT8500_PARODD (1 << 5) /* Odd parity (vs. even) */
91#define VT8500_RTS (1 << 6) /* Ready to send */
92#define VT8500_LOOPBK (1 << 7) /* Enable internal loopback */
93#define VT8500_DMA (1 << 8) /* Enable DMA mode (needs FIFO) */
94#define VT8500_BREAK (1 << 9) /* Initiate break signal */
95#define VT8500_PSLVERR (1 << 10) /* APB error upon empty RX FIFO read */
96#define VT8500_SWRTSCTS (1 << 11) /* Software-controlled RTS/CTS */
97
98/*
99 * Capability flags (driver-internal)
100 */
101
102#define VT8500_HAS_SWRTSCTS_SWITCH (1 << 1)
103
5aa387c1
AC		 104#define VT8500_RECOMMENDED_CLK 12000000
105#define VT8500_OVERSAMPLING_DIVISOR 13
4001130d
TP		 106#define VT8500_MAX_PORTS 6
107
304e1266
AC		 108struct vt8500_port {
109 struct uart_port uart;
110 char name[16];
111 struct clk *clk;
5aa387c1 112 unsigned int clk_predivisor;
304e1266 113 unsigned int ier;
ae382735 114 unsigned int vt8500_uart_flags;
304e1266
AC		 115};
116
4001130d
TP		 117/*
118 * we use this variable to keep track of which ports
119 * have been allocated as we can't use pdev->id in
120 * devicetree
121 */
122static unsigned long vt8500_ports_in_use;
123
304e1266
AC		 124static inline void vt8500_write(struct uart_port *port, unsigned int val,
125 unsigned int off)
126{
127 writel(val, port->membase + off);
128}
129
130static inline unsigned int vt8500_read(struct uart_port *port, unsigned int off)
131{
132 return readl(port->membase + off);
133}
134
135static void vt8500_stop_tx(struct uart_port *port)
136{
137 struct vt8500_port *vt8500_port = container_of(port,
138 struct vt8500_port,
139 uart);
140
141 vt8500_port->ier &= ~TX_FIFO_INTS;
142 vt8500_write(port, vt8500_port->ier, VT8500_URIER);
143}
144
145static void vt8500_stop_rx(struct uart_port *port)
146{
147 struct vt8500_port *vt8500_port = container_of(port,
148 struct vt8500_port,
149 uart);
150
151 vt8500_port->ier &= ~RX_FIFO_INTS;
152 vt8500_write(port, vt8500_port->ier, VT8500_URIER);
153}
154
155static void vt8500_enable_ms(struct uart_port *port)
156{
157 struct vt8500_port *vt8500_port = container_of(port,
158 struct vt8500_port,
159 uart);
160
161 vt8500_port->ier |= TCTS;
162 vt8500_write(port, vt8500_port->ier, VT8500_URIER);
163}
164
165static void handle_rx(struct uart_port *port)
166{
92a19f9c 167 struct tty_port *tport = &port->state->port;
304e1266
AC		 168
169 /*
170 * Handle overrun
171 */
172 if ((vt8500_read(port, VT8500_URISR) & RXOVER)) {
173 port->icount.overrun++;
92a19f9c 174 tty_insert_flip_char(tport, 0, TTY_OVERRUN);
304e1266
AC		 175 }
176
177 /* and now the main RX loop */
178 while (vt8500_read(port, VT8500_URFIDX) & 0x1f00) {
179 unsigned int c;
180 char flag = TTY_NORMAL;
181
182 c = readw(port->membase + VT8500_RXFIFO) & 0x3ff;
183
184 /* Mask conditions we're ignorning. */
185 c &= ~port->read_status_mask;
186
187 if (c & FER) {
188 port->icount.frame++;
189 flag = TTY_FRAME;
190 } else if (c & PER) {
191 port->icount.parity++;
192 flag = TTY_PARITY;
193 }
194 port->icount.rx++;
195
196 if (!uart_handle_sysrq_char(port, c))
92a19f9c 197 tty_insert_flip_char(tport, c, flag);
304e1266
AC		 198 }
199
de49df58 200 spin_unlock(&port->lock);
2e124b4a 201 tty_flip_buffer_push(tport);
de49df58 202 spin_lock(&port->lock);
304e1266
AC		 203}
204
205static void handle_tx(struct uart_port *port)
206{
207 struct circ_buf *xmit = &port->state->xmit;
208
209 if (port->x_char) {
210 writeb(port->x_char, port->membase + VT8500_TXFIFO);
211 port->icount.tx++;
212 port->x_char = 0;
213 }
214 if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
215 vt8500_stop_tx(port);
216 return;
217 }
218
219 while ((vt8500_read(port, VT8500_URFIDX) & 0x1f) < 16) {
220 if (uart_circ_empty(xmit))
221 break;
222
223 writeb(xmit->buf[xmit->tail], port->membase + VT8500_TXFIFO);
224
225 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
226 port->icount.tx++;
227 }
228
229 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
230 uart_write_wakeup(port);
231
232 if (uart_circ_empty(xmit))
233 vt8500_stop_tx(port);
234}
235
236static void vt8500_start_tx(struct uart_port *port)
237{
238 struct vt8500_port *vt8500_port = container_of(port,
239 struct vt8500_port,
240 uart);
241
242 vt8500_port->ier &= ~TX_FIFO_INTS;
243 vt8500_write(port, vt8500_port->ier, VT8500_URIER);
244 handle_tx(port);
245 vt8500_port->ier |= TX_FIFO_INTS;
246 vt8500_write(port, vt8500_port->ier, VT8500_URIER);
247}
248
249static void handle_delta_cts(struct uart_port *port)
250{
251 port->icount.cts++;
252 wake_up_interruptible(&port->state->port.delta_msr_wait);
253}
254
255static irqreturn_t vt8500_irq(int irq, void *dev_id)
256{
257 struct uart_port *port = dev_id;
258 unsigned long isr;
259
260 spin_lock(&port->lock);
261 isr = vt8500_read(port, VT8500_URISR);
262
263 /* Acknowledge active status bits */
264 vt8500_write(port, isr, VT8500_URISR);
265
266 if (isr & RX_FIFO_INTS)
267 handle_rx(port);
268 if (isr & TX_FIFO_INTS)
269 handle_tx(port);
270 if (isr & TCTS)
271 handle_delta_cts(port);
272
273 spin_unlock(&port->lock);
274
275 return IRQ_HANDLED;
276}
277
278static unsigned int vt8500_tx_empty(struct uart_port *port)
279{
280 return (vt8500_read(port, VT8500_URFIDX) & 0x1f) < 16 ?
281 TIOCSER_TEMT : 0;
282}
283
284static unsigned int vt8500_get_mctrl(struct uart_port *port)
285{
286 unsigned int usr;
287
288 usr = vt8500_read(port, VT8500_URUSR);
289 if (usr & (1 << 4))
290 return TIOCM_CTS;
291 else
292 return 0;
293}
294
295static void vt8500_set_mctrl(struct uart_port *port, unsigned int mctrl)
296{
8c986d3e
AC		 297 unsigned int lcr = vt8500_read(port, VT8500_URLCR);
298
299 if (mctrl & TIOCM_RTS)
300 lcr |= VT8500_RTS;
301 else
302 lcr &= ~VT8500_RTS;
303
304 vt8500_write(port, lcr, VT8500_URLCR);
304e1266
AC		 305}
306
307static void vt8500_break_ctl(struct uart_port *port, int break_ctl)
308{
309 if (break_ctl)
ae382735
AC		 310 vt8500_write(port,
311 vt8500_read(port, VT8500_URLCR) | VT8500_BREAK,
304e1266
AC		 312 VT8500_URLCR);
313}
314
315static int vt8500_set_baud_rate(struct uart_port *port, unsigned int baud)
316{
5aa387c1
AC		 317 struct vt8500_port *vt8500_port =
318 container_of(port, struct vt8500_port, uart);
304e1266
AC		 319 unsigned long div;
320 unsigned int loops = 1000;
321
5aa387c1
AC		 322 div = ((vt8500_port->clk_predivisor - 1) & 0xf) << 16;
323 div |= (uart_get_divisor(port, baud) - 1) & 0x3ff;
304e1266 324
5aa387c1
AC		 325 /* Effective baud rate */
326 baud = port->uartclk / 16 / ((div & 0x3ff) + 1);
304e1266
AC		 327
328 while ((vt8500_read(port, VT8500_URUSR) & (1 << 5)) && --loops)
329 cpu_relax();
5aa387c1 330
304e1266
AC		 331 vt8500_write(port, div, VT8500_URDIV);
332
5aa387c1
AC		 333 /* Break signal timing depends on baud rate, update accordingly */
334 vt8500_write(port, mult_frac(baud, 4096, 1000000), VT8500_URBKR);
335
304e1266
AC		 336 return baud;
337}
338
339static int vt8500_startup(struct uart_port *port)
340{
341 struct vt8500_port *vt8500_port =
342 container_of(port, struct vt8500_port, uart);
343 int ret;
344
345 snprintf(vt8500_port->name, sizeof(vt8500_port->name),
346 "vt8500_serial%d", port->line);
347
348 ret = request_irq(port->irq, vt8500_irq, IRQF_TRIGGER_HIGH,
349 vt8500_port->name, port);
350 if (unlikely(ret))
351 return ret;
352
353 vt8500_write(port, 0x03, VT8500_URLCR); /* enable TX & RX */
354
355 return 0;
356}
357
358static void vt8500_shutdown(struct uart_port *port)
359{
360 struct vt8500_port *vt8500_port =
361 container_of(port, struct vt8500_port, uart);
362
363 vt8500_port->ier = 0;
364
365 /* disable interrupts and FIFOs */
366 vt8500_write(&vt8500_port->uart, 0, VT8500_URIER);
367 vt8500_write(&vt8500_port->uart, 0x880, VT8500_URFCR);
368 free_irq(port->irq, port);
369}
370
371static void vt8500_set_termios(struct uart_port *port,
372 struct ktermios *termios,
373 struct ktermios *old)
374{
375 struct vt8500_port *vt8500_port =
376 container_of(port, struct vt8500_port, uart);
377 unsigned long flags;
378 unsigned int baud, lcr;
379 unsigned int loops = 1000;
380
381 spin_lock_irqsave(&port->lock, flags);
382
383 /* calculate and set baud rate */
384 baud = uart_get_baud_rate(port, termios, old, 900, 921600);
385 baud = vt8500_set_baud_rate(port, baud);
386 if (tty_termios_baud_rate(termios))
387 tty_termios_encode_baud_rate(termios, baud, baud);
388
389 /* calculate parity */
390 lcr = vt8500_read(&vt8500_port->uart, VT8500_URLCR);
ae382735 391 lcr &= ~(VT8500_PARENB | VT8500_PARODD);
304e1266 392 if (termios->c_cflag & PARENB) {
ae382735 393 lcr |= VT8500_PARENB;
304e1266
AC		 394 termios->c_cflag &= ~CMSPAR;
395 if (termios->c_cflag & PARODD)
ae382735 396 lcr |= VT8500_PARODD;
304e1266
AC		 397 }
398
399 /* calculate bits per char */
ae382735 400 lcr &= ~VT8500_CS8;
304e1266
AC		 401 switch (termios->c_cflag & CSIZE) {
402 case CS7:
403 break;
404 case CS8:
405 default:
ae382735 406 lcr |= VT8500_CS8;
304e1266
AC		 407 termios->c_cflag &= ~CSIZE;
408 termios->c_cflag |= CS8;
409 break;
410 }
411
412 /* calculate stop bits */
ae382735 413 lcr &= ~VT8500_CSTOPB;
304e1266 414 if (termios->c_cflag & CSTOPB)
ae382735
AC		 415 lcr |= VT8500_CSTOPB;
416
417 lcr &= ~VT8500_SWRTSCTS;
418 if (vt8500_port->vt8500_uart_flags & VT8500_HAS_SWRTSCTS_SWITCH)
419 lcr |= VT8500_SWRTSCTS;
304e1266
AC		 420
421 /* set parity, bits per char, and stop bit */
422 vt8500_write(&vt8500_port->uart, lcr, VT8500_URLCR);
423
424 /* Configure status bits to ignore based on termio flags. */
425 port->read_status_mask = 0;
426 if (termios->c_iflag & IGNPAR)
427 port->read_status_mask = FER | PER;
428
429 uart_update_timeout(port, termios->c_cflag, baud);
430
431 /* Reset FIFOs */
432 vt8500_write(&vt8500_port->uart, 0x88c, VT8500_URFCR);
433 while ((vt8500_read(&vt8500_port->uart, VT8500_URFCR) & 0xc)
434 && --loops)
435 cpu_relax();
436
437 /* Every possible FIFO-related interrupt */
438 vt8500_port->ier = RX_FIFO_INTS | TX_FIFO_INTS;
439
440 /*
441 * CTS flow control
442 */
443 if (UART_ENABLE_MS(&vt8500_port->uart, termios->c_cflag))
444 vt8500_port->ier |= TCTS;
445
446 vt8500_write(&vt8500_port->uart, 0x881, VT8500_URFCR);
447 vt8500_write(&vt8500_port->uart, vt8500_port->ier, VT8500_URIER);
448
449 spin_unlock_irqrestore(&port->lock, flags);
450}
451
452static const char *vt8500_type(struct uart_port *port)
453{
454 struct vt8500_port *vt8500_port =
455 container_of(port, struct vt8500_port, uart);
456 return vt8500_port->name;
457}
458
459static void vt8500_release_port(struct uart_port *port)
460{
461}
462
463static int vt8500_request_port(struct uart_port *port)
464{
465 return 0;
466}
467
468static void vt8500_config_port(struct uart_port *port, int flags)
469{
470 port->type = PORT_VT8500;
471}
472
473static int vt8500_verify_port(struct uart_port *port,
474 struct serial_struct *ser)
475{
476 if (unlikely(ser->type != PORT_UNKNOWN && ser->type != PORT_VT8500))
477 return -EINVAL;
478 if (unlikely(port->irq != ser->irq))
479 return -EINVAL;
480 return 0;
481}
482
4001130d 483static struct vt8500_port *vt8500_uart_ports[VT8500_MAX_PORTS];
304e1266
AC		 484static struct uart_driver vt8500_uart_driver;
485
486#ifdef CONFIG_SERIAL_VT8500_CONSOLE
487
eba3b47b 488static void wait_for_xmitr(struct uart_port *port)
304e1266
AC		 489{
490 unsigned int status, tmout = 10000;
491
492 /* Wait up to 10ms for the character(s) to be sent. */
493 do {
494 status = vt8500_read(port, VT8500_URFIDX);
495
496 if (--tmout == 0)
497 break;
498 udelay(1);
499 } while (status & 0x10);
500}
501
502static void vt8500_console_putchar(struct uart_port *port, int c)
503{
504 wait_for_xmitr(port);
505 writeb(c, port->membase + VT8500_TXFIFO);
506}
507
508static void vt8500_console_write(struct console *co, const char *s,
509 unsigned int count)
510{
511 struct vt8500_port *vt8500_port = vt8500_uart_ports[co->index];
512 unsigned long ier;
513
514 BUG_ON(co->index < 0 || co->index >= vt8500_uart_driver.nr);
515
516 ier = vt8500_read(&vt8500_port->uart, VT8500_URIER);
517 vt8500_write(&vt8500_port->uart, VT8500_URIER, 0);
518
519 uart_console_write(&vt8500_port->uart, s, count,
520 vt8500_console_putchar);
521
522 /*
523 * Finally, wait for transmitter to become empty
524 * and switch back to FIFO
525 */
526 wait_for_xmitr(&vt8500_port->uart);
527 vt8500_write(&vt8500_port->uart, VT8500_URIER, ier);
528}
529
530static int __init vt8500_console_setup(struct console *co, char *options)
531{
532 struct vt8500_port *vt8500_port;
533 int baud = 9600;
534 int bits = 8;
535 int parity = 'n';
536 int flow = 'n';
537
538 if (unlikely(co->index >= vt8500_uart_driver.nr || co->index < 0))
539 return -ENXIO;
540
541 vt8500_port = vt8500_uart_ports[co->index];
542
543 if (!vt8500_port)
544 return -ENODEV;
545
546 if (options)
547 uart_parse_options(options, &baud, &parity, &bits, &flow);
548
549 return uart_set_options(&vt8500_port->uart,
550 co, baud, parity, bits, flow);
551}
552
553static struct console vt8500_console = {
554 .name = "ttyWMT",
555 .write = vt8500_console_write,
556 .device = uart_console_device,
557 .setup = vt8500_console_setup,
558 .flags = CON_PRINTBUFFER,
559 .index = -1,
560 .data = &vt8500_uart_driver,
561};
562
563#define VT8500_CONSOLE (&vt8500_console)
564
565#else
566#define VT8500_CONSOLE NULL
567#endif
568
1db894ec
AC		 569#ifdef CONFIG_CONSOLE_POLL
570static int vt8500_get_poll_char(struct uart_port *port)
571{
572 unsigned int status = vt8500_read(port, VT8500_URFIDX);
573
574 if (!(status & 0x1f00))
575 return NO_POLL_CHAR;
576
577 return vt8500_read(port, VT8500_RXFIFO) & 0xff;
578}
579
580static void vt8500_put_poll_char(struct uart_port *port, unsigned char c)
581{
582 unsigned int status, tmout = 10000;
583
584 do {
585 status = vt8500_read(port, VT8500_URFIDX);
586
587 if (--tmout == 0)
588 break;
589 udelay(1);
590 } while (status & 0x10);
591
592 vt8500_write(port, c, VT8500_TXFIFO);
593}
594#endif
595
304e1266
AC		 596static struct uart_ops vt8500_uart_pops = {
597 .tx_empty = vt8500_tx_empty,
598 .set_mctrl = vt8500_set_mctrl,
599 .get_mctrl = vt8500_get_mctrl,
600 .stop_tx = vt8500_stop_tx,
601 .start_tx = vt8500_start_tx,
602 .stop_rx = vt8500_stop_rx,
603 .enable_ms = vt8500_enable_ms,
604 .break_ctl = vt8500_break_ctl,
605 .startup = vt8500_startup,
606 .shutdown = vt8500_shutdown,
607 .set_termios = vt8500_set_termios,
608 .type = vt8500_type,
609 .release_port = vt8500_release_port,
610 .request_port = vt8500_request_port,
611 .config_port = vt8500_config_port,
612 .verify_port = vt8500_verify_port,
1db894ec
AC		 613#ifdef CONFIG_CONSOLE_POLL
614 .poll_get_char = vt8500_get_poll_char,
615 .poll_put_char = vt8500_put_poll_char,
616#endif
304e1266
AC		 617};
618
619static struct uart_driver vt8500_uart_driver = {
620 .owner = THIS_MODULE,
621 .driver_name = "vt8500_serial",
622 .dev_name = "ttyWMT",
623 .nr = 6,
624 .cons = VT8500_CONSOLE,
625};
626
ae382735
AC		 627static unsigned int vt8500_flags; /* none required so far */
628static unsigned int wm8880_flags = VT8500_HAS_SWRTSCTS_SWITCH;
629
630static const struct of_device_id wmt_dt_ids[] = {
631 { .compatible = "via,vt8500-uart", .data = &vt8500_flags},
632 { .compatible = "wm,wm8880-uart", .data = &wm8880_flags},
633 {}
634};
635
9671f099 636static int vt8500_serial_probe(struct platform_device *pdev)
304e1266
AC		 637{
638 struct vt8500_port *vt8500_port;
639 struct resource *mmres, *irqres;
4001130d 640 struct device_node *np = pdev->dev.of_node;
ae382735
AC		 641 const struct of_device_id *match;
642 const unsigned int *flags;
304e1266 643 int ret;
4001130d 644 int port;
304e1266 645
ae382735
AC		 646 match = of_match_device(wmt_dt_ids, &pdev->dev);
647 if (!match)
648 return -EINVAL;
649
650 flags = match->data;
651
304e1266
AC		 652 mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
653 irqres = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
654 if (!mmres || !irqres)
655 return -ENODEV;
656
d969de8d 657 if (np) {
4001130d 658 port = of_alias_get_id(np, "serial");
27dd2e04 659 if (port >= VT8500_MAX_PORTS)
4001130d 660 port = -1;
d969de8d 661 } else {
4001130d 662 port = -1;
d969de8d 663 }
4001130d
TP		 664
665 if (port < 0) {
666 /* calculate the port id */
667 port = find_first_zero_bit(&vt8500_ports_in_use,
668 sizeof(vt8500_ports_in_use));
669 }
670
27dd2e04 671 if (port >= VT8500_MAX_PORTS)
4001130d
TP		 672 return -ENODEV;
673
674 /* reserve the port id */
675 if (test_and_set_bit(port, &vt8500_ports_in_use)) {
676 /* port already in use - shouldn't really happen */
677 return -EBUSY;
678 }
679
49abd90c
TP		 680 vt8500_port = devm_kzalloc(&pdev->dev, sizeof(struct vt8500_port),
681 GFP_KERNEL);
59c2e855
WY		 682 if (!vt8500_port)
683 return -ENOMEM;
684
82b23132
SK		 685 vt8500_port->uart.membase = devm_ioremap_resource(&pdev->dev, mmres);
686 if (IS_ERR(vt8500_port->uart.membase))
687 return PTR_ERR(vt8500_port->uart.membase);
12faa35a
TP		 688
689 vt8500_port->clk = of_clk_get(pdev->dev.of_node, 0);
690 if (IS_ERR(vt8500_port->clk)) {
691 dev_err(&pdev->dev, "failed to get clock\n");
49abd90c 692 return -EINVAL;
12faa35a
TP		 693 }
694
695 ret = clk_prepare_enable(vt8500_port->clk);
696 if (ret) {
697 dev_err(&pdev->dev, "failed to enable clock\n");
49abd90c 698 return ret;
12faa35a
TP		 699 }
700
ae382735 701 vt8500_port->vt8500_uart_flags = *flags;
5aa387c1
AC		 702 vt8500_port->clk_predivisor = DIV_ROUND_CLOSEST(
703 clk_get_rate(vt8500_port->clk),
704 VT8500_RECOMMENDED_CLK
705 );
304e1266
AC		 706 vt8500_port->uart.type = PORT_VT8500;
707 vt8500_port->uart.iotype = UPIO_MEM;
708 vt8500_port->uart.mapbase = mmres->start;
709 vt8500_port->uart.irq = irqres->start;
710 vt8500_port->uart.fifosize = 16;
711 vt8500_port->uart.ops = &vt8500_uart_pops;
4001130d 712 vt8500_port->uart.line = port;
304e1266
AC		 713 vt8500_port->uart.dev = &pdev->dev;
714 vt8500_port->uart.flags = UPF_IOREMAP | UPF_BOOT_AUTOCONF;
4001130d 715
5aa387c1
AC		 716 /* Serial core uses the magic "16" everywhere - adjust for it */
717 vt8500_port->uart.uartclk = 16 * clk_get_rate(vt8500_port->clk) /
718 vt8500_port->clk_predivisor /
719 VT8500_OVERSAMPLING_DIVISOR;
304e1266
AC		 720
721 snprintf(vt8500_port->name, sizeof(vt8500_port->name),
722 "VT8500 UART%d", pdev->id);
723
4001130d 724 vt8500_uart_ports[port] = vt8500_port;
304e1266
AC		 725
726 uart_add_one_port(&vt8500_uart_driver, &vt8500_port->uart);
727
728 platform_set_drvdata(pdev, vt8500_port);
729
730 return 0;
304e1266
AC		 731}
732
ae8d8a14 733static int vt8500_serial_remove(struct platform_device *pdev)
304e1266
AC		 734{
735 struct vt8500_port *vt8500_port = platform_get_drvdata(pdev);
736
12faa35a 737 clk_disable_unprepare(vt8500_port->clk);
304e1266 738 uart_remove_one_port(&vt8500_uart_driver, &vt8500_port->uart);
304e1266
AC		 739
740 return 0;
741}
742
743static struct platform_driver vt8500_platform_driver = {
744 .probe = vt8500_serial_probe,
2d47b716 745 .remove = vt8500_serial_remove,
304e1266
AC		 746 .driver = {
747 .name = "vt8500_serial",
86c346de 748 .of_match_table = wmt_dt_ids,
304e1266
AC		 749 },
750};
751
752static int __init vt8500_serial_init(void)
753{
754 int ret;
755
756 ret = uart_register_driver(&vt8500_uart_driver);
757 if (unlikely(ret))
758 return ret;
759
760 ret = platform_driver_register(&vt8500_platform_driver);
761
762 if (unlikely(ret))
763 uart_unregister_driver(&vt8500_uart_driver);
764
765 return ret;
766}
767
768static void __exit vt8500_serial_exit(void)
769{
770#ifdef CONFIG_SERIAL_VT8500_CONSOLE
771 unregister_console(&vt8500_console);
772#endif
773 platform_driver_unregister(&vt8500_platform_driver);
774 uart_unregister_driver(&vt8500_uart_driver);
775}
776
777module_init(vt8500_serial_init);
778module_exit(vt8500_serial_exit);
779
780MODULE_AUTHOR("Alexey Charkov <alchark@gmail.com>");
781MODULE_DESCRIPTION("Driver for vt8500 serial device");
4001130d 782MODULE_LICENSE("GPL v2");
Linux kernel - Deliverables
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