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1/*
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>
36#include <linux/platform_device.h>
37
38/*
39 * UART Register offsets
40 */
41
42#define VT8500_URTDR 0x0000 /* Transmit data */
43#define VT8500_URRDR 0x0004 /* Receive data */
44#define VT8500_URDIV 0x0008 /* Clock/Baud rate divisor */
45#define VT8500_URLCR 0x000C /* Line control */
46#define VT8500_URICR 0x0010 /* IrDA control */
47#define VT8500_URIER 0x0014 /* Interrupt enable */
48#define VT8500_URISR 0x0018 /* Interrupt status */
49#define VT8500_URUSR 0x001c /* UART status */
50#define VT8500_URFCR 0x0020 /* FIFO control */
51#define VT8500_URFIDX 0x0024 /* FIFO index */
52#define VT8500_URBKR 0x0028 /* Break signal count */
53#define VT8500_URTOD 0x002c /* Time out divisor */
54#define VT8500_TXFIFO 0x1000 /* Transmit FIFO (16x8) */
55#define VT8500_RXFIFO 0x1020 /* Receive FIFO (16x10) */
56
57/*
58 * Interrupt enable and status bits
59 */
60
61#define TXDE (1 << 0) /* Tx Data empty */
62#define RXDF (1 << 1) /* Rx Data full */
63#define TXFAE (1 << 2) /* Tx FIFO almost empty */
64#define TXFE (1 << 3) /* Tx FIFO empty */
65#define RXFAF (1 << 4) /* Rx FIFO almost full */
66#define RXFF (1 << 5) /* Rx FIFO full */
67#define TXUDR (1 << 6) /* Tx underrun */
68#define RXOVER (1 << 7) /* Rx overrun */
69#define PER (1 << 8) /* Parity error */
70#define FER (1 << 9) /* Frame error */
71#define TCTS (1 << 10) /* Toggle of CTS */
72#define RXTOUT (1 << 11) /* Rx timeout */
73#define BKDONE (1 << 12) /* Break signal done */
74#define ERR (1 << 13) /* AHB error response */
75
76#define RX_FIFO_INTS (RXFAF | RXFF | RXOVER | PER | FER | RXTOUT)
77#define TX_FIFO_INTS (TXFAE | TXFE | TXUDR)
78
79struct vt8500_port {
80 struct uart_port uart;
81 char name[16];
82 struct clk *clk;
83 unsigned int ier;
84};
85
86static inline void vt8500_write(struct uart_port *port, unsigned int val,
87 unsigned int off)
88{
89 writel(val, port->membase + off);
90}
91
92static inline unsigned int vt8500_read(struct uart_port *port, unsigned int off)
93{
94 return readl(port->membase + off);
95}
96
97static void vt8500_stop_tx(struct uart_port *port)
98{
99 struct vt8500_port *vt8500_port = container_of(port,
100 struct vt8500_port,
101 uart);
102
103 vt8500_port->ier &= ~TX_FIFO_INTS;
104 vt8500_write(port, vt8500_port->ier, VT8500_URIER);
105}
106
107static void vt8500_stop_rx(struct uart_port *port)
108{
109 struct vt8500_port *vt8500_port = container_of(port,
110 struct vt8500_port,
111 uart);
112
113 vt8500_port->ier &= ~RX_FIFO_INTS;
114 vt8500_write(port, vt8500_port->ier, VT8500_URIER);
115}
116
117static void vt8500_enable_ms(struct uart_port *port)
118{
119 struct vt8500_port *vt8500_port = container_of(port,
120 struct vt8500_port,
121 uart);
122
123 vt8500_port->ier |= TCTS;
124 vt8500_write(port, vt8500_port->ier, VT8500_URIER);
125}
126
127static void handle_rx(struct uart_port *port)
128{
129 struct tty_struct *tty = tty_port_tty_get(&port->state->port);
130 if (!tty) {
131 /* Discard data: no tty available */
132 int count = (vt8500_read(port, VT8500_URFIDX) & 0x1f00) >> 8;
133 u16 ch;
134 while (count--)
135 ch = readw(port->membase + VT8500_RXFIFO);
136 return;
137 }
138
139 /*
140 * Handle overrun
141 */
142 if ((vt8500_read(port, VT8500_URISR) & RXOVER)) {
143 port->icount.overrun++;
144 tty_insert_flip_char(tty, 0, TTY_OVERRUN);
145 }
146
147 /* and now the main RX loop */
148 while (vt8500_read(port, VT8500_URFIDX) & 0x1f00) {
149 unsigned int c;
150 char flag = TTY_NORMAL;
151
152 c = readw(port->membase + VT8500_RXFIFO) & 0x3ff;
153
154 /* Mask conditions we're ignorning. */
155 c &= ~port->read_status_mask;
156
157 if (c & FER) {
158 port->icount.frame++;
159 flag = TTY_FRAME;
160 } else if (c & PER) {
161 port->icount.parity++;
162 flag = TTY_PARITY;
163 }
164 port->icount.rx++;
165
166 if (!uart_handle_sysrq_char(port, c))
167 tty_insert_flip_char(tty, c, flag);
168 }
169
170 tty_flip_buffer_push(tty);
171 tty_kref_put(tty);
172}
173
174static void handle_tx(struct uart_port *port)
175{
176 struct circ_buf *xmit = &port->state->xmit;
177
178 if (port->x_char) {
179 writeb(port->x_char, port->membase + VT8500_TXFIFO);
180 port->icount.tx++;
181 port->x_char = 0;
182 }
183 if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
184 vt8500_stop_tx(port);
185 return;
186 }
187
188 while ((vt8500_read(port, VT8500_URFIDX) & 0x1f) < 16) {
189 if (uart_circ_empty(xmit))
190 break;
191
192 writeb(xmit->buf[xmit->tail], port->membase + VT8500_TXFIFO);
193
194 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
195 port->icount.tx++;
196 }
197
198 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
199 uart_write_wakeup(port);
200
201 if (uart_circ_empty(xmit))
202 vt8500_stop_tx(port);
203}
204
205static void vt8500_start_tx(struct uart_port *port)
206{
207 struct vt8500_port *vt8500_port = container_of(port,
208 struct vt8500_port,
209 uart);
210
211 vt8500_port->ier &= ~TX_FIFO_INTS;
212 vt8500_write(port, vt8500_port->ier, VT8500_URIER);
213 handle_tx(port);
214 vt8500_port->ier |= TX_FIFO_INTS;
215 vt8500_write(port, vt8500_port->ier, VT8500_URIER);
216}
217
218static void handle_delta_cts(struct uart_port *port)
219{
220 port->icount.cts++;
221 wake_up_interruptible(&port->state->port.delta_msr_wait);
222}
223
224static irqreturn_t vt8500_irq(int irq, void *dev_id)
225{
226 struct uart_port *port = dev_id;
227 unsigned long isr;
228
229 spin_lock(&port->lock);
230 isr = vt8500_read(port, VT8500_URISR);
231
232 /* Acknowledge active status bits */
233 vt8500_write(port, isr, VT8500_URISR);
234
235 if (isr & RX_FIFO_INTS)
236 handle_rx(port);
237 if (isr & TX_FIFO_INTS)
238 handle_tx(port);
239 if (isr & TCTS)
240 handle_delta_cts(port);
241
242 spin_unlock(&port->lock);
243
244 return IRQ_HANDLED;
245}
246
247static unsigned int vt8500_tx_empty(struct uart_port *port)
248{
249 return (vt8500_read(port, VT8500_URFIDX) & 0x1f) < 16 ?
250 TIOCSER_TEMT : 0;
251}
252
253static unsigned int vt8500_get_mctrl(struct uart_port *port)
254{
255 unsigned int usr;
256
257 usr = vt8500_read(port, VT8500_URUSR);
258 if (usr & (1 << 4))
259 return TIOCM_CTS;
260 else
261 return 0;
262}
263
264static void vt8500_set_mctrl(struct uart_port *port, unsigned int mctrl)
265{
266}
267
268static void vt8500_break_ctl(struct uart_port *port, int break_ctl)
269{
270 if (break_ctl)
271 vt8500_write(port, vt8500_read(port, VT8500_URLCR) | (1 << 9),
272 VT8500_URLCR);
273}
274
275static int vt8500_set_baud_rate(struct uart_port *port, unsigned int baud)
276{
277 unsigned long div;
278 unsigned int loops = 1000;
279
280 div = vt8500_read(port, VT8500_URDIV) & ~(0x3ff);
281
282 if (unlikely((baud < 900) || (baud > 921600)))
283 div |= 7;
284 else
285 div |= (921600 / baud) - 1;
286
287 while ((vt8500_read(port, VT8500_URUSR) & (1 << 5)) && --loops)
288 cpu_relax();
289 vt8500_write(port, div, VT8500_URDIV);
290
291 return baud;
292}
293
294static int vt8500_startup(struct uart_port *port)
295{
296 struct vt8500_port *vt8500_port =
297 container_of(port, struct vt8500_port, uart);
298 int ret;
299
300 snprintf(vt8500_port->name, sizeof(vt8500_port->name),
301 "vt8500_serial%d", port->line);
302
303 ret = request_irq(port->irq, vt8500_irq, IRQF_TRIGGER_HIGH,
304 vt8500_port->name, port);
305 if (unlikely(ret))
306 return ret;
307
308 vt8500_write(port, 0x03, VT8500_URLCR); /* enable TX & RX */
309
310 return 0;
311}
312
313static void vt8500_shutdown(struct uart_port *port)
314{
315 struct vt8500_port *vt8500_port =
316 container_of(port, struct vt8500_port, uart);
317
318 vt8500_port->ier = 0;
319
320 /* disable interrupts and FIFOs */
321 vt8500_write(&vt8500_port->uart, 0, VT8500_URIER);
322 vt8500_write(&vt8500_port->uart, 0x880, VT8500_URFCR);
323 free_irq(port->irq, port);
324}
325
326static void vt8500_set_termios(struct uart_port *port,
327 struct ktermios *termios,
328 struct ktermios *old)
329{
330 struct vt8500_port *vt8500_port =
331 container_of(port, struct vt8500_port, uart);
332 unsigned long flags;
333 unsigned int baud, lcr;
334 unsigned int loops = 1000;
335
336 spin_lock_irqsave(&port->lock, flags);
337
338 /* calculate and set baud rate */
339 baud = uart_get_baud_rate(port, termios, old, 900, 921600);
340 baud = vt8500_set_baud_rate(port, baud);
341 if (tty_termios_baud_rate(termios))
342 tty_termios_encode_baud_rate(termios, baud, baud);
343
344 /* calculate parity */
345 lcr = vt8500_read(&vt8500_port->uart, VT8500_URLCR);
346 lcr &= ~((1 << 5) | (1 << 4));
347 if (termios->c_cflag & PARENB) {
348 lcr |= (1 << 4);
349 termios->c_cflag &= ~CMSPAR;
350 if (termios->c_cflag & PARODD)
351 lcr |= (1 << 5);
352 }
353
354 /* calculate bits per char */
355 lcr &= ~(1 << 2);
356 switch (termios->c_cflag & CSIZE) {
357 case CS7:
358 break;
359 case CS8:
360 default:
361 lcr |= (1 << 2);
362 termios->c_cflag &= ~CSIZE;
363 termios->c_cflag |= CS8;
364 break;
365 }
366
367 /* calculate stop bits */
368 lcr &= ~(1 << 3);
369 if (termios->c_cflag & CSTOPB)
370 lcr |= (1 << 3);
371
372 /* set parity, bits per char, and stop bit */
373 vt8500_write(&vt8500_port->uart, lcr, VT8500_URLCR);
374
375 /* Configure status bits to ignore based on termio flags. */
376 port->read_status_mask = 0;
377 if (termios->c_iflag & IGNPAR)
378 port->read_status_mask = FER | PER;
379
380 uart_update_timeout(port, termios->c_cflag, baud);
381
382 /* Reset FIFOs */
383 vt8500_write(&vt8500_port->uart, 0x88c, VT8500_URFCR);
384 while ((vt8500_read(&vt8500_port->uart, VT8500_URFCR) & 0xc)
385 && --loops)
386 cpu_relax();
387
388 /* Every possible FIFO-related interrupt */
389 vt8500_port->ier = RX_FIFO_INTS | TX_FIFO_INTS;
390
391 /*
392 * CTS flow control
393 */
394 if (UART_ENABLE_MS(&vt8500_port->uart, termios->c_cflag))
395 vt8500_port->ier |= TCTS;
396
397 vt8500_write(&vt8500_port->uart, 0x881, VT8500_URFCR);
398 vt8500_write(&vt8500_port->uart, vt8500_port->ier, VT8500_URIER);
399
400 spin_unlock_irqrestore(&port->lock, flags);
401}
402
403static const char *vt8500_type(struct uart_port *port)
404{
405 struct vt8500_port *vt8500_port =
406 container_of(port, struct vt8500_port, uart);
407 return vt8500_port->name;
408}
409
410static void vt8500_release_port(struct uart_port *port)
411{
412}
413
414static int vt8500_request_port(struct uart_port *port)
415{
416 return 0;
417}
418
419static void vt8500_config_port(struct uart_port *port, int flags)
420{
421 port->type = PORT_VT8500;
422}
423
424static int vt8500_verify_port(struct uart_port *port,
425 struct serial_struct *ser)
426{
427 if (unlikely(ser->type != PORT_UNKNOWN && ser->type != PORT_VT8500))
428 return -EINVAL;
429 if (unlikely(port->irq != ser->irq))
430 return -EINVAL;
431 return 0;
432}
433
434static struct vt8500_port *vt8500_uart_ports[4];
435static struct uart_driver vt8500_uart_driver;
436
437#ifdef CONFIG_SERIAL_VT8500_CONSOLE
438
439static inline void wait_for_xmitr(struct uart_port *port)
440{
441 unsigned int status, tmout = 10000;
442
443 /* Wait up to 10ms for the character(s) to be sent. */
444 do {
445 status = vt8500_read(port, VT8500_URFIDX);
446
447 if (--tmout == 0)
448 break;
449 udelay(1);
450 } while (status & 0x10);
451}
452
453static void vt8500_console_putchar(struct uart_port *port, int c)
454{
455 wait_for_xmitr(port);
456 writeb(c, port->membase + VT8500_TXFIFO);
457}
458
459static void vt8500_console_write(struct console *co, const char *s,
460 unsigned int count)
461{
462 struct vt8500_port *vt8500_port = vt8500_uart_ports[co->index];
463 unsigned long ier;
464
465 BUG_ON(co->index < 0 || co->index >= vt8500_uart_driver.nr);
466
467 ier = vt8500_read(&vt8500_port->uart, VT8500_URIER);
468 vt8500_write(&vt8500_port->uart, VT8500_URIER, 0);
469
470 uart_console_write(&vt8500_port->uart, s, count,
471 vt8500_console_putchar);
472
473 /*
474 * Finally, wait for transmitter to become empty
475 * and switch back to FIFO
476 */
477 wait_for_xmitr(&vt8500_port->uart);
478 vt8500_write(&vt8500_port->uart, VT8500_URIER, ier);
479}
480
481static int __init vt8500_console_setup(struct console *co, char *options)
482{
483 struct vt8500_port *vt8500_port;
484 int baud = 9600;
485 int bits = 8;
486 int parity = 'n';
487 int flow = 'n';
488
489 if (unlikely(co->index >= vt8500_uart_driver.nr || co->index < 0))
490 return -ENXIO;
491
492 vt8500_port = vt8500_uart_ports[co->index];
493
494 if (!vt8500_port)
495 return -ENODEV;
496
497 if (options)
498 uart_parse_options(options, &baud, &parity, &bits, &flow);
499
500 return uart_set_options(&vt8500_port->uart,
501 co, baud, parity, bits, flow);
502}
503
504static struct console vt8500_console = {
505 .name = "ttyWMT",
506 .write = vt8500_console_write,
507 .device = uart_console_device,
508 .setup = vt8500_console_setup,
509 .flags = CON_PRINTBUFFER,
510 .index = -1,
511 .data = &vt8500_uart_driver,
512};
513
514#define VT8500_CONSOLE (&vt8500_console)
515
516#else
517#define VT8500_CONSOLE NULL
518#endif
519
520static struct uart_ops vt8500_uart_pops = {
521 .tx_empty = vt8500_tx_empty,
522 .set_mctrl = vt8500_set_mctrl,
523 .get_mctrl = vt8500_get_mctrl,
524 .stop_tx = vt8500_stop_tx,
525 .start_tx = vt8500_start_tx,
526 .stop_rx = vt8500_stop_rx,
527 .enable_ms = vt8500_enable_ms,
528 .break_ctl = vt8500_break_ctl,
529 .startup = vt8500_startup,
530 .shutdown = vt8500_shutdown,
531 .set_termios = vt8500_set_termios,
532 .type = vt8500_type,
533 .release_port = vt8500_release_port,
534 .request_port = vt8500_request_port,
535 .config_port = vt8500_config_port,
536 .verify_port = vt8500_verify_port,
537};
538
539static struct uart_driver vt8500_uart_driver = {
540 .owner = THIS_MODULE,
541 .driver_name = "vt8500_serial",
542 .dev_name = "ttyWMT",
543 .nr = 6,
544 .cons = VT8500_CONSOLE,
545};
546
547static int __init vt8500_serial_probe(struct platform_device *pdev)
548{
549 struct vt8500_port *vt8500_port;
550 struct resource *mmres, *irqres;
551 int ret;
552
553 mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
554 irqres = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
555 if (!mmres || !irqres)
556 return -ENODEV;
557
558 vt8500_port = kzalloc(sizeof(struct vt8500_port), GFP_KERNEL);
559 if (!vt8500_port)
560 return -ENOMEM;
561
562 vt8500_port->uart.type = PORT_VT8500;
563 vt8500_port->uart.iotype = UPIO_MEM;
564 vt8500_port->uart.mapbase = mmres->start;
565 vt8500_port->uart.irq = irqres->start;
566 vt8500_port->uart.fifosize = 16;
567 vt8500_port->uart.ops = &vt8500_uart_pops;
568 vt8500_port->uart.line = pdev->id;
569 vt8500_port->uart.dev = &pdev->dev;
570 vt8500_port->uart.flags = UPF_IOREMAP | UPF_BOOT_AUTOCONF;
571 vt8500_port->uart.uartclk = 24000000;
572
573 snprintf(vt8500_port->name, sizeof(vt8500_port->name),
574 "VT8500 UART%d", pdev->id);
575
576 vt8500_port->uart.membase = ioremap(mmres->start, resource_size(mmres));
577 if (!vt8500_port->uart.membase) {
578 ret = -ENOMEM;
579 goto err;
580 }
581
582 vt8500_uart_ports[pdev->id] = vt8500_port;
583
584 uart_add_one_port(&vt8500_uart_driver, &vt8500_port->uart);
585
586 platform_set_drvdata(pdev, vt8500_port);
587
588 return 0;
589
590err:
591 kfree(vt8500_port);
592 return ret;
593}
594
595static int __devexit vt8500_serial_remove(struct platform_device *pdev)
596{
597 struct vt8500_port *vt8500_port = platform_get_drvdata(pdev);
598
599 platform_set_drvdata(pdev, NULL);
600 uart_remove_one_port(&vt8500_uart_driver, &vt8500_port->uart);
601 kfree(vt8500_port);
602
603 return 0;
604}
605
606static struct platform_driver vt8500_platform_driver = {
607 .probe = vt8500_serial_probe,
608 .remove = vt8500_serial_remove,
609 .driver = {
610 .name = "vt8500_serial",
611 .owner = THIS_MODULE,
612 },
613};
614
615static int __init vt8500_serial_init(void)
616{
617 int ret;
618
619 ret = uart_register_driver(&vt8500_uart_driver);
620 if (unlikely(ret))
621 return ret;
622
623 ret = platform_driver_register(&vt8500_platform_driver);
624
625 if (unlikely(ret))
626 uart_unregister_driver(&vt8500_uart_driver);
627
628 return ret;
629}
630
631static void __exit vt8500_serial_exit(void)
632{
633#ifdef CONFIG_SERIAL_VT8500_CONSOLE
634 unregister_console(&vt8500_console);
635#endif
636 platform_driver_unregister(&vt8500_platform_driver);
637 uart_unregister_driver(&vt8500_uart_driver);
638}
639
640module_init(vt8500_serial_init);
641module_exit(vt8500_serial_exit);
642
643MODULE_AUTHOR("Alexey Charkov <alchark@gmail.com>");
644MODULE_DESCRIPTION("Driver for vt8500 serial device");
645MODULE_LICENSE("GPL");
1/*
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>
36#include <linux/platform_device.h>
37
38/*
39 * UART Register offsets
40 */
41
42#define VT8500_URTDR 0x0000 /* Transmit data */
43#define VT8500_URRDR 0x0004 /* Receive data */
44#define VT8500_URDIV 0x0008 /* Clock/Baud rate divisor */
45#define VT8500_URLCR 0x000C /* Line control */
46#define VT8500_URICR 0x0010 /* IrDA control */
47#define VT8500_URIER 0x0014 /* Interrupt enable */
48#define VT8500_URISR 0x0018 /* Interrupt status */
49#define VT8500_URUSR 0x001c /* UART status */
50#define VT8500_URFCR 0x0020 /* FIFO control */
51#define VT8500_URFIDX 0x0024 /* FIFO index */
52#define VT8500_URBKR 0x0028 /* Break signal count */
53#define VT8500_URTOD 0x002c /* Time out divisor */
54#define VT8500_TXFIFO 0x1000 /* Transmit FIFO (16x8) */
55#define VT8500_RXFIFO 0x1020 /* Receive FIFO (16x10) */
56
57/*
58 * Interrupt enable and status bits
59 */
60
61#define TXDE (1 << 0) /* Tx Data empty */
62#define RXDF (1 << 1) /* Rx Data full */
63#define TXFAE (1 << 2) /* Tx FIFO almost empty */
64#define TXFE (1 << 3) /* Tx FIFO empty */
65#define RXFAF (1 << 4) /* Rx FIFO almost full */
66#define RXFF (1 << 5) /* Rx FIFO full */
67#define TXUDR (1 << 6) /* Tx underrun */
68#define RXOVER (1 << 7) /* Rx overrun */
69#define PER (1 << 8) /* Parity error */
70#define FER (1 << 9) /* Frame error */
71#define TCTS (1 << 10) /* Toggle of CTS */
72#define RXTOUT (1 << 11) /* Rx timeout */
73#define BKDONE (1 << 12) /* Break signal done */
74#define ERR (1 << 13) /* AHB error response */
75
76#define RX_FIFO_INTS (RXFAF | RXFF | RXOVER | PER | FER | RXTOUT)
77#define TX_FIFO_INTS (TXFAE | TXFE | TXUDR)
78
79struct vt8500_port {
80 struct uart_port uart;
81 char name[16];
82 struct clk *clk;
83 unsigned int ier;
84};
85
86static inline void vt8500_write(struct uart_port *port, unsigned int val,
87 unsigned int off)
88{
89 writel(val, port->membase + off);
90}
91
92static inline unsigned int vt8500_read(struct uart_port *port, unsigned int off)
93{
94 return readl(port->membase + off);
95}
96
97static void vt8500_stop_tx(struct uart_port *port)
98{
99 struct vt8500_port *vt8500_port = container_of(port,
100 struct vt8500_port,
101 uart);
102
103 vt8500_port->ier &= ~TX_FIFO_INTS;
104 vt8500_write(port, vt8500_port->ier, VT8500_URIER);
105}
106
107static void vt8500_stop_rx(struct uart_port *port)
108{
109 struct vt8500_port *vt8500_port = container_of(port,
110 struct vt8500_port,
111 uart);
112
113 vt8500_port->ier &= ~RX_FIFO_INTS;
114 vt8500_write(port, vt8500_port->ier, VT8500_URIER);
115}
116
117static void vt8500_enable_ms(struct uart_port *port)
118{
119 struct vt8500_port *vt8500_port = container_of(port,
120 struct vt8500_port,
121 uart);
122
123 vt8500_port->ier |= TCTS;
124 vt8500_write(port, vt8500_port->ier, VT8500_URIER);
125}
126
127static void handle_rx(struct uart_port *port)
128{
129 struct tty_struct *tty = tty_port_tty_get(&port->state->port);
130 if (!tty) {
131 /* Discard data: no tty available */
132 int count = (vt8500_read(port, VT8500_URFIDX) & 0x1f00) >> 8;
133 u16 ch;
134 while (count--)
135 ch = readw(port->membase + VT8500_RXFIFO);
136 return;
137 }
138
139 /*
140 * Handle overrun
141 */
142 if ((vt8500_read(port, VT8500_URISR) & RXOVER)) {
143 port->icount.overrun++;
144 tty_insert_flip_char(tty, 0, TTY_OVERRUN);
145 }
146
147 /* and now the main RX loop */
148 while (vt8500_read(port, VT8500_URFIDX) & 0x1f00) {
149 unsigned int c;
150 char flag = TTY_NORMAL;
151
152 c = readw(port->membase + VT8500_RXFIFO) & 0x3ff;
153
154 /* Mask conditions we're ignorning. */
155 c &= ~port->read_status_mask;
156
157 if (c & FER) {
158 port->icount.frame++;
159 flag = TTY_FRAME;
160 } else if (c & PER) {
161 port->icount.parity++;
162 flag = TTY_PARITY;
163 }
164 port->icount.rx++;
165
166 if (!uart_handle_sysrq_char(port, c))
167 tty_insert_flip_char(tty, c, flag);
168 }
169
170 tty_flip_buffer_push(tty);
171 tty_kref_put(tty);
172}
173
174static void handle_tx(struct uart_port *port)
175{
176 struct circ_buf *xmit = &port->state->xmit;
177
178 if (port->x_char) {
179 writeb(port->x_char, port->membase + VT8500_TXFIFO);
180 port->icount.tx++;
181 port->x_char = 0;
182 }
183 if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
184 vt8500_stop_tx(port);
185 return;
186 }
187
188 while ((vt8500_read(port, VT8500_URFIDX) & 0x1f) < 16) {
189 if (uart_circ_empty(xmit))
190 break;
191
192 writeb(xmit->buf[xmit->tail], port->membase + VT8500_TXFIFO);
193
194 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
195 port->icount.tx++;
196 }
197
198 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
199 uart_write_wakeup(port);
200
201 if (uart_circ_empty(xmit))
202 vt8500_stop_tx(port);
203}
204
205static void vt8500_start_tx(struct uart_port *port)
206{
207 struct vt8500_port *vt8500_port = container_of(port,
208 struct vt8500_port,
209 uart);
210
211 vt8500_port->ier &= ~TX_FIFO_INTS;
212 vt8500_write(port, vt8500_port->ier, VT8500_URIER);
213 handle_tx(port);
214 vt8500_port->ier |= TX_FIFO_INTS;
215 vt8500_write(port, vt8500_port->ier, VT8500_URIER);
216}
217
218static void handle_delta_cts(struct uart_port *port)
219{
220 port->icount.cts++;
221 wake_up_interruptible(&port->state->port.delta_msr_wait);
222}
223
224static irqreturn_t vt8500_irq(int irq, void *dev_id)
225{
226 struct uart_port *port = dev_id;
227 unsigned long isr;
228
229 spin_lock(&port->lock);
230 isr = vt8500_read(port, VT8500_URISR);
231
232 /* Acknowledge active status bits */
233 vt8500_write(port, isr, VT8500_URISR);
234
235 if (isr & RX_FIFO_INTS)
236 handle_rx(port);
237 if (isr & TX_FIFO_INTS)
238 handle_tx(port);
239 if (isr & TCTS)
240 handle_delta_cts(port);
241
242 spin_unlock(&port->lock);
243
244 return IRQ_HANDLED;
245}
246
247static unsigned int vt8500_tx_empty(struct uart_port *port)
248{
249 return (vt8500_read(port, VT8500_URFIDX) & 0x1f) < 16 ?
250 TIOCSER_TEMT : 0;
251}
252
253static unsigned int vt8500_get_mctrl(struct uart_port *port)
254{
255 unsigned int usr;
256
257 usr = vt8500_read(port, VT8500_URUSR);
258 if (usr & (1 << 4))
259 return TIOCM_CTS;
260 else
261 return 0;
262}
263
264static void vt8500_set_mctrl(struct uart_port *port, unsigned int mctrl)
265{
266}
267
268static void vt8500_break_ctl(struct uart_port *port, int break_ctl)
269{
270 if (break_ctl)
271 vt8500_write(port, vt8500_read(port, VT8500_URLCR) | (1 << 9),
272 VT8500_URLCR);
273}
274
275static int vt8500_set_baud_rate(struct uart_port *port, unsigned int baud)
276{
277 unsigned long div;
278 unsigned int loops = 1000;
279
280 div = vt8500_read(port, VT8500_URDIV) & ~(0x3ff);
281
282 if (unlikely((baud < 900) || (baud > 921600)))
283 div |= 7;
284 else
285 div |= (921600 / baud) - 1;
286
287 while ((vt8500_read(port, VT8500_URUSR) & (1 << 5)) && --loops)
288 cpu_relax();
289 vt8500_write(port, div, VT8500_URDIV);
290
291 return baud;
292}
293
294static int vt8500_startup(struct uart_port *port)
295{
296 struct vt8500_port *vt8500_port =
297 container_of(port, struct vt8500_port, uart);
298 int ret;
299
300 snprintf(vt8500_port->name, sizeof(vt8500_port->name),
301 "vt8500_serial%d", port->line);
302
303 ret = request_irq(port->irq, vt8500_irq, IRQF_TRIGGER_HIGH,
304 vt8500_port->name, port);
305 if (unlikely(ret))
306 return ret;
307
308 vt8500_write(port, 0x03, VT8500_URLCR); /* enable TX & RX */
309
310 return 0;
311}
312
313static void vt8500_shutdown(struct uart_port *port)
314{
315 struct vt8500_port *vt8500_port =
316 container_of(port, struct vt8500_port, uart);
317
318 vt8500_port->ier = 0;
319
320 /* disable interrupts and FIFOs */
321 vt8500_write(&vt8500_port->uart, 0, VT8500_URIER);
322 vt8500_write(&vt8500_port->uart, 0x880, VT8500_URFCR);
323 free_irq(port->irq, port);
324}
325
326static void vt8500_set_termios(struct uart_port *port,
327 struct ktermios *termios,
328 struct ktermios *old)
329{
330 struct vt8500_port *vt8500_port =
331 container_of(port, struct vt8500_port, uart);
332 unsigned long flags;
333 unsigned int baud, lcr;
334 unsigned int loops = 1000;
335
336 spin_lock_irqsave(&port->lock, flags);
337
338 /* calculate and set baud rate */
339 baud = uart_get_baud_rate(port, termios, old, 900, 921600);
340 baud = vt8500_set_baud_rate(port, baud);
341 if (tty_termios_baud_rate(termios))
342 tty_termios_encode_baud_rate(termios, baud, baud);
343
344 /* calculate parity */
345 lcr = vt8500_read(&vt8500_port->uart, VT8500_URLCR);
346 lcr &= ~((1 << 5) | (1 << 4));
347 if (termios->c_cflag & PARENB) {
348 lcr |= (1 << 4);
349 termios->c_cflag &= ~CMSPAR;
350 if (termios->c_cflag & PARODD)
351 lcr |= (1 << 5);
352 }
353
354 /* calculate bits per char */
355 lcr &= ~(1 << 2);
356 switch (termios->c_cflag & CSIZE) {
357 case CS7:
358 break;
359 case CS8:
360 default:
361 lcr |= (1 << 2);
362 termios->c_cflag &= ~CSIZE;
363 termios->c_cflag |= CS8;
364 break;
365 }
366
367 /* calculate stop bits */
368 lcr &= ~(1 << 3);
369 if (termios->c_cflag & CSTOPB)
370 lcr |= (1 << 3);
371
372 /* set parity, bits per char, and stop bit */
373 vt8500_write(&vt8500_port->uart, lcr, VT8500_URLCR);
374
375 /* Configure status bits to ignore based on termio flags. */
376 port->read_status_mask = 0;
377 if (termios->c_iflag & IGNPAR)
378 port->read_status_mask = FER | PER;
379
380 uart_update_timeout(port, termios->c_cflag, baud);
381
382 /* Reset FIFOs */
383 vt8500_write(&vt8500_port->uart, 0x88c, VT8500_URFCR);
384 while ((vt8500_read(&vt8500_port->uart, VT8500_URFCR) & 0xc)
385 && --loops)
386 cpu_relax();
387
388 /* Every possible FIFO-related interrupt */
389 vt8500_port->ier = RX_FIFO_INTS | TX_FIFO_INTS;
390
391 /*
392 * CTS flow control
393 */
394 if (UART_ENABLE_MS(&vt8500_port->uart, termios->c_cflag))
395 vt8500_port->ier |= TCTS;
396
397 vt8500_write(&vt8500_port->uart, 0x881, VT8500_URFCR);
398 vt8500_write(&vt8500_port->uart, vt8500_port->ier, VT8500_URIER);
399
400 spin_unlock_irqrestore(&port->lock, flags);
401}
402
403static const char *vt8500_type(struct uart_port *port)
404{
405 struct vt8500_port *vt8500_port =
406 container_of(port, struct vt8500_port, uart);
407 return vt8500_port->name;
408}
409
410static void vt8500_release_port(struct uart_port *port)
411{
412}
413
414static int vt8500_request_port(struct uart_port *port)
415{
416 return 0;
417}
418
419static void vt8500_config_port(struct uart_port *port, int flags)
420{
421 port->type = PORT_VT8500;
422}
423
424static int vt8500_verify_port(struct uart_port *port,
425 struct serial_struct *ser)
426{
427 if (unlikely(ser->type != PORT_UNKNOWN && ser->type != PORT_VT8500))
428 return -EINVAL;
429 if (unlikely(port->irq != ser->irq))
430 return -EINVAL;
431 return 0;
432}
433
434static struct vt8500_port *vt8500_uart_ports[4];
435static struct uart_driver vt8500_uart_driver;
436
437#ifdef CONFIG_SERIAL_VT8500_CONSOLE
438
439static inline void wait_for_xmitr(struct uart_port *port)
440{
441 unsigned int status, tmout = 10000;
442
443 /* Wait up to 10ms for the character(s) to be sent. */
444 do {
445 status = vt8500_read(port, VT8500_URFIDX);
446
447 if (--tmout == 0)
448 break;
449 udelay(1);
450 } while (status & 0x10);
451}
452
453static void vt8500_console_putchar(struct uart_port *port, int c)
454{
455 wait_for_xmitr(port);
456 writeb(c, port->membase + VT8500_TXFIFO);
457}
458
459static void vt8500_console_write(struct console *co, const char *s,
460 unsigned int count)
461{
462 struct vt8500_port *vt8500_port = vt8500_uart_ports[co->index];
463 unsigned long ier;
464
465 BUG_ON(co->index < 0 || co->index >= vt8500_uart_driver.nr);
466
467 ier = vt8500_read(&vt8500_port->uart, VT8500_URIER);
468 vt8500_write(&vt8500_port->uart, VT8500_URIER, 0);
469
470 uart_console_write(&vt8500_port->uart, s, count,
471 vt8500_console_putchar);
472
473 /*
474 * Finally, wait for transmitter to become empty
475 * and switch back to FIFO
476 */
477 wait_for_xmitr(&vt8500_port->uart);
478 vt8500_write(&vt8500_port->uart, VT8500_URIER, ier);
479}
480
481static int __init vt8500_console_setup(struct console *co, char *options)
482{
483 struct vt8500_port *vt8500_port;
484 int baud = 9600;
485 int bits = 8;
486 int parity = 'n';
487 int flow = 'n';
488
489 if (unlikely(co->index >= vt8500_uart_driver.nr || co->index < 0))
490 return -ENXIO;
491
492 vt8500_port = vt8500_uart_ports[co->index];
493
494 if (!vt8500_port)
495 return -ENODEV;
496
497 if (options)
498 uart_parse_options(options, &baud, &parity, &bits, &flow);
499
500 return uart_set_options(&vt8500_port->uart,
501 co, baud, parity, bits, flow);
502}
503
504static struct console vt8500_console = {
505 .name = "ttyWMT",
506 .write = vt8500_console_write,
507 .device = uart_console_device,
508 .setup = vt8500_console_setup,
509 .flags = CON_PRINTBUFFER,
510 .index = -1,
511 .data = &vt8500_uart_driver,
512};
513
514#define VT8500_CONSOLE (&vt8500_console)
515
516#else
517#define VT8500_CONSOLE NULL
518#endif
519
520static struct uart_ops vt8500_uart_pops = {
521 .tx_empty = vt8500_tx_empty,
522 .set_mctrl = vt8500_set_mctrl,
523 .get_mctrl = vt8500_get_mctrl,
524 .stop_tx = vt8500_stop_tx,
525 .start_tx = vt8500_start_tx,
526 .stop_rx = vt8500_stop_rx,
527 .enable_ms = vt8500_enable_ms,
528 .break_ctl = vt8500_break_ctl,
529 .startup = vt8500_startup,
530 .shutdown = vt8500_shutdown,
531 .set_termios = vt8500_set_termios,
532 .type = vt8500_type,
533 .release_port = vt8500_release_port,
534 .request_port = vt8500_request_port,
535 .config_port = vt8500_config_port,
536 .verify_port = vt8500_verify_port,
537};
538
539static struct uart_driver vt8500_uart_driver = {
540 .owner = THIS_MODULE,
541 .driver_name = "vt8500_serial",
542 .dev_name = "ttyWMT",
543 .nr = 6,
544 .cons = VT8500_CONSOLE,
545};
546
547static int __devinit vt8500_serial_probe(struct platform_device *pdev)
548{
549 struct vt8500_port *vt8500_port;
550 struct resource *mmres, *irqres;
551 int ret;
552
553 mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
554 irqres = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
555 if (!mmres || !irqres)
556 return -ENODEV;
557
558 vt8500_port = kzalloc(sizeof(struct vt8500_port), GFP_KERNEL);
559 if (!vt8500_port)
560 return -ENOMEM;
561
562 vt8500_port->uart.type = PORT_VT8500;
563 vt8500_port->uart.iotype = UPIO_MEM;
564 vt8500_port->uart.mapbase = mmres->start;
565 vt8500_port->uart.irq = irqres->start;
566 vt8500_port->uart.fifosize = 16;
567 vt8500_port->uart.ops = &vt8500_uart_pops;
568 vt8500_port->uart.line = pdev->id;
569 vt8500_port->uart.dev = &pdev->dev;
570 vt8500_port->uart.flags = UPF_IOREMAP | UPF_BOOT_AUTOCONF;
571 vt8500_port->uart.uartclk = 24000000;
572
573 snprintf(vt8500_port->name, sizeof(vt8500_port->name),
574 "VT8500 UART%d", pdev->id);
575
576 vt8500_port->uart.membase = ioremap(mmres->start, resource_size(mmres));
577 if (!vt8500_port->uart.membase) {
578 ret = -ENOMEM;
579 goto err;
580 }
581
582 vt8500_uart_ports[pdev->id] = vt8500_port;
583
584 uart_add_one_port(&vt8500_uart_driver, &vt8500_port->uart);
585
586 platform_set_drvdata(pdev, vt8500_port);
587
588 return 0;
589
590err:
591 kfree(vt8500_port);
592 return ret;
593}
594
595static int __devexit vt8500_serial_remove(struct platform_device *pdev)
596{
597 struct vt8500_port *vt8500_port = platform_get_drvdata(pdev);
598
599 platform_set_drvdata(pdev, NULL);
600 uart_remove_one_port(&vt8500_uart_driver, &vt8500_port->uart);
601 kfree(vt8500_port);
602
603 return 0;
604}
605
606static struct platform_driver vt8500_platform_driver = {
607 .probe = vt8500_serial_probe,
608 .remove = __devexit_p(vt8500_serial_remove),
609 .driver = {
610 .name = "vt8500_serial",
611 .owner = THIS_MODULE,
612 },
613};
614
615static int __init vt8500_serial_init(void)
616{
617 int ret;
618
619 ret = uart_register_driver(&vt8500_uart_driver);
620 if (unlikely(ret))
621 return ret;
622
623 ret = platform_driver_register(&vt8500_platform_driver);
624
625 if (unlikely(ret))
626 uart_unregister_driver(&vt8500_uart_driver);
627
628 return ret;
629}
630
631static void __exit vt8500_serial_exit(void)
632{
633#ifdef CONFIG_SERIAL_VT8500_CONSOLE
634 unregister_console(&vt8500_console);
635#endif
636 platform_driver_unregister(&vt8500_platform_driver);
637 uart_unregister_driver(&vt8500_uart_driver);
638}
639
640module_init(vt8500_serial_init);
641module_exit(vt8500_serial_exit);
642
643MODULE_AUTHOR("Alexey Charkov <alchark@gmail.com>");
644MODULE_DESCRIPTION("Driver for vt8500 serial device");
645MODULE_LICENSE("GPL");