Committer: Michael Beasley <mike@snafu.setup>
[mikesnafu-overlay.git] / drivers / serial / sc26xx.c
blobae2a9e2df777fee57f4b320cbf5523558587f03f
1 /*
2 * SC268xx.c: Serial driver for Philiphs SC2681/SC2692 devices.
4 * Copyright (C) 2006,2007 Thomas Bogendörfer (tsbogend@alpha.franken.de)
5 */
7 #include <linux/module.h>
8 #include <linux/kernel.h>
9 #include <linux/errno.h>
10 #include <linux/tty.h>
11 #include <linux/tty_flip.h>
12 #include <linux/major.h>
13 #include <linux/circ_buf.h>
14 #include <linux/serial.h>
15 #include <linux/sysrq.h>
16 #include <linux/console.h>
17 #include <linux/spinlock.h>
18 #include <linux/slab.h>
19 #include <linux/delay.h>
20 #include <linux/init.h>
21 #include <linux/platform_device.h>
22 #include <linux/irq.h>
24 #if defined(CONFIG_MAGIC_SYSRQ)
25 #define SUPPORT_SYSRQ
26 #endif
28 #include <linux/serial_core.h>
30 #define SC26XX_MAJOR 204
31 #define SC26XX_MINOR_START 205
32 #define SC26XX_NR 2
34 struct uart_sc26xx_port {
35 struct uart_port port[2];
36 u8 dsr_mask[2];
37 u8 cts_mask[2];
38 u8 dcd_mask[2];
39 u8 ri_mask[2];
40 u8 dtr_mask[2];
41 u8 rts_mask[2];
42 u8 imr;
45 /* register common to both ports */
46 #define RD_ISR 0x14
47 #define RD_IPR 0x34
49 #define WR_ACR 0x10
50 #define WR_IMR 0x14
51 #define WR_OPCR 0x34
52 #define WR_OPR_SET 0x38
53 #define WR_OPR_CLR 0x3C
55 /* access common register */
56 #define READ_SC(p, r) readb((p)->membase + RD_##r)
57 #define WRITE_SC(p, r, v) writeb((v), (p)->membase + WR_##r)
59 /* register per port */
60 #define RD_PORT_MRx 0x00
61 #define RD_PORT_SR 0x04
62 #define RD_PORT_RHR 0x0c
64 #define WR_PORT_MRx 0x00
65 #define WR_PORT_CSR 0x04
66 #define WR_PORT_CR 0x08
67 #define WR_PORT_THR 0x0c
69 /* SR bits */
70 #define SR_BREAK (1 << 7)
71 #define SR_FRAME (1 << 6)
72 #define SR_PARITY (1 << 5)
73 #define SR_OVERRUN (1 << 4)
74 #define SR_TXRDY (1 << 2)
75 #define SR_RXRDY (1 << 0)
77 #define CR_RES_MR (1 << 4)
78 #define CR_RES_RX (2 << 4)
79 #define CR_RES_TX (3 << 4)
80 #define CR_STRT_BRK (6 << 4)
81 #define CR_STOP_BRK (7 << 4)
82 #define CR_DIS_TX (1 << 3)
83 #define CR_ENA_TX (1 << 2)
84 #define CR_DIS_RX (1 << 1)
85 #define CR_ENA_RX (1 << 0)
87 /* ISR bits */
88 #define ISR_RXRDYB (1 << 5)
89 #define ISR_TXRDYB (1 << 4)
90 #define ISR_RXRDYA (1 << 1)
91 #define ISR_TXRDYA (1 << 0)
93 /* IMR bits */
94 #define IMR_RXRDY (1 << 1)
95 #define IMR_TXRDY (1 << 0)
97 /* access port register */
98 static inline u8 read_sc_port(struct uart_port *p, u8 reg)
100 return readb(p->membase + p->line * 0x20 + reg);
103 static inline void write_sc_port(struct uart_port *p, u8 reg, u8 val)
105 writeb(val, p->membase + p->line * 0x20 + reg);
108 #define READ_SC_PORT(p, r) read_sc_port(p, RD_PORT_##r)
109 #define WRITE_SC_PORT(p, r, v) write_sc_port(p, WR_PORT_##r, v)
111 static void sc26xx_enable_irq(struct uart_port *port, int mask)
113 struct uart_sc26xx_port *up;
114 int line = port->line;
116 port -= line;
117 up = container_of(port, struct uart_sc26xx_port, port[0]);
119 up->imr |= mask << (line * 4);
120 WRITE_SC(port, IMR, up->imr);
123 static void sc26xx_disable_irq(struct uart_port *port, int mask)
125 struct uart_sc26xx_port *up;
126 int line = port->line;
128 port -= line;
129 up = container_of(port, struct uart_sc26xx_port, port[0]);
131 up->imr &= ~(mask << (line * 4));
132 WRITE_SC(port, IMR, up->imr);
135 static struct tty_struct *receive_chars(struct uart_port *port)
137 struct tty_struct *tty = NULL;
138 int limit = 10000;
139 unsigned char ch;
140 char flag;
141 u8 status;
143 if (port->info != NULL) /* Unopened serial console */
144 tty = port->info->tty;
146 while (limit-- > 0) {
147 status = READ_SC_PORT(port, SR);
148 if (!(status & SR_RXRDY))
149 break;
150 ch = READ_SC_PORT(port, RHR);
152 flag = TTY_NORMAL;
153 port->icount.rx++;
155 if (unlikely(status & (SR_BREAK | SR_FRAME |
156 SR_PARITY | SR_OVERRUN))) {
157 if (status & SR_BREAK) {
158 status &= ~(SR_PARITY | SR_FRAME);
159 port->icount.brk++;
160 if (uart_handle_break(port))
161 continue;
162 } else if (status & SR_PARITY)
163 port->icount.parity++;
164 else if (status & SR_FRAME)
165 port->icount.frame++;
166 if (status & SR_OVERRUN)
167 port->icount.overrun++;
169 status &= port->read_status_mask;
170 if (status & SR_BREAK)
171 flag = TTY_BREAK;
172 else if (status & SR_PARITY)
173 flag = TTY_PARITY;
174 else if (status & SR_FRAME)
175 flag = TTY_FRAME;
178 if (uart_handle_sysrq_char(port, ch))
179 continue;
181 if (status & port->ignore_status_mask)
182 continue;
184 tty_insert_flip_char(tty, ch, flag);
186 return tty;
189 static void transmit_chars(struct uart_port *port)
191 struct circ_buf *xmit;
193 if (!port->info)
194 return;
196 xmit = &port->info->xmit;
197 if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
198 sc26xx_disable_irq(port, IMR_TXRDY);
199 return;
201 while (!uart_circ_empty(xmit)) {
202 if (!(READ_SC_PORT(port, SR) & SR_TXRDY))
203 break;
205 WRITE_SC_PORT(port, THR, xmit->buf[xmit->tail]);
206 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
207 port->icount.tx++;
209 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
210 uart_write_wakeup(port);
213 static irqreturn_t sc26xx_interrupt(int irq, void *dev_id)
215 struct uart_sc26xx_port *up = dev_id;
216 struct tty_struct *tty;
217 unsigned long flags;
218 u8 isr;
220 spin_lock_irqsave(&up->port[0].lock, flags);
222 tty = NULL;
223 isr = READ_SC(&up->port[0], ISR);
224 if (isr & ISR_TXRDYA)
225 transmit_chars(&up->port[0]);
226 if (isr & ISR_RXRDYA)
227 tty = receive_chars(&up->port[0]);
229 spin_unlock(&up->port[0].lock);
231 if (tty)
232 tty_flip_buffer_push(tty);
234 spin_lock(&up->port[1].lock);
236 tty = NULL;
237 if (isr & ISR_TXRDYB)
238 transmit_chars(&up->port[1]);
239 if (isr & ISR_RXRDYB)
240 tty = receive_chars(&up->port[1]);
242 spin_unlock_irqrestore(&up->port[1].lock, flags);
244 if (tty)
245 tty_flip_buffer_push(tty);
247 return IRQ_HANDLED;
250 /* port->lock is not held. */
251 static unsigned int sc26xx_tx_empty(struct uart_port *port)
253 return (READ_SC_PORT(port, SR) & SR_TXRDY) ? TIOCSER_TEMT : 0;
256 /* port->lock held by caller. */
257 static void sc26xx_set_mctrl(struct uart_port *port, unsigned int mctrl)
259 struct uart_sc26xx_port *up;
260 int line = port->line;
262 port -= line;
263 up = container_of(port, struct uart_sc26xx_port, port[0]);
265 if (up->dtr_mask[line]) {
266 if (mctrl & TIOCM_DTR)
267 WRITE_SC(port, OPR_SET, up->dtr_mask[line]);
268 else
269 WRITE_SC(port, OPR_CLR, up->dtr_mask[line]);
271 if (up->rts_mask[line]) {
272 if (mctrl & TIOCM_RTS)
273 WRITE_SC(port, OPR_SET, up->rts_mask[line]);
274 else
275 WRITE_SC(port, OPR_CLR, up->rts_mask[line]);
279 /* port->lock is held by caller and interrupts are disabled. */
280 static unsigned int sc26xx_get_mctrl(struct uart_port *port)
282 struct uart_sc26xx_port *up;
283 int line = port->line;
284 unsigned int mctrl = TIOCM_DSR | TIOCM_CTS | TIOCM_CAR;
285 u8 ipr;
287 port -= line;
288 up = container_of(port, struct uart_sc26xx_port, port[0]);
289 ipr = READ_SC(port, IPR) ^ 0xff;
291 if (up->dsr_mask[line]) {
292 mctrl &= ~TIOCM_DSR;
293 mctrl |= ipr & up->dsr_mask[line] ? TIOCM_DSR : 0;
295 if (up->cts_mask[line]) {
296 mctrl &= ~TIOCM_CTS;
297 mctrl |= ipr & up->cts_mask[line] ? TIOCM_CTS : 0;
299 if (up->dcd_mask[line]) {
300 mctrl &= ~TIOCM_CAR;
301 mctrl |= ipr & up->dcd_mask[line] ? TIOCM_CAR : 0;
303 if (up->ri_mask[line]) {
304 mctrl &= ~TIOCM_RNG;
305 mctrl |= ipr & up->ri_mask[line] ? TIOCM_RNG : 0;
307 return mctrl;
310 /* port->lock held by caller. */
311 static void sc26xx_stop_tx(struct uart_port *port)
313 return;
316 /* port->lock held by caller. */
317 static void sc26xx_start_tx(struct uart_port *port)
319 struct circ_buf *xmit = &port->info->xmit;
321 while (!uart_circ_empty(xmit)) {
322 if (!(READ_SC_PORT(port, SR) & SR_TXRDY)) {
323 sc26xx_enable_irq(port, IMR_TXRDY);
324 break;
326 WRITE_SC_PORT(port, THR, xmit->buf[xmit->tail]);
327 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
328 port->icount.tx++;
332 /* port->lock held by caller. */
333 static void sc26xx_stop_rx(struct uart_port *port)
337 /* port->lock held by caller. */
338 static void sc26xx_enable_ms(struct uart_port *port)
342 /* port->lock is not held. */
343 static void sc26xx_break_ctl(struct uart_port *port, int break_state)
345 if (break_state == -1)
346 WRITE_SC_PORT(port, CR, CR_STRT_BRK);
347 else
348 WRITE_SC_PORT(port, CR, CR_STOP_BRK);
351 /* port->lock is not held. */
352 static int sc26xx_startup(struct uart_port *port)
354 sc26xx_disable_irq(port, IMR_TXRDY | IMR_RXRDY);
355 WRITE_SC(port, OPCR, 0);
357 /* reset tx and rx */
358 WRITE_SC_PORT(port, CR, CR_RES_RX);
359 WRITE_SC_PORT(port, CR, CR_RES_TX);
361 /* start rx/tx */
362 WRITE_SC_PORT(port, CR, CR_ENA_TX | CR_ENA_RX);
364 /* enable irqs */
365 sc26xx_enable_irq(port, IMR_RXRDY);
366 return 0;
369 /* port->lock is not held. */
370 static void sc26xx_shutdown(struct uart_port *port)
372 /* disable interrupst */
373 sc26xx_disable_irq(port, IMR_TXRDY | IMR_RXRDY);
375 /* stop tx/rx */
376 WRITE_SC_PORT(port, CR, CR_DIS_TX | CR_DIS_RX);
379 /* port->lock is not held. */
380 static void sc26xx_set_termios(struct uart_port *port, struct ktermios *termios,
381 struct ktermios *old)
383 unsigned int baud = uart_get_baud_rate(port, termios, old, 0, 4000000);
384 unsigned int quot = uart_get_divisor(port, baud);
385 unsigned int iflag, cflag;
386 unsigned long flags;
387 u8 mr1, mr2, csr;
389 spin_lock_irqsave(&port->lock, flags);
391 while ((READ_SC_PORT(port, SR) & ((1 << 3) | (1 << 2))) != 0xc)
392 udelay(2);
394 WRITE_SC_PORT(port, CR, CR_DIS_TX | CR_DIS_RX);
396 iflag = termios->c_iflag;
397 cflag = termios->c_cflag;
399 port->read_status_mask = SR_OVERRUN;
400 if (iflag & INPCK)
401 port->read_status_mask |= SR_PARITY | SR_FRAME;
402 if (iflag & (BRKINT | PARMRK))
403 port->read_status_mask |= SR_BREAK;
405 port->ignore_status_mask = 0;
406 if (iflag & IGNBRK)
407 port->ignore_status_mask |= SR_BREAK;
408 if ((cflag & CREAD) == 0)
409 port->ignore_status_mask |= SR_BREAK | SR_FRAME |
410 SR_PARITY | SR_OVERRUN;
412 switch (cflag & CSIZE) {
413 case CS5:
414 mr1 = 0x00;
415 break;
416 case CS6:
417 mr1 = 0x01;
418 break;
419 case CS7:
420 mr1 = 0x02;
421 break;
422 default:
423 case CS8:
424 mr1 = 0x03;
425 break;
427 mr2 = 0x07;
428 if (cflag & CSTOPB)
429 mr2 = 0x0f;
430 if (cflag & PARENB) {
431 if (cflag & PARODD)
432 mr1 |= (1 << 2);
433 } else
434 mr1 |= (2 << 3);
436 switch (baud) {
437 case 50:
438 csr = 0x00;
439 break;
440 case 110:
441 csr = 0x11;
442 break;
443 case 134:
444 csr = 0x22;
445 break;
446 case 200:
447 csr = 0x33;
448 break;
449 case 300:
450 csr = 0x44;
451 break;
452 case 600:
453 csr = 0x55;
454 break;
455 case 1200:
456 csr = 0x66;
457 break;
458 case 2400:
459 csr = 0x88;
460 break;
461 case 4800:
462 csr = 0x99;
463 break;
464 default:
465 case 9600:
466 csr = 0xbb;
467 break;
468 case 19200:
469 csr = 0xcc;
470 break;
473 WRITE_SC_PORT(port, CR, CR_RES_MR);
474 WRITE_SC_PORT(port, MRx, mr1);
475 WRITE_SC_PORT(port, MRx, mr2);
477 WRITE_SC(port, ACR, 0x80);
478 WRITE_SC_PORT(port, CSR, csr);
480 /* reset tx and rx */
481 WRITE_SC_PORT(port, CR, CR_RES_RX);
482 WRITE_SC_PORT(port, CR, CR_RES_TX);
484 WRITE_SC_PORT(port, CR, CR_ENA_TX | CR_ENA_RX);
485 while ((READ_SC_PORT(port, SR) & ((1 << 3) | (1 << 2))) != 0xc)
486 udelay(2);
488 /* XXX */
489 uart_update_timeout(port, cflag,
490 (port->uartclk / (16 * quot)));
492 spin_unlock_irqrestore(&port->lock, flags);
495 static const char *sc26xx_type(struct uart_port *port)
497 return "SC26XX";
500 static void sc26xx_release_port(struct uart_port *port)
504 static int sc26xx_request_port(struct uart_port *port)
506 return 0;
509 static void sc26xx_config_port(struct uart_port *port, int flags)
513 static int sc26xx_verify_port(struct uart_port *port, struct serial_struct *ser)
515 return -EINVAL;
518 static struct uart_ops sc26xx_ops = {
519 .tx_empty = sc26xx_tx_empty,
520 .set_mctrl = sc26xx_set_mctrl,
521 .get_mctrl = sc26xx_get_mctrl,
522 .stop_tx = sc26xx_stop_tx,
523 .start_tx = sc26xx_start_tx,
524 .stop_rx = sc26xx_stop_rx,
525 .enable_ms = sc26xx_enable_ms,
526 .break_ctl = sc26xx_break_ctl,
527 .startup = sc26xx_startup,
528 .shutdown = sc26xx_shutdown,
529 .set_termios = sc26xx_set_termios,
530 .type = sc26xx_type,
531 .release_port = sc26xx_release_port,
532 .request_port = sc26xx_request_port,
533 .config_port = sc26xx_config_port,
534 .verify_port = sc26xx_verify_port,
537 static struct uart_port *sc26xx_port;
539 #ifdef CONFIG_SERIAL_SC26XX_CONSOLE
540 static void sc26xx_console_putchar(struct uart_port *port, char c)
542 unsigned long flags;
543 int limit = 1000000;
545 spin_lock_irqsave(&port->lock, flags);
547 while (limit-- > 0) {
548 if (READ_SC_PORT(port, SR) & SR_TXRDY) {
549 WRITE_SC_PORT(port, THR, c);
550 break;
552 udelay(2);
555 spin_unlock_irqrestore(&port->lock, flags);
558 static void sc26xx_console_write(struct console *con, const char *s, unsigned n)
560 struct uart_port *port = sc26xx_port;
561 int i;
563 for (i = 0; i < n; i++) {
564 if (*s == '\n')
565 sc26xx_console_putchar(port, '\r');
566 sc26xx_console_putchar(port, *s++);
570 static int __init sc26xx_console_setup(struct console *con, char *options)
572 struct uart_port *port = sc26xx_port;
573 int baud = 9600;
574 int bits = 8;
575 int parity = 'n';
576 int flow = 'n';
578 if (port->type != PORT_SC26XX)
579 return -1;
581 printk(KERN_INFO "Console: ttySC%d (SC26XX)\n", con->index);
582 if (options)
583 uart_parse_options(options, &baud, &parity, &bits, &flow);
585 return uart_set_options(port, con, baud, parity, bits, flow);
588 static struct uart_driver sc26xx_reg;
589 static struct console sc26xx_console = {
590 .name = "ttySC",
591 .write = sc26xx_console_write,
592 .device = uart_console_device,
593 .setup = sc26xx_console_setup,
594 .flags = CON_PRINTBUFFER,
595 .index = -1,
596 .data = &sc26xx_reg,
598 #define SC26XX_CONSOLE &sc26xx_console
599 #else
600 #define SC26XX_CONSOLE NULL
601 #endif
603 static struct uart_driver sc26xx_reg = {
604 .owner = THIS_MODULE,
605 .driver_name = "SC26xx",
606 .dev_name = "ttySC",
607 .major = SC26XX_MAJOR,
608 .minor = SC26XX_MINOR_START,
609 .nr = SC26XX_NR,
610 .cons = SC26XX_CONSOLE,
613 static u8 sc26xx_flags2mask(unsigned int flags, unsigned int bitpos)
615 unsigned int bit = (flags >> bitpos) & 15;
617 return bit ? (1 << (bit - 1)) : 0;
620 static void __devinit sc26xx_init_masks(struct uart_sc26xx_port *up,
621 int line, unsigned int data)
623 up->dtr_mask[line] = sc26xx_flags2mask(data, 0);
624 up->rts_mask[line] = sc26xx_flags2mask(data, 4);
625 up->dsr_mask[line] = sc26xx_flags2mask(data, 8);
626 up->cts_mask[line] = sc26xx_flags2mask(data, 12);
627 up->dcd_mask[line] = sc26xx_flags2mask(data, 16);
628 up->ri_mask[line] = sc26xx_flags2mask(data, 20);
631 static int __devinit sc26xx_probe(struct platform_device *dev)
633 struct resource *res;
634 struct uart_sc26xx_port *up;
635 unsigned int *sc26xx_data = dev->dev.platform_data;
636 int err;
638 res = platform_get_resource(dev, IORESOURCE_MEM, 0);
639 if (!res)
640 return -ENODEV;
642 up = kzalloc(sizeof *up, GFP_KERNEL);
643 if (unlikely(!up))
644 return -ENOMEM;
646 up->port[0].line = 0;
647 up->port[0].ops = &sc26xx_ops;
648 up->port[0].type = PORT_SC26XX;
649 up->port[0].uartclk = (29491200 / 16); /* arbitrary */
651 up->port[0].mapbase = res->start;
652 up->port[0].membase = ioremap_nocache(up->port[0].mapbase, 0x40);
653 up->port[0].iotype = UPIO_MEM;
654 up->port[0].irq = platform_get_irq(dev, 0);
656 up->port[0].dev = &dev->dev;
658 sc26xx_init_masks(up, 0, sc26xx_data[0]);
660 sc26xx_port = &up->port[0];
662 up->port[1].line = 1;
663 up->port[1].ops = &sc26xx_ops;
664 up->port[1].type = PORT_SC26XX;
665 up->port[1].uartclk = (29491200 / 16); /* arbitrary */
667 up->port[1].mapbase = up->port[0].mapbase;
668 up->port[1].membase = up->port[0].membase;
669 up->port[1].iotype = UPIO_MEM;
670 up->port[1].irq = up->port[0].irq;
672 up->port[1].dev = &dev->dev;
674 sc26xx_init_masks(up, 1, sc26xx_data[1]);
676 err = uart_register_driver(&sc26xx_reg);
677 if (err)
678 goto out_free_port;
680 sc26xx_reg.tty_driver->name_base = sc26xx_reg.minor;
682 err = uart_add_one_port(&sc26xx_reg, &up->port[0]);
683 if (err)
684 goto out_unregister_driver;
686 err = uart_add_one_port(&sc26xx_reg, &up->port[1]);
687 if (err)
688 goto out_remove_port0;
690 err = request_irq(up->port[0].irq, sc26xx_interrupt, 0, "sc26xx", up);
691 if (err)
692 goto out_remove_ports;
694 dev_set_drvdata(&dev->dev, up);
695 return 0;
697 out_remove_ports:
698 uart_remove_one_port(&sc26xx_reg, &up->port[1]);
699 out_remove_port0:
700 uart_remove_one_port(&sc26xx_reg, &up->port[0]);
702 out_unregister_driver:
703 uart_unregister_driver(&sc26xx_reg);
705 out_free_port:
706 kfree(up);
707 sc26xx_port = NULL;
708 return err;
712 static int __exit sc26xx_driver_remove(struct platform_device *dev)
714 struct uart_sc26xx_port *up = dev_get_drvdata(&dev->dev);
716 free_irq(up->port[0].irq, up);
718 uart_remove_one_port(&sc26xx_reg, &up->port[0]);
719 uart_remove_one_port(&sc26xx_reg, &up->port[1]);
721 uart_unregister_driver(&sc26xx_reg);
723 kfree(up);
724 sc26xx_port = NULL;
726 dev_set_drvdata(&dev->dev, NULL);
727 return 0;
730 static struct platform_driver sc26xx_driver = {
731 .probe = sc26xx_probe,
732 .remove = __devexit_p(sc26xx_driver_remove),
733 .driver = {
734 .name = "SC26xx",
735 .owner = THIS_MODULE,
739 static int __init sc26xx_init(void)
741 return platform_driver_register(&sc26xx_driver);
744 static void __exit sc26xx_exit(void)
746 platform_driver_unregister(&sc26xx_driver);
749 module_init(sc26xx_init);
750 module_exit(sc26xx_exit);
753 MODULE_AUTHOR("Thomas Bogendörfer");
754 MODULE_DESCRIPTION("SC681/SC2692 serial driver");
755 MODULE_VERSION("1.0");
756 MODULE_LICENSE("GPL");
757 MODULE_ALIAS("platform:SC26xx");