RT-AC56 3.0.0.4.374.37 core
[tomato.git] / release / src-rt-6.x.4708 / linux / linux-2.6.36 / drivers / serial / uartlite.c
blob9b03d7b3e4567fa54d8c4603cd8eaabdd715ff90
1 /*
2 * uartlite.c: Serial driver for Xilinx uartlite serial controller
4 * Copyright (C) 2006 Peter Korsgaard <jacmet@sunsite.dk>
5 * Copyright (C) 2007 Secret Lab Technologies Ltd.
7 * This file is licensed under the terms of the GNU General Public License
8 * version 2. This program is licensed "as is" without any warranty of any
9 * kind, whether express or implied.
12 #include <linux/platform_device.h>
13 #include <linux/module.h>
14 #include <linux/console.h>
15 #include <linux/serial.h>
16 #include <linux/serial_core.h>
17 #include <linux/tty.h>
18 #include <linux/delay.h>
19 #include <linux/interrupt.h>
20 #include <linux/init.h>
21 #include <asm/io.h>
22 #if defined(CONFIG_OF) && (defined(CONFIG_PPC32) || defined(CONFIG_MICROBLAZE))
23 #include <linux/of.h>
24 #include <linux/of_address.h>
25 #include <linux/of_device.h>
26 #include <linux/of_platform.h>
28 /* Match table for of_platform binding */
29 static struct of_device_id ulite_of_match[] __devinitdata = {
30 { .compatible = "xlnx,opb-uartlite-1.00.b", },
31 { .compatible = "xlnx,xps-uartlite-1.00.a", },
34 MODULE_DEVICE_TABLE(of, ulite_of_match);
36 #endif
38 #define ULITE_NAME "ttyUL"
39 #define ULITE_MAJOR 204
40 #define ULITE_MINOR 187
41 #define ULITE_NR_UARTS 4
43 /* ---------------------------------------------------------------------
44 * Register definitions
46 * For register details see datasheet:
47 * http://www.xilinx.com/bvdocs/ipcenter/data_sheet/opb_uartlite.pdf
50 #define ULITE_RX 0x00
51 #define ULITE_TX 0x04
52 #define ULITE_STATUS 0x08
53 #define ULITE_CONTROL 0x0c
55 #define ULITE_REGION 16
57 #define ULITE_STATUS_RXVALID 0x01
58 #define ULITE_STATUS_RXFULL 0x02
59 #define ULITE_STATUS_TXEMPTY 0x04
60 #define ULITE_STATUS_TXFULL 0x08
61 #define ULITE_STATUS_IE 0x10
62 #define ULITE_STATUS_OVERRUN 0x20
63 #define ULITE_STATUS_FRAME 0x40
64 #define ULITE_STATUS_PARITY 0x80
66 #define ULITE_CONTROL_RST_TX 0x01
67 #define ULITE_CONTROL_RST_RX 0x02
68 #define ULITE_CONTROL_IE 0x10
71 static struct uart_port ulite_ports[ULITE_NR_UARTS];
73 /* ---------------------------------------------------------------------
74 * Core UART driver operations
77 static int ulite_receive(struct uart_port *port, int stat)
79 struct tty_struct *tty = port->state->port.tty;
80 unsigned char ch = 0;
81 char flag = TTY_NORMAL;
83 if ((stat & (ULITE_STATUS_RXVALID | ULITE_STATUS_OVERRUN
84 | ULITE_STATUS_FRAME)) == 0)
85 return 0;
87 /* stats */
88 if (stat & ULITE_STATUS_RXVALID) {
89 port->icount.rx++;
90 ch = ioread32be(port->membase + ULITE_RX);
92 if (stat & ULITE_STATUS_PARITY)
93 port->icount.parity++;
96 if (stat & ULITE_STATUS_OVERRUN)
97 port->icount.overrun++;
99 if (stat & ULITE_STATUS_FRAME)
100 port->icount.frame++;
103 /* drop byte with parity error if IGNPAR specificed */
104 if (stat & port->ignore_status_mask & ULITE_STATUS_PARITY)
105 stat &= ~ULITE_STATUS_RXVALID;
107 stat &= port->read_status_mask;
109 if (stat & ULITE_STATUS_PARITY)
110 flag = TTY_PARITY;
113 stat &= ~port->ignore_status_mask;
115 if (stat & ULITE_STATUS_RXVALID)
116 tty_insert_flip_char(tty, ch, flag);
118 if (stat & ULITE_STATUS_FRAME)
119 tty_insert_flip_char(tty, 0, TTY_FRAME);
121 if (stat & ULITE_STATUS_OVERRUN)
122 tty_insert_flip_char(tty, 0, TTY_OVERRUN);
124 return 1;
127 static int ulite_transmit(struct uart_port *port, int stat)
129 struct circ_buf *xmit = &port->state->xmit;
131 if (stat & ULITE_STATUS_TXFULL)
132 return 0;
134 if (port->x_char) {
135 iowrite32be(port->x_char, port->membase + ULITE_TX);
136 port->x_char = 0;
137 port->icount.tx++;
138 return 1;
141 if (uart_circ_empty(xmit) || uart_tx_stopped(port))
142 return 0;
144 iowrite32be(xmit->buf[xmit->tail], port->membase + ULITE_TX);
145 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE-1);
146 port->icount.tx++;
148 /* wake up */
149 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
150 uart_write_wakeup(port);
152 return 1;
155 static irqreturn_t ulite_isr(int irq, void *dev_id)
157 struct uart_port *port = dev_id;
158 int busy, n = 0;
160 do {
161 int stat = ioread32be(port->membase + ULITE_STATUS);
162 busy = ulite_receive(port, stat);
163 busy |= ulite_transmit(port, stat);
164 n++;
165 } while (busy);
167 /* work done? */
168 if (n > 1) {
169 tty_flip_buffer_push(port->state->port.tty);
170 return IRQ_HANDLED;
171 } else {
172 return IRQ_NONE;
176 static unsigned int ulite_tx_empty(struct uart_port *port)
178 unsigned long flags;
179 unsigned int ret;
181 spin_lock_irqsave(&port->lock, flags);
182 ret = ioread32be(port->membase + ULITE_STATUS);
183 spin_unlock_irqrestore(&port->lock, flags);
185 return ret & ULITE_STATUS_TXEMPTY ? TIOCSER_TEMT : 0;
188 static unsigned int ulite_get_mctrl(struct uart_port *port)
190 return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
193 static void ulite_set_mctrl(struct uart_port *port, unsigned int mctrl)
195 /* N/A */
198 static void ulite_stop_tx(struct uart_port *port)
200 /* N/A */
203 static void ulite_start_tx(struct uart_port *port)
205 ulite_transmit(port, ioread32be(port->membase + ULITE_STATUS));
208 static void ulite_stop_rx(struct uart_port *port)
210 /* don't forward any more data (like !CREAD) */
211 port->ignore_status_mask = ULITE_STATUS_RXVALID | ULITE_STATUS_PARITY
212 | ULITE_STATUS_FRAME | ULITE_STATUS_OVERRUN;
215 static void ulite_enable_ms(struct uart_port *port)
217 /* N/A */
220 static void ulite_break_ctl(struct uart_port *port, int ctl)
222 /* N/A */
225 static int ulite_startup(struct uart_port *port)
227 int ret;
229 ret = request_irq(port->irq, ulite_isr,
230 IRQF_SHARED | IRQF_SAMPLE_RANDOM, "uartlite", port);
231 if (ret)
232 return ret;
234 iowrite32be(ULITE_CONTROL_RST_RX | ULITE_CONTROL_RST_TX,
235 port->membase + ULITE_CONTROL);
236 iowrite32be(ULITE_CONTROL_IE, port->membase + ULITE_CONTROL);
238 return 0;
241 static void ulite_shutdown(struct uart_port *port)
243 iowrite32be(0, port->membase + ULITE_CONTROL);
244 ioread32be(port->membase + ULITE_CONTROL); /* dummy */
245 free_irq(port->irq, port);
248 static void ulite_set_termios(struct uart_port *port, struct ktermios *termios,
249 struct ktermios *old)
251 unsigned long flags;
252 unsigned int baud;
254 spin_lock_irqsave(&port->lock, flags);
256 port->read_status_mask = ULITE_STATUS_RXVALID | ULITE_STATUS_OVERRUN
257 | ULITE_STATUS_TXFULL;
259 if (termios->c_iflag & INPCK)
260 port->read_status_mask |=
261 ULITE_STATUS_PARITY | ULITE_STATUS_FRAME;
263 port->ignore_status_mask = 0;
264 if (termios->c_iflag & IGNPAR)
265 port->ignore_status_mask |= ULITE_STATUS_PARITY
266 | ULITE_STATUS_FRAME | ULITE_STATUS_OVERRUN;
268 /* ignore all characters if CREAD is not set */
269 if ((termios->c_cflag & CREAD) == 0)
270 port->ignore_status_mask |=
271 ULITE_STATUS_RXVALID | ULITE_STATUS_PARITY
272 | ULITE_STATUS_FRAME | ULITE_STATUS_OVERRUN;
274 /* update timeout */
275 baud = uart_get_baud_rate(port, termios, old, 0, 460800);
276 uart_update_timeout(port, termios->c_cflag, baud);
278 spin_unlock_irqrestore(&port->lock, flags);
281 static const char *ulite_type(struct uart_port *port)
283 return port->type == PORT_UARTLITE ? "uartlite" : NULL;
286 static void ulite_release_port(struct uart_port *port)
288 release_mem_region(port->mapbase, ULITE_REGION);
289 iounmap(port->membase);
290 port->membase = NULL;
293 static int ulite_request_port(struct uart_port *port)
295 pr_debug("ulite console: port=%p; port->mapbase=%llx\n",
296 port, (unsigned long long) port->mapbase);
298 if (!request_mem_region(port->mapbase, ULITE_REGION, "uartlite")) {
299 dev_err(port->dev, "Memory region busy\n");
300 return -EBUSY;
303 port->membase = ioremap(port->mapbase, ULITE_REGION);
304 if (!port->membase) {
305 dev_err(port->dev, "Unable to map registers\n");
306 release_mem_region(port->mapbase, ULITE_REGION);
307 return -EBUSY;
310 return 0;
313 static void ulite_config_port(struct uart_port *port, int flags)
315 if (!ulite_request_port(port))
316 port->type = PORT_UARTLITE;
319 static int ulite_verify_port(struct uart_port *port, struct serial_struct *ser)
321 /* we don't want the core code to modify any port params */
322 return -EINVAL;
325 static struct uart_ops ulite_ops = {
326 .tx_empty = ulite_tx_empty,
327 .set_mctrl = ulite_set_mctrl,
328 .get_mctrl = ulite_get_mctrl,
329 .stop_tx = ulite_stop_tx,
330 .start_tx = ulite_start_tx,
331 .stop_rx = ulite_stop_rx,
332 .enable_ms = ulite_enable_ms,
333 .break_ctl = ulite_break_ctl,
334 .startup = ulite_startup,
335 .shutdown = ulite_shutdown,
336 .set_termios = ulite_set_termios,
337 .type = ulite_type,
338 .release_port = ulite_release_port,
339 .request_port = ulite_request_port,
340 .config_port = ulite_config_port,
341 .verify_port = ulite_verify_port
344 /* ---------------------------------------------------------------------
345 * Console driver operations
348 #ifdef CONFIG_SERIAL_UARTLITE_CONSOLE
349 static void ulite_console_wait_tx(struct uart_port *port)
351 int i;
352 u8 val;
354 /* Spin waiting for TX fifo to have space available */
355 for (i = 0; i < 100000; i++) {
356 val = ioread32be(port->membase + ULITE_STATUS);
357 if ((val & ULITE_STATUS_TXFULL) == 0)
358 break;
359 cpu_relax();
363 static void ulite_console_putchar(struct uart_port *port, int ch)
365 ulite_console_wait_tx(port);
366 iowrite32be(ch, port->membase + ULITE_TX);
369 static void ulite_console_write(struct console *co, const char *s,
370 unsigned int count)
372 struct uart_port *port = &ulite_ports[co->index];
373 unsigned long flags;
374 unsigned int ier;
375 int locked = 1;
377 if (oops_in_progress) {
378 locked = spin_trylock_irqsave(&port->lock, flags);
379 } else
380 spin_lock_irqsave(&port->lock, flags);
382 /* save and disable interrupt */
383 ier = ioread32be(port->membase + ULITE_STATUS) & ULITE_STATUS_IE;
384 iowrite32be(0, port->membase + ULITE_CONTROL);
386 uart_console_write(port, s, count, ulite_console_putchar);
388 ulite_console_wait_tx(port);
390 /* restore interrupt state */
391 if (ier)
392 iowrite32be(ULITE_CONTROL_IE, port->membase + ULITE_CONTROL);
394 if (locked)
395 spin_unlock_irqrestore(&port->lock, flags);
398 static int __devinit ulite_console_setup(struct console *co, char *options)
400 struct uart_port *port;
401 int baud = 9600;
402 int bits = 8;
403 int parity = 'n';
404 int flow = 'n';
406 if (co->index < 0 || co->index >= ULITE_NR_UARTS)
407 return -EINVAL;
409 port = &ulite_ports[co->index];
411 /* Has the device been initialized yet? */
412 if (!port->mapbase) {
413 pr_debug("console on ttyUL%i not present\n", co->index);
414 return -ENODEV;
417 /* not initialized yet? */
418 if (!port->membase) {
419 if (ulite_request_port(port))
420 return -ENODEV;
423 if (options)
424 uart_parse_options(options, &baud, &parity, &bits, &flow);
426 return uart_set_options(port, co, baud, parity, bits, flow);
429 static struct uart_driver ulite_uart_driver;
431 static struct console ulite_console = {
432 .name = ULITE_NAME,
433 .write = ulite_console_write,
434 .device = uart_console_device,
435 .setup = ulite_console_setup,
436 .flags = CON_PRINTBUFFER,
437 .index = -1, /* Specified on the cmdline (e.g. console=ttyUL0 ) */
438 .data = &ulite_uart_driver,
441 static int __init ulite_console_init(void)
443 register_console(&ulite_console);
444 return 0;
447 console_initcall(ulite_console_init);
449 #endif /* CONFIG_SERIAL_UARTLITE_CONSOLE */
451 static struct uart_driver ulite_uart_driver = {
452 .owner = THIS_MODULE,
453 .driver_name = "uartlite",
454 .dev_name = ULITE_NAME,
455 .major = ULITE_MAJOR,
456 .minor = ULITE_MINOR,
457 .nr = ULITE_NR_UARTS,
458 #ifdef CONFIG_SERIAL_UARTLITE_CONSOLE
459 .cons = &ulite_console,
460 #endif
463 /* ---------------------------------------------------------------------
464 * Port assignment functions (mapping devices to uart_port structures)
467 /** ulite_assign: register a uartlite device with the driver
469 * @dev: pointer to device structure
470 * @id: requested id number. Pass -1 for automatic port assignment
471 * @base: base address of uartlite registers
472 * @irq: irq number for uartlite
474 * Returns: 0 on success, <0 otherwise
476 static int __devinit ulite_assign(struct device *dev, int id, u32 base, int irq)
478 struct uart_port *port;
479 int rc;
481 /* if id = -1; then scan for a free id and use that */
482 if (id < 0) {
483 for (id = 0; id < ULITE_NR_UARTS; id++)
484 if (ulite_ports[id].mapbase == 0)
485 break;
487 if (id < 0 || id >= ULITE_NR_UARTS) {
488 dev_err(dev, "%s%i too large\n", ULITE_NAME, id);
489 return -EINVAL;
492 if ((ulite_ports[id].mapbase) && (ulite_ports[id].mapbase != base)) {
493 dev_err(dev, "cannot assign to %s%i; it is already in use\n",
494 ULITE_NAME, id);
495 return -EBUSY;
498 port = &ulite_ports[id];
500 spin_lock_init(&port->lock);
501 port->fifosize = 16;
502 port->regshift = 2;
503 port->iotype = UPIO_MEM;
504 port->iobase = 1; /* mark port in use */
505 port->mapbase = base;
506 port->membase = NULL;
507 port->ops = &ulite_ops;
508 port->irq = irq;
509 port->flags = UPF_BOOT_AUTOCONF;
510 port->dev = dev;
511 port->type = PORT_UNKNOWN;
512 port->line = id;
514 dev_set_drvdata(dev, port);
516 /* Register the port */
517 rc = uart_add_one_port(&ulite_uart_driver, port);
518 if (rc) {
519 dev_err(dev, "uart_add_one_port() failed; err=%i\n", rc);
520 port->mapbase = 0;
521 dev_set_drvdata(dev, NULL);
522 return rc;
525 return 0;
528 /** ulite_release: register a uartlite device with the driver
530 * @dev: pointer to device structure
532 static int __devexit ulite_release(struct device *dev)
534 struct uart_port *port = dev_get_drvdata(dev);
535 int rc = 0;
537 if (port) {
538 rc = uart_remove_one_port(&ulite_uart_driver, port);
539 dev_set_drvdata(dev, NULL);
540 port->mapbase = 0;
543 return rc;
546 /* ---------------------------------------------------------------------
547 * Platform bus binding
550 static int __devinit ulite_probe(struct platform_device *pdev)
552 struct resource *res, *res2;
554 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
555 if (!res)
556 return -ENODEV;
558 res2 = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
559 if (!res2)
560 return -ENODEV;
562 return ulite_assign(&pdev->dev, pdev->id, res->start, res2->start);
565 static int __devexit ulite_remove(struct platform_device *pdev)
567 return ulite_release(&pdev->dev);
570 /* work with hotplug and coldplug */
571 MODULE_ALIAS("platform:uartlite");
573 static struct platform_driver ulite_platform_driver = {
574 .probe = ulite_probe,
575 .remove = __devexit_p(ulite_remove),
576 .driver = {
577 .owner = THIS_MODULE,
578 .name = "uartlite",
582 /* ---------------------------------------------------------------------
583 * OF bus bindings
585 #if defined(CONFIG_OF) && (defined(CONFIG_PPC32) || defined(CONFIG_MICROBLAZE))
586 static int __devinit
587 ulite_of_probe(struct platform_device *op, const struct of_device_id *match)
589 struct resource res;
590 const unsigned int *id;
591 int irq, rc;
593 dev_dbg(&op->dev, "%s(%p, %p)\n", __func__, op, match);
595 rc = of_address_to_resource(op->dev.of_node, 0, &res);
596 if (rc) {
597 dev_err(&op->dev, "invalid address\n");
598 return rc;
601 irq = irq_of_parse_and_map(op->dev.of_node, 0);
603 id = of_get_property(op->dev.of_node, "port-number", NULL);
605 return ulite_assign(&op->dev, id ? *id : -1, res.start, irq);
608 static int __devexit ulite_of_remove(struct platform_device *op)
610 return ulite_release(&op->dev);
613 static struct of_platform_driver ulite_of_driver = {
614 .probe = ulite_of_probe,
615 .remove = __devexit_p(ulite_of_remove),
616 .driver = {
617 .name = "uartlite",
618 .owner = THIS_MODULE,
619 .of_match_table = ulite_of_match,
623 /* Registration helpers to keep the number of #ifdefs to a minimum */
624 static inline int __init ulite_of_register(void)
626 pr_debug("uartlite: calling of_register_platform_driver()\n");
627 return of_register_platform_driver(&ulite_of_driver);
630 static inline void __exit ulite_of_unregister(void)
632 of_unregister_platform_driver(&ulite_of_driver);
634 #else /* CONFIG_OF && (CONFIG_PPC32 || CONFIG_MICROBLAZE) */
635 /* Appropriate config not enabled; do nothing helpers */
636 static inline int __init ulite_of_register(void) { return 0; }
637 static inline void __exit ulite_of_unregister(void) { }
638 #endif /* CONFIG_OF && (CONFIG_PPC32 || CONFIG_MICROBLAZE) */
640 /* ---------------------------------------------------------------------
641 * Module setup/teardown
644 int __init ulite_init(void)
646 int ret;
648 pr_debug("uartlite: calling uart_register_driver()\n");
649 ret = uart_register_driver(&ulite_uart_driver);
650 if (ret)
651 goto err_uart;
653 ret = ulite_of_register();
654 if (ret)
655 goto err_of;
657 pr_debug("uartlite: calling platform_driver_register()\n");
658 ret = platform_driver_register(&ulite_platform_driver);
659 if (ret)
660 goto err_plat;
662 return 0;
664 err_plat:
665 ulite_of_unregister();
666 err_of:
667 uart_unregister_driver(&ulite_uart_driver);
668 err_uart:
669 printk(KERN_ERR "registering uartlite driver failed: err=%i", ret);
670 return ret;
673 void __exit ulite_exit(void)
675 platform_driver_unregister(&ulite_platform_driver);
676 ulite_of_unregister();
677 uart_unregister_driver(&ulite_uart_driver);
680 module_init(ulite_init);
681 module_exit(ulite_exit);
683 MODULE_AUTHOR("Peter Korsgaard <jacmet@sunsite.dk>");
684 MODULE_DESCRIPTION("Xilinx uartlite serial driver");
685 MODULE_LICENSE("GPL");