- TTY: serial, cleanup include file (bnc#881571).
[opensuse:kernel.git] / drivers / tty / serial / uartlite.c
1 /*
2  * uartlite.c: Serial driver for Xilinx uartlite serial controller
3  *
4  * Copyright (C) 2006 Peter Korsgaard <jacmet@sunsite.dk>
5  * Copyright (C) 2007 Secret Lab Technologies Ltd.
6  *
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.
10  */
11
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/tty_flip.h>
19 #include <linux/delay.h>
20 #include <linux/interrupt.h>
21 #include <linux/init.h>
22 #include <asm/io.h>
23 #include <linux/of.h>
24 #include <linux/of_address.h>
25 #include <linux/of_device.h>
26 #include <linux/of_platform.h>
27
28 #define ULITE_NAME              "ttyUL"
29 #define ULITE_MAJOR             204
30 #define ULITE_MINOR             187
31 #define ULITE_NR_UARTS          4
32
33 /* ---------------------------------------------------------------------
34  * Register definitions
35  *
36  * For register details see datasheet:
37  * http://www.xilinx.com/support/documentation/ip_documentation/opb_uartlite.pdf 
38  */
39
40 #define ULITE_RX                0x00
41 #define ULITE_TX                0x04
42 #define ULITE_STATUS            0x08
43 #define ULITE_CONTROL           0x0c
44
45 #define ULITE_REGION            16
46
47 #define ULITE_STATUS_RXVALID    0x01
48 #define ULITE_STATUS_RXFULL     0x02
49 #define ULITE_STATUS_TXEMPTY    0x04
50 #define ULITE_STATUS_TXFULL     0x08
51 #define ULITE_STATUS_IE         0x10
52 #define ULITE_STATUS_OVERRUN    0x20
53 #define ULITE_STATUS_FRAME      0x40
54 #define ULITE_STATUS_PARITY     0x80
55
56 #define ULITE_CONTROL_RST_TX    0x01
57 #define ULITE_CONTROL_RST_RX    0x02
58 #define ULITE_CONTROL_IE        0x10
59
60
61 static struct uart_port ulite_ports[ULITE_NR_UARTS];
62
63 /* ---------------------------------------------------------------------
64  * Core UART driver operations
65  */
66
67 static int ulite_receive(struct uart_port *port, int stat)
68 {
69         struct tty_struct *tty = port->state->port.tty;
70         unsigned char ch = 0;
71         char flag = TTY_NORMAL;
72
73         if ((stat & (ULITE_STATUS_RXVALID | ULITE_STATUS_OVERRUN
74                      | ULITE_STATUS_FRAME)) == 0)
75                 return 0;
76
77         /* stats */
78         if (stat & ULITE_STATUS_RXVALID) {
79                 port->icount.rx++;
80                 ch = ioread32be(port->membase + ULITE_RX);
81
82                 if (stat & ULITE_STATUS_PARITY)
83                         port->icount.parity++;
84         }
85
86         if (stat & ULITE_STATUS_OVERRUN)
87                 port->icount.overrun++;
88
89         if (stat & ULITE_STATUS_FRAME)
90                 port->icount.frame++;
91
92
93         /* drop byte with parity error if IGNPAR specificed */
94         if (stat & port->ignore_status_mask & ULITE_STATUS_PARITY)
95                 stat &= ~ULITE_STATUS_RXVALID;
96
97         stat &= port->read_status_mask;
98
99         if (stat & ULITE_STATUS_PARITY)
100                 flag = TTY_PARITY;
101
102
103         stat &= ~port->ignore_status_mask;
104
105         if (stat & ULITE_STATUS_RXVALID)
106                 tty_insert_flip_char(tty, ch, flag);
107
108         if (stat & ULITE_STATUS_FRAME)
109                 tty_insert_flip_char(tty, 0, TTY_FRAME);
110
111         if (stat & ULITE_STATUS_OVERRUN)
112                 tty_insert_flip_char(tty, 0, TTY_OVERRUN);
113
114         return 1;
115 }
116
117 static int ulite_transmit(struct uart_port *port, int stat)
118 {
119         struct circ_buf *xmit  = &port->state->xmit;
120
121         if (stat & ULITE_STATUS_TXFULL)
122                 return 0;
123
124         if (port->x_char) {
125                 iowrite32be(port->x_char, port->membase + ULITE_TX);
126                 port->x_char = 0;
127                 port->icount.tx++;
128                 return 1;
129         }
130
131         if (uart_circ_empty(xmit) || uart_tx_stopped(port))
132                 return 0;
133
134         iowrite32be(xmit->buf[xmit->tail], port->membase + ULITE_TX);
135         xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE-1);
136         port->icount.tx++;
137
138         /* wake up */
139         if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
140                 uart_write_wakeup(port);
141
142         return 1;
143 }
144
145 static irqreturn_t ulite_isr(int irq, void *dev_id)
146 {
147         struct uart_port *port = dev_id;
148         int busy, n = 0;
149
150         do {
151                 int stat = ioread32be(port->membase + ULITE_STATUS);
152                 busy  = ulite_receive(port, stat);
153                 busy |= ulite_transmit(port, stat);
154                 n++;
155         } while (busy);
156
157         /* work done? */
158         if (n > 1) {
159                 tty_flip_buffer_push(port->state->port.tty);
160                 return IRQ_HANDLED;
161         } else {
162                 return IRQ_NONE;
163         }
164 }
165
166 static unsigned int ulite_tx_empty(struct uart_port *port)
167 {
168         unsigned long flags;
169         unsigned int ret;
170
171         spin_lock_irqsave(&port->lock, flags);
172         ret = ioread32be(port->membase + ULITE_STATUS);
173         spin_unlock_irqrestore(&port->lock, flags);
174
175         return ret & ULITE_STATUS_TXEMPTY ? TIOCSER_TEMT : 0;
176 }
177
178 static unsigned int ulite_get_mctrl(struct uart_port *port)
179 {
180         return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
181 }
182
183 static void ulite_set_mctrl(struct uart_port *port, unsigned int mctrl)
184 {
185         /* N/A */
186 }
187
188 static void ulite_stop_tx(struct uart_port *port)
189 {
190         /* N/A */
191 }
192
193 static void ulite_start_tx(struct uart_port *port)
194 {
195         ulite_transmit(port, ioread32be(port->membase + ULITE_STATUS));
196 }
197
198 static void ulite_stop_rx(struct uart_port *port)
199 {
200         /* don't forward any more data (like !CREAD) */
201         port->ignore_status_mask = ULITE_STATUS_RXVALID | ULITE_STATUS_PARITY
202                 | ULITE_STATUS_FRAME | ULITE_STATUS_OVERRUN;
203 }
204
205 static void ulite_enable_ms(struct uart_port *port)
206 {
207         /* N/A */
208 }
209
210 static void ulite_break_ctl(struct uart_port *port, int ctl)
211 {
212         /* N/A */
213 }
214
215 static int ulite_startup(struct uart_port *port)
216 {
217         int ret;
218
219         ret = request_irq(port->irq, ulite_isr,
220                           IRQF_SHARED | IRQF_SAMPLE_RANDOM, "uartlite", port);
221         if (ret)
222                 return ret;
223
224         iowrite32be(ULITE_CONTROL_RST_RX | ULITE_CONTROL_RST_TX,
225                port->membase + ULITE_CONTROL);
226         iowrite32be(ULITE_CONTROL_IE, port->membase + ULITE_CONTROL);
227
228         return 0;
229 }
230
231 static void ulite_shutdown(struct uart_port *port)
232 {
233         iowrite32be(0, port->membase + ULITE_CONTROL);
234         ioread32be(port->membase + ULITE_CONTROL); /* dummy */
235         free_irq(port->irq, port);
236 }
237
238 static void ulite_set_termios(struct uart_port *port, struct ktermios *termios,
239                               struct ktermios *old)
240 {
241         unsigned long flags;
242         unsigned int baud;
243
244         spin_lock_irqsave(&port->lock, flags);
245
246         port->read_status_mask = ULITE_STATUS_RXVALID | ULITE_STATUS_OVERRUN
247                 | ULITE_STATUS_TXFULL;
248
249         if (termios->c_iflag & INPCK)
250                 port->read_status_mask |=
251                         ULITE_STATUS_PARITY | ULITE_STATUS_FRAME;
252
253         port->ignore_status_mask = 0;
254         if (termios->c_iflag & IGNPAR)
255                 port->ignore_status_mask |= ULITE_STATUS_PARITY
256                         | ULITE_STATUS_FRAME | ULITE_STATUS_OVERRUN;
257
258         /* ignore all characters if CREAD is not set */
259         if ((termios->c_cflag & CREAD) == 0)
260                 port->ignore_status_mask |=
261                         ULITE_STATUS_RXVALID | ULITE_STATUS_PARITY
262                         | ULITE_STATUS_FRAME | ULITE_STATUS_OVERRUN;
263
264         /* update timeout */
265         baud = uart_get_baud_rate(port, termios, old, 0, 460800);
266         uart_update_timeout(port, termios->c_cflag, baud);
267
268         spin_unlock_irqrestore(&port->lock, flags);
269 }
270
271 static const char *ulite_type(struct uart_port *port)
272 {
273         return port->type == PORT_UARTLITE ? "uartlite" : NULL;
274 }
275
276 static void ulite_release_port(struct uart_port *port)
277 {
278         release_mem_region(port->mapbase, ULITE_REGION);
279         iounmap(port->membase);
280         port->membase = NULL;
281 }
282
283 static int ulite_request_port(struct uart_port *port)
284 {
285         pr_debug("ulite console: port=%p; port->mapbase=%llx\n",
286                  port, (unsigned long long) port->mapbase);
287
288         if (!request_mem_region(port->mapbase, ULITE_REGION, "uartlite")) {
289                 dev_err(port->dev, "Memory region busy\n");
290                 return -EBUSY;
291         }
292
293         port->membase = ioremap(port->mapbase, ULITE_REGION);
294         if (!port->membase) {
295                 dev_err(port->dev, "Unable to map registers\n");
296                 release_mem_region(port->mapbase, ULITE_REGION);
297                 return -EBUSY;
298         }
299
300         return 0;
301 }
302
303 static void ulite_config_port(struct uart_port *port, int flags)
304 {
305         if (!ulite_request_port(port))
306                 port->type = PORT_UARTLITE;
307 }
308
309 static int ulite_verify_port(struct uart_port *port, struct serial_struct *ser)
310 {
311         /* we don't want the core code to modify any port params */
312         return -EINVAL;
313 }
314
315 #ifdef CONFIG_CONSOLE_POLL
316 static int ulite_get_poll_char(struct uart_port *port)
317 {
318         if (!(ioread32be(port->membase + ULITE_STATUS)
319                                                 & ULITE_STATUS_RXVALID))
320                 return NO_POLL_CHAR;
321
322         return ioread32be(port->membase + ULITE_RX);
323 }
324
325 static void ulite_put_poll_char(struct uart_port *port, unsigned char ch)
326 {
327         while (ioread32be(port->membase + ULITE_STATUS) & ULITE_STATUS_TXFULL)
328                 cpu_relax();
329
330         /* write char to device */
331         iowrite32be(ch, port->membase + ULITE_TX);
332 }
333 #endif
334
335 static struct uart_ops ulite_ops = {
336         .tx_empty       = ulite_tx_empty,
337         .set_mctrl      = ulite_set_mctrl,
338         .get_mctrl      = ulite_get_mctrl,
339         .stop_tx        = ulite_stop_tx,
340         .start_tx       = ulite_start_tx,
341         .stop_rx        = ulite_stop_rx,
342         .enable_ms      = ulite_enable_ms,
343         .break_ctl      = ulite_break_ctl,
344         .startup        = ulite_startup,
345         .shutdown       = ulite_shutdown,
346         .set_termios    = ulite_set_termios,
347         .type           = ulite_type,
348         .release_port   = ulite_release_port,
349         .request_port   = ulite_request_port,
350         .config_port    = ulite_config_port,
351         .verify_port    = ulite_verify_port,
352 #ifdef CONFIG_CONSOLE_POLL
353         .poll_get_char  = ulite_get_poll_char,
354         .poll_put_char  = ulite_put_poll_char,
355 #endif
356 };
357
358 /* ---------------------------------------------------------------------
359  * Console driver operations
360  */
361
362 #ifdef CONFIG_SERIAL_UARTLITE_CONSOLE
363 static void ulite_console_wait_tx(struct uart_port *port)
364 {
365         int i;
366         u8 val;
367
368         /* Spin waiting for TX fifo to have space available */
369         for (i = 0; i < 100000; i++) {
370                 val = ioread32be(port->membase + ULITE_STATUS);
371                 if ((val & ULITE_STATUS_TXFULL) == 0)
372                         break;
373                 cpu_relax();
374         }
375 }
376
377 static void ulite_console_putchar(struct uart_port *port, int ch)
378 {
379         ulite_console_wait_tx(port);
380         iowrite32be(ch, port->membase + ULITE_TX);
381 }
382
383 static void ulite_console_write(struct console *co, const char *s,
384                                 unsigned int count)
385 {
386         struct uart_port *port = &ulite_ports[co->index];
387         unsigned long flags;
388         unsigned int ier;
389         int locked = 1;
390
391         if (oops_in_progress) {
392                 locked = spin_trylock_irqsave(&port->lock, flags);
393         } else
394                 spin_lock_irqsave(&port->lock, flags);
395
396         /* save and disable interrupt */
397         ier = ioread32be(port->membase + ULITE_STATUS) & ULITE_STATUS_IE;
398         iowrite32be(0, port->membase + ULITE_CONTROL);
399
400         uart_console_write(port, s, count, ulite_console_putchar);
401
402         ulite_console_wait_tx(port);
403
404         /* restore interrupt state */
405         if (ier)
406                 iowrite32be(ULITE_CONTROL_IE, port->membase + ULITE_CONTROL);
407
408         if (locked)
409                 spin_unlock_irqrestore(&port->lock, flags);
410 }
411
412 static int __devinit ulite_console_setup(struct console *co, char *options)
413 {
414         struct uart_port *port;
415         int baud = 9600;
416         int bits = 8;
417         int parity = 'n';
418         int flow = 'n';
419
420         if (co->index < 0 || co->index >= ULITE_NR_UARTS)
421                 return -EINVAL;
422
423         port = &ulite_ports[co->index];
424
425         /* Has the device been initialized yet? */
426         if (!port->mapbase) {
427                 pr_debug("console on ttyUL%i not present\n", co->index);
428                 return -ENODEV;
429         }
430
431         /* not initialized yet? */
432         if (!port->membase) {
433                 if (ulite_request_port(port))
434                         return -ENODEV;
435         }
436
437         if (options)
438                 uart_parse_options(options, &baud, &parity, &bits, &flow);
439
440         return uart_set_options(port, co, baud, parity, bits, flow);
441 }
442
443 static struct uart_driver ulite_uart_driver;
444
445 static struct console ulite_console = {
446         .name   = ULITE_NAME,
447         .write  = ulite_console_write,
448         .device = uart_console_device,
449         .setup  = ulite_console_setup,
450         .flags  = CON_PRINTBUFFER,
451         .index  = -1, /* Specified on the cmdline (e.g. console=ttyUL0 ) */
452         .data   = &ulite_uart_driver,
453 };
454
455 static int __init ulite_console_init(void)
456 {
457         register_console(&ulite_console);
458         return 0;
459 }
460
461 console_initcall(ulite_console_init);
462
463 #endif /* CONFIG_SERIAL_UARTLITE_CONSOLE */
464
465 static struct uart_driver ulite_uart_driver = {
466         .owner          = THIS_MODULE,
467         .driver_name    = "uartlite",
468         .dev_name       = ULITE_NAME,
469         .major          = ULITE_MAJOR,
470         .minor          = ULITE_MINOR,
471         .nr             = ULITE_NR_UARTS,
472 #ifdef CONFIG_SERIAL_UARTLITE_CONSOLE
473         .cons           = &ulite_console,
474 #endif
475 };
476
477 /* ---------------------------------------------------------------------
478  * Port assignment functions (mapping devices to uart_port structures)
479  */
480
481 /** ulite_assign: register a uartlite device with the driver
482  *
483  * @dev: pointer to device structure
484  * @id: requested id number.  Pass -1 for automatic port assignment
485  * @base: base address of uartlite registers
486  * @irq: irq number for uartlite
487  *
488  * Returns: 0 on success, <0 otherwise
489  */
490 static int __devinit ulite_assign(struct device *dev, int id, u32 base, int irq)
491 {
492         struct uart_port *port;
493         int rc;
494
495         /* if id = -1; then scan for a free id and use that */
496         if (id < 0) {
497                 for (id = 0; id < ULITE_NR_UARTS; id++)
498                         if (ulite_ports[id].mapbase == 0)
499                                 break;
500         }
501         if (id < 0 || id >= ULITE_NR_UARTS) {
502                 dev_err(dev, "%s%i too large\n", ULITE_NAME, id);
503                 return -EINVAL;
504         }
505
506         if ((ulite_ports[id].mapbase) && (ulite_ports[id].mapbase != base)) {
507                 dev_err(dev, "cannot assign to %s%i; it is already in use\n",
508                         ULITE_NAME, id);
509                 return -EBUSY;
510         }
511
512         port = &ulite_ports[id];
513
514         spin_lock_init(&port->lock);
515         port->fifosize = 16;
516         port->regshift = 2;
517         port->iotype = UPIO_MEM;
518         port->iobase = 1; /* mark port in use */
519         port->mapbase = base;
520         port->membase = NULL;
521         port->ops = &ulite_ops;
522         port->irq = irq;
523         port->flags = UPF_BOOT_AUTOCONF;
524         port->dev = dev;
525         port->type = PORT_UNKNOWN;
526         port->line = id;
527
528         dev_set_drvdata(dev, port);
529
530         /* Register the port */
531         rc = uart_add_one_port(&ulite_uart_driver, port);
532         if (rc) {
533                 dev_err(dev, "uart_add_one_port() failed; err=%i\n", rc);
534                 port->mapbase = 0;
535                 dev_set_drvdata(dev, NULL);
536                 return rc;
537         }
538
539         return 0;
540 }
541
542 /** ulite_release: register a uartlite device with the driver
543  *
544  * @dev: pointer to device structure
545  */
546 static int __devexit ulite_release(struct device *dev)
547 {
548         struct uart_port *port = dev_get_drvdata(dev);
549         int rc = 0;
550
551         if (port) {
552                 rc = uart_remove_one_port(&ulite_uart_driver, port);
553                 dev_set_drvdata(dev, NULL);
554                 port->mapbase = 0;
555         }
556
557         return rc;
558 }
559
560 /* ---------------------------------------------------------------------
561  * Platform bus binding
562  */
563
564 #if defined(CONFIG_OF)
565 /* Match table for of_platform binding */
566 static struct of_device_id ulite_of_match[] __devinitdata = {
567         { .compatible = "xlnx,opb-uartlite-1.00.b", },
568         { .compatible = "xlnx,xps-uartlite-1.00.a", },
569         {}
570 };
571 MODULE_DEVICE_TABLE(of, ulite_of_match);
572 #else /* CONFIG_OF */
573 #define ulite_of_match NULL
574 #endif /* CONFIG_OF */
575
576 static int __devinit ulite_probe(struct platform_device *pdev)
577 {
578         struct resource *res, *res2;
579         int id = pdev->id;
580 #ifdef CONFIG_OF
581         const __be32 *prop;
582
583         prop = of_get_property(pdev->dev.of_node, "port-number", NULL);
584         if (prop)
585                 id = be32_to_cpup(prop);
586 #endif
587
588         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
589         if (!res)
590                 return -ENODEV;
591
592         res2 = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
593         if (!res2)
594                 return -ENODEV;
595
596         return ulite_assign(&pdev->dev, id, res->start, res2->start);
597 }
598
599 static int __devexit ulite_remove(struct platform_device *pdev)
600 {
601         return ulite_release(&pdev->dev);
602 }
603
604 /* work with hotplug and coldplug */
605 MODULE_ALIAS("platform:uartlite");
606
607 static struct platform_driver ulite_platform_driver = {
608         .probe = ulite_probe,
609         .remove = __devexit_p(ulite_remove),
610         .driver = {
611                 .owner = THIS_MODULE,
612                 .name  = "uartlite",
613                 .of_match_table = ulite_of_match,
614         },
615 };
616
617 /* ---------------------------------------------------------------------
618  * Module setup/teardown
619  */
620
621 int __init ulite_init(void)
622 {
623         int ret;
624
625         pr_debug("uartlite: calling uart_register_driver()\n");
626         ret = uart_register_driver(&ulite_uart_driver);
627         if (ret)
628                 goto err_uart;
629
630         pr_debug("uartlite: calling platform_driver_register()\n");
631         ret = platform_driver_register(&ulite_platform_driver);
632         if (ret)
633                 goto err_plat;
634
635         return 0;
636
637 err_plat:
638         uart_unregister_driver(&ulite_uart_driver);
639 err_uart:
640         printk(KERN_ERR "registering uartlite driver failed: err=%i", ret);
641         return ret;
642 }
643
644 void __exit ulite_exit(void)
645 {
646         platform_driver_unregister(&ulite_platform_driver);
647         uart_unregister_driver(&ulite_uart_driver);
648 }
649
650 module_init(ulite_init);
651 module_exit(ulite_exit);
652
653 MODULE_AUTHOR("Peter Korsgaard <jacmet@sunsite.dk>");
654 MODULE_DESCRIPTION("Xilinx uartlite serial driver");
655 MODULE_LICENSE("GPL");