Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/drivers/char/21285.c | |
3 | * | |
4 | * Driver for the serial port on the 21285 StrongArm-110 core logic chip. | |
5 | * | |
6 | * Based on drivers/char/serial.c | |
7 | * | |
8 | * $Id: 21285.c,v 1.37 2002/07/28 10:03:27 rmk Exp $ | |
9 | */ | |
10 | #include <linux/config.h> | |
11 | #include <linux/module.h> | |
12 | #include <linux/tty.h> | |
13 | #include <linux/ioport.h> | |
14 | #include <linux/init.h> | |
15 | #include <linux/console.h> | |
16 | #include <linux/device.h> | |
17 | #include <linux/tty_flip.h> | |
18 | #include <linux/serial_core.h> | |
19 | #include <linux/serial.h> | |
20 | ||
21 | #include <asm/io.h> | |
22 | #include <asm/irq.h> | |
23 | #include <asm/mach-types.h> | |
24 | #include <asm/hardware/dec21285.h> | |
25 | #include <asm/hardware.h> | |
26 | ||
27 | #define BAUD_BASE (mem_fclk_21285/64) | |
28 | ||
29 | #define SERIAL_21285_NAME "ttyFB" | |
30 | #define SERIAL_21285_MAJOR 204 | |
31 | #define SERIAL_21285_MINOR 4 | |
32 | ||
33 | #define RXSTAT_DUMMY_READ 0x80000000 | |
34 | #define RXSTAT_FRAME (1 << 0) | |
35 | #define RXSTAT_PARITY (1 << 1) | |
36 | #define RXSTAT_OVERRUN (1 << 2) | |
37 | #define RXSTAT_ANYERR (RXSTAT_FRAME|RXSTAT_PARITY|RXSTAT_OVERRUN) | |
38 | ||
39 | #define H_UBRLCR_BREAK (1 << 0) | |
40 | #define H_UBRLCR_PARENB (1 << 1) | |
41 | #define H_UBRLCR_PAREVN (1 << 2) | |
42 | #define H_UBRLCR_STOPB (1 << 3) | |
43 | #define H_UBRLCR_FIFO (1 << 4) | |
44 | ||
45 | static const char serial21285_name[] = "Footbridge UART"; | |
46 | ||
47 | #define tx_enabled(port) ((port)->unused[0]) | |
48 | #define rx_enabled(port) ((port)->unused[1]) | |
49 | ||
50 | /* | |
51 | * The documented expression for selecting the divisor is: | |
52 | * BAUD_BASE / baud - 1 | |
53 | * However, typically BAUD_BASE is not divisible by baud, so | |
54 | * we want to select the divisor that gives us the minimum | |
55 | * error. Therefore, we want: | |
56 | * int(BAUD_BASE / baud - 0.5) -> | |
57 | * int(BAUD_BASE / baud - (baud >> 1) / baud) -> | |
58 | * int((BAUD_BASE - (baud >> 1)) / baud) | |
59 | */ | |
60 | ||
61 | static void | |
62 | serial21285_stop_tx(struct uart_port *port, unsigned int tty_stop) | |
63 | { | |
64 | if (tx_enabled(port)) { | |
65 | disable_irq(IRQ_CONTX); | |
66 | tx_enabled(port) = 0; | |
67 | } | |
68 | } | |
69 | ||
70 | static void | |
71 | serial21285_start_tx(struct uart_port *port, unsigned int tty_start) | |
72 | { | |
73 | if (!tx_enabled(port)) { | |
74 | enable_irq(IRQ_CONTX); | |
75 | tx_enabled(port) = 1; | |
76 | } | |
77 | } | |
78 | ||
79 | static void serial21285_stop_rx(struct uart_port *port) | |
80 | { | |
81 | if (rx_enabled(port)) { | |
82 | disable_irq(IRQ_CONRX); | |
83 | rx_enabled(port) = 0; | |
84 | } | |
85 | } | |
86 | ||
87 | static void serial21285_enable_ms(struct uart_port *port) | |
88 | { | |
89 | } | |
90 | ||
91 | static irqreturn_t serial21285_rx_chars(int irq, void *dev_id, struct pt_regs *regs) | |
92 | { | |
93 | struct uart_port *port = dev_id; | |
94 | struct tty_struct *tty = port->info->tty; | |
95 | unsigned int status, ch, flag, rxs, max_count = 256; | |
96 | ||
97 | status = *CSR_UARTFLG; | |
98 | while (!(status & 0x10) && max_count--) { | |
99 | if (tty->flip.count >= TTY_FLIPBUF_SIZE) { | |
100 | if (tty->low_latency) | |
101 | tty_flip_buffer_push(tty); | |
102 | /* | |
103 | * If this failed then we will throw away the | |
104 | * bytes but must do so to clear interrupts | |
105 | */ | |
106 | } | |
107 | ||
108 | ch = *CSR_UARTDR; | |
109 | flag = TTY_NORMAL; | |
110 | port->icount.rx++; | |
111 | ||
112 | rxs = *CSR_RXSTAT | RXSTAT_DUMMY_READ; | |
45849282 | 113 | if (unlikely(rxs & RXSTAT_ANYERR)) { |
1da177e4 LT |
114 | if (rxs & RXSTAT_PARITY) |
115 | port->icount.parity++; | |
116 | else if (rxs & RXSTAT_FRAME) | |
117 | port->icount.frame++; | |
118 | if (rxs & RXSTAT_OVERRUN) | |
119 | port->icount.overrun++; | |
120 | ||
121 | rxs &= port->read_status_mask; | |
122 | ||
123 | if (rxs & RXSTAT_PARITY) | |
124 | flag = TTY_PARITY; | |
125 | else if (rxs & RXSTAT_FRAME) | |
126 | flag = TTY_FRAME; | |
127 | } | |
128 | ||
05ab3014 RK |
129 | uart_insert_char(port, rxs, RXSTAT_OVERRUN, ch, flag); |
130 | ||
1da177e4 LT |
131 | status = *CSR_UARTFLG; |
132 | } | |
133 | tty_flip_buffer_push(tty); | |
134 | ||
135 | return IRQ_HANDLED; | |
136 | } | |
137 | ||
138 | static irqreturn_t serial21285_tx_chars(int irq, void *dev_id, struct pt_regs *regs) | |
139 | { | |
140 | struct uart_port *port = dev_id; | |
141 | struct circ_buf *xmit = &port->info->xmit; | |
142 | int count = 256; | |
143 | ||
144 | if (port->x_char) { | |
145 | *CSR_UARTDR = port->x_char; | |
146 | port->icount.tx++; | |
147 | port->x_char = 0; | |
148 | goto out; | |
149 | } | |
150 | if (uart_circ_empty(xmit) || uart_tx_stopped(port)) { | |
151 | serial21285_stop_tx(port, 0); | |
152 | goto out; | |
153 | } | |
154 | ||
155 | do { | |
156 | *CSR_UARTDR = xmit->buf[xmit->tail]; | |
157 | xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); | |
158 | port->icount.tx++; | |
159 | if (uart_circ_empty(xmit)) | |
160 | break; | |
161 | } while (--count > 0 && !(*CSR_UARTFLG & 0x20)); | |
162 | ||
163 | if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) | |
164 | uart_write_wakeup(port); | |
165 | ||
166 | if (uart_circ_empty(xmit)) | |
167 | serial21285_stop_tx(port, 0); | |
168 | ||
169 | out: | |
170 | return IRQ_HANDLED; | |
171 | } | |
172 | ||
173 | static unsigned int serial21285_tx_empty(struct uart_port *port) | |
174 | { | |
175 | return (*CSR_UARTFLG & 8) ? 0 : TIOCSER_TEMT; | |
176 | } | |
177 | ||
178 | /* no modem control lines */ | |
179 | static unsigned int serial21285_get_mctrl(struct uart_port *port) | |
180 | { | |
181 | return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS; | |
182 | } | |
183 | ||
184 | static void serial21285_set_mctrl(struct uart_port *port, unsigned int mctrl) | |
185 | { | |
186 | } | |
187 | ||
188 | static void serial21285_break_ctl(struct uart_port *port, int break_state) | |
189 | { | |
190 | unsigned long flags; | |
191 | unsigned int h_lcr; | |
192 | ||
193 | spin_lock_irqsave(&port->lock, flags); | |
194 | h_lcr = *CSR_H_UBRLCR; | |
195 | if (break_state) | |
196 | h_lcr |= H_UBRLCR_BREAK; | |
197 | else | |
198 | h_lcr &= ~H_UBRLCR_BREAK; | |
199 | *CSR_H_UBRLCR = h_lcr; | |
200 | spin_unlock_irqrestore(&port->lock, flags); | |
201 | } | |
202 | ||
203 | static int serial21285_startup(struct uart_port *port) | |
204 | { | |
205 | int ret; | |
206 | ||
207 | tx_enabled(port) = 1; | |
208 | rx_enabled(port) = 1; | |
209 | ||
210 | ret = request_irq(IRQ_CONRX, serial21285_rx_chars, 0, | |
211 | serial21285_name, port); | |
212 | if (ret == 0) { | |
213 | ret = request_irq(IRQ_CONTX, serial21285_tx_chars, 0, | |
214 | serial21285_name, port); | |
215 | if (ret) | |
216 | free_irq(IRQ_CONRX, port); | |
217 | } | |
218 | ||
219 | return ret; | |
220 | } | |
221 | ||
222 | static void serial21285_shutdown(struct uart_port *port) | |
223 | { | |
224 | free_irq(IRQ_CONTX, port); | |
225 | free_irq(IRQ_CONRX, port); | |
226 | } | |
227 | ||
228 | static void | |
229 | serial21285_set_termios(struct uart_port *port, struct termios *termios, | |
230 | struct termios *old) | |
231 | { | |
232 | unsigned long flags; | |
233 | unsigned int baud, quot, h_lcr; | |
234 | ||
235 | /* | |
236 | * We don't support modem control lines. | |
237 | */ | |
238 | termios->c_cflag &= ~(HUPCL | CRTSCTS | CMSPAR); | |
239 | termios->c_cflag |= CLOCAL; | |
240 | ||
241 | /* | |
242 | * We don't support BREAK character recognition. | |
243 | */ | |
244 | termios->c_iflag &= ~(IGNBRK | BRKINT); | |
245 | ||
246 | /* | |
247 | * Ask the core to calculate the divisor for us. | |
248 | */ | |
249 | baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16); | |
250 | quot = uart_get_divisor(port, baud); | |
251 | ||
252 | switch (termios->c_cflag & CSIZE) { | |
253 | case CS5: | |
254 | h_lcr = 0x00; | |
255 | break; | |
256 | case CS6: | |
257 | h_lcr = 0x20; | |
258 | break; | |
259 | case CS7: | |
260 | h_lcr = 0x40; | |
261 | break; | |
262 | default: /* CS8 */ | |
263 | h_lcr = 0x60; | |
264 | break; | |
265 | } | |
266 | ||
267 | if (termios->c_cflag & CSTOPB) | |
268 | h_lcr |= H_UBRLCR_STOPB; | |
269 | if (termios->c_cflag & PARENB) { | |
270 | h_lcr |= H_UBRLCR_PARENB; | |
271 | if (!(termios->c_cflag & PARODD)) | |
272 | h_lcr |= H_UBRLCR_PAREVN; | |
273 | } | |
274 | ||
275 | if (port->fifosize) | |
276 | h_lcr |= H_UBRLCR_FIFO; | |
277 | ||
278 | spin_lock_irqsave(&port->lock, flags); | |
279 | ||
280 | /* | |
281 | * Update the per-port timeout. | |
282 | */ | |
283 | uart_update_timeout(port, termios->c_cflag, baud); | |
284 | ||
285 | /* | |
286 | * Which character status flags are we interested in? | |
287 | */ | |
288 | port->read_status_mask = RXSTAT_OVERRUN; | |
289 | if (termios->c_iflag & INPCK) | |
290 | port->read_status_mask |= RXSTAT_FRAME | RXSTAT_PARITY; | |
291 | ||
292 | /* | |
293 | * Which character status flags should we ignore? | |
294 | */ | |
295 | port->ignore_status_mask = 0; | |
296 | if (termios->c_iflag & IGNPAR) | |
297 | port->ignore_status_mask |= RXSTAT_FRAME | RXSTAT_PARITY; | |
298 | if (termios->c_iflag & IGNBRK && termios->c_iflag & IGNPAR) | |
299 | port->ignore_status_mask |= RXSTAT_OVERRUN; | |
300 | ||
301 | /* | |
302 | * Ignore all characters if CREAD is not set. | |
303 | */ | |
304 | if ((termios->c_cflag & CREAD) == 0) | |
305 | port->ignore_status_mask |= RXSTAT_DUMMY_READ; | |
306 | ||
307 | quot -= 1; | |
308 | ||
309 | *CSR_UARTCON = 0; | |
310 | *CSR_L_UBRLCR = quot & 0xff; | |
311 | *CSR_M_UBRLCR = (quot >> 8) & 0x0f; | |
312 | *CSR_H_UBRLCR = h_lcr; | |
313 | *CSR_UARTCON = 1; | |
314 | ||
315 | spin_unlock_irqrestore(&port->lock, flags); | |
316 | } | |
317 | ||
318 | static const char *serial21285_type(struct uart_port *port) | |
319 | { | |
320 | return port->type == PORT_21285 ? "DC21285" : NULL; | |
321 | } | |
322 | ||
323 | static void serial21285_release_port(struct uart_port *port) | |
324 | { | |
325 | release_mem_region(port->mapbase, 32); | |
326 | } | |
327 | ||
328 | static int serial21285_request_port(struct uart_port *port) | |
329 | { | |
330 | return request_mem_region(port->mapbase, 32, serial21285_name) | |
331 | != NULL ? 0 : -EBUSY; | |
332 | } | |
333 | ||
334 | static void serial21285_config_port(struct uart_port *port, int flags) | |
335 | { | |
336 | if (flags & UART_CONFIG_TYPE && serial21285_request_port(port) == 0) | |
337 | port->type = PORT_21285; | |
338 | } | |
339 | ||
340 | /* | |
341 | * verify the new serial_struct (for TIOCSSERIAL). | |
342 | */ | |
343 | static int serial21285_verify_port(struct uart_port *port, struct serial_struct *ser) | |
344 | { | |
345 | int ret = 0; | |
346 | if (ser->type != PORT_UNKNOWN && ser->type != PORT_21285) | |
347 | ret = -EINVAL; | |
348 | if (ser->irq != NO_IRQ) | |
349 | ret = -EINVAL; | |
350 | if (ser->baud_base != port->uartclk / 16) | |
351 | ret = -EINVAL; | |
352 | return ret; | |
353 | } | |
354 | ||
355 | static struct uart_ops serial21285_ops = { | |
356 | .tx_empty = serial21285_tx_empty, | |
357 | .get_mctrl = serial21285_get_mctrl, | |
358 | .set_mctrl = serial21285_set_mctrl, | |
359 | .stop_tx = serial21285_stop_tx, | |
360 | .start_tx = serial21285_start_tx, | |
361 | .stop_rx = serial21285_stop_rx, | |
362 | .enable_ms = serial21285_enable_ms, | |
363 | .break_ctl = serial21285_break_ctl, | |
364 | .startup = serial21285_startup, | |
365 | .shutdown = serial21285_shutdown, | |
366 | .set_termios = serial21285_set_termios, | |
367 | .type = serial21285_type, | |
368 | .release_port = serial21285_release_port, | |
369 | .request_port = serial21285_request_port, | |
370 | .config_port = serial21285_config_port, | |
371 | .verify_port = serial21285_verify_port, | |
372 | }; | |
373 | ||
374 | static struct uart_port serial21285_port = { | |
375 | .mapbase = 0x42000160, | |
376 | .iotype = SERIAL_IO_MEM, | |
377 | .irq = NO_IRQ, | |
378 | .fifosize = 16, | |
379 | .ops = &serial21285_ops, | |
380 | .flags = ASYNC_BOOT_AUTOCONF, | |
381 | }; | |
382 | ||
383 | static void serial21285_setup_ports(void) | |
384 | { | |
385 | serial21285_port.uartclk = mem_fclk_21285 / 4; | |
386 | } | |
387 | ||
388 | #ifdef CONFIG_SERIAL_21285_CONSOLE | |
389 | ||
390 | static void | |
391 | serial21285_console_write(struct console *co, const char *s, | |
392 | unsigned int count) | |
393 | { | |
394 | int i; | |
395 | ||
396 | for (i = 0; i < count; i++) { | |
397 | while (*CSR_UARTFLG & 0x20) | |
398 | barrier(); | |
399 | *CSR_UARTDR = s[i]; | |
400 | if (s[i] == '\n') { | |
401 | while (*CSR_UARTFLG & 0x20) | |
402 | barrier(); | |
403 | *CSR_UARTDR = '\r'; | |
404 | } | |
405 | } | |
406 | } | |
407 | ||
408 | static void __init | |
409 | serial21285_get_options(struct uart_port *port, int *baud, | |
410 | int *parity, int *bits) | |
411 | { | |
412 | if (*CSR_UARTCON == 1) { | |
413 | unsigned int tmp; | |
414 | ||
415 | tmp = *CSR_H_UBRLCR; | |
416 | switch (tmp & 0x60) { | |
417 | case 0x00: | |
418 | *bits = 5; | |
419 | break; | |
420 | case 0x20: | |
421 | *bits = 6; | |
422 | break; | |
423 | case 0x40: | |
424 | *bits = 7; | |
425 | break; | |
426 | default: | |
427 | case 0x60: | |
428 | *bits = 8; | |
429 | break; | |
430 | } | |
431 | ||
432 | if (tmp & H_UBRLCR_PARENB) { | |
433 | *parity = 'o'; | |
434 | if (tmp & H_UBRLCR_PAREVN) | |
435 | *parity = 'e'; | |
436 | } | |
437 | ||
438 | tmp = *CSR_L_UBRLCR | (*CSR_M_UBRLCR << 8); | |
439 | ||
440 | *baud = port->uartclk / (16 * (tmp + 1)); | |
441 | } | |
442 | } | |
443 | ||
444 | static int __init serial21285_console_setup(struct console *co, char *options) | |
445 | { | |
446 | struct uart_port *port = &serial21285_port; | |
447 | int baud = 9600; | |
448 | int bits = 8; | |
449 | int parity = 'n'; | |
450 | int flow = 'n'; | |
451 | ||
452 | if (machine_is_personal_server()) | |
453 | baud = 57600; | |
454 | ||
455 | /* | |
456 | * Check whether an invalid uart number has been specified, and | |
457 | * if so, search for the first available port that does have | |
458 | * console support. | |
459 | */ | |
460 | if (options) | |
461 | uart_parse_options(options, &baud, &parity, &bits, &flow); | |
462 | else | |
463 | serial21285_get_options(port, &baud, &parity, &bits); | |
464 | ||
465 | return uart_set_options(port, co, baud, parity, bits, flow); | |
466 | } | |
467 | ||
468 | extern struct uart_driver serial21285_reg; | |
469 | ||
470 | static struct console serial21285_console = | |
471 | { | |
472 | .name = SERIAL_21285_NAME, | |
473 | .write = serial21285_console_write, | |
474 | .device = uart_console_device, | |
475 | .setup = serial21285_console_setup, | |
476 | .flags = CON_PRINTBUFFER, | |
477 | .index = -1, | |
478 | .data = &serial21285_reg, | |
479 | }; | |
480 | ||
481 | static int __init rs285_console_init(void) | |
482 | { | |
483 | serial21285_setup_ports(); | |
484 | register_console(&serial21285_console); | |
485 | return 0; | |
486 | } | |
487 | console_initcall(rs285_console_init); | |
488 | ||
489 | #define SERIAL_21285_CONSOLE &serial21285_console | |
490 | #else | |
491 | #define SERIAL_21285_CONSOLE NULL | |
492 | #endif | |
493 | ||
494 | static struct uart_driver serial21285_reg = { | |
495 | .owner = THIS_MODULE, | |
496 | .driver_name = "ttyFB", | |
497 | .dev_name = "ttyFB", | |
498 | .devfs_name = "ttyFB", | |
499 | .major = SERIAL_21285_MAJOR, | |
500 | .minor = SERIAL_21285_MINOR, | |
501 | .nr = 1, | |
502 | .cons = SERIAL_21285_CONSOLE, | |
503 | }; | |
504 | ||
505 | static int __init serial21285_init(void) | |
506 | { | |
507 | int ret; | |
508 | ||
509 | printk(KERN_INFO "Serial: 21285 driver $Revision: 1.37 $\n"); | |
510 | ||
511 | serial21285_setup_ports(); | |
512 | ||
513 | ret = uart_register_driver(&serial21285_reg); | |
514 | if (ret == 0) | |
515 | uart_add_one_port(&serial21285_reg, &serial21285_port); | |
516 | ||
517 | return ret; | |
518 | } | |
519 | ||
520 | static void __exit serial21285_exit(void) | |
521 | { | |
522 | uart_remove_one_port(&serial21285_reg, &serial21285_port); | |
523 | uart_unregister_driver(&serial21285_reg); | |
524 | } | |
525 | ||
526 | module_init(serial21285_init); | |
527 | module_exit(serial21285_exit); | |
528 | ||
529 | MODULE_LICENSE("GPL"); | |
530 | MODULE_DESCRIPTION("Intel Footbridge (21285) serial driver $Revision: 1.37 $"); | |
531 | MODULE_ALIAS_CHARDEV(SERIAL_21285_MAJOR, SERIAL_21285_MINOR); |