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Commit | Line | Data |
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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 | ||
b129a8cc | 61 | static void serial21285_stop_tx(struct uart_port *port) |
1da177e4 LT |
62 | { |
63 | if (tx_enabled(port)) { | |
64 | disable_irq(IRQ_CONTX); | |
65 | tx_enabled(port) = 0; | |
66 | } | |
67 | } | |
68 | ||
b129a8cc | 69 | static void serial21285_start_tx(struct uart_port *port) |
1da177e4 LT |
70 | { |
71 | if (!tx_enabled(port)) { | |
72 | enable_irq(IRQ_CONTX); | |
73 | tx_enabled(port) = 1; | |
74 | } | |
75 | } | |
76 | ||
77 | static void serial21285_stop_rx(struct uart_port *port) | |
78 | { | |
79 | if (rx_enabled(port)) { | |
80 | disable_irq(IRQ_CONRX); | |
81 | rx_enabled(port) = 0; | |
82 | } | |
83 | } | |
84 | ||
85 | static void serial21285_enable_ms(struct uart_port *port) | |
86 | { | |
87 | } | |
88 | ||
89 | static irqreturn_t serial21285_rx_chars(int irq, void *dev_id, struct pt_regs *regs) | |
90 | { | |
91 | struct uart_port *port = dev_id; | |
92 | struct tty_struct *tty = port->info->tty; | |
93 | unsigned int status, ch, flag, rxs, max_count = 256; | |
94 | ||
95 | status = *CSR_UARTFLG; | |
96 | while (!(status & 0x10) && max_count--) { | |
97 | if (tty->flip.count >= TTY_FLIPBUF_SIZE) { | |
98 | if (tty->low_latency) | |
99 | tty_flip_buffer_push(tty); | |
100 | /* | |
101 | * If this failed then we will throw away the | |
102 | * bytes but must do so to clear interrupts | |
103 | */ | |
104 | } | |
105 | ||
106 | ch = *CSR_UARTDR; | |
107 | flag = TTY_NORMAL; | |
108 | port->icount.rx++; | |
109 | ||
110 | rxs = *CSR_RXSTAT | RXSTAT_DUMMY_READ; | |
45849282 | 111 | if (unlikely(rxs & RXSTAT_ANYERR)) { |
1da177e4 LT |
112 | if (rxs & RXSTAT_PARITY) |
113 | port->icount.parity++; | |
114 | else if (rxs & RXSTAT_FRAME) | |
115 | port->icount.frame++; | |
116 | if (rxs & RXSTAT_OVERRUN) | |
117 | port->icount.overrun++; | |
118 | ||
119 | rxs &= port->read_status_mask; | |
120 | ||
121 | if (rxs & RXSTAT_PARITY) | |
122 | flag = TTY_PARITY; | |
123 | else if (rxs & RXSTAT_FRAME) | |
124 | flag = TTY_FRAME; | |
125 | } | |
126 | ||
05ab3014 RK |
127 | uart_insert_char(port, rxs, RXSTAT_OVERRUN, ch, flag); |
128 | ||
1da177e4 LT |
129 | status = *CSR_UARTFLG; |
130 | } | |
131 | tty_flip_buffer_push(tty); | |
132 | ||
133 | return IRQ_HANDLED; | |
134 | } | |
135 | ||
136 | static irqreturn_t serial21285_tx_chars(int irq, void *dev_id, struct pt_regs *regs) | |
137 | { | |
138 | struct uart_port *port = dev_id; | |
139 | struct circ_buf *xmit = &port->info->xmit; | |
140 | int count = 256; | |
141 | ||
142 | if (port->x_char) { | |
143 | *CSR_UARTDR = port->x_char; | |
144 | port->icount.tx++; | |
145 | port->x_char = 0; | |
146 | goto out; | |
147 | } | |
148 | if (uart_circ_empty(xmit) || uart_tx_stopped(port)) { | |
b129a8cc | 149 | serial21285_stop_tx(port); |
1da177e4 LT |
150 | goto out; |
151 | } | |
152 | ||
153 | do { | |
154 | *CSR_UARTDR = xmit->buf[xmit->tail]; | |
155 | xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); | |
156 | port->icount.tx++; | |
157 | if (uart_circ_empty(xmit)) | |
158 | break; | |
159 | } while (--count > 0 && !(*CSR_UARTFLG & 0x20)); | |
160 | ||
161 | if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) | |
162 | uart_write_wakeup(port); | |
163 | ||
164 | if (uart_circ_empty(xmit)) | |
b129a8cc | 165 | serial21285_stop_tx(port); |
1da177e4 LT |
166 | |
167 | out: | |
168 | return IRQ_HANDLED; | |
169 | } | |
170 | ||
171 | static unsigned int serial21285_tx_empty(struct uart_port *port) | |
172 | { | |
173 | return (*CSR_UARTFLG & 8) ? 0 : TIOCSER_TEMT; | |
174 | } | |
175 | ||
176 | /* no modem control lines */ | |
177 | static unsigned int serial21285_get_mctrl(struct uart_port *port) | |
178 | { | |
179 | return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS; | |
180 | } | |
181 | ||
182 | static void serial21285_set_mctrl(struct uart_port *port, unsigned int mctrl) | |
183 | { | |
184 | } | |
185 | ||
186 | static void serial21285_break_ctl(struct uart_port *port, int break_state) | |
187 | { | |
188 | unsigned long flags; | |
189 | unsigned int h_lcr; | |
190 | ||
191 | spin_lock_irqsave(&port->lock, flags); | |
192 | h_lcr = *CSR_H_UBRLCR; | |
193 | if (break_state) | |
194 | h_lcr |= H_UBRLCR_BREAK; | |
195 | else | |
196 | h_lcr &= ~H_UBRLCR_BREAK; | |
197 | *CSR_H_UBRLCR = h_lcr; | |
198 | spin_unlock_irqrestore(&port->lock, flags); | |
199 | } | |
200 | ||
201 | static int serial21285_startup(struct uart_port *port) | |
202 | { | |
203 | int ret; | |
204 | ||
205 | tx_enabled(port) = 1; | |
206 | rx_enabled(port) = 1; | |
207 | ||
208 | ret = request_irq(IRQ_CONRX, serial21285_rx_chars, 0, | |
209 | serial21285_name, port); | |
210 | if (ret == 0) { | |
211 | ret = request_irq(IRQ_CONTX, serial21285_tx_chars, 0, | |
212 | serial21285_name, port); | |
213 | if (ret) | |
214 | free_irq(IRQ_CONRX, port); | |
215 | } | |
216 | ||
217 | return ret; | |
218 | } | |
219 | ||
220 | static void serial21285_shutdown(struct uart_port *port) | |
221 | { | |
222 | free_irq(IRQ_CONTX, port); | |
223 | free_irq(IRQ_CONRX, port); | |
224 | } | |
225 | ||
226 | static void | |
227 | serial21285_set_termios(struct uart_port *port, struct termios *termios, | |
228 | struct termios *old) | |
229 | { | |
230 | unsigned long flags; | |
231 | unsigned int baud, quot, h_lcr; | |
232 | ||
233 | /* | |
234 | * We don't support modem control lines. | |
235 | */ | |
236 | termios->c_cflag &= ~(HUPCL | CRTSCTS | CMSPAR); | |
237 | termios->c_cflag |= CLOCAL; | |
238 | ||
239 | /* | |
240 | * We don't support BREAK character recognition. | |
241 | */ | |
242 | termios->c_iflag &= ~(IGNBRK | BRKINT); | |
243 | ||
244 | /* | |
245 | * Ask the core to calculate the divisor for us. | |
246 | */ | |
247 | baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16); | |
248 | quot = uart_get_divisor(port, baud); | |
249 | ||
250 | switch (termios->c_cflag & CSIZE) { | |
251 | case CS5: | |
252 | h_lcr = 0x00; | |
253 | break; | |
254 | case CS6: | |
255 | h_lcr = 0x20; | |
256 | break; | |
257 | case CS7: | |
258 | h_lcr = 0x40; | |
259 | break; | |
260 | default: /* CS8 */ | |
261 | h_lcr = 0x60; | |
262 | break; | |
263 | } | |
264 | ||
265 | if (termios->c_cflag & CSTOPB) | |
266 | h_lcr |= H_UBRLCR_STOPB; | |
267 | if (termios->c_cflag & PARENB) { | |
268 | h_lcr |= H_UBRLCR_PARENB; | |
269 | if (!(termios->c_cflag & PARODD)) | |
270 | h_lcr |= H_UBRLCR_PAREVN; | |
271 | } | |
272 | ||
273 | if (port->fifosize) | |
274 | h_lcr |= H_UBRLCR_FIFO; | |
275 | ||
276 | spin_lock_irqsave(&port->lock, flags); | |
277 | ||
278 | /* | |
279 | * Update the per-port timeout. | |
280 | */ | |
281 | uart_update_timeout(port, termios->c_cflag, baud); | |
282 | ||
283 | /* | |
284 | * Which character status flags are we interested in? | |
285 | */ | |
286 | port->read_status_mask = RXSTAT_OVERRUN; | |
287 | if (termios->c_iflag & INPCK) | |
288 | port->read_status_mask |= RXSTAT_FRAME | RXSTAT_PARITY; | |
289 | ||
290 | /* | |
291 | * Which character status flags should we ignore? | |
292 | */ | |
293 | port->ignore_status_mask = 0; | |
294 | if (termios->c_iflag & IGNPAR) | |
295 | port->ignore_status_mask |= RXSTAT_FRAME | RXSTAT_PARITY; | |
296 | if (termios->c_iflag & IGNBRK && termios->c_iflag & IGNPAR) | |
297 | port->ignore_status_mask |= RXSTAT_OVERRUN; | |
298 | ||
299 | /* | |
300 | * Ignore all characters if CREAD is not set. | |
301 | */ | |
302 | if ((termios->c_cflag & CREAD) == 0) | |
303 | port->ignore_status_mask |= RXSTAT_DUMMY_READ; | |
304 | ||
305 | quot -= 1; | |
306 | ||
307 | *CSR_UARTCON = 0; | |
308 | *CSR_L_UBRLCR = quot & 0xff; | |
309 | *CSR_M_UBRLCR = (quot >> 8) & 0x0f; | |
310 | *CSR_H_UBRLCR = h_lcr; | |
311 | *CSR_UARTCON = 1; | |
312 | ||
313 | spin_unlock_irqrestore(&port->lock, flags); | |
314 | } | |
315 | ||
316 | static const char *serial21285_type(struct uart_port *port) | |
317 | { | |
318 | return port->type == PORT_21285 ? "DC21285" : NULL; | |
319 | } | |
320 | ||
321 | static void serial21285_release_port(struct uart_port *port) | |
322 | { | |
323 | release_mem_region(port->mapbase, 32); | |
324 | } | |
325 | ||
326 | static int serial21285_request_port(struct uart_port *port) | |
327 | { | |
328 | return request_mem_region(port->mapbase, 32, serial21285_name) | |
329 | != NULL ? 0 : -EBUSY; | |
330 | } | |
331 | ||
332 | static void serial21285_config_port(struct uart_port *port, int flags) | |
333 | { | |
334 | if (flags & UART_CONFIG_TYPE && serial21285_request_port(port) == 0) | |
335 | port->type = PORT_21285; | |
336 | } | |
337 | ||
338 | /* | |
339 | * verify the new serial_struct (for TIOCSSERIAL). | |
340 | */ | |
341 | static int serial21285_verify_port(struct uart_port *port, struct serial_struct *ser) | |
342 | { | |
343 | int ret = 0; | |
344 | if (ser->type != PORT_UNKNOWN && ser->type != PORT_21285) | |
345 | ret = -EINVAL; | |
346 | if (ser->irq != NO_IRQ) | |
347 | ret = -EINVAL; | |
348 | if (ser->baud_base != port->uartclk / 16) | |
349 | ret = -EINVAL; | |
350 | return ret; | |
351 | } | |
352 | ||
353 | static struct uart_ops serial21285_ops = { | |
354 | .tx_empty = serial21285_tx_empty, | |
355 | .get_mctrl = serial21285_get_mctrl, | |
356 | .set_mctrl = serial21285_set_mctrl, | |
357 | .stop_tx = serial21285_stop_tx, | |
358 | .start_tx = serial21285_start_tx, | |
359 | .stop_rx = serial21285_stop_rx, | |
360 | .enable_ms = serial21285_enable_ms, | |
361 | .break_ctl = serial21285_break_ctl, | |
362 | .startup = serial21285_startup, | |
363 | .shutdown = serial21285_shutdown, | |
364 | .set_termios = serial21285_set_termios, | |
365 | .type = serial21285_type, | |
366 | .release_port = serial21285_release_port, | |
367 | .request_port = serial21285_request_port, | |
368 | .config_port = serial21285_config_port, | |
369 | .verify_port = serial21285_verify_port, | |
370 | }; | |
371 | ||
372 | static struct uart_port serial21285_port = { | |
373 | .mapbase = 0x42000160, | |
374 | .iotype = SERIAL_IO_MEM, | |
375 | .irq = NO_IRQ, | |
376 | .fifosize = 16, | |
377 | .ops = &serial21285_ops, | |
378 | .flags = ASYNC_BOOT_AUTOCONF, | |
379 | }; | |
380 | ||
381 | static void serial21285_setup_ports(void) | |
382 | { | |
383 | serial21285_port.uartclk = mem_fclk_21285 / 4; | |
384 | } | |
385 | ||
386 | #ifdef CONFIG_SERIAL_21285_CONSOLE | |
387 | ||
388 | static void | |
389 | serial21285_console_write(struct console *co, const char *s, | |
390 | unsigned int count) | |
391 | { | |
392 | int i; | |
393 | ||
394 | for (i = 0; i < count; i++) { | |
395 | while (*CSR_UARTFLG & 0x20) | |
396 | barrier(); | |
397 | *CSR_UARTDR = s[i]; | |
398 | if (s[i] == '\n') { | |
399 | while (*CSR_UARTFLG & 0x20) | |
400 | barrier(); | |
401 | *CSR_UARTDR = '\r'; | |
402 | } | |
403 | } | |
404 | } | |
405 | ||
406 | static void __init | |
407 | serial21285_get_options(struct uart_port *port, int *baud, | |
408 | int *parity, int *bits) | |
409 | { | |
410 | if (*CSR_UARTCON == 1) { | |
411 | unsigned int tmp; | |
412 | ||
413 | tmp = *CSR_H_UBRLCR; | |
414 | switch (tmp & 0x60) { | |
415 | case 0x00: | |
416 | *bits = 5; | |
417 | break; | |
418 | case 0x20: | |
419 | *bits = 6; | |
420 | break; | |
421 | case 0x40: | |
422 | *bits = 7; | |
423 | break; | |
424 | default: | |
425 | case 0x60: | |
426 | *bits = 8; | |
427 | break; | |
428 | } | |
429 | ||
430 | if (tmp & H_UBRLCR_PARENB) { | |
431 | *parity = 'o'; | |
432 | if (tmp & H_UBRLCR_PAREVN) | |
433 | *parity = 'e'; | |
434 | } | |
435 | ||
436 | tmp = *CSR_L_UBRLCR | (*CSR_M_UBRLCR << 8); | |
437 | ||
438 | *baud = port->uartclk / (16 * (tmp + 1)); | |
439 | } | |
440 | } | |
441 | ||
442 | static int __init serial21285_console_setup(struct console *co, char *options) | |
443 | { | |
444 | struct uart_port *port = &serial21285_port; | |
445 | int baud = 9600; | |
446 | int bits = 8; | |
447 | int parity = 'n'; | |
448 | int flow = 'n'; | |
449 | ||
450 | if (machine_is_personal_server()) | |
451 | baud = 57600; | |
452 | ||
453 | /* | |
454 | * Check whether an invalid uart number has been specified, and | |
455 | * if so, search for the first available port that does have | |
456 | * console support. | |
457 | */ | |
458 | if (options) | |
459 | uart_parse_options(options, &baud, &parity, &bits, &flow); | |
460 | else | |
461 | serial21285_get_options(port, &baud, &parity, &bits); | |
462 | ||
463 | return uart_set_options(port, co, baud, parity, bits, flow); | |
464 | } | |
465 | ||
466 | extern struct uart_driver serial21285_reg; | |
467 | ||
468 | static struct console serial21285_console = | |
469 | { | |
470 | .name = SERIAL_21285_NAME, | |
471 | .write = serial21285_console_write, | |
472 | .device = uart_console_device, | |
473 | .setup = serial21285_console_setup, | |
474 | .flags = CON_PRINTBUFFER, | |
475 | .index = -1, | |
476 | .data = &serial21285_reg, | |
477 | }; | |
478 | ||
479 | static int __init rs285_console_init(void) | |
480 | { | |
481 | serial21285_setup_ports(); | |
482 | register_console(&serial21285_console); | |
483 | return 0; | |
484 | } | |
485 | console_initcall(rs285_console_init); | |
486 | ||
487 | #define SERIAL_21285_CONSOLE &serial21285_console | |
488 | #else | |
489 | #define SERIAL_21285_CONSOLE NULL | |
490 | #endif | |
491 | ||
492 | static struct uart_driver serial21285_reg = { | |
493 | .owner = THIS_MODULE, | |
494 | .driver_name = "ttyFB", | |
495 | .dev_name = "ttyFB", | |
496 | .devfs_name = "ttyFB", | |
497 | .major = SERIAL_21285_MAJOR, | |
498 | .minor = SERIAL_21285_MINOR, | |
499 | .nr = 1, | |
500 | .cons = SERIAL_21285_CONSOLE, | |
501 | }; | |
502 | ||
503 | static int __init serial21285_init(void) | |
504 | { | |
505 | int ret; | |
506 | ||
507 | printk(KERN_INFO "Serial: 21285 driver $Revision: 1.37 $\n"); | |
508 | ||
509 | serial21285_setup_ports(); | |
510 | ||
511 | ret = uart_register_driver(&serial21285_reg); | |
512 | if (ret == 0) | |
513 | uart_add_one_port(&serial21285_reg, &serial21285_port); | |
514 | ||
515 | return ret; | |
516 | } | |
517 | ||
518 | static void __exit serial21285_exit(void) | |
519 | { | |
520 | uart_remove_one_port(&serial21285_reg, &serial21285_port); | |
521 | uart_unregister_driver(&serial21285_reg); | |
522 | } | |
523 | ||
524 | module_init(serial21285_init); | |
525 | module_exit(serial21285_exit); | |
526 | ||
527 | MODULE_LICENSE("GPL"); | |
528 | MODULE_DESCRIPTION("Intel Footbridge (21285) serial driver $Revision: 1.37 $"); | |
529 | MODULE_ALIAS_CHARDEV(SERIAL_21285_MAJOR, SERIAL_21285_MINOR); |