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Commit | Line | Data |
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1da177e4 | 1 | /* |
f30c2269 | 2 | * linux/drivers/serial/21285.c |
1da177e4 LT |
3 | * |
4 | * Driver for the serial port on the 21285 StrongArm-110 core logic chip. | |
5 | * | |
6 | * Based on drivers/char/serial.c | |
1da177e4 | 7 | */ |
1da177e4 LT |
8 | #include <linux/module.h> |
9 | #include <linux/tty.h> | |
10 | #include <linux/ioport.h> | |
11 | #include <linux/init.h> | |
12 | #include <linux/console.h> | |
13 | #include <linux/device.h> | |
14 | #include <linux/tty_flip.h> | |
15 | #include <linux/serial_core.h> | |
16 | #include <linux/serial.h> | |
99730225 | 17 | #include <linux/io.h> |
1da177e4 | 18 | |
1da177e4 LT |
19 | #include <asm/irq.h> |
20 | #include <asm/mach-types.h> | |
21 | #include <asm/hardware/dec21285.h> | |
a09e64fb | 22 | #include <mach/hardware.h> |
1da177e4 LT |
23 | |
24 | #define BAUD_BASE (mem_fclk_21285/64) | |
25 | ||
26 | #define SERIAL_21285_NAME "ttyFB" | |
27 | #define SERIAL_21285_MAJOR 204 | |
28 | #define SERIAL_21285_MINOR 4 | |
29 | ||
30 | #define RXSTAT_DUMMY_READ 0x80000000 | |
31 | #define RXSTAT_FRAME (1 << 0) | |
32 | #define RXSTAT_PARITY (1 << 1) | |
33 | #define RXSTAT_OVERRUN (1 << 2) | |
34 | #define RXSTAT_ANYERR (RXSTAT_FRAME|RXSTAT_PARITY|RXSTAT_OVERRUN) | |
35 | ||
36 | #define H_UBRLCR_BREAK (1 << 0) | |
37 | #define H_UBRLCR_PARENB (1 << 1) | |
38 | #define H_UBRLCR_PAREVN (1 << 2) | |
39 | #define H_UBRLCR_STOPB (1 << 3) | |
40 | #define H_UBRLCR_FIFO (1 << 4) | |
41 | ||
42 | static const char serial21285_name[] = "Footbridge UART"; | |
43 | ||
44 | #define tx_enabled(port) ((port)->unused[0]) | |
45 | #define rx_enabled(port) ((port)->unused[1]) | |
46 | ||
47 | /* | |
48 | * The documented expression for selecting the divisor is: | |
49 | * BAUD_BASE / baud - 1 | |
50 | * However, typically BAUD_BASE is not divisible by baud, so | |
51 | * we want to select the divisor that gives us the minimum | |
52 | * error. Therefore, we want: | |
53 | * int(BAUD_BASE / baud - 0.5) -> | |
54 | * int(BAUD_BASE / baud - (baud >> 1) / baud) -> | |
55 | * int((BAUD_BASE - (baud >> 1)) / baud) | |
56 | */ | |
57 | ||
b129a8cc | 58 | static void serial21285_stop_tx(struct uart_port *port) |
1da177e4 LT |
59 | { |
60 | if (tx_enabled(port)) { | |
61 | disable_irq(IRQ_CONTX); | |
62 | tx_enabled(port) = 0; | |
63 | } | |
64 | } | |
65 | ||
b129a8cc | 66 | static void serial21285_start_tx(struct uart_port *port) |
1da177e4 LT |
67 | { |
68 | if (!tx_enabled(port)) { | |
69 | enable_irq(IRQ_CONTX); | |
70 | tx_enabled(port) = 1; | |
71 | } | |
72 | } | |
73 | ||
74 | static void serial21285_stop_rx(struct uart_port *port) | |
75 | { | |
76 | if (rx_enabled(port)) { | |
77 | disable_irq(IRQ_CONRX); | |
78 | rx_enabled(port) = 0; | |
79 | } | |
80 | } | |
81 | ||
82 | static void serial21285_enable_ms(struct uart_port *port) | |
83 | { | |
84 | } | |
85 | ||
7d12e780 | 86 | static irqreturn_t serial21285_rx_chars(int irq, void *dev_id) |
1da177e4 LT |
87 | { |
88 | struct uart_port *port = dev_id; | |
ebd2c8f6 | 89 | struct tty_struct *tty = port->state->port.tty; |
1da177e4 LT |
90 | unsigned int status, ch, flag, rxs, max_count = 256; |
91 | ||
92 | status = *CSR_UARTFLG; | |
93 | while (!(status & 0x10) && max_count--) { | |
1da177e4 LT |
94 | ch = *CSR_UARTDR; |
95 | flag = TTY_NORMAL; | |
96 | port->icount.rx++; | |
97 | ||
98 | rxs = *CSR_RXSTAT | RXSTAT_DUMMY_READ; | |
45849282 | 99 | if (unlikely(rxs & RXSTAT_ANYERR)) { |
1da177e4 LT |
100 | if (rxs & RXSTAT_PARITY) |
101 | port->icount.parity++; | |
102 | else if (rxs & RXSTAT_FRAME) | |
103 | port->icount.frame++; | |
104 | if (rxs & RXSTAT_OVERRUN) | |
105 | port->icount.overrun++; | |
106 | ||
107 | rxs &= port->read_status_mask; | |
108 | ||
109 | if (rxs & RXSTAT_PARITY) | |
110 | flag = TTY_PARITY; | |
111 | else if (rxs & RXSTAT_FRAME) | |
112 | flag = TTY_FRAME; | |
113 | } | |
114 | ||
05ab3014 RK |
115 | uart_insert_char(port, rxs, RXSTAT_OVERRUN, ch, flag); |
116 | ||
1da177e4 LT |
117 | status = *CSR_UARTFLG; |
118 | } | |
119 | tty_flip_buffer_push(tty); | |
120 | ||
121 | return IRQ_HANDLED; | |
122 | } | |
123 | ||
7d12e780 | 124 | static irqreturn_t serial21285_tx_chars(int irq, void *dev_id) |
1da177e4 LT |
125 | { |
126 | struct uart_port *port = dev_id; | |
ebd2c8f6 | 127 | struct circ_buf *xmit = &port->state->xmit; |
1da177e4 LT |
128 | int count = 256; |
129 | ||
130 | if (port->x_char) { | |
131 | *CSR_UARTDR = port->x_char; | |
132 | port->icount.tx++; | |
133 | port->x_char = 0; | |
134 | goto out; | |
135 | } | |
136 | if (uart_circ_empty(xmit) || uart_tx_stopped(port)) { | |
b129a8cc | 137 | serial21285_stop_tx(port); |
1da177e4 LT |
138 | goto out; |
139 | } | |
140 | ||
141 | do { | |
142 | *CSR_UARTDR = xmit->buf[xmit->tail]; | |
143 | xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); | |
144 | port->icount.tx++; | |
145 | if (uart_circ_empty(xmit)) | |
146 | break; | |
147 | } while (--count > 0 && !(*CSR_UARTFLG & 0x20)); | |
148 | ||
149 | if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) | |
150 | uart_write_wakeup(port); | |
151 | ||
152 | if (uart_circ_empty(xmit)) | |
b129a8cc | 153 | serial21285_stop_tx(port); |
1da177e4 LT |
154 | |
155 | out: | |
156 | return IRQ_HANDLED; | |
157 | } | |
158 | ||
159 | static unsigned int serial21285_tx_empty(struct uart_port *port) | |
160 | { | |
161 | return (*CSR_UARTFLG & 8) ? 0 : TIOCSER_TEMT; | |
162 | } | |
163 | ||
164 | /* no modem control lines */ | |
165 | static unsigned int serial21285_get_mctrl(struct uart_port *port) | |
166 | { | |
167 | return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS; | |
168 | } | |
169 | ||
170 | static void serial21285_set_mctrl(struct uart_port *port, unsigned int mctrl) | |
171 | { | |
172 | } | |
173 | ||
174 | static void serial21285_break_ctl(struct uart_port *port, int break_state) | |
175 | { | |
176 | unsigned long flags; | |
177 | unsigned int h_lcr; | |
178 | ||
179 | spin_lock_irqsave(&port->lock, flags); | |
180 | h_lcr = *CSR_H_UBRLCR; | |
181 | if (break_state) | |
182 | h_lcr |= H_UBRLCR_BREAK; | |
183 | else | |
184 | h_lcr &= ~H_UBRLCR_BREAK; | |
185 | *CSR_H_UBRLCR = h_lcr; | |
186 | spin_unlock_irqrestore(&port->lock, flags); | |
187 | } | |
188 | ||
189 | static int serial21285_startup(struct uart_port *port) | |
190 | { | |
191 | int ret; | |
192 | ||
193 | tx_enabled(port) = 1; | |
194 | rx_enabled(port) = 1; | |
195 | ||
196 | ret = request_irq(IRQ_CONRX, serial21285_rx_chars, 0, | |
197 | serial21285_name, port); | |
198 | if (ret == 0) { | |
199 | ret = request_irq(IRQ_CONTX, serial21285_tx_chars, 0, | |
200 | serial21285_name, port); | |
201 | if (ret) | |
202 | free_irq(IRQ_CONRX, port); | |
203 | } | |
204 | ||
205 | return ret; | |
206 | } | |
207 | ||
208 | static void serial21285_shutdown(struct uart_port *port) | |
209 | { | |
210 | free_irq(IRQ_CONTX, port); | |
211 | free_irq(IRQ_CONRX, port); | |
212 | } | |
213 | ||
214 | static void | |
606d099c AC |
215 | serial21285_set_termios(struct uart_port *port, struct ktermios *termios, |
216 | struct ktermios *old) | |
1da177e4 LT |
217 | { |
218 | unsigned long flags; | |
219 | unsigned int baud, quot, h_lcr; | |
220 | ||
221 | /* | |
222 | * We don't support modem control lines. | |
223 | */ | |
224 | termios->c_cflag &= ~(HUPCL | CRTSCTS | CMSPAR); | |
225 | termios->c_cflag |= CLOCAL; | |
226 | ||
227 | /* | |
228 | * We don't support BREAK character recognition. | |
229 | */ | |
230 | termios->c_iflag &= ~(IGNBRK | BRKINT); | |
231 | ||
232 | /* | |
233 | * Ask the core to calculate the divisor for us. | |
234 | */ | |
235 | baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16); | |
236 | quot = uart_get_divisor(port, baud); | |
237 | ||
ebd2c8f6 AC |
238 | if (port->state && port->state->port.tty) { |
239 | struct tty_struct *tty = port->state->port.tty; | |
2f65baff RK |
240 | unsigned int b = port->uartclk / (16 * quot); |
241 | tty_encode_baud_rate(tty, b, b); | |
242 | } | |
243 | ||
1da177e4 LT |
244 | switch (termios->c_cflag & CSIZE) { |
245 | case CS5: | |
246 | h_lcr = 0x00; | |
247 | break; | |
248 | case CS6: | |
249 | h_lcr = 0x20; | |
250 | break; | |
251 | case CS7: | |
252 | h_lcr = 0x40; | |
253 | break; | |
254 | default: /* CS8 */ | |
255 | h_lcr = 0x60; | |
256 | break; | |
257 | } | |
258 | ||
259 | if (termios->c_cflag & CSTOPB) | |
260 | h_lcr |= H_UBRLCR_STOPB; | |
261 | if (termios->c_cflag & PARENB) { | |
262 | h_lcr |= H_UBRLCR_PARENB; | |
263 | if (!(termios->c_cflag & PARODD)) | |
264 | h_lcr |= H_UBRLCR_PAREVN; | |
265 | } | |
266 | ||
267 | if (port->fifosize) | |
268 | h_lcr |= H_UBRLCR_FIFO; | |
269 | ||
270 | spin_lock_irqsave(&port->lock, flags); | |
271 | ||
272 | /* | |
273 | * Update the per-port timeout. | |
274 | */ | |
275 | uart_update_timeout(port, termios->c_cflag, baud); | |
276 | ||
277 | /* | |
278 | * Which character status flags are we interested in? | |
279 | */ | |
280 | port->read_status_mask = RXSTAT_OVERRUN; | |
281 | if (termios->c_iflag & INPCK) | |
282 | port->read_status_mask |= RXSTAT_FRAME | RXSTAT_PARITY; | |
283 | ||
284 | /* | |
285 | * Which character status flags should we ignore? | |
286 | */ | |
287 | port->ignore_status_mask = 0; | |
288 | if (termios->c_iflag & IGNPAR) | |
289 | port->ignore_status_mask |= RXSTAT_FRAME | RXSTAT_PARITY; | |
290 | if (termios->c_iflag & IGNBRK && termios->c_iflag & IGNPAR) | |
291 | port->ignore_status_mask |= RXSTAT_OVERRUN; | |
292 | ||
293 | /* | |
294 | * Ignore all characters if CREAD is not set. | |
295 | */ | |
296 | if ((termios->c_cflag & CREAD) == 0) | |
297 | port->ignore_status_mask |= RXSTAT_DUMMY_READ; | |
298 | ||
299 | quot -= 1; | |
300 | ||
301 | *CSR_UARTCON = 0; | |
302 | *CSR_L_UBRLCR = quot & 0xff; | |
303 | *CSR_M_UBRLCR = (quot >> 8) & 0x0f; | |
304 | *CSR_H_UBRLCR = h_lcr; | |
305 | *CSR_UARTCON = 1; | |
306 | ||
307 | spin_unlock_irqrestore(&port->lock, flags); | |
308 | } | |
309 | ||
310 | static const char *serial21285_type(struct uart_port *port) | |
311 | { | |
312 | return port->type == PORT_21285 ? "DC21285" : NULL; | |
313 | } | |
314 | ||
315 | static void serial21285_release_port(struct uart_port *port) | |
316 | { | |
317 | release_mem_region(port->mapbase, 32); | |
318 | } | |
319 | ||
320 | static int serial21285_request_port(struct uart_port *port) | |
321 | { | |
322 | return request_mem_region(port->mapbase, 32, serial21285_name) | |
323 | != NULL ? 0 : -EBUSY; | |
324 | } | |
325 | ||
326 | static void serial21285_config_port(struct uart_port *port, int flags) | |
327 | { | |
328 | if (flags & UART_CONFIG_TYPE && serial21285_request_port(port) == 0) | |
329 | port->type = PORT_21285; | |
330 | } | |
331 | ||
332 | /* | |
333 | * verify the new serial_struct (for TIOCSSERIAL). | |
334 | */ | |
335 | static int serial21285_verify_port(struct uart_port *port, struct serial_struct *ser) | |
336 | { | |
337 | int ret = 0; | |
338 | if (ser->type != PORT_UNKNOWN && ser->type != PORT_21285) | |
339 | ret = -EINVAL; | |
340 | if (ser->irq != NO_IRQ) | |
341 | ret = -EINVAL; | |
342 | if (ser->baud_base != port->uartclk / 16) | |
343 | ret = -EINVAL; | |
344 | return ret; | |
345 | } | |
346 | ||
347 | static struct uart_ops serial21285_ops = { | |
348 | .tx_empty = serial21285_tx_empty, | |
349 | .get_mctrl = serial21285_get_mctrl, | |
350 | .set_mctrl = serial21285_set_mctrl, | |
351 | .stop_tx = serial21285_stop_tx, | |
352 | .start_tx = serial21285_start_tx, | |
353 | .stop_rx = serial21285_stop_rx, | |
354 | .enable_ms = serial21285_enable_ms, | |
355 | .break_ctl = serial21285_break_ctl, | |
356 | .startup = serial21285_startup, | |
357 | .shutdown = serial21285_shutdown, | |
358 | .set_termios = serial21285_set_termios, | |
359 | .type = serial21285_type, | |
360 | .release_port = serial21285_release_port, | |
361 | .request_port = serial21285_request_port, | |
362 | .config_port = serial21285_config_port, | |
363 | .verify_port = serial21285_verify_port, | |
364 | }; | |
365 | ||
366 | static struct uart_port serial21285_port = { | |
367 | .mapbase = 0x42000160, | |
9b4a1617 | 368 | .iotype = UPIO_MEM, |
1da177e4 LT |
369 | .irq = NO_IRQ, |
370 | .fifosize = 16, | |
371 | .ops = &serial21285_ops, | |
ce8337cb | 372 | .flags = UPF_BOOT_AUTOCONF, |
1da177e4 LT |
373 | }; |
374 | ||
375 | static void serial21285_setup_ports(void) | |
376 | { | |
377 | serial21285_port.uartclk = mem_fclk_21285 / 4; | |
378 | } | |
379 | ||
380 | #ifdef CONFIG_SERIAL_21285_CONSOLE | |
d358788f RK |
381 | static void serial21285_console_putchar(struct uart_port *port, int ch) |
382 | { | |
383 | while (*CSR_UARTFLG & 0x20) | |
384 | barrier(); | |
385 | *CSR_UARTDR = ch; | |
386 | } | |
1da177e4 LT |
387 | |
388 | static void | |
389 | serial21285_console_write(struct console *co, const char *s, | |
390 | unsigned int count) | |
391 | { | |
d358788f | 392 | uart_console_write(&serial21285_port, s, count, serial21285_console_putchar); |
1da177e4 LT |
393 | } |
394 | ||
395 | static void __init | |
396 | serial21285_get_options(struct uart_port *port, int *baud, | |
397 | int *parity, int *bits) | |
398 | { | |
399 | if (*CSR_UARTCON == 1) { | |
400 | unsigned int tmp; | |
401 | ||
402 | tmp = *CSR_H_UBRLCR; | |
403 | switch (tmp & 0x60) { | |
404 | case 0x00: | |
405 | *bits = 5; | |
406 | break; | |
407 | case 0x20: | |
408 | *bits = 6; | |
409 | break; | |
410 | case 0x40: | |
411 | *bits = 7; | |
412 | break; | |
413 | default: | |
414 | case 0x60: | |
415 | *bits = 8; | |
416 | break; | |
417 | } | |
418 | ||
419 | if (tmp & H_UBRLCR_PARENB) { | |
420 | *parity = 'o'; | |
421 | if (tmp & H_UBRLCR_PAREVN) | |
422 | *parity = 'e'; | |
423 | } | |
424 | ||
425 | tmp = *CSR_L_UBRLCR | (*CSR_M_UBRLCR << 8); | |
426 | ||
427 | *baud = port->uartclk / (16 * (tmp + 1)); | |
428 | } | |
429 | } | |
430 | ||
431 | static int __init serial21285_console_setup(struct console *co, char *options) | |
432 | { | |
433 | struct uart_port *port = &serial21285_port; | |
434 | int baud = 9600; | |
435 | int bits = 8; | |
436 | int parity = 'n'; | |
437 | int flow = 'n'; | |
438 | ||
439 | if (machine_is_personal_server()) | |
440 | baud = 57600; | |
441 | ||
442 | /* | |
443 | * Check whether an invalid uart number has been specified, and | |
444 | * if so, search for the first available port that does have | |
445 | * console support. | |
446 | */ | |
447 | if (options) | |
448 | uart_parse_options(options, &baud, &parity, &bits, &flow); | |
449 | else | |
450 | serial21285_get_options(port, &baud, &parity, &bits); | |
451 | ||
452 | return uart_set_options(port, co, baud, parity, bits, flow); | |
453 | } | |
454 | ||
2d93486c | 455 | static struct uart_driver serial21285_reg; |
1da177e4 LT |
456 | |
457 | static struct console serial21285_console = | |
458 | { | |
459 | .name = SERIAL_21285_NAME, | |
460 | .write = serial21285_console_write, | |
461 | .device = uart_console_device, | |
462 | .setup = serial21285_console_setup, | |
463 | .flags = CON_PRINTBUFFER, | |
464 | .index = -1, | |
465 | .data = &serial21285_reg, | |
466 | }; | |
467 | ||
468 | static int __init rs285_console_init(void) | |
469 | { | |
470 | serial21285_setup_ports(); | |
471 | register_console(&serial21285_console); | |
472 | return 0; | |
473 | } | |
474 | console_initcall(rs285_console_init); | |
475 | ||
476 | #define SERIAL_21285_CONSOLE &serial21285_console | |
477 | #else | |
478 | #define SERIAL_21285_CONSOLE NULL | |
479 | #endif | |
480 | ||
481 | static struct uart_driver serial21285_reg = { | |
482 | .owner = THIS_MODULE, | |
483 | .driver_name = "ttyFB", | |
484 | .dev_name = "ttyFB", | |
1da177e4 LT |
485 | .major = SERIAL_21285_MAJOR, |
486 | .minor = SERIAL_21285_MINOR, | |
487 | .nr = 1, | |
488 | .cons = SERIAL_21285_CONSOLE, | |
489 | }; | |
490 | ||
491 | static int __init serial21285_init(void) | |
492 | { | |
493 | int ret; | |
494 | ||
d87a6d95 | 495 | printk(KERN_INFO "Serial: 21285 driver\n"); |
1da177e4 LT |
496 | |
497 | serial21285_setup_ports(); | |
498 | ||
499 | ret = uart_register_driver(&serial21285_reg); | |
500 | if (ret == 0) | |
501 | uart_add_one_port(&serial21285_reg, &serial21285_port); | |
502 | ||
503 | return ret; | |
504 | } | |
505 | ||
506 | static void __exit serial21285_exit(void) | |
507 | { | |
508 | uart_remove_one_port(&serial21285_reg, &serial21285_port); | |
509 | uart_unregister_driver(&serial21285_reg); | |
510 | } | |
511 | ||
512 | module_init(serial21285_init); | |
513 | module_exit(serial21285_exit); | |
514 | ||
515 | MODULE_LICENSE("GPL"); | |
d87a6d95 | 516 | MODULE_DESCRIPTION("Intel Footbridge (21285) serial driver"); |
1da177e4 | 517 | MODULE_ALIAS_CHARDEV(SERIAL_21285_MAJOR, SERIAL_21285_MINOR); |