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12#include <linux/kernel.h>
13#include <linux/init.h>
14#include <linux/interrupt.h>
15#include <linux/module.h>
16#include <linux/console.h>
17#include <linux/of.h>
18#include <linux/tty.h>
19#include <linux/tty_flip.h>
20#include <linux/serial.h>
21#include <linux/serial_core.h>
22#include <linux/platform_device.h>
23#include <linux/io.h>
24#include <linux/altera_jtaguart.h>
25
26#define DRV_NAME "altera_jtaguart"
27
28
29
30
31
32
33#define ALTERA_JTAGUART_SIZE 8
34
35#define ALTERA_JTAGUART_DATA_REG 0
36
37#define ALTERA_JTAGUART_DATA_DATA_MSK 0x000000FF
38#define ALTERA_JTAGUART_DATA_RVALID_MSK 0x00008000
39#define ALTERA_JTAGUART_DATA_RAVAIL_MSK 0xFFFF0000
40#define ALTERA_JTAGUART_DATA_RAVAIL_OFF 16
41
42#define ALTERA_JTAGUART_CONTROL_REG 4
43
44#define ALTERA_JTAGUART_CONTROL_RE_MSK 0x00000001
45#define ALTERA_JTAGUART_CONTROL_WE_MSK 0x00000002
46#define ALTERA_JTAGUART_CONTROL_RI_MSK 0x00000100
47#define ALTERA_JTAGUART_CONTROL_RI_OFF 8
48#define ALTERA_JTAGUART_CONTROL_WI_MSK 0x00000200
49#define ALTERA_JTAGUART_CONTROL_AC_MSK 0x00000400
50#define ALTERA_JTAGUART_CONTROL_WSPACE_MSK 0xFFFF0000
51#define ALTERA_JTAGUART_CONTROL_WSPACE_OFF 16
52
53
54
55
56struct altera_jtaguart {
57 struct uart_port port;
58 unsigned int sigs;
59 unsigned long imr;
60};
61
62static unsigned int altera_jtaguart_tx_empty(struct uart_port *port)
63{
64 return (readl(port->membase + ALTERA_JTAGUART_CONTROL_REG) &
65 ALTERA_JTAGUART_CONTROL_WSPACE_MSK) ? TIOCSER_TEMT : 0;
66}
67
68static unsigned int altera_jtaguart_get_mctrl(struct uart_port *port)
69{
70 return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
71}
72
73static void altera_jtaguart_set_mctrl(struct uart_port *port, unsigned int sigs)
74{
75}
76
77static void altera_jtaguart_start_tx(struct uart_port *port)
78{
79 struct altera_jtaguart *pp =
80 container_of(port, struct altera_jtaguart, port);
81
82 pp->imr |= ALTERA_JTAGUART_CONTROL_WE_MSK;
83 writel(pp->imr, port->membase + ALTERA_JTAGUART_CONTROL_REG);
84}
85
86static void altera_jtaguart_stop_tx(struct uart_port *port)
87{
88 struct altera_jtaguart *pp =
89 container_of(port, struct altera_jtaguart, port);
90
91 pp->imr &= ~ALTERA_JTAGUART_CONTROL_WE_MSK;
92 writel(pp->imr, port->membase + ALTERA_JTAGUART_CONTROL_REG);
93}
94
95static void altera_jtaguart_stop_rx(struct uart_port *port)
96{
97 struct altera_jtaguart *pp =
98 container_of(port, struct altera_jtaguart, port);
99
100 pp->imr &= ~ALTERA_JTAGUART_CONTROL_RE_MSK;
101 writel(pp->imr, port->membase + ALTERA_JTAGUART_CONTROL_REG);
102}
103
104static void altera_jtaguart_break_ctl(struct uart_port *port, int break_state)
105{
106}
107
108static void altera_jtaguart_set_termios(struct uart_port *port,
109 struct ktermios *termios,
110 struct ktermios *old)
111{
112
113 if (old)
114 tty_termios_copy_hw(termios, old);
115}
116
117static void altera_jtaguart_rx_chars(struct altera_jtaguart *pp)
118{
119 struct uart_port *port = &pp->port;
120 unsigned char ch, flag;
121 unsigned long status;
122
123 while ((status = readl(port->membase + ALTERA_JTAGUART_DATA_REG)) &
124 ALTERA_JTAGUART_DATA_RVALID_MSK) {
125 ch = status & ALTERA_JTAGUART_DATA_DATA_MSK;
126 flag = TTY_NORMAL;
127 port->icount.rx++;
128
129 if (uart_handle_sysrq_char(port, ch))
130 continue;
131 uart_insert_char(port, 0, 0, ch, flag);
132 }
133
134 spin_unlock(&port->lock);
135 tty_flip_buffer_push(&port->state->port);
136 spin_lock(&port->lock);
137}
138
139static void altera_jtaguart_tx_chars(struct altera_jtaguart *pp)
140{
141 struct uart_port *port = &pp->port;
142 struct circ_buf *xmit = &port->state->xmit;
143 unsigned int pending, count;
144
145 if (port->x_char) {
146
147 writel(port->x_char, port->membase + ALTERA_JTAGUART_DATA_REG);
148 port->x_char = 0;
149 port->icount.tx++;
150 return;
151 }
152
153 pending = uart_circ_chars_pending(xmit);
154 if (pending > 0) {
155 count = (readl(port->membase + ALTERA_JTAGUART_CONTROL_REG) &
156 ALTERA_JTAGUART_CONTROL_WSPACE_MSK) >>
157 ALTERA_JTAGUART_CONTROL_WSPACE_OFF;
158 if (count > pending)
159 count = pending;
160 if (count > 0) {
161 pending -= count;
162 while (count--) {
163 writel(xmit->buf[xmit->tail],
164 port->membase + ALTERA_JTAGUART_DATA_REG);
165 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
166 port->icount.tx++;
167 }
168 if (pending < WAKEUP_CHARS)
169 uart_write_wakeup(port);
170 }
171 }
172
173 if (pending == 0) {
174 pp->imr &= ~ALTERA_JTAGUART_CONTROL_WE_MSK;
175 writel(pp->imr, port->membase + ALTERA_JTAGUART_CONTROL_REG);
176 }
177}
178
179static irqreturn_t altera_jtaguart_interrupt(int irq, void *data)
180{
181 struct uart_port *port = data;
182 struct altera_jtaguart *pp =
183 container_of(port, struct altera_jtaguart, port);
184 unsigned int isr;
185
186 isr = (readl(port->membase + ALTERA_JTAGUART_CONTROL_REG) >>
187 ALTERA_JTAGUART_CONTROL_RI_OFF) & pp->imr;
188
189 spin_lock(&port->lock);
190
191 if (isr & ALTERA_JTAGUART_CONTROL_RE_MSK)
192 altera_jtaguart_rx_chars(pp);
193 if (isr & ALTERA_JTAGUART_CONTROL_WE_MSK)
194 altera_jtaguart_tx_chars(pp);
195
196 spin_unlock(&port->lock);
197
198 return IRQ_RETVAL(isr);
199}
200
201static void altera_jtaguart_config_port(struct uart_port *port, int flags)
202{
203 port->type = PORT_ALTERA_JTAGUART;
204
205
206 writel(0, port->membase + ALTERA_JTAGUART_CONTROL_REG);
207}
208
209static int altera_jtaguart_startup(struct uart_port *port)
210{
211 struct altera_jtaguart *pp =
212 container_of(port, struct altera_jtaguart, port);
213 unsigned long flags;
214 int ret;
215
216 ret = request_irq(port->irq, altera_jtaguart_interrupt, 0,
217 DRV_NAME, port);
218 if (ret) {
219 pr_err(DRV_NAME ": unable to attach Altera JTAG UART %d "
220 "interrupt vector=%d\n", port->line, port->irq);
221 return ret;
222 }
223
224 spin_lock_irqsave(&port->lock, flags);
225
226
227 pp->imr = ALTERA_JTAGUART_CONTROL_RE_MSK;
228 writel(pp->imr, port->membase + ALTERA_JTAGUART_CONTROL_REG);
229
230 spin_unlock_irqrestore(&port->lock, flags);
231
232 return 0;
233}
234
235static void altera_jtaguart_shutdown(struct uart_port *port)
236{
237 struct altera_jtaguart *pp =
238 container_of(port, struct altera_jtaguart, port);
239 unsigned long flags;
240
241 spin_lock_irqsave(&port->lock, flags);
242
243
244 pp->imr = 0;
245 writel(pp->imr, port->membase + ALTERA_JTAGUART_CONTROL_REG);
246
247 spin_unlock_irqrestore(&port->lock, flags);
248
249 free_irq(port->irq, port);
250}
251
252static const char *altera_jtaguart_type(struct uart_port *port)
253{
254 return (port->type == PORT_ALTERA_JTAGUART) ? "Altera JTAG UART" : NULL;
255}
256
257static int altera_jtaguart_request_port(struct uart_port *port)
258{
259
260 return 0;
261}
262
263static void altera_jtaguart_release_port(struct uart_port *port)
264{
265
266}
267
268static int altera_jtaguart_verify_port(struct uart_port *port,
269 struct serial_struct *ser)
270{
271 if (ser->type != PORT_UNKNOWN && ser->type != PORT_ALTERA_JTAGUART)
272 return -EINVAL;
273 return 0;
274}
275
276
277
278
279static const struct uart_ops altera_jtaguart_ops = {
280 .tx_empty = altera_jtaguart_tx_empty,
281 .get_mctrl = altera_jtaguart_get_mctrl,
282 .set_mctrl = altera_jtaguart_set_mctrl,
283 .start_tx = altera_jtaguart_start_tx,
284 .stop_tx = altera_jtaguart_stop_tx,
285 .stop_rx = altera_jtaguart_stop_rx,
286 .break_ctl = altera_jtaguart_break_ctl,
287 .startup = altera_jtaguart_startup,
288 .shutdown = altera_jtaguart_shutdown,
289 .set_termios = altera_jtaguart_set_termios,
290 .type = altera_jtaguart_type,
291 .request_port = altera_jtaguart_request_port,
292 .release_port = altera_jtaguart_release_port,
293 .config_port = altera_jtaguart_config_port,
294 .verify_port = altera_jtaguart_verify_port,
295};
296
297#define ALTERA_JTAGUART_MAXPORTS 1
298static struct altera_jtaguart altera_jtaguart_ports[ALTERA_JTAGUART_MAXPORTS];
299
300#if defined(CONFIG_SERIAL_ALTERA_JTAGUART_CONSOLE)
301
302#if defined(CONFIG_SERIAL_ALTERA_JTAGUART_CONSOLE_BYPASS)
303static void altera_jtaguart_console_putc(struct uart_port *port, int c)
304{
305 unsigned long status;
306 unsigned long flags;
307
308 spin_lock_irqsave(&port->lock, flags);
309 while (((status = readl(port->membase + ALTERA_JTAGUART_CONTROL_REG)) &
310 ALTERA_JTAGUART_CONTROL_WSPACE_MSK) == 0) {
311 if ((status & ALTERA_JTAGUART_CONTROL_AC_MSK) == 0) {
312 spin_unlock_irqrestore(&port->lock, flags);
313 return;
314 }
315 spin_unlock_irqrestore(&port->lock, flags);
316 cpu_relax();
317 spin_lock_irqsave(&port->lock, flags);
318 }
319 writel(c, port->membase + ALTERA_JTAGUART_DATA_REG);
320 spin_unlock_irqrestore(&port->lock, flags);
321}
322#else
323static void altera_jtaguart_console_putc(struct uart_port *port, int c)
324{
325 unsigned long flags;
326
327 spin_lock_irqsave(&port->lock, flags);
328 while ((readl(port->membase + ALTERA_JTAGUART_CONTROL_REG) &
329 ALTERA_JTAGUART_CONTROL_WSPACE_MSK) == 0) {
330 spin_unlock_irqrestore(&port->lock, flags);
331 cpu_relax();
332 spin_lock_irqsave(&port->lock, flags);
333 }
334 writel(c, port->membase + ALTERA_JTAGUART_DATA_REG);
335 spin_unlock_irqrestore(&port->lock, flags);
336}
337#endif
338
339static void altera_jtaguart_console_write(struct console *co, const char *s,
340 unsigned int count)
341{
342 struct uart_port *port = &(altera_jtaguart_ports + co->index)->port;
343
344 uart_console_write(port, s, count, altera_jtaguart_console_putc);
345}
346
347static int __init altera_jtaguart_console_setup(struct console *co,
348 char *options)
349{
350 struct uart_port *port;
351
352 if (co->index < 0 || co->index >= ALTERA_JTAGUART_MAXPORTS)
353 return -EINVAL;
354 port = &altera_jtaguart_ports[co->index].port;
355 if (port->membase == NULL)
356 return -ENODEV;
357 return 0;
358}
359
360static struct uart_driver altera_jtaguart_driver;
361
362static struct console altera_jtaguart_console = {
363 .name = "ttyJ",
364 .write = altera_jtaguart_console_write,
365 .device = uart_console_device,
366 .setup = altera_jtaguart_console_setup,
367 .flags = CON_PRINTBUFFER,
368 .index = -1,
369 .data = &altera_jtaguart_driver,
370};
371
372static int __init altera_jtaguart_console_init(void)
373{
374 register_console(&altera_jtaguart_console);
375 return 0;
376}
377
378console_initcall(altera_jtaguart_console_init);
379
380#define ALTERA_JTAGUART_CONSOLE (&altera_jtaguart_console)
381
382static void altera_jtaguart_earlycon_write(struct console *co, const char *s,
383 unsigned int count)
384{
385 struct earlycon_device *dev = co->data;
386
387 uart_console_write(&dev->port, s, count, altera_jtaguart_console_putc);
388}
389
390static int __init altera_jtaguart_earlycon_setup(struct earlycon_device *dev,
391 const char *options)
392{
393 if (!dev->port.membase)
394 return -ENODEV;
395
396 dev->con->write = altera_jtaguart_earlycon_write;
397 return 0;
398}
399
400OF_EARLYCON_DECLARE(juart, "altr,juart-1.0", altera_jtaguart_earlycon_setup);
401
402#else
403
404#define ALTERA_JTAGUART_CONSOLE NULL
405
406#endif
407
408static struct uart_driver altera_jtaguart_driver = {
409 .owner = THIS_MODULE,
410 .driver_name = "altera_jtaguart",
411 .dev_name = "ttyJ",
412 .major = ALTERA_JTAGUART_MAJOR,
413 .minor = ALTERA_JTAGUART_MINOR,
414 .nr = ALTERA_JTAGUART_MAXPORTS,
415 .cons = ALTERA_JTAGUART_CONSOLE,
416};
417
418static int altera_jtaguart_probe(struct platform_device *pdev)
419{
420 struct altera_jtaguart_platform_uart *platp =
421 dev_get_platdata(&pdev->dev);
422 struct uart_port *port;
423 struct resource *res_irq, *res_mem;
424 int i = pdev->id;
425
426
427 if (i == -1)
428 i = 0;
429
430 if (i >= ALTERA_JTAGUART_MAXPORTS)
431 return -EINVAL;
432
433 port = &altera_jtaguart_ports[i].port;
434
435 res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
436 if (res_mem)
437 port->mapbase = res_mem->start;
438 else if (platp)
439 port->mapbase = platp->mapbase;
440 else
441 return -ENODEV;
442
443 res_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
444 if (res_irq)
445 port->irq = res_irq->start;
446 else if (platp)
447 port->irq = platp->irq;
448 else
449 return -ENODEV;
450
451 port->membase = ioremap(port->mapbase, ALTERA_JTAGUART_SIZE);
452 if (!port->membase)
453 return -ENOMEM;
454
455 port->line = i;
456 port->type = PORT_ALTERA_JTAGUART;
457 port->iotype = SERIAL_IO_MEM;
458 port->ops = &altera_jtaguart_ops;
459 port->flags = UPF_BOOT_AUTOCONF;
460 port->dev = &pdev->dev;
461
462 uart_add_one_port(&altera_jtaguart_driver, port);
463
464 return 0;
465}
466
467static int altera_jtaguart_remove(struct platform_device *pdev)
468{
469 struct uart_port *port;
470 int i = pdev->id;
471
472 if (i == -1)
473 i = 0;
474
475 port = &altera_jtaguart_ports[i].port;
476 uart_remove_one_port(&altera_jtaguart_driver, port);
477 iounmap(port->membase);
478
479 return 0;
480}
481
482#ifdef CONFIG_OF
483static const struct of_device_id altera_jtaguart_match[] = {
484 { .compatible = "ALTR,juart-1.0", },
485 { .compatible = "altr,juart-1.0", },
486 {},
487};
488MODULE_DEVICE_TABLE(of, altera_jtaguart_match);
489#endif
490
491static struct platform_driver altera_jtaguart_platform_driver = {
492 .probe = altera_jtaguart_probe,
493 .remove = altera_jtaguart_remove,
494 .driver = {
495 .name = DRV_NAME,
496 .of_match_table = of_match_ptr(altera_jtaguart_match),
497 },
498};
499
500static int __init altera_jtaguart_init(void)
501{
502 int rc;
503
504 rc = uart_register_driver(&altera_jtaguart_driver);
505 if (rc)
506 return rc;
507 rc = platform_driver_register(&altera_jtaguart_platform_driver);
508 if (rc)
509 uart_unregister_driver(&altera_jtaguart_driver);
510 return rc;
511}
512
513static void __exit altera_jtaguart_exit(void)
514{
515 platform_driver_unregister(&altera_jtaguart_platform_driver);
516 uart_unregister_driver(&altera_jtaguart_driver);
517}
518
519module_init(altera_jtaguart_init);
520module_exit(altera_jtaguart_exit);
521
522MODULE_DESCRIPTION("Altera JTAG UART driver");
523MODULE_AUTHOR("Thomas Chou <thomas@wytron.com.tw>");
524MODULE_LICENSE("GPL");
525MODULE_ALIAS("platform:" DRV_NAME);
526
