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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 tty_flip_buffer_push(&port->state->port);
135}
136
137static void altera_jtaguart_tx_chars(struct altera_jtaguart *pp)
138{
139 struct uart_port *port = &pp->port;
140 struct circ_buf *xmit = &port->state->xmit;
141 unsigned int pending, count;
142
143 if (port->x_char) {
144
145 writel(port->x_char, port->membase + ALTERA_JTAGUART_DATA_REG);
146 port->x_char = 0;
147 port->icount.tx++;
148 return;
149 }
150
151 pending = uart_circ_chars_pending(xmit);
152 if (pending > 0) {
153 count = (readl(port->membase + ALTERA_JTAGUART_CONTROL_REG) &
154 ALTERA_JTAGUART_CONTROL_WSPACE_MSK) >>
155 ALTERA_JTAGUART_CONTROL_WSPACE_OFF;
156 if (count > pending)
157 count = pending;
158 if (count > 0) {
159 pending -= count;
160 while (count--) {
161 writel(xmit->buf[xmit->tail],
162 port->membase + ALTERA_JTAGUART_DATA_REG);
163 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
164 port->icount.tx++;
165 }
166 if (pending < WAKEUP_CHARS)
167 uart_write_wakeup(port);
168 }
169 }
170
171 if (pending == 0) {
172 pp->imr &= ~ALTERA_JTAGUART_CONTROL_WE_MSK;
173 writel(pp->imr, port->membase + ALTERA_JTAGUART_CONTROL_REG);
174 }
175}
176
177static irqreturn_t altera_jtaguart_interrupt(int irq, void *data)
178{
179 struct uart_port *port = data;
180 struct altera_jtaguart *pp =
181 container_of(port, struct altera_jtaguart, port);
182 unsigned int isr;
183
184 isr = (readl(port->membase + ALTERA_JTAGUART_CONTROL_REG) >>
185 ALTERA_JTAGUART_CONTROL_RI_OFF) & pp->imr;
186
187 spin_lock(&port->lock);
188
189 if (isr & ALTERA_JTAGUART_CONTROL_RE_MSK)
190 altera_jtaguart_rx_chars(pp);
191 if (isr & ALTERA_JTAGUART_CONTROL_WE_MSK)
192 altera_jtaguart_tx_chars(pp);
193
194 spin_unlock(&port->lock);
195
196 return IRQ_RETVAL(isr);
197}
198
199static void altera_jtaguart_config_port(struct uart_port *port, int flags)
200{
201 port->type = PORT_ALTERA_JTAGUART;
202
203
204 writel(0, port->membase + ALTERA_JTAGUART_CONTROL_REG);
205}
206
207static int altera_jtaguart_startup(struct uart_port *port)
208{
209 struct altera_jtaguart *pp =
210 container_of(port, struct altera_jtaguart, port);
211 unsigned long flags;
212 int ret;
213
214 ret = request_irq(port->irq, altera_jtaguart_interrupt, 0,
215 DRV_NAME, port);
216 if (ret) {
217 pr_err(DRV_NAME ": unable to attach Altera JTAG UART %d "
218 "interrupt vector=%d\n", port->line, port->irq);
219 return ret;
220 }
221
222 spin_lock_irqsave(&port->lock, flags);
223
224
225 pp->imr = ALTERA_JTAGUART_CONTROL_RE_MSK;
226 writel(pp->imr, port->membase + ALTERA_JTAGUART_CONTROL_REG);
227
228 spin_unlock_irqrestore(&port->lock, flags);
229
230 return 0;
231}
232
233static void altera_jtaguart_shutdown(struct uart_port *port)
234{
235 struct altera_jtaguart *pp =
236 container_of(port, struct altera_jtaguart, port);
237 unsigned long flags;
238
239 spin_lock_irqsave(&port->lock, flags);
240
241
242 pp->imr = 0;
243 writel(pp->imr, port->membase + ALTERA_JTAGUART_CONTROL_REG);
244
245 spin_unlock_irqrestore(&port->lock, flags);
246
247 free_irq(port->irq, port);
248}
249
250static const char *altera_jtaguart_type(struct uart_port *port)
251{
252 return (port->type == PORT_ALTERA_JTAGUART) ? "Altera JTAG UART" : NULL;
253}
254
255static int altera_jtaguart_request_port(struct uart_port *port)
256{
257
258 return 0;
259}
260
261static void altera_jtaguart_release_port(struct uart_port *port)
262{
263
264}
265
266static int altera_jtaguart_verify_port(struct uart_port *port,
267 struct serial_struct *ser)
268{
269 if (ser->type != PORT_UNKNOWN && ser->type != PORT_ALTERA_JTAGUART)
270 return -EINVAL;
271 return 0;
272}
273
274
275
276
277static const struct uart_ops altera_jtaguart_ops = {
278 .tx_empty = altera_jtaguart_tx_empty,
279 .get_mctrl = altera_jtaguart_get_mctrl,
280 .set_mctrl = altera_jtaguart_set_mctrl,
281 .start_tx = altera_jtaguart_start_tx,
282 .stop_tx = altera_jtaguart_stop_tx,
283 .stop_rx = altera_jtaguart_stop_rx,
284 .break_ctl = altera_jtaguart_break_ctl,
285 .startup = altera_jtaguart_startup,
286 .shutdown = altera_jtaguart_shutdown,
287 .set_termios = altera_jtaguart_set_termios,
288 .type = altera_jtaguart_type,
289 .request_port = altera_jtaguart_request_port,
290 .release_port = altera_jtaguart_release_port,
291 .config_port = altera_jtaguart_config_port,
292 .verify_port = altera_jtaguart_verify_port,
293};
294
295#define ALTERA_JTAGUART_MAXPORTS 1
296static struct altera_jtaguart altera_jtaguart_ports[ALTERA_JTAGUART_MAXPORTS];
297
298#if defined(CONFIG_SERIAL_ALTERA_JTAGUART_CONSOLE)
299
300#if defined(CONFIG_SERIAL_ALTERA_JTAGUART_CONSOLE_BYPASS)
301static void altera_jtaguart_console_putc(struct uart_port *port, int c)
302{
303 unsigned long status;
304 unsigned long flags;
305
306 spin_lock_irqsave(&port->lock, flags);
307 while (((status = readl(port->membase + ALTERA_JTAGUART_CONTROL_REG)) &
308 ALTERA_JTAGUART_CONTROL_WSPACE_MSK) == 0) {
309 if ((status & ALTERA_JTAGUART_CONTROL_AC_MSK) == 0) {
310 spin_unlock_irqrestore(&port->lock, flags);
311 return;
312 }
313 spin_unlock_irqrestore(&port->lock, flags);
314 cpu_relax();
315 spin_lock_irqsave(&port->lock, flags);
316 }
317 writel(c, port->membase + ALTERA_JTAGUART_DATA_REG);
318 spin_unlock_irqrestore(&port->lock, flags);
319}
320#else
321static void altera_jtaguart_console_putc(struct uart_port *port, int c)
322{
323 unsigned long flags;
324
325 spin_lock_irqsave(&port->lock, flags);
326 while ((readl(port->membase + ALTERA_JTAGUART_CONTROL_REG) &
327 ALTERA_JTAGUART_CONTROL_WSPACE_MSK) == 0) {
328 spin_unlock_irqrestore(&port->lock, flags);
329 cpu_relax();
330 spin_lock_irqsave(&port->lock, flags);
331 }
332 writel(c, port->membase + ALTERA_JTAGUART_DATA_REG);
333 spin_unlock_irqrestore(&port->lock, flags);
334}
335#endif
336
337static void altera_jtaguart_console_write(struct console *co, const char *s,
338 unsigned int count)
339{
340 struct uart_port *port = &(altera_jtaguart_ports + co->index)->port;
341
342 uart_console_write(port, s, count, altera_jtaguart_console_putc);
343}
344
345static int __init altera_jtaguart_console_setup(struct console *co,
346 char *options)
347{
348 struct uart_port *port;
349
350 if (co->index < 0 || co->index >= ALTERA_JTAGUART_MAXPORTS)
351 return -EINVAL;
352 port = &altera_jtaguart_ports[co->index].port;
353 if (port->membase == NULL)
354 return -ENODEV;
355 return 0;
356}
357
358static struct uart_driver altera_jtaguart_driver;
359
360static struct console altera_jtaguart_console = {
361 .name = "ttyJ",
362 .write = altera_jtaguart_console_write,
363 .device = uart_console_device,
364 .setup = altera_jtaguart_console_setup,
365 .flags = CON_PRINTBUFFER,
366 .index = -1,
367 .data = &altera_jtaguart_driver,
368};
369
370static int __init altera_jtaguart_console_init(void)
371{
372 register_console(&altera_jtaguart_console);
373 return 0;
374}
375
376console_initcall(altera_jtaguart_console_init);
377
378#define ALTERA_JTAGUART_CONSOLE (&altera_jtaguart_console)
379
380static void altera_jtaguart_earlycon_write(struct console *co, const char *s,
381 unsigned int count)
382{
383 struct earlycon_device *dev = co->data;
384
385 uart_console_write(&dev->port, s, count, altera_jtaguart_console_putc);
386}
387
388static int __init altera_jtaguart_earlycon_setup(struct earlycon_device *dev,
389 const char *options)
390{
391 if (!dev->port.membase)
392 return -ENODEV;
393
394 dev->con->write = altera_jtaguart_earlycon_write;
395 return 0;
396}
397
398OF_EARLYCON_DECLARE(juart, "altr,juart-1.0", altera_jtaguart_earlycon_setup);
399
400#else
401
402#define ALTERA_JTAGUART_CONSOLE NULL
403
404#endif
405
406static struct uart_driver altera_jtaguart_driver = {
407 .owner = THIS_MODULE,
408 .driver_name = "altera_jtaguart",
409 .dev_name = "ttyJ",
410 .major = ALTERA_JTAGUART_MAJOR,
411 .minor = ALTERA_JTAGUART_MINOR,
412 .nr = ALTERA_JTAGUART_MAXPORTS,
413 .cons = ALTERA_JTAGUART_CONSOLE,
414};
415
416static int altera_jtaguart_probe(struct platform_device *pdev)
417{
418 struct altera_jtaguart_platform_uart *platp =
419 dev_get_platdata(&pdev->dev);
420 struct uart_port *port;
421 struct resource *res_irq, *res_mem;
422 int i = pdev->id;
423
424
425 if (i == -1)
426 i = 0;
427
428 if (i >= ALTERA_JTAGUART_MAXPORTS)
429 return -EINVAL;
430
431 port = &altera_jtaguart_ports[i].port;
432
433 res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
434 if (res_mem)
435 port->mapbase = res_mem->start;
436 else if (platp)
437 port->mapbase = platp->mapbase;
438 else
439 return -ENODEV;
440
441 res_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
442 if (res_irq)
443 port->irq = res_irq->start;
444 else if (platp)
445 port->irq = platp->irq;
446 else
447 return -ENODEV;
448
449 port->membase = ioremap(port->mapbase, ALTERA_JTAGUART_SIZE);
450 if (!port->membase)
451 return -ENOMEM;
452
453 port->line = i;
454 port->type = PORT_ALTERA_JTAGUART;
455 port->iotype = SERIAL_IO_MEM;
456 port->ops = &altera_jtaguart_ops;
457 port->flags = UPF_BOOT_AUTOCONF;
458 port->dev = &pdev->dev;
459
460 uart_add_one_port(&altera_jtaguart_driver, port);
461
462 return 0;
463}
464
465static int altera_jtaguart_remove(struct platform_device *pdev)
466{
467 struct uart_port *port;
468 int i = pdev->id;
469
470 if (i == -1)
471 i = 0;
472
473 port = &altera_jtaguart_ports[i].port;
474 uart_remove_one_port(&altera_jtaguart_driver, port);
475 iounmap(port->membase);
476
477 return 0;
478}
479
480#ifdef CONFIG_OF
481static const struct of_device_id altera_jtaguart_match[] = {
482 { .compatible = "ALTR,juart-1.0", },
483 { .compatible = "altr,juart-1.0", },
484 {},
485};
486MODULE_DEVICE_TABLE(of, altera_jtaguart_match);
487#endif
488
489static struct platform_driver altera_jtaguart_platform_driver = {
490 .probe = altera_jtaguart_probe,
491 .remove = altera_jtaguart_remove,
492 .driver = {
493 .name = DRV_NAME,
494 .of_match_table = of_match_ptr(altera_jtaguart_match),
495 },
496};
497
498static int __init altera_jtaguart_init(void)
499{
500 int rc;
501
502 rc = uart_register_driver(&altera_jtaguart_driver);
503 if (rc)
504 return rc;
505 rc = platform_driver_register(&altera_jtaguart_platform_driver);
506 if (rc)
507 uart_unregister_driver(&altera_jtaguart_driver);
508 return rc;
509}
510
511static void __exit altera_jtaguart_exit(void)
512{
513 platform_driver_unregister(&altera_jtaguart_platform_driver);
514 uart_unregister_driver(&altera_jtaguart_driver);
515}
516
517module_init(altera_jtaguart_init);
518module_exit(altera_jtaguart_exit);
519
520MODULE_DESCRIPTION("Altera JTAG UART driver");
521MODULE_AUTHOR("Thomas Chou <thomas@wytron.com.tw>");
522MODULE_LICENSE("GPL");
523MODULE_ALIAS("platform:" DRV_NAME);
524
