2 * altera_jtaguart.c -- Altera JTAG UART driver
4 * Based on mcf.c -- Freescale ColdFire UART driver
6 * (C) Copyright 2003-2007, Greg Ungerer <gerg@snapgear.com>
7 * (C) Copyright 2008, Thomas Chou <thomas@wytron.com.tw>
8 * (C) Copyright 2010, Tobias Klauser <tklauser@distanz.ch>
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
16 #include <linux/kernel.h>
17 #include <linux/init.h>
18 #include <linux/interrupt.h>
19 #include <linux/module.h>
20 #include <linux/console.h>
22 #include <linux/tty.h>
23 #include <linux/tty_flip.h>
24 #include <linux/serial.h>
25 #include <linux/serial_core.h>
26 #include <linux/platform_device.h>
28 #include <linux/altera_jtaguart.h>
30 #define DRV_NAME "altera_jtaguart"
33 * Altera JTAG UART register definitions according to the Altera JTAG UART
34 * datasheet: http://www.altera.com/literature/hb/nios2/n2cpu_nii51009.pdf
37 #define ALTERA_JTAGUART_SIZE 8
39 #define ALTERA_JTAGUART_DATA_REG 0
41 #define ALTERA_JTAGUART_DATA_DATA_MSK 0x000000FF
42 #define ALTERA_JTAGUART_DATA_RVALID_MSK 0x00008000
43 #define ALTERA_JTAGUART_DATA_RAVAIL_MSK 0xFFFF0000
44 #define ALTERA_JTAGUART_DATA_RAVAIL_OFF 16
46 #define ALTERA_JTAGUART_CONTROL_REG 4
48 #define ALTERA_JTAGUART_CONTROL_RE_MSK 0x00000001
49 #define ALTERA_JTAGUART_CONTROL_WE_MSK 0x00000002
50 #define ALTERA_JTAGUART_CONTROL_RI_MSK 0x00000100
51 #define ALTERA_JTAGUART_CONTROL_RI_OFF 8
52 #define ALTERA_JTAGUART_CONTROL_WI_MSK 0x00000200
53 #define ALTERA_JTAGUART_CONTROL_AC_MSK 0x00000400
54 #define ALTERA_JTAGUART_CONTROL_WSPACE_MSK 0xFFFF0000
55 #define ALTERA_JTAGUART_CONTROL_WSPACE_OFF 16
58 * Local per-uart structure.
60 struct altera_jtaguart {
61 struct uart_port port;
62 unsigned int sigs; /* Local copy of line sigs */
63 unsigned long imr; /* Local IMR mirror */
66 static unsigned int altera_jtaguart_tx_empty(struct uart_port *port)
68 return (readl(port->membase + ALTERA_JTAGUART_CONTROL_REG) &
69 ALTERA_JTAGUART_CONTROL_WSPACE_MSK) ? TIOCSER_TEMT : 0;
72 static unsigned int altera_jtaguart_get_mctrl(struct uart_port *port)
74 return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
77 static void altera_jtaguart_set_mctrl(struct uart_port *port, unsigned int sigs)
81 static void altera_jtaguart_start_tx(struct uart_port *port)
83 struct altera_jtaguart *pp =
84 container_of(port, struct altera_jtaguart, port);
86 pp->imr |= ALTERA_JTAGUART_CONTROL_WE_MSK;
87 writel(pp->imr, port->membase + ALTERA_JTAGUART_CONTROL_REG);
90 static void altera_jtaguart_stop_tx(struct uart_port *port)
92 struct altera_jtaguart *pp =
93 container_of(port, struct altera_jtaguart, port);
95 pp->imr &= ~ALTERA_JTAGUART_CONTROL_WE_MSK;
96 writel(pp->imr, port->membase + ALTERA_JTAGUART_CONTROL_REG);
99 static void altera_jtaguart_stop_rx(struct uart_port *port)
101 struct altera_jtaguart *pp =
102 container_of(port, struct altera_jtaguart, port);
104 pp->imr &= ~ALTERA_JTAGUART_CONTROL_RE_MSK;
105 writel(pp->imr, port->membase + ALTERA_JTAGUART_CONTROL_REG);
108 static void altera_jtaguart_break_ctl(struct uart_port *port, int break_state)
112 static void altera_jtaguart_enable_ms(struct uart_port *port)
116 static void altera_jtaguart_set_termios(struct uart_port *port,
117 struct ktermios *termios,
118 struct ktermios *old)
120 /* Just copy the old termios settings back */
122 tty_termios_copy_hw(termios, old);
125 static void altera_jtaguart_rx_chars(struct altera_jtaguart *pp)
127 struct uart_port *port = &pp->port;
128 unsigned char ch, flag;
129 unsigned long status;
131 while ((status = readl(port->membase + ALTERA_JTAGUART_DATA_REG)) &
132 ALTERA_JTAGUART_DATA_RVALID_MSK) {
133 ch = status & ALTERA_JTAGUART_DATA_DATA_MSK;
137 if (uart_handle_sysrq_char(port, ch))
139 uart_insert_char(port, 0, 0, ch, flag);
142 spin_unlock(&port->lock);
143 tty_flip_buffer_push(&port->state->port);
144 spin_lock(&port->lock);
147 static void altera_jtaguart_tx_chars(struct altera_jtaguart *pp)
149 struct uart_port *port = &pp->port;
150 struct circ_buf *xmit = &port->state->xmit;
151 unsigned int pending, count;
154 /* Send special char - probably flow control */
155 writel(port->x_char, port->membase + ALTERA_JTAGUART_DATA_REG);
161 pending = uart_circ_chars_pending(xmit);
163 count = (readl(port->membase + ALTERA_JTAGUART_CONTROL_REG) &
164 ALTERA_JTAGUART_CONTROL_WSPACE_MSK) >>
165 ALTERA_JTAGUART_CONTROL_WSPACE_OFF;
171 writel(xmit->buf[xmit->tail],
172 port->membase + ALTERA_JTAGUART_DATA_REG);
173 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
176 if (pending < WAKEUP_CHARS)
177 uart_write_wakeup(port);
182 pp->imr &= ~ALTERA_JTAGUART_CONTROL_WE_MSK;
183 writel(pp->imr, port->membase + ALTERA_JTAGUART_CONTROL_REG);
187 static irqreturn_t altera_jtaguart_interrupt(int irq, void *data)
189 struct uart_port *port = data;
190 struct altera_jtaguart *pp =
191 container_of(port, struct altera_jtaguart, port);
194 isr = (readl(port->membase + ALTERA_JTAGUART_CONTROL_REG) >>
195 ALTERA_JTAGUART_CONTROL_RI_OFF) & pp->imr;
197 spin_lock(&port->lock);
199 if (isr & ALTERA_JTAGUART_CONTROL_RE_MSK)
200 altera_jtaguart_rx_chars(pp);
201 if (isr & ALTERA_JTAGUART_CONTROL_WE_MSK)
202 altera_jtaguart_tx_chars(pp);
204 spin_unlock(&port->lock);
206 return IRQ_RETVAL(isr);
209 static void altera_jtaguart_config_port(struct uart_port *port, int flags)
211 port->type = PORT_ALTERA_JTAGUART;
213 /* Clear mask, so no surprise interrupts. */
214 writel(0, port->membase + ALTERA_JTAGUART_CONTROL_REG);
217 static int altera_jtaguart_startup(struct uart_port *port)
219 struct altera_jtaguart *pp =
220 container_of(port, struct altera_jtaguart, port);
224 ret = request_irq(port->irq, altera_jtaguart_interrupt, 0,
227 pr_err(DRV_NAME ": unable to attach Altera JTAG UART %d "
228 "interrupt vector=%d\n", port->line, port->irq);
232 spin_lock_irqsave(&port->lock, flags);
234 /* Enable RX interrupts now */
235 pp->imr = ALTERA_JTAGUART_CONTROL_RE_MSK;
236 writel(pp->imr, port->membase + ALTERA_JTAGUART_CONTROL_REG);
238 spin_unlock_irqrestore(&port->lock, flags);
243 static void altera_jtaguart_shutdown(struct uart_port *port)
245 struct altera_jtaguart *pp =
246 container_of(port, struct altera_jtaguart, port);
249 spin_lock_irqsave(&port->lock, flags);
251 /* Disable all interrupts now */
253 writel(pp->imr, port->membase + ALTERA_JTAGUART_CONTROL_REG);
255 spin_unlock_irqrestore(&port->lock, flags);
257 free_irq(port->irq, port);
260 static const char *altera_jtaguart_type(struct uart_port *port)
262 return (port->type == PORT_ALTERA_JTAGUART) ? "Altera JTAG UART" : NULL;
265 static int altera_jtaguart_request_port(struct uart_port *port)
267 /* UARTs always present */
271 static void altera_jtaguart_release_port(struct uart_port *port)
273 /* Nothing to release... */
276 static int altera_jtaguart_verify_port(struct uart_port *port,
277 struct serial_struct *ser)
279 if (ser->type != PORT_UNKNOWN && ser->type != PORT_ALTERA_JTAGUART)
285 * Define the basic serial functions we support.
287 static struct uart_ops altera_jtaguart_ops = {
288 .tx_empty = altera_jtaguart_tx_empty,
289 .get_mctrl = altera_jtaguart_get_mctrl,
290 .set_mctrl = altera_jtaguart_set_mctrl,
291 .start_tx = altera_jtaguart_start_tx,
292 .stop_tx = altera_jtaguart_stop_tx,
293 .stop_rx = altera_jtaguart_stop_rx,
294 .enable_ms = altera_jtaguart_enable_ms,
295 .break_ctl = altera_jtaguart_break_ctl,
296 .startup = altera_jtaguart_startup,
297 .shutdown = altera_jtaguart_shutdown,
298 .set_termios = altera_jtaguart_set_termios,
299 .type = altera_jtaguart_type,
300 .request_port = altera_jtaguart_request_port,
301 .release_port = altera_jtaguart_release_port,
302 .config_port = altera_jtaguart_config_port,
303 .verify_port = altera_jtaguart_verify_port,
306 #define ALTERA_JTAGUART_MAXPORTS 1
307 static struct altera_jtaguart altera_jtaguart_ports[ALTERA_JTAGUART_MAXPORTS];
309 #if defined(CONFIG_SERIAL_ALTERA_JTAGUART_CONSOLE)
311 #if defined(CONFIG_SERIAL_ALTERA_JTAGUART_CONSOLE_BYPASS)
312 static void altera_jtaguart_console_putc(struct console *co, const char c)
314 struct uart_port *port = &(altera_jtaguart_ports + co->index)->port;
315 unsigned long status;
318 spin_lock_irqsave(&port->lock, flags);
319 while (((status = readl(port->membase + ALTERA_JTAGUART_CONTROL_REG)) &
320 ALTERA_JTAGUART_CONTROL_WSPACE_MSK) == 0) {
321 if ((status & ALTERA_JTAGUART_CONTROL_AC_MSK) == 0) {
322 spin_unlock_irqrestore(&port->lock, flags);
323 return; /* no connection activity */
325 spin_unlock_irqrestore(&port->lock, flags);
327 spin_lock_irqsave(&port->lock, flags);
329 writel(c, port->membase + ALTERA_JTAGUART_DATA_REG);
330 spin_unlock_irqrestore(&port->lock, flags);
333 static void altera_jtaguart_console_putc(struct console *co, const char c)
335 struct uart_port *port = &(altera_jtaguart_ports + co->index)->port;
338 spin_lock_irqsave(&port->lock, flags);
339 while ((readl(port->membase + ALTERA_JTAGUART_CONTROL_REG) &
340 ALTERA_JTAGUART_CONTROL_WSPACE_MSK) == 0) {
341 spin_unlock_irqrestore(&port->lock, flags);
343 spin_lock_irqsave(&port->lock, flags);
345 writel(c, port->membase + ALTERA_JTAGUART_DATA_REG);
346 spin_unlock_irqrestore(&port->lock, flags);
350 static void altera_jtaguart_console_write(struct console *co, const char *s,
353 for (; count; count--, s++) {
354 altera_jtaguart_console_putc(co, *s);
356 altera_jtaguart_console_putc(co, '\r');
360 static int __init altera_jtaguart_console_setup(struct console *co,
363 struct uart_port *port;
365 if (co->index < 0 || co->index >= ALTERA_JTAGUART_MAXPORTS)
367 port = &altera_jtaguart_ports[co->index].port;
368 if (port->membase == NULL)
373 static struct uart_driver altera_jtaguart_driver;
375 static struct console altera_jtaguart_console = {
377 .write = altera_jtaguart_console_write,
378 .device = uart_console_device,
379 .setup = altera_jtaguart_console_setup,
380 .flags = CON_PRINTBUFFER,
382 .data = &altera_jtaguart_driver,
385 static int __init altera_jtaguart_console_init(void)
387 register_console(&altera_jtaguart_console);
391 console_initcall(altera_jtaguart_console_init);
393 #define ALTERA_JTAGUART_CONSOLE (&altera_jtaguart_console)
397 #define ALTERA_JTAGUART_CONSOLE NULL
399 #endif /* CONFIG_ALTERA_JTAGUART_CONSOLE */
401 static struct uart_driver altera_jtaguart_driver = {
402 .owner = THIS_MODULE,
403 .driver_name = "altera_jtaguart",
405 .major = ALTERA_JTAGUART_MAJOR,
406 .minor = ALTERA_JTAGUART_MINOR,
407 .nr = ALTERA_JTAGUART_MAXPORTS,
408 .cons = ALTERA_JTAGUART_CONSOLE,
411 static int altera_jtaguart_probe(struct platform_device *pdev)
413 struct altera_jtaguart_platform_uart *platp =
414 dev_get_platdata(&pdev->dev);
415 struct uart_port *port;
416 struct resource *res_irq, *res_mem;
419 /* -1 emphasizes that the platform must have one port, no .N suffix */
423 if (i >= ALTERA_JTAGUART_MAXPORTS)
426 port = &altera_jtaguart_ports[i].port;
428 res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
430 port->mapbase = res_mem->start;
432 port->mapbase = platp->mapbase;
436 res_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
438 port->irq = res_irq->start;
440 port->irq = platp->irq;
444 port->membase = ioremap(port->mapbase, ALTERA_JTAGUART_SIZE);
449 port->type = PORT_ALTERA_JTAGUART;
450 port->iotype = SERIAL_IO_MEM;
451 port->ops = &altera_jtaguart_ops;
452 port->flags = UPF_BOOT_AUTOCONF;
454 uart_add_one_port(&altera_jtaguart_driver, port);
459 static int altera_jtaguart_remove(struct platform_device *pdev)
461 struct uart_port *port;
467 port = &altera_jtaguart_ports[i].port;
468 uart_remove_one_port(&altera_jtaguart_driver, port);
474 static struct of_device_id altera_jtaguart_match[] = {
475 { .compatible = "ALTR,juart-1.0", },
476 { .compatible = "altr,juart-1.0", },
479 MODULE_DEVICE_TABLE(of, altera_jtaguart_match);
480 #endif /* CONFIG_OF */
482 static struct platform_driver altera_jtaguart_platform_driver = {
483 .probe = altera_jtaguart_probe,
484 .remove = altera_jtaguart_remove,
487 .owner = THIS_MODULE,
488 .of_match_table = of_match_ptr(altera_jtaguart_match),
492 static int __init altera_jtaguart_init(void)
496 rc = uart_register_driver(&altera_jtaguart_driver);
499 rc = platform_driver_register(&altera_jtaguart_platform_driver);
501 uart_unregister_driver(&altera_jtaguart_driver);
505 static void __exit altera_jtaguart_exit(void)
507 platform_driver_unregister(&altera_jtaguart_platform_driver);
508 uart_unregister_driver(&altera_jtaguart_driver);
511 module_init(altera_jtaguart_init);
512 module_exit(altera_jtaguart_exit);
514 MODULE_DESCRIPTION("Altera JTAG UART driver");
515 MODULE_AUTHOR("Thomas Chou <thomas@wytron.com.tw>");
516 MODULE_LICENSE("GPL");
517 MODULE_ALIAS("platform:" DRV_NAME);