2 * linux/drivers/serial/pxa.c
4 * Based on drivers/serial/8250.c by Russell King.
6 * Author: Nicolas Pitre
7 * Created: Feb 20, 2003
8 * Copyright: (C) 2003 Monta Vista Software, Inc.
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.
15 * Note 1: This driver is made separate from the already too overloaded
16 * 8250.c because it needs some kirks of its own and that'll make it
17 * easier to add DMA support.
19 * Note 2: I'm too sick of device allocation policies for serial ports.
20 * If someone else wants to request an "official" allocation of major/minor
21 * for this driver please be my guest. And don't forget that new hardware
22 * to come from Intel might have more than 3 or 4 of those UARTs. Let's
23 * hope for a better port registration and dynamic device allocation scheme
24 * with the serial core maintainer satisfaction to appear soon.
27 #include <linux/config.h>
29 #if defined(CONFIG_SERIAL_PXA_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
33 #include <linux/module.h>
34 #include <linux/ioport.h>
35 #include <linux/init.h>
36 #include <linux/console.h>
37 #include <linux/sysrq.h>
38 #include <linux/serial_reg.h>
39 #include <linux/circ_buf.h>
40 #include <linux/delay.h>
41 #include <linux/interrupt.h>
42 #include <linux/device.h>
43 #include <linux/tty.h>
44 #include <linux/tty_flip.h>
45 #include <linux/serial_core.h>
48 #include <asm/hardware.h>
50 #include <asm/arch/pxa-regs.h>
53 struct uart_pxa_port {
54 struct uart_port port;
58 unsigned int lsr_break_flag;
63 static inline unsigned int serial_in(struct uart_pxa_port *up, int offset)
66 return readl(up->port.membase + offset);
69 static inline void serial_out(struct uart_pxa_port *up, int offset, int value)
72 writel(value, up->port.membase + offset);
75 static void serial_pxa_enable_ms(struct uart_port *port)
77 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
79 up->ier |= UART_IER_MSI;
80 serial_out(up, UART_IER, up->ier);
83 static void serial_pxa_stop_tx(struct uart_port *port, unsigned int tty_stop)
85 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
87 if (up->ier & UART_IER_THRI) {
88 up->ier &= ~UART_IER_THRI;
89 serial_out(up, UART_IER, up->ier);
93 static void serial_pxa_stop_rx(struct uart_port *port)
95 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
97 up->ier &= ~UART_IER_RLSI;
98 up->port.read_status_mask &= ~UART_LSR_DR;
99 serial_out(up, UART_IER, up->ier);
103 receive_chars(struct uart_pxa_port *up, int *status, struct pt_regs *regs)
105 struct tty_struct *tty = up->port.info->tty;
106 unsigned int ch, flag;
110 if (unlikely(tty->flip.count >= TTY_FLIPBUF_SIZE)) {
111 if (tty->low_latency)
112 tty_flip_buffer_push(tty);
114 * If this failed then we will throw away the
115 * bytes but must do so to clear interrupts
118 ch = serial_in(up, UART_RX);
120 up->port.icount.rx++;
122 if (unlikely(*status & (UART_LSR_BI | UART_LSR_PE |
123 UART_LSR_FE | UART_LSR_OE))) {
125 * For statistics only
127 if (*status & UART_LSR_BI) {
128 *status &= ~(UART_LSR_FE | UART_LSR_PE);
129 up->port.icount.brk++;
131 * We do the SysRQ and SAK checking
132 * here because otherwise the break
133 * may get masked by ignore_status_mask
134 * or read_status_mask.
136 if (uart_handle_break(&up->port))
138 } else if (*status & UART_LSR_PE)
139 up->port.icount.parity++;
140 else if (*status & UART_LSR_FE)
141 up->port.icount.frame++;
142 if (*status & UART_LSR_OE)
143 up->port.icount.overrun++;
146 * Mask off conditions which should be ignored.
148 *status &= up->port.read_status_mask;
150 #ifdef CONFIG_SERIAL_PXA_CONSOLE
151 if (up->port.line == up->port.cons->index) {
152 /* Recover the break flag from console xmit */
153 *status |= up->lsr_break_flag;
154 up->lsr_break_flag = 0;
157 if (*status & UART_LSR_BI) {
159 } else if (*status & UART_LSR_PE)
161 else if (*status & UART_LSR_FE)
164 if (uart_handle_sysrq_char(&up->port, ch, regs))
166 if ((*status & up->port.ignore_status_mask) == 0) {
167 tty_insert_flip_char(tty, ch, flag);
169 if ((*status & UART_LSR_OE) &&
170 tty->flip.count < TTY_FLIPBUF_SIZE) {
172 * Overrun is special, since it's reported
173 * immediately, and doesn't affect the current
176 tty_insert_flip_char(tty, 0, TTY_OVERRUN);
179 *status = serial_in(up, UART_LSR);
180 } while ((*status & UART_LSR_DR) && (max_count-- > 0));
181 tty_flip_buffer_push(tty);
184 static void transmit_chars(struct uart_pxa_port *up)
186 struct circ_buf *xmit = &up->port.info->xmit;
189 if (up->port.x_char) {
190 serial_out(up, UART_TX, up->port.x_char);
191 up->port.icount.tx++;
195 if (uart_circ_empty(xmit) || uart_tx_stopped(&up->port)) {
196 serial_pxa_stop_tx(&up->port, 0);
200 count = up->port.fifosize / 2;
202 serial_out(up, UART_TX, xmit->buf[xmit->tail]);
203 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
204 up->port.icount.tx++;
205 if (uart_circ_empty(xmit))
207 } while (--count > 0);
209 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
210 uart_write_wakeup(&up->port);
213 if (uart_circ_empty(xmit))
214 serial_pxa_stop_tx(&up->port, 0);
217 static void serial_pxa_start_tx(struct uart_port *port, unsigned int tty_start)
219 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
221 if (!(up->ier & UART_IER_THRI)) {
222 up->ier |= UART_IER_THRI;
223 serial_out(up, UART_IER, up->ier);
227 static inline void check_modem_status(struct uart_pxa_port *up)
231 status = serial_in(up, UART_MSR);
233 if ((status & UART_MSR_ANY_DELTA) == 0)
236 if (status & UART_MSR_TERI)
237 up->port.icount.rng++;
238 if (status & UART_MSR_DDSR)
239 up->port.icount.dsr++;
240 if (status & UART_MSR_DDCD)
241 uart_handle_dcd_change(&up->port, status & UART_MSR_DCD);
242 if (status & UART_MSR_DCTS)
243 uart_handle_cts_change(&up->port, status & UART_MSR_CTS);
245 wake_up_interruptible(&up->port.info->delta_msr_wait);
249 * This handles the interrupt from one port.
251 static inline irqreturn_t
252 serial_pxa_irq(int irq, void *dev_id, struct pt_regs *regs)
254 struct uart_pxa_port *up = (struct uart_pxa_port *)dev_id;
255 unsigned int iir, lsr;
257 iir = serial_in(up, UART_IIR);
258 if (iir & UART_IIR_NO_INT)
260 lsr = serial_in(up, UART_LSR);
261 if (lsr & UART_LSR_DR)
262 receive_chars(up, &lsr, regs);
263 check_modem_status(up);
264 if (lsr & UART_LSR_THRE)
269 static unsigned int serial_pxa_tx_empty(struct uart_port *port)
271 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
275 spin_lock_irqsave(&up->port.lock, flags);
276 ret = serial_in(up, UART_LSR) & UART_LSR_TEMT ? TIOCSER_TEMT : 0;
277 spin_unlock_irqrestore(&up->port.lock, flags);
282 static unsigned int serial_pxa_get_mctrl(struct uart_port *port)
284 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
286 unsigned char status;
289 return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
290 spin_lock_irqsave(&up->port.lock, flags);
291 status = serial_in(up, UART_MSR);
292 spin_unlock_irqrestore(&up->port.lock, flags);
295 if (status & UART_MSR_DCD)
297 if (status & UART_MSR_RI)
299 if (status & UART_MSR_DSR)
301 if (status & UART_MSR_CTS)
306 static void serial_pxa_set_mctrl(struct uart_port *port, unsigned int mctrl)
308 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
309 unsigned char mcr = 0;
311 if (mctrl & TIOCM_RTS)
313 if (mctrl & TIOCM_DTR)
315 if (mctrl & TIOCM_OUT1)
316 mcr |= UART_MCR_OUT1;
317 if (mctrl & TIOCM_OUT2)
318 mcr |= UART_MCR_OUT2;
319 if (mctrl & TIOCM_LOOP)
320 mcr |= UART_MCR_LOOP;
324 serial_out(up, UART_MCR, mcr);
327 static void serial_pxa_break_ctl(struct uart_port *port, int break_state)
329 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
332 spin_lock_irqsave(&up->port.lock, flags);
333 if (break_state == -1)
334 up->lcr |= UART_LCR_SBC;
336 up->lcr &= ~UART_LCR_SBC;
337 serial_out(up, UART_LCR, up->lcr);
338 spin_unlock_irqrestore(&up->port.lock, flags);
342 static void serial_pxa_dma_init(struct pxa_uart *up)
345 pxa_request_dma(up->name, DMA_PRIO_LOW, pxa_receive_dma, up);
349 pxa_request_dma(up->name, DMA_PRIO_LOW, pxa_transmit_dma, up);
352 up->dmadesc = kmalloc(4 * sizeof(pxa_dma_desc), GFP_KERNEL);
358 pxa_free_dma(up->txdma);
360 pxa_free_dma(up->rxdma);
366 static int serial_pxa_startup(struct uart_port *port)
368 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
377 retval = request_irq(up->port.irq, serial_pxa_irq, 0, up->name, up);
382 * Clear the FIFO buffers and disable them.
383 * (they will be reenabled in set_termios())
385 serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO);
386 serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO |
387 UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
388 serial_out(up, UART_FCR, 0);
391 * Clear the interrupt registers.
393 (void) serial_in(up, UART_LSR);
394 (void) serial_in(up, UART_RX);
395 (void) serial_in(up, UART_IIR);
396 (void) serial_in(up, UART_MSR);
399 * Now, initialize the UART
401 serial_out(up, UART_LCR, UART_LCR_WLEN8);
403 spin_lock_irqsave(&up->port.lock, flags);
404 up->port.mctrl |= TIOCM_OUT2;
405 serial_pxa_set_mctrl(&up->port, up->port.mctrl);
406 spin_unlock_irqrestore(&up->port.lock, flags);
409 * Finally, enable interrupts. Note: Modem status interrupts
410 * are set via set_termios(), which will be occuring imminently
411 * anyway, so we don't enable them here.
413 up->ier = UART_IER_RLSI | UART_IER_RDI | UART_IER_RTOIE | UART_IER_UUE;
414 serial_out(up, UART_IER, up->ier);
417 * And clear the interrupt registers again for luck.
419 (void) serial_in(up, UART_LSR);
420 (void) serial_in(up, UART_RX);
421 (void) serial_in(up, UART_IIR);
422 (void) serial_in(up, UART_MSR);
427 static void serial_pxa_shutdown(struct uart_port *port)
429 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
432 free_irq(up->port.irq, up);
435 * Disable interrupts from this port
438 serial_out(up, UART_IER, 0);
440 spin_lock_irqsave(&up->port.lock, flags);
441 up->port.mctrl &= ~TIOCM_OUT2;
442 serial_pxa_set_mctrl(&up->port, up->port.mctrl);
443 spin_unlock_irqrestore(&up->port.lock, flags);
446 * Disable break condition and FIFOs
448 serial_out(up, UART_LCR, serial_in(up, UART_LCR) & ~UART_LCR_SBC);
449 serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO |
450 UART_FCR_CLEAR_RCVR |
451 UART_FCR_CLEAR_XMIT);
452 serial_out(up, UART_FCR, 0);
456 serial_pxa_set_termios(struct uart_port *port, struct termios *termios,
459 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
460 unsigned char cval, fcr = 0;
462 unsigned int baud, quot;
464 switch (termios->c_cflag & CSIZE) {
480 if (termios->c_cflag & CSTOPB)
482 if (termios->c_cflag & PARENB)
483 cval |= UART_LCR_PARITY;
484 if (!(termios->c_cflag & PARODD))
485 cval |= UART_LCR_EPAR;
488 * Ask the core to calculate the divisor for us.
490 baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
491 quot = uart_get_divisor(port, baud);
493 if ((up->port.uartclk / quot) < (2400 * 16))
494 fcr = UART_FCR_ENABLE_FIFO | UART_FCR_PXAR1;
496 fcr = UART_FCR_ENABLE_FIFO | UART_FCR_PXAR8;
499 * Ok, we're now changing the port state. Do it with
500 * interrupts disabled.
502 spin_lock_irqsave(&up->port.lock, flags);
505 * Ensure the port will be enabled.
506 * This is required especially for serial console.
511 * Update the per-port timeout.
513 uart_update_timeout(port, termios->c_cflag, quot);
515 up->port.read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
516 if (termios->c_iflag & INPCK)
517 up->port.read_status_mask |= UART_LSR_FE | UART_LSR_PE;
518 if (termios->c_iflag & (BRKINT | PARMRK))
519 up->port.read_status_mask |= UART_LSR_BI;
522 * Characters to ignore
524 up->port.ignore_status_mask = 0;
525 if (termios->c_iflag & IGNPAR)
526 up->port.ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
527 if (termios->c_iflag & IGNBRK) {
528 up->port.ignore_status_mask |= UART_LSR_BI;
530 * If we're ignoring parity and break indicators,
531 * ignore overruns too (for real raw support).
533 if (termios->c_iflag & IGNPAR)
534 up->port.ignore_status_mask |= UART_LSR_OE;
538 * ignore all characters if CREAD is not set
540 if ((termios->c_cflag & CREAD) == 0)
541 up->port.ignore_status_mask |= UART_LSR_DR;
544 * CTS flow control flag and modem status interrupts
546 up->ier &= ~UART_IER_MSI;
547 if (UART_ENABLE_MS(&up->port, termios->c_cflag))
548 up->ier |= UART_IER_MSI;
550 serial_out(up, UART_IER, up->ier);
552 serial_out(up, UART_LCR, cval | UART_LCR_DLAB);/* set DLAB */
553 serial_out(up, UART_DLL, quot & 0xff); /* LS of divisor */
554 serial_out(up, UART_DLM, quot >> 8); /* MS of divisor */
555 serial_out(up, UART_LCR, cval); /* reset DLAB */
556 up->lcr = cval; /* Save LCR */
557 serial_pxa_set_mctrl(&up->port, up->port.mctrl);
558 serial_out(up, UART_FCR, fcr);
559 spin_unlock_irqrestore(&up->port.lock, flags);
563 serial_pxa_pm(struct uart_port *port, unsigned int state,
564 unsigned int oldstate)
566 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
567 pxa_set_cken(up->cken, !state);
572 static void serial_pxa_release_port(struct uart_port *port)
576 static int serial_pxa_request_port(struct uart_port *port)
581 static void serial_pxa_config_port(struct uart_port *port, int flags)
583 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
584 up->port.type = PORT_PXA;
588 serial_pxa_verify_port(struct uart_port *port, struct serial_struct *ser)
590 /* we don't want the core code to modify any port params */
595 serial_pxa_type(struct uart_port *port)
597 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
601 #ifdef CONFIG_SERIAL_PXA_CONSOLE
603 extern struct uart_pxa_port serial_pxa_ports[];
604 extern struct uart_driver serial_pxa_reg;
606 #define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE)
609 * Wait for transmitter & holding register to empty
611 static inline void wait_for_xmitr(struct uart_pxa_port *up)
613 unsigned int status, tmout = 10000;
615 /* Wait up to 10ms for the character(s) to be sent. */
617 status = serial_in(up, UART_LSR);
619 if (status & UART_LSR_BI)
620 up->lsr_break_flag = UART_LSR_BI;
625 } while ((status & BOTH_EMPTY) != BOTH_EMPTY);
627 /* Wait up to 1s for flow control if necessary */
628 if (up->port.flags & UPF_CONS_FLOW) {
631 ((serial_in(up, UART_MSR) & UART_MSR_CTS) == 0))
637 * Print a string to the serial port trying not to disturb
638 * any possible real use of the port...
640 * The console_lock must be held when we get here.
643 serial_pxa_console_write(struct console *co, const char *s, unsigned int count)
645 struct uart_pxa_port *up = &serial_pxa_ports[co->index];
650 * First save the UER then disable the interrupts
652 ier = serial_in(up, UART_IER);
653 serial_out(up, UART_IER, UART_IER_UUE);
656 * Now, do each character
658 for (i = 0; i < count; i++, s++) {
662 * Send the character out.
663 * If a LF, also do CR...
665 serial_out(up, UART_TX, *s);
668 serial_out(up, UART_TX, 13);
673 * Finally, wait for transmitter to become empty
674 * and restore the IER
677 serial_out(up, UART_IER, ier);
681 serial_pxa_console_setup(struct console *co, char *options)
683 struct uart_pxa_port *up;
689 if (co->index == -1 || co->index >= serial_pxa_reg.nr)
691 up = &serial_pxa_ports[co->index];
694 uart_parse_options(options, &baud, &parity, &bits, &flow);
696 return uart_set_options(&up->port, co, baud, parity, bits, flow);
699 static struct console serial_pxa_console = {
701 .write = serial_pxa_console_write,
702 .device = uart_console_device,
703 .setup = serial_pxa_console_setup,
704 .flags = CON_PRINTBUFFER,
706 .data = &serial_pxa_reg,
710 serial_pxa_console_init(void)
712 register_console(&serial_pxa_console);
716 console_initcall(serial_pxa_console_init);
718 #define PXA_CONSOLE &serial_pxa_console
720 #define PXA_CONSOLE NULL
723 struct uart_ops serial_pxa_pops = {
724 .tx_empty = serial_pxa_tx_empty,
725 .set_mctrl = serial_pxa_set_mctrl,
726 .get_mctrl = serial_pxa_get_mctrl,
727 .stop_tx = serial_pxa_stop_tx,
728 .start_tx = serial_pxa_start_tx,
729 .stop_rx = serial_pxa_stop_rx,
730 .enable_ms = serial_pxa_enable_ms,
731 .break_ctl = serial_pxa_break_ctl,
732 .startup = serial_pxa_startup,
733 .shutdown = serial_pxa_shutdown,
734 .set_termios = serial_pxa_set_termios,
736 .type = serial_pxa_type,
737 .release_port = serial_pxa_release_port,
738 .request_port = serial_pxa_request_port,
739 .config_port = serial_pxa_config_port,
740 .verify_port = serial_pxa_verify_port,
743 static struct uart_pxa_port serial_pxa_ports[] = {
746 .cken = CKEN6_FFUART,
750 .membase = (void *)&FFUART,
751 .mapbase = __PREG(FFUART),
753 .uartclk = 921600 * 16,
755 .ops = &serial_pxa_pops,
760 .cken = CKEN7_BTUART,
764 .membase = (void *)&BTUART,
765 .mapbase = __PREG(BTUART),
767 .uartclk = 921600 * 16,
769 .ops = &serial_pxa_pops,
774 .cken = CKEN5_STUART,
778 .membase = (void *)&STUART,
779 .mapbase = __PREG(STUART),
781 .uartclk = 921600 * 16,
783 .ops = &serial_pxa_pops,
789 static struct uart_driver serial_pxa_reg = {
790 .owner = THIS_MODULE,
791 .driver_name = "PXA serial",
792 .devfs_name = "tts/",
796 .nr = ARRAY_SIZE(serial_pxa_ports),
800 static int serial_pxa_suspend(struct device *_dev, pm_message_t state, u32 level)
802 struct uart_pxa_port *sport = dev_get_drvdata(_dev);
804 if (sport && level == SUSPEND_DISABLE)
805 uart_suspend_port(&serial_pxa_reg, &sport->port);
810 static int serial_pxa_resume(struct device *_dev, u32 level)
812 struct uart_pxa_port *sport = dev_get_drvdata(_dev);
814 if (sport && level == RESUME_ENABLE)
815 uart_resume_port(&serial_pxa_reg, &sport->port);
820 static int serial_pxa_probe(struct device *_dev)
822 struct platform_device *dev = to_platform_device(_dev);
824 serial_pxa_ports[dev->id].port.dev = _dev;
825 uart_add_one_port(&serial_pxa_reg, &serial_pxa_ports[dev->id].port);
826 dev_set_drvdata(_dev, &serial_pxa_ports[dev->id]);
830 static int serial_pxa_remove(struct device *_dev)
832 struct uart_pxa_port *sport = dev_get_drvdata(_dev);
834 dev_set_drvdata(_dev, NULL);
837 uart_remove_one_port(&serial_pxa_reg, &sport->port);
842 static struct device_driver serial_pxa_driver = {
843 .name = "pxa2xx-uart",
844 .bus = &platform_bus_type,
845 .probe = serial_pxa_probe,
846 .remove = serial_pxa_remove,
848 .suspend = serial_pxa_suspend,
849 .resume = serial_pxa_resume,
852 int __init serial_pxa_init(void)
856 ret = uart_register_driver(&serial_pxa_reg);
860 ret = driver_register(&serial_pxa_driver);
862 uart_unregister_driver(&serial_pxa_reg);
867 void __exit serial_pxa_exit(void)
869 driver_unregister(&serial_pxa_driver);
870 uart_unregister_driver(&serial_pxa_reg);
873 module_init(serial_pxa_init);
874 module_exit(serial_pxa_exit);
876 MODULE_LICENSE("GPL");