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>
28 #include <linux/module.h>
29 #include <linux/tty.h>
30 #include <linux/ioport.h>
31 #include <linux/init.h>
32 #include <linux/console.h>
33 #include <linux/sysrq.h>
34 #include <linux/serial_reg.h>
35 #include <linux/circ_buf.h>
36 #include <linux/delay.h>
37 #include <linux/interrupt.h>
38 #include <linux/device.h>
41 #include <asm/hardware.h>
44 #if defined(CONFIG_SERIAL_PXA_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
48 #include <linux/serial_core.h>
51 struct uart_pxa_port {
52 struct uart_port port;
56 unsigned int lsr_break_flag;
61 static inline unsigned int serial_in(struct uart_pxa_port *up, int offset)
64 return readl(up->port.membase + offset);
67 static inline void serial_out(struct uart_pxa_port *up, int offset, int value)
70 writel(value, up->port.membase + offset);
73 static void serial_pxa_enable_ms(struct uart_port *port)
75 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
77 up->ier |= UART_IER_MSI;
78 serial_out(up, UART_IER, up->ier);
81 static void serial_pxa_stop_tx(struct uart_port *port, unsigned int tty_stop)
83 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
85 if (up->ier & UART_IER_THRI) {
86 up->ier &= ~UART_IER_THRI;
87 serial_out(up, UART_IER, up->ier);
91 static void serial_pxa_stop_rx(struct uart_port *port)
93 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
95 up->ier &= ~UART_IER_RLSI;
96 up->port.read_status_mask &= ~UART_LSR_DR;
97 serial_out(up, UART_IER, up->ier);
101 receive_chars(struct uart_pxa_port *up, int *status, struct pt_regs *regs)
103 struct tty_struct *tty = up->port.info->tty;
108 if (unlikely(tty->flip.count >= TTY_FLIPBUF_SIZE)) {
110 * FIXME: Deadlock can happen here if we're a
111 * low-latency port. We're holding the per-port
112 * spinlock, and we call flush_to_ldisc->
113 * n_tty_receive_buf->n_tty_receive_char->
114 * opost->uart_put_char.
116 tty->flip.work.func((void *)tty);
117 if (tty->flip.count >= TTY_FLIPBUF_SIZE)
118 return; // if TTY_DONT_FLIP is set
120 ch = serial_in(up, UART_RX);
121 *tty->flip.char_buf_ptr = ch;
122 *tty->flip.flag_buf_ptr = TTY_NORMAL;
123 up->port.icount.rx++;
125 if (unlikely(*status & (UART_LSR_BI | UART_LSR_PE |
126 UART_LSR_FE | UART_LSR_OE))) {
128 * For statistics only
130 if (*status & UART_LSR_BI) {
131 *status &= ~(UART_LSR_FE | UART_LSR_PE);
132 up->port.icount.brk++;
134 * We do the SysRQ and SAK checking
135 * here because otherwise the break
136 * may get masked by ignore_status_mask
137 * or read_status_mask.
139 if (uart_handle_break(&up->port))
141 } else if (*status & UART_LSR_PE)
142 up->port.icount.parity++;
143 else if (*status & UART_LSR_FE)
144 up->port.icount.frame++;
145 if (*status & UART_LSR_OE)
146 up->port.icount.overrun++;
149 * Mask off conditions which should be ignored.
151 *status &= up->port.read_status_mask;
153 #ifdef CONFIG_SERIAL_PXA_CONSOLE
154 if (up->port.line == up->port.cons->index) {
155 /* Recover the break flag from console xmit */
156 *status |= up->lsr_break_flag;
157 up->lsr_break_flag = 0;
160 if (*status & UART_LSR_BI) {
161 *tty->flip.flag_buf_ptr = TTY_BREAK;
162 } else if (*status & UART_LSR_PE)
163 *tty->flip.flag_buf_ptr = TTY_PARITY;
164 else if (*status & UART_LSR_FE)
165 *tty->flip.flag_buf_ptr = TTY_FRAME;
167 if (uart_handle_sysrq_char(&up->port, ch, regs))
169 if ((*status & up->port.ignore_status_mask) == 0) {
170 tty->flip.flag_buf_ptr++;
171 tty->flip.char_buf_ptr++;
174 if ((*status & UART_LSR_OE) &&
175 tty->flip.count < TTY_FLIPBUF_SIZE) {
177 * Overrun is special, since it's reported
178 * immediately, and doesn't affect the current
181 *tty->flip.flag_buf_ptr = TTY_OVERRUN;
182 tty->flip.flag_buf_ptr++;
183 tty->flip.char_buf_ptr++;
187 *status = serial_in(up, UART_LSR);
188 } while ((*status & UART_LSR_DR) && (max_count-- > 0));
189 tty_flip_buffer_push(tty);
192 static void transmit_chars(struct uart_pxa_port *up)
194 struct circ_buf *xmit = &up->port.info->xmit;
197 if (up->port.x_char) {
198 serial_out(up, UART_TX, up->port.x_char);
199 up->port.icount.tx++;
203 if (uart_circ_empty(xmit) || uart_tx_stopped(&up->port)) {
204 serial_pxa_stop_tx(&up->port, 0);
208 count = up->port.fifosize / 2;
210 serial_out(up, UART_TX, xmit->buf[xmit->tail]);
211 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
212 up->port.icount.tx++;
213 if (uart_circ_empty(xmit))
215 } while (--count > 0);
217 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
218 uart_write_wakeup(&up->port);
221 if (uart_circ_empty(xmit))
222 serial_pxa_stop_tx(&up->port, 0);
225 static void serial_pxa_start_tx(struct uart_port *port, unsigned int tty_start)
227 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
229 if (!(up->ier & UART_IER_THRI)) {
230 up->ier |= UART_IER_THRI;
231 serial_out(up, UART_IER, up->ier);
235 static inline void check_modem_status(struct uart_pxa_port *up)
239 status = serial_in(up, UART_MSR);
241 if ((status & UART_MSR_ANY_DELTA) == 0)
244 if (status & UART_MSR_TERI)
245 up->port.icount.rng++;
246 if (status & UART_MSR_DDSR)
247 up->port.icount.dsr++;
248 if (status & UART_MSR_DDCD)
249 uart_handle_dcd_change(&up->port, status & UART_MSR_DCD);
250 if (status & UART_MSR_DCTS)
251 uart_handle_cts_change(&up->port, status & UART_MSR_CTS);
253 wake_up_interruptible(&up->port.info->delta_msr_wait);
257 * This handles the interrupt from one port.
259 static inline irqreturn_t
260 serial_pxa_irq(int irq, void *dev_id, struct pt_regs *regs)
262 struct uart_pxa_port *up = (struct uart_pxa_port *)dev_id;
263 unsigned int iir, lsr;
265 iir = serial_in(up, UART_IIR);
266 if (iir & UART_IIR_NO_INT)
268 lsr = serial_in(up, UART_LSR);
269 if (lsr & UART_LSR_DR)
270 receive_chars(up, &lsr, regs);
271 check_modem_status(up);
272 if (lsr & UART_LSR_THRE)
277 static unsigned int serial_pxa_tx_empty(struct uart_port *port)
279 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
283 spin_lock_irqsave(&up->port.lock, flags);
284 ret = serial_in(up, UART_LSR) & UART_LSR_TEMT ? TIOCSER_TEMT : 0;
285 spin_unlock_irqrestore(&up->port.lock, flags);
290 static unsigned int serial_pxa_get_mctrl(struct uart_port *port)
292 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
294 unsigned char status;
297 return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
298 spin_lock_irqsave(&up->port.lock, flags);
299 status = serial_in(up, UART_MSR);
300 spin_unlock_irqrestore(&up->port.lock, flags);
303 if (status & UART_MSR_DCD)
305 if (status & UART_MSR_RI)
307 if (status & UART_MSR_DSR)
309 if (status & UART_MSR_CTS)
314 static void serial_pxa_set_mctrl(struct uart_port *port, unsigned int mctrl)
316 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
317 unsigned char mcr = 0;
319 if (mctrl & TIOCM_RTS)
321 if (mctrl & TIOCM_DTR)
323 if (mctrl & TIOCM_OUT1)
324 mcr |= UART_MCR_OUT1;
325 if (mctrl & TIOCM_OUT2)
326 mcr |= UART_MCR_OUT2;
327 if (mctrl & TIOCM_LOOP)
328 mcr |= UART_MCR_LOOP;
332 serial_out(up, UART_MCR, mcr);
335 static void serial_pxa_break_ctl(struct uart_port *port, int break_state)
337 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
340 spin_lock_irqsave(&up->port.lock, flags);
341 if (break_state == -1)
342 up->lcr |= UART_LCR_SBC;
344 up->lcr &= ~UART_LCR_SBC;
345 serial_out(up, UART_LCR, up->lcr);
346 spin_unlock_irqrestore(&up->port.lock, flags);
350 static void serial_pxa_dma_init(struct pxa_uart *up)
353 pxa_request_dma(up->name, DMA_PRIO_LOW, pxa_receive_dma, up);
357 pxa_request_dma(up->name, DMA_PRIO_LOW, pxa_transmit_dma, up);
360 up->dmadesc = kmalloc(4 * sizeof(pxa_dma_desc), GFP_KERNEL);
366 pxa_free_dma(up->txdma);
368 pxa_free_dma(up->rxdma);
374 static int serial_pxa_startup(struct uart_port *port)
376 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
385 retval = request_irq(up->port.irq, serial_pxa_irq, 0, up->name, up);
390 * Clear the FIFO buffers and disable them.
391 * (they will be reenabled in set_termios())
393 serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO);
394 serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO |
395 UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
396 serial_out(up, UART_FCR, 0);
399 * Clear the interrupt registers.
401 (void) serial_in(up, UART_LSR);
402 (void) serial_in(up, UART_RX);
403 (void) serial_in(up, UART_IIR);
404 (void) serial_in(up, UART_MSR);
407 * Now, initialize the UART
409 serial_out(up, UART_LCR, UART_LCR_WLEN8);
411 spin_lock_irqsave(&up->port.lock, flags);
412 up->port.mctrl |= TIOCM_OUT2;
413 serial_pxa_set_mctrl(&up->port, up->port.mctrl);
414 spin_unlock_irqrestore(&up->port.lock, flags);
417 * Finally, enable interrupts. Note: Modem status interrupts
418 * are set via set_termios(), which will be occuring imminently
419 * anyway, so we don't enable them here.
421 up->ier = UART_IER_RLSI | UART_IER_RDI | UART_IER_RTOIE | UART_IER_UUE;
422 serial_out(up, UART_IER, up->ier);
425 * And clear the interrupt registers again for luck.
427 (void) serial_in(up, UART_LSR);
428 (void) serial_in(up, UART_RX);
429 (void) serial_in(up, UART_IIR);
430 (void) serial_in(up, UART_MSR);
435 static void serial_pxa_shutdown(struct uart_port *port)
437 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
440 free_irq(up->port.irq, up);
443 * Disable interrupts from this port
446 serial_out(up, UART_IER, 0);
448 spin_lock_irqsave(&up->port.lock, flags);
449 up->port.mctrl &= ~TIOCM_OUT2;
450 serial_pxa_set_mctrl(&up->port, up->port.mctrl);
451 spin_unlock_irqrestore(&up->port.lock, flags);
454 * Disable break condition and FIFOs
456 serial_out(up, UART_LCR, serial_in(up, UART_LCR) & ~UART_LCR_SBC);
457 serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO |
458 UART_FCR_CLEAR_RCVR |
459 UART_FCR_CLEAR_XMIT);
460 serial_out(up, UART_FCR, 0);
464 serial_pxa_set_termios(struct uart_port *port, struct termios *termios,
467 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
468 unsigned char cval, fcr = 0;
470 unsigned int baud, quot;
472 switch (termios->c_cflag & CSIZE) {
488 if (termios->c_cflag & CSTOPB)
490 if (termios->c_cflag & PARENB)
491 cval |= UART_LCR_PARITY;
492 if (!(termios->c_cflag & PARODD))
493 cval |= UART_LCR_EPAR;
496 * Ask the core to calculate the divisor for us.
498 baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
499 quot = uart_get_divisor(port, baud);
501 if ((up->port.uartclk / quot) < (2400 * 16))
502 fcr = UART_FCR_ENABLE_FIFO | UART_FCR_PXAR1;
504 fcr = UART_FCR_ENABLE_FIFO | UART_FCR_PXAR8;
507 * Ok, we're now changing the port state. Do it with
508 * interrupts disabled.
510 spin_lock_irqsave(&up->port.lock, flags);
513 * Ensure the port will be enabled.
514 * This is required especially for serial console.
519 * Update the per-port timeout.
521 uart_update_timeout(port, termios->c_cflag, quot);
523 up->port.read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
524 if (termios->c_iflag & INPCK)
525 up->port.read_status_mask |= UART_LSR_FE | UART_LSR_PE;
526 if (termios->c_iflag & (BRKINT | PARMRK))
527 up->port.read_status_mask |= UART_LSR_BI;
530 * Characters to ignore
532 up->port.ignore_status_mask = 0;
533 if (termios->c_iflag & IGNPAR)
534 up->port.ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
535 if (termios->c_iflag & IGNBRK) {
536 up->port.ignore_status_mask |= UART_LSR_BI;
538 * If we're ignoring parity and break indicators,
539 * ignore overruns too (for real raw support).
541 if (termios->c_iflag & IGNPAR)
542 up->port.ignore_status_mask |= UART_LSR_OE;
546 * ignore all characters if CREAD is not set
548 if ((termios->c_cflag & CREAD) == 0)
549 up->port.ignore_status_mask |= UART_LSR_DR;
552 * CTS flow control flag and modem status interrupts
554 up->ier &= ~UART_IER_MSI;
555 if (UART_ENABLE_MS(&up->port, termios->c_cflag))
556 up->ier |= UART_IER_MSI;
558 serial_out(up, UART_IER, up->ier);
560 serial_out(up, UART_LCR, cval | UART_LCR_DLAB);/* set DLAB */
561 serial_out(up, UART_DLL, quot & 0xff); /* LS of divisor */
562 serial_out(up, UART_DLM, quot >> 8); /* MS of divisor */
563 serial_out(up, UART_LCR, cval); /* reset DLAB */
564 up->lcr = cval; /* Save LCR */
565 serial_pxa_set_mctrl(&up->port, up->port.mctrl);
566 serial_out(up, UART_FCR, fcr);
567 spin_unlock_irqrestore(&up->port.lock, flags);
571 serial_pxa_pm(struct uart_port *port, unsigned int state,
572 unsigned int oldstate)
574 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
575 pxa_set_cken(up->cken, !state);
580 static void serial_pxa_release_port(struct uart_port *port)
584 static int serial_pxa_request_port(struct uart_port *port)
589 static void serial_pxa_config_port(struct uart_port *port, int flags)
591 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
592 up->port.type = PORT_PXA;
596 serial_pxa_verify_port(struct uart_port *port, struct serial_struct *ser)
598 /* we don't want the core code to modify any port params */
603 serial_pxa_type(struct uart_port *port)
605 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
609 #ifdef CONFIG_SERIAL_PXA_CONSOLE
611 extern struct uart_pxa_port serial_pxa_ports[];
612 extern struct uart_driver serial_pxa_reg;
614 #define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE)
617 * Wait for transmitter & holding register to empty
619 static inline void wait_for_xmitr(struct uart_pxa_port *up)
621 unsigned int status, tmout = 10000;
623 /* Wait up to 10ms for the character(s) to be sent. */
625 status = serial_in(up, UART_LSR);
627 if (status & UART_LSR_BI)
628 up->lsr_break_flag = UART_LSR_BI;
633 } while ((status & BOTH_EMPTY) != BOTH_EMPTY);
635 /* Wait up to 1s for flow control if necessary */
636 if (up->port.flags & UPF_CONS_FLOW) {
639 ((serial_in(up, UART_MSR) & UART_MSR_CTS) == 0))
645 * Print a string to the serial port trying not to disturb
646 * any possible real use of the port...
648 * The console_lock must be held when we get here.
651 serial_pxa_console_write(struct console *co, const char *s, unsigned int count)
653 struct uart_pxa_port *up = &serial_pxa_ports[co->index];
658 * First save the UER then disable the interrupts
660 ier = serial_in(up, UART_IER);
661 serial_out(up, UART_IER, UART_IER_UUE);
664 * Now, do each character
666 for (i = 0; i < count; i++, s++) {
670 * Send the character out.
671 * If a LF, also do CR...
673 serial_out(up, UART_TX, *s);
676 serial_out(up, UART_TX, 13);
681 * Finally, wait for transmitter to become empty
682 * and restore the IER
685 serial_out(up, UART_IER, ier);
689 serial_pxa_console_setup(struct console *co, char *options)
691 struct uart_pxa_port *up;
697 if (co->index == -1 || co->index >= serial_pxa_reg.nr)
699 up = &serial_pxa_ports[co->index];
702 uart_parse_options(options, &baud, &parity, &bits, &flow);
704 return uart_set_options(&up->port, co, baud, parity, bits, flow);
707 static struct console serial_pxa_console = {
709 .write = serial_pxa_console_write,
710 .device = uart_console_device,
711 .setup = serial_pxa_console_setup,
712 .flags = CON_PRINTBUFFER,
714 .data = &serial_pxa_reg,
718 serial_pxa_console_init(void)
720 register_console(&serial_pxa_console);
724 console_initcall(serial_pxa_console_init);
726 #define PXA_CONSOLE &serial_pxa_console
728 #define PXA_CONSOLE NULL
731 struct uart_ops serial_pxa_pops = {
732 .tx_empty = serial_pxa_tx_empty,
733 .set_mctrl = serial_pxa_set_mctrl,
734 .get_mctrl = serial_pxa_get_mctrl,
735 .stop_tx = serial_pxa_stop_tx,
736 .start_tx = serial_pxa_start_tx,
737 .stop_rx = serial_pxa_stop_rx,
738 .enable_ms = serial_pxa_enable_ms,
739 .break_ctl = serial_pxa_break_ctl,
740 .startup = serial_pxa_startup,
741 .shutdown = serial_pxa_shutdown,
742 .set_termios = serial_pxa_set_termios,
744 .type = serial_pxa_type,
745 .release_port = serial_pxa_release_port,
746 .request_port = serial_pxa_request_port,
747 .config_port = serial_pxa_config_port,
748 .verify_port = serial_pxa_verify_port,
751 static struct uart_pxa_port serial_pxa_ports[] = {
754 .cken = CKEN6_FFUART,
758 .membase = (void *)&FFUART,
759 .mapbase = __PREG(FFUART),
761 .uartclk = 921600 * 16,
763 .ops = &serial_pxa_pops,
768 .cken = CKEN7_BTUART,
772 .membase = (void *)&BTUART,
773 .mapbase = __PREG(BTUART),
775 .uartclk = 921600 * 16,
777 .ops = &serial_pxa_pops,
782 .cken = CKEN5_STUART,
786 .membase = (void *)&STUART,
787 .mapbase = __PREG(STUART),
789 .uartclk = 921600 * 16,
791 .ops = &serial_pxa_pops,
797 static struct uart_driver serial_pxa_reg = {
798 .owner = THIS_MODULE,
799 .driver_name = "PXA serial",
800 .devfs_name = "tts/",
804 .nr = ARRAY_SIZE(serial_pxa_ports),
808 static int serial_pxa_suspend(struct device *_dev, u32 state, u32 level)
810 struct uart_pxa_port *sport = dev_get_drvdata(_dev);
812 if (sport && level == SUSPEND_DISABLE)
813 uart_suspend_port(&serial_pxa_reg, &sport->port);
818 static int serial_pxa_resume(struct device *_dev, u32 level)
820 struct uart_pxa_port *sport = dev_get_drvdata(_dev);
822 if (sport && level == RESUME_ENABLE)
823 uart_resume_port(&serial_pxa_reg, &sport->port);
828 static int serial_pxa_probe(struct device *_dev)
830 struct platform_device *dev = to_platform_device(_dev);
832 serial_pxa_ports[dev->id].port.dev = _dev;
833 uart_add_one_port(&serial_pxa_reg, &serial_pxa_ports[dev->id].port);
834 dev_set_drvdata(_dev, &serial_pxa_ports[dev->id]);
838 static int serial_pxa_remove(struct device *_dev)
840 struct uart_pxa_port *sport = dev_get_drvdata(_dev);
842 dev_set_drvdata(_dev, NULL);
845 uart_remove_one_port(&serial_pxa_reg, &sport->port);
850 static struct device_driver serial_pxa_driver = {
851 .name = "pxa2xx-uart",
852 .bus = &platform_bus_type,
853 .probe = serial_pxa_probe,
854 .remove = serial_pxa_remove,
856 .suspend = serial_pxa_suspend,
857 .resume = serial_pxa_resume,
860 int __init serial_pxa_init(void)
864 ret = uart_register_driver(&serial_pxa_reg);
868 ret = driver_register(&serial_pxa_driver);
870 uart_unregister_driver(&serial_pxa_reg);
875 void __exit serial_pxa_exit(void)
877 driver_unregister(&serial_pxa_driver);
878 uart_unregister_driver(&serial_pxa_reg);
881 module_init(serial_pxa_init);
882 module_exit(serial_pxa_exit);
884 MODULE_LICENSE("GPL");