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.
28 #if defined(CONFIG_SERIAL_PXA_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
32 #include <linux/module.h>
33 #include <linux/ioport.h>
34 #include <linux/init.h>
35 #include <linux/console.h>
36 #include <linux/sysrq.h>
37 #include <linux/serial_reg.h>
38 #include <linux/circ_buf.h>
39 #include <linux/delay.h>
40 #include <linux/interrupt.h>
41 #include <linux/platform_device.h>
42 #include <linux/tty.h>
43 #include <linux/tty_flip.h>
44 #include <linux/serial_core.h>
45 #include <linux/clk.h>
48 struct uart_pxa_port {
49 struct uart_port port;
53 unsigned int lsr_break_flag;
58 static inline unsigned int serial_in(struct uart_pxa_port *up, int offset)
61 return readl(up->port.membase + offset);
64 static inline void serial_out(struct uart_pxa_port *up, int offset, int value)
67 writel(value, up->port.membase + offset);
70 static void serial_pxa_enable_ms(struct uart_port *port)
72 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
74 up->ier |= UART_IER_MSI;
75 serial_out(up, UART_IER, up->ier);
78 static void serial_pxa_stop_tx(struct uart_port *port)
80 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
82 if (up->ier & UART_IER_THRI) {
83 up->ier &= ~UART_IER_THRI;
84 serial_out(up, UART_IER, up->ier);
88 static void serial_pxa_stop_rx(struct uart_port *port)
90 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
92 up->ier &= ~UART_IER_RLSI;
93 up->port.read_status_mask &= ~UART_LSR_DR;
94 serial_out(up, UART_IER, up->ier);
97 static inline void receive_chars(struct uart_pxa_port *up, int *status)
99 struct tty_struct *tty = up->port.state->port.tty;
100 unsigned int ch, flag;
104 ch = serial_in(up, UART_RX);
106 up->port.icount.rx++;
108 if (unlikely(*status & (UART_LSR_BI | UART_LSR_PE |
109 UART_LSR_FE | UART_LSR_OE))) {
111 * For statistics only
113 if (*status & UART_LSR_BI) {
114 *status &= ~(UART_LSR_FE | UART_LSR_PE);
115 up->port.icount.brk++;
117 * We do the SysRQ and SAK checking
118 * here because otherwise the break
119 * may get masked by ignore_status_mask
120 * or read_status_mask.
122 if (uart_handle_break(&up->port))
124 } else if (*status & UART_LSR_PE)
125 up->port.icount.parity++;
126 else if (*status & UART_LSR_FE)
127 up->port.icount.frame++;
128 if (*status & UART_LSR_OE)
129 up->port.icount.overrun++;
132 * Mask off conditions which should be ignored.
134 *status &= up->port.read_status_mask;
136 #ifdef CONFIG_SERIAL_PXA_CONSOLE
137 if (up->port.line == up->port.cons->index) {
138 /* Recover the break flag from console xmit */
139 *status |= up->lsr_break_flag;
140 up->lsr_break_flag = 0;
143 if (*status & UART_LSR_BI) {
145 } else if (*status & UART_LSR_PE)
147 else if (*status & UART_LSR_FE)
151 if (uart_handle_sysrq_char(&up->port, ch))
154 uart_insert_char(&up->port, *status, UART_LSR_OE, ch, flag);
157 *status = serial_in(up, UART_LSR);
158 } while ((*status & UART_LSR_DR) && (max_count-- > 0));
159 tty_flip_buffer_push(tty);
162 static void transmit_chars(struct uart_pxa_port *up)
164 struct circ_buf *xmit = &up->port.state->xmit;
167 if (up->port.x_char) {
168 serial_out(up, UART_TX, up->port.x_char);
169 up->port.icount.tx++;
173 if (uart_circ_empty(xmit) || uart_tx_stopped(&up->port)) {
174 serial_pxa_stop_tx(&up->port);
178 count = up->port.fifosize / 2;
180 serial_out(up, UART_TX, xmit->buf[xmit->tail]);
181 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
182 up->port.icount.tx++;
183 if (uart_circ_empty(xmit))
185 } while (--count > 0);
187 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
188 uart_write_wakeup(&up->port);
191 if (uart_circ_empty(xmit))
192 serial_pxa_stop_tx(&up->port);
195 static void serial_pxa_start_tx(struct uart_port *port)
197 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
199 if (!(up->ier & UART_IER_THRI)) {
200 up->ier |= UART_IER_THRI;
201 serial_out(up, UART_IER, up->ier);
205 static inline void check_modem_status(struct uart_pxa_port *up)
209 status = serial_in(up, UART_MSR);
211 if ((status & UART_MSR_ANY_DELTA) == 0)
214 if (status & UART_MSR_TERI)
215 up->port.icount.rng++;
216 if (status & UART_MSR_DDSR)
217 up->port.icount.dsr++;
218 if (status & UART_MSR_DDCD)
219 uart_handle_dcd_change(&up->port, status & UART_MSR_DCD);
220 if (status & UART_MSR_DCTS)
221 uart_handle_cts_change(&up->port, status & UART_MSR_CTS);
223 wake_up_interruptible(&up->port.state->port.delta_msr_wait);
227 * This handles the interrupt from one port.
229 static inline irqreturn_t serial_pxa_irq(int irq, void *dev_id)
231 struct uart_pxa_port *up = dev_id;
232 unsigned int iir, lsr;
234 iir = serial_in(up, UART_IIR);
235 if (iir & UART_IIR_NO_INT)
237 lsr = serial_in(up, UART_LSR);
238 if (lsr & UART_LSR_DR)
239 receive_chars(up, &lsr);
240 check_modem_status(up);
241 if (lsr & UART_LSR_THRE)
246 static unsigned int serial_pxa_tx_empty(struct uart_port *port)
248 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
252 spin_lock_irqsave(&up->port.lock, flags);
253 ret = serial_in(up, UART_LSR) & UART_LSR_TEMT ? TIOCSER_TEMT : 0;
254 spin_unlock_irqrestore(&up->port.lock, flags);
259 static unsigned int serial_pxa_get_mctrl(struct uart_port *port)
261 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
262 unsigned char status;
265 status = serial_in(up, UART_MSR);
268 if (status & UART_MSR_DCD)
270 if (status & UART_MSR_RI)
272 if (status & UART_MSR_DSR)
274 if (status & UART_MSR_CTS)
279 static void serial_pxa_set_mctrl(struct uart_port *port, unsigned int mctrl)
281 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
282 unsigned char mcr = 0;
284 if (mctrl & TIOCM_RTS)
286 if (mctrl & TIOCM_DTR)
288 if (mctrl & TIOCM_OUT1)
289 mcr |= UART_MCR_OUT1;
290 if (mctrl & TIOCM_OUT2)
291 mcr |= UART_MCR_OUT2;
292 if (mctrl & TIOCM_LOOP)
293 mcr |= UART_MCR_LOOP;
297 serial_out(up, UART_MCR, mcr);
300 static void serial_pxa_break_ctl(struct uart_port *port, int break_state)
302 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
305 spin_lock_irqsave(&up->port.lock, flags);
306 if (break_state == -1)
307 up->lcr |= UART_LCR_SBC;
309 up->lcr &= ~UART_LCR_SBC;
310 serial_out(up, UART_LCR, up->lcr);
311 spin_unlock_irqrestore(&up->port.lock, flags);
315 static void serial_pxa_dma_init(struct pxa_uart *up)
318 pxa_request_dma(up->name, DMA_PRIO_LOW, pxa_receive_dma, up);
322 pxa_request_dma(up->name, DMA_PRIO_LOW, pxa_transmit_dma, up);
325 up->dmadesc = kmalloc(4 * sizeof(pxa_dma_desc), GFP_KERNEL);
331 pxa_free_dma(up->txdma);
333 pxa_free_dma(up->rxdma);
339 static int serial_pxa_startup(struct uart_port *port)
341 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
345 if (port->line == 3) /* HWUART */
346 up->mcr |= UART_MCR_AFE;
350 up->port.uartclk = clk_get_rate(up->clk);
355 retval = request_irq(up->port.irq, serial_pxa_irq, 0, up->name, up);
360 * Clear the FIFO buffers and disable them.
361 * (they will be reenabled in set_termios())
363 serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO);
364 serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO |
365 UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
366 serial_out(up, UART_FCR, 0);
369 * Clear the interrupt registers.
371 (void) serial_in(up, UART_LSR);
372 (void) serial_in(up, UART_RX);
373 (void) serial_in(up, UART_IIR);
374 (void) serial_in(up, UART_MSR);
377 * Now, initialize the UART
379 serial_out(up, UART_LCR, UART_LCR_WLEN8);
381 spin_lock_irqsave(&up->port.lock, flags);
382 up->port.mctrl |= TIOCM_OUT2;
383 serial_pxa_set_mctrl(&up->port, up->port.mctrl);
384 spin_unlock_irqrestore(&up->port.lock, flags);
387 * Finally, enable interrupts. Note: Modem status interrupts
388 * are set via set_termios(), which will be occurring imminently
389 * anyway, so we don't enable them here.
391 up->ier = UART_IER_RLSI | UART_IER_RDI | UART_IER_RTOIE | UART_IER_UUE;
392 serial_out(up, UART_IER, up->ier);
395 * And clear the interrupt registers again for luck.
397 (void) serial_in(up, UART_LSR);
398 (void) serial_in(up, UART_RX);
399 (void) serial_in(up, UART_IIR);
400 (void) serial_in(up, UART_MSR);
405 static void serial_pxa_shutdown(struct uart_port *port)
407 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
410 free_irq(up->port.irq, up);
413 * Disable interrupts from this port
416 serial_out(up, UART_IER, 0);
418 spin_lock_irqsave(&up->port.lock, flags);
419 up->port.mctrl &= ~TIOCM_OUT2;
420 serial_pxa_set_mctrl(&up->port, up->port.mctrl);
421 spin_unlock_irqrestore(&up->port.lock, flags);
424 * Disable break condition and FIFOs
426 serial_out(up, UART_LCR, serial_in(up, UART_LCR) & ~UART_LCR_SBC);
427 serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO |
428 UART_FCR_CLEAR_RCVR |
429 UART_FCR_CLEAR_XMIT);
430 serial_out(up, UART_FCR, 0);
434 serial_pxa_set_termios(struct uart_port *port, struct ktermios *termios,
435 struct ktermios *old)
437 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
438 unsigned char cval, fcr = 0;
440 unsigned int baud, quot;
443 switch (termios->c_cflag & CSIZE) {
445 cval = UART_LCR_WLEN5;
448 cval = UART_LCR_WLEN6;
451 cval = UART_LCR_WLEN7;
455 cval = UART_LCR_WLEN8;
459 if (termios->c_cflag & CSTOPB)
460 cval |= UART_LCR_STOP;
461 if (termios->c_cflag & PARENB)
462 cval |= UART_LCR_PARITY;
463 if (!(termios->c_cflag & PARODD))
464 cval |= UART_LCR_EPAR;
467 * Ask the core to calculate the divisor for us.
469 baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
470 quot = uart_get_divisor(port, baud);
472 if ((up->port.uartclk / quot) < (2400 * 16))
473 fcr = UART_FCR_ENABLE_FIFO | UART_FCR_PXAR1;
474 else if ((up->port.uartclk / quot) < (230400 * 16))
475 fcr = UART_FCR_ENABLE_FIFO | UART_FCR_PXAR8;
477 fcr = UART_FCR_ENABLE_FIFO | UART_FCR_PXAR32;
480 * Ok, we're now changing the port state. Do it with
481 * interrupts disabled.
483 spin_lock_irqsave(&up->port.lock, flags);
486 * Ensure the port will be enabled.
487 * This is required especially for serial console.
489 up->ier |= UART_IER_UUE;
492 * Update the per-port timeout.
494 uart_update_timeout(port, termios->c_cflag, baud);
496 up->port.read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
497 if (termios->c_iflag & INPCK)
498 up->port.read_status_mask |= UART_LSR_FE | UART_LSR_PE;
499 if (termios->c_iflag & (BRKINT | PARMRK))
500 up->port.read_status_mask |= UART_LSR_BI;
503 * Characters to ignore
505 up->port.ignore_status_mask = 0;
506 if (termios->c_iflag & IGNPAR)
507 up->port.ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
508 if (termios->c_iflag & IGNBRK) {
509 up->port.ignore_status_mask |= UART_LSR_BI;
511 * If we're ignoring parity and break indicators,
512 * ignore overruns too (for real raw support).
514 if (termios->c_iflag & IGNPAR)
515 up->port.ignore_status_mask |= UART_LSR_OE;
519 * ignore all characters if CREAD is not set
521 if ((termios->c_cflag & CREAD) == 0)
522 up->port.ignore_status_mask |= UART_LSR_DR;
525 * CTS flow control flag and modem status interrupts
527 up->ier &= ~UART_IER_MSI;
528 if (UART_ENABLE_MS(&up->port, termios->c_cflag))
529 up->ier |= UART_IER_MSI;
531 serial_out(up, UART_IER, up->ier);
533 if (termios->c_cflag & CRTSCTS)
534 up->mcr |= UART_MCR_AFE;
536 up->mcr &= ~UART_MCR_AFE;
538 serial_out(up, UART_LCR, cval | UART_LCR_DLAB); /* set DLAB */
539 serial_out(up, UART_DLL, quot & 0xff); /* LS of divisor */
542 * work around Errata #75 according to Intel(R) PXA27x Processor Family
543 * Specification Update (Nov 2005)
545 dll = serial_in(up, UART_DLL);
546 WARN_ON(dll != (quot & 0xff));
548 serial_out(up, UART_DLM, quot >> 8); /* MS of divisor */
549 serial_out(up, UART_LCR, cval); /* reset DLAB */
550 up->lcr = cval; /* Save LCR */
551 serial_pxa_set_mctrl(&up->port, up->port.mctrl);
552 serial_out(up, UART_FCR, fcr);
553 spin_unlock_irqrestore(&up->port.lock, flags);
557 serial_pxa_pm(struct uart_port *port, unsigned int state,
558 unsigned int oldstate)
560 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
565 clk_disable(up->clk);
568 static void serial_pxa_release_port(struct uart_port *port)
572 static int serial_pxa_request_port(struct uart_port *port)
577 static void serial_pxa_config_port(struct uart_port *port, int flags)
579 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
580 up->port.type = PORT_PXA;
584 serial_pxa_verify_port(struct uart_port *port, struct serial_struct *ser)
586 /* we don't want the core code to modify any port params */
591 serial_pxa_type(struct uart_port *port)
593 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
597 static struct uart_pxa_port *serial_pxa_ports[4];
598 static struct uart_driver serial_pxa_reg;
600 #ifdef CONFIG_SERIAL_PXA_CONSOLE
602 #define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE)
605 * Wait for transmitter & holding register to empty
607 static inline void wait_for_xmitr(struct uart_pxa_port *up)
609 unsigned int status, tmout = 10000;
611 /* Wait up to 10ms for the character(s) to be sent. */
613 status = serial_in(up, UART_LSR);
615 if (status & UART_LSR_BI)
616 up->lsr_break_flag = UART_LSR_BI;
621 } while ((status & BOTH_EMPTY) != BOTH_EMPTY);
623 /* Wait up to 1s for flow control if necessary */
624 if (up->port.flags & UPF_CONS_FLOW) {
627 ((serial_in(up, UART_MSR) & UART_MSR_CTS) == 0))
632 static void serial_pxa_console_putchar(struct uart_port *port, int ch)
634 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
637 serial_out(up, UART_TX, ch);
641 * Print a string to the serial port trying not to disturb
642 * any possible real use of the port...
644 * The console_lock must be held when we get here.
647 serial_pxa_console_write(struct console *co, const char *s, unsigned int count)
649 struct uart_pxa_port *up = serial_pxa_ports[co->index];
655 * First save the IER then disable the interrupts
657 ier = serial_in(up, UART_IER);
658 serial_out(up, UART_IER, UART_IER_UUE);
660 uart_console_write(&up->port, s, count, serial_pxa_console_putchar);
663 * Finally, wait for transmitter to become empty
664 * and restore the IER
667 serial_out(up, UART_IER, ier);
669 clk_disable(up->clk);
673 serial_pxa_console_setup(struct console *co, char *options)
675 struct uart_pxa_port *up;
681 if (co->index == -1 || co->index >= serial_pxa_reg.nr)
683 up = serial_pxa_ports[co->index];
688 uart_parse_options(options, &baud, &parity, &bits, &flow);
690 return uart_set_options(&up->port, co, baud, parity, bits, flow);
693 static struct console serial_pxa_console = {
695 .write = serial_pxa_console_write,
696 .device = uart_console_device,
697 .setup = serial_pxa_console_setup,
698 .flags = CON_PRINTBUFFER,
700 .data = &serial_pxa_reg,
703 #define PXA_CONSOLE &serial_pxa_console
705 #define PXA_CONSOLE NULL
708 struct uart_ops serial_pxa_pops = {
709 .tx_empty = serial_pxa_tx_empty,
710 .set_mctrl = serial_pxa_set_mctrl,
711 .get_mctrl = serial_pxa_get_mctrl,
712 .stop_tx = serial_pxa_stop_tx,
713 .start_tx = serial_pxa_start_tx,
714 .stop_rx = serial_pxa_stop_rx,
715 .enable_ms = serial_pxa_enable_ms,
716 .break_ctl = serial_pxa_break_ctl,
717 .startup = serial_pxa_startup,
718 .shutdown = serial_pxa_shutdown,
719 .set_termios = serial_pxa_set_termios,
721 .type = serial_pxa_type,
722 .release_port = serial_pxa_release_port,
723 .request_port = serial_pxa_request_port,
724 .config_port = serial_pxa_config_port,
725 .verify_port = serial_pxa_verify_port,
728 static struct uart_driver serial_pxa_reg = {
729 .owner = THIS_MODULE,
730 .driver_name = "PXA serial",
739 static int serial_pxa_suspend(struct device *dev)
741 struct uart_pxa_port *sport = dev_get_drvdata(dev);
744 uart_suspend_port(&serial_pxa_reg, &sport->port);
749 static int serial_pxa_resume(struct device *dev)
751 struct uart_pxa_port *sport = dev_get_drvdata(dev);
754 uart_resume_port(&serial_pxa_reg, &sport->port);
759 static const struct dev_pm_ops serial_pxa_pm_ops = {
760 .suspend = serial_pxa_suspend,
761 .resume = serial_pxa_resume,
765 static int serial_pxa_probe(struct platform_device *dev)
767 struct uart_pxa_port *sport;
768 struct resource *mmres, *irqres;
771 mmres = platform_get_resource(dev, IORESOURCE_MEM, 0);
772 irqres = platform_get_resource(dev, IORESOURCE_IRQ, 0);
773 if (!mmres || !irqres)
776 sport = kzalloc(sizeof(struct uart_pxa_port), GFP_KERNEL);
780 sport->clk = clk_get(&dev->dev, NULL);
781 if (IS_ERR(sport->clk)) {
782 ret = PTR_ERR(sport->clk);
786 sport->port.type = PORT_PXA;
787 sport->port.iotype = UPIO_MEM;
788 sport->port.mapbase = mmres->start;
789 sport->port.irq = irqres->start;
790 sport->port.fifosize = 64;
791 sport->port.ops = &serial_pxa_pops;
792 sport->port.line = dev->id;
793 sport->port.dev = &dev->dev;
794 sport->port.flags = UPF_IOREMAP | UPF_BOOT_AUTOCONF;
795 sport->port.uartclk = clk_get_rate(sport->clk);
798 case 0: sport->name = "FFUART"; break;
799 case 1: sport->name = "BTUART"; break;
800 case 2: sport->name = "STUART"; break;
801 case 3: sport->name = "HWUART"; break;
807 sport->port.membase = ioremap(mmres->start, mmres->end - mmres->start + 1);
808 if (!sport->port.membase) {
813 serial_pxa_ports[dev->id] = sport;
815 uart_add_one_port(&serial_pxa_reg, &sport->port);
816 platform_set_drvdata(dev, sport);
827 static int serial_pxa_remove(struct platform_device *dev)
829 struct uart_pxa_port *sport = platform_get_drvdata(dev);
831 platform_set_drvdata(dev, NULL);
833 uart_remove_one_port(&serial_pxa_reg, &sport->port);
840 static struct platform_driver serial_pxa_driver = {
841 .probe = serial_pxa_probe,
842 .remove = serial_pxa_remove,
845 .name = "pxa2xx-uart",
846 .owner = THIS_MODULE,
848 .pm = &serial_pxa_pm_ops,
853 int __init serial_pxa_init(void)
857 ret = uart_register_driver(&serial_pxa_reg);
861 ret = platform_driver_register(&serial_pxa_driver);
863 uart_unregister_driver(&serial_pxa_reg);
868 void __exit serial_pxa_exit(void)
870 platform_driver_unregister(&serial_pxa_driver);
871 uart_unregister_driver(&serial_pxa_reg);
874 module_init(serial_pxa_init);
875 module_exit(serial_pxa_exit);
877 MODULE_LICENSE("GPL");
878 MODULE_ALIAS("platform:pxa2xx-uart");