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 #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)
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);
102 static inline void receive_chars(struct uart_pxa_port *up, int *status)
104 struct tty_struct *tty = up->port.info->port.tty;
105 unsigned int ch, flag;
109 ch = serial_in(up, UART_RX);
111 up->port.icount.rx++;
113 if (unlikely(*status & (UART_LSR_BI | UART_LSR_PE |
114 UART_LSR_FE | UART_LSR_OE))) {
116 * For statistics only
118 if (*status & UART_LSR_BI) {
119 *status &= ~(UART_LSR_FE | UART_LSR_PE);
120 up->port.icount.brk++;
122 * We do the SysRQ and SAK checking
123 * here because otherwise the break
124 * may get masked by ignore_status_mask
125 * or read_status_mask.
127 if (uart_handle_break(&up->port))
129 } else if (*status & UART_LSR_PE)
130 up->port.icount.parity++;
131 else if (*status & UART_LSR_FE)
132 up->port.icount.frame++;
133 if (*status & UART_LSR_OE)
134 up->port.icount.overrun++;
137 * Mask off conditions which should be ignored.
139 *status &= up->port.read_status_mask;
141 #ifdef CONFIG_SERIAL_PXA_CONSOLE
142 if (up->port.line == up->port.cons->index) {
143 /* Recover the break flag from console xmit */
144 *status |= up->lsr_break_flag;
145 up->lsr_break_flag = 0;
148 if (*status & UART_LSR_BI) {
150 } else if (*status & UART_LSR_PE)
152 else if (*status & UART_LSR_FE)
156 if (uart_handle_sysrq_char(&up->port, ch))
159 uart_insert_char(&up->port, *status, UART_LSR_OE, ch, flag);
162 *status = serial_in(up, UART_LSR);
163 } while ((*status & UART_LSR_DR) && (max_count-- > 0));
164 tty_flip_buffer_push(tty);
167 static void transmit_chars(struct uart_pxa_port *up)
169 struct circ_buf *xmit = &up->port.info->xmit;
172 if (up->port.x_char) {
173 serial_out(up, UART_TX, up->port.x_char);
174 up->port.icount.tx++;
178 if (uart_circ_empty(xmit) || uart_tx_stopped(&up->port)) {
179 serial_pxa_stop_tx(&up->port);
183 count = up->port.fifosize / 2;
185 serial_out(up, UART_TX, xmit->buf[xmit->tail]);
186 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
187 up->port.icount.tx++;
188 if (uart_circ_empty(xmit))
190 } while (--count > 0);
192 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
193 uart_write_wakeup(&up->port);
196 if (uart_circ_empty(xmit))
197 serial_pxa_stop_tx(&up->port);
200 static void serial_pxa_start_tx(struct uart_port *port)
202 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
204 if (!(up->ier & UART_IER_THRI)) {
205 up->ier |= UART_IER_THRI;
206 serial_out(up, UART_IER, up->ier);
210 static inline void check_modem_status(struct uart_pxa_port *up)
214 status = serial_in(up, UART_MSR);
216 if ((status & UART_MSR_ANY_DELTA) == 0)
219 if (status & UART_MSR_TERI)
220 up->port.icount.rng++;
221 if (status & UART_MSR_DDSR)
222 up->port.icount.dsr++;
223 if (status & UART_MSR_DDCD)
224 uart_handle_dcd_change(&up->port, status & UART_MSR_DCD);
225 if (status & UART_MSR_DCTS)
226 uart_handle_cts_change(&up->port, status & UART_MSR_CTS);
228 wake_up_interruptible(&up->port.info->delta_msr_wait);
232 * This handles the interrupt from one port.
234 static inline irqreturn_t serial_pxa_irq(int irq, void *dev_id)
236 struct uart_pxa_port *up = dev_id;
237 unsigned int iir, lsr;
239 iir = serial_in(up, UART_IIR);
240 if (iir & UART_IIR_NO_INT)
242 lsr = serial_in(up, UART_LSR);
243 if (lsr & UART_LSR_DR)
244 receive_chars(up, &lsr);
245 check_modem_status(up);
246 if (lsr & UART_LSR_THRE)
251 static unsigned int serial_pxa_tx_empty(struct uart_port *port)
253 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
257 spin_lock_irqsave(&up->port.lock, flags);
258 ret = serial_in(up, UART_LSR) & UART_LSR_TEMT ? TIOCSER_TEMT : 0;
259 spin_unlock_irqrestore(&up->port.lock, flags);
264 static unsigned int serial_pxa_get_mctrl(struct uart_port *port)
266 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
267 unsigned char status;
270 status = serial_in(up, UART_MSR);
273 if (status & UART_MSR_DCD)
275 if (status & UART_MSR_RI)
277 if (status & UART_MSR_DSR)
279 if (status & UART_MSR_CTS)
284 static void serial_pxa_set_mctrl(struct uart_port *port, unsigned int mctrl)
286 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
287 unsigned char mcr = 0;
289 if (mctrl & TIOCM_RTS)
291 if (mctrl & TIOCM_DTR)
293 if (mctrl & TIOCM_OUT1)
294 mcr |= UART_MCR_OUT1;
295 if (mctrl & TIOCM_OUT2)
296 mcr |= UART_MCR_OUT2;
297 if (mctrl & TIOCM_LOOP)
298 mcr |= UART_MCR_LOOP;
302 serial_out(up, UART_MCR, mcr);
305 static void serial_pxa_break_ctl(struct uart_port *port, int break_state)
307 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
310 spin_lock_irqsave(&up->port.lock, flags);
311 if (break_state == -1)
312 up->lcr |= UART_LCR_SBC;
314 up->lcr &= ~UART_LCR_SBC;
315 serial_out(up, UART_LCR, up->lcr);
316 spin_unlock_irqrestore(&up->port.lock, flags);
320 static void serial_pxa_dma_init(struct pxa_uart *up)
323 pxa_request_dma(up->name, DMA_PRIO_LOW, pxa_receive_dma, up);
327 pxa_request_dma(up->name, DMA_PRIO_LOW, pxa_transmit_dma, up);
330 up->dmadesc = kmalloc(4 * sizeof(pxa_dma_desc), GFP_KERNEL);
336 pxa_free_dma(up->txdma);
338 pxa_free_dma(up->rxdma);
344 static int serial_pxa_startup(struct uart_port *port)
346 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
350 if (port->line == 3) /* HWUART */
351 up->mcr |= UART_MCR_AFE;
355 up->port.uartclk = clk_get_rate(up->clk);
360 retval = request_irq(up->port.irq, serial_pxa_irq, 0, up->name, up);
365 * Clear the FIFO buffers and disable them.
366 * (they will be reenabled in set_termios())
368 serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO);
369 serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO |
370 UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
371 serial_out(up, UART_FCR, 0);
374 * Clear the interrupt registers.
376 (void) serial_in(up, UART_LSR);
377 (void) serial_in(up, UART_RX);
378 (void) serial_in(up, UART_IIR);
379 (void) serial_in(up, UART_MSR);
382 * Now, initialize the UART
384 serial_out(up, UART_LCR, UART_LCR_WLEN8);
386 spin_lock_irqsave(&up->port.lock, flags);
387 up->port.mctrl |= TIOCM_OUT2;
388 serial_pxa_set_mctrl(&up->port, up->port.mctrl);
389 spin_unlock_irqrestore(&up->port.lock, flags);
392 * Finally, enable interrupts. Note: Modem status interrupts
393 * are set via set_termios(), which will be occurring imminently
394 * anyway, so we don't enable them here.
396 up->ier = UART_IER_RLSI | UART_IER_RDI | UART_IER_RTOIE | UART_IER_UUE;
397 serial_out(up, UART_IER, up->ier);
400 * And clear the interrupt registers again for luck.
402 (void) serial_in(up, UART_LSR);
403 (void) serial_in(up, UART_RX);
404 (void) serial_in(up, UART_IIR);
405 (void) serial_in(up, UART_MSR);
410 static void serial_pxa_shutdown(struct uart_port *port)
412 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
415 free_irq(up->port.irq, up);
418 * Disable interrupts from this port
421 serial_out(up, UART_IER, 0);
423 spin_lock_irqsave(&up->port.lock, flags);
424 up->port.mctrl &= ~TIOCM_OUT2;
425 serial_pxa_set_mctrl(&up->port, up->port.mctrl);
426 spin_unlock_irqrestore(&up->port.lock, flags);
429 * Disable break condition and FIFOs
431 serial_out(up, UART_LCR, serial_in(up, UART_LCR) & ~UART_LCR_SBC);
432 serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO |
433 UART_FCR_CLEAR_RCVR |
434 UART_FCR_CLEAR_XMIT);
435 serial_out(up, UART_FCR, 0);
439 serial_pxa_set_termios(struct uart_port *port, struct ktermios *termios,
440 struct ktermios *old)
442 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
443 unsigned char cval, fcr = 0;
445 unsigned int baud, quot;
447 switch (termios->c_cflag & CSIZE) {
449 cval = UART_LCR_WLEN5;
452 cval = UART_LCR_WLEN6;
455 cval = UART_LCR_WLEN7;
459 cval = UART_LCR_WLEN8;
463 if (termios->c_cflag & CSTOPB)
464 cval |= UART_LCR_STOP;
465 if (termios->c_cflag & PARENB)
466 cval |= UART_LCR_PARITY;
467 if (!(termios->c_cflag & PARODD))
468 cval |= UART_LCR_EPAR;
471 * Ask the core to calculate the divisor for us.
473 baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
474 quot = uart_get_divisor(port, baud);
476 if ((up->port.uartclk / quot) < (2400 * 16))
477 fcr = UART_FCR_ENABLE_FIFO | UART_FCR_PXAR1;
478 else if ((up->port.uartclk / quot) < (230400 * 16))
479 fcr = UART_FCR_ENABLE_FIFO | UART_FCR_PXAR8;
481 fcr = UART_FCR_ENABLE_FIFO | UART_FCR_PXAR32;
484 * Ok, we're now changing the port state. Do it with
485 * interrupts disabled.
487 spin_lock_irqsave(&up->port.lock, flags);
490 * Ensure the port will be enabled.
491 * This is required especially for serial console.
496 * Update the per-port timeout.
498 uart_update_timeout(port, termios->c_cflag, baud);
500 up->port.read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
501 if (termios->c_iflag & INPCK)
502 up->port.read_status_mask |= UART_LSR_FE | UART_LSR_PE;
503 if (termios->c_iflag & (BRKINT | PARMRK))
504 up->port.read_status_mask |= UART_LSR_BI;
507 * Characters to ignore
509 up->port.ignore_status_mask = 0;
510 if (termios->c_iflag & IGNPAR)
511 up->port.ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
512 if (termios->c_iflag & IGNBRK) {
513 up->port.ignore_status_mask |= UART_LSR_BI;
515 * If we're ignoring parity and break indicators,
516 * ignore overruns too (for real raw support).
518 if (termios->c_iflag & IGNPAR)
519 up->port.ignore_status_mask |= UART_LSR_OE;
523 * ignore all characters if CREAD is not set
525 if ((termios->c_cflag & CREAD) == 0)
526 up->port.ignore_status_mask |= UART_LSR_DR;
529 * CTS flow control flag and modem status interrupts
531 up->ier &= ~UART_IER_MSI;
532 if (UART_ENABLE_MS(&up->port, termios->c_cflag))
533 up->ier |= UART_IER_MSI;
535 serial_out(up, UART_IER, up->ier);
537 serial_out(up, UART_LCR, cval | UART_LCR_DLAB);/* set DLAB */
538 serial_out(up, UART_DLL, quot & 0xff); /* LS of divisor */
539 serial_out(up, UART_DLM, quot >> 8); /* MS of divisor */
540 serial_out(up, UART_LCR, cval); /* reset DLAB */
541 up->lcr = cval; /* Save LCR */
542 serial_pxa_set_mctrl(&up->port, up->port.mctrl);
543 serial_out(up, UART_FCR, fcr);
544 spin_unlock_irqrestore(&up->port.lock, flags);
548 serial_pxa_pm(struct uart_port *port, unsigned int state,
549 unsigned int oldstate)
551 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
556 clk_disable(up->clk);
559 static void serial_pxa_release_port(struct uart_port *port)
563 static int serial_pxa_request_port(struct uart_port *port)
568 static void serial_pxa_config_port(struct uart_port *port, int flags)
570 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
571 up->port.type = PORT_PXA;
575 serial_pxa_verify_port(struct uart_port *port, struct serial_struct *ser)
577 /* we don't want the core code to modify any port params */
582 serial_pxa_type(struct uart_port *port)
584 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
588 static struct uart_pxa_port *serial_pxa_ports[4];
589 static struct uart_driver serial_pxa_reg;
591 #ifdef CONFIG_SERIAL_PXA_CONSOLE
593 #define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE)
596 * Wait for transmitter & holding register to empty
598 static inline void wait_for_xmitr(struct uart_pxa_port *up)
600 unsigned int status, tmout = 10000;
602 /* Wait up to 10ms for the character(s) to be sent. */
604 status = serial_in(up, UART_LSR);
606 if (status & UART_LSR_BI)
607 up->lsr_break_flag = UART_LSR_BI;
612 } while ((status & BOTH_EMPTY) != BOTH_EMPTY);
614 /* Wait up to 1s for flow control if necessary */
615 if (up->port.flags & UPF_CONS_FLOW) {
618 ((serial_in(up, UART_MSR) & UART_MSR_CTS) == 0))
623 static void serial_pxa_console_putchar(struct uart_port *port, int ch)
625 struct uart_pxa_port *up = (struct uart_pxa_port *)port;
628 serial_out(up, UART_TX, ch);
632 * Print a string to the serial port trying not to disturb
633 * any possible real use of the port...
635 * The console_lock must be held when we get here.
638 serial_pxa_console_write(struct console *co, const char *s, unsigned int count)
640 struct uart_pxa_port *up = serial_pxa_ports[co->index];
646 * First save the IER then disable the interrupts
648 ier = serial_in(up, UART_IER);
649 serial_out(up, UART_IER, UART_IER_UUE);
651 uart_console_write(&up->port, s, count, serial_pxa_console_putchar);
654 * Finally, wait for transmitter to become empty
655 * and restore the IER
658 serial_out(up, UART_IER, ier);
660 clk_disable(up->clk);
664 serial_pxa_console_setup(struct console *co, char *options)
666 struct uart_pxa_port *up;
672 if (co->index == -1 || co->index >= serial_pxa_reg.nr)
674 up = serial_pxa_ports[co->index];
679 uart_parse_options(options, &baud, &parity, &bits, &flow);
681 return uart_set_options(&up->port, co, baud, parity, bits, flow);
684 static struct console serial_pxa_console = {
686 .write = serial_pxa_console_write,
687 .device = uart_console_device,
688 .setup = serial_pxa_console_setup,
689 .flags = CON_PRINTBUFFER,
691 .data = &serial_pxa_reg,
694 #define PXA_CONSOLE &serial_pxa_console
696 #define PXA_CONSOLE NULL
699 struct uart_ops serial_pxa_pops = {
700 .tx_empty = serial_pxa_tx_empty,
701 .set_mctrl = serial_pxa_set_mctrl,
702 .get_mctrl = serial_pxa_get_mctrl,
703 .stop_tx = serial_pxa_stop_tx,
704 .start_tx = serial_pxa_start_tx,
705 .stop_rx = serial_pxa_stop_rx,
706 .enable_ms = serial_pxa_enable_ms,
707 .break_ctl = serial_pxa_break_ctl,
708 .startup = serial_pxa_startup,
709 .shutdown = serial_pxa_shutdown,
710 .set_termios = serial_pxa_set_termios,
712 .type = serial_pxa_type,
713 .release_port = serial_pxa_release_port,
714 .request_port = serial_pxa_request_port,
715 .config_port = serial_pxa_config_port,
716 .verify_port = serial_pxa_verify_port,
719 static struct uart_driver serial_pxa_reg = {
720 .owner = THIS_MODULE,
721 .driver_name = "PXA serial",
729 static int serial_pxa_suspend(struct platform_device *dev, pm_message_t state)
731 struct uart_pxa_port *sport = platform_get_drvdata(dev);
734 uart_suspend_port(&serial_pxa_reg, &sport->port);
739 static int serial_pxa_resume(struct platform_device *dev)
741 struct uart_pxa_port *sport = platform_get_drvdata(dev);
744 uart_resume_port(&serial_pxa_reg, &sport->port);
749 static int serial_pxa_probe(struct platform_device *dev)
751 struct uart_pxa_port *sport;
752 struct resource *mmres, *irqres;
755 mmres = platform_get_resource(dev, IORESOURCE_MEM, 0);
756 irqres = platform_get_resource(dev, IORESOURCE_IRQ, 0);
757 if (!mmres || !irqres)
760 sport = kzalloc(sizeof(struct uart_pxa_port), GFP_KERNEL);
764 sport->clk = clk_get(&dev->dev, "UARTCLK");
765 if (IS_ERR(sport->clk)) {
766 ret = PTR_ERR(sport->clk);
770 sport->port.type = PORT_PXA;
771 sport->port.iotype = UPIO_MEM;
772 sport->port.mapbase = mmres->start;
773 sport->port.irq = irqres->start;
774 sport->port.fifosize = 64;
775 sport->port.ops = &serial_pxa_pops;
776 sport->port.line = dev->id;
777 sport->port.dev = &dev->dev;
778 sport->port.flags = UPF_IOREMAP | UPF_BOOT_AUTOCONF;
779 sport->port.uartclk = clk_get_rate(sport->clk);
782 * Is it worth keeping this?
784 if (mmres->start == __PREG(FFUART))
785 sport->name = "FFUART";
786 else if (mmres->start == __PREG(BTUART))
787 sport->name = "BTUART";
788 else if (mmres->start == __PREG(STUART))
789 sport->name = "STUART";
790 else if (mmres->start == __PREG(HWUART))
791 sport->name = "HWUART";
795 sport->port.membase = ioremap(mmres->start, mmres->end - mmres->start + 1);
796 if (!sport->port.membase) {
801 serial_pxa_ports[dev->id] = sport;
803 uart_add_one_port(&serial_pxa_reg, &sport->port);
804 platform_set_drvdata(dev, sport);
815 static int serial_pxa_remove(struct platform_device *dev)
817 struct uart_pxa_port *sport = platform_get_drvdata(dev);
819 platform_set_drvdata(dev, NULL);
821 uart_remove_one_port(&serial_pxa_reg, &sport->port);
828 static struct platform_driver serial_pxa_driver = {
829 .probe = serial_pxa_probe,
830 .remove = serial_pxa_remove,
832 .suspend = serial_pxa_suspend,
833 .resume = serial_pxa_resume,
835 .name = "pxa2xx-uart",
836 .owner = THIS_MODULE,
840 int __init serial_pxa_init(void)
844 ret = uart_register_driver(&serial_pxa_reg);
848 ret = platform_driver_register(&serial_pxa_driver);
850 uart_unregister_driver(&serial_pxa_reg);
855 void __exit serial_pxa_exit(void)
857 platform_driver_unregister(&serial_pxa_driver);
858 uart_unregister_driver(&serial_pxa_reg);
861 module_init(serial_pxa_init);
862 module_exit(serial_pxa_exit);
864 MODULE_LICENSE("GPL");
865 MODULE_ALIAS("platform:pxa2xx-uart");