2 * Driver for KS8695 serial ports
4 * Based on drivers/serial/serial_amba.c, by Kam Lee.
6 * Copyright 2002-2005 Micrel Inc.
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
14 #include <linux/module.h>
15 #include <linux/tty.h>
16 #include <linux/tty_flip.h>
17 #include <linux/ioport.h>
18 #include <linux/init.h>
19 #include <linux/serial.h>
20 #include <linux/console.h>
21 #include <linux/sysrq.h>
22 #include <linux/device.h>
26 #include <asm/mach/irq.h>
28 #include <mach/regs-uart.h>
29 #include <mach/regs-irq.h>
31 #if defined(CONFIG_SERIAL_KS8695_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
35 #include <linux/serial_core.h>
38 #define SERIAL_KS8695_MAJOR 204
39 #define SERIAL_KS8695_MINOR 16
40 #define SERIAL_KS8695_DEVNAME "ttyAM"
42 #define SERIAL_KS8695_NR 1
45 * Access macros for the KS8695 UART
47 #define UART_GET_CHAR(p) (__raw_readl((p)->membase + KS8695_URRB) & 0xFF)
48 #define UART_PUT_CHAR(p, c) __raw_writel((c), (p)->membase + KS8695_URTH)
49 #define UART_GET_FCR(p) __raw_readl((p)->membase + KS8695_URFC)
50 #define UART_PUT_FCR(p, c) __raw_writel((c), (p)->membase + KS8695_URFC)
51 #define UART_GET_MSR(p) __raw_readl((p)->membase + KS8695_URMS)
52 #define UART_GET_LSR(p) __raw_readl((p)->membase + KS8695_URLS)
53 #define UART_GET_LCR(p) __raw_readl((p)->membase + KS8695_URLC)
54 #define UART_PUT_LCR(p, c) __raw_writel((c), (p)->membase + KS8695_URLC)
55 #define UART_GET_MCR(p) __raw_readl((p)->membase + KS8695_URMC)
56 #define UART_PUT_MCR(p, c) __raw_writel((c), (p)->membase + KS8695_URMC)
57 #define UART_GET_BRDR(p) __raw_readl((p)->membase + KS8695_URBD)
58 #define UART_PUT_BRDR(p, c) __raw_writel((c), (p)->membase + KS8695_URBD)
60 #define KS8695_CLR_TX_INT() __raw_writel(1 << KS8695_IRQ_UART_TX, KS8695_IRQ_VA + KS8695_INTST)
62 #define UART_DUMMY_LSR_RX 0x100
63 #define UART_PORT_SIZE (KS8695_USR - KS8695_URRB + 4)
65 static inline int tx_enabled(struct uart_port *port)
67 return port->unused[0] & 1;
70 static inline int rx_enabled(struct uart_port *port)
72 return port->unused[0] & 2;
75 static inline int ms_enabled(struct uart_port *port)
77 return port->unused[0] & 4;
80 static inline void ms_enable(struct uart_port *port, int enabled)
85 port->unused[0] &= ~4;
88 static inline void rx_enable(struct uart_port *port, int enabled)
93 port->unused[0] &= ~2;
96 static inline void tx_enable(struct uart_port *port, int enabled)
101 port->unused[0] &= ~1;
106 static struct console ks8695_console;
109 static void ks8695uart_stop_tx(struct uart_port *port)
111 if (tx_enabled(port)) {
112 /* use disable_irq_nosync() and not disable_irq() to avoid self
113 * imposed deadlock by not waiting for irq handler to end,
114 * since this ks8695uart_stop_tx() is called from interrupt context.
116 disable_irq_nosync(KS8695_IRQ_UART_TX);
121 static void ks8695uart_start_tx(struct uart_port *port)
123 if (!tx_enabled(port)) {
124 enable_irq(KS8695_IRQ_UART_TX);
129 static void ks8695uart_stop_rx(struct uart_port *port)
131 if (rx_enabled(port)) {
132 disable_irq(KS8695_IRQ_UART_RX);
137 static void ks8695uart_enable_ms(struct uart_port *port)
139 if (!ms_enabled(port)) {
140 enable_irq(KS8695_IRQ_UART_MODEM_STATUS);
145 static void ks8695uart_disable_ms(struct uart_port *port)
147 if (ms_enabled(port)) {
148 disable_irq(KS8695_IRQ_UART_MODEM_STATUS);
153 static irqreturn_t ks8695uart_rx_chars(int irq, void *dev_id)
155 struct uart_port *port = dev_id;
156 unsigned int status, ch, lsr, flg, max_count = 256;
158 status = UART_GET_LSR(port); /* clears pending LSR interrupts */
159 while ((status & URLS_URDR) && max_count--) {
160 ch = UART_GET_CHAR(port);
166 * Note that the error handling code is
167 * out of the main execution path
169 lsr = UART_GET_LSR(port) | UART_DUMMY_LSR_RX;
170 if (unlikely(lsr & (URLS_URBI | URLS_URPE | URLS_URFE | URLS_URROE))) {
171 if (lsr & URLS_URBI) {
172 lsr &= ~(URLS_URFE | URLS_URPE);
174 if (uart_handle_break(port))
178 port->icount.parity++;
180 port->icount.frame++;
181 if (lsr & URLS_URROE)
182 port->icount.overrun++;
184 lsr &= port->read_status_mask;
188 else if (lsr & URLS_URPE)
190 else if (lsr & URLS_URFE)
194 if (uart_handle_sysrq_char(port, ch))
197 uart_insert_char(port, lsr, URLS_URROE, ch, flg);
200 status = UART_GET_LSR(port);
202 tty_flip_buffer_push(&port->state->port);
208 static irqreturn_t ks8695uart_tx_chars(int irq, void *dev_id)
210 struct uart_port *port = dev_id;
211 struct circ_buf *xmit = &port->state->xmit;
216 UART_PUT_CHAR(port, port->x_char);
222 if (uart_tx_stopped(port) || uart_circ_empty(xmit)) {
223 ks8695uart_stop_tx(port);
227 count = 16; /* fifo size */
228 while (!uart_circ_empty(xmit) && (count-- > 0)) {
230 UART_PUT_CHAR(port, xmit->buf[xmit->tail]);
232 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
236 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
237 uart_write_wakeup(port);
239 if (uart_circ_empty(xmit))
240 ks8695uart_stop_tx(port);
245 static irqreturn_t ks8695uart_modem_status(int irq, void *dev_id)
247 struct uart_port *port = dev_id;
251 * clear modem interrupt by reading MSR
253 status = UART_GET_MSR(port);
255 if (status & URMS_URDDCD)
256 uart_handle_dcd_change(port, status & URMS_URDDCD);
258 if (status & URMS_URDDST)
261 if (status & URMS_URDCTS)
262 uart_handle_cts_change(port, status & URMS_URDCTS);
264 if (status & URMS_URTERI)
267 wake_up_interruptible(&port->state->port.delta_msr_wait);
272 static unsigned int ks8695uart_tx_empty(struct uart_port *port)
274 return (UART_GET_LSR(port) & URLS_URTE) ? TIOCSER_TEMT : 0;
277 static unsigned int ks8695uart_get_mctrl(struct uart_port *port)
279 unsigned int result = 0;
282 status = UART_GET_MSR(port);
283 if (status & URMS_URDCD)
285 if (status & URMS_URDSR)
287 if (status & URMS_URCTS)
289 if (status & URMS_URRI)
295 static void ks8695uart_set_mctrl(struct uart_port *port, u_int mctrl)
299 mcr = UART_GET_MCR(port);
300 if (mctrl & TIOCM_RTS)
305 if (mctrl & TIOCM_DTR)
310 UART_PUT_MCR(port, mcr);
313 static void ks8695uart_break_ctl(struct uart_port *port, int break_state)
317 lcr = UART_GET_LCR(port);
319 if (break_state == -1)
324 UART_PUT_LCR(port, lcr);
327 static int ks8695uart_startup(struct uart_port *port)
331 irq_modify_status(KS8695_IRQ_UART_TX, IRQ_NOREQUEST, IRQ_NOAUTOEN);
339 retval = request_irq(KS8695_IRQ_UART_TX, ks8695uart_tx_chars, 0, "UART TX", port);
343 retval = request_irq(KS8695_IRQ_UART_RX, ks8695uart_rx_chars, 0, "UART RX", port);
347 retval = request_irq(KS8695_IRQ_UART_LINE_STATUS, ks8695uart_rx_chars, 0, "UART LineStatus", port);
351 retval = request_irq(KS8695_IRQ_UART_MODEM_STATUS, ks8695uart_modem_status, 0, "UART ModemStatus", port);
358 free_irq(KS8695_IRQ_UART_LINE_STATUS, port);
360 free_irq(KS8695_IRQ_UART_RX, port);
362 free_irq(KS8695_IRQ_UART_TX, port);
367 static void ks8695uart_shutdown(struct uart_port *port)
372 free_irq(KS8695_IRQ_UART_RX, port);
373 free_irq(KS8695_IRQ_UART_TX, port);
374 free_irq(KS8695_IRQ_UART_MODEM_STATUS, port);
375 free_irq(KS8695_IRQ_UART_LINE_STATUS, port);
377 /* disable break condition and fifos */
378 UART_PUT_LCR(port, UART_GET_LCR(port) & ~URLC_URSBC);
379 UART_PUT_FCR(port, UART_GET_FCR(port) & ~URFC_URFE);
382 static void ks8695uart_set_termios(struct uart_port *port, struct ktermios *termios, struct ktermios *old)
384 unsigned int lcr, fcr = 0;
386 unsigned int baud, quot;
389 * Ask the core to calculate the divisor for us.
391 baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
392 quot = uart_get_divisor(port, baud);
394 switch (termios->c_cflag & CSIZE) {
410 if (termios->c_cflag & CSTOPB)
414 if (termios->c_cflag & PARENB) {
415 if (termios->c_cflag & CMSPAR) { /* Mark or Space parity */
416 if (termios->c_cflag & PARODD)
421 else if (termios->c_cflag & PARODD)
427 if (port->fifosize > 1)
428 fcr = URFC_URFRT_8 | URFC_URTFR | URFC_URRFR | URFC_URFE;
430 spin_lock_irqsave(&port->lock, flags);
433 * Update the per-port timeout.
435 uart_update_timeout(port, termios->c_cflag, baud);
437 port->read_status_mask = URLS_URROE;
438 if (termios->c_iflag & INPCK)
439 port->read_status_mask |= (URLS_URFE | URLS_URPE);
440 if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
441 port->read_status_mask |= URLS_URBI;
444 * Characters to ignore
446 port->ignore_status_mask = 0;
447 if (termios->c_iflag & IGNPAR)
448 port->ignore_status_mask |= (URLS_URFE | URLS_URPE);
449 if (termios->c_iflag & IGNBRK) {
450 port->ignore_status_mask |= URLS_URBI;
452 * If we're ignoring parity and break indicators,
453 * ignore overruns too (for real raw support).
455 if (termios->c_iflag & IGNPAR)
456 port->ignore_status_mask |= URLS_URROE;
460 * Ignore all characters if CREAD is not set.
462 if ((termios->c_cflag & CREAD) == 0)
463 port->ignore_status_mask |= UART_DUMMY_LSR_RX;
465 /* first, disable everything */
466 if (UART_ENABLE_MS(port, termios->c_cflag))
467 ks8695uart_enable_ms(port);
469 ks8695uart_disable_ms(port);
472 UART_PUT_BRDR(port, quot);
474 UART_PUT_LCR(port, lcr);
475 UART_PUT_FCR(port, fcr);
477 spin_unlock_irqrestore(&port->lock, flags);
480 static const char *ks8695uart_type(struct uart_port *port)
482 return port->type == PORT_KS8695 ? "KS8695" : NULL;
486 * Release the memory region(s) being used by 'port'
488 static void ks8695uart_release_port(struct uart_port *port)
490 release_mem_region(port->mapbase, UART_PORT_SIZE);
494 * Request the memory region(s) being used by 'port'
496 static int ks8695uart_request_port(struct uart_port *port)
498 return request_mem_region(port->mapbase, UART_PORT_SIZE,
499 "serial_ks8695") != NULL ? 0 : -EBUSY;
503 * Configure/autoconfigure the port.
505 static void ks8695uart_config_port(struct uart_port *port, int flags)
507 if (flags & UART_CONFIG_TYPE) {
508 port->type = PORT_KS8695;
509 ks8695uart_request_port(port);
514 * verify the new serial_struct (for TIOCSSERIAL).
516 static int ks8695uart_verify_port(struct uart_port *port, struct serial_struct *ser)
520 if (ser->type != PORT_UNKNOWN && ser->type != PORT_KS8695)
522 if (ser->irq != port->irq)
524 if (ser->baud_base < 9600)
529 static struct uart_ops ks8695uart_pops = {
530 .tx_empty = ks8695uart_tx_empty,
531 .set_mctrl = ks8695uart_set_mctrl,
532 .get_mctrl = ks8695uart_get_mctrl,
533 .stop_tx = ks8695uart_stop_tx,
534 .start_tx = ks8695uart_start_tx,
535 .stop_rx = ks8695uart_stop_rx,
536 .enable_ms = ks8695uart_enable_ms,
537 .break_ctl = ks8695uart_break_ctl,
538 .startup = ks8695uart_startup,
539 .shutdown = ks8695uart_shutdown,
540 .set_termios = ks8695uart_set_termios,
541 .type = ks8695uart_type,
542 .release_port = ks8695uart_release_port,
543 .request_port = ks8695uart_request_port,
544 .config_port = ks8695uart_config_port,
545 .verify_port = ks8695uart_verify_port,
548 static struct uart_port ks8695uart_ports[SERIAL_KS8695_NR] = {
550 .membase = KS8695_UART_VA,
551 .mapbase = KS8695_UART_PA,
552 .iotype = SERIAL_IO_MEM,
553 .irq = KS8695_IRQ_UART_TX,
554 .uartclk = KS8695_CLOCK_RATE * 16,
556 .ops = &ks8695uart_pops,
557 .flags = UPF_BOOT_AUTOCONF,
562 #ifdef CONFIG_SERIAL_KS8695_CONSOLE
563 static void ks8695_console_putchar(struct uart_port *port, int ch)
565 while (!(UART_GET_LSR(port) & URLS_URTHRE))
568 UART_PUT_CHAR(port, ch);
571 static void ks8695_console_write(struct console *co, const char *s, u_int count)
573 struct uart_port *port = ks8695uart_ports + co->index;
575 uart_console_write(port, s, count, ks8695_console_putchar);
578 static void __init ks8695_console_get_options(struct uart_port *port, int *baud, int *parity, int *bits)
582 lcr = UART_GET_LCR(port);
584 switch (lcr & URLC_PARITY) {
595 switch (lcr & URLC_URCL) {
609 *baud = port->uartclk / (UART_GET_BRDR(port) & 0x0FFF);
614 static int __init ks8695_console_setup(struct console *co, char *options)
616 struct uart_port *port;
623 * Check whether an invalid uart number has been specified, and
624 * if so, search for the first available port that does have
627 port = uart_get_console(ks8695uart_ports, SERIAL_KS8695_NR, co);
630 uart_parse_options(options, &baud, &parity, &bits, &flow);
632 ks8695_console_get_options(port, &baud, &parity, &bits);
634 return uart_set_options(port, co, baud, parity, bits, flow);
637 static struct uart_driver ks8695_reg;
639 static struct console ks8695_console = {
640 .name = SERIAL_KS8695_DEVNAME,
641 .write = ks8695_console_write,
642 .device = uart_console_device,
643 .setup = ks8695_console_setup,
644 .flags = CON_PRINTBUFFER,
649 static int __init ks8695_console_init(void)
651 add_preferred_console(SERIAL_KS8695_DEVNAME, 0, NULL);
652 register_console(&ks8695_console);
656 console_initcall(ks8695_console_init);
658 #define KS8695_CONSOLE &ks8695_console
660 #define KS8695_CONSOLE NULL
663 static struct uart_driver ks8695_reg = {
664 .owner = THIS_MODULE,
665 .driver_name = "serial_ks8695",
666 .dev_name = SERIAL_KS8695_DEVNAME,
667 .major = SERIAL_KS8695_MAJOR,
668 .minor = SERIAL_KS8695_MINOR,
669 .nr = SERIAL_KS8695_NR,
670 .cons = KS8695_CONSOLE,
673 static int __init ks8695uart_init(void)
677 printk(KERN_INFO "Serial: Micrel KS8695 UART driver\n");
679 ret = uart_register_driver(&ks8695_reg);
683 for (i = 0; i < SERIAL_KS8695_NR; i++)
684 uart_add_one_port(&ks8695_reg, &ks8695uart_ports[0]);
689 static void __exit ks8695uart_exit(void)
693 for (i = 0; i < SERIAL_KS8695_NR; i++)
694 uart_remove_one_port(&ks8695_reg, &ks8695uart_ports[0]);
695 uart_unregister_driver(&ks8695_reg);
698 module_init(ks8695uart_init);
699 module_exit(ks8695uart_exit);
701 MODULE_DESCRIPTION("KS8695 serial port driver");
702 MODULE_AUTHOR("Micrel Inc.");
703 MODULE_LICENSE("GPL");