path: root/drivers/serial/m32r_sio.c

/*
 *  m32r_sio.c
 *
 *  Driver for M32R serial ports
 *
 *  Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
 *  Based on drivers/serial/8250.c.
 *
 *  Copyright (C) 2001  Russell King.
 *  Copyright (C) 2004  Hirokazu Takata <takata at linux-m32r.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */

/*
 * A note about mapbase / membase
 *
 *  mapbase is the physical address of the IO port.  Currently, we don't
 *  support this very well, and it may well be dropped from this driver
 *  in future.  As such, mapbase should be NULL.
 *
 *  membase is an 'ioremapped' cookie.  This is compatible with the old
 *  serial.c driver, and is currently the preferred form.
 */

#if defined(CONFIG_SERIAL_M32R_SIO_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
#define SUPPORT_SYSRQ
#endif

#include <linux/module.h>
#include <linux/tty.h>
#include <linux/ioport.h>
#include <linux/init.h>
#include <linux/console.h>
#include <linux/sysrq.h>
#include <linux/serial.h>
#include <linux/serialP.h>
#include <linux/delay.h>

#include <asm/m32r.h>
#include <asm/io.h>
#include <asm/irq.h>

#define PORT_M32R_BASE	PORT_M32R_SIO
#define PORT_INDEX(x)	(x - PORT_M32R_BASE + 1)
#define BAUD_RATE	115200

#include <linux/serial_core.h>
#include "m32r_sio.h"
#include "m32r_sio_reg.h"

/*
 * Debugging.
 */
#if 0
#define DEBUG_AUTOCONF(fmt...)	printk(fmt)
#else
#define DEBUG_AUTOCONF(fmt...)	do { } while (0)
#endif

#if 0
#define DEBUG_INTR(fmt...)	printk(fmt)
#else
#define DEBUG_INTR(fmt...)	do { } while (0)
#endif

#define PASS_LIMIT	256

/*
 * We default to IRQ0 for the "no irq" hack.   Some
 * machine types want others as well - they're free
 * to redefine this in their header file.
 */
#define is_real_interrupt(irq)	((irq) != 0)

#define BASE_BAUD	115200

/* Standard COM flags */
#define STD_COM_FLAGS (UPF_BOOT_AUTOCONF | UPF_SKIP_TEST)

/*
 * SERIAL_PORT_DFNS tells us about built-in ports that have no
 * standard enumeration mechanism.   Platforms that can find all
 * serial ports via mechanisms like ACPI or PCI need not supply it.
 */
#if defined(CONFIG_PLAT_USRV)

#define SERIAL_PORT_DFNS						\
       /* UART  CLK     PORT   IRQ            FLAGS */			\
	{ 0, BASE_BAUD, 0x3F8, PLD_IRQ_UART0, STD_COM_FLAGS }, /* ttyS0 */ \
	{ 0, BASE_BAUD, 0x2F8, PLD_IRQ_UART1, STD_COM_FLAGS }, /* ttyS1 */

#else /* !CONFIG_PLAT_USRV */

#if defined(CONFIG_SERIAL_M32R_PLDSIO)
#define SERIAL_PORT_DFNS						\
	{ 0, BASE_BAUD, ((unsigned long)PLD_ESIO0CR), PLD_IRQ_SIO0_RCV,	\
	  STD_COM_FLAGS }, /* ttyS0 */
#else
#define SERIAL_PORT_DFNS						\
	{ 0, BASE_BAUD, M32R_SIO_OFFSET, M32R_IRQ_SIO0_R,		\
	  STD_COM_FLAGS }, /* ttyS0 */
#endif

#endif /* !CONFIG_PLAT_USRV */

static struct old_serial_port old_serial_port[] = {
	SERIAL_PORT_DFNS
};

#define UART_NR	ARRAY_SIZE(old_serial_port)

struct uart_sio_port {
	struct uart_port	port;
	struct timer_list	timer;		/* "no irq" timer */
	struct list_head	list;		/* ports on this IRQ */
	unsigned short		rev;
	unsigned char		acr;
	unsigned char		ier;
	unsigned char		lcr;
	unsigned char		mcr_mask;	/* mask of user bits */
	unsigned char		mcr_force;	/* mask of forced bits */
	unsigned char		lsr_break_flag;

	/*
	 * We provide a per-port pm hook.
	 */
	void			(*pm)(struct uart_port *port,
				      unsigned int state, unsigned int old);
};

struct irq_info {
	spinlock_t		lock;
	struct list_head	*head;
};

static struct irq_info irq_lists[NR_IRQS];

/*
 * Here we define the default xmit fifo size used for each type of UART.
 */
static const struct serial_uart_config uart_config[] = {
	[PORT_UNKNOWN] = {
		.name			= "unknown",
		.dfl_xmit_fifo_size	= 1,
		.flags			= 0,
	},
	[PORT_INDEX(PORT_M32R_SIO)] = {
		.name			= "M32RSIO",
		.dfl_xmit_fifo_size	= 1,
		.flags			= 0,
	},
};

#ifdef CONFIG_SERIAL_M32R_PLDSIO

#define __sio_in(x) inw((unsigned long)(x))
#define __sio_out(v,x) outw((v),(unsigned long)(x))

static inline void sio_set_baud_rate(unsigned long baud)
{
	unsigned short sbaud;
	sbaud = (boot_cpu_data.bus_clock / (baud * 4))-1;
	__sio_out(sbaud, PLD_ESIO0BAUR);
}

static void sio_reset(void)
{
	unsigned short tmp;

	tmp = __sio_in(PLD_ESIO0RXB);
	tmp = __sio_in(PLD_ESIO0RXB);
	tmp = __sio_in(PLD_ESIO0CR);
	sio_set_baud_rate(BAUD_RATE);
	__sio_out(0x0300, PLD_ESIO0CR);