serial.c

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/*
 * linux/arch/arm/mach-omap1/serial.c
 *
 * OMAP1 serial support.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
#include <linux/gpio.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/irq.h>
#include <linux/delay.h>
#include <linux/serial.h>
#include <linux/tty.h>
#include <linux/serial_8250.h>
#include <linux/serial_reg.h>
#include <linux/clk.h>
#include <linux/io.h>

#include <asm/mach-types.h>

#include <mach/mux.h>
#include <plat/fpga.h>

#include "pm.h"

static struct clk * uart1_ck;
static struct clk * uart2_ck;
static struct clk * uart3_ck;

static inline unsigned int omap_serial_in(struct plat_serial8250_port *up,
                      int offset)
{
    offset <<= up->regshift;
    return (unsigned int)__raw_readb(up->membase + offset);
}

static inline void omap_serial_outp(struct plat_serial8250_port *p, int offset,
                    int value)
{
    offset <<= p->regshift;
    __raw_writeb(value, p->membase + offset);
}

/*
 * Internal UARTs need to be initialized for the 8250 autoconfig to work
 * properly. Note that the TX watermark initialization may not be needed
 * once the 8250.c watermark handling code is merged.
 */
static void __init omap_serial_reset(struct plat_serial8250_port *p)
{
    omap_serial_outp(p, UART_OMAP_MDR1,
            UART_OMAP_MDR1_DISABLE);    /* disable UART */
    omap_serial_outp(p, UART_OMAP_SCR, 0x08);   /* TX watermark */
    omap_serial_outp(p, UART_OMAP_MDR1,
            UART_OMAP_MDR1_16X_MODE);   /* enable UART */

    if (!cpu_is_omap15xx()) {
        omap_serial_outp(p, UART_OMAP_SYSC, 0x01);
        while (!(omap_serial_in(p, UART_OMAP_SYSC) & 0x01));
    }
}

static struct plat_serial8250_port serial_platform_data[] = {
    {
        .mapbase    = OMAP1_UART1_BASE,
        .irq        = INT_UART1,
        .flags      = UPF_BOOT_AUTOCONF,
        .iotype     = UPIO_MEM,
        .regshift   = 2,
        .uartclk    = OMAP16XX_BASE_BAUD * 16,
    },
    {
        .mapbase    = OMAP1_UART2_BASE,
        .irq        = INT_UART2,
        .flags      = UPF_BOOT_AUTOCONF,
        .iotype     = UPIO_MEM,
        .regshift   = 2,
        .uartclk    = OMAP16XX_BASE_BAUD * 16,
    },
    {
        .mapbase    = OMAP1_UART3_BASE,
        .irq        = INT_UART3,
        .flags      = UPF_BOOT_AUTOCONF,
        .iotype     = UPIO_MEM,
        .regshift   = 2,
        .uartclk    = OMAP16XX_BASE_BAUD * 16,
    },
    { },
};

static struct platform_device serial_device = {
    .name           = "serial8250",
    .id         = PLAT8250_DEV_PLATFORM,
    .dev            = {
        .platform_data  = serial_platform_data,
    },
};

/*
 * Note that on Innovator-1510 UART2 pins conflict with USB2.
 * By default UART2 does not work on Innovator-1510 if you have
 * USB OHCI enabled. To use UART2, you must disable USB2 first.
 */
void __init omap_serial_init(void)
{
    int i;

    if (cpu_is_omap7xx()) {
        serial_platform_data[0].regshift = 0;
        serial_platform_data[1].regshift = 0;
        serial_platform_data[0].irq = INT_7XX_UART_MODEM_1;
        serial_platform_data[1].irq = INT_7XX_UART_MODEM_IRDA_2;
    }

    if (cpu_is_omap15xx()) {
        serial_platform_data[0].uartclk = OMAP1510_BASE_BAUD * 16;
        serial_platform_data[1].uartclk = OMAP1510_BASE_BAUD * 16;
        serial_platform_data[2].uartclk = OMAP1510_BASE_BAUD * 16;
    }

    for (i = 0; i < ARRAY_SIZE(serial_platform_data) - 1; i++) {

        /* Don't look at UARTs higher than 2 for omap7xx */
        if (cpu_is_omap7xx() && i > 1) {
            serial_platform_data[i].membase = NULL;
            serial_platform_data[i].mapbase = 0;
            continue;
        }

        /* Static mapping, never released */
        serial_platform_data[i].membase =
            ioremap(serial_platform_data[i].mapbase, SZ_2K);
        if (!serial_platform_data[i].membase) {
            printk(KERN_ERR "Could not ioremap uart%i\n", i);
            continue;
        }
        switch (i) {
        case 0:
            uart1_ck = clk_get(NULL, "uart1_ck");
            if (IS_ERR(uart1_ck))
                printk("Could not get uart1_ck\n");
            else {
                clk_enable(uart1_ck);
                if (cpu_is_omap15xx())
                    clk_set_rate(uart1_ck, 12000000);
            }
            break;
        case 1:
            uart2_ck = clk_get(NULL, "uart2_ck");
            if (IS_ERR(uart2_ck))
                printk("Could not get uart2_ck\n");
            else {
                clk_enable(uart2_ck);
                if (cpu_is_omap15xx())
                    clk_set_rate(uart2_ck, 12000000);
                else
                    clk_set_rate(uart2_ck, 48000000);
            }
            break;
        case 2:
            uart3_ck = clk_get(NULL, "uart3_ck");
            if (IS_ERR(uart3_ck))
                printk("Could not get uart3_ck\n");
            else {
                clk_enable(uart3_ck);
                if (cpu_is_omap15xx())
                    clk_set_rate(uart3_ck, 12000000);
            }
            break;
        }
        omap_serial_reset(&serial_platform_data[i]);
    }
}

#ifdef CONFIG_OMAP_SERIAL_WAKE

static irqreturn_t omap_serial_wake_interrupt(int irq, void *dev_id)
{
    /* Need to do something with serial port right after wake-up? */
    return IRQ_HANDLED;
}

/*
 * Reroutes serial RX lines to GPIO lines for the duration of
 * sleep to allow waking up the device from serial port even
 * in deep sleep.
 */
void omap_serial_wake_trigger(int enable)
{
    if (!cpu_is_omap16xx())
        return;

    if (uart1_ck != NULL) {
        if (enable)
            omap_cfg_reg(V14_16XX_GPIO37);
        else
            omap_cfg_reg(V14_16XX_UART1_RX);
    }
    if (uart2_ck != NULL) {
        if (enable)
            omap_cfg_reg(R9_16XX_GPIO18);
        else
            omap_cfg_reg(R9_16XX_UART2_RX);
    }
    if (uart3_ck != NULL) {
        if (enable)
            omap_cfg_reg(L14_16XX_GPIO49);
        else
            omap_cfg_reg(L14_16XX_UART3_RX);
    }
}

static void __init omap_serial_set_port_wakeup(int gpio_nr)
{
    int ret;

    ret = gpio_request(gpio_nr, "UART wake");
    if (ret < 0) {
        printk(KERN_ERR "Could not request UART wake GPIO: %i\n",
               gpio_nr);
        return;
    }
    gpio_direction_input(gpio_nr);
    ret = request_irq(gpio_to_irq(gpio_nr), &omap_serial_wake_interrupt,
              IRQF_TRIGGER_RISING, "serial wakeup", NULL);
    if (ret) {
        gpio_free(gpio_nr);
        printk(KERN_ERR "No interrupt for UART wake GPIO: %i\n",
               gpio_nr);
        return;
    }
    enable_irq_wake(gpio_to_irq(gpio_nr));
}

int __init omap_serial_wakeup_init(void)
{
    if (!cpu_is_omap16xx())
        return 0;

    if (uart1_ck != NULL)
        omap_serial_set_port_wakeup(37);
    if (uart2_ck != NULL)
        omap_serial_set_port_wakeup(18);
    if (uart3_ck != NULL)
        omap_serial_set_port_wakeup(49);

    return 0;
}

#endif  /* CONFIG_OMAP_SERIAL_WAKE */

static int __init omap_init(void)
{
    if (!cpu_class_is_omap1())
        return -ENODEV;

    return platform_device_register(&serial_device);
}
arch_initcall(omap_init);