source: src/linux/universal/linux-3.2/arch/mips/lantiq/xway/gpio_stp.c @ 18171

/*
 *  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.
 *
 *  Copyright (C) 2007 John Crispin <blogic@openwrt.org>
 *
 */

#include <linux/slab.h>
#include <linux/init.h>
#include <linux/export.h>
#include <linux/types.h>
#include <linux/platform_device.h>
#include <linux/mutex.h>
#include <linux/io.h>
#include <linux/gpio.h>

#include <lantiq_soc.h>

#define LTQ_STP_CON0            0x00
#define LTQ_STP_CON1            0x04
#define LTQ_STP_CPU0            0x08
#define LTQ_STP_CPU1            0x0C
#define LTQ_STP_AR              0x10

#define LTQ_STP_CON_SWU         (1 << 31)
#define LTQ_STP_2HZ             0
#define LTQ_STP_4HZ             (1 << 23)
#define LTQ_STP_8HZ             (2 << 23)
#define LTQ_STP_10HZ            (3 << 23)
#define LTQ_STP_SPEED_MASK      (0xf << 23)
#define LTQ_STP_UPD_FPI         (1 << 31)
#define LTQ_STP_UPD_MASK        (3 << 30)
#define LTQ_STP_ADSL_SRC        (3 << 24)

#define LTQ_STP_GROUP0          (1 << 0)

#define LTQ_STP_RISING          0
#define LTQ_STP_FALLING         (1 << 26)
#define LTQ_STP_EDGE_MASK       (1 << 26)

#define ltq_stp_r32(reg)        __raw_readl(ltq_stp_membase + reg)
#define ltq_stp_w32(val, reg)   __raw_writel(val, ltq_stp_membase + reg)
#define ltq_stp_w32_mask(clear, set, reg) \
                ltq_w32((ltq_r32(ltq_stp_membase + reg) & ~(clear)) | (set), \
                ltq_stp_membase + (reg))

static int ltq_stp_shadow = 0xffff;
static void __iomem *ltq_stp_membase;

static void ltq_stp_set(struct gpio_chip *chip, unsigned offset, int value)
{
        if (value)
                ltq_stp_shadow |= (1 << offset);
        else
                ltq_stp_shadow &= ~(1 << offset);
        ltq_stp_w32(ltq_stp_shadow, LTQ_STP_CPU0);
}

static int ltq_stp_direction_output(struct gpio_chip *chip, unsigned offset,
        int value)
{
        ltq_stp_set(chip, offset, value);

        return 0;
}

static struct gpio_chip ltq_stp_chip = {
        .label = "ltq_stp",
        .direction_output = ltq_stp_direction_output,
        .set = ltq_stp_set,
        .base = 48,
        .ngpio = 24,
        .can_sleep = 1,
        .owner = THIS_MODULE,
};

static int ltq_stp_hw_init(void)
{
        /* the 3 pins used to control the external stp */
        ltq_gpio_request(4, 1, 0, 1, "stp-st");
        ltq_gpio_request(5, 1, 0, 1, "stp-d");
        ltq_gpio_request(6, 1, 0, 1, "stp-sh");

        /* sane defaults */
        ltq_stp_w32(0, LTQ_STP_AR);
        ltq_stp_w32(0, LTQ_STP_CPU0);
        ltq_stp_w32(0, LTQ_STP_CPU1);
        ltq_stp_w32(LTQ_STP_CON_SWU, LTQ_STP_CON0);
        ltq_stp_w32(0, LTQ_STP_CON1);

        /* rising or falling edge */
        ltq_stp_w32_mask(LTQ_STP_EDGE_MASK, LTQ_STP_FALLING, LTQ_STP_CON0);

        /* per default stp 15-0 are set */
        ltq_stp_w32_mask(0, LTQ_STP_GROUP0, LTQ_STP_CON1);

        /* stp are update periodically by the FPI bus */
        ltq_stp_w32_mask(LTQ_STP_UPD_MASK, LTQ_STP_UPD_FPI, LTQ_STP_CON1);

        /* set stp update speed */
        ltq_stp_w32_mask(LTQ_STP_SPEED_MASK, LTQ_STP_8HZ, LTQ_STP_CON1);

        /* tell the hardware that pin (led) 0 and 1 are controlled
         *  by the dsl arc
         */
        ltq_stp_w32_mask(0, LTQ_STP_ADSL_SRC, LTQ_STP_CON0);

        ltq_pmu_enable(PMU_LED);
        return 0;
}

static int __devinit ltq_stp_probe(struct platform_device *pdev)
{
        struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        int ret = 0;

        if (!res)
                return -ENOENT;
        res = devm_request_mem_region(&pdev->dev, res->start,
                resource_size(res), dev_name(&pdev->dev));
        if (!res) {
                dev_err(&pdev->dev, "failed to request STP memory\n");
                return -EBUSY;
        }
        ltq_stp_membase = devm_ioremap_nocache(&pdev->dev, res->start,
                resource_size(res));
        if (!ltq_stp_membase) {
                dev_err(&pdev->dev, "failed to remap STP memory\n");
                return -ENOMEM;
        }
        ret = gpiochip_add(&ltq_stp_chip);
        if (!ret)
                ret = ltq_stp_hw_init();

        return ret;
}

static struct platform_driver ltq_stp_driver = {
        .probe = ltq_stp_probe,
        .driver = {
                .name = "ltq_stp",
                .owner = THIS_MODULE,
        },
};

int __init ltq_stp_init(void)
{
        int ret = platform_driver_register(&ltq_stp_driver);

        if (ret)
                pr_info("ltq_stp: error registering platfom driver");
        return ret;
}

postcore_initcall(ltq_stp_init);