htc-pasic3.c

Go to the documentation of this file.

/*
 * Core driver for HTC PASIC3 LED/DS1WM chip.
 *
 * Copyright (C) 2006 Philipp Zabel <[email protected]>
 *
 * 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; version 2 of the License.
 */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/platform_device.h>

#include <linux/gpio.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/interrupt.h>
#include <linux/mfd/core.h>
#include <linux/mfd/ds1wm.h>
#include <linux/mfd/htc-pasic3.h>
#include <linux/slab.h>

struct pasic3_data {
    void __iomem *mapping;
    unsigned int bus_shift;
};

#define REG_ADDR  5
#define REG_DATA  6

#define READ_MODE 0x80

/*
 * write to a secondary register on the PASIC3
 */
void pasic3_write_register(struct device *dev, u32 reg, u8 val)
{
    struct pasic3_data *asic = dev_get_drvdata(dev);
    int bus_shift = asic->bus_shift;
    void __iomem *addr = asic->mapping + (REG_ADDR << bus_shift);
    void __iomem *data = asic->mapping + (REG_DATA << bus_shift);

    __raw_writeb(~READ_MODE & reg, addr);
    __raw_writeb(val, data);
}
EXPORT_SYMBOL(pasic3_write_register); /* for leds-pasic3 */

/*
 * read from a secondary register on the PASIC3
 */
u8 pasic3_read_register(struct device *dev, u32 reg)
{
    struct pasic3_data *asic = dev_get_drvdata(dev);
    int bus_shift = asic->bus_shift;
    void __iomem *addr = asic->mapping + (REG_ADDR << bus_shift);
    void __iomem *data = asic->mapping + (REG_DATA << bus_shift);

    __raw_writeb(READ_MODE | reg, addr);
    return __raw_readb(data);
}
EXPORT_SYMBOL(pasic3_read_register); /* for leds-pasic3 */

/*
 * LEDs
 */

static struct mfd_cell led_cell __initdata = {
    .name = "leds-pasic3",
};

/*
 * DS1WM
 */

static int ds1wm_enable(struct platform_device *pdev)
{
    struct device *dev = pdev->dev.parent;
    int c;

    c = pasic3_read_register(dev, 0x28);
    pasic3_write_register(dev, 0x28, c & 0x7f);

    dev_dbg(dev, "DS1WM OWM_EN low (active) %02x\n", c & 0x7f);
    return 0;
}

static int ds1wm_disable(struct platform_device *pdev)
{
    struct device *dev = pdev->dev.parent;
    int c;

    c = pasic3_read_register(dev, 0x28);
    pasic3_write_register(dev, 0x28, c | 0x80);

    dev_dbg(dev, "DS1WM OWM_EN high (inactive) %02x\n", c | 0x80);
    return 0;
}

static struct ds1wm_driver_data ds1wm_pdata = {
    .active_high = 0,
    .reset_recover_delay = 1,
};

static struct resource ds1wm_resources[] __initdata = {
    [0] = {
        .start  = 0,
        .flags  = IORESOURCE_MEM,
    },
    [1] = {
        .start  = 0,
        .end    = 0,
        .flags  = IORESOURCE_IRQ,
    },
};

static struct mfd_cell ds1wm_cell __initdata = {
    .name          = "ds1wm",
    .enable        = ds1wm_enable,
    .disable       = ds1wm_disable,
    .platform_data = &ds1wm_pdata,
    .pdata_size    = sizeof(ds1wm_pdata),
    .num_resources = 2,
    .resources     = ds1wm_resources,
};

static int __init pasic3_probe(struct platform_device *pdev)
{
    struct pasic3_platform_data *pdata = pdev->dev.platform_data;
    struct device *dev = &pdev->dev;
    struct pasic3_data *asic;
    struct resource *r;
    int ret;
    int irq = 0;

    r = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
    if (r) {
        ds1wm_resources[1].flags = IORESOURCE_IRQ | (r->flags &
            (IORESOURCE_IRQ_HIGHEDGE | IORESOURCE_IRQ_LOWEDGE));
        irq = r->start;
    }

    r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    if (!r)
        return -ENXIO;

    if (!request_mem_region(r->start, resource_size(r), "pasic3"))
        return -EBUSY;

    asic = kzalloc(sizeof(struct pasic3_data), GFP_KERNEL);
    if (!asic)
        return -ENOMEM;

    platform_set_drvdata(pdev, asic);

    asic->mapping = ioremap(r->start, resource_size(r));
    if (!asic->mapping) {
        dev_err(dev, "couldn't ioremap PASIC3\n");
        kfree(asic);
        return -ENOMEM;
    }

    /* calculate bus shift from mem resource */
    asic->bus_shift = (resource_size(r) - 5) >> 3;

    if (pdata && pdata->clock_rate) {
        ds1wm_pdata.clock_rate = pdata->clock_rate;
        /* the first 5 PASIC3 registers control the DS1WM */
        ds1wm_resources[0].end = (5 << asic->bus_shift) - 1;
        ret = mfd_add_devices(&pdev->dev, pdev->id,
                      &ds1wm_cell, 1, r, irq, NULL);
        if (ret < 0)
            dev_warn(dev, "failed to register DS1WM\n");
    }

    if (pdata && pdata->led_pdata) {
        led_cell.platform_data = pdata->led_pdata;
        led_cell.pdata_size = sizeof(struct pasic3_leds_machinfo);
        ret = mfd_add_devices(&pdev->dev, pdev->id, &led_cell, 1, r,
                      0, NULL);
        if (ret < 0)
            dev_warn(dev, "failed to register LED device\n");
    }

    return 0;
}

static int pasic3_remove(struct platform_device *pdev)
{
    struct pasic3_data *asic = platform_get_drvdata(pdev);
    struct resource *r;

    mfd_remove_devices(&pdev->dev);

    iounmap(asic->mapping);
    r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    release_mem_region(r->start, resource_size(r));
    kfree(asic);
    return 0;
}

MODULE_ALIAS("platform:pasic3");

static struct platform_driver pasic3_driver = {
    .driver     = {
        .name   = "pasic3",
    },
    .remove     = pasic3_remove,
};

static int __init pasic3_base_init(void)
{
    return platform_driver_probe(&pasic3_driver, pasic3_probe);
}

static void __exit pasic3_base_exit(void)
{
    platform_driver_unregister(&pasic3_driver);
}

module_init(pasic3_base_init);
module_exit(pasic3_base_exit);

MODULE_AUTHOR("Philipp Zabel <[email protected]>");
MODULE_DESCRIPTION("Core driver for HTC PASIC3");
MODULE_LICENSE("GPL");