scoop.c

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/*
 * Support code for the SCOOP interface found on various Sharp PDAs
 *
 * Copyright (c) 2004 Richard Purdie
 *
 *  Based on code written by Sharp/Lineo for 2.4 kernels
 *
 * 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/device.h>
#include <linux/gpio.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
#include <linux/export.h>
#include <linux/io.h>
#include <asm/hardware/scoop.h>

/* PCMCIA to Scoop linkage

   There is no easy way to link multiple scoop devices into one
   single entity for the pxa2xx_pcmcia device so this structure
   is used which is setup by the platform code.

   This file is never modular so this symbol is always
   accessile to the board support files.
*/
struct scoop_pcmcia_config *platform_scoop_config;
EXPORT_SYMBOL(platform_scoop_config);

struct  scoop_dev {
    void __iomem *base;
    struct gpio_chip gpio;
    spinlock_t scoop_lock;
    unsigned short suspend_clr;
    unsigned short suspend_set;
    u32 scoop_gpwr;
};

void reset_scoop(struct device *dev)
{
    struct scoop_dev *sdev = dev_get_drvdata(dev);

    iowrite16(0x0100, sdev->base + SCOOP_MCR);  /* 00 */
    iowrite16(0x0000, sdev->base + SCOOP_CDR);  /* 04 */
    iowrite16(0x0000, sdev->base + SCOOP_CCR);  /* 10 */
    iowrite16(0x0000, sdev->base + SCOOP_IMR);  /* 18 */
    iowrite16(0x00FF, sdev->base + SCOOP_IRM);  /* 14 */
    iowrite16(0x0000, sdev->base + SCOOP_ISR);  /* 1C */
    iowrite16(0x0000, sdev->base + SCOOP_IRM);
}

static void __scoop_gpio_set(struct scoop_dev *sdev,
            unsigned offset, int value)
{
    unsigned short gpwr;

    gpwr = ioread16(sdev->base + SCOOP_GPWR);
    if (value)
        gpwr |= 1 << (offset + 1);
    else
        gpwr &= ~(1 << (offset + 1));
    iowrite16(gpwr, sdev->base + SCOOP_GPWR);
}

static void scoop_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
{
    struct scoop_dev *sdev = container_of(chip, struct scoop_dev, gpio);
    unsigned long flags;

    spin_lock_irqsave(&sdev->scoop_lock, flags);

    __scoop_gpio_set(sdev, offset, value);

    spin_unlock_irqrestore(&sdev->scoop_lock, flags);
}

static int scoop_gpio_get(struct gpio_chip *chip, unsigned offset)
{
    struct scoop_dev *sdev = container_of(chip, struct scoop_dev, gpio);

    /* XXX: I'm unsure, but it seems so */
    return ioread16(sdev->base + SCOOP_GPRR) & (1 << (offset + 1));
}

static int scoop_gpio_direction_input(struct gpio_chip *chip,
            unsigned offset)
{
    struct scoop_dev *sdev = container_of(chip, struct scoop_dev, gpio);
    unsigned long flags;
    unsigned short gpcr;

    spin_lock_irqsave(&sdev->scoop_lock, flags);

    gpcr = ioread16(sdev->base + SCOOP_GPCR);
    gpcr &= ~(1 << (offset + 1));
    iowrite16(gpcr, sdev->base + SCOOP_GPCR);

    spin_unlock_irqrestore(&sdev->scoop_lock, flags);

    return 0;
}

static int scoop_gpio_direction_output(struct gpio_chip *chip,
            unsigned offset, int value)
{
    struct scoop_dev *sdev = container_of(chip, struct scoop_dev, gpio);
    unsigned long flags;
    unsigned short gpcr;

    spin_lock_irqsave(&sdev->scoop_lock, flags);

    __scoop_gpio_set(sdev, offset, value);

    gpcr = ioread16(sdev->base + SCOOP_GPCR);
    gpcr |= 1 << (offset + 1);
    iowrite16(gpcr, sdev->base + SCOOP_GPCR);

    spin_unlock_irqrestore(&sdev->scoop_lock, flags);

    return 0;
}

unsigned short read_scoop_reg(struct device *dev, unsigned short reg)
{
    struct scoop_dev *sdev = dev_get_drvdata(dev);
    return ioread16(sdev->base + reg);
}

void write_scoop_reg(struct device *dev, unsigned short reg, unsigned short data)
{
    struct scoop_dev *sdev = dev_get_drvdata(dev);
    iowrite16(data, sdev->base + reg);
}

EXPORT_SYMBOL(reset_scoop);
EXPORT_SYMBOL(read_scoop_reg);
EXPORT_SYMBOL(write_scoop_reg);

#ifdef CONFIG_PM
static void check_scoop_reg(struct scoop_dev *sdev)
{
    unsigned short mcr;

    mcr = ioread16(sdev->base + SCOOP_MCR);
    if ((mcr & 0x100) == 0)
        iowrite16(0x0101, sdev->base + SCOOP_MCR);
}

static int scoop_suspend(struct platform_device *dev, pm_message_t state)
{
    struct scoop_dev *sdev = platform_get_drvdata(dev);

    check_scoop_reg(sdev);
    sdev->scoop_gpwr = ioread16(sdev->base + SCOOP_GPWR);
    iowrite16((sdev->scoop_gpwr & ~sdev->suspend_clr) | sdev->suspend_set, sdev->base + SCOOP_GPWR);

    return 0;
}

static int scoop_resume(struct platform_device *dev)
{
    struct scoop_dev *sdev = platform_get_drvdata(dev);

    check_scoop_reg(sdev);
    iowrite16(sdev->scoop_gpwr, sdev->base + SCOOP_GPWR);

    return 0;
}
#else
#define scoop_suspend   NULL
#define scoop_resume    NULL
#endif

static int __devinit scoop_probe(struct platform_device *pdev)
{
    struct scoop_dev *devptr;
    struct scoop_config *inf;
    struct resource *mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    int ret;
    int temp;

    if (!mem)
        return -EINVAL;

    devptr = kzalloc(sizeof(struct scoop_dev), GFP_KERNEL);
    if (!devptr)
        return -ENOMEM;

    spin_lock_init(&devptr->scoop_lock);

    inf = pdev->dev.platform_data;
    devptr->base = ioremap(mem->start, resource_size(mem));

    if (!devptr->base) {
        ret = -ENOMEM;
        goto err_ioremap;
    }

    platform_set_drvdata(pdev, devptr);

    printk("Sharp Scoop Device found at 0x%08x -> 0x%8p\n",(unsigned int)mem->start, devptr->base);

    iowrite16(0x0140, devptr->base + SCOOP_MCR);
    reset_scoop(&pdev->dev);
    iowrite16(0x0000, devptr->base + SCOOP_CPR);
    iowrite16(inf->io_dir & 0xffff, devptr->base + SCOOP_GPCR);
    iowrite16(inf->io_out & 0xffff, devptr->base + SCOOP_GPWR);

    devptr->suspend_clr = inf->suspend_clr;
    devptr->suspend_set = inf->suspend_set;

    devptr->gpio.base = -1;

    if (inf->gpio_base != 0) {
        devptr->gpio.label = dev_name(&pdev->dev);
        devptr->gpio.base = inf->gpio_base;
        devptr->gpio.ngpio = 12; /* PA11 = 0, PA12 = 1, etc. up to PA22 = 11 */
        devptr->gpio.set = scoop_gpio_set;
        devptr->gpio.get = scoop_gpio_get;
        devptr->gpio.direction_input = scoop_gpio_direction_input;
        devptr->gpio.direction_output = scoop_gpio_direction_output;

        ret = gpiochip_add(&devptr->gpio);
        if (ret)
            goto err_gpio;
    }

    return 0;

    if (devptr->gpio.base != -1)
        temp = gpiochip_remove(&devptr->gpio);
err_gpio:
    platform_set_drvdata(pdev, NULL);
err_ioremap:
    iounmap(devptr->base);
    kfree(devptr);

    return ret;
}

static int __devexit scoop_remove(struct platform_device *pdev)
{
    struct scoop_dev *sdev = platform_get_drvdata(pdev);
    int ret;

    if (!sdev)
        return -EINVAL;

    if (sdev->gpio.base != -1) {
        ret = gpiochip_remove(&sdev->gpio);
        if (ret) {
            dev_err(&pdev->dev, "Can't remove gpio chip: %d\n", ret);
            return ret;
        }
    }

    platform_set_drvdata(pdev, NULL);
    iounmap(sdev->base);
    kfree(sdev);

    return 0;
}

static struct platform_driver scoop_driver = {
    .probe      = scoop_probe,
    .remove     = __devexit_p(scoop_remove),
    .suspend    = scoop_suspend,
    .resume     = scoop_resume,
    .driver     = {
        .name   = "sharp-scoop",
    },
};

static int __init scoop_init(void)
{
    return platform_driver_register(&scoop_driver);
}

subsys_initcall(scoop_init);