sdhci-spear.c

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/*
 * drivers/mmc/host/sdhci-spear.c
 *
 * Support of SDHCI platform devices for spear soc family
 *
 * Copyright (C) 2010 ST Microelectronics
 * Viresh Kumar <[email protected]>
 *
 * Inspired by sdhci-pltfm.c
 *
 * This file is licensed under the terms of the GNU General Public
 * License version 2. This program is licensed "as is" without any
 * warranty of any kind, whether express or implied.
 */

#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/gpio.h>
#include <linux/highmem.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/of.h>
#include <linux/of_gpio.h>
#include <linux/platform_device.h>
#include <linux/pm.h>
#include <linux/slab.h>
#include <linux/mmc/host.h>
#include <linux/mmc/sdhci-spear.h>
#include <linux/io.h>
#include "sdhci.h"

struct spear_sdhci {
    struct clk *clk;
    struct sdhci_plat_data *data;
};

/* sdhci ops */
static struct sdhci_ops sdhci_pltfm_ops = {
    /* Nothing to do for now. */
};

/* gpio card detection interrupt handler */
static irqreturn_t sdhci_gpio_irq(int irq, void *dev_id)
{
    struct platform_device *pdev = dev_id;
    struct sdhci_host *host = platform_get_drvdata(pdev);
    struct spear_sdhci *sdhci = dev_get_platdata(&pdev->dev);
    unsigned long gpio_irq_type;
    int val;

    val = gpio_get_value(sdhci->data->card_int_gpio);

    /* val == 1 -> card removed, val == 0 -> card inserted */
    /* if card removed - set irq for low level, else vice versa */
    gpio_irq_type = val ? IRQF_TRIGGER_LOW : IRQF_TRIGGER_HIGH;
    irq_set_irq_type(irq, gpio_irq_type);

    if (sdhci->data->card_power_gpio >= 0) {
        if (!sdhci->data->power_always_enb) {
            /* if card inserted, give power, otherwise remove it */
            val = sdhci->data->power_active_high ? !val : val ;
            gpio_set_value(sdhci->data->card_power_gpio, val);
        }
    }

    /* inform sdhci driver about card insertion/removal */
    tasklet_schedule(&host->card_tasklet);

    return IRQ_HANDLED;
}

#ifdef CONFIG_OF
static struct sdhci_plat_data * __devinit
sdhci_probe_config_dt(struct platform_device *pdev)
{
    struct device_node *np = pdev->dev.of_node;
    struct sdhci_plat_data *pdata = NULL;
    int cd_gpio;

    cd_gpio = of_get_named_gpio(np, "cd-gpios", 0);
    if (!gpio_is_valid(cd_gpio))
        cd_gpio = -1;

    /* If pdata is required */
    if (cd_gpio != -1) {
        pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
        if (!pdata) {
            dev_err(&pdev->dev, "DT: kzalloc failed\n");
            return ERR_PTR(-ENOMEM);
        }
    }

    pdata->card_int_gpio = cd_gpio;

    return pdata;
}
#else
static struct sdhci_plat_data * __devinit
sdhci_probe_config_dt(struct platform_device *pdev)
{
    return ERR_PTR(-ENOSYS);
}
#endif

static int __devinit sdhci_probe(struct platform_device *pdev)
{
    struct device_node *np = pdev->dev.of_node;
    struct sdhci_host *host;
    struct resource *iomem;
    struct spear_sdhci *sdhci;
    int ret;

    iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    if (!iomem) {
        ret = -ENOMEM;
        dev_dbg(&pdev->dev, "memory resource not defined\n");
        goto err;
    }

    if (!devm_request_mem_region(&pdev->dev, iomem->start,
                resource_size(iomem), "spear-sdhci")) {
        ret = -EBUSY;
        dev_dbg(&pdev->dev, "cannot request region\n");
        goto err;
    }

    sdhci = devm_kzalloc(&pdev->dev, sizeof(*sdhci), GFP_KERNEL);
    if (!sdhci) {
        ret = -ENOMEM;
        dev_dbg(&pdev->dev, "cannot allocate memory for sdhci\n");
        goto err;
    }

    /* clk enable */
    sdhci->clk = clk_get(&pdev->dev, NULL);
    if (IS_ERR(sdhci->clk)) {
        ret = PTR_ERR(sdhci->clk);
        dev_dbg(&pdev->dev, "Error getting clock\n");
        goto err;
    }

    ret = clk_prepare_enable(sdhci->clk);
    if (ret) {
        dev_dbg(&pdev->dev, "Error enabling clock\n");
        goto put_clk;
    }

    if (np) {
        sdhci->data = sdhci_probe_config_dt(pdev);
        if (IS_ERR(sdhci->data)) {
            dev_err(&pdev->dev, "DT: Failed to get pdata\n");
            return -ENODEV;
        }
    } else {
        sdhci->data = dev_get_platdata(&pdev->dev);
    }

    pdev->dev.platform_data = sdhci;

    if (pdev->dev.parent)
        host = sdhci_alloc_host(pdev->dev.parent, 0);
    else
        host = sdhci_alloc_host(&pdev->dev, 0);

    if (IS_ERR(host)) {
        ret = PTR_ERR(host);
        dev_dbg(&pdev->dev, "error allocating host\n");
        goto disable_clk;
    }

    host->hw_name = "sdhci";
    host->ops = &sdhci_pltfm_ops;
    host->irq = platform_get_irq(pdev, 0);
    host->quirks = SDHCI_QUIRK_BROKEN_ADMA;

    host->ioaddr = devm_ioremap(&pdev->dev, iomem->start,
            resource_size(iomem));
    if (!host->ioaddr) {
        ret = -ENOMEM;
        dev_dbg(&pdev->dev, "failed to remap registers\n");
        goto free_host;
    }

    ret = sdhci_add_host(host);
    if (ret) {
        dev_dbg(&pdev->dev, "error adding host\n");
        goto free_host;
    }

    platform_set_drvdata(pdev, host);

    /*
     * It is optional to use GPIOs for sdhci Power control & sdhci card
     * interrupt detection. If sdhci->data is NULL, then use original sdhci
     * lines otherwise GPIO lines.
     * If GPIO is selected for power control, then power should be disabled
     * after card removal and should be enabled when card insertion
     * interrupt occurs
     */
    if (!sdhci->data)
        return 0;

    if (sdhci->data->card_power_gpio >= 0) {
        int val = 0;

        ret = devm_gpio_request(&pdev->dev,
                sdhci->data->card_power_gpio, "sdhci");
        if (ret < 0) {
            dev_dbg(&pdev->dev, "gpio request fail: %d\n",
                    sdhci->data->card_power_gpio);
            goto set_drvdata;
        }

        if (sdhci->data->power_always_enb)
            val = sdhci->data->power_active_high;
        else
            val = !sdhci->data->power_active_high;

        ret = gpio_direction_output(sdhci->data->card_power_gpio, val);
        if (ret) {
            dev_dbg(&pdev->dev, "gpio set direction fail: %d\n",
                    sdhci->data->card_power_gpio);
            goto set_drvdata;
        }
    }

    if (sdhci->data->card_int_gpio >= 0) {
        ret = devm_gpio_request(&pdev->dev, sdhci->data->card_int_gpio,
                "sdhci");
        if (ret < 0) {
            dev_dbg(&pdev->dev, "gpio request fail: %d\n",
                    sdhci->data->card_int_gpio);
            goto set_drvdata;
        }

        ret = gpio_direction_input(sdhci->data->card_int_gpio);
        if (ret) {
            dev_dbg(&pdev->dev, "gpio set direction fail: %d\n",
                    sdhci->data->card_int_gpio);
            goto set_drvdata;
        }
        ret = devm_request_irq(&pdev->dev,
                gpio_to_irq(sdhci->data->card_int_gpio),
                sdhci_gpio_irq, IRQF_TRIGGER_LOW,
                mmc_hostname(host->mmc), pdev);
        if (ret) {
            dev_dbg(&pdev->dev, "gpio request irq fail: %d\n",
                    sdhci->data->card_int_gpio);
            goto set_drvdata;
        }

    }

    return 0;

set_drvdata:
    platform_set_drvdata(pdev, NULL);
    sdhci_remove_host(host, 1);
free_host:
    sdhci_free_host(host);
disable_clk:
    clk_disable_unprepare(sdhci->clk);
put_clk:
    clk_put(sdhci->clk);
err:
    dev_err(&pdev->dev, "spear-sdhci probe failed: %d\n", ret);
    return ret;
}

static int __devexit sdhci_remove(struct platform_device *pdev)
{
    struct sdhci_host *host = platform_get_drvdata(pdev);
    struct spear_sdhci *sdhci = dev_get_platdata(&pdev->dev);
    int dead = 0;
    u32 scratch;

    platform_set_drvdata(pdev, NULL);
    scratch = readl(host->ioaddr + SDHCI_INT_STATUS);
    if (scratch == (u32)-1)
        dead = 1;

    sdhci_remove_host(host, dead);
    sdhci_free_host(host);
    clk_disable_unprepare(sdhci->clk);
    clk_put(sdhci->clk);

    return 0;
}

#ifdef CONFIG_PM
static int sdhci_suspend(struct device *dev)
{
    struct sdhci_host *host = dev_get_drvdata(dev);
    struct spear_sdhci *sdhci = dev_get_platdata(dev);
    int ret;

    ret = sdhci_suspend_host(host);
    if (!ret)
        clk_disable_unprepare(sdhci->clk);

    return ret;
}

static int sdhci_resume(struct device *dev)
{
    struct sdhci_host *host = dev_get_drvdata(dev);
    struct spear_sdhci *sdhci = dev_get_platdata(dev);
    int ret;

    ret = clk_prepare_enable(sdhci->clk);
    if (ret) {
        dev_dbg(dev, "Resume: Error enabling clock\n");
        return ret;
    }

    return sdhci_resume_host(host);
}
#endif

static SIMPLE_DEV_PM_OPS(sdhci_pm_ops, sdhci_suspend, sdhci_resume);

#ifdef CONFIG_OF
static const struct of_device_id sdhci_spear_id_table[] = {
    { .compatible = "st,spear300-sdhci" },
    {}
};
MODULE_DEVICE_TABLE(of, sdhci_spear_id_table);
#endif

static struct platform_driver sdhci_driver = {
    .driver = {
        .name   = "sdhci",
        .owner  = THIS_MODULE,
        .pm = &sdhci_pm_ops,
        .of_match_table = of_match_ptr(sdhci_spear_id_table),
    },
    .probe      = sdhci_probe,
    .remove     = __devexit_p(sdhci_remove),
};

module_platform_driver(sdhci_driver);

MODULE_DESCRIPTION("SPEAr Secure Digital Host Controller Interface driver");
MODULE_AUTHOR("Viresh Kumar <[email protected]>");
MODULE_LICENSE("GPL v2");