mmc: mvsdio: implement a Device Tree binding

* Marvell orion-sdio controller

This file documents differences between the core properties in mmc.txt

and the properties used by the orion-sdio driver.

- compatible: Should be "marvell,orion-sdio"

- clocks: reference to the clock of the SDIO interface

Example:

	mvsdio@d00d4000 {

		compatible = "marvell,orion-sdio";

		reg = <0xd00d4000 0x200>;

		interrupts = <54>;

		clocks = <&gateclk 17>;

		status = "disabled";

	};

#include <linux/irq.h>

#include <linux/clk.h>

#include <linux/gpio.h>

#include <linux/of_gpio.h>

#include <linux/of_irq.h>

#include <linux/mmc/host.h>

#include <linux/mmc/slot-gpio.h>

static int __init mvsd_probe(struct platform_device *pdev)

{

	struct device_node *np = pdev->dev.of_node;

	struct mmc_host *mmc = NULL;

	struct mvsd_host *host = NULL;

	const struct mvsdio_platform_data *mvsd_data;

	const struct mbus_dram_target_info *dram;

	struct resource *r;

	int ret, irq;

	int gpio_card_detect, gpio_write_protect;

	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);

	irq = platform_get_irq(pdev, 0);

	mvsd_data = pdev->dev.platform_data;

	if (!r || irq < 0 || !mvsd_data)

	if (!r || irq < 0)

		return -ENXIO;

	mmc = mmc_alloc_host(sizeof(struct mvsd_host), &pdev->dev);

	host = mmc_priv(mmc);

	host->mmc = mmc;

	host->dev = &pdev->dev;

	/*

	 * Some non-DT platforms do not pass a clock, and the clock

	 * frequency is passed through platform_data. On DT platforms,

	 * a clock must always be passed, even if there is no gatable

	 * clock associated to the SDIO interface (it can simply be a

	 * fixed rate clock).

	 */

	host->clk = devm_clk_get(&pdev->dev, NULL);

	if (!IS_ERR(host->clk))

		clk_prepare_enable(host->clk);

	if (np) {

		if (IS_ERR(host->clk)) {

			dev_err(&pdev->dev, "DT platforms must have a clock associated\n");

			ret = -EINVAL;

			goto out;

		}

		host->base_clock = clk_get_rate(host->clk) / 2;

		gpio_card_detect = of_get_named_gpio(np, "cd-gpios", 0);

		gpio_write_protect = of_get_named_gpio(np, "wp-gpios", 0);

	} else {

		const struct mvsdio_platform_data *mvsd_data;

		mvsd_data = pdev->dev.platform_data;

		if (!mvsd_data) {

			ret = -ENXIO;

			goto out;

		}

		host->base_clock = mvsd_data->clock / 2;

	host->clk = ERR_PTR(-EINVAL);

		gpio_card_detect = mvsd_data->gpio_card_detect;

		gpio_write_protect = mvsd_data->gpio_write_protect;

	}

	mmc->ops = &mvsd_ops;

		goto out;

	}

	/* Not all platforms can gate the clock, so it is not

	   an error if the clock does not exists. */

	host->clk = devm_clk_get(&pdev->dev, NULL);

	if (!IS_ERR(host->clk))

		clk_prepare_enable(host->clk);

	if (gpio_is_valid(mvsd_data->gpio_card_detect)) {

		ret = mmc_gpio_request_cd(mmc, mvsd_data->gpio_card_detect);

	if (gpio_is_valid(gpio_card_detect)) {

		ret = mmc_gpio_request_cd(mmc, gpio_card_detect);

		if (ret)

			goto out;

	} else

		mmc->caps |= MMC_CAP_NEEDS_POLL;

	mmc_gpio_request_ro(mmc, mvsd_data->gpio_write_protect);

	mmc_gpio_request_ro(mmc, gpio_write_protect);

	setup_timer(&host->timer, mvsd_timeout_timer, (unsigned long)host);

	platform_set_drvdata(pdev, mmc);

			   mmc_hostname(mmc), DRIVER_NAME);

	if (!(mmc->caps & MMC_CAP_NEEDS_POLL))

		printk("using GPIO %d for card detection\n",

		       mvsd_data->gpio_card_detect);

		       gpio_card_detect);

	else

		printk("lacking card detect (fall back to polling)\n");

	return 0;

#define mvsd_resume	NULL

#endif

static const struct of_device_id mvsdio_dt_ids[] = {

	{ .compatible = "marvell,orion-sdio" },

	{ /* sentinel */ }

};

MODULE_DEVICE_TABLE(of, mvsdio_dt_ids);

static struct platform_driver mvsd_driver = {

	.remove		= __exit_p(mvsd_remove),

	.suspend	= mvsd_suspend,

	.resume		= mvsd_resume,

	.driver		= {

		.name	= DRIVER_NAME,

		.of_match_table = mvsdio_dt_ids,

	},

};