sdhci-of-arasan.c

/*
 * Arasan Secure Digital Host Controller Interface.
 * Copyright (C) 2011 - 2012 Michal Simek <monstr@monstr.eu>
 * Copyright (c) 2012 Wind River Systems, Inc.
 * Copyright (C) 2013 Pengutronix e.K.
 * Copyright (C) 2013 Xilinx Inc.
 *
 * Based on sdhci-of-esdhc.c
 *
 * Copyright (c) 2007 Freescale Semiconductor, Inc.
 * Copyright (c) 2009 MontaVista Software, Inc.
 *
 * Authors: Xiaobo Xie <X.Xie@freescale.com>
 *	    Anton Vorontsov <avorontsov@ru.mvista.com>
 *
 * 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; either version 2 of the License, or (at
 * your option) any later version.
 */

#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/phy/phy.h>
#include "sdhci-pltfm.h"

#define SDHCI_ARASAN_CLK_CTRL_OFFSET	0x2c
#define SDHCI_ARASAN_VENDOR_REGISTER	0x78

#define VENDOR_ENHANCED_STROBE		BIT(0)
#define CLK_CTRL_TIMEOUT_SHIFT		16
#define CLK_CTRL_TIMEOUT_MASK		(0xf << CLK_CTRL_TIMEOUT_SHIFT)
#define CLK_CTRL_TIMEOUT_MIN_EXP	13

/**
 * struct sdhci_arasan_data
 * @clk_ahb:	Pointer to the AHB clock
 * @phy:	Pointer to the generic phy
 * @phy_on:	True if the PHY is turned on.
 */
struct sdhci_arasan_data {
	struct clk	*clk_ahb;
	struct phy	*phy;
	bool		phy_on;
};

static unsigned int sdhci_arasan_get_timeout_clock(struct sdhci_host *host)
{
	u32 div;
	unsigned long freq;
	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);

	div = readl(host->ioaddr + SDHCI_ARASAN_CLK_CTRL_OFFSET);
	div = (div & CLK_CTRL_TIMEOUT_MASK) >> CLK_CTRL_TIMEOUT_SHIFT;

	freq = clk_get_rate(pltfm_host->clk);
	freq /= 1 << (CLK_CTRL_TIMEOUT_MIN_EXP + div);

	return freq;
}

static void sdhci_arasan_set_clock(struct sdhci_host *host, unsigned int clock)
{
	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
	struct sdhci_arasan_data *sdhci_arasan = sdhci_pltfm_priv(pltfm_host);

	if (sdhci_arasan->phy_on && !IS_ERR(sdhci_arasan->phy)) {
		sdhci_arasan->phy_on = false;

		spin_unlock_irq(&host->lock);
		phy_power_off(sdhci_arasan->phy);
		spin_lock_irq(&host->lock);
	}

	sdhci_set_clock(host, clock);

	if (host->mmc->actual_clock && !IS_ERR(sdhci_arasan->phy)) {
		sdhci_arasan->phy_on = true;

		spin_unlock_irq(&host->lock);
		phy_power_on(sdhci_arasan->phy);
		spin_lock_irq(&host->lock);
	}
}

static void sdhci_arasan_hs400_enhanced_strobe(struct mmc_host *mmc,
					struct mmc_ios *ios)
{
	u32 vendor;
	struct sdhci_host *host = mmc_priv(mmc);

	vendor = readl(host->ioaddr + SDHCI_ARASAN_VENDOR_REGISTER);
	if (ios->enhanced_strobe)
		vendor |= VENDOR_ENHANCED_STROBE;
	else
		vendor &= ~VENDOR_ENHANCED_STROBE;

	writel(vendor, host->ioaddr + SDHCI_ARASAN_VENDOR_REGISTER);
}

static struct sdhci_ops sdhci_arasan_ops = {
	.set_clock = sdhci_arasan_set_clock,
	.get_max_clock = sdhci_pltfm_clk_get_max_clock,
	.get_timeout_clock = sdhci_arasan_get_timeout_clock,
	.set_bus_width = sdhci_set_bus_width,
	.reset = sdhci_reset,
	.set_uhs_signaling = sdhci_set_uhs_signaling,
};

static struct sdhci_pltfm_data sdhci_arasan_pdata = {
	.ops = &sdhci_arasan_ops,
	.quirks = SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN,
	.quirks2 = SDHCI_QUIRK2_PRESET_VALUE_BROKEN |
			SDHCI_QUIRK2_CLOCK_DIV_ZERO_BROKEN,
};

#ifdef CONFIG_PM_SLEEP
/**
 * sdhci_arasan_suspend - Suspend method for the driver
 * @dev:	Address of the device structure
 * Returns 0 on success and error value on error
 *
 * Put the device in a low power state.
 */
static int sdhci_arasan_suspend(struct device *dev)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct sdhci_host *host = platform_get_drvdata(pdev);
	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
	struct sdhci_arasan_data *sdhci_arasan = sdhci_pltfm_priv(pltfm_host);
	int ret;

	ret = sdhci_suspend_host(host);
	if (ret)
		return ret;

	if (!IS_ERR(sdhci_arasan->phy)) {
		ret = phy_power_off(sdhci_arasan->phy);
		if (ret) {
			dev_err(dev, "Cannot power off phy.\n");
			sdhci_resume_host(host);
			return ret;
		}
	}

	clk_disable(pltfm_host->clk);
	clk_disable(sdhci_arasan->clk_ahb);

	return 0;
}

/**
 * sdhci_arasan_resume - Resume method for the driver
 * @dev:	Address of the device structure
 * Returns 0 on success and error value on error
 *
 * Resume operation after suspend
 */
static int sdhci_arasan_resume(struct device *dev)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct sdhci_host *host = platform_get_drvdata(pdev);
	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
	struct sdhci_arasan_data *sdhci_arasan = sdhci_pltfm_priv(pltfm_host);
	int ret;

	ret = clk_enable(sdhci_arasan->clk_ahb);
	if (ret) {
		dev_err(dev, "Cannot enable AHB clock.\n");
		return ret;
	}

	ret = clk_enable(pltfm_host->clk);
	if (ret) {
		dev_err(dev, "Cannot enable SD clock.\n");
		return ret;
	}

	if (!IS_ERR(sdhci_arasan->phy)) {
		ret = phy_power_on(sdhci_arasan->phy);
		if (ret) {
			dev_err(dev, "Cannot power on phy.\n");
			return ret;
		}
	}

	return sdhci_resume_host(host);
}
#endif /* ! CONFIG_PM_SLEEP */

static SIMPLE_DEV_PM_OPS(sdhci_arasan_dev_pm_ops, sdhci_arasan_suspend,
			 sdhci_arasan_resume);

static int sdhci_arasan_probe(struct platform_device *pdev)
{
	int ret;
	struct clk *clk_xin;
	struct sdhci_host *host;
	struct sdhci_pltfm_host *pltfm_host;
	struct sdhci_arasan_data *sdhci_arasan;

	host = sdhci_pltfm_init(pdev, &sdhci_arasan_pdata,
				sizeof(*sdhci_arasan));
	if (IS_ERR(host))
		return PTR_ERR(host);

	pltfm_host = sdhci_priv(host);
	sdhci_arasan = sdhci_pltfm_priv(pltfm_host);

	sdhci_arasan->clk_ahb = devm_clk_get(&pdev->dev, "clk_ahb");
	if (IS_ERR(sdhci_arasan->clk_ahb)) {
		dev_err(&pdev->dev, "clk_ahb clock not found.\n");
		ret = PTR_ERR(sdhci_arasan->clk_ahb);
		goto err_pltfm_free;
	}

	clk_xin = devm_clk_get(&pdev->dev, "clk_xin");
	if (IS_ERR(clk_xin)) {
		dev_err(&pdev->dev, "clk_xin clock not found.\n");
		ret = PTR_ERR(clk_xin);
		goto err_pltfm_free;
	}

	ret = clk_prepare_enable(sdhci_arasan->clk_ahb);
	if (ret) {
		dev_err(&pdev->dev, "Unable to enable AHB clock.\n");
		goto err_pltfm_free;
	}

	ret = clk_prepare_enable(clk_xin);
	if (ret) {
		dev_err(&pdev->dev, "Unable to enable SD clock.\n");
		goto clk_dis_ahb;
	}

	sdhci_get_of_property(pdev);
	pltfm_host->clk = clk_xin;

	ret = mmc_of_parse(host->mmc);
	if (ret) {
		dev_err(&pdev->dev, "parsing dt failed (%u)\n", ret);
		goto clk_disable_all;
	}

	sdhci_arasan->phy = ERR_PTR(-ENODEV);
	if (of_device_is_compatible(pdev->dev.of_node,
				    "arasan,sdhci-5.1")) {
		sdhci_arasan->phy = devm_phy_get(&pdev->dev,
						 "phy_arasan");
		if (IS_ERR(sdhci_arasan->phy)) {
			ret = PTR_ERR(sdhci_arasan->phy);
			dev_err(&pdev->dev, "No phy for arasan,sdhci-5.1.\n");
			goto clk_disable_all;
		}

		ret = phy_init(sdhci_arasan->phy);
		if (ret < 0) {
			dev_err(&pdev->dev, "phy_init err.\n");
			goto clk_disable_all;
		}

		host->mmc_host_ops.hs400_enhanced_strobe =
					sdhci_arasan_hs400_enhanced_strobe;
	}

	ret = sdhci_add_host(host);
	if (ret)
		goto err_add_host;

	return 0;

err_add_host:
	if (!IS_ERR(sdhci_arasan->phy))
		phy_exit(sdhci_arasan->phy);
clk_disable_all:
	clk_disable_unprepare(clk_xin);
clk_dis_ahb:
	clk_disable_unprepare(sdhci_arasan->clk_ahb);
err_pltfm_free:
	sdhci_pltfm_free(pdev);
	return ret;
}

static int sdhci_arasan_remove(struct platform_device *pdev)
{
	int ret;
	struct sdhci_host *host = platform_get_drvdata(pdev);
	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
	struct sdhci_arasan_data *sdhci_arasan = sdhci_pltfm_priv(pltfm_host);
	struct clk *clk_ahb = sdhci_arasan->clk_ahb;

	if (!IS_ERR(sdhci_arasan->phy)) {
		phy_power_off(sdhci_arasan->phy);
		phy_exit(sdhci_arasan->phy);
	}

	ret = sdhci_pltfm_unregister(pdev);

	clk_disable_unprepare(clk_ahb);

	return ret;
}

static const struct of_device_id sdhci_arasan_of_match[] = {
	{ .compatible = "arasan,sdhci-8.9a" },
	{ .compatible = "arasan,sdhci-5.1" },
	{ .compatible = "arasan,sdhci-4.9a" },
	{ }
};
MODULE_DEVICE_TABLE(of, sdhci_arasan_of_match);

static struct platform_driver sdhci_arasan_driver = {
	.driver = {
		.name = "sdhci-arasan",
		.of_match_table = sdhci_arasan_of_match,
		.pm = &sdhci_arasan_dev_pm_ops,
	},
	.probe = sdhci_arasan_probe,
	.remove = sdhci_arasan_remove,
};

module_platform_driver(sdhci_arasan_driver);

MODULE_DESCRIPTION("Driver for the Arasan SDHCI Controller");
MODULE_AUTHOR("Soeren Brinkmann <soren.brinkmann@xilinx.com>");
MODULE_LICENSE("GPL");