/*
   * drivers/mmc/host/sdhci-spear.c
   *
   * Support of SDHCI platform devices for spear soc family
   *
   * Copyright (C) 2010 ST Microelectronics

   * Viresh Kumar <vireshk@kernel.org>

   *
   * 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/slot-gpio.h>

  #include <linux/io.h>
  #include "sdhci.h"
  
  struct spear_sdhci {
  	struct clk *clk;

  	int card_int_gpio;

  };
  
  /* sdhci ops */

  static const struct sdhci_ops sdhci_pltfm_ops = {

  	.set_clock = sdhci_set_clock,

  	.set_bus_width = sdhci_set_bus_width,

  	.reset = sdhci_reset,

  	.set_uhs_signaling = sdhci_set_uhs_signaling,

  };

  static void sdhci_probe_config_dt(struct device_node *np,
  				struct spear_sdhci *host)

  {

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

  	host->card_int_gpio = cd_gpio;

  }

  static int sdhci_probe(struct platform_device *pdev)

  {
  	struct sdhci_host *host;
  	struct resource *iomem;
  	struct spear_sdhci *sdhci;

  	struct device *dev;

  	int ret;

  	dev = pdev->dev.parent ? pdev->dev.parent : &pdev->dev;
  	host = sdhci_alloc_host(dev, sizeof(*sdhci));
  	if (IS_ERR(host)) {
  		ret = PTR_ERR(host);

  		dev_dbg(&pdev->dev, "cannot allocate memory for sdhci
  ");

  		goto err;

  	}

  	iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  	host->ioaddr = devm_ioremap_resource(&pdev->dev, iomem);
  	if (IS_ERR(host->ioaddr)) {
  		ret = PTR_ERR(host->ioaddr);
  		dev_dbg(&pdev->dev, "unable to map iomem: %d
  ", ret);
  		goto err_host;
  	}
  
  	host->hw_name = "sdhci";
  	host->ops = &sdhci_pltfm_ops;
  	host->irq = platform_get_irq(pdev, 0);
  	host->quirks = SDHCI_QUIRK_BROKEN_ADMA;

  	sdhci = sdhci_priv(host);

  	/* clk enable */

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

  	if (IS_ERR(sdhci->clk)) {
  		ret = PTR_ERR(sdhci->clk);
  		dev_dbg(&pdev->dev, "Error getting clock
  ");

  		goto err_host;

  	}

  	ret = clk_prepare_enable(sdhci->clk);

  	if (ret) {
  		dev_dbg(&pdev->dev, "Error enabling clock
  ");

  		goto err_host;

  	}

  	ret = clk_set_rate(sdhci->clk, 50000000);
  	if (ret)
  		dev_dbg(&pdev->dev, "Error setting desired clk, clk=%lu
  ",
  				clk_get_rate(sdhci->clk));

  	sdhci_probe_config_dt(pdev->dev.of_node, sdhci);

  	/*
  	 * It is optional to use GPIOs for sdhci card detection. If

  	 * sdhci->card_int_gpio < 0, then use original sdhci lines otherwise

  	 * GPIO lines. We use the built-in GPIO support for this.
  	 */

  	if (sdhci->card_int_gpio >= 0) {
  		ret = mmc_gpio_request_cd(host->mmc, sdhci->card_int_gpio, 0);

  		if (ret < 0) {
  			dev_dbg(&pdev->dev,
  				"failed to request card-detect gpio%d
  ",

  				sdhci->card_int_gpio);

  			goto disable_clk;
  		}
  	}

  	ret = sdhci_add_host(host);
  	if (ret) {
  		dev_dbg(&pdev->dev, "error adding host
  ");

  		goto disable_clk;

  	}
  
  	platform_set_drvdata(pdev, host);

  	return 0;

  disable_clk:

  	clk_disable_unprepare(sdhci->clk);

  err_host:
  	sdhci_free_host(host);

  err:
  	dev_err(&pdev->dev, "spear-sdhci probe failed: %d
  ", ret);
  	return ret;
  }

  static int sdhci_remove(struct platform_device *pdev)

  {
  	struct sdhci_host *host = platform_get_drvdata(pdev);

  	struct spear_sdhci *sdhci = sdhci_priv(host);

  	int dead = 0;

  	u32 scratch;

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

  	clk_disable_unprepare(sdhci->clk);

  	sdhci_free_host(host);

  
  	return 0;
  }

  #ifdef CONFIG_PM_SLEEP

  static int sdhci_suspend(struct device *dev)
  {
  	struct sdhci_host *host = dev_get_drvdata(dev);

  	struct spear_sdhci *sdhci = sdhci_priv(host);

  	int ret;

  	ret = sdhci_suspend_host(host);

  	if (!ret)

  		clk_disable(sdhci->clk);

  
  	return ret;
  }
  
  static int sdhci_resume(struct device *dev)
  {
  	struct sdhci_host *host = dev_get_drvdata(dev);

  	struct spear_sdhci *sdhci = sdhci_priv(host);

  	int ret;

  	ret = clk_enable(sdhci->clk);

  	if (ret) {
  		dev_dbg(dev, "Resume: Error enabling clock
  ");
  		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",

  		.pm	= &sdhci_pm_ops,

  		.of_match_table = of_match_ptr(sdhci_spear_id_table),

  	},
  	.probe		= sdhci_probe,

  	.remove		= sdhci_remove,

  };

  module_platform_driver(sdhci_driver);

  
  MODULE_DESCRIPTION("SPEAr Secure Digital Host Controller Interface driver");

  MODULE_AUTHOR("Viresh Kumar <vireshk@kernel.org>");

  MODULE_LICENSE("GPL v2");