/*
   * sdhci-dove.c Support for SDHCI on Marvell's Dove SoC
   *
   * Author: Saeed Bishara <saeed@marvell.com>
   *	   Mike Rapoport <mike@compulab.co.il>
   * Based on sdhci-cns3xxx.c
   *
   * 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.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
   */
  
  #include <linux/clk.h>
  #include <linux/err.h>
  #include <linux/gpio.h>
  #include <linux/io.h>
  #include <linux/mmc/host.h>
  #include <linux/module.h>
  #include <linux/of.h>
  #include <linux/of_gpio.h>
  
  #include "sdhci-pltfm.h"
  
  struct sdhci_dove_priv {
  	struct clk *clk;
  	int gpio_cd;
  };
  
  static irqreturn_t sdhci_dove_carddetect_irq(int irq, void *data)
  {
  	struct sdhci_host *host = data;
  
  	tasklet_schedule(&host->card_tasklet);
  	return IRQ_HANDLED;
  }
  
  static u16 sdhci_dove_readw(struct sdhci_host *host, int reg)
  {
  	u16 ret;
  
  	switch (reg) {
  	case SDHCI_HOST_VERSION:
  	case SDHCI_SLOT_INT_STATUS:
  		/* those registers don't exist */
  		return 0;
  	default:
  		ret = readw(host->ioaddr + reg);
  	}
  	return ret;
  }
  
  static u32 sdhci_dove_readl(struct sdhci_host *host, int reg)
  {
  	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
  	struct sdhci_dove_priv *priv = pltfm_host->priv;
  	u32 ret;
  
  	ret = readl(host->ioaddr + reg);
  
  	switch (reg) {
  	case SDHCI_CAPABILITIES:
  		/* Mask the support for 3.0V */
  		ret &= ~SDHCI_CAN_VDD_300;
  		break;
  	case SDHCI_PRESENT_STATE:
  		if (gpio_is_valid(priv->gpio_cd)) {
  			if (gpio_get_value(priv->gpio_cd) == 0)
  				ret |= SDHCI_CARD_PRESENT;
  			else
  				ret &= ~SDHCI_CARD_PRESENT;
  		}
  		break;
  	}
  	return ret;
  }
  
  static const struct sdhci_ops sdhci_dove_ops = {
  	.read_w	= sdhci_dove_readw,
  	.read_l	= sdhci_dove_readl,
  };
  
  static const struct sdhci_pltfm_data sdhci_dove_pdata = {
  	.ops	= &sdhci_dove_ops,
  	.quirks	= SDHCI_QUIRK_NO_SIMULT_VDD_AND_POWER |
  		  SDHCI_QUIRK_NO_BUSY_IRQ |
  		  SDHCI_QUIRK_BROKEN_TIMEOUT_VAL |
  		  SDHCI_QUIRK_FORCE_DMA |
  		  SDHCI_QUIRK_NO_HISPD_BIT,
  };
  
  static int sdhci_dove_probe(struct platform_device *pdev)
  {
  	struct sdhci_host *host;
  	struct sdhci_pltfm_host *pltfm_host;
  	struct sdhci_dove_priv *priv;
  	int ret;
  
  	priv = devm_kzalloc(&pdev->dev, sizeof(struct sdhci_dove_priv),
  			    GFP_KERNEL);
  	if (!priv) {
  		dev_err(&pdev->dev, "unable to allocate private data");
  		return -ENOMEM;
  	}
  
  	priv->clk = devm_clk_get(&pdev->dev, NULL);
  
  	if (pdev->dev.of_node) {
  		priv->gpio_cd = of_get_named_gpio(pdev->dev.of_node,
  						  "cd-gpios", 0);
  	} else {
  		priv->gpio_cd = -EINVAL;
  	}
  
  	if (gpio_is_valid(priv->gpio_cd)) {
  		ret = gpio_request(priv->gpio_cd, "sdhci-cd");
  		if (ret) {
  			dev_err(&pdev->dev, "card detect gpio request failed: %d
  ",
  				ret);
  			return ret;
  		}
  		gpio_direction_input(priv->gpio_cd);
  	}
  
  	host = sdhci_pltfm_init(pdev, &sdhci_dove_pdata, 0);
  	if (IS_ERR(host)) {
  		ret = PTR_ERR(host);
  		goto err_sdhci_pltfm_init;
  	}
  
  	pltfm_host = sdhci_priv(host);
  	pltfm_host->priv = priv;
  
  	if (!IS_ERR(priv->clk))
  		clk_prepare_enable(priv->clk);
  
  	sdhci_get_of_property(pdev);
  
  	ret = sdhci_add_host(host);
  	if (ret)
  		goto err_sdhci_add;
  
  	/*
  	 * We must request the IRQ after sdhci_add_host(), as the tasklet only
  	 * gets setup in sdhci_add_host() and we oops.
  	 */
  	if (gpio_is_valid(priv->gpio_cd)) {
  		ret = request_irq(gpio_to_irq(priv->gpio_cd),
  				  sdhci_dove_carddetect_irq,
  				  IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
  				  mmc_hostname(host->mmc), host);
  		if (ret) {
  			dev_err(&pdev->dev, "card detect irq request failed: %d
  ",
  				ret);
  			goto err_request_irq;
  		}
  	}
  
  	return 0;
  
  err_request_irq:
  	sdhci_remove_host(host, 0);
  err_sdhci_add:
  	if (!IS_ERR(priv->clk))
  		clk_disable_unprepare(priv->clk);
  	sdhci_pltfm_free(pdev);
  err_sdhci_pltfm_init:
  	if (gpio_is_valid(priv->gpio_cd))
  		gpio_free(priv->gpio_cd);
  	return ret;
  }
  
  static int sdhci_dove_remove(struct platform_device *pdev)
  {
  	struct sdhci_host *host = platform_get_drvdata(pdev);
  	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
  	struct sdhci_dove_priv *priv = pltfm_host->priv;
  
  	sdhci_pltfm_unregister(pdev);
  
  	if (gpio_is_valid(priv->gpio_cd)) {
  		free_irq(gpio_to_irq(priv->gpio_cd), host);
  		gpio_free(priv->gpio_cd);
  	}
  
  	if (!IS_ERR(priv->clk))
  		clk_disable_unprepare(priv->clk);
  
  	return 0;
  }
  
  static const struct of_device_id sdhci_dove_of_match_table[] = {
  	{ .compatible = "marvell,dove-sdhci", },
  	{}
  };
  MODULE_DEVICE_TABLE(of, sdhci_dove_of_match_table);
  
  static struct platform_driver sdhci_dove_driver = {
  	.driver		= {
  		.name	= "sdhci-dove",
  		.owner	= THIS_MODULE,
  		.pm	= SDHCI_PLTFM_PMOPS,
  		.of_match_table = of_match_ptr(sdhci_dove_of_match_table),
  	},
  	.probe		= sdhci_dove_probe,
  	.remove		= sdhci_dove_remove,
  };
  
  module_platform_driver(sdhci_dove_driver);
  
  MODULE_DESCRIPTION("SDHCI driver for Dove");
  MODULE_AUTHOR("Saeed Bishara <saeed@marvell.com>, "
  	      "Mike Rapoport <mike@compulab.co.il>");
  MODULE_LICENSE("GPL v2");