text: /*
   * drivers/mmc/host/sdhci-spear.c
   *
   * Support of SDHCI platform devices for spear soc family
   *
   * Copyright (C) 2010 ST Microelectronics
   * Viresh Kumar<viresh.kumar@st.com>
   *
   * 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/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;
  }
  
  static int __devinit sdhci_probe(struct platform_device *pdev)
  {
  	struct sdhci_host *host;
  	struct resource *iomem;
  	struct spear_sdhci *sdhci;
  	int ret;
  
  	BUG_ON(pdev == NULL);
  
  	iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  	if (!iomem) {
  		ret = -ENOMEM;
  		dev_dbg(&pdev->dev, "memory resource not defined\n");
  		goto err;
  	}
  
  	if (!request_mem_region(iomem->start, resource_size(iomem),
  				"spear-sdhci")) {
  		ret = -EBUSY;
  		dev_dbg(&pdev->dev, "cannot request region\n");
  		goto err;
  	}
  
  	sdhci = kzalloc(sizeof(*sdhci), GFP_KERNEL);
  	if (!sdhci) {
  		ret = -ENOMEM;
  		dev_dbg(&pdev->dev, "cannot allocate memory for sdhci\n");
  		goto err_kzalloc;
  	}
  
  	/* 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_clk_get;
  	}
  
  	ret = clk_enable(sdhci->clk);
  	if (ret) {
  		dev_dbg(&pdev->dev, "Error enabling clock\n");
  		goto err_clk_enb;
  	}
  
  	/* overwrite platform_data */
  	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 err_alloc_host;
  	}
  
  	host->hw_name = "sdhci";
  	host->ops = &sdhci_pltfm_ops;
  	host->irq = platform_get_irq(pdev, 0);
  	host->quirks = SDHCI_QUIRK_BROKEN_ADMA;
  
  	host->ioaddr = ioremap(iomem->start, resource_size(iomem));
  	if (!host->ioaddr) {
  		ret = -ENOMEM;
  		dev_dbg(&pdev->dev, "failed to remap registers\n");
  		goto err_ioremap;
  	}
  
  	ret = sdhci_add_host(host);
  	if (ret) {
  		dev_dbg(&pdev->dev, "error adding host\n");
  		goto err_add_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 = gpio_request(sdhci->data->card_power_gpio, "sdhci");
  		if (ret < 0) {
  			dev_dbg(&pdev->dev, "gpio request fail: %d\n",
  					sdhci->data->card_power_gpio);
  			goto err_pgpio_request;
  		}
  
  		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 err_pgpio_direction;
  		}
  	}
  
  	if (sdhci->data->card_int_gpio >= 0) {
  		ret = gpio_request(sdhci->data->card_int_gpio, "sdhci");
  		if (ret < 0) {
  			dev_dbg(&pdev->dev, "gpio request fail: %d\n",
  					sdhci->data->card_int_gpio);
  			goto err_igpio_request;
  		}
  
  		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 err_igpio_direction;
  		}
  		ret = request_irq(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 err_igpio_request_irq;
  		}
  
  	}
  
  	return 0;
  
  err_igpio_request_irq:
  err_igpio_direction:
  	if (sdhci->data->card_int_gpio >= 0)
  		gpio_free(sdhci->data->card_int_gpio);
  err_igpio_request:
  err_pgpio_direction:
  	if (sdhci->data->card_power_gpio >= 0)
  		gpio_free(sdhci->data->card_power_gpio);
  err_pgpio_request:
  	platform_set_drvdata(pdev, NULL);
  	sdhci_remove_host(host, 1);
  err_add_host:
  	iounmap(host->ioaddr);
  err_ioremap:
  	sdhci_free_host(host);
  err_alloc_host:
  	clk_disable(sdhci->clk);
  err_clk_enb:
  	clk_put(sdhci->clk);
  err_clk_get:
  	kfree(sdhci);
  err_kzalloc:
  	release_mem_region(iomem->start, resource_size(iomem));
  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 resource *iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  	struct spear_sdhci *sdhci = dev_get_platdata(&pdev->dev);
  	int dead;
  	u32 scratch;
  
  	if (sdhci->data) {
  		if (sdhci->data->card_int_gpio >= 0) {
  			free_irq(gpio_to_irq(sdhci->data->card_int_gpio), pdev);
  			gpio_free(sdhci->data->card_int_gpio);
  		}
  
  		if (sdhci->data->card_power_gpio >= 0)
  			gpio_free(sdhci->data->card_power_gpio);
  	}
  
  	platform_set_drvdata(pdev, NULL);
  	dead = 0;
  	scratch = readl(host->ioaddr + SDHCI_INT_STATUS);
  	if (scratch == (u32)-1)
  		dead = 1;
  
  	sdhci_remove_host(host, dead);
  	iounmap(host->ioaddr);
  	sdhci_free_host(host);
  	clk_disable(sdhci->clk);
  	clk_put(sdhci->clk);
  	kfree(sdhci);
  	if (iomem)
  		release_mem_region(iomem->start, resource_size(iomem));
  
  	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(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_enable(sdhci->clk);
  	if (ret) {
  		dev_dbg(dev, "Resume: Error enabling clock\n");
  		return ret;
  	}
  
  	return sdhci_resume_host(host);
  }
  
  const struct dev_pm_ops sdhci_pm_ops = {
  	.suspend	= sdhci_suspend,
  	.resume		= sdhci_resume,
  };
  #endif
  
  static struct platform_driver sdhci_driver = {
  	.driver = {
  		.name	= "sdhci",
  		.owner	= THIS_MODULE,
  #ifdef CONFIG_PM
  		.pm	= &sdhci_pm_ops,
  #endif
  	},
  	.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 <viresh.kumar@st.com>");
  MODULE_LICENSE("GPL v2");
  