linux/drivers/mmc/host/sdhci-spear.c
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   1/*
   2 * drivers/mmc/host/sdhci-spear.c
   3 *
   4 * Support of SDHCI platform devices for spear soc family
   5 *
   6 * Copyright (C) 2010 ST Microelectronics
   7 * Viresh Kumar <vireshk@kernel.org>
   8 *
   9 * Inspired by sdhci-pltfm.c
  10 *
  11 * This file is licensed under the terms of the GNU General Public
  12 * License version 2. This program is licensed "as is" without any
  13 * warranty of any kind, whether express or implied.
  14 */
  15
  16#include <linux/clk.h>
  17#include <linux/delay.h>
  18#include <linux/gpio.h>
  19#include <linux/highmem.h>
  20#include <linux/module.h>
  21#include <linux/interrupt.h>
  22#include <linux/irq.h>
  23#include <linux/of.h>
  24#include <linux/of_gpio.h>
  25#include <linux/platform_device.h>
  26#include <linux/pm.h>
  27#include <linux/slab.h>
  28#include <linux/mmc/host.h>
  29#include <linux/mmc/slot-gpio.h>
  30#include <linux/io.h>
  31#include "sdhci.h"
  32
  33struct spear_sdhci {
  34        struct clk *clk;
  35        int card_int_gpio;
  36};
  37
  38/* sdhci ops */
  39static const struct sdhci_ops sdhci_pltfm_ops = {
  40        .set_clock = sdhci_set_clock,
  41        .set_bus_width = sdhci_set_bus_width,
  42        .reset = sdhci_reset,
  43        .set_uhs_signaling = sdhci_set_uhs_signaling,
  44};
  45
  46static void sdhci_probe_config_dt(struct device_node *np,
  47                                struct spear_sdhci *host)
  48{
  49        int cd_gpio;
  50
  51        cd_gpio = of_get_named_gpio(np, "cd-gpios", 0);
  52        if (!gpio_is_valid(cd_gpio))
  53                cd_gpio = -1;
  54
  55        host->card_int_gpio = cd_gpio;
  56}
  57
  58static int sdhci_probe(struct platform_device *pdev)
  59{
  60        struct sdhci_host *host;
  61        struct resource *iomem;
  62        struct spear_sdhci *sdhci;
  63        struct device *dev;
  64        int ret;
  65
  66        dev = pdev->dev.parent ? pdev->dev.parent : &pdev->dev;
  67        host = sdhci_alloc_host(dev, sizeof(*sdhci));
  68        if (IS_ERR(host)) {
  69                ret = PTR_ERR(host);
  70                dev_dbg(&pdev->dev, "cannot allocate memory for sdhci\n");
  71                goto err;
  72        }
  73
  74        iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  75        host->ioaddr = devm_ioremap_resource(&pdev->dev, iomem);
  76        if (IS_ERR(host->ioaddr)) {
  77                ret = PTR_ERR(host->ioaddr);
  78                dev_dbg(&pdev->dev, "unable to map iomem: %d\n", ret);
  79                goto err_host;
  80        }
  81
  82        host->hw_name = "sdhci";
  83        host->ops = &sdhci_pltfm_ops;
  84        host->irq = platform_get_irq(pdev, 0);
  85        if (host->irq <= 0) {
  86                ret = -EINVAL;
  87                goto err_host;
  88        }
  89        host->quirks = SDHCI_QUIRK_BROKEN_ADMA;
  90
  91        sdhci = sdhci_priv(host);
  92
  93        /* clk enable */
  94        sdhci->clk = devm_clk_get(&pdev->dev, NULL);
  95        if (IS_ERR(sdhci->clk)) {
  96                ret = PTR_ERR(sdhci->clk);
  97                dev_dbg(&pdev->dev, "Error getting clock\n");
  98                goto err_host;
  99        }
 100
 101        ret = clk_prepare_enable(sdhci->clk);
 102        if (ret) {
 103                dev_dbg(&pdev->dev, "Error enabling clock\n");
 104                goto err_host;
 105        }
 106
 107        ret = clk_set_rate(sdhci->clk, 50000000);
 108        if (ret)
 109                dev_dbg(&pdev->dev, "Error setting desired clk, clk=%lu\n",
 110                                clk_get_rate(sdhci->clk));
 111
 112        sdhci_probe_config_dt(pdev->dev.of_node, sdhci);
 113        /*
 114         * It is optional to use GPIOs for sdhci card detection. If
 115         * sdhci->card_int_gpio < 0, then use original sdhci lines otherwise
 116         * GPIO lines. We use the built-in GPIO support for this.
 117         */
 118        if (sdhci->card_int_gpio >= 0) {
 119                ret = mmc_gpio_request_cd(host->mmc, sdhci->card_int_gpio, 0);
 120                if (ret < 0) {
 121                        dev_dbg(&pdev->dev,
 122                                "failed to request card-detect gpio%d\n",
 123                                sdhci->card_int_gpio);
 124                        goto disable_clk;
 125                }
 126        }
 127
 128        ret = sdhci_add_host(host);
 129        if (ret)
 130                goto disable_clk;
 131
 132        platform_set_drvdata(pdev, host);
 133
 134        return 0;
 135
 136disable_clk:
 137        clk_disable_unprepare(sdhci->clk);
 138err_host:
 139        sdhci_free_host(host);
 140err:
 141        dev_err(&pdev->dev, "spear-sdhci probe failed: %d\n", ret);
 142        return ret;
 143}
 144
 145static int sdhci_remove(struct platform_device *pdev)
 146{
 147        struct sdhci_host *host = platform_get_drvdata(pdev);
 148        struct spear_sdhci *sdhci = sdhci_priv(host);
 149        int dead = 0;
 150        u32 scratch;
 151
 152        scratch = readl(host->ioaddr + SDHCI_INT_STATUS);
 153        if (scratch == (u32)-1)
 154                dead = 1;
 155
 156        sdhci_remove_host(host, dead);
 157        clk_disable_unprepare(sdhci->clk);
 158        sdhci_free_host(host);
 159
 160        return 0;
 161}
 162
 163#ifdef CONFIG_PM_SLEEP
 164static int sdhci_suspend(struct device *dev)
 165{
 166        struct sdhci_host *host = dev_get_drvdata(dev);
 167        struct spear_sdhci *sdhci = sdhci_priv(host);
 168        int ret;
 169
 170        if (host->tuning_mode != SDHCI_TUNING_MODE_3)
 171                mmc_retune_needed(host->mmc);
 172
 173        ret = sdhci_suspend_host(host);
 174        if (!ret)
 175                clk_disable(sdhci->clk);
 176
 177        return ret;
 178}
 179
 180static int sdhci_resume(struct device *dev)
 181{
 182        struct sdhci_host *host = dev_get_drvdata(dev);
 183        struct spear_sdhci *sdhci = sdhci_priv(host);
 184        int ret;
 185
 186        ret = clk_enable(sdhci->clk);
 187        if (ret) {
 188                dev_dbg(dev, "Resume: Error enabling clock\n");
 189                return ret;
 190        }
 191
 192        return sdhci_resume_host(host);
 193}
 194#endif
 195
 196static SIMPLE_DEV_PM_OPS(sdhci_pm_ops, sdhci_suspend, sdhci_resume);
 197
 198#ifdef CONFIG_OF
 199static const struct of_device_id sdhci_spear_id_table[] = {
 200        { .compatible = "st,spear300-sdhci" },
 201        {}
 202};
 203MODULE_DEVICE_TABLE(of, sdhci_spear_id_table);
 204#endif
 205
 206static struct platform_driver sdhci_driver = {
 207        .driver = {
 208                .name   = "sdhci",
 209                .pm     = &sdhci_pm_ops,
 210                .of_match_table = of_match_ptr(sdhci_spear_id_table),
 211        },
 212        .probe          = sdhci_probe,
 213        .remove         = sdhci_remove,
 214};
 215
 216module_platform_driver(sdhci_driver);
 217
 218MODULE_DESCRIPTION("SPEAr Secure Digital Host Controller Interface driver");
 219MODULE_AUTHOR("Viresh Kumar <vireshk@kernel.org>");
 220MODULE_LICENSE("GPL v2");
 221