drivers/mmc/host/sdhci-spear.c

   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
  33 struct spear_sdhci {
  34         struct clk *clk;
  35         int card_int_gpio;
  36 };
  37
  38 /* sdhci ops */
  39 static 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
  46 static 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
  58 static 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         host->quirks = SDHCI_QUIRK_BROKEN_ADMA;
  86
  87         sdhci = sdhci_priv(host);
  88
  89         /* clk enable */
  90         sdhci->clk = devm_clk_get(&pdev->dev, NULL);
  91         if (IS_ERR(sdhci->clk)) {
  92                 ret = PTR_ERR(sdhci->clk);
  93                 dev_dbg(&pdev->dev, "Error getting clock\n");
  94                 goto err_host;
  95         }
  96
  97         ret = clk_prepare_enable(sdhci->clk);
  98         if (ret) {
  99                 dev_dbg(&pdev->dev, "Error enabling clock\n");
 100                 goto err_host;
 101         }
 102
 103         ret = clk_set_rate(sdhci->clk, 50000000);
 104         if (ret)
 105                 dev_dbg(&pdev->dev, "Error setting desired clk, clk=%lu\n",
 106                                 clk_get_rate(sdhci->clk));
 107
 108         sdhci_probe_config_dt(pdev->dev.of_node, sdhci);
 109         /*
 110          * It is optional to use GPIOs for sdhci card detection. If
 111          * sdhci->card_int_gpio < 0, then use original sdhci lines otherwise
 112          * GPIO lines. We use the built-in GPIO support for this.
 113          */
 114         if (sdhci->card_int_gpio >= 0) {
 115                 ret = mmc_gpio_request_cd(host->mmc, sdhci->card_int_gpio, 0);
 116                 if (ret < 0) {
 117                         dev_dbg(&pdev->dev,
 118                                 "failed to request card-detect gpio%d\n",
 119                                 sdhci->card_int_gpio);
 120                         goto disable_clk;
 121                 }
 122         }
 123
 124         ret = sdhci_add_host(host);
 125         if (ret) {
 126                 dev_dbg(&pdev->dev, "error adding host\n");
 127                 goto disable_clk;
 128         }
 129
 130         platform_set_drvdata(pdev, host);
 131
 132         return 0;
 133
 134 disable_clk:
 135         clk_disable_unprepare(sdhci->clk);
 136 err_host:
 137         sdhci_free_host(host);
 138 err:
 139         dev_err(&pdev->dev, "spear-sdhci probe failed: %d\n", ret);
 140         return ret;
 141 }
 142
 143 static int sdhci_remove(struct platform_device *pdev)
 144 {
 145         struct sdhci_host *host = platform_get_drvdata(pdev);
 146         struct spear_sdhci *sdhci = sdhci_priv(host);
 147         int dead = 0;
 148         u32 scratch;
 149
 150         scratch = readl(host->ioaddr + SDHCI_INT_STATUS);
 151         if (scratch == (u32)-1)
 152                 dead = 1;
 153
 154         sdhci_remove_host(host, dead);
 155         clk_disable_unprepare(sdhci->clk);
 156         sdhci_free_host(host);
 157
 158         return 0;
 159 }
 160
 161 #ifdef CONFIG_PM_SLEEP
 162 static int sdhci_suspend(struct device *dev)
 163 {
 164         struct sdhci_host *host = dev_get_drvdata(dev);
 165         struct spear_sdhci *sdhci = sdhci_priv(host);
 166         int ret;
 167
 168         ret = sdhci_suspend_host(host);
 169         if (!ret)
 170                 clk_disable(sdhci->clk);
 171
 172         return ret;
 173 }
 174
 175 static int sdhci_resume(struct device *dev)
 176 {
 177         struct sdhci_host *host = dev_get_drvdata(dev);
 178         struct spear_sdhci *sdhci = sdhci_priv(host);
 179         int ret;
 180
 181         ret = clk_enable(sdhci->clk);
 182         if (ret) {
 183                 dev_dbg(dev, "Resume: Error enabling clock\n");
 184                 return ret;
 185         }
 186
 187         return sdhci_resume_host(host);
 188 }
 189 #endif
 190
 191 static SIMPLE_DEV_PM_OPS(sdhci_pm_ops, sdhci_suspend, sdhci_resume);
 192
 193 #ifdef CONFIG_OF
 194 static const struct of_device_id sdhci_spear_id_table[] = {
 195         { .compatible = "st,spear300-sdhci" },
 196         {}
 197 };
 198 MODULE_DEVICE_TABLE(of, sdhci_spear_id_table);
 199 #endif
 200
 201 static struct platform_driver sdhci_driver = {
 202         .driver = {
 203                 .name   = "sdhci",
 204                 .pm     = &sdhci_pm_ops,
 205                 .of_match_table = of_match_ptr(sdhci_spear_id_table),
 206         },
 207         .probe          = sdhci_probe,
 208         .remove         = sdhci_remove,
 209 };
 210
 211 module_platform_driver(sdhci_driver);
 212
 213 MODULE_DESCRIPTION("SPEAr Secure Digital Host Controller Interface driver");
 214 MODULE_AUTHOR("Viresh Kumar <vireshk@kernel.org>");
 215 MODULE_LICENSE("GPL v2");