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         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
 136 disable_clk:
 137         clk_disable_unprepare(sdhci->clk);
 138 err_host:
 139         sdhci_free_host(host);
 140 err:
 141         dev_err(&pdev->dev, "spear-sdhci probe failed: %d\n", ret);
 142         return ret;
 143 }
 144
 145 static 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
 164 static 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
 180 static 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
 196 static SIMPLE_DEV_PM_OPS(sdhci_pm_ops, sdhci_suspend, sdhci_resume);
 197
 198 #ifdef CONFIG_OF
 199 static const struct of_device_id sdhci_spear_id_table[] = {
 200         { .compatible = "st,spear300-sdhci" },
 201         {}
 202 };
 203 MODULE_DEVICE_TABLE(of, sdhci_spear_id_table);
 204 #endif
 205
 206 static 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
 216 module_platform_driver(sdhci_driver);
 217
 218 MODULE_DESCRIPTION("SPEAr Secure Digital Host Controller Interface driver");
 219 MODULE_AUTHOR("Viresh Kumar <vireshk@kernel.org>");
 220 MODULE_LICENSE("GPL v2");