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/highmem.h>
  19 #include <linux/module.h>
  20 #include <linux/interrupt.h>
  21 #include <linux/irq.h>
  22 #include <linux/of.h>
  23 #include <linux/platform_device.h>
  24 #include <linux/pm.h>
  25 #include <linux/slab.h>
  26 #include <linux/mmc/host.h>
  27 #include <linux/mmc/slot-gpio.h>
  28 #include <linux/io.h>
  29 #include "sdhci.h"
  30
  31 struct spear_sdhci {
  32         struct clk *clk;
  33 };
  34
  35 /* sdhci ops */
  36 static const struct sdhci_ops sdhci_pltfm_ops = {
  37         .set_clock = sdhci_set_clock,
  38         .set_bus_width = sdhci_set_bus_width,
  39         .reset = sdhci_reset,
  40         .set_uhs_signaling = sdhci_set_uhs_signaling,
  41 };
  42
  43 static int sdhci_probe(struct platform_device *pdev)
  44 {
  45         struct sdhci_host *host;
  46         struct resource *iomem;
  47         struct spear_sdhci *sdhci;
  48         struct device *dev;
  49         int ret;
  50
  51         dev = pdev->dev.parent ? pdev->dev.parent : &pdev->dev;
  52         host = sdhci_alloc_host(dev, sizeof(*sdhci));
  53         if (IS_ERR(host)) {
  54                 ret = PTR_ERR(host);
  55                 dev_dbg(&pdev->dev, "cannot allocate memory for sdhci\n");
  56                 goto err;
  57         }
  58
  59         iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  60         host->ioaddr = devm_ioremap_resource(&pdev->dev, iomem);
  61         if (IS_ERR(host->ioaddr)) {
  62                 ret = PTR_ERR(host->ioaddr);
  63                 dev_dbg(&pdev->dev, "unable to map iomem: %d\n", ret);
  64                 goto err_host;
  65         }
  66
  67         host->hw_name = "sdhci";
  68         host->ops = &sdhci_pltfm_ops;
  69         host->irq = platform_get_irq(pdev, 0);
  70         if (host->irq <= 0) {
  71                 ret = -EINVAL;
  72                 goto err_host;
  73         }
  74         host->quirks = SDHCI_QUIRK_BROKEN_ADMA;
  75
  76         sdhci = sdhci_priv(host);
  77
  78         /* clk enable */
  79         sdhci->clk = devm_clk_get(&pdev->dev, NULL);
  80         if (IS_ERR(sdhci->clk)) {
  81                 ret = PTR_ERR(sdhci->clk);
  82                 dev_dbg(&pdev->dev, "Error getting clock\n");
  83                 goto err_host;
  84         }
  85
  86         ret = clk_prepare_enable(sdhci->clk);
  87         if (ret) {
  88                 dev_dbg(&pdev->dev, "Error enabling clock\n");
  89                 goto err_host;
  90         }
  91
  92         ret = clk_set_rate(sdhci->clk, 50000000);
  93         if (ret)
  94                 dev_dbg(&pdev->dev, "Error setting desired clk, clk=%lu\n",
  95                                 clk_get_rate(sdhci->clk));
  96
  97         /*
  98          * It is optional to use GPIOs for sdhci card detection. If we
  99          * find a descriptor using slot GPIO, we use it.
 100          */
 101         ret = mmc_gpiod_request_cd(host->mmc, "cd", 0, false, 0, NULL);
 102         if (ret == -EPROBE_DEFER)
 103                 goto disable_clk;
 104
 105         ret = sdhci_add_host(host);
 106         if (ret)
 107                 goto disable_clk;
 108
 109         platform_set_drvdata(pdev, host);
 110
 111         return 0;
 112
 113 disable_clk:
 114         clk_disable_unprepare(sdhci->clk);
 115 err_host:
 116         sdhci_free_host(host);
 117 err:
 118         dev_err(&pdev->dev, "spear-sdhci probe failed: %d\n", ret);
 119         return ret;
 120 }
 121
 122 static int sdhci_remove(struct platform_device *pdev)
 123 {
 124         struct sdhci_host *host = platform_get_drvdata(pdev);
 125         struct spear_sdhci *sdhci = sdhci_priv(host);
 126         int dead = 0;
 127         u32 scratch;
 128
 129         scratch = readl(host->ioaddr + SDHCI_INT_STATUS);
 130         if (scratch == (u32)-1)
 131                 dead = 1;
 132
 133         sdhci_remove_host(host, dead);
 134         clk_disable_unprepare(sdhci->clk);
 135         sdhci_free_host(host);
 136
 137         return 0;
 138 }
 139
 140 #ifdef CONFIG_PM_SLEEP
 141 static int sdhci_suspend(struct device *dev)
 142 {
 143         struct sdhci_host *host = dev_get_drvdata(dev);
 144         struct spear_sdhci *sdhci = sdhci_priv(host);
 145         int ret;
 146
 147         if (host->tuning_mode != SDHCI_TUNING_MODE_3)
 148                 mmc_retune_needed(host->mmc);
 149
 150         ret = sdhci_suspend_host(host);
 151         if (!ret)
 152                 clk_disable(sdhci->clk);
 153
 154         return ret;
 155 }
 156
 157 static int sdhci_resume(struct device *dev)
 158 {
 159         struct sdhci_host *host = dev_get_drvdata(dev);
 160         struct spear_sdhci *sdhci = sdhci_priv(host);
 161         int ret;
 162
 163         ret = clk_enable(sdhci->clk);
 164         if (ret) {
 165                 dev_dbg(dev, "Resume: Error enabling clock\n");
 166                 return ret;
 167         }
 168
 169         return sdhci_resume_host(host);
 170 }
 171 #endif
 172
 173 static SIMPLE_DEV_PM_OPS(sdhci_pm_ops, sdhci_suspend, sdhci_resume);
 174
 175 #ifdef CONFIG_OF
 176 static const struct of_device_id sdhci_spear_id_table[] = {
 177         { .compatible = "st,spear300-sdhci" },
 178         {}
 179 };
 180 MODULE_DEVICE_TABLE(of, sdhci_spear_id_table);
 181 #endif
 182
 183 static struct platform_driver sdhci_driver = {
 184         .driver = {
 185                 .name   = "sdhci",
 186                 .pm     = &sdhci_pm_ops,
 187                 .of_match_table = of_match_ptr(sdhci_spear_id_table),
 188         },
 189         .probe          = sdhci_probe,
 190         .remove         = sdhci_remove,
 191 };
 192
 193 module_platform_driver(sdhci_driver);
 194
 195 MODULE_DESCRIPTION("SPEAr Secure Digital Host Controller Interface driver");
 196 MODULE_AUTHOR("Viresh Kumar <vireshk@kernel.org>");
 197 MODULE_LICENSE("GPL v2");