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