kernel/drivers/mmc/host/sdhci-of-arasan.c

   1 /*
   2  * Arasan Secure Digital Host Controller Interface.
   3  * Copyright (C) 2011 - 2012 Michal Simek <monstr@monstr.eu>
   4  * Copyright (c) 2012 Wind River Systems, Inc.
   5  * Copyright (C) 2013 Pengutronix e.K.
   6  * Copyright (C) 2013 Xilinx Inc.
   7  *
   8  * Based on sdhci-of-esdhc.c
   9  *
  10  * Copyright (c) 2007 Freescale Semiconductor, Inc.
  11  * Copyright (c) 2009 MontaVista Software, Inc.
  12  *
  13  * Authors: Xiaobo Xie <X.Xie@freescale.com>
  14  *          Anton Vorontsov <avorontsov@ru.mvista.com>
  15  *
  16  * This program is free software; you can redistribute it and/or modify
  17  * it under the terms of the GNU General Public License as published by
  18  * the Free Software Foundation; either version 2 of the License, or (at
  19  * your option) any later version.
  20  */
  21
  22 #include <linux/module.h>
  23 #include "sdhci-pltfm.h"
  24
  25 #define SDHCI_ARASAN_CLK_CTRL_OFFSET    0x2c
  26
  27 #define CLK_CTRL_TIMEOUT_SHIFT          16
  28 #define CLK_CTRL_TIMEOUT_MASK           (0xf << CLK_CTRL_TIMEOUT_SHIFT)
  29 #define CLK_CTRL_TIMEOUT_MIN_EXP        13
  30
  31 /**
  32  * struct sdhci_arasan_data
  33  * @clk_ahb:    Pointer to the AHB clock
  34  */
  35 struct sdhci_arasan_data {
  36         struct clk      *clk_ahb;
  37 };
  38
  39 static unsigned int sdhci_arasan_get_timeout_clock(struct sdhci_host *host)
  40 {
  41         u32 div;
  42         unsigned long freq;
  43         struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
  44
  45         div = readl(host->ioaddr + SDHCI_ARASAN_CLK_CTRL_OFFSET);
  46         div = (div & CLK_CTRL_TIMEOUT_MASK) >> CLK_CTRL_TIMEOUT_SHIFT;
  47
  48         freq = clk_get_rate(pltfm_host->clk);
  49         freq /= 1 << (CLK_CTRL_TIMEOUT_MIN_EXP + div);
  50
  51         return freq;
  52 }
  53
  54 static struct sdhci_ops sdhci_arasan_ops = {
  55         .set_clock = sdhci_set_clock,
  56         .get_max_clock = sdhci_pltfm_clk_get_max_clock,
  57         .get_timeout_clock = sdhci_arasan_get_timeout_clock,
  58         .set_bus_width = sdhci_set_bus_width,
  59         .reset = sdhci_reset,
  60         .set_uhs_signaling = sdhci_set_uhs_signaling,
  61 };
  62
  63 static struct sdhci_pltfm_data sdhci_arasan_pdata = {
  64         .ops = &sdhci_arasan_ops,
  65 };
  66
  67 #ifdef CONFIG_PM_SLEEP
  68 /**
  69  * sdhci_arasan_suspend - Suspend method for the driver
  70  * @dev:        Address of the device structure
  71  * Returns 0 on success and error value on error
  72  *
  73  * Put the device in a low power state.
  74  */
  75 static int sdhci_arasan_suspend(struct device *dev)
  76 {
  77         struct platform_device *pdev = to_platform_device(dev);
  78         struct sdhci_host *host = platform_get_drvdata(pdev);
  79         struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
  80         struct sdhci_arasan_data *sdhci_arasan = pltfm_host->priv;
  81         int ret;
  82
  83         ret = sdhci_suspend_host(host);
  84         if (ret)
  85                 return ret;
  86
  87         clk_disable(pltfm_host->clk);
  88         clk_disable(sdhci_arasan->clk_ahb);
  89
  90         return 0;
  91 }
  92
  93 /**
  94  * sdhci_arasan_resume - Resume method for the driver
  95  * @dev:        Address of the device structure
  96  * Returns 0 on success and error value on error
  97  *
  98  * Resume operation after suspend
  99  */
 100 static int sdhci_arasan_resume(struct device *dev)
 101 {
 102         struct platform_device *pdev = to_platform_device(dev);
 103         struct sdhci_host *host = platform_get_drvdata(pdev);
 104         struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
 105         struct sdhci_arasan_data *sdhci_arasan = pltfm_host->priv;
 106         int ret;
 107
 108         ret = clk_enable(sdhci_arasan->clk_ahb);
 109         if (ret) {
 110                 dev_err(dev, "Cannot enable AHB clock.\n");
 111                 return ret;
 112         }
 113
 114         ret = clk_enable(pltfm_host->clk);
 115         if (ret) {
 116                 dev_err(dev, "Cannot enable SD clock.\n");
 117                 clk_disable(sdhci_arasan->clk_ahb);
 118                 return ret;
 119         }
 120
 121         return sdhci_resume_host(host);
 122 }
 123 #endif /* ! CONFIG_PM_SLEEP */
 124
 125 static SIMPLE_DEV_PM_OPS(sdhci_arasan_dev_pm_ops, sdhci_arasan_suspend,
 126                          sdhci_arasan_resume);
 127
 128 static int sdhci_arasan_probe(struct platform_device *pdev)
 129 {
 130         int ret;
 131         struct clk *clk_xin;
 132         struct sdhci_host *host;
 133         struct sdhci_pltfm_host *pltfm_host;
 134         struct sdhci_arasan_data *sdhci_arasan;
 135
 136         sdhci_arasan = devm_kzalloc(&pdev->dev, sizeof(*sdhci_arasan),
 137                         GFP_KERNEL);
 138         if (!sdhci_arasan)
 139                 return -ENOMEM;
 140
 141         sdhci_arasan->clk_ahb = devm_clk_get(&pdev->dev, "clk_ahb");
 142         if (IS_ERR(sdhci_arasan->clk_ahb)) {
 143                 dev_err(&pdev->dev, "clk_ahb clock not found.\n");
 144                 return PTR_ERR(sdhci_arasan->clk_ahb);
 145         }
 146
 147         clk_xin = devm_clk_get(&pdev->dev, "clk_xin");
 148         if (IS_ERR(clk_xin)) {
 149                 dev_err(&pdev->dev, "clk_xin clock not found.\n");
 150                 return PTR_ERR(clk_xin);
 151         }
 152
 153         ret = clk_prepare_enable(sdhci_arasan->clk_ahb);
 154         if (ret) {
 155                 dev_err(&pdev->dev, "Unable to enable AHB clock.\n");
 156                 return ret;
 157         }
 158
 159         ret = clk_prepare_enable(clk_xin);
 160         if (ret) {
 161                 dev_err(&pdev->dev, "Unable to enable SD clock.\n");
 162                 goto clk_dis_ahb;
 163         }
 164
 165         host = sdhci_pltfm_init(pdev, &sdhci_arasan_pdata, 0);
 166         if (IS_ERR(host)) {
 167                 ret = PTR_ERR(host);
 168                 goto clk_disable_all;
 169         }
 170
 171         sdhci_get_of_property(pdev);
 172         pltfm_host = sdhci_priv(host);
 173         pltfm_host->priv = sdhci_arasan;
 174         pltfm_host->clk = clk_xin;
 175
 176         ret = mmc_of_parse(host->mmc);
 177         if (ret) {
 178                 dev_err(&pdev->dev, "parsing dt failed (%u)\n", ret);
 179                 goto clk_disable_all;
 180         }
 181
 182         ret = sdhci_add_host(host);
 183         if (ret)
 184                 goto err_pltfm_free;
 185
 186         return 0;
 187
 188 err_pltfm_free:
 189         sdhci_pltfm_free(pdev);
 190 clk_disable_all:
 191         clk_disable_unprepare(clk_xin);
 192 clk_dis_ahb:
 193         clk_disable_unprepare(sdhci_arasan->clk_ahb);
 194
 195         return ret;
 196 }
 197
 198 static int sdhci_arasan_remove(struct platform_device *pdev)
 199 {
 200         struct sdhci_host *host = platform_get_drvdata(pdev);
 201         struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
 202         struct sdhci_arasan_data *sdhci_arasan = pltfm_host->priv;
 203
 204         clk_disable_unprepare(sdhci_arasan->clk_ahb);
 205
 206         return sdhci_pltfm_unregister(pdev);
 207 }
 208
 209 static const struct of_device_id sdhci_arasan_of_match[] = {
 210         { .compatible = "arasan,sdhci-8.9a" },
 211         { }
 212 };
 213 MODULE_DEVICE_TABLE(of, sdhci_arasan_of_match);
 214
 215 static struct platform_driver sdhci_arasan_driver = {
 216         .driver = {
 217                 .name = "sdhci-arasan",
 218                 .of_match_table = sdhci_arasan_of_match,
 219                 .pm = &sdhci_arasan_dev_pm_ops,
 220         },
 221         .probe = sdhci_arasan_probe,
 222         .remove = sdhci_arasan_remove,
 223 };
 224
 225 module_platform_driver(sdhci_arasan_driver);
 226
 227 MODULE_DESCRIPTION("Driver for the Arasan SDHCI Controller");
 228 MODULE_AUTHOR("Soeren Brinkmann <soren.brinkmann@xilinx.com>");
 229 MODULE_LICENSE("GPL");