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 };
  61
  62 static struct sdhci_pltfm_data sdhci_arasan_pdata = {
  63         .ops = &sdhci_arasan_ops,
  64 };
  65
  66 #ifdef CONFIG_PM_SLEEP
  67 /**
  68  * sdhci_arasan_suspend - Suspend method for the driver
  69  * @dev:        Address of the device structure
  70  * Returns 0 on success and error value on error
  71  *
  72  * Put the device in a low power state.
  73  */
  74 static int sdhci_arasan_suspend(struct device *dev)
  75 {
  76         struct platform_device *pdev = to_platform_device(dev);
  77         struct sdhci_host *host = platform_get_drvdata(pdev);
  78         struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
  79         struct sdhci_arasan_data *sdhci_arasan = pltfm_host->priv;
  80         int ret;
  81
  82         ret = sdhci_suspend_host(host);
  83         if (ret)
  84                 return ret;
  85
  86         clk_disable(pltfm_host->clk);
  87         clk_disable(sdhci_arasan->clk_ahb);
  88
  89         return 0;
  90 }
  91
  92 /**
  93  * sdhci_arasan_resume - Resume method for the driver
  94  * @dev:        Address of the device structure
  95  * Returns 0 on success and error value on error
  96  *
  97  * Resume operation after suspend
  98  */
  99 static int sdhci_arasan_resume(struct device *dev)
 100 {
 101         struct platform_device *pdev = to_platform_device(dev);
 102         struct sdhci_host *host = platform_get_drvdata(pdev);
 103         struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
 104         struct sdhci_arasan_data *sdhci_arasan = pltfm_host->priv;
 105         int ret;
 106
 107         ret = clk_enable(sdhci_arasan->clk_ahb);
 108         if (ret) {
 109                 dev_err(dev, "Cannot enable AHB clock.\n");
 110                 return ret;
 111         }
 112
 113         ret = clk_enable(pltfm_host->clk);
 114         if (ret) {
 115                 dev_err(dev, "Cannot enable SD clock.\n");
 116                 clk_disable(sdhci_arasan->clk_ahb);
 117                 return ret;
 118         }
 119
 120         return sdhci_resume_host(host);
 121 }
 122 #endif /* ! CONFIG_PM_SLEEP */
 123
 124 static SIMPLE_DEV_PM_OPS(sdhci_arasan_dev_pm_ops, sdhci_arasan_suspend,
 125                          sdhci_arasan_resume);
 126
 127 static int sdhci_arasan_probe(struct platform_device *pdev)
 128 {
 129         int ret;
 130         struct clk *clk_xin;
 131         struct sdhci_host *host;
 132         struct sdhci_pltfm_host *pltfm_host;
 133         struct sdhci_arasan_data *sdhci_arasan;
 134
 135         sdhci_arasan = devm_kzalloc(&pdev->dev, sizeof(*sdhci_arasan),
 136                         GFP_KERNEL);
 137         if (!sdhci_arasan)
 138                 return -ENOMEM;
 139
 140         sdhci_arasan->clk_ahb = devm_clk_get(&pdev->dev, "clk_ahb");
 141         if (IS_ERR(sdhci_arasan->clk_ahb)) {
 142                 dev_err(&pdev->dev, "clk_ahb clock not found.\n");
 143                 return PTR_ERR(sdhci_arasan->clk_ahb);
 144         }
 145
 146         clk_xin = devm_clk_get(&pdev->dev, "clk_xin");
 147         if (IS_ERR(clk_xin)) {
 148                 dev_err(&pdev->dev, "clk_xin clock not found.\n");
 149                 return PTR_ERR(clk_xin);
 150         }
 151
 152         ret = clk_prepare_enable(sdhci_arasan->clk_ahb);
 153         if (ret) {
 154                 dev_err(&pdev->dev, "Unable to enable AHB clock.\n");
 155                 return ret;
 156         }
 157
 158         ret = clk_prepare_enable(clk_xin);
 159         if (ret) {
 160                 dev_err(&pdev->dev, "Unable to enable SD clock.\n");
 161                 goto clk_dis_ahb;
 162         }
 163
 164         host = sdhci_pltfm_init(pdev, &sdhci_arasan_pdata, 0);
 165         if (IS_ERR(host)) {
 166                 ret = PTR_ERR(host);
 167                 dev_err(&pdev->dev, "platform init failed (%u)\n", ret);
 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 = sdhci_add_host(host);
 177         if (ret) {
 178                 dev_err(&pdev->dev, "platform register failed (%u)\n", ret);
 179                 goto err_pltfm_free;
 180         }
 181
 182         return 0;
 183
 184 err_pltfm_free:
 185         sdhci_pltfm_free(pdev);
 186 clk_disable_all:
 187         clk_disable_unprepare(clk_xin);
 188 clk_dis_ahb:
 189         clk_disable_unprepare(sdhci_arasan->clk_ahb);
 190
 191         return ret;
 192 }
 193
 194 static int sdhci_arasan_remove(struct platform_device *pdev)
 195 {
 196         struct sdhci_host *host = platform_get_drvdata(pdev);
 197         struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
 198         struct sdhci_arasan_data *sdhci_arasan = pltfm_host->priv;
 199
 200         clk_disable_unprepare(pltfm_host->clk);
 201         clk_disable_unprepare(sdhci_arasan->clk_ahb);
 202
 203         return sdhci_pltfm_unregister(pdev);
 204 }
 205
 206 static const struct of_device_id sdhci_arasan_of_match[] = {
 207         { .compatible = "arasan,sdhci-8.9a" },
 208         { }
 209 };
 210 MODULE_DEVICE_TABLE(of, sdhci_arasan_of_match);
 211
 212 static struct platform_driver sdhci_arasan_driver = {
 213         .driver = {
 214                 .name = "sdhci-arasan",
 215                 .owner = THIS_MODULE,
 216                 .of_match_table = sdhci_arasan_of_match,
 217                 .pm = &sdhci_arasan_dev_pm_ops,
 218         },
 219         .probe = sdhci_arasan_probe,
 220         .remove = sdhci_arasan_remove,
 221 };
 222
 223 module_platform_driver(sdhci_arasan_driver);
 224
 225 MODULE_DESCRIPTION("Driver for the Arasan SDHCI Controller");
 226 MODULE_AUTHOR("Soeren Brinkmann <soren.brinkmann@xilinx.com>");
 227 MODULE_LICENSE("GPL");