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         .get_max_clock = sdhci_pltfm_clk_get_max_clock,
  56         .get_timeout_clock = sdhci_arasan_get_timeout_clock,
  57         .set_bus_width = sdhci_set_bus_width,
  58         .reset = sdhci_reset,
  59 };
  60
  61 static struct sdhci_pltfm_data sdhci_arasan_pdata = {
  62         .ops = &sdhci_arasan_ops,
  63 };
  64
  65 #ifdef CONFIG_PM_SLEEP
  66 /**
  67  * sdhci_arasan_suspend - Suspend method for the driver
  68  * @dev:        Address of the device structure
  69  * Returns 0 on success and error value on error
  70  *
  71  * Put the device in a low power state.
  72  */
  73 static int sdhci_arasan_suspend(struct device *dev)
  74 {
  75         struct platform_device *pdev = to_platform_device(dev);
  76         struct sdhci_host *host = platform_get_drvdata(pdev);
  77         struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
  78         struct sdhci_arasan_data *sdhci_arasan = pltfm_host->priv;
  79         int ret;
  80
  81         ret = sdhci_suspend_host(host);
  82         if (ret)
  83                 return ret;
  84
  85         clk_disable(pltfm_host->clk);
  86         clk_disable(sdhci_arasan->clk_ahb);
  87
  88         return 0;
  89 }
  90
  91 /**
  92  * sdhci_arasan_resume - Resume method for the driver
  93  * @dev:        Address of the device structure
  94  * Returns 0 on success and error value on error
  95  *
  96  * Resume operation after suspend
  97  */
  98 static int sdhci_arasan_resume(struct device *dev)
  99 {
 100         struct platform_device *pdev = to_platform_device(dev);
 101         struct sdhci_host *host = platform_get_drvdata(pdev);
 102         struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
 103         struct sdhci_arasan_data *sdhci_arasan = pltfm_host->priv;
 104         int ret;
 105
 106         ret = clk_enable(sdhci_arasan->clk_ahb);
 107         if (ret) {
 108                 dev_err(dev, "Cannot enable AHB clock.\n");
 109                 return ret;
 110         }
 111
 112         ret = clk_enable(pltfm_host->clk);
 113         if (ret) {
 114                 dev_err(dev, "Cannot enable SD clock.\n");
 115                 clk_disable(sdhci_arasan->clk_ahb);
 116                 return ret;
 117         }
 118
 119         return sdhci_resume_host(host);
 120 }
 121 #endif /* ! CONFIG_PM_SLEEP */
 122
 123 static SIMPLE_DEV_PM_OPS(sdhci_arasan_dev_pm_ops, sdhci_arasan_suspend,
 124                          sdhci_arasan_resume);
 125
 126 static int sdhci_arasan_probe(struct platform_device *pdev)
 127 {
 128         int ret;
 129         struct clk *clk_xin;
 130         struct sdhci_host *host;
 131         struct sdhci_pltfm_host *pltfm_host;
 132         struct sdhci_arasan_data *sdhci_arasan;
 133
 134         sdhci_arasan = devm_kzalloc(&pdev->dev, sizeof(*sdhci_arasan),
 135                         GFP_KERNEL);
 136         if (!sdhci_arasan)
 137                 return -ENOMEM;
 138
 139         sdhci_arasan->clk_ahb = devm_clk_get(&pdev->dev, "clk_ahb");
 140         if (IS_ERR(sdhci_arasan->clk_ahb)) {
 141                 dev_err(&pdev->dev, "clk_ahb clock not found.\n");
 142                 return PTR_ERR(sdhci_arasan->clk_ahb);
 143         }
 144
 145         clk_xin = devm_clk_get(&pdev->dev, "clk_xin");
 146         if (IS_ERR(clk_xin)) {
 147                 dev_err(&pdev->dev, "clk_xin clock not found.\n");
 148                 return PTR_ERR(clk_xin);
 149         }
 150
 151         ret = clk_prepare_enable(sdhci_arasan->clk_ahb);
 152         if (ret) {
 153                 dev_err(&pdev->dev, "Unable to enable AHB clock.\n");
 154                 return ret;
 155         }
 156
 157         ret = clk_prepare_enable(clk_xin);
 158         if (ret) {
 159                 dev_err(&pdev->dev, "Unable to enable SD clock.\n");
 160                 goto clk_dis_ahb;
 161         }
 162
 163         host = sdhci_pltfm_init(pdev, &sdhci_arasan_pdata, 0);
 164         if (IS_ERR(host)) {
 165                 ret = PTR_ERR(host);
 166                 dev_err(&pdev->dev, "platform init failed (%u)\n", ret);
 167                 goto clk_disable_all;
 168         }
 169
 170         sdhci_get_of_property(pdev);
 171         pltfm_host = sdhci_priv(host);
 172         pltfm_host->priv = sdhci_arasan;
 173         pltfm_host->clk = clk_xin;
 174
 175         ret = sdhci_add_host(host);
 176         if (ret) {
 177                 dev_err(&pdev->dev, "platform register failed (%u)\n", ret);
 178                 goto err_pltfm_free;
 179         }
 180
 181         return 0;
 182
 183 err_pltfm_free:
 184         sdhci_pltfm_free(pdev);
 185 clk_disable_all:
 186         clk_disable_unprepare(clk_xin);
 187 clk_dis_ahb:
 188         clk_disable_unprepare(sdhci_arasan->clk_ahb);
 189
 190         return ret;
 191 }
 192
 193 static int sdhci_arasan_remove(struct platform_device *pdev)
 194 {
 195         struct sdhci_host *host = platform_get_drvdata(pdev);
 196         struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
 197         struct sdhci_arasan_data *sdhci_arasan = pltfm_host->priv;
 198
 199         clk_disable_unprepare(pltfm_host->clk);
 200         clk_disable_unprepare(sdhci_arasan->clk_ahb);
 201
 202         return sdhci_pltfm_unregister(pdev);
 203 }
 204
 205 static const struct of_device_id sdhci_arasan_of_match[] = {
 206         { .compatible = "arasan,sdhci-8.9a" },
 207         { }
 208 };
 209 MODULE_DEVICE_TABLE(of, sdhci_arasan_of_match);
 210
 211 static struct platform_driver sdhci_arasan_driver = {
 212         .driver = {
 213                 .name = "sdhci-arasan",
 214                 .owner = THIS_MODULE,
 215                 .of_match_table = sdhci_arasan_of_match,
 216                 .pm = &sdhci_arasan_dev_pm_ops,
 217         },
 218         .probe = sdhci_arasan_probe,
 219         .remove = sdhci_arasan_remove,
 220 };
 221
 222 module_platform_driver(sdhci_arasan_driver);
 223
 224 MODULE_DESCRIPTION("Driver for the Arasan SDHCI Controller");
 225 MODULE_AUTHOR("Soeren Brinkmann <soren.brinkmann@xilinx.com>");
 226 MODULE_LICENSE("GPL");