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

   1 /*
   2  * Arasan Secure Digital Host Controller Interface.
   3  * Copyright (C) 2011 - 2012 Michal Simek <[email protected]>
   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 <[email protected]>
  14  *          Anton Vorontsov <[email protected]>
  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 };
  58
  59 static struct sdhci_pltfm_data sdhci_arasan_pdata = {
  60         .ops = &sdhci_arasan_ops,
  61 };
  62
  63 #ifdef CONFIG_PM_SLEEP
  64 /**
  65  * sdhci_arasan_suspend - Suspend method for the driver
  66  * @dev:        Address of the device structure
  67  * Returns 0 on success and error value on error
  68  *
  69  * Put the device in a low power state.
  70  */
  71 static int sdhci_arasan_suspend(struct device *dev)
  72 {
  73         struct platform_device *pdev = to_platform_device(dev);
  74         struct sdhci_host *host = platform_get_drvdata(pdev);
  75         struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
  76         struct sdhci_arasan_data *sdhci_arasan = pltfm_host->priv;
  77         int ret;
  78
  79         ret = sdhci_suspend_host(host);
  80         if (ret)
  81                 return ret;
  82
  83         clk_disable(pltfm_host->clk);
  84         clk_disable(sdhci_arasan->clk_ahb);
  85
  86         return 0;
  87 }
  88
  89 /**
  90  * sdhci_arasan_resume - Resume method for the driver
  91  * @dev:        Address of the device structure
  92  * Returns 0 on success and error value on error
  93  *
  94  * Resume operation after suspend
  95  */
  96 static int sdhci_arasan_resume(struct device *dev)
  97 {
  98         struct platform_device *pdev = to_platform_device(dev);
  99         struct sdhci_host *host = platform_get_drvdata(pdev);
 100         struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
 101         struct sdhci_arasan_data *sdhci_arasan = pltfm_host->priv;
 102         int ret;
 103
 104         ret = clk_enable(sdhci_arasan->clk_ahb);
 105         if (ret) {
 106                 dev_err(dev, "Cannot enable AHB clock.\n");
 107                 return ret;
 108         }
 109
 110         ret = clk_enable(pltfm_host->clk);
 111         if (ret) {
 112                 dev_err(dev, "Cannot enable SD clock.\n");
 113                 clk_disable(sdhci_arasan->clk_ahb);
 114                 return ret;
 115         }
 116
 117         return sdhci_resume_host(host);
 118 }
 119 #endif /* ! CONFIG_PM_SLEEP */
 120
 121 static SIMPLE_DEV_PM_OPS(sdhci_arasan_dev_pm_ops, sdhci_arasan_suspend,
 122                          sdhci_arasan_resume);
 123
 124 static int sdhci_arasan_probe(struct platform_device *pdev)
 125 {
 126         int ret;
 127         struct clk *clk_xin;
 128         struct sdhci_host *host;
 129         struct sdhci_pltfm_host *pltfm_host;
 130         struct sdhci_arasan_data *sdhci_arasan;
 131
 132         sdhci_arasan = devm_kzalloc(&pdev->dev, sizeof(*sdhci_arasan),
 133                         GFP_KERNEL);
 134         if (!sdhci_arasan)
 135                 return -ENOMEM;
 136
 137         sdhci_arasan->clk_ahb = devm_clk_get(&pdev->dev, "clk_ahb");
 138         if (IS_ERR(sdhci_arasan->clk_ahb)) {
 139                 dev_err(&pdev->dev, "clk_ahb clock not found.\n");
 140                 return PTR_ERR(sdhci_arasan->clk_ahb);
 141         }
 142
 143         clk_xin = devm_clk_get(&pdev->dev, "clk_xin");
 144         if (IS_ERR(clk_xin)) {
 145                 dev_err(&pdev->dev, "clk_xin clock not found.\n");
 146                 return PTR_ERR(clk_xin);
 147         }
 148
 149         ret = clk_prepare_enable(sdhci_arasan->clk_ahb);
 150         if (ret) {
 151                 dev_err(&pdev->dev, "Unable to enable AHB clock.\n");
 152                 return ret;
 153         }
 154
 155         ret = clk_prepare_enable(clk_xin);
 156         if (ret) {
 157                 dev_err(&pdev->dev, "Unable to enable SD clock.\n");
 158                 goto clk_dis_ahb;
 159         }
 160
 161         host = sdhci_pltfm_init(pdev, &sdhci_arasan_pdata, 0);
 162         if (IS_ERR(host)) {
 163                 ret = PTR_ERR(host);
 164                 dev_err(&pdev->dev, "platform init failed (%u)\n", ret);
 165                 goto clk_disable_all;
 166         }
 167
 168         sdhci_get_of_property(pdev);
 169         pltfm_host = sdhci_priv(host);
 170         pltfm_host->priv = sdhci_arasan;
 171         pltfm_host->clk = clk_xin;
 172
 173         ret = sdhci_add_host(host);
 174         if (ret) {
 175                 dev_err(&pdev->dev, "platform register failed (%u)\n", ret);
 176                 goto err_pltfm_free;
 177         }
 178
 179         return 0;
 180
 181 err_pltfm_free:
 182         sdhci_pltfm_free(pdev);
 183 clk_disable_all:
 184         clk_disable_unprepare(clk_xin);
 185 clk_dis_ahb:
 186         clk_disable_unprepare(sdhci_arasan->clk_ahb);
 187
 188         return ret;
 189 }
 190
 191 static int sdhci_arasan_remove(struct platform_device *pdev)
 192 {
 193         struct sdhci_host *host = platform_get_drvdata(pdev);
 194         struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
 195         struct sdhci_arasan_data *sdhci_arasan = pltfm_host->priv;
 196
 197         clk_disable_unprepare(pltfm_host->clk);
 198         clk_disable_unprepare(sdhci_arasan->clk_ahb);
 199
 200         return sdhci_pltfm_unregister(pdev);
 201 }
 202
 203 static const struct of_device_id sdhci_arasan_of_match[] = {
 204         { .compatible = "arasan,sdhci-8.9a" },
 205         { }
 206 };
 207 MODULE_DEVICE_TABLE(of, sdhci_arasan_of_match);
 208
 209 static struct platform_driver sdhci_arasan_driver = {
 210         .driver = {
 211                 .name = "sdhci-arasan",
 212                 .owner = THIS_MODULE,
 213                 .of_match_table = sdhci_arasan_of_match,
 214                 .pm = &sdhci_arasan_dev_pm_ops,
 215         },
 216         .probe = sdhci_arasan_probe,
 217         .remove = sdhci_arasan_remove,
 218 };
 219
 220 module_platform_driver(sdhci_arasan_driver);
 221
 222 MODULE_DESCRIPTION("Driver for the Arasan SDHCI Controller");
 223 MODULE_AUTHOR("Soeren Brinkmann <[email protected]>");
 224 MODULE_LICENSE("GPL");