linux/drivers/mmc/host/dw_mmc-exynos.c
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   1/*
   2 * Exynos Specific Extensions for Synopsys DW Multimedia Card Interface driver
   3 *
   4 * Copyright (C) 2012, Samsung Electronics Co., Ltd.
   5 *
   6 * This program is free software; you can redistribute it and/or modify
   7 * it under the terms of the GNU General Public License as published by
   8 * the Free Software Foundation; either version 2 of the License, or
   9 * (at your option) any later version.
  10 */
  11
  12#include <linux/module.h>
  13#include <linux/platform_device.h>
  14#include <linux/clk.h>
  15#include <linux/mmc/host.h>
  16#include <linux/mmc/dw_mmc.h>
  17#include <linux/of.h>
  18#include <linux/of_gpio.h>
  19
  20#include "dw_mmc.h"
  21#include "dw_mmc-pltfm.h"
  22
  23#define NUM_PINS(x)                     (x + 2)
  24
  25#define SDMMC_CLKSEL                    0x09C
  26#define SDMMC_CLKSEL_CCLK_SAMPLE(x)     (((x) & 7) << 0)
  27#define SDMMC_CLKSEL_CCLK_DRIVE(x)      (((x) & 7) << 16)
  28#define SDMMC_CLKSEL_CCLK_DIVIDER(x)    (((x) & 7) << 24)
  29#define SDMMC_CLKSEL_GET_DRV_WD3(x)     (((x) >> 16) & 0x7)
  30#define SDMMC_CLKSEL_TIMING(x, y, z)    (SDMMC_CLKSEL_CCLK_SAMPLE(x) |  \
  31                                        SDMMC_CLKSEL_CCLK_DRIVE(y) |    \
  32                                        SDMMC_CLKSEL_CCLK_DIVIDER(z))
  33
  34#define SDMMC_CMD_USE_HOLD_REG          BIT(29)
  35
  36#define EXYNOS4210_FIXED_CIU_CLK_DIV    2
  37#define EXYNOS4412_FIXED_CIU_CLK_DIV    4
  38
  39/* Variations in Exynos specific dw-mshc controller */
  40enum dw_mci_exynos_type {
  41        DW_MCI_TYPE_EXYNOS4210,
  42        DW_MCI_TYPE_EXYNOS4412,
  43        DW_MCI_TYPE_EXYNOS5250,
  44};
  45
  46/* Exynos implementation specific driver private data */
  47struct dw_mci_exynos_priv_data {
  48        enum dw_mci_exynos_type         ctrl_type;
  49        u8                              ciu_div;
  50        u32                             sdr_timing;
  51        u32                             ddr_timing;
  52};
  53
  54static struct dw_mci_exynos_compatible {
  55        char                            *compatible;
  56        enum dw_mci_exynos_type         ctrl_type;
  57} exynos_compat[] = {
  58        {
  59                .compatible     = "samsung,exynos4210-dw-mshc",
  60                .ctrl_type      = DW_MCI_TYPE_EXYNOS4210,
  61        }, {
  62                .compatible     = "samsung,exynos4412-dw-mshc",
  63                .ctrl_type      = DW_MCI_TYPE_EXYNOS4412,
  64        }, {
  65                .compatible     = "samsung,exynos5250-dw-mshc",
  66                .ctrl_type      = DW_MCI_TYPE_EXYNOS5250,
  67        },
  68};
  69
  70static int dw_mci_exynos_priv_init(struct dw_mci *host)
  71{
  72        struct dw_mci_exynos_priv_data *priv;
  73        int idx;
  74
  75        priv = devm_kzalloc(host->dev, sizeof(*priv), GFP_KERNEL);
  76        if (!priv) {
  77                dev_err(host->dev, "mem alloc failed for private data\n");
  78                return -ENOMEM;
  79        }
  80
  81        for (idx = 0; idx < ARRAY_SIZE(exynos_compat); idx++) {
  82                if (of_device_is_compatible(host->dev->of_node,
  83                                        exynos_compat[idx].compatible))
  84                        priv->ctrl_type = exynos_compat[idx].ctrl_type;
  85        }
  86
  87        host->priv = priv;
  88        return 0;
  89}
  90
  91static int dw_mci_exynos_setup_clock(struct dw_mci *host)
  92{
  93        struct dw_mci_exynos_priv_data *priv = host->priv;
  94
  95        if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS5250)
  96                host->bus_hz /= (priv->ciu_div + 1);
  97        else if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS4412)
  98                host->bus_hz /= EXYNOS4412_FIXED_CIU_CLK_DIV;
  99        else if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS4210)
 100                host->bus_hz /= EXYNOS4210_FIXED_CIU_CLK_DIV;
 101
 102        return 0;
 103}
 104
 105static void dw_mci_exynos_prepare_command(struct dw_mci *host, u32 *cmdr)
 106{
 107        /*
 108         * Exynos4412 and Exynos5250 extends the use of CMD register with the
 109         * use of bit 29 (which is reserved on standard MSHC controllers) for
 110         * optionally bypassing the HOLD register for command and data. The
 111         * HOLD register should be bypassed in case there is no phase shift
 112         * applied on CMD/DATA that is sent to the card.
 113         */
 114        if (SDMMC_CLKSEL_GET_DRV_WD3(mci_readl(host, CLKSEL)))
 115                *cmdr |= SDMMC_CMD_USE_HOLD_REG;
 116}
 117
 118static void dw_mci_exynos_set_ios(struct dw_mci *host, struct mmc_ios *ios)
 119{
 120        struct dw_mci_exynos_priv_data *priv = host->priv;
 121
 122        if (ios->timing == MMC_TIMING_UHS_DDR50)
 123                mci_writel(host, CLKSEL, priv->ddr_timing);
 124        else
 125                mci_writel(host, CLKSEL, priv->sdr_timing);
 126}
 127
 128static int dw_mci_exynos_parse_dt(struct dw_mci *host)
 129{
 130        struct dw_mci_exynos_priv_data *priv = host->priv;
 131        struct device_node *np = host->dev->of_node;
 132        u32 timing[2];
 133        u32 div = 0;
 134        int ret;
 135
 136        of_property_read_u32(np, "samsung,dw-mshc-ciu-div", &div);
 137        priv->ciu_div = div;
 138
 139        ret = of_property_read_u32_array(np,
 140                        "samsung,dw-mshc-sdr-timing", timing, 2);
 141        if (ret)
 142                return ret;
 143
 144        priv->sdr_timing = SDMMC_CLKSEL_TIMING(timing[0], timing[1], div);
 145
 146        ret = of_property_read_u32_array(np,
 147                        "samsung,dw-mshc-ddr-timing", timing, 2);
 148        if (ret)
 149                return ret;
 150
 151        priv->ddr_timing = SDMMC_CLKSEL_TIMING(timing[0], timing[1], div);
 152        return 0;
 153}
 154
 155/* Common capabilities of Exynos4/Exynos5 SoC */
 156static unsigned long exynos_dwmmc_caps[4] = {
 157        MMC_CAP_UHS_DDR50 | MMC_CAP_1_8V_DDR |
 158                MMC_CAP_8_BIT_DATA | MMC_CAP_CMD23,
 159        MMC_CAP_CMD23,
 160        MMC_CAP_CMD23,
 161        MMC_CAP_CMD23,
 162};
 163
 164static const struct dw_mci_drv_data exynos_drv_data = {
 165        .caps                   = exynos_dwmmc_caps,
 166        .init                   = dw_mci_exynos_priv_init,
 167        .setup_clock            = dw_mci_exynos_setup_clock,
 168        .prepare_command        = dw_mci_exynos_prepare_command,
 169        .set_ios                = dw_mci_exynos_set_ios,
 170        .parse_dt               = dw_mci_exynos_parse_dt,
 171};
 172
 173static const struct of_device_id dw_mci_exynos_match[] = {
 174        { .compatible = "samsung,exynos4412-dw-mshc",
 175                        .data = &exynos_drv_data, },
 176        { .compatible = "samsung,exynos5250-dw-mshc",
 177                        .data = &exynos_drv_data, },
 178        {},
 179};
 180MODULE_DEVICE_TABLE(of, dw_mci_exynos_match);
 181
 182static int dw_mci_exynos_probe(struct platform_device *pdev)
 183{
 184        const struct dw_mci_drv_data *drv_data;
 185        const struct of_device_id *match;
 186
 187        match = of_match_node(dw_mci_exynos_match, pdev->dev.of_node);
 188        drv_data = match->data;
 189        return dw_mci_pltfm_register(pdev, drv_data);
 190}
 191
 192static struct platform_driver dw_mci_exynos_pltfm_driver = {
 193        .probe          = dw_mci_exynos_probe,
 194        .remove         = __exit_p(dw_mci_pltfm_remove),
 195        .driver         = {
 196                .name           = "dwmmc_exynos",
 197                .of_match_table = dw_mci_exynos_match,
 198                .pm             = &dw_mci_pltfm_pmops,
 199        },
 200};
 201
 202module_platform_driver(dw_mci_exynos_pltfm_driver);
 203
 204MODULE_DESCRIPTION("Samsung Specific DW-MSHC Driver Extension");
 205MODULE_AUTHOR("Thomas Abraham <thomas.ab@samsung.com");
 206MODULE_LICENSE("GPL v2");
 207MODULE_ALIAS("platform:dwmmc-exynos");
 208