drivers/mmc/host/dw_mmc-socfpga.c

   1 /*
   2  * Altera SoCFPGA Specific Extensions for Synopsys DW Multimedia Card Interface
   3  * driver
   4  *
   5  *  Copyright (C) 2012, Samsung Electronics Co., Ltd.
   6  *  Copyright (C) 2013 Altera Corporation
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * Taken from dw_mmc-exynos.c
  14  */
  15 #include <linux/clk.h>
  16 #include <linux/mfd/syscon.h>
  17 #include <linux/mmc/host.h>
  18 #include <linux/mmc/dw_mmc.h>
  19 #include <linux/module.h>
  20 #include <linux/of.h>
  21 #include <linux/platform_device.h>
  22 #include <linux/regmap.h>
  23
  24 #include "dw_mmc.h"
  25 #include "dw_mmc-pltfm.h"
  26
  27 #define SYSMGR_SDMMCGRP_CTRL_OFFSET             0x108
  28 #define DRV_CLK_PHASE_SHIFT_SEL_MASK    0x7
  29 #define SYSMGR_SDMMC_CTRL_SET(smplsel, drvsel)          \
  30         ((((smplsel) & 0x7) << 3) | (((drvsel) & 0x7) << 0))
  31
  32 /* SOCFPGA implementation specific driver private data */
  33 struct dw_mci_socfpga_priv_data {
  34         u8      ciu_div; /* card interface unit divisor */
  35         u32     hs_timing; /* bitmask for CIU clock phase shift */
  36         struct regmap   *sysreg; /* regmap for system manager register */
  37 };
  38
  39 static int dw_mci_socfpga_priv_init(struct dw_mci *host)
  40 {
  41         struct dw_mci_socfpga_priv_data *priv;
  42
  43         priv = devm_kzalloc(host->dev, sizeof(*priv), GFP_KERNEL);
  44         if (!priv) {
  45                 dev_err(host->dev, "mem alloc failed for private data\n");
  46                 return -ENOMEM;
  47         }
  48
  49         priv->sysreg = syscon_regmap_lookup_by_compatible("altr,sys-mgr");
  50         if (IS_ERR(priv->sysreg)) {
  51                 dev_err(host->dev, "regmap for altr,sys-mgr lookup failed.\n");
  52                 return PTR_ERR(priv->sysreg);
  53         }
  54         host->priv = priv;
  55
  56         return 0;
  57 }
  58
  59 static int dw_mci_socfpga_setup_clock(struct dw_mci *host)
  60 {
  61         struct dw_mci_socfpga_priv_data *priv = host->priv;
  62
  63         clk_disable_unprepare(host->ciu_clk);
  64         regmap_write(priv->sysreg, SYSMGR_SDMMCGRP_CTRL_OFFSET,
  65                 priv->hs_timing);
  66         clk_prepare_enable(host->ciu_clk);
  67
  68         host->bus_hz /= (priv->ciu_div + 1);
  69         return 0;
  70 }
  71
  72 static void dw_mci_socfpga_prepare_command(struct dw_mci *host, u32 *cmdr)
  73 {
  74         struct dw_mci_socfpga_priv_data *priv = host->priv;
  75
  76         if (priv->hs_timing & DRV_CLK_PHASE_SHIFT_SEL_MASK)
  77                 *cmdr |= SDMMC_CMD_USE_HOLD_REG;
  78 }
  79
  80 static int dw_mci_socfpga_parse_dt(struct dw_mci *host)
  81 {
  82         struct dw_mci_socfpga_priv_data *priv = host->priv;
  83         struct device_node *np = host->dev->of_node;
  84         u32 timing[2];
  85         u32 div = 0;
  86         int ret;
  87
  88         ret = of_property_read_u32(np, "altr,dw-mshc-ciu-div", &div);
  89         if (ret)
  90                 dev_info(host->dev, "No dw-mshc-ciu-div specified, assuming 1");
  91         priv->ciu_div = div;
  92
  93         ret = of_property_read_u32_array(np,
  94                         "altr,dw-mshc-sdr-timing", timing, 2);
  95         if (ret)
  96                 return ret;
  97
  98         priv->hs_timing = SYSMGR_SDMMC_CTRL_SET(timing[0], timing[1]);
  99         return 0;
 100 }
 101
 102 static const struct dw_mci_drv_data socfpga_drv_data = {
 103         .init                   = dw_mci_socfpga_priv_init,
 104         .setup_clock            = dw_mci_socfpga_setup_clock,
 105         .prepare_command        = dw_mci_socfpga_prepare_command,
 106         .parse_dt               = dw_mci_socfpga_parse_dt,
 107 };
 108
 109 static const struct of_device_id dw_mci_socfpga_match[] = {
 110         { .compatible = "altr,socfpga-dw-mshc",
 111                         .data = &socfpga_drv_data, },
 112         {},
 113 };
 114 MODULE_DEVICE_TABLE(of, dw_mci_socfpga_match);
 115
 116 int dw_mci_socfpga_probe(struct platform_device *pdev)
 117 {
 118         const struct dw_mci_drv_data *drv_data;
 119         const struct of_device_id *match;
 120
 121         match = of_match_node(dw_mci_socfpga_match, pdev->dev.of_node);
 122         drv_data = match->data;
 123         return dw_mci_pltfm_register(pdev, drv_data);
 124 }
 125
 126 static struct platform_driver dw_mci_socfpga_pltfm_driver = {
 127         .probe          = dw_mci_socfpga_probe,
 128         .remove         = __exit_p(dw_mci_pltfm_remove),
 129         .driver         = {
 130                 .name           = "dwmmc_socfpga",
 131                 .of_match_table = of_match_ptr(dw_mci_socfpga_match),
 132                 .pm             = &dw_mci_pltfm_pmops,
 133         },
 134 };
 135
 136 module_platform_driver(dw_mci_socfpga_pltfm_driver);
 137
 138 MODULE_DESCRIPTION("Altera SOCFPGA Specific DW-MSHC Driver Extension");
 139 MODULE_LICENSE("GPL v2");
 140 MODULE_ALIAS("platform:dwmmc-socfpga");