drivers/regulator/stw481x-vmmc.c

   1 /*
   2  * Regulator driver for STw4810/STw4811 VMMC regulator.
   3  *
   4  * Copyright (C) 2013 ST-Ericsson SA
   5  * Written on behalf of Linaro for ST-Ericsson
   6  *
   7  * Author: Linus Walleij <linus.walleij@linaro.org>
   8  *
   9  * License terms: GNU General Public License (GPL) version 2
  10  */
  11
  12 #include <linux/err.h>
  13 #include <linux/init.h>
  14 #include <linux/mfd/stw481x.h>
  15 #include <linux/module.h>
  16 #include <linux/platform_device.h>
  17 #include <linux/regulator/driver.h>
  18 #include <linux/regulator/of_regulator.h>
  19
  20 static const unsigned int stw481x_vmmc_voltages[] = {
  21         1800000,
  22         1800000,
  23         2850000,
  24         3000000,
  25         1850000,
  26         2600000,
  27         2700000,
  28         3300000,
  29 };
  30
  31 static struct regulator_ops stw481x_vmmc_ops = {
  32         .list_voltage = regulator_list_voltage_table,
  33         .enable      = regulator_enable_regmap,
  34         .disable     = regulator_disable_regmap,
  35         .is_enabled  = regulator_is_enabled_regmap,
  36         .get_voltage_sel = regulator_get_voltage_sel_regmap,
  37         .set_voltage_sel = regulator_set_voltage_sel_regmap,
  38 };
  39
  40 static struct regulator_desc vmmc_regulator = {
  41         .name = "VMMC",
  42         .id   = 0,
  43         .ops  = &stw481x_vmmc_ops,
  44         .type = REGULATOR_VOLTAGE,
  45         .owner = THIS_MODULE,
  46         .n_voltages = ARRAY_SIZE(stw481x_vmmc_voltages),
  47         .volt_table = stw481x_vmmc_voltages,
  48         .enable_time = 200, /* FIXME: look this up */
  49         .enable_reg = STW_CONF1,
  50         .enable_mask = STW_CONF1_PDN_VMMC | STW_CONF1_MMC_LS_STATUS,
  51         .enable_val = STW_CONF1_PDN_VMMC,
  52         .vsel_reg = STW_CONF1,
  53         .vsel_mask = STW_CONF1_VMMC_MASK,
  54 };
  55
  56 static int stw481x_vmmc_regulator_probe(struct platform_device *pdev)
  57 {
  58         struct stw481x *stw481x = dev_get_platdata(&pdev->dev);
  59         struct regulator_config config = { };
  60         struct regulator_dev *rdev;
  61         int ret;
  62
  63         /* First disable the external VMMC if it's active */
  64         ret = regmap_update_bits(stw481x->map, STW_CONF2,
  65                                  STW_CONF2_VMMC_EXT, 0);
  66         if (ret) {
  67                 dev_err(&pdev->dev, "could not disable external VMMC\n");
  68                 return ret;
  69         }
  70
  71         /* Register VMMC regulator */
  72         config.dev = &pdev->dev;
  73         config.driver_data = stw481x;
  74         config.regmap = stw481x->map;
  75         config.of_node = pdev->dev.of_node;
  76         config.init_data = of_get_regulator_init_data(&pdev->dev,
  77                                                       pdev->dev.of_node,
  78                                                       &vmmc_regulator);
  79
  80         rdev = devm_regulator_register(&pdev->dev, &vmmc_regulator, &config);
  81         if (IS_ERR(rdev)) {
  82                 dev_err(&pdev->dev,
  83                         "error initializing STw481x VMMC regulator\n");
  84                 return PTR_ERR(rdev);
  85         }
  86
  87         dev_info(&pdev->dev, "initialized STw481x VMMC regulator\n");
  88         return 0;
  89 }
  90
  91 static const struct of_device_id stw481x_vmmc_match[] = {
  92         { .compatible = "st,stw481x-vmmc", },
  93         {},
  94 };
  95
  96 static struct platform_driver stw481x_vmmc_regulator_driver = {
  97         .driver = {
  98                 .name  = "stw481x-vmmc-regulator",
  99                 .of_match_table = stw481x_vmmc_match,
 100         },
 101         .probe = stw481x_vmmc_regulator_probe,
 102 };
 103
 104 module_platform_driver(stw481x_vmmc_regulator_driver);