drivers/regulator/stm32-pwr.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 // Copyright (C) STMicroelectronics 2019
   3 // Authors: Gabriel Fernandez <gabriel.fernandez@st.com>
   4 //          Pascal Paillet <p.paillet@st.com>.
   5
   6 #include <linux/io.h>
   7 #include <linux/iopoll.h>
   8 #include <linux/module.h>
   9 #include <linux/of_address.h>
  10 #include <linux/of_device.h>
  11 #include <linux/platform_device.h>
  12 #include <linux/regulator/driver.h>
  13 #include <linux/regulator/of_regulator.h>
  14
  15 /*
  16  * Registers description
  17  */
  18 #define REG_PWR_CR3 0x0C
  19
  20 #define USB_3_3_EN BIT(24)
  21 #define USB_3_3_RDY BIT(26)
  22 #define REG_1_8_EN BIT(28)
  23 #define REG_1_8_RDY BIT(29)
  24 #define REG_1_1_EN BIT(30)
  25 #define REG_1_1_RDY BIT(31)
  26
  27 /* list of supported regulators */
  28 enum {
  29         PWR_REG11,
  30         PWR_REG18,
  31         PWR_USB33,
  32         STM32PWR_REG_NUM_REGS
  33 };
  34
  35 static u32 ready_mask_table[STM32PWR_REG_NUM_REGS] = {
  36         [PWR_REG11] = REG_1_1_RDY,
  37         [PWR_REG18] = REG_1_8_RDY,
  38         [PWR_USB33] = USB_3_3_RDY,
  39 };
  40
  41 struct stm32_pwr_reg {
  42         void __iomem *base;
  43         const struct regulator_desc *desc;
  44         u32 ready_mask;
  45 };
  46
  47 static int stm32_pwr_reg_is_ready(struct regulator_dev *rdev)
  48 {
  49         struct stm32_pwr_reg *priv = rdev_get_drvdata(rdev);
  50         u32 val;
  51
  52         val = readl_relaxed(priv->base + REG_PWR_CR3);
  53
  54         return (val & priv->ready_mask);
  55 }
  56
  57 static int stm32_pwr_reg_is_enabled(struct regulator_dev *rdev)
  58 {
  59         struct stm32_pwr_reg *priv = rdev_get_drvdata(rdev);
  60         u32 val;
  61
  62         val = readl_relaxed(priv->base + REG_PWR_CR3);
  63
  64         return (val & priv->desc->enable_mask);
  65 }
  66
  67 static int stm32_pwr_reg_enable(struct regulator_dev *rdev)
  68 {
  69         struct stm32_pwr_reg *priv = rdev_get_drvdata(rdev);
  70         int ret;
  71         u32 val;
  72
  73         val = readl_relaxed(priv->base + REG_PWR_CR3);
  74         val |= priv->desc->enable_mask;
  75         writel_relaxed(val, priv->base + REG_PWR_CR3);
  76
  77         /* use an arbitrary timeout of 20ms */
  78         ret = readx_poll_timeout(stm32_pwr_reg_is_ready, rdev, val, val,
  79                                  100, 20 * 1000);
  80         if (ret)
  81                 dev_err(&rdev->dev, "regulator enable timed out!\n");
  82
  83         return ret;
  84 }
  85
  86 static int stm32_pwr_reg_disable(struct regulator_dev *rdev)
  87 {
  88         struct stm32_pwr_reg *priv = rdev_get_drvdata(rdev);
  89         int ret;
  90         u32 val;
  91
  92         val = readl_relaxed(priv->base + REG_PWR_CR3);
  93         val &= ~priv->desc->enable_mask;
  94         writel_relaxed(val, priv->base + REG_PWR_CR3);
  95
  96         /* use an arbitrary timeout of 20ms */
  97         ret = readx_poll_timeout(stm32_pwr_reg_is_ready, rdev, val, !val,
  98                                  100, 20 * 1000);
  99         if (ret)
 100                 dev_err(&rdev->dev, "regulator disable timed out!\n");
 101
 102         return ret;
 103 }
 104
 105 static const struct regulator_ops stm32_pwr_reg_ops = {
 106         .list_voltage   = regulator_list_voltage_linear,
 107         .enable         = stm32_pwr_reg_enable,
 108         .disable        = stm32_pwr_reg_disable,
 109         .is_enabled     = stm32_pwr_reg_is_enabled,
 110 };
 111
 112 #define PWR_REG(_id, _name, _volt, _en, _supply) \
 113         [_id] = { \
 114                 .id = _id, \
 115                 .name = _name, \
 116                 .of_match = of_match_ptr(_name), \
 117                 .n_voltages = 1, \
 118                 .type = REGULATOR_VOLTAGE, \
 119                 .min_uV = _volt, \
 120                 .fixed_uV = _volt, \
 121                 .ops = &stm32_pwr_reg_ops, \
 122                 .enable_mask = _en, \
 123                 .owner = THIS_MODULE, \
 124                 .supply_name = _supply, \
 125         } \
 126
 127 static const struct regulator_desc stm32_pwr_desc[] = {
 128         PWR_REG(PWR_REG11, "reg11", 1100000, REG_1_1_EN, "vdd"),
 129         PWR_REG(PWR_REG18, "reg18", 1800000, REG_1_8_EN, "vdd"),
 130         PWR_REG(PWR_USB33, "usb33", 3300000, USB_3_3_EN, "vdd_3v3_usbfs"),
 131 };
 132
 133 static int stm32_pwr_regulator_probe(struct platform_device *pdev)
 134 {
 135         struct device_node *np = pdev->dev.of_node;
 136         struct stm32_pwr_reg *priv;
 137         void __iomem *base;
 138         struct regulator_dev *rdev;
 139         struct regulator_config config = { };
 140         int i, ret = 0;
 141
 142         base = of_iomap(np, 0);
 143         if (IS_ERR(base)) {
 144                 dev_err(&pdev->dev, "Unable to map IO memory\n");
 145                 return PTR_ERR(base);
 146         }
 147
 148         config.dev = &pdev->dev;
 149
 150         for (i = 0; i < STM32PWR_REG_NUM_REGS; i++) {
 151                 priv = devm_kzalloc(&pdev->dev, sizeof(struct stm32_pwr_reg),
 152                                     GFP_KERNEL);
 153                 if (!priv)
 154                         return -ENOMEM;
 155                 priv->base = base;
 156                 priv->desc = &stm32_pwr_desc[i];
 157                 priv->ready_mask = ready_mask_table[i];
 158                 config.driver_data = priv;
 159
 160                 rdev = devm_regulator_register(&pdev->dev,
 161                                                &stm32_pwr_desc[i],
 162                                                &config);
 163                 if (IS_ERR(rdev)) {
 164                         ret = PTR_ERR(rdev);
 165                         dev_err(&pdev->dev,
 166                                 "Failed to register regulator: %d\n", ret);
 167                         break;
 168                 }
 169         }
 170         return ret;
 171 }
 172
 173 static const struct of_device_id stm32_pwr_of_match[] = {
 174         { .compatible = "st,stm32mp1,pwr-reg", },
 175         {},
 176 };
 177 MODULE_DEVICE_TABLE(of, stm32_pwr_of_match);
 178
 179 static struct platform_driver stm32_pwr_driver = {
 180         .probe = stm32_pwr_regulator_probe,
 181         .driver = {
 182                 .name  = "stm32-pwr-regulator",
 183                 .of_match_table = of_match_ptr(stm32_pwr_of_match),
 184         },
 185 };
 186 module_platform_driver(stm32_pwr_driver);
 187
 188 MODULE_DESCRIPTION("STM32MP1 PWR voltage regulator driver");
 189 MODULE_AUTHOR("Pascal Paillet <p.paillet@st.com>");
 190 MODULE_LICENSE("GPL v2");