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         u32 ready_mask;
  44 };
  45
  46 static int stm32_pwr_reg_is_ready(struct regulator_dev *rdev)
  47 {
  48         struct stm32_pwr_reg *priv = rdev_get_drvdata(rdev);
  49         u32 val;
  50
  51         val = readl_relaxed(priv->base + REG_PWR_CR3);
  52
  53         return (val & priv->ready_mask);
  54 }
  55
  56 static int stm32_pwr_reg_is_enabled(struct regulator_dev *rdev)
  57 {
  58         struct stm32_pwr_reg *priv = rdev_get_drvdata(rdev);
  59         u32 val;
  60
  61         val = readl_relaxed(priv->base + REG_PWR_CR3);
  62
  63         return (val & rdev->desc->enable_mask);
  64 }
  65
  66 static int stm32_pwr_reg_enable(struct regulator_dev *rdev)
  67 {
  68         struct stm32_pwr_reg *priv = rdev_get_drvdata(rdev);
  69         int ret;
  70         u32 val;
  71
  72         val = readl_relaxed(priv->base + REG_PWR_CR3);
  73         val |= rdev->desc->enable_mask;
  74         writel_relaxed(val, priv->base + REG_PWR_CR3);
  75
  76         /* use an arbitrary timeout of 20ms */
  77         ret = readx_poll_timeout(stm32_pwr_reg_is_ready, rdev, val, val,
  78                                  100, 20 * 1000);
  79         if (ret)
  80                 dev_err(&rdev->dev, "regulator enable timed out!\n");
  81
  82         return ret;
  83 }
  84
  85 static int stm32_pwr_reg_disable(struct regulator_dev *rdev)
  86 {
  87         struct stm32_pwr_reg *priv = rdev_get_drvdata(rdev);
  88         int ret;
  89         u32 val;
  90
  91         val = readl_relaxed(priv->base + REG_PWR_CR3);
  92         val &= ~rdev->desc->enable_mask;
  93         writel_relaxed(val, priv->base + REG_PWR_CR3);
  94
  95         /* use an arbitrary timeout of 20ms */
  96         ret = readx_poll_timeout(stm32_pwr_reg_is_ready, rdev, val, !val,
  97                                  100, 20 * 1000);
  98         if (ret)
  99                 dev_err(&rdev->dev, "regulator disable timed out!\n");
 100
 101         return ret;
 102 }
 103
 104 static const struct regulator_ops stm32_pwr_reg_ops = {
 105         .enable         = stm32_pwr_reg_enable,
 106         .disable        = stm32_pwr_reg_disable,
 107         .is_enabled     = stm32_pwr_reg_is_enabled,
 108 };
 109
 110 #define PWR_REG(_id, _name, _volt, _en, _supply) \
 111         [_id] = { \
 112                 .id = _id, \
 113                 .name = _name, \
 114                 .of_match = of_match_ptr(_name), \
 115                 .n_voltages = 1, \
 116                 .type = REGULATOR_VOLTAGE, \
 117                 .fixed_uV = _volt, \
 118                 .ops = &stm32_pwr_reg_ops, \
 119                 .enable_mask = _en, \
 120                 .owner = THIS_MODULE, \
 121                 .supply_name = _supply, \
 122         } \
 123
 124 static const struct regulator_desc stm32_pwr_desc[] = {
 125         PWR_REG(PWR_REG11, "reg11", 1100000, REG_1_1_EN, "vdd"),
 126         PWR_REG(PWR_REG18, "reg18", 1800000, REG_1_8_EN, "vdd"),
 127         PWR_REG(PWR_USB33, "usb33", 3300000, USB_3_3_EN, "vdd_3v3_usbfs"),
 128 };
 129
 130 static int stm32_pwr_regulator_probe(struct platform_device *pdev)
 131 {
 132         struct device_node *np = pdev->dev.of_node;
 133         struct stm32_pwr_reg *priv;
 134         void __iomem *base;
 135         struct regulator_dev *rdev;
 136         struct regulator_config config = { };
 137         int i, ret = 0;
 138
 139         base = of_iomap(np, 0);
 140         if (!base) {
 141                 dev_err(&pdev->dev, "Unable to map IO memory\n");
 142                 return -ENOMEM;
 143         }
 144
 145         config.dev = &pdev->dev;
 146
 147         for (i = 0; i < STM32PWR_REG_NUM_REGS; i++) {
 148                 priv = devm_kzalloc(&pdev->dev, sizeof(struct stm32_pwr_reg),
 149                                     GFP_KERNEL);
 150                 if (!priv)
 151                         return -ENOMEM;
 152                 priv->base = base;
 153                 priv->ready_mask = ready_mask_table[i];
 154                 config.driver_data = priv;
 155
 156                 rdev = devm_regulator_register(&pdev->dev,
 157                                                &stm32_pwr_desc[i],
 158                                                &config);
 159                 if (IS_ERR(rdev)) {
 160                         ret = PTR_ERR(rdev);
 161                         dev_err(&pdev->dev,
 162                                 "Failed to register regulator: %d\n", ret);
 163                         break;
 164                 }
 165         }
 166         return ret;
 167 }
 168
 169 static const struct of_device_id stm32_pwr_of_match[] = {
 170         { .compatible = "st,stm32mp1,pwr-reg", },
 171         {},
 172 };
 173 MODULE_DEVICE_TABLE(of, stm32_pwr_of_match);
 174
 175 static struct platform_driver stm32_pwr_driver = {
 176         .probe = stm32_pwr_regulator_probe,
 177         .driver = {
 178                 .name  = "stm32-pwr-regulator",
 179                 .of_match_table = of_match_ptr(stm32_pwr_of_match),
 180         },
 181 };
 182 module_platform_driver(stm32_pwr_driver);
 183
 184 MODULE_DESCRIPTION("STM32MP1 PWR voltage regulator driver");
 185 MODULE_AUTHOR("Pascal Paillet <p.paillet@st.com>");
 186 MODULE_LICENSE("GPL v2");