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"); 187