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