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
stm32_pwr_reg_is_ready(struct regulator_dev * rdev)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
stm32_pwr_reg_is_enabled(struct regulator_dev * rdev)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
stm32_pwr_reg_enable(struct regulator_dev * rdev)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
stm32_pwr_reg_disable(struct regulator_dev * rdev)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
stm32_pwr_regulator_probe(struct platform_device * pdev)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