1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright (C) STMicroelectronics 2019
3 // Author(s): Fabrice Gasnier <fabrice.gasnier@st.com>.
4 
5 #include <linux/mfd/syscon.h>
6 #include <linux/module.h>
7 #include <linux/of_device.h>
8 #include <linux/platform_device.h>
9 #include <linux/regmap.h>
10 #include <linux/regulator/driver.h>
11 #include <linux/regulator/of_regulator.h>
12 
13 /* STM32H7 SYSCFG register */
14 #define STM32H7_SYSCFG_PMCR		0x04
15 #define STM32H7_SYSCFG_BOOSTE_MASK	BIT(8)
16 
17 /* STM32MP1 SYSCFG has set and clear registers */
18 #define STM32MP1_SYSCFG_PMCSETR		0x04
19 #define STM32MP1_SYSCFG_PMCCLRR		0x44
20 #define STM32MP1_SYSCFG_EN_BOOSTER_MASK	BIT(8)
21 
22 static const struct regulator_ops stm32h7_booster_ops = {
23 	.enable		= regulator_enable_regmap,
24 	.disable	= regulator_disable_regmap,
25 	.is_enabled	= regulator_is_enabled_regmap,
26 };
27 
28 static const struct regulator_desc stm32h7_booster_desc = {
29 	.name = "booster",
30 	.supply_name = "vdda",
31 	.n_voltages = 1,
32 	.type = REGULATOR_VOLTAGE,
33 	.fixed_uV = 3300000,
34 	.ramp_delay = 66000, /* up to 50us to stabilize */
35 	.ops = &stm32h7_booster_ops,
36 	.enable_reg = STM32H7_SYSCFG_PMCR,
37 	.enable_mask = STM32H7_SYSCFG_BOOSTE_MASK,
38 	.owner = THIS_MODULE,
39 };
40 
stm32mp1_booster_enable(struct regulator_dev * rdev)41 static int stm32mp1_booster_enable(struct regulator_dev *rdev)
42 {
43 	return regmap_write(rdev->regmap, STM32MP1_SYSCFG_PMCSETR,
44 			    STM32MP1_SYSCFG_EN_BOOSTER_MASK);
45 }
46 
stm32mp1_booster_disable(struct regulator_dev * rdev)47 static int stm32mp1_booster_disable(struct regulator_dev *rdev)
48 {
49 	return regmap_write(rdev->regmap, STM32MP1_SYSCFG_PMCCLRR,
50 			    STM32MP1_SYSCFG_EN_BOOSTER_MASK);
51 }
52 
53 static const struct regulator_ops stm32mp1_booster_ops = {
54 	.enable		= stm32mp1_booster_enable,
55 	.disable	= stm32mp1_booster_disable,
56 	.is_enabled	= regulator_is_enabled_regmap,
57 };
58 
59 static const struct regulator_desc stm32mp1_booster_desc = {
60 	.name = "booster",
61 	.supply_name = "vdda",
62 	.n_voltages = 1,
63 	.type = REGULATOR_VOLTAGE,
64 	.fixed_uV = 3300000,
65 	.ramp_delay = 66000,
66 	.ops = &stm32mp1_booster_ops,
67 	.enable_reg = STM32MP1_SYSCFG_PMCSETR,
68 	.enable_mask = STM32MP1_SYSCFG_EN_BOOSTER_MASK,
69 	.owner = THIS_MODULE,
70 };
71 
stm32_booster_probe(struct platform_device * pdev)72 static int stm32_booster_probe(struct platform_device *pdev)
73 {
74 	struct device *dev = &pdev->dev;
75 	struct device_node *np = pdev->dev.of_node;
76 	struct regulator_config config = { };
77 	const struct regulator_desc *desc;
78 	struct regulator_dev *rdev;
79 	struct regmap *regmap;
80 	int ret;
81 
82 	regmap = syscon_regmap_lookup_by_phandle(np, "st,syscfg");
83 	if (IS_ERR(regmap))
84 		return PTR_ERR(regmap);
85 
86 	desc = (const struct regulator_desc *)
87 		of_match_device(dev->driver->of_match_table, dev)->data;
88 
89 	config.regmap = regmap;
90 	config.dev = dev;
91 	config.of_node = np;
92 	config.init_data = of_get_regulator_init_data(dev, np, desc);
93 
94 	rdev = devm_regulator_register(dev, desc, &config);
95 	if (IS_ERR(rdev)) {
96 		ret = PTR_ERR(rdev);
97 		dev_err(dev, "register failed with error %d\n", ret);
98 		return ret;
99 	}
100 
101 	return 0;
102 }
103 
104 static const struct of_device_id __maybe_unused stm32_booster_of_match[] = {
105 	{
106 		.compatible = "st,stm32h7-booster",
107 		.data = (void *)&stm32h7_booster_desc
108 	}, {
109 		.compatible = "st,stm32mp1-booster",
110 		.data = (void *)&stm32mp1_booster_desc
111 	}, {
112 	},
113 };
114 MODULE_DEVICE_TABLE(of, stm32_booster_of_match);
115 
116 static struct platform_driver stm32_booster_driver = {
117 	.probe = stm32_booster_probe,
118 	.driver = {
119 		.name  = "stm32-booster",
120 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
121 		.of_match_table = of_match_ptr(stm32_booster_of_match),
122 	},
123 };
124 module_platform_driver(stm32_booster_driver);
125 
126 MODULE_LICENSE("GPL v2");
127 MODULE_AUTHOR("Fabrice Gasnier <fabrice.gasnier@st.com>");
128 MODULE_DESCRIPTION("STMicroelectronics STM32 booster regulator driver");
129 MODULE_ALIAS("platform:stm32-booster");
130