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 */
27enum {
28	PWR_REG11,
29	PWR_REG18,
30	PWR_USB33,
31	STM32PWR_REG_NUM_REGS
32};
33
34static 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
40struct stm32_pwr_reg {
41	void __iomem *base;
42	u32 ready_mask;
43};
44
45static 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
55static 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
65static 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
84static 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
103static 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
123static 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
129static 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
167static const struct of_device_id __maybe_unused stm32_pwr_of_match[] = {
168	{ .compatible = "st,stm32mp1,pwr-reg", },
169	{},
170};
171MODULE_DEVICE_TABLE(of, stm32_pwr_of_match);
172
173static 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};
181module_platform_driver(stm32_pwr_driver);
182
183MODULE_DESCRIPTION("STM32MP1 PWR voltage regulator driver");
184MODULE_AUTHOR("Pascal Paillet <p.paillet@st.com>");
185