1// SPDX-License-Identifier: GPL-2.0+
2
3#include <linux/gpio/consumer.h>
4#include <linux/i2c.h>
5#include <linux/kernel.h>
6#include <linux/module.h>
7#include <linux/of.h>
8#include <linux/regmap.h>
9#include <linux/regulator/driver.h>
10
11#define RT4801_REG_VOP 0x00
12#define RT4801_REG_VON 0x01
13#define RT4801_REG_APPS 0x03
14
15#define VOUT_MASK 0x1F
16
17#define MIN_UV 4000000
18#define STEP_UV 100000
19#define MAX_UV 6000000
20#define N_VOLTAGES ((MAX_UV - MIN_UV) / STEP_UV + 1)
21
22#define DSV_OUT_POS 0
23#define DSV_OUT_NEG 1
24#define DSV_OUT_MAX 2
25
26#define DSVP_ENABLE BIT(0)
27#define DSVN_ENABLE BIT(1)
28#define DSVALL_ENABLE (DSVP_ENABLE | DSVN_ENABLE)
29
30struct rt4801_priv {
31 struct device *dev;
32 struct gpio_desc *enable_gpios[DSV_OUT_MAX];
33 unsigned int enable_flag;
34 unsigned int volt_sel[DSV_OUT_MAX];
35};
36
37static int rt4801_of_parse_cb(struct device_node *np,
38 const struct regulator_desc *desc,
39 struct regulator_config *config)
40{
41 struct rt4801_priv *priv = config->driver_data;
42 int id = desc->id;
43
44 if (priv->enable_gpios[id]) {
45 dev_warn(priv->dev, "duplicated enable-gpios property\n");
46 return 0;
47 }
48 priv->enable_gpios[id] = devm_fwnode_gpiod_get_index(dev: priv->dev,
49 of_fwnode_handle(np),
50 con_id: "enable", index: 0,
51 flags: GPIOD_OUT_HIGH,
52 label: "rt4801");
53 if (IS_ERR(ptr: priv->enable_gpios[id]))
54 priv->enable_gpios[id] = NULL;
55
56 return 0;
57}
58
59static int rt4801_set_voltage_sel(struct regulator_dev *rdev, unsigned int selector)
60{
61 struct rt4801_priv *priv = rdev_get_drvdata(rdev);
62 int id = rdev_get_id(rdev), ret;
63
64 if (priv->enable_flag & BIT(id)) {
65 ret = regulator_set_voltage_sel_regmap(rdev, sel: selector);
66 if (ret)
67 return ret;
68 }
69
70 priv->volt_sel[id] = selector;
71 return 0;
72}
73
74static int rt4801_get_voltage_sel(struct regulator_dev *rdev)
75{
76 struct rt4801_priv *priv = rdev_get_drvdata(rdev);
77 int id = rdev_get_id(rdev);
78
79 if (priv->enable_flag & BIT(id))
80 return regulator_get_voltage_sel_regmap(rdev);
81
82 return priv->volt_sel[id];
83}
84
85static int rt4801_enable(struct regulator_dev *rdev)
86{
87 struct rt4801_priv *priv = rdev_get_drvdata(rdev);
88 int id = rdev_get_id(rdev), ret;
89
90 if (!priv->enable_gpios[id]) {
91 dev_warn(&rdev->dev, "no dedicated gpio can control\n");
92 goto bypass_gpio;
93 }
94
95 gpiod_set_value(desc: priv->enable_gpios[id], value: 1);
96
97bypass_gpio:
98 ret = regmap_write(map: rdev->regmap, reg: rdev->desc->vsel_reg, val: priv->volt_sel[id]);
99 if (ret)
100 return ret;
101
102 priv->enable_flag |= BIT(id);
103 return 0;
104}
105
106static int rt4801_disable(struct regulator_dev *rdev)
107{
108 struct rt4801_priv *priv = rdev_get_drvdata(rdev);
109 int id = rdev_get_id(rdev);
110
111 if (!priv->enable_gpios[id]) {
112 dev_warn(&rdev->dev, "no dedicated gpio can control\n");
113 goto bypass_gpio;
114 }
115
116 gpiod_set_value(desc: priv->enable_gpios[id], value: 0);
117
118bypass_gpio:
119 priv->enable_flag &= ~BIT(id);
120 return 0;
121}
122
123static int rt4801_is_enabled(struct regulator_dev *rdev)
124{
125 struct rt4801_priv *priv = rdev_get_drvdata(rdev);
126 int id = rdev_get_id(rdev);
127
128 return !!(priv->enable_flag & BIT(id));
129}
130
131static const struct regulator_ops rt4801_regulator_ops = {
132 .list_voltage = regulator_list_voltage_linear,
133 .set_voltage_sel = rt4801_set_voltage_sel,
134 .get_voltage_sel = rt4801_get_voltage_sel,
135 .enable = rt4801_enable,
136 .disable = rt4801_disable,
137 .is_enabled = rt4801_is_enabled,
138};
139
140static const struct regulator_desc rt4801_regulator_descs[] = {
141 {
142 .name = "DSVP",
143 .ops = &rt4801_regulator_ops,
144 .of_match = of_match_ptr("DSVP"),
145 .of_parse_cb = rt4801_of_parse_cb,
146 .type = REGULATOR_VOLTAGE,
147 .id = DSV_OUT_POS,
148 .min_uV = MIN_UV,
149 .uV_step = STEP_UV,
150 .n_voltages = N_VOLTAGES,
151 .owner = THIS_MODULE,
152 .vsel_reg = RT4801_REG_VOP,
153 .vsel_mask = VOUT_MASK,
154 },
155 {
156 .name = "DSVN",
157 .ops = &rt4801_regulator_ops,
158 .of_match = of_match_ptr("DSVN"),
159 .of_parse_cb = rt4801_of_parse_cb,
160 .type = REGULATOR_VOLTAGE,
161 .id = DSV_OUT_NEG,
162 .min_uV = MIN_UV,
163 .uV_step = STEP_UV,
164 .n_voltages = N_VOLTAGES,
165 .owner = THIS_MODULE,
166 .vsel_reg = RT4801_REG_VON,
167 .vsel_mask = VOUT_MASK,
168 },
169};
170
171static const struct regmap_config rt4801_regmap_config = {
172 .reg_bits = 8,
173 .val_bits = 8,
174 .max_register = RT4801_REG_APPS,
175};
176
177static int rt4801_probe(struct i2c_client *i2c)
178{
179 struct rt4801_priv *priv;
180 struct regmap *regmap;
181 int i;
182
183 priv = devm_kzalloc(dev: &i2c->dev, size: sizeof(*priv), GFP_KERNEL);
184 if (!priv)
185 return -ENOMEM;
186
187 priv->dev = &i2c->dev;
188 /* bootloader will on, driver only reconfigure enable to all output high */
189 priv->enable_flag = DSVALL_ENABLE;
190
191 regmap = devm_regmap_init_i2c(i2c, &rt4801_regmap_config);
192 if (IS_ERR(ptr: regmap)) {
193 dev_err(&i2c->dev, "Failed to init regmap\n");
194 return PTR_ERR(ptr: regmap);
195 }
196
197 for (i = 0; i < DSV_OUT_MAX; i++) {
198 priv->enable_gpios[i] = devm_gpiod_get_index_optional(dev: &i2c->dev,
199 con_id: "enable",
200 index: i,
201 flags: GPIOD_OUT_HIGH);
202 if (IS_ERR(ptr: priv->enable_gpios[i])) {
203 dev_err(&i2c->dev, "Failed to get gpios\n");
204 return PTR_ERR(ptr: priv->enable_gpios[i]);
205 }
206 }
207
208 for (i = 0; i < DSV_OUT_MAX; i++) {
209 const struct regulator_desc *desc = rt4801_regulator_descs + i;
210 struct regulator_config config = { .dev = &i2c->dev, .driver_data = priv,
211 .regmap = regmap, };
212 struct regulator_dev *rdev;
213 unsigned int val;
214 int ret;
215
216 /* initialize volt_sel variable */
217 ret = regmap_read(map: regmap, reg: desc->vsel_reg, val: &val);
218 if (ret)
219 return ret;
220
221 priv->volt_sel[i] = val & desc->vsel_mask;
222
223 rdev = devm_regulator_register(dev: &i2c->dev, regulator_desc: desc, config: &config);
224 if (IS_ERR(ptr: rdev)) {
225 dev_err(&i2c->dev, "Failed to register [%d] regulator\n", i);
226 return PTR_ERR(ptr: rdev);
227 }
228 }
229
230 return 0;
231}
232
233static const struct of_device_id __maybe_unused rt4801_of_id[] = {
234 { .compatible = "richtek,rt4801", },
235 { },
236};
237MODULE_DEVICE_TABLE(of, rt4801_of_id);
238
239static struct i2c_driver rt4801_driver = {
240 .driver = {
241 .name = "rt4801",
242 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
243 .of_match_table = of_match_ptr(rt4801_of_id),
244 },
245 .probe = rt4801_probe,
246};
247module_i2c_driver(rt4801_driver);
248
249MODULE_AUTHOR("ChiYuan Hwang <cy_huang@richtek.com>");
250MODULE_DESCRIPTION("Richtek RT4801 Display Bias Driver");
251MODULE_LICENSE("GPL v2");
252

source code of linux/drivers/regulator/rt4801-regulator.c