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(priv->dev,
 49							     of_fwnode_handle(np),
 50							     "enable", 0,
 51							     GPIOD_OUT_HIGH,
 52							     "rt4801");
 53	if (IS_ERR(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, 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(priv->enable_gpios[id], 1);
 96
 97bypass_gpio:
 98	ret = regmap_write(rdev->regmap, rdev->desc->vsel_reg, 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(priv->enable_gpios[id], 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(&i2c->dev, 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(regmap)) {
193		dev_err(&i2c->dev, "Failed to init regmap\n");
194		return PTR_ERR(regmap);
195	}
196
197	for (i = 0; i < DSV_OUT_MAX; i++) {
198		priv->enable_gpios[i] = devm_gpiod_get_index_optional(&i2c->dev,
199								      "enable",
200								      i,
201								      GPIOD_OUT_HIGH);
202		if (IS_ERR(priv->enable_gpios[i])) {
203			dev_err(&i2c->dev, "Failed to get gpios\n");
204			return PTR_ERR(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(regmap, desc->vsel_reg, &val);
218		if (ret)
219			return ret;
220
221		priv->volt_sel[i] = val & desc->vsel_mask;
222
223		rdev = devm_regulator_register(&i2c->dev, desc, &config);
224		if (IS_ERR(rdev)) {
225			dev_err(&i2c->dev, "Failed to register [%d] regulator\n", i);
226			return PTR_ERR(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");