1// SPDX-License-Identifier: GPL-2.0
2/*
3 * BQ257XX Battery Charger Driver
4 * Copyright (C) 2025 Chris Morgan <macromorgan@hotmail.com>
5 */
6
7#include <linux/bitfield.h>
8#include <linux/err.h>
9#include <linux/gpio/consumer.h>
10#include <linux/mfd/bq257xx.h>
11#include <linux/of.h>
12#include <linux/platform_device.h>
13#include <linux/regmap.h>
14#include <linux/regulator/driver.h>
15#include <linux/regulator/of_regulator.h>
16
17struct bq257xx_reg_data {
18 struct bq257xx_device *bq;
19 struct regulator_dev *bq257xx_reg;
20 struct gpio_desc *otg_en_gpio;
21 struct regulator_desc desc;
22};
23
24static int bq25703_vbus_get_cur_limit(struct regulator_dev *rdev)
25{
26 struct bq257xx_reg_data *pdata = rdev_get_drvdata(rdev);
27 int ret;
28 unsigned int reg;
29
30 ret = regmap_read(map: pdata->bq->regmap, BQ25703_OTG_CURRENT, val: &reg);
31 if (ret)
32 return ret;
33 return FIELD_GET(BQ25703_OTG_CUR_MASK, reg) * BQ25703_OTG_CUR_STEP_UA;
34}
35
36/*
37 * Check if the minimum current and maximum current requested are
38 * sane values, then set the register accordingly.
39 */
40static int bq25703_vbus_set_cur_limit(struct regulator_dev *rdev,
41 int min_uA, int max_uA)
42{
43 struct bq257xx_reg_data *pdata = rdev_get_drvdata(rdev);
44 unsigned int reg;
45
46 if ((min_uA > BQ25703_OTG_CUR_MAX_UA) || (max_uA < 0))
47 return -EINVAL;
48
49 reg = (max_uA / BQ25703_OTG_CUR_STEP_UA);
50
51 /* Catch rounding errors since our step is 50000uA. */
52 if ((reg * BQ25703_OTG_CUR_STEP_UA) < min_uA)
53 return -EINVAL;
54
55 return regmap_write(map: pdata->bq->regmap, BQ25703_OTG_CURRENT,
56 FIELD_PREP(BQ25703_OTG_CUR_MASK, reg));
57}
58
59static int bq25703_vbus_enable(struct regulator_dev *rdev)
60{
61 struct bq257xx_reg_data *pdata = rdev_get_drvdata(rdev);
62
63 if (pdata->otg_en_gpio)
64 gpiod_set_value_cansleep(desc: pdata->otg_en_gpio, value: 1);
65 return regulator_enable_regmap(rdev);
66}
67
68static int bq25703_vbus_disable(struct regulator_dev *rdev)
69{
70 struct bq257xx_reg_data *pdata = rdev_get_drvdata(rdev);
71
72 if (pdata->otg_en_gpio)
73 gpiod_set_value_cansleep(desc: pdata->otg_en_gpio, value: 0);
74 return regulator_disable_regmap(rdev);
75}
76
77static const struct regulator_ops bq25703_vbus_ops = {
78 .enable = bq25703_vbus_enable,
79 .disable = bq25703_vbus_disable,
80 .is_enabled = regulator_is_enabled_regmap,
81 .list_voltage = regulator_list_voltage_linear,
82 .get_voltage_sel = regulator_get_voltage_sel_regmap,
83 .set_voltage_sel = regulator_set_voltage_sel_regmap,
84 .get_current_limit = bq25703_vbus_get_cur_limit,
85 .set_current_limit = bq25703_vbus_set_cur_limit,
86};
87
88static const struct regulator_desc bq25703_vbus_desc = {
89 .name = "vbus",
90 .of_match = of_match_ptr("vbus"),
91 .regulators_node = of_match_ptr("regulators"),
92 .type = REGULATOR_VOLTAGE,
93 .owner = THIS_MODULE,
94 .ops = &bq25703_vbus_ops,
95 .min_uV = BQ25703_OTG_VOLT_MIN_UV,
96 .uV_step = BQ25703_OTG_VOLT_STEP_UV,
97 .n_voltages = BQ25703_OTG_VOLT_NUM_VOLT,
98 .enable_mask = BQ25703_EN_OTG_MASK,
99 .enable_reg = BQ25703_CHARGE_OPTION_3,
100 .enable_val = BQ25703_EN_OTG_MASK,
101 .disable_val = 0,
102 .vsel_reg = BQ25703_OTG_VOLT,
103 .vsel_mask = BQ25703_OTG_VOLT_MASK,
104};
105
106/* Get optional GPIO for OTG regulator enable. */
107static void bq257xx_reg_dt_parse_gpio(struct platform_device *pdev)
108{
109 struct device_node *child, *subchild;
110 struct bq257xx_reg_data *pdata = platform_get_drvdata(pdev);
111
112 child = of_get_child_by_name(node: pdev->dev.of_node,
113 name: pdata->desc.regulators_node);
114 if (!child)
115 return;
116
117 subchild = of_get_child_by_name(node: child, name: pdata->desc.of_match);
118 if (!subchild)
119 return;
120
121 of_node_put(node: child);
122
123 pdata->otg_en_gpio = devm_fwnode_gpiod_get_index(dev: &pdev->dev,
124 of_fwnode_handle(subchild),
125 con_id: "enable", index: 0,
126 flags: GPIOD_OUT_LOW,
127 label: pdata->desc.of_match);
128
129 of_node_put(node: subchild);
130
131 if (IS_ERR(ptr: pdata->otg_en_gpio)) {
132 dev_err(&pdev->dev, "Error getting enable gpio: %ld\n",
133 PTR_ERR(pdata->otg_en_gpio));
134 return;
135 }
136}
137
138static int bq257xx_regulator_probe(struct platform_device *pdev)
139{
140 struct device *dev = &pdev->dev;
141 struct bq257xx_device *bq = dev_get_drvdata(dev: pdev->dev.parent);
142 struct bq257xx_reg_data *pdata;
143 struct device_node *np = dev->of_node;
144 struct regulator_config cfg = {};
145
146 pdev->dev.of_node = pdev->dev.parent->of_node;
147 pdev->dev.of_node_reused = true;
148
149 pdata = devm_kzalloc(dev: &pdev->dev, size: sizeof(struct bq257xx_reg_data), GFP_KERNEL);
150 if (!pdata)
151 return -ENOMEM;
152
153 pdata->bq = bq;
154 pdata->desc = bq25703_vbus_desc;
155
156 platform_set_drvdata(pdev, data: pdata);
157 bq257xx_reg_dt_parse_gpio(pdev);
158
159 cfg.dev = &pdev->dev;
160 cfg.driver_data = pdata;
161 cfg.of_node = np;
162 cfg.regmap = dev_get_regmap(dev: pdev->dev.parent, NULL);
163 if (!cfg.regmap)
164 return -ENODEV;
165
166 pdata->bq257xx_reg = devm_regulator_register(dev, regulator_desc: &pdata->desc, config: &cfg);
167 if (IS_ERR(ptr: pdata->bq257xx_reg)) {
168 return dev_err_probe(dev: &pdev->dev, err: PTR_ERR(ptr: pdata->bq257xx_reg),
169 fmt: "error registering bq257xx regulator");
170 }
171
172 return 0;
173}
174
175static struct platform_driver bq257xx_reg_driver = {
176 .driver = {
177 .name = "bq257xx-regulator",
178 },
179 .probe = bq257xx_regulator_probe,
180};
181
182module_platform_driver(bq257xx_reg_driver);
183
184MODULE_DESCRIPTION("bq257xx regulator driver");
185MODULE_AUTHOR("Chris Morgan <macromorgan@hotmail.com>");
186MODULE_LICENSE("GPL");
187

source code of linux/drivers/regulator/bq257xx-regulator.c