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
17 struct bq257xx_reg_data {
18 struct regulator_dev *bq257xx_reg;
19 struct gpio_desc *otg_en_gpio;
20 struct regulator_desc desc;
21 };
22
bq25703_vbus_get_cur_limit(struct regulator_dev * rdev)23 static int bq25703_vbus_get_cur_limit(struct regulator_dev *rdev)
24 {
25 struct regmap *regmap = rdev_get_regmap(rdev);
26 int ret;
27 unsigned int reg;
28
29 ret = regmap_read(regmap, BQ25703_OTG_CURRENT, ®);
30 if (ret)
31 return ret;
32 return FIELD_GET(BQ25703_OTG_CUR_MASK, reg) * BQ25703_OTG_CUR_STEP_UA;
33 }
34
35 /*
36 * Check if the minimum current and maximum current requested are
37 * sane values, then set the register accordingly.
38 */
bq25703_vbus_set_cur_limit(struct regulator_dev * rdev,int min_uA,int max_uA)39 static int bq25703_vbus_set_cur_limit(struct regulator_dev *rdev,
40 int min_uA, int max_uA)
41 {
42 struct regmap *regmap = rdev_get_regmap(rdev);
43 unsigned int reg;
44
45 if ((min_uA > BQ25703_OTG_CUR_MAX_UA) || (max_uA < 0))
46 return -EINVAL;
47
48 reg = (max_uA / BQ25703_OTG_CUR_STEP_UA);
49
50 /* Catch rounding errors since our step is 50000uA. */
51 if ((reg * BQ25703_OTG_CUR_STEP_UA) < min_uA)
52 return -EINVAL;
53
54 return regmap_write(regmap, BQ25703_OTG_CURRENT,
55 FIELD_PREP(BQ25703_OTG_CUR_MASK, reg));
56 }
57
bq25703_vbus_enable(struct regulator_dev * rdev)58 static int bq25703_vbus_enable(struct regulator_dev *rdev)
59 {
60 struct bq257xx_reg_data *pdata = rdev_get_drvdata(rdev);
61
62 if (pdata->otg_en_gpio)
63 gpiod_set_value_cansleep(pdata->otg_en_gpio, 1);
64 return regulator_enable_regmap(rdev);
65 }
66
bq25703_vbus_disable(struct regulator_dev * rdev)67 static int bq25703_vbus_disable(struct regulator_dev *rdev)
68 {
69 struct bq257xx_reg_data *pdata = rdev_get_drvdata(rdev);
70
71 if (pdata->otg_en_gpio)
72 gpiod_set_value_cansleep(pdata->otg_en_gpio, 0);
73 return regulator_disable_regmap(rdev);
74 }
75
76 static const struct regulator_ops bq25703_vbus_ops = {
77 .enable = bq25703_vbus_enable,
78 .disable = bq25703_vbus_disable,
79 .is_enabled = regulator_is_enabled_regmap,
80 .list_voltage = regulator_list_voltage_linear,
81 .get_voltage_sel = regulator_get_voltage_sel_regmap,
82 .set_voltage_sel = regulator_set_voltage_sel_regmap,
83 .get_current_limit = bq25703_vbus_get_cur_limit,
84 .set_current_limit = bq25703_vbus_set_cur_limit,
85 };
86
87 static const struct regulator_desc bq25703_vbus_desc = {
88 .name = "vbus",
89 .of_match = of_match_ptr("vbus"),
90 .regulators_node = of_match_ptr("regulators"),
91 .type = REGULATOR_VOLTAGE,
92 .owner = THIS_MODULE,
93 .ops = &bq25703_vbus_ops,
94 .min_uV = BQ25703_OTG_VOLT_MIN_UV,
95 .uV_step = BQ25703_OTG_VOLT_STEP_UV,
96 .n_voltages = BQ25703_OTG_VOLT_NUM_VOLT,
97 .enable_mask = BQ25703_EN_OTG_MASK,
98 .enable_reg = BQ25703_CHARGE_OPTION_3,
99 .enable_val = BQ25703_EN_OTG_MASK,
100 .disable_val = 0,
101 .vsel_reg = BQ25703_OTG_VOLT,
102 .vsel_mask = BQ25703_OTG_VOLT_MASK,
103 };
104
105 /* Get optional GPIO for OTG regulator enable. */
bq257xx_reg_dt_parse_gpio(struct platform_device * pdev)106 static void bq257xx_reg_dt_parse_gpio(struct platform_device *pdev)
107 {
108 struct device_node *child, *subchild;
109 struct bq257xx_reg_data *pdata = platform_get_drvdata(pdev);
110
111 child = of_get_child_by_name(pdev->dev.of_node,
112 pdata->desc.regulators_node);
113 if (!child)
114 return;
115
116 subchild = of_get_child_by_name(child, pdata->desc.of_match);
117 of_node_put(child);
118 if (!subchild)
119 return;
120
121 pdata->otg_en_gpio = devm_fwnode_gpiod_get_index(&pdev->dev,
122 of_fwnode_handle(subchild),
123 "enable", 0,
124 GPIOD_OUT_LOW,
125 pdata->desc.of_match);
126
127 of_node_put(subchild);
128
129 if (IS_ERR(pdata->otg_en_gpio)) {
130 if (PTR_ERR(pdata->otg_en_gpio) == -ENOENT) {
131 /* No GPIO, will only use register writes for OTG */
132 pdata->otg_en_gpio = NULL;
133 return;
134 }
135
136 dev_err(&pdev->dev, "Error getting enable gpio: %ld\n",
137 PTR_ERR(pdata->otg_en_gpio));
138 return;
139 }
140 }
141
bq257xx_regulator_probe(struct platform_device * pdev)142 static int bq257xx_regulator_probe(struct platform_device *pdev)
143 {
144 struct device *dev = &pdev->dev;
145 struct bq257xx_reg_data *pdata;
146 struct device_node *np = dev->of_node;
147 struct regulator_config cfg = {};
148
149 device_set_of_node_from_dev(&pdev->dev, pdev->dev.parent);
150
151 pdata = devm_kzalloc(&pdev->dev, sizeof(struct bq257xx_reg_data), GFP_KERNEL);
152 if (!pdata)
153 return -ENOMEM;
154
155 pdata->desc = bq25703_vbus_desc;
156
157 platform_set_drvdata(pdev, pdata);
158 bq257xx_reg_dt_parse_gpio(pdev);
159
160 cfg.dev = &pdev->dev;
161 cfg.driver_data = pdata;
162 cfg.of_node = np;
163 cfg.regmap = dev_get_regmap(pdev->dev.parent, NULL);
164 if (!cfg.regmap)
165 return -ENODEV;
166
167 pdata->bq257xx_reg = devm_regulator_register(dev, &pdata->desc, &cfg);
168 if (IS_ERR(pdata->bq257xx_reg)) {
169 return dev_err_probe(&pdev->dev, PTR_ERR(pdata->bq257xx_reg),
170 "error registering bq257xx regulator");
171 }
172
173 return 0;
174 }
175
176 static struct platform_driver bq257xx_reg_driver = {
177 .driver = {
178 .name = "bq257xx-regulator",
179 },
180 .probe = bq257xx_regulator_probe,
181 };
182
183 module_platform_driver(bq257xx_reg_driver);
184
185 MODULE_DESCRIPTION("bq257xx regulator driver");
186 MODULE_AUTHOR("Chris Morgan <macromorgan@hotmail.com>");
187 MODULE_LICENSE("GPL");
188