bq257xx-regulator.c

  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(pdata->bq->regmap, BQ25703_OTG_CURRENT, &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(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(pdata->otg_en_gpio, 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(pdata->otg_en_gpio, 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(pdev->dev.of_node,
113				     pdata->desc.regulators_node);
114	if (!child)
115		return;
116
117	subchild = of_get_child_by_name(child, pdata->desc.of_match);
118	of_node_put(child);
119	if (!subchild)
120		return;
121
122	pdata->otg_en_gpio = devm_fwnode_gpiod_get_index(&pdev->dev,
123							 of_fwnode_handle(subchild),
124							 "enable", 0,
125							 GPIOD_OUT_LOW,
126							 pdata->desc.of_match);
127
128	of_node_put(subchild);
129
130	if (IS_ERR(pdata->otg_en_gpio)) {
131		dev_err(&pdev->dev, "Error getting enable gpio: %ld\n",
132			PTR_ERR(pdata->otg_en_gpio));
133		return;
134	}
135}
136
137static int bq257xx_regulator_probe(struct platform_device *pdev)
138{
139	struct device *dev = &pdev->dev;
140	struct bq257xx_device *bq = dev_get_drvdata(pdev->dev.parent);
141	struct bq257xx_reg_data *pdata;
142	struct device_node *np = dev->of_node;
143	struct regulator_config cfg = {};
144
145	pdev->dev.of_node = pdev->dev.parent->of_node;
146	pdev->dev.of_node_reused = true;
147
148	pdata = devm_kzalloc(&pdev->dev, sizeof(struct bq257xx_reg_data), GFP_KERNEL);
149	if (!pdata)
150		return -ENOMEM;
151
152	pdata->bq = bq;
153	pdata->desc = bq25703_vbus_desc;
154
155	platform_set_drvdata(pdev, pdata);
156	bq257xx_reg_dt_parse_gpio(pdev);
157
158	cfg.dev = &pdev->dev;
159	cfg.driver_data = pdata;
160	cfg.of_node = np;
161	cfg.regmap = dev_get_regmap(pdev->dev.parent, NULL);
162	if (!cfg.regmap)
163		return -ENODEV;
164
165	pdata->bq257xx_reg = devm_regulator_register(dev, &pdata->desc, &cfg);
166	if (IS_ERR(pdata->bq257xx_reg)) {
167		return dev_err_probe(&pdev->dev, PTR_ERR(pdata->bq257xx_reg),
168				     "error registering bq257xx regulator");
169	}
170
171	return 0;
172}
173
174static struct platform_driver bq257xx_reg_driver = {
175	.driver = {
176		.name = "bq257xx-regulator",
177	},
178	.probe = bq257xx_regulator_probe,
179};
180
181module_platform_driver(bq257xx_reg_driver);
182
183MODULE_DESCRIPTION("bq257xx regulator driver");
184MODULE_AUTHOR("Chris Morgan <macromorgan@hotmail.com>");
185MODULE_LICENSE("GPL");