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authorOndrej Jirman <megous@megous.com>2018-05-07 20:29:41 +0800
committerMark Brown <broonie@kernel.org>2018-05-09 18:25:06 +0900
commit8878302ebbc580d64f390c0acc509e5e8276598c (patch)
tree461c48fca9680fd04b88a0e8ca7e0d1cfa1c2077 /drivers/regulator/sy8106a-regulator.c
parent32aba834f2a9fe126ff5e624371113ac1defa06e (diff)
regulator: add support for SY8106A regulator
SY8106A is an I2C attached single output regulator made by Silergy Corp, which is used on several Allwinner H3/H5 SBCs to control the power supply of the ARM cores. Add a driver for it. Signed-off-by: Ondrej Jirman <megous@megous.com> [Icenowy: Change commit message, remove enable/disable code, add default ramp_delay, add comment for go bit, add code for fixed mode voltage] Signed-off-by: Icenowy Zheng <icenowy@aosc.io> Reviewed-by: Chen-Yu Tsai <wens@csie.org> Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/regulator/sy8106a-regulator.c')
-rw-r--r--drivers/regulator/sy8106a-regulator.c167
1 files changed, 167 insertions, 0 deletions
diff --git a/drivers/regulator/sy8106a-regulator.c b/drivers/regulator/sy8106a-regulator.c
new file mode 100644
index 000000000000..65fbd1f0b612
--- /dev/null
+++ b/drivers/regulator/sy8106a-regulator.c
@@ -0,0 +1,167 @@
+// SPDX-License-Identifier: GPL-2.0+
+//
+// sy8106a-regulator.c - Regulator device driver for SY8106A
+//
+// Copyright (C) 2016 Ondřej Jirman <megous@megous.com>
+// Copyright (c) 2017-2018 Icenowy Zheng <icenowy@aosc.io>
+
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/of_regulator.h>
+
+#define SY8106A_REG_VOUT1_SEL 0x01
+#define SY8106A_REG_VOUT_COM 0x02
+#define SY8106A_REG_VOUT1_SEL_MASK 0x7f
+#define SY8106A_DISABLE_REG BIT(0)
+/*
+ * The I2C controlled voltage will only work when this bit is set; otherwise
+ * it will behave like a fixed regulator.
+ */
+#define SY8106A_GO_BIT BIT(7)
+
+struct sy8106a {
+ struct regulator_dev *rdev;
+ struct regmap *regmap;
+ u32 fixed_voltage;
+};
+
+static const struct regmap_config sy8106a_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 8,
+};
+
+static const struct regulator_ops sy8106a_ops = {
+ .set_voltage_sel = regulator_set_voltage_sel_regmap,
+ .set_voltage_time_sel = regulator_set_voltage_time_sel,
+ .get_voltage_sel = regulator_get_voltage_sel_regmap,
+ .list_voltage = regulator_list_voltage_linear,
+ /* Enabling/disabling the regulator is not yet implemented */
+};
+
+/* Default limits measured in millivolts */
+#define SY8106A_MIN_MV 680
+#define SY8106A_MAX_MV 1950
+#define SY8106A_STEP_MV 10
+
+static const struct regulator_desc sy8106a_reg = {
+ .name = "SY8106A",
+ .id = 0,
+ .ops = &sy8106a_ops,
+ .type = REGULATOR_VOLTAGE,
+ .n_voltages = ((SY8106A_MAX_MV - SY8106A_MIN_MV) / SY8106A_STEP_MV) + 1,
+ .min_uV = (SY8106A_MIN_MV * 1000),
+ .uV_step = (SY8106A_STEP_MV * 1000),
+ .vsel_reg = SY8106A_REG_VOUT1_SEL,
+ .vsel_mask = SY8106A_REG_VOUT1_SEL_MASK,
+ /*
+ * This ramp_delay is a conservative default value which works on
+ * H3/H5 boards VDD-CPUX situations.
+ */
+ .ramp_delay = 200,
+ .owner = THIS_MODULE,
+};
+
+/*
+ * I2C driver interface functions
+ */
+static int sy8106a_i2c_probe(struct i2c_client *i2c,
+ const struct i2c_device_id *id)
+{
+ struct sy8106a *chip;
+ struct device *dev = &i2c->dev;
+ struct regulator_dev *rdev = NULL;
+ struct regulator_config config = { };
+ unsigned int reg, vsel;
+ int error;
+
+ chip = devm_kzalloc(&i2c->dev, sizeof(struct sy8106a), GFP_KERNEL);
+ if (!chip)
+ return -ENOMEM;
+
+ error = of_property_read_u32(dev->of_node, "silergy,fixed-microvolt",
+ &chip->fixed_voltage);
+ if (error)
+ return error;
+
+ if (chip->fixed_voltage < SY8106A_MIN_MV * 1000 ||
+ chip->fixed_voltage > SY8106A_MAX_MV * 1000)
+ return -EINVAL;
+
+ chip->regmap = devm_regmap_init_i2c(i2c, &sy8106a_regmap_config);
+ if (IS_ERR(chip->regmap)) {
+ error = PTR_ERR(chip->regmap);
+ dev_err(dev, "Failed to allocate register map: %d\n", error);
+ return error;
+ }
+
+ config.dev = &i2c->dev;
+ config.regmap = chip->regmap;
+ config.driver_data = chip;
+
+ config.of_node = dev->of_node;
+ config.init_data = of_get_regulator_init_data(dev, dev->of_node,
+ &sy8106a_reg);
+
+ if (!config.init_data)
+ return -ENOMEM;
+
+ /* Ensure GO_BIT is enabled when probing */
+ error = regmap_read(chip->regmap, SY8106A_REG_VOUT1_SEL, &reg);
+ if (error)
+ return error;
+
+ if (!(reg & SY8106A_GO_BIT)) {
+ vsel = (chip->fixed_voltage / 1000 - SY8106A_MIN_MV) /
+ SY8106A_STEP_MV;
+
+ error = regmap_write(chip->regmap, SY8106A_REG_VOUT1_SEL,
+ vsel | SY8106A_GO_BIT);
+ if (error)
+ return error;
+ }
+
+ /* Probe regulator */
+ rdev = devm_regulator_register(&i2c->dev, &sy8106a_reg, &config);
+ if (IS_ERR(rdev)) {
+ error = PTR_ERR(rdev);
+ dev_err(&i2c->dev, "Failed to register SY8106A regulator: %d\n", error);
+ return error;
+ }
+
+ chip->rdev = rdev;
+
+ i2c_set_clientdata(i2c, chip);
+
+ return 0;
+}
+
+static const struct of_device_id sy8106a_i2c_of_match[] = {
+ { .compatible = "silergy,sy8106a" },
+ { },
+};
+MODULE_DEVICE_TABLE(of, sy8106a_i2c_of_match);
+
+static const struct i2c_device_id sy8106a_i2c_id[] = {
+ { "sy8106a", 0 },
+ { },
+};
+MODULE_DEVICE_TABLE(i2c, sy8106a_i2c_id);
+
+static struct i2c_driver sy8106a_regulator_driver = {
+ .driver = {
+ .name = "sy8106a",
+ .of_match_table = of_match_ptr(sy8106a_i2c_of_match),
+ },
+ .probe = sy8106a_i2c_probe,
+ .id_table = sy8106a_i2c_id,
+};
+
+module_i2c_driver(sy8106a_regulator_driver);
+
+MODULE_AUTHOR("Ondřej Jirman <megous@megous.com>");
+MODULE_AUTHOR("Icenowy Zheng <icenowy@aosc.io>");
+MODULE_DESCRIPTION("Regulator device driver for Silergy SY8106A");
+MODULE_LICENSE("GPL");