340 lines
8.8 KiB
C
340 lines
8.8 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* max8952.c - Voltage and current regulation for the Maxim 8952
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*
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* Copyright (C) 2010 Samsung Electronics
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* MyungJoo Ham <myungjoo.ham@samsung.com>
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*/
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/i2c.h>
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#include <linux/err.h>
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#include <linux/platform_device.h>
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#include <linux/regulator/driver.h>
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#include <linux/regulator/max8952.h>
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#include <linux/gpio/consumer.h>
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#include <linux/io.h>
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#include <linux/of.h>
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#include <linux/regulator/of_regulator.h>
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#include <linux/slab.h>
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/* Registers */
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enum {
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MAX8952_REG_MODE0,
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MAX8952_REG_MODE1,
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MAX8952_REG_MODE2,
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MAX8952_REG_MODE3,
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MAX8952_REG_CONTROL,
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MAX8952_REG_SYNC,
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MAX8952_REG_RAMP,
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MAX8952_REG_CHIP_ID1,
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MAX8952_REG_CHIP_ID2,
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};
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struct max8952_data {
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struct i2c_client *client;
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struct max8952_platform_data *pdata;
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struct gpio_desc *vid0_gpiod;
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struct gpio_desc *vid1_gpiod;
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bool vid0;
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bool vid1;
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};
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static int max8952_read_reg(struct max8952_data *max8952, u8 reg)
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{
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int ret = i2c_smbus_read_byte_data(max8952->client, reg);
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if (ret > 0)
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ret &= 0xff;
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return ret;
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}
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static int max8952_write_reg(struct max8952_data *max8952,
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u8 reg, u8 value)
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{
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return i2c_smbus_write_byte_data(max8952->client, reg, value);
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}
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static int max8952_list_voltage(struct regulator_dev *rdev,
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unsigned int selector)
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{
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struct max8952_data *max8952 = rdev_get_drvdata(rdev);
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if (rdev_get_id(rdev) != 0)
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return -EINVAL;
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return (max8952->pdata->dvs_mode[selector] * 10 + 770) * 1000;
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}
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static int max8952_get_voltage_sel(struct regulator_dev *rdev)
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{
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struct max8952_data *max8952 = rdev_get_drvdata(rdev);
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u8 vid = 0;
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if (max8952->vid0)
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vid += 1;
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if (max8952->vid1)
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vid += 2;
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return vid;
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}
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static int max8952_set_voltage_sel(struct regulator_dev *rdev,
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unsigned selector)
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{
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struct max8952_data *max8952 = rdev_get_drvdata(rdev);
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if (!max8952->vid0_gpiod || !max8952->vid1_gpiod) {
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/* DVS not supported */
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return -EPERM;
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}
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max8952->vid0 = selector & 0x1;
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max8952->vid1 = (selector >> 1) & 0x1;
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gpiod_set_value(max8952->vid0_gpiod, max8952->vid0);
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gpiod_set_value(max8952->vid1_gpiod, max8952->vid1);
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return 0;
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}
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static const struct regulator_ops max8952_ops = {
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.list_voltage = max8952_list_voltage,
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.get_voltage_sel = max8952_get_voltage_sel,
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.set_voltage_sel = max8952_set_voltage_sel,
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};
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static const struct regulator_desc regulator = {
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.name = "MAX8952_VOUT",
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.id = 0,
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.n_voltages = MAX8952_NUM_DVS_MODE,
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.ops = &max8952_ops,
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.type = REGULATOR_VOLTAGE,
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.owner = THIS_MODULE,
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};
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#ifdef CONFIG_OF
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static const struct of_device_id max8952_dt_match[] = {
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{ .compatible = "maxim,max8952" },
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{},
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};
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MODULE_DEVICE_TABLE(of, max8952_dt_match);
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static struct max8952_platform_data *max8952_parse_dt(struct device *dev)
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{
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struct max8952_platform_data *pd;
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struct device_node *np = dev->of_node;
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int ret;
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int i;
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pd = devm_kzalloc(dev, sizeof(*pd), GFP_KERNEL);
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if (!pd)
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return NULL;
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if (of_property_read_u32(np, "max8952,default-mode", &pd->default_mode))
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dev_warn(dev, "Default mode not specified, assuming 0\n");
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ret = of_property_read_u32_array(np, "max8952,dvs-mode-microvolt",
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pd->dvs_mode, ARRAY_SIZE(pd->dvs_mode));
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if (ret) {
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dev_err(dev, "max8952,dvs-mode-microvolt property not specified");
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return NULL;
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}
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for (i = 0; i < ARRAY_SIZE(pd->dvs_mode); ++i) {
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if (pd->dvs_mode[i] < 770000 || pd->dvs_mode[i] > 1400000) {
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dev_err(dev, "DVS voltage %d out of range\n", i);
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return NULL;
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}
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pd->dvs_mode[i] = (pd->dvs_mode[i] - 770000) / 10000;
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}
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if (of_property_read_u32(np, "max8952,sync-freq", &pd->sync_freq))
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dev_warn(dev, "max8952,sync-freq property not specified, defaulting to 26MHz\n");
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if (of_property_read_u32(np, "max8952,ramp-speed", &pd->ramp_speed))
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dev_warn(dev, "max8952,ramp-speed property not specified, defaulting to 32mV/us\n");
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pd->reg_data = of_get_regulator_init_data(dev, np, ®ulator);
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if (!pd->reg_data) {
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dev_err(dev, "Failed to parse regulator init data\n");
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return NULL;
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}
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return pd;
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}
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#else
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static struct max8952_platform_data *max8952_parse_dt(struct device *dev)
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{
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return NULL;
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}
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#endif
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static int max8952_pmic_probe(struct i2c_client *client)
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{
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struct i2c_adapter *adapter = client->adapter;
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struct max8952_platform_data *pdata = dev_get_platdata(&client->dev);
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struct regulator_config config = { };
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struct max8952_data *max8952;
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struct regulator_dev *rdev;
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struct gpio_desc *gpiod;
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enum gpiod_flags gflags;
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int ret = 0;
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if (client->dev.of_node)
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pdata = max8952_parse_dt(&client->dev);
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if (!pdata) {
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dev_err(&client->dev, "Require the platform data\n");
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return -EINVAL;
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}
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if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
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return -EIO;
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max8952 = devm_kzalloc(&client->dev, sizeof(struct max8952_data),
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GFP_KERNEL);
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if (!max8952)
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return -ENOMEM;
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max8952->client = client;
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max8952->pdata = pdata;
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config.dev = &client->dev;
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config.init_data = pdata->reg_data;
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config.driver_data = max8952;
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config.of_node = client->dev.of_node;
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if (pdata->reg_data->constraints.boot_on)
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gflags = GPIOD_OUT_HIGH;
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else
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gflags = GPIOD_OUT_LOW;
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gflags |= GPIOD_FLAGS_BIT_NONEXCLUSIVE;
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/*
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* Do not use devm* here: the regulator core takes over the
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* lifecycle management of the GPIO descriptor.
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*/
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gpiod = gpiod_get_optional(&client->dev,
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"max8952,en",
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gflags);
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if (IS_ERR(gpiod))
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return PTR_ERR(gpiod);
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if (gpiod)
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config.ena_gpiod = gpiod;
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rdev = devm_regulator_register(&client->dev, ®ulator, &config);
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if (IS_ERR(rdev)) {
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ret = PTR_ERR(rdev);
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dev_err(&client->dev, "regulator init failed (%d)\n", ret);
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return ret;
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}
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max8952->vid0 = pdata->default_mode & 0x1;
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max8952->vid1 = (pdata->default_mode >> 1) & 0x1;
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/* Fetch vid0 and vid1 GPIOs if available */
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gflags = max8952->vid0 ? GPIOD_OUT_HIGH : GPIOD_OUT_LOW;
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max8952->vid0_gpiod = devm_gpiod_get_index_optional(&client->dev,
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"max8952,vid",
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0, gflags);
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if (IS_ERR(max8952->vid0_gpiod))
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return PTR_ERR(max8952->vid0_gpiod);
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gflags = max8952->vid1 ? GPIOD_OUT_HIGH : GPIOD_OUT_LOW;
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max8952->vid1_gpiod = devm_gpiod_get_index_optional(&client->dev,
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"max8952,vid",
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1, gflags);
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if (IS_ERR(max8952->vid1_gpiod))
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return PTR_ERR(max8952->vid1_gpiod);
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/* If either VID GPIO is missing just disable this */
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if (!max8952->vid0_gpiod || !max8952->vid1_gpiod) {
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dev_warn(&client->dev, "VID0/1 gpio invalid: "
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"DVS not available.\n");
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max8952->vid0 = 0;
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max8952->vid1 = 0;
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/* Make sure if we have any descriptors they get set to low */
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if (max8952->vid0_gpiod)
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gpiod_set_value(max8952->vid0_gpiod, 0);
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if (max8952->vid1_gpiod)
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gpiod_set_value(max8952->vid1_gpiod, 0);
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/* Disable Pulldown of EN only */
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max8952_write_reg(max8952, MAX8952_REG_CONTROL, 0x60);
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dev_err(&client->dev, "DVS modes disabled because VID0 and VID1"
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" do not have proper controls.\n");
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} else {
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/*
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* Disable Pulldown on EN, VID0, VID1 to reduce
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* leakage current of MAX8952 assuming that MAX8952
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* is turned on (EN==1). Note that without having VID0/1
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* properly connected, turning pulldown off can be
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* problematic. Thus, turn this off only when they are
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* controllable by GPIO.
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*/
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max8952_write_reg(max8952, MAX8952_REG_CONTROL, 0x0);
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}
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max8952_write_reg(max8952, MAX8952_REG_MODE0,
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(max8952_read_reg(max8952,
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MAX8952_REG_MODE0) & 0xC0) |
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(pdata->dvs_mode[0] & 0x3F));
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max8952_write_reg(max8952, MAX8952_REG_MODE1,
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(max8952_read_reg(max8952,
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MAX8952_REG_MODE1) & 0xC0) |
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(pdata->dvs_mode[1] & 0x3F));
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max8952_write_reg(max8952, MAX8952_REG_MODE2,
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(max8952_read_reg(max8952,
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MAX8952_REG_MODE2) & 0xC0) |
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(pdata->dvs_mode[2] & 0x3F));
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max8952_write_reg(max8952, MAX8952_REG_MODE3,
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(max8952_read_reg(max8952,
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MAX8952_REG_MODE3) & 0xC0) |
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(pdata->dvs_mode[3] & 0x3F));
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max8952_write_reg(max8952, MAX8952_REG_SYNC,
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(max8952_read_reg(max8952, MAX8952_REG_SYNC) & 0x3F) |
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((pdata->sync_freq & 0x3) << 6));
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max8952_write_reg(max8952, MAX8952_REG_RAMP,
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(max8952_read_reg(max8952, MAX8952_REG_RAMP) & 0x1F) |
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((pdata->ramp_speed & 0x7) << 5));
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i2c_set_clientdata(client, max8952);
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return 0;
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}
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static const struct i2c_device_id max8952_ids[] = {
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{ "max8952", 0 },
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{ },
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};
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MODULE_DEVICE_TABLE(i2c, max8952_ids);
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static struct i2c_driver max8952_pmic_driver = {
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.probe = max8952_pmic_probe,
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.driver = {
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.name = "max8952",
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.probe_type = PROBE_PREFER_ASYNCHRONOUS,
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.of_match_table = of_match_ptr(max8952_dt_match),
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},
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.id_table = max8952_ids,
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};
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static int __init max8952_pmic_init(void)
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{
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return i2c_add_driver(&max8952_pmic_driver);
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}
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subsys_initcall(max8952_pmic_init);
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static void __exit max8952_pmic_exit(void)
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{
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i2c_del_driver(&max8952_pmic_driver);
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}
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module_exit(max8952_pmic_exit);
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MODULE_DESCRIPTION("MAXIM 8952 voltage regulator driver");
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MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
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MODULE_LICENSE("GPL");
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