--- /dev/null
+/*
+ * max8952.c - Voltage and current regulation for the Maxim 8952
+ *
+ * Copyright (C) 2010 Samsung Electronics
+ * MyungJoo Ham <myungjoo.ham@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/i2c.h>
+#include <linux/err.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/max8952.h>
+#include <linux/gpio.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
+#include <linux/regulator/of_regulator.h>
+#include <linux/slab.h>
+
+/* Registers */
+enum {
+ MAX8952_REG_MODE0,
+ MAX8952_REG_MODE1,
+ MAX8952_REG_MODE2,
+ MAX8952_REG_MODE3,
+ MAX8952_REG_CONTROL,
+ MAX8952_REG_SYNC,
+ MAX8952_REG_RAMP,
+ MAX8952_REG_CHIP_ID1,
+ MAX8952_REG_CHIP_ID2,
+};
+
+struct max8952_data {
+ struct i2c_client *client;
+ struct max8952_platform_data *pdata;
+
+ bool vid0;
+ bool vid1;
+};
+
+static int max8952_read_reg(struct max8952_data *max8952, u8 reg)
+{
+ int ret = i2c_smbus_read_byte_data(max8952->client, reg);
+
+ if (ret > 0)
+ ret &= 0xff;
+
+ return ret;
+}
+
+static int max8952_write_reg(struct max8952_data *max8952,
+ u8 reg, u8 value)
+{
+ return i2c_smbus_write_byte_data(max8952->client, reg, value);
+}
+
+static int max8952_list_voltage(struct regulator_dev *rdev,
+ unsigned int selector)
+{
+ struct max8952_data *max8952 = rdev_get_drvdata(rdev);
+
+ if (rdev_get_id(rdev) != 0)
+ return -EINVAL;
+
+ return (max8952->pdata->dvs_mode[selector] * 10 + 770) * 1000;
+}
+
+static int max8952_get_voltage_sel(struct regulator_dev *rdev)
+{
+ struct max8952_data *max8952 = rdev_get_drvdata(rdev);
+ u8 vid = 0;
+
+ if (max8952->vid0)
+ vid += 1;
+ if (max8952->vid1)
+ vid += 2;
+
+ return vid;
+}
+
+static int max8952_set_voltage_sel(struct regulator_dev *rdev,
+ unsigned selector)
+{
+ struct max8952_data *max8952 = rdev_get_drvdata(rdev);
+
+ if (!gpio_is_valid(max8952->pdata->gpio_vid0) ||
+ !gpio_is_valid(max8952->pdata->gpio_vid1)) {
+ /* DVS not supported */
+ return -EPERM;
+ }
+
+ max8952->vid0 = selector & 0x1;
+ max8952->vid1 = (selector >> 1) & 0x1;
+ gpio_set_value(max8952->pdata->gpio_vid0, max8952->vid0);
+ gpio_set_value(max8952->pdata->gpio_vid1, max8952->vid1);
+
+ return 0;
+}
+
+static struct regulator_ops max8952_ops = {
+ .list_voltage = max8952_list_voltage,
+ .get_voltage_sel = max8952_get_voltage_sel,
+ .set_voltage_sel = max8952_set_voltage_sel,
+};
+
+static const struct regulator_desc regulator = {
+ .name = "MAX8952_VOUT",
+ .id = 0,
+ .n_voltages = MAX8952_NUM_DVS_MODE,
+ .ops = &max8952_ops,
+ .type = REGULATOR_VOLTAGE,
+ .owner = THIS_MODULE,
+};
+
+#ifdef CONFIG_OF
+static const struct of_device_id max8952_dt_match[] = {
+ { .compatible = "maxim,max8952" },
+ {},
+};
+MODULE_DEVICE_TABLE(of, max8952_dt_match);
+
+static struct max8952_platform_data *max8952_parse_dt(struct device *dev)
+{
+ struct max8952_platform_data *pd;
+ struct device_node *np = dev->of_node;
+ int ret;
+ int i;
+
+ pd = devm_kzalloc(dev, sizeof(*pd), GFP_KERNEL);
+ if (!pd)
+ return NULL;
+
+ pd->gpio_vid0 = of_get_named_gpio(np, "max8952,vid-gpios", 0);
+ pd->gpio_vid1 = of_get_named_gpio(np, "max8952,vid-gpios", 1);
+ pd->gpio_en = of_get_named_gpio(np, "max8952,en-gpio", 0);
+
+ if (of_property_read_u32(np, "max8952,default-mode", &pd->default_mode))
+ dev_warn(dev, "Default mode not specified, assuming 0\n");
+
+ ret = of_property_read_u32_array(np, "max8952,dvs-mode-microvolt",
+ pd->dvs_mode, ARRAY_SIZE(pd->dvs_mode));
+ if (ret) {
+ dev_err(dev, "max8952,dvs-mode-microvolt property not specified");
+ return NULL;
+ }
+
+ for (i = 0; i < ARRAY_SIZE(pd->dvs_mode); ++i) {
+ if (pd->dvs_mode[i] < 770000 || pd->dvs_mode[i] > 1400000) {
+ dev_err(dev, "DVS voltage %d out of range\n", i);
+ return NULL;
+ }
+ pd->dvs_mode[i] = (pd->dvs_mode[i] - 770000) / 10000;
+ }
+
+ if (of_property_read_u32(np, "max8952,sync-freq", &pd->sync_freq))
+ dev_warn(dev, "max8952,sync-freq property not specified, defaulting to 26MHz\n");
+
+ if (of_property_read_u32(np, "max8952,ramp-speed", &pd->ramp_speed))
+ dev_warn(dev, "max8952,ramp-speed property not specified, defaulting to 32mV/us\n");
+
+ pd->reg_data = of_get_regulator_init_data(dev, np, ®ulator);
+ if (!pd->reg_data) {
+ dev_err(dev, "Failed to parse regulator init data\n");
+ return NULL;
+ }
+
+ return pd;
+}
+#else
+static struct max8952_platform_data *max8952_parse_dt(struct device *dev)
+{
+ return NULL;
+}
+#endif
+
+static int max8952_pmic_probe(struct i2c_client *client,
+ const struct i2c_device_id *i2c_id)
+{
+ struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
+ struct max8952_platform_data *pdata = dev_get_platdata(&client->dev);
+ struct regulator_config config = { };
+ struct max8952_data *max8952;
+ struct regulator_dev *rdev;
+
+ int ret = 0, err = 0;
+
+ if (client->dev.of_node)
+ pdata = max8952_parse_dt(&client->dev);
+
+ if (!pdata) {
+ dev_err(&client->dev, "Require the platform data\n");
+ return -EINVAL;
+ }
+
+ if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
+ return -EIO;
+
+ max8952 = devm_kzalloc(&client->dev, sizeof(struct max8952_data),
+ GFP_KERNEL);
+ if (!max8952)
+ return -ENOMEM;
+
+ max8952->client = client;
+ max8952->pdata = pdata;
+
+ config.dev = &client->dev;
+ config.init_data = pdata->reg_data;
+ config.driver_data = max8952;
+ config.of_node = client->dev.of_node;
+
+ config.ena_gpio = pdata->gpio_en;
+ if (client->dev.of_node)
+ config.ena_gpio_initialized = true;
+ if (pdata->reg_data->constraints.boot_on)
+ config.ena_gpio_flags |= GPIOF_OUT_INIT_HIGH;
+
+ rdev = devm_regulator_register(&client->dev, ®ulator, &config);
+ if (IS_ERR(rdev)) {
+ ret = PTR_ERR(rdev);
+ dev_err(&client->dev, "regulator init failed (%d)\n", ret);
+ return ret;
+ }
+
+ max8952->vid0 = pdata->default_mode & 0x1;
+ max8952->vid1 = (pdata->default_mode >> 1) & 0x1;
+
+ if (gpio_is_valid(pdata->gpio_vid0) &&
+ gpio_is_valid(pdata->gpio_vid1)) {
+ unsigned long gpio_flags;
+
+ gpio_flags = max8952->vid0 ?
+ GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW;
+ if (devm_gpio_request_one(&client->dev, pdata->gpio_vid0,
+ gpio_flags, "MAX8952 VID0"))
+ err = 1;
+
+ gpio_flags = max8952->vid1 ?
+ GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW;
+ if (devm_gpio_request_one(&client->dev, pdata->gpio_vid1,
+ gpio_flags, "MAX8952 VID1"))
+ err = 2;
+ } else
+ err = 3;
+
+ if (err) {
+ dev_warn(&client->dev, "VID0/1 gpio invalid: "
+ "DVS not available.\n");
+ max8952->vid0 = 0;
+ max8952->vid1 = 0;
+ /* Mark invalid */
+ pdata->gpio_vid0 = -1;
+ pdata->gpio_vid1 = -1;
+
+ /* Disable Pulldown of EN only */
+ max8952_write_reg(max8952, MAX8952_REG_CONTROL, 0x60);
+
+ dev_err(&client->dev, "DVS modes disabled because VID0 and VID1"
+ " do not have proper controls.\n");
+ } else {
+ /*
+ * Disable Pulldown on EN, VID0, VID1 to reduce
+ * leakage current of MAX8952 assuming that MAX8952
+ * is turned on (EN==1). Note that without having VID0/1
+ * properly connected, turning pulldown off can be
+ * problematic. Thus, turn this off only when they are
+ * controllable by GPIO.
+ */
+ max8952_write_reg(max8952, MAX8952_REG_CONTROL, 0x0);
+ }
+
+ max8952_write_reg(max8952, MAX8952_REG_MODE0,
+ (max8952_read_reg(max8952,
+ MAX8952_REG_MODE0) & 0xC0) |
+ (pdata->dvs_mode[0] & 0x3F));
+ max8952_write_reg(max8952, MAX8952_REG_MODE1,
+ (max8952_read_reg(max8952,
+ MAX8952_REG_MODE1) & 0xC0) |
+ (pdata->dvs_mode[1] & 0x3F));
+ max8952_write_reg(max8952, MAX8952_REG_MODE2,
+ (max8952_read_reg(max8952,
+ MAX8952_REG_MODE2) & 0xC0) |
+ (pdata->dvs_mode[2] & 0x3F));
+ max8952_write_reg(max8952, MAX8952_REG_MODE3,
+ (max8952_read_reg(max8952,
+ MAX8952_REG_MODE3) & 0xC0) |
+ (pdata->dvs_mode[3] & 0x3F));
+
+ max8952_write_reg(max8952, MAX8952_REG_SYNC,
+ (max8952_read_reg(max8952, MAX8952_REG_SYNC) & 0x3F) |
+ ((pdata->sync_freq & 0x3) << 6));
+ max8952_write_reg(max8952, MAX8952_REG_RAMP,
+ (max8952_read_reg(max8952, MAX8952_REG_RAMP) & 0x1F) |
+ ((pdata->ramp_speed & 0x7) << 5));
+
+ i2c_set_clientdata(client, max8952);
+
+ return 0;
+}
+
+static const struct i2c_device_id max8952_ids[] = {
+ { "max8952", 0 },
+ { },
+};
+MODULE_DEVICE_TABLE(i2c, max8952_ids);
+
+static struct i2c_driver max8952_pmic_driver = {
+ .probe = max8952_pmic_probe,
+ .driver = {
+ .name = "max8952",
+ .of_match_table = of_match_ptr(max8952_dt_match),
+ },
+ .id_table = max8952_ids,
+};
+
+static int __init max8952_pmic_init(void)
+{
+ return i2c_add_driver(&max8952_pmic_driver);
+}
+subsys_initcall(max8952_pmic_init);
+
+static void __exit max8952_pmic_exit(void)
+{
+ i2c_del_driver(&max8952_pmic_driver);
+}
+module_exit(max8952_pmic_exit);
+
+MODULE_DESCRIPTION("MAXIM 8952 voltage regulator driver");
+MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
+MODULE_LICENSE("GPL");
Code Review / kvmfornfv.git / blobdiff