diff options
Diffstat (limited to 'drivers/regulator/tps6238x0-regulator.c')
| -rw-r--r-- | drivers/regulator/tps6238x0-regulator.c | 470 |
1 files changed, 470 insertions, 0 deletions
diff --git a/drivers/regulator/tps6238x0-regulator.c b/drivers/regulator/tps6238x0-regulator.c new file mode 100644 index 000000000000..611b9425a263 --- /dev/null +++ b/drivers/regulator/tps6238x0-regulator.c @@ -0,0 +1,470 @@ +/* + * tps6238x0-regulator.c -- TI tps623850/tps623860/tps623870 + * + * Driver for processor core supply tps623850, tps623860 and tps623870 + * + * Copyright (c) 2012, NVIDIA Corporation. + * + * Author: Laxman Dewangan <ldewangan@nvidia.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 version 2. + * + * This program is distributed "as is" WITHOUT ANY WARRANTY of any kind, + * whether express or implied; 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/kernel.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/err.h> +#include <linux/platform_device.h> +#include <linux/regulator/driver.h> +#include <linux/regulator/machine.h> +#include <linux/regulator/tps6238x0-regulator.h> +#include <linux/gpio.h> +#include <linux/i2c.h> +#include <linux/delay.h> +#include <linux/slab.h> +#include <linux/regmap.h> + +/* Register definitions */ +#define REG_VSET0 0 +#define REG_VSET1 1 +#define REG_MODE0 2 +#define REG_MODE1 3 +#define REG_CONTROL 4 +#define REG_EXCEPTION 5 +#define REG_RAMPCTRL 6 +#define REG_IOUT 7 +#define REG_CHIPID 8 + +#define TPS6238X0_BASE_VOLTAGE 500000 +#define TPS6238X0_N_VOLTAGES 128 +#define TPS6238X0_MAX_VSET 2 +#define TPS6238X0_VOUT_MASK 0x7F + +/* tps 6238x0 chip information */ +struct tps6238x0_chip { + const char *name; + struct device *dev; + struct regulator_desc desc; + struct regulator_dev *rdev; + struct regmap *regmap; + int vsel_gpio; + int change_uv_per_us; + bool en_internal_pulldn; + bool valid_gpios; + int lru_index[TPS6238X0_MAX_VSET]; + int curr_vset_vsel[TPS6238X0_MAX_VSET]; + int curr_vset_id; +}; + +/* + * find_voltage_set_register: Find new voltage configuration register + * (VSET) id. + * The finding of the new VSET register will be based on the LRU mechanism. + * Each VSET register will have different voltage configured . This + * Function will look if any of the VSET register have requested voltage set + * or not. + * - If it is already there then it will make that register as most + * recently used and return as found so that caller need not to set + * the VSET register but need to set the proper gpios to select this + * VSET register. + * - If requested voltage is not found then it will use the least + * recently mechanism to get new VSET register for new configuration + * and will return not_found so that caller need to set new VSET + * register and then gpios (both). + */ +static bool find_voltage_set_register(struct tps6238x0_chip *tps, + int req_vsel, int *vset_reg_id) +{ + int i; + bool found = false; + int new_vset_reg = tps->lru_index[1]; + int found_index = 1; + for (i = 0; i < TPS6238X0_MAX_VSET; ++i) { + if (tps->curr_vset_vsel[tps->lru_index[i]] == req_vsel) { + new_vset_reg = tps->lru_index[i]; + found_index = i; + found = true; + goto update_lru_index; + } + } + +update_lru_index: + for (i = found_index; i > 0; i--) + tps->lru_index[i] = tps->lru_index[i - 1]; + + tps->lru_index[0] = new_vset_reg; + *vset_reg_id = new_vset_reg; + return found; +} + +static int tps6238x0_get_voltage_sel(struct regulator_dev *dev) +{ + struct tps6238x0_chip *tps = rdev_get_drvdata(dev); + unsigned int data; + int ret; + + ret = regmap_read(tps->regmap, REG_VSET0 + tps->curr_vset_id, &data); + if (ret < 0) { + dev_err(tps->dev, "%s: Error in reading register %d\n", + __func__, REG_VSET0 + tps->curr_vset_id); + return ret; + } + return data & TPS6238X0_VOUT_MASK; +} + +static int tps6238x0_set_voltage(struct regulator_dev *dev, + int min_uV, int max_uV, unsigned *selector) +{ + struct tps6238x0_chip *tps = rdev_get_drvdata(dev); + int vsel; + int ret; + bool found = false; + int new_vset_id = tps->curr_vset_id; + + if (min_uV > + ((TPS6238X0_BASE_VOLTAGE + (TPS6238X0_N_VOLTAGES - 1) * 10000))) + return -EINVAL; + + if ((max_uV < min_uV) || (max_uV < TPS6238X0_BASE_VOLTAGE)) + return -EINVAL; + + vsel = DIV_ROUND_UP(min_uV - TPS6238X0_BASE_VOLTAGE, 10000); + if (selector) + *selector = (vsel & TPS6238X0_VOUT_MASK); + + /* + * If gpios are available to select the VSET register then least + * recently used register for new configuration. + */ + if (tps->valid_gpios) + found = find_voltage_set_register(tps, vsel, &new_vset_id); + + if (!found) { + ret = regmap_update_bits(tps->regmap, REG_VSET0 + new_vset_id, + TPS6238X0_VOUT_MASK, vsel); + if (ret < 0) { + dev_err(tps->dev, "%s: Error in updating register %d\n", + __func__, REG_VSET0 + new_vset_id); + return ret; + } + tps->curr_vset_id = new_vset_id; + tps->curr_vset_vsel[new_vset_id] = vsel; + } + + /* Select proper VSET register vio gpios */ + if (tps->valid_gpios) + gpio_set_value_cansleep(tps->vsel_gpio, new_vset_id & 0x1); + return 0; +} + +static int tps6238x0_list_voltage(struct regulator_dev *dev, + unsigned selector) +{ + struct tps6238x0_chip *tps = rdev_get_drvdata(dev); + + if ((selector < 0) || (selector >= tps->desc.n_voltages)) + return -EINVAL; + + return TPS6238X0_BASE_VOLTAGE + selector * 10000; +} + +static int tps6238x0_regulator_enable_time(struct regulator_dev *rdev) +{ + return 300; +} + +static int tps6238x0_set_voltage_time_sel(struct regulator_dev *rdev, + unsigned int old_selector, unsigned int new_selector) +{ + struct tps6238x0_chip *tps = rdev_get_drvdata(rdev); + int old_uV, new_uV; + old_uV = tps6238x0_list_voltage(rdev, old_selector); + + if (old_uV < 0) + return old_uV; + + new_uV = tps6238x0_list_voltage(rdev, new_selector); + if (new_uV < 0) + return new_uV; + + return DIV_ROUND_UP(abs(old_uV - new_uV), + tps->change_uv_per_us); +} + +static int tps6238x0_is_enable(struct regulator_dev *rdev) +{ + struct tps6238x0_chip *tps = rdev_get_drvdata(rdev); + unsigned int data; + int ret; + + ret = regmap_read(tps->regmap, REG_VSET0 + tps->curr_vset_id, &data); + if (ret < 0) { + dev_err(tps->dev, "%s: Error in reading register %d\n", + __func__, REG_VSET0 + tps->curr_vset_id); + return ret; + } + return !!(data & BIT(7)); +} + +static int tps6238x0_enable(struct regulator_dev *rdev) +{ + struct tps6238x0_chip *tps = rdev_get_drvdata(rdev); + int ret; + int i; + + /* Enable required VSET configuration */ + for (i = 0; i < TPS6238X0_MAX_VSET; ++i) { + unsigned int en = 0; + if (tps->valid_gpios || (i == tps->curr_vset_id)) + en = BIT(7); + + ret = regmap_update_bits(tps->regmap, REG_VSET0 + i, + BIT(7), en); + if (ret < 0) { + dev_err(tps->dev, "%s() fails in updating reg %d\n", + __func__, REG_VSET0 + i); + return ret; + } + } + return ret; +} + +static int tps6238x0_disable(struct regulator_dev *rdev) +{ + struct tps6238x0_chip *tps = rdev_get_drvdata(rdev); + int ret; + int i; + + /* Disable required VSET configuration */ + for (i = 0; i < TPS6238X0_MAX_VSET; ++i) { + ret = regmap_update_bits(tps->regmap, REG_VSET0 + i, + BIT(7), 0); + if (ret < 0) { + dev_err(tps->dev, "%s() fails in updating reg %d\n", + __func__, REG_VSET0 + i); + return ret; + } + } + return ret; +} + +static struct regulator_ops tps6238x0_ops = { + .is_enabled = tps6238x0_is_enable, + .enable = tps6238x0_enable, + .disable = tps6238x0_disable, + .enable_time = tps6238x0_regulator_enable_time, + .set_voltage_time_sel = tps6238x0_set_voltage_time_sel, + .get_voltage_sel = tps6238x0_get_voltage_sel, + .set_voltage = tps6238x0_set_voltage, + .list_voltage = tps6238x0_list_voltage, +}; + +static int __devinit tps6238x0_configure(struct tps6238x0_chip *tps, + struct tps6238x0_regulator_platform_data *pdata) +{ + int ret; + int i; + + /* Initailize internal pull up/down control */ + if (tps->en_internal_pulldn) + ret = regmap_write(tps->regmap, REG_CONTROL, 0xC0); + else + ret = regmap_write(tps->regmap, REG_CONTROL, 0x0); + if (ret < 0) { + dev_err(tps->dev, "%s() fails in writing reg %d\n", + __func__, REG_CONTROL); + return ret; + } + + /* Enable required VSET configuration */ + for (i = 0; i < TPS6238X0_MAX_VSET; ++i) { + unsigned int en = 0; + if (tps->valid_gpios || (i == tps->curr_vset_id)) + en = BIT(7); + + ret = regmap_update_bits(tps->regmap, REG_VSET0 + i, + BIT(7), en); + if (ret < 0) { + dev_err(tps->dev, "%s() fails in updating reg %d\n", + __func__, REG_VSET0 + i); + return ret; + } + } + + /* Enable output discharge path to have faster discharge */ + ret = regmap_update_bits(tps->regmap, REG_RAMPCTRL, BIT(2), BIT(2)); + if (ret < 0) + dev_err(tps->dev, "%s() fails in updating reg %d\n", + __func__, REG_RAMPCTRL); + tps->change_uv_per_us = 312; + return ret; +} + +static const struct regmap_config tps6238x0_regmap_config = { + .reg_bits = 8, + .val_bits = 8, + .max_register = REG_CHIPID, + .num_reg_defaults_raw = REG_CHIPID + 1, + .cache_type = REGCACHE_RBTREE, +}; + +static int __devinit tps6238x0_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct tps6238x0_regulator_platform_data *pdata; + struct regulator_dev *rdev; + struct tps6238x0_chip *tps; + int ret; + int i; + + pdata = client->dev.platform_data; + if (!pdata) { + dev_err(&client->dev, "%s() Err: Platform data not found\n", + __func__); + return -EIO; + } + + tps = devm_kzalloc(&client->dev, sizeof(*tps), GFP_KERNEL); + if (!tps) { + dev_err(&client->dev, "%s() Err: Memory allocation fails\n", + __func__); + return -ENOMEM; + } + + tps->en_internal_pulldn = pdata->en_internal_pulldn; + tps->vsel_gpio = pdata->vsel_gpio; + tps->dev = &client->dev; + + tps->desc.name = id->name; + tps->desc.id = 0; + tps->desc.n_voltages = TPS6238X0_N_VOLTAGES; + tps->desc.ops = &tps6238x0_ops; + tps->desc.type = REGULATOR_VOLTAGE; + tps->desc.owner = THIS_MODULE; + tps->regmap = devm_regmap_init_i2c(client, &tps6238x0_regmap_config); + if (IS_ERR(tps->regmap)) { + ret = PTR_ERR(tps->regmap); + dev_err(&client->dev, "%s() Err: Failed to allocate register" + "map: %d\n", __func__, ret); + return ret; + } + i2c_set_clientdata(client, tps); + + tps->curr_vset_id = (pdata->vsel_def_state & 1); + tps->lru_index[0] = tps->curr_vset_id; + tps->valid_gpios = false; + + if (gpio_is_valid(tps->vsel_gpio)) { + int gpio_flag; + gpio_flag = (tps->curr_vset_id) ? + GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW; + ret = gpio_request_one(tps->vsel_gpio, + gpio_flag, "tps6238x0-vsel0"); + if (ret) { + dev_err(&client->dev, + "Err: Could not obtain vsel GPIO %d: %d\n", + tps->vsel_gpio, ret); + return ret; + } + tps->valid_gpios = true; + + /* + * Initialize the lru index with vset_reg id + * The index 0 will be most recently used and + * set with the tps->curr_vset_id */ + for (i = 0; i < TPS6238X0_MAX_VSET; ++i) + tps->lru_index[i] = i; + tps->lru_index[0] = tps->curr_vset_id; + tps->lru_index[tps->curr_vset_id] = 0; + } + + ret = tps6238x0_configure(tps, pdata); + if (ret < 0) { + dev_err(tps->dev, "%s() Err: Init fails with = %d\n", + __func__, ret); + goto err_init; + } + + /* Register the regulators */ + rdev = regulator_register(&tps->desc, &client->dev, + pdata->init_data, tps); + if (IS_ERR(rdev)) { + dev_err(tps->dev, "%s() Err: Failed to register %s\n", + __func__, id->name); + ret = PTR_ERR(rdev); + goto err_init; + } + + tps->rdev = rdev; + return 0; + +err_init: + if (gpio_is_valid(tps->vsel_gpio)) + gpio_free(tps->vsel_gpio); + + return ret; +} + +/** + * tps6238x0_remove - tps62360 driver i2c remove handler + * @client: i2c driver client device structure + * + * Unregister TPS driver as an i2c client device driver + */ +static int __devexit tps6238x0_remove(struct i2c_client *client) +{ + struct tps6238x0_chip *tps = i2c_get_clientdata(client); + + if (gpio_is_valid(tps->vsel_gpio)) + gpio_free(tps->vsel_gpio); + + regulator_unregister(tps->rdev); + return 0; +} + +static const struct i2c_device_id tps6238x0_id[] = { + {.name = "tps623850", }, + {.name = "tps623860", }, + {.name = "tps623870", }, + {}, +}; + +MODULE_DEVICE_TABLE(i2c, tps6238x0_id); + +static struct i2c_driver tps6238x0_i2c_driver = { + .driver = { + .name = "tps6238x0", + .owner = THIS_MODULE, + }, + .probe = tps6238x0_probe, + .remove = __devexit_p(tps6238x0_remove), + .id_table = tps6238x0_id, +}; + +static int __init tps6238x0_init(void) +{ + return i2c_add_driver(&tps6238x0_i2c_driver); +} +subsys_initcall(tps6238x0_init); + +static void __exit tps6238x0_cleanup(void) +{ + i2c_del_driver(&tps6238x0_i2c_driver); +} +module_exit(tps6238x0_cleanup); + +MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>"); +MODULE_DESCRIPTION("TPS623850/TPS623860/TPS623870 voltage regulator driver"); +MODULE_LICENSE("GPL v2"); |