linux/drivers/regulator/tps62360-regulator.c
Axel Lin 46783a046e regulator: tps62360: Remove pointless test for unsigned less than zero
The variable 'selector' is a 'unsigned int', so it can never be less than zero.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2012-03-11 20:48:40 +00:00

473 lines
12 KiB
C

/*
* tps62360.c -- TI tps62360
*
* Driver for processor core supply tps62360 and tps62361B
*
* 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/tps62360.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_VSET2 2
#define REG_VSET3 3
#define REG_CONTROL 4
#define REG_TEMP 5
#define REG_RAMPCTRL 6
#define REG_CHIPID 8
enum chips {TPS62360, TPS62361};
#define TPS62360_BASE_VOLTAGE 770
#define TPS62360_N_VOLTAGES 64
#define TPS62361_BASE_VOLTAGE 500
#define TPS62361_N_VOLTAGES 128
/* tps 62360 chip information */
struct tps62360_chip {
const char *name;
struct device *dev;
struct regulator_desc desc;
struct i2c_client *client;
struct regulator_dev *rdev;
struct regmap *regmap;
int chip_id;
int vsel0_gpio;
int vsel1_gpio;
int voltage_base;
u8 voltage_reg_mask;
bool en_internal_pulldn;
bool en_force_pwm;
bool en_discharge;
bool valid_gpios;
int lru_index[4];
int curr_vset_vsel[4];
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 tps62360_chip *tps,
int req_vsel, int *vset_reg_id)
{
int i;
bool found = false;
int new_vset_reg = tps->lru_index[3];
int found_index = 3;
for (i = 0; i < 4; ++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 tps62360_dcdc_get_voltage(struct regulator_dev *dev)
{
struct tps62360_chip *tps = rdev_get_drvdata(dev);
int vsel;
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;
}
vsel = (int)data & tps->voltage_reg_mask;
return (tps->voltage_base + vsel * 10) * 1000;
}
static int tps62360_dcdc_set_voltage(struct regulator_dev *dev,
int min_uV, int max_uV, unsigned *selector)
{
struct tps62360_chip *tps = rdev_get_drvdata(dev);
int vsel;
int ret;
bool found = false;
int new_vset_id = tps->curr_vset_id;
if (max_uV < min_uV)
return -EINVAL;
if (min_uV >
((tps->voltage_base + (tps->desc.n_voltages - 1) * 10) * 1000))
return -EINVAL;
if (max_uV < tps->voltage_base * 1000)
return -EINVAL;
vsel = DIV_ROUND_UP(min_uV - (tps->voltage_base * 1000), 10000);
if (selector)
*selector = (vsel & tps->voltage_reg_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,
tps->voltage_reg_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->vsel0_gpio,
new_vset_id & 0x1);
gpio_set_value_cansleep(tps->vsel1_gpio,
(new_vset_id >> 1) & 0x1);
}
return 0;
}
static int tps62360_dcdc_list_voltage(struct regulator_dev *dev,
unsigned selector)
{
struct tps62360_chip *tps = rdev_get_drvdata(dev);
if (selector >= tps->desc.n_voltages)
return -EINVAL;
return (tps->voltage_base + selector * 10) * 1000;
}
static struct regulator_ops tps62360_dcdc_ops = {
.get_voltage = tps62360_dcdc_get_voltage,
.set_voltage = tps62360_dcdc_set_voltage,
.list_voltage = tps62360_dcdc_list_voltage,
};
static int tps62360_init_force_pwm(struct tps62360_chip *tps,
struct tps62360_regulator_platform_data *pdata,
int vset_id)
{
unsigned int data;
int ret;
ret = regmap_read(tps->regmap, REG_VSET0 + vset_id, &data);
if (ret < 0) {
dev_err(tps->dev, "%s() fails in writing reg %d\n",
__func__, REG_VSET0 + vset_id);
return ret;
}
tps->curr_vset_vsel[vset_id] = data & tps->voltage_reg_mask;
if (pdata->en_force_pwm)
data |= BIT(7);
else
data &= ~BIT(7);
ret = regmap_write(tps->regmap, REG_VSET0 + vset_id, data);
if (ret < 0)
dev_err(tps->dev, "%s() fails in writing reg %d\n",
__func__, REG_VSET0 + vset_id);
return ret;
}
static int tps62360_init_dcdc(struct tps62360_chip *tps,
struct tps62360_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, 0xE0);
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;
}
/* Initailize force PWM mode */
if (tps->valid_gpios) {
for (i = 0; i < 4; ++i) {
ret = tps62360_init_force_pwm(tps, pdata, i);
if (ret < 0)
return ret;
}
} else {
ret = tps62360_init_force_pwm(tps, pdata, tps->curr_vset_id);
if (ret < 0)
return ret;
}
/* Reset output discharge path to reduce power consumption */
ret = regmap_update_bits(tps->regmap, REG_RAMPCTRL, BIT(2), 0);
if (ret < 0)
dev_err(tps->dev, "%s() fails in updating reg %d\n",
__func__, REG_RAMPCTRL);
return ret;
}
static const struct regmap_config tps62360_regmap_config = {
.reg_bits = 8,
.val_bits = 8,
};
static int __devinit tps62360_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct tps62360_regulator_platform_data *pdata;
struct regulator_dev *rdev;
struct tps62360_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_force_pwm = pdata->en_force_pwm;
tps->en_discharge = pdata->en_discharge;
tps->en_internal_pulldn = pdata->en_internal_pulldn;
tps->vsel0_gpio = pdata->vsel0_gpio;
tps->vsel1_gpio = pdata->vsel1_gpio;
tps->client = client;
tps->dev = &client->dev;
tps->name = id->name;
tps->voltage_base = (id->driver_data == TPS62360) ?
TPS62360_BASE_VOLTAGE : TPS62361_BASE_VOLTAGE;
tps->voltage_reg_mask = (id->driver_data == TPS62360) ? 0x3F : 0x7F;
tps->desc.name = id->name;
tps->desc.id = 0;
tps->desc.n_voltages = (id->driver_data == TPS62360) ?
TPS62360_N_VOLTAGES : TPS62361_N_VOLTAGES;
tps->desc.ops = &tps62360_dcdc_ops;
tps->desc.type = REGULATOR_VOLTAGE;
tps->desc.owner = THIS_MODULE;
tps->regmap = regmap_init_i2c(client, &tps62360_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->vsel1_def_state & 1) * 2 +
(pdata->vsel0_def_state & 1);
tps->lru_index[0] = tps->curr_vset_id;
tps->valid_gpios = false;
if (gpio_is_valid(tps->vsel0_gpio) && gpio_is_valid(tps->vsel1_gpio)) {
ret = gpio_request(tps->vsel0_gpio, "tps62360-vsel0");
if (ret) {
dev_err(&client->dev,
"Err: Could not obtain vsel0 GPIO %d: %d\n",
tps->vsel0_gpio, ret);
goto err_gpio0;
}
ret = gpio_direction_output(tps->vsel0_gpio,
pdata->vsel0_def_state);
if (ret) {
dev_err(&client->dev, "Err: Could not set direction of"
"vsel0 GPIO %d: %d\n", tps->vsel0_gpio, ret);
gpio_free(tps->vsel0_gpio);
goto err_gpio0;
}
ret = gpio_request(tps->vsel1_gpio, "tps62360-vsel1");
if (ret) {
dev_err(&client->dev,
"Err: Could not obtain vsel1 GPIO %d: %d\n",
tps->vsel1_gpio, ret);
goto err_gpio1;
}
ret = gpio_direction_output(tps->vsel1_gpio,
pdata->vsel1_def_state);
if (ret) {
dev_err(&client->dev, "Err: Could not set direction of"
"vsel1 GPIO %d: %d\n", tps->vsel1_gpio, ret);
gpio_free(tps->vsel1_gpio);
goto err_gpio1;
}
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 < 4; ++i)
tps->lru_index[i] = i;
tps->lru_index[0] = tps->curr_vset_id;
tps->lru_index[tps->curr_vset_id] = 0;
}
ret = tps62360_init_dcdc(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->reg_init_data, tps, NULL);
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->vsel1_gpio))
gpio_free(tps->vsel1_gpio);
err_gpio1:
if (gpio_is_valid(tps->vsel0_gpio))
gpio_free(tps->vsel0_gpio);
err_gpio0:
regmap_exit(tps->regmap);
return ret;
}
/**
* tps62360_remove - tps62360 driver i2c remove handler
* @client: i2c driver client device structure
*
* Unregister TPS driver as an i2c client device driver
*/
static int __devexit tps62360_remove(struct i2c_client *client)
{
struct tps62360_chip *tps = i2c_get_clientdata(client);
if (gpio_is_valid(tps->vsel1_gpio))
gpio_free(tps->vsel1_gpio);
if (gpio_is_valid(tps->vsel0_gpio))
gpio_free(tps->vsel0_gpio);
regulator_unregister(tps->rdev);
regmap_exit(tps->regmap);
return 0;
}
static void tps62360_shutdown(struct i2c_client *client)
{
struct tps62360_chip *tps = i2c_get_clientdata(client);
int st;
if (!tps->en_discharge)
return;
/* Configure the output discharge path */
st = regmap_update_bits(tps->regmap, REG_RAMPCTRL, BIT(2), BIT(2));
if (st < 0)
dev_err(tps->dev, "%s() fails in updating reg %d\n",
__func__, REG_RAMPCTRL);
}
static const struct i2c_device_id tps62360_id[] = {
{.name = "tps62360", .driver_data = TPS62360},
{.name = "tps62361", .driver_data = TPS62361},
{},
};
MODULE_DEVICE_TABLE(i2c, tps62360_id);
static struct i2c_driver tps62360_i2c_driver = {
.driver = {
.name = "tps62360",
.owner = THIS_MODULE,
},
.probe = tps62360_probe,
.remove = __devexit_p(tps62360_remove),
.shutdown = tps62360_shutdown,
.id_table = tps62360_id,
};
static int __init tps62360_init(void)
{
return i2c_add_driver(&tps62360_i2c_driver);
}
subsys_initcall(tps62360_init);
static void __exit tps62360_cleanup(void)
{
i2c_del_driver(&tps62360_i2c_driver);
}
module_exit(tps62360_cleanup);
MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
MODULE_DESCRIPTION("TPS62360 voltage regulator driver");
MODULE_LICENSE("GPL v2");