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alistair23-linux/drivers/regulator/max8952.c
Linus Walleij 63239e4bf7
regulator: Fetch enable gpiods nonexclusive 
Since the core regulator code is treating GPIO descriptors as
nonexclusive, i.e. it assumes that the enable GPIO line may be
shared with several regulators, let's add the flag introduced
for fixing this problem on fixed regulators to all drivers
fetching GPIO descriptors to avoid possible regressions.

Reported-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
2018-10-15 10:48:59 +01:00

355 lines
9.3 KiB
C
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/*
* 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/gpio/consumer.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 const 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);
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, &regulator);
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;
struct gpio_desc *gpiod;
enum gpiod_flags gflags;
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;
if (pdata->reg_data->constraints.boot_on)
gflags = GPIOD_OUT_HIGH;
else
gflags = GPIOD_OUT_LOW;
gflags |= GPIOD_FLAGS_BIT_NONEXCLUSIVE;
gpiod = devm_gpiod_get_optional(&client->dev,
"max8952,en",
gflags);
if (IS_ERR(gpiod))
return PTR_ERR(gpiod);
if (gpiod)
config.ena_gpiod = gpiod;
rdev = devm_regulator_register(&client->dev, &regulator, &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");
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