linux/drivers/mfd/lp87565.c
Luca Ceresoli 50e4d7a2a6 mfd: lp87565: Handle optional reset pin
Optionally handle the NRST pin (active low reset) in order to start from a
known state during boot and to shut down the chip when rebooting.

Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2021-06-02 10:50:00 +01:00

132 lines
3.3 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2017 Texas Instruments Incorporated - https://www.ti.com/
*
* Author: Keerthy <j-keerthy@ti.com>
*/
#include <linux/gpio/consumer.h>
#include <linux/interrupt.h>
#include <linux/mfd/core.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/regmap.h>
#include <linux/mfd/lp87565.h>
static const struct regmap_config lp87565_regmap_config = {
.reg_bits = 8,
.val_bits = 8,
.max_register = LP87565_REG_MAX,
};
static const struct mfd_cell lp87565_cells[] = {
{ .name = "lp87565-q1-regulator", },
{ .name = "lp87565-q1-gpio", },
};
static const struct of_device_id of_lp87565_match_table[] = {
{ .compatible = "ti,lp87565", },
{
.compatible = "ti,lp87524-q1",
.data = (void *)LP87565_DEVICE_TYPE_LP87524_Q1,
},
{
.compatible = "ti,lp87565-q1",
.data = (void *)LP87565_DEVICE_TYPE_LP87565_Q1,
},
{
.compatible = "ti,lp87561-q1",
.data = (void *)LP87565_DEVICE_TYPE_LP87561_Q1,
},
{}
};
MODULE_DEVICE_TABLE(of, of_lp87565_match_table);
static int lp87565_probe(struct i2c_client *client,
const struct i2c_device_id *ids)
{
struct lp87565 *lp87565;
const struct of_device_id *of_id;
int ret;
unsigned int otpid;
lp87565 = devm_kzalloc(&client->dev, sizeof(*lp87565), GFP_KERNEL);
if (!lp87565)
return -ENOMEM;
lp87565->dev = &client->dev;
lp87565->regmap = devm_regmap_init_i2c(client, &lp87565_regmap_config);
if (IS_ERR(lp87565->regmap)) {
ret = PTR_ERR(lp87565->regmap);
dev_err(lp87565->dev,
"Failed to initialize register map: %d\n", ret);
return ret;
}
lp87565->reset_gpio = devm_gpiod_get_optional(lp87565->dev, "reset",
GPIOD_OUT_LOW);
if (IS_ERR(lp87565->reset_gpio)) {
ret = PTR_ERR(lp87565->reset_gpio);
if (ret == -EPROBE_DEFER)
return ret;
}
if (lp87565->reset_gpio) {
gpiod_set_value_cansleep(lp87565->reset_gpio, 1);
/* The minimum assertion time is undocumented, just guess */
usleep_range(2000, 4000);
gpiod_set_value_cansleep(lp87565->reset_gpio, 0);
/* Min 1.2 ms before first I2C transaction */
usleep_range(1500, 3000);
}
ret = regmap_read(lp87565->regmap, LP87565_REG_OTP_REV, &otpid);
if (ret) {
dev_err(lp87565->dev, "Failed to read OTP ID\n");
return ret;
}
lp87565->rev = otpid & LP87565_OTP_REV_OTP_ID;
of_id = of_match_device(of_lp87565_match_table, &client->dev);
if (of_id)
lp87565->dev_type = (enum lp87565_device_type)of_id->data;
i2c_set_clientdata(client, lp87565);
return devm_mfd_add_devices(lp87565->dev, PLATFORM_DEVID_AUTO,
lp87565_cells, ARRAY_SIZE(lp87565_cells),
NULL, 0, NULL);
}
static void lp87565_shutdown(struct i2c_client *client)
{
struct lp87565 *lp87565 = i2c_get_clientdata(client);
gpiod_set_value_cansleep(lp87565->reset_gpio, 1);
}
static const struct i2c_device_id lp87565_id_table[] = {
{ "lp87565-q1", 0 },
{ },
};
MODULE_DEVICE_TABLE(i2c, lp87565_id_table);
static struct i2c_driver lp87565_driver = {
.driver = {
.name = "lp87565",
.of_match_table = of_lp87565_match_table,
},
.probe = lp87565_probe,
.shutdown = lp87565_shutdown,
.id_table = lp87565_id_table,
};
module_i2c_driver(lp87565_driver);
MODULE_AUTHOR("J Keerthy <j-keerthy@ti.com>");
MODULE_DESCRIPTION("lp87565 chip family Multi-Function Device driver");
MODULE_LICENSE("GPL v2");