diff options
| author | Luca Ceresoli <luca@lucaceresoli.net> | 2021-02-26 15:28:52 +0100 |
|---|---|---|
| committer | Lee Jones <lee.jones@linaro.org> | 2021-06-02 10:50:00 +0100 |
| commit | 50e4d7a2a667353321d4315fcc025e76c4fa2a89 (patch) | |
| tree | ae435572afdf4c4e83b82713130200e1861c9191 /drivers | |
| parent | 4700ef326556ed74aba188f12396740a8c1c21dd (diff) | |
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>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/mfd/lp87565.c | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/drivers/mfd/lp87565.c b/drivers/mfd/lp87565.c index 9c21483d9653..a52ab76febb3 100644 --- a/drivers/mfd/lp87565.c +++ b/drivers/mfd/lp87565.c @@ -5,6 +5,7 @@ * Author: Keerthy <j-keerthy@ti.com> */ +#include <linux/gpio/consumer.h> #include <linux/interrupt.h> #include <linux/mfd/core.h> #include <linux/module.h> @@ -64,6 +65,24 @@ static int lp87565_probe(struct i2c_client *client, 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"); @@ -83,6 +102,13 @@ static int lp87565_probe(struct i2c_client *client, 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 }, { }, @@ -95,6 +121,7 @@ static struct i2c_driver lp87565_driver = { .of_match_table = of_lp87565_match_table, }, .probe = lp87565_probe, + .shutdown = lp87565_shutdown, .id_table = lp87565_id_table, }; module_i2c_driver(lp87565_driver); |