Commit 69f47cad authored by Kyle Swenson's avatar Kyle Swenson Committed by Jakub Kicinski
Browse files

net: pse-pd: tps23881: Support reset-gpios 



The TPS23880/1 has an active-low reset pin that some boards connect to
the SoC to control when the TPS23880 is pulled out of reset.

Add support for this via a reset-gpios property in the DTS.

Signed-off-by: default avatarKyle Swenson <kyle.swenson@est.tech>
Acked-by: default avatarOleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: default avatarKory Maincent <kory.maincent@bootlin.com>
Link: https://patch.msgid.link/20240822220100.3030184-3-kyle.swenson@est.tech


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent ec82fa2c

drivers/net/pse-pd/tps23881.c

+21 −0
Original line number Diff line number Diff line
@@ -8,6 +8,7 @@ 
#include <linux/bitfield.h>

#include <linux/delay.h>

#include <linux/firmware.h>

#include <linux/gpio/consumer.h>

#include <linux/i2c.h>

#include <linux/module.h>

#include <linux/of.h>
@@ -737,6 +738,7 @@ static int tps23881_i2c_probe(struct i2c_client *client) 
{

	struct device *dev = &client->dev;

	struct tps23881_priv *priv;

	struct gpio_desc *reset;

	int ret;

	u8 val;
@@ -749,6 +751,25 @@ static int tps23881_i2c_probe(struct i2c_client *client) 
	if (!priv)

		return -ENOMEM;



	reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);

	if (IS_ERR(reset))

		return dev_err_probe(&client->dev, PTR_ERR(reset), "Failed to get reset GPIO\n");



	if (reset) {

		/* TPS23880 datasheet (Rev G) indicates minimum reset pulse is 5us */

		usleep_range(5, 10);

		gpiod_set_value_cansleep(reset, 0); /* De-assert reset */



		/* TPS23880 datasheet indicates the minimum time after power on reset

		 * should be 20ms, but the document describing how to load SRAM ("How

		 * to Load TPS2388x SRAM and Parity Code over I2C" (Rev E))

		 * indicates we should delay that programming by at least 50ms. So

		 * we'll wait the entire 50ms here to ensure we're safe to go to the

		 * SRAM loading proceedure.

		 */

		msleep(50);

	}



	ret = i2c_smbus_read_byte_data(client, TPS23881_REG_DEVID);

	if (ret < 0)

		return ret;