[PATCH 2/2] i2c: i2c-mux-gpio: Add support 'select-delay' property
From: Horatiu Vultur <horatiu.vultur@microchip.com>
Date: 2021-10-13 14:13:16
Also in:
linux-i2c, lkml
Subsystem:
generic gpio i2c multiplexer driver, i2c muxes, i2c subsystem, the rest · Maintainers:
Peter Korsgaard, Peter Rosin, Andi Shyti, Linus Torvalds
Use select-delay property to add a delay once the mux state is changed. This is required on some platforms to allow the GPIO signals to get stabilized. Signed-off-by: Lars Povlsen <redacted> Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com> --- drivers/i2c/muxes/i2c-mux-gpio.c | 7 +++++++ 1 file changed, 7 insertions(+)
diff --git a/drivers/i2c/muxes/i2c-mux-gpio.c b/drivers/i2c/muxes/i2c-mux-gpio.c
index bac415a52b78..1cc69eb67221 100644
--- a/drivers/i2c/muxes/i2c-mux-gpio.c
+++ b/drivers/i2c/muxes/i2c-mux-gpio.c@@ -13,6 +13,8 @@ #include <linux/slab.h> #include <linux/bits.h> #include <linux/gpio/consumer.h> +#include <linux/delay.h> + /* FIXME: stop poking around inside gpiolib */ #include "../../gpio/gpiolib.h"
@@ -20,6 +22,7 @@ struct gpiomux { struct i2c_mux_gpio_platform_data data; int ngpios; struct gpio_desc **gpios; + int select_delay; }; static void i2c_mux_gpio_set(const struct gpiomux *mux, unsigned val)
@@ -29,6 +32,8 @@ static void i2c_mux_gpio_set(const struct gpiomux *mux, unsigned val) values[0] = val; gpiod_set_array_value_cansleep(mux->ngpios, mux->gpios, NULL, values); + if (mux->select_delay) + udelay(mux->select_delay); } static int i2c_mux_gpio_select(struct i2c_mux_core *muxc, u32 chan)
@@ -153,6 +158,8 @@ static int i2c_mux_gpio_probe_fw(struct gpiomux *mux, if (fwnode_property_read_u32(dev->fwnode, "idle-state", &mux->data.idle)) mux->data.idle = I2C_MUX_GPIO_NO_IDLE; + fwnode_property_read_u32(dev->fwnode, "select-delay", &mux->select_delay); + return 0; }
--
2.33.0