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 <lars.povlsen@xxxxxxxxxxxxx>
Signed-off-by: Horatiu Vultur <horatiu.vultur@xxxxxxxxxxxxx>
---
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
