diff options
| author | Bastien Curutchet <bastien.curutchet@bootlin.com> | 2024-06-17 14:08:18 +0200 |
|---|---|---|
| committer | Andi Shyti <andi.shyti@kernel.org> | 2024-07-20 03:07:55 +0200 |
| commit | 45b8ee7182d5ef8df6959297046f86dc128d6a06 (patch) | |
| tree | 26abb3582dff0e3d2bcda1df274491289629029d | |
| parent | a618d86d5a1cf1ac6edbbe0e2b29649afb3decf0 (diff) | |
i2c: mux: gpio: Add support for the 'settle-time-us' property
Some hardware need some time to switch from a bus to another. This can
cause the first transfers following the selection of a bus to fail.
There is no way to configure this kind of waiting time in the driver.
Add support for the 'settle-time-us' device-tree property. When set,
the i2c_mux_gpio_select() applies a delay before returning, leaving
enough time to the hardware to switch to the new bus.
Signed-off-by: Bastien Curutchet <bastien.curutchet@bootlin.com>
Reviewed-by: Andi Shyti <andi.shyti@kernel.org>
Acked-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
| -rw-r--r-- | drivers/i2c/muxes/i2c-mux-gpio.c | 6 | ||||
| -rw-r--r-- | include/linux/platform_data/i2c-mux-gpio.h | 2 |
2 files changed, 8 insertions, 0 deletions
diff --git a/drivers/i2c/muxes/i2c-mux-gpio.c b/drivers/i2c/muxes/i2c-mux-gpio.c index c61e9d9ea695..944577bb09c1 100644 --- a/drivers/i2c/muxes/i2c-mux-gpio.c +++ b/drivers/i2c/muxes/i2c-mux-gpio.c @@ -6,6 +6,7 @@ */ #include <linux/bits.h> +#include <linux/delay.h> #include <linux/gpio/consumer.h> #include <linux/gpio/driver.h> #include <linux/i2c.h> @@ -37,6 +38,9 @@ static int i2c_mux_gpio_select(struct i2c_mux_core *muxc, u32 chan) i2c_mux_gpio_set(mux, chan); + if (mux->data.settle_time) + fsleep(mux->data.settle_time); + return 0; } @@ -116,6 +120,8 @@ static int i2c_mux_gpio_probe_fw(struct gpiomux *mux, if (device_property_read_u32(dev, "idle-state", &mux->data.idle)) mux->data.idle = I2C_MUX_GPIO_NO_IDLE; + device_property_read_u32(dev, "settle-time-us", &mux->data.settle_time); + return 0; } diff --git a/include/linux/platform_data/i2c-mux-gpio.h b/include/linux/platform_data/i2c-mux-gpio.h index 816a4cd3ccb5..96843aab4d1e 100644 --- a/include/linux/platform_data/i2c-mux-gpio.h +++ b/include/linux/platform_data/i2c-mux-gpio.h @@ -19,6 +19,7 @@ * position * @n_values: Number of multiplexer positions (busses to instantiate) * @idle: Bitmask to write to MUX when idle or GPIO_I2CMUX_NO_IDLE if not used + * @settle_time: Delay to wait when a new bus is selected */ struct i2c_mux_gpio_platform_data { int parent; @@ -26,6 +27,7 @@ struct i2c_mux_gpio_platform_data { const unsigned *values; int n_values; unsigned idle; + u32 settle_time; }; #endif /* _LINUX_I2C_MUX_GPIO_H */ |