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authorBastien Curutchet <bastien.curutchet@bootlin.com>2024-06-17 14:08:18 +0200
committerAndi Shyti <andi.shyti@kernel.org>2024-07-20 03:07:55 +0200
commit45b8ee7182d5ef8df6959297046f86dc128d6a06 (patch)
tree26abb3582dff0e3d2bcda1df274491289629029d /drivers/i2c
parenta618d86d5a1cf1ac6edbbe0e2b29649afb3decf0 (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>
Diffstat (limited to 'drivers/i2c')
-rw-r--r--drivers/i2c/muxes/i2c-mux-gpio.c6
1 files changed, 6 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;
}