[PATCH 2/2] mux: gpio: Support settle-time-us property
From: Vincent Whitchurch <hidden>
Date: 2021-10-04 15:37:20
Also in:
lkml
Subsystem:
multiplexer subsystem, the rest · Maintainers:
Peter Rosin, Linus Torvalds
If the devicetree specifies that the hardware requires a settle time, add an appropriate delay after the mux GPIOs are set. Signed-off-by: Vincent Whitchurch <redacted> --- drivers/mux/gpio.c | 9 +++++++++ 1 file changed, 9 insertions(+)
diff --git a/drivers/mux/gpio.c b/drivers/mux/gpio.c
index cc5f2c1861d4..17d7e03e39f0 100644
--- a/drivers/mux/gpio.c
+++ b/drivers/mux/gpio.c@@ -8,6 +8,7 @@ */ #include <linux/bitmap.h> +#include <linux/delay.h> #include <linux/err.h> #include <linux/gpio/consumer.h> #include <linux/mod_devicetable.h>
@@ -18,12 +19,14 @@ struct mux_gpio { struct gpio_descs *gpios; + u32 delay; }; static int mux_gpio_set(struct mux_control *mux, int state) { struct mux_gpio *mux_gpio = mux_chip_priv(mux->chip); DECLARE_BITMAP(values, BITS_PER_TYPE(state)); + u32 delay = mux_gpio->delay; u32 value = state; bitmap_from_arr32(values, &value, BITS_PER_TYPE(value));
@@ -32,6 +35,9 @@ static int mux_gpio_set(struct mux_control *mux, int state) mux_gpio->gpios->desc, mux_gpio->gpios->info, values); + if (delay) + fsleep(delay); + return 0; }
@@ -72,6 +78,9 @@ static int mux_gpio_probe(struct platform_device *pdev) WARN_ON(pins != mux_gpio->gpios->ndescs); mux_chip->mux->states = BIT(pins); + mux_gpio->delay = 0; + device_property_read_u32(dev, "settle-time-us", &mux_gpio->delay); + ret = device_property_read_u32(dev, "idle-state", (u32 *)&idle_state); if (ret >= 0 && idle_state != MUX_IDLE_AS_IS) { if (idle_state < 0 || idle_state >= mux_chip->mux->states) {
--
2.28.0