[PATCH v3 05/18] mux: add mux_chip_resume() function

Thomas Richard
2024-02-15T15:18:06Z

The mux_chip_resume() function restores a mux_chip using the cached state
of each mux.

Signed-off-by: Thomas Richard <thomas.richard@bootlin.com>
---
drivers/mux/core.c | 30 ++++++++++++++++++++++++++++++
include/linux/mux/driver.h | 1 +
2 files changed, 31 insertions(+)

diff --git a/drivers/mux/core.c b/drivers/mux/core.c
index 775816112932..5db5a7698ad1 100644
--- a/drivers/mux/core.c
+++ b/drivers/mux/core.c
@@ -215,6 +215,36 @@ void mux_chip_free(struct mux_chip *mux_chip)
}
EXPORT_SYMBOL_GPL(mux_chip_free);

+/**
+ * mux_chip_resume() - restores the mux-chip state
+ * @mux_chip: The mux-chip to resume.
+ *
+ * Restores the mux-chip state.
+ *
+ * Return: Zero on success or a negative errno on error.
+ */
+int mux_chip_resume(struct mux_chip *mux_chip)
+{
+ int global_ret = 0;
+ int ret, i;
+
+ for (i = 0; i < mux_chip->controllers; ++i) {
+ struct mux_control *mux = &mux_chip->mux[i];
+
+ if (mux->cached_state == MUX_CACHE_UNKNOWN)
+ continue;
+
+ ret = mux_control_set(mux, mux->cached_state);
+ if (ret < 0) {
+ dev_err(&mux_chip->dev, "unable to restore state\n");
+ if (!global_ret)
+ global_ret = ret;
+ }
+ }
+ return global_ret;
+}
+EXPORT_SYMBOL_GPL(mux_chip_resume);
+
static void devm_mux_chip_release(struct device *dev, void *res)
{
struct mux_chip *mux_chip = *(struct mux_chip **)res;
diff --git a/include/linux/mux/driver.h b/include/linux/mux/driver.h
index 18824064f8c0..2a7e5ec5d540 100644
--- a/include/linux/mux/driver.h
+++ b/include/linux/mux/driver.h
@@ -88,6 +88,7 @@ struct mux_chip *mux_chip_alloc(struct device *dev,
int mux_chip_register(struct mux_chip *mux_chip);
void mux_chip_unregister(struct mux_chip *mux_chip);
void mux_chip_free(struct mux_chip *mux_chip);
+int mux_chip_resume(struct mux_chip *mux_chip);

struct mux_chip *devm_mux_chip_alloc(struct device *dev,
unsigned int controllers,

--
2.39.2