diff mbox series

[v6,04/12] mux: add mux_chip_resume() function

Message ID 20240102-j7200-pcie-s2r-v6-4-4656ef6e6d66@bootlin.com
State New
Headers show
Series Add suspend to ram support for PCIe on J7200 | expand

Commit Message

Thomas Richard May 15, 2024, 10:01 a.m. UTC
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         | 29 +++++++++++++++++++++++++++++
 include/linux/mux/driver.h |  1 +
 2 files changed, 30 insertions(+)
diff mbox series

Patch

diff --git a/drivers/mux/core.c b/drivers/mux/core.c
index 775816112932..0742aa2a7c73 100644
--- a/drivers/mux/core.c
+++ b/drivers/mux/core.c
@@ -215,6 +215,35 @@  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 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");
+			return ret;
+		}
+	}
+
+	return 0;
+}
+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,