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[v4,01/15] docs: phy: Add a part about PHY mode and submode

Message ID 20201231142948.3241780-2-paul.kocialkowski@bootlin.com
State Superseded
Headers show
Series Allwinner MIPI CSI-2 support for A31/V3s/A83T | expand

Commit Message

Paul Kocialkowski Dec. 31, 2020, 2:29 p.m. UTC 
Besides giving pointers to the relevant functions for PHY mode and
submode configuration, this clarifies the need to set them before
powering on the PHY.

Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
Reviewed-by: Maxime Ripard <mripard@kernel.org>
---
 Documentation/driver-api/phy/phy.rst | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)
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Patch

diff --git a/Documentation/driver-api/phy/phy.rst b/Documentation/driver-api/phy/phy.rst
index 8fc1ce0bb905..6cbc72707a49 100644
--- a/Documentation/driver-api/phy/phy.rst
+++ b/Documentation/driver-api/phy/phy.rst
@@ -195,3 +195,21 @@  DeviceTree Binding
 
 The documentation for PHY dt binding can be found @
 Documentation/devicetree/bindings/phy/phy-bindings.txt
+
+PHY Mode and Submode
+====================
+
+Once a reference to a PHY is obtained by a controller, the PHY can be configured
+to a PHY mode and submode. PHY modes are described in the `phy_mode` enum while
+submodes are specific to the selected PHY mode.
+
+Mode and submode configuration is done by calling::
+
+	int phy_set_mode_ext(struct phy *phy, enum phy_mode mode, int submode);
+
+If no submode is to be configured, users can call::
+
+	int phy_set_mode(struct phy *phy, enum phy_mode mode);
+
+The PHY mode and submode must not be configured after the PHY has already been
+powered on.