[PATCH RFC 1/4] phy: Add MIPI C-PHY mode and configuration options

[George Neacsu <geocausa@gmail.com>]

The generic PHY framework has a mode and configuration options for MIPI
D-PHY but none for C-PHY, so a CSI-2 receiver has no way to ask a PHY
that does both for C-PHY. Add PHY_MODE_MIPI_CPHY and struct
phy_configure_opts_mipi_cphy. The options are the two values a receiver
knows: the symbol rate on each trio and the number of trios.

The first user is the Qualcomm CSI2 PHY, whose X1E80100 instances carry
the C-PHY front camera of the Surface Pro 11.

Assisted-by: Claude:claude-opus-5-5
Signed-off-by: George Neacsu <geocausa@gmail.com>
---
 include/linux/phy/phy-mipi-cphy.h | 27 +++++++++++++++++++++++++++
 include/linux/phy/phy.h           |  5 +++++
 2 files changed, 32 insertions(+)

diff --git a/include/linux/phy/phy-mipi-cphy.h b/include/linux/phy/phy-mipi-cphy.h
new file mode 100644
index 000000000..e3f0a8257
--- /dev/null
+++ b/include/linux/phy/phy-mipi-cphy.h
@@ -0,0 +1,27 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __PHY_MIPI_CPHY_H_
+#define __PHY_MIPI_CPHY_H_
+
+/**
+ * struct phy_configure_opts_mipi_cphy - MIPI C-PHY configuration set
+ *
+ * This structure is used to represent the configuration state of a
+ * MIPI C-PHY phy.
+ */
+struct phy_configure_opts_mipi_cphy {
+	/**
+	 * @symbol_rate:
+	 *
+	 * Symbol rate on each trio, in symbols per second.
+	 */
+	unsigned long		symbol_rate;
+
+	/**
+	 * @lanes:
+	 *
+	 * Number of active trios.
+	 */
+	unsigned char		lanes;
+};
+
+#endif /* __PHY_MIPI_CPHY_H_ */
diff --git a/include/linux/phy/phy.h b/include/linux/phy/phy.h
index c480d6cb4..f12337834 100644
--- a/include/linux/phy/phy.h
+++ b/include/linux/phy/phy.h
@@ -19,6 +19,7 @@
 #include <linux/phy/phy-dp.h>
 #include <linux/phy/phy-hdmi.h>
 #include <linux/phy/phy-lvds.h>
+#include <linux/phy/phy-mipi-cphy.h>
 #include <linux/phy/phy-mipi-dphy.h>
 #include <linux/phy/phy-thunderbolt.h>
 
@@ -42,6 +43,7 @@ enum phy_mode {
 	PHY_MODE_PCIE,
 	PHY_MODE_ETHERNET,
 	PHY_MODE_MIPI_DPHY,
+	PHY_MODE_MIPI_CPHY,
 	PHY_MODE_SATA,
 	PHY_MODE_LVDS,
 	PHY_MODE_DP,
@@ -69,6 +71,8 @@ union phy_notify {
  *
  * @mipi_dphy:	Configuration set applicable for phys supporting
  *		the MIPI_DPHY phy mode.
+ * @mipi_cphy:	Configuration set applicable for phys supporting
+ *		the MIPI_CPHY phy mode.
  * @dp:		Configuration set applicable for phys supporting
  *		the DisplayPort protocol.
  * @lvds:	Configuration set applicable for phys supporting
@@ -78,6 +82,7 @@ union phy_notify {
  */
 union phy_configure_opts {
 	struct phy_configure_opts_mipi_dphy	mipi_dphy;
+	struct phy_configure_opts_mipi_cphy	mipi_cphy;
 	struct phy_configure_opts_dp		dp;
 	struct phy_configure_opts_lvds		lvds;
 	struct phy_configure_opts_hdmi		hdmi;

-- 
2.53.0