[PATCH RFC 1/6] phy: core: Add MIPI C-PHY configurations

[Nihal Kumar Gupta <nihal.gupta@oss.qualcomm.com>]

MIPI CSI-2 receivers can be connected through C-PHY as well as D-PHY.
C-PHY uses trios instead of lanes and needs mode-specific timings passed
to the PHY provider.

Add PHY_MODE_MIPI_CPHY and C-PHY configure option carrying the link rate,
trio count and C-PHY prepare/preamble timing.

Signed-off-by: Nihal Kumar Gupta <nihal.gupta@oss.qualcomm.com>
---
 include/linux/phy/phy.h | 47 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 47 insertions(+)

diff --git a/include/linux/phy/phy.h b/include/linux/phy/phy.h
index c480d6cb42c500a295eef3bdf42fbc6d36f54bf8..c3784b679f3a26686324286d407cfa9d258579f1 100644
--- a/include/linux/phy/phy.h
+++ b/include/linux/phy/phy.h
@@ -47,6 +47,7 @@ enum phy_mode {
 	PHY_MODE_DP,
 	PHY_MODE_HDMI,
 	PHY_MODE_TBT,
+	PHY_MODE_MIPI_CPHY,
 };
 
 enum phy_media {
@@ -64,11 +65,56 @@ union phy_notify {
 	enum phy_ufs_state ufs_state;
 };
 
+/**
+ * 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 per trio, in symbols per second.
+	 */
+	u64 symbol_rate;
+
+	/**
+	 * @trios:
+	 *
+	 * Number of active C-PHY trios.
+	 *
+	 * Minimum value: 1
+	 * Maximum value: 3
+	 */
+	unsigned int trios;
+
+	/**
+	 * @t_prepare_ns:
+	 *
+	 * C-PHY T_PREPARE timing value, in nanoseconds.
+	 * Time the transmitter drives the LP-00 state before
+	 * starting the HS preamble sequence.
+	 */
+	u32 t_prepare_ns;
+
+	/**
+	 * @t_preamble_ns:
+	 *
+	 * C-PHY T_PREAMBLE timing value, in nanoseconds.
+	 * Duration of the HS preamble sequence transmitted
+	 * before the first payload symbol.
+	 */
+	u32 t_preamble_ns;
+};
+
 /**
  * union phy_configure_opts - Opaque generic phy configuration
  *
  * @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 +124,7 @@ 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;

-- 
2.34.1