drm/bridge/synopsys: dsi: driver-specific configuration of phy timings

The timing values for dw-dsi are often dependent on the used display and
according to Philippe Cornu will most likely also depend on the used phy
technology in the soc-specific implementation.

To solve this and allow specific implementations to define them as needed
add a new get_timing callback to phy_ops and call this from the dphy_timing
function to retrieve the necessary values for the specific mode.

Right now this handles the hs2lp + lp2hs where Rockchip SoCs need handling
according to the phy speed, while STM seems to be ok with static values.

changes in v5:
- rebase on 5.5-rc1
- merge into px30 dsi series to prevent ordering conflicts

changes in v4:
- rebase to make it directly fit on top of drm-misc-next after all

changes in v3:
- check existence of phy_ops->get_timing in __dw_mipi_dsi_probe()
- emit actual error when get_timing() call fails
- add tags from Philippe and Yannick

changes in v2:
- add driver-specific handling, don't force all bridge users to use
  the same timings, as suggested by Philippe

Suggested-by: Philippe Cornu <philippe.cornu@st.com>
Signed-off-by: Heiko Stuebner <heiko.stuebner@theobroma-systems.com>
Reviewed-by: Philippe Cornu <philippe.cornu@st.com>
Tested-by: Yannick Fertre <yannick.fertre@st.com>
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191209143130.4553-2-heiko@sntech.de

1 files changed, 9 insertions, 0 deletions

diff --git a/include/drm/bridge/dw_mipi_dsi.h b/include/drm/bridge/dw_mipi_dsi.h
index 94cc64a342e1..b0e390b3288e 100644
--- a/include/drm/bridge/dw_mipi_dsi.h
+++ b/include/drm/bridge/dw_mipi_dsi.h
@@ -19,6 +19,13 @@ struct dw_mipi_dsi;
 struct mipi_dsi_device;
 struct platform_device;
 
+struct dw_mipi_dsi_dphy_timing {
+	u16 data_hs2lp;
+	u16 data_lp2hs;
+	u16 clk_hs2lp;
+	u16 clk_lp2hs;
+};
+
 struct dw_mipi_dsi_phy_ops {
 	int (*init)(void *priv_data);
 	void (*power_on)(void *priv_data);
@@ -27,6 +34,8 @@ struct dw_mipi_dsi_phy_ops {
 			     const struct drm_display_mode *mode,
 			     unsigned long mode_flags, u32 lanes, u32 format,
 			     unsigned int *lane_mbps);
+	int (*get_timing)(void *priv_data, unsigned int lane_mbps,
+			  struct dw_mipi_dsi_dphy_timing *timing);
 };
 
 struct dw_mipi_dsi_host_ops {