The A20 and other SoC with two TCONs (A31, R40, etc.) can use its second TCON as the secondary LVDS link in a dual-link setup, with the TCON0 being the main link. Extend a bit the parsing code to leverage the DRM dual-link code, register only the LVDS output on the primary TCON, and add the needed bits to setup the TCON properly.
Reviewed-by: Chen-Yu Tsai wens@csie.org Signed-off-by: Maxime Ripard maxime@cerno.tech --- drivers/gpu/drm/sun4i/sun4i_tcon.c | 36 ++++++++++++++++++++++++++++++ drivers/gpu/drm/sun4i/sun4i_tcon.h | 4 ++++ 2 files changed, 40 insertions(+)
diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.c b/drivers/gpu/drm/sun4i/sun4i_tcon.c index 32757175f86b..005c37831eb6 100644 --- a/drivers/gpu/drm/sun4i/sun4i_tcon.c +++ b/drivers/gpu/drm/sun4i/sun4i_tcon.c @@ -475,6 +475,10 @@ static void sun4i_tcon0_mode_set_lvds(struct sun4i_tcon *tcon, SUN4I_TCON0_BASIC2_V_BACKPORCH(bp));
reg = SUN4I_TCON0_LVDS_IF_CLK_SEL_TCON0; + + if (tcon->lvds_dual_link) + reg |= SUN4I_TCON0_LVDS_IF_DUAL_LINK; + if (sun4i_tcon_get_pixel_depth(encoder) == 24) reg |= SUN4I_TCON0_LVDS_IF_BITWIDTH_24BITS; else @@ -903,6 +907,16 @@ static int sun4i_tcon_register_panel(struct drm_device *drm, !of_device_is_compatible(remote, "panel-lvds")) return sun4i_rgb_init(drm, tcon);
+ /* + * Only the TCON0 will be relevant for the LVDS output, so if + * our ID is something else, let's prevent our TCON from + * registering its own LVDS output + */ + if (tcon->id) { + dev_dbg(dev, "TCON used as an LVDS secondary link."); + return 0; + } + /* * This can only be made optional since we've had DT * nodes without the LVDS reset properties. @@ -939,6 +953,28 @@ static int sun4i_tcon_register_panel(struct drm_device *drm, } }
+ /* + * If we don't have a second TCON, we will never be able to do + * dual-link LVDS, so we don't have much more to do. + */ + companion = of_parse_phandle(dev->of_node, "link-companion", 0); + if (!companion) + return sun4i_lvds_init(drm, tcon); + + /* + * Let's do a sanity check on the dual-link setup to make sure + * everything is properly described. + */ + ret = drm_of_lvds_get_dual_link_pixel_order(dev->of_node, 1, 0, + companion, 1, 0); + if (ret < 0) { + dev_err(dev, "Invalid Dual-Link Configuration.\n"); + return ret; + } + + dev_info(dev, "Primary TCON, enabling LVDS Dual-Link"); + tcon->lvds_dual_link = true; + return sun4i_lvds_init(drm, tcon); }
diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.h b/drivers/gpu/drm/sun4i/sun4i_tcon.h index ee555318e3c2..f6a589828f94 100644 --- a/drivers/gpu/drm/sun4i/sun4i_tcon.h +++ b/drivers/gpu/drm/sun4i/sun4i_tcon.h @@ -98,6 +98,7 @@
#define SUN4I_TCON0_LVDS_IF_REG 0x84 #define SUN4I_TCON0_LVDS_IF_EN BIT(31) +#define SUN4I_TCON0_LVDS_IF_DUAL_LINK BIT(30) #define SUN4I_TCON0_LVDS_IF_BITWIDTH_MASK BIT(26) #define SUN4I_TCON0_LVDS_IF_BITWIDTH_18BITS (1 << 26) #define SUN4I_TCON0_LVDS_IF_BITWIDTH_24BITS (0 << 26) @@ -280,6 +281,9 @@ struct sun4i_tcon { /* Associated crtc */ struct sun4i_crtc *crtc;
+ /* Is the LVDS link a dual-channel link? */ + bool lvds_dual_link; + int id;
/* TCON list management */