The atomic_get_output_bus_fmts callback is used by the DRM bridge layer to recursively select a suitable output format in a bridge chain.
As a bridge that outputs to HDMI, dw-hdmi-qp will have its output formats determined by which formats the platform-specific integration of the hardware supports, and the chosen HDMI output bit depth. Implement this callback. The returned u32* buffer is supposed to be freed by the caller of this callback, as specified by the callback's documentation. Signed-off-by: Nicolas Frattaroli <[email protected]> --- drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c | 64 ++++++++++++++++++++++++++++ 1 file changed, 64 insertions(+) diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c index ab7fed6214e0..82a63964f7f7 100644 --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c @@ -11,6 +11,7 @@ #include <linux/export.h> #include <linux/i2c.h> #include <linux/irq.h> +#include <linux/media-bus-format.h> #include <linux/module.h> #include <linux/mutex.h> #include <linux/of.h> @@ -862,6 +863,68 @@ static int dw_hdmi_qp_config_audio_infoframe(struct dw_hdmi_qp *hdmi, return 0; } +static u32* +dw_hdmi_qp_bridge_get_output_bus_fmts(struct drm_bridge *bridge, + struct drm_bridge_state *bridge_state, + struct drm_crtc_state *crtc_state, + struct drm_connector_state *conn_state, + unsigned int *num_output_fmts) +{ + unsigned int num_fmts = 0; + u32 *out_fmts; + + /* + * bridge->supported_formats is a bit field of the HDMI_COLORSPACE_* enums. + * These enums are defined by the HDMI standard, and currently top out at + * 7. Consequently, BIT(7) is the highest bit that will be set here, unless + * the standard runs out of reserved pixel formats. Therefore, hweight8() + * will give an accurate count of how many bus formats we'll output. + */ + out_fmts = kmalloc_array(hweight8(bridge->supported_formats), sizeof(u32), + GFP_KERNEL); + if (!out_fmts) { + *num_output_fmts = 0; + return NULL; + } + + switch (conn_state->hdmi.output_bpc) { + case 12: + if (bridge->supported_formats & BIT(HDMI_COLORSPACE_RGB)) + out_fmts[num_fmts++] = MEDIA_BUS_FMT_RGB121212_1X36; + if (bridge->supported_formats & BIT(HDMI_COLORSPACE_YUV444)) + out_fmts[num_fmts++] = MEDIA_BUS_FMT_YUV12_1X36; + if (bridge->supported_formats & BIT(HDMI_COLORSPACE_YUV422)) + out_fmts[num_fmts++] = MEDIA_BUS_FMT_UYVY12_1X24; + if (bridge->supported_formats & BIT(HDMI_COLORSPACE_YUV420)) + out_fmts[num_fmts++] = MEDIA_BUS_FMT_UYYVYY12_0_5X36; + break; + case 10: + if (bridge->supported_formats & BIT(HDMI_COLORSPACE_RGB)) + out_fmts[num_fmts++] = MEDIA_BUS_FMT_RGB101010_1X30; + if (bridge->supported_formats & BIT(HDMI_COLORSPACE_YUV444)) + out_fmts[num_fmts++] = MEDIA_BUS_FMT_YUV10_1X30; + if (bridge->supported_formats & BIT(HDMI_COLORSPACE_YUV422)) + out_fmts[num_fmts++] = MEDIA_BUS_FMT_UYVY10_1X20; + if (bridge->supported_formats & BIT(HDMI_COLORSPACE_YUV420)) + out_fmts[num_fmts++] = MEDIA_BUS_FMT_UYYVYY10_0_5X30; + break; + default: + if (bridge->supported_formats & BIT(HDMI_COLORSPACE_RGB)) + out_fmts[num_fmts++] = MEDIA_BUS_FMT_RGB888_1X24; + if (bridge->supported_formats & BIT(HDMI_COLORSPACE_YUV444)) + out_fmts[num_fmts++] = MEDIA_BUS_FMT_YUV8_1X24; + if (bridge->supported_formats & BIT(HDMI_COLORSPACE_YUV422)) + out_fmts[num_fmts++] = MEDIA_BUS_FMT_UYVY8_1X16; + if (bridge->supported_formats & BIT(HDMI_COLORSPACE_YUV420)) + out_fmts[num_fmts++] = MEDIA_BUS_FMT_UYYVYY8_0_5X24; + break; + } + + *num_output_fmts = num_fmts; + + return out_fmts; +} + static void dw_hdmi_qp_bridge_atomic_enable(struct drm_bridge *bridge, struct drm_atomic_state *state) { @@ -1213,6 +1276,7 @@ static int dw_hdmi_qp_cec_transmit(struct drm_bridge *bridge, u8 attempts, #endif /* CONFIG_DRM_DW_HDMI_QP_CEC */ static const struct drm_bridge_funcs dw_hdmi_qp_bridge_funcs = { + .atomic_get_output_bus_fmts = dw_hdmi_qp_bridge_get_output_bus_fmts, .atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state, .atomic_destroy_state = drm_atomic_helper_bridge_destroy_state, .atomic_reset = drm_atomic_helper_bridge_reset, -- 2.52.0
