return 0;
}
+/**
+ * drm_atomic_helper_bridge_propagate_bus_fmt() - Propagate output format to
+ * the input end of a bridge
+ * @bridge: bridge control structure
+ * @bridge_state: new bridge state
+ * @crtc_state: new CRTC state
+ * @conn_state: new connector state
+ * @output_fmt: tested output bus format
+ * @num_input_fmts: will contain the size of the returned array
+ *
+ * This helper is a pluggable implementation of the
+ * &drm_bridge_funcs.atomic_get_input_bus_fmts operation for bridges that don't
+ * modify the bus configuration between their input and their output. It
+ * returns an array of input formats with a single element set to @output_fmt.
+ *
+ * RETURNS:
+ * a valid format array of size @num_input_fmts, or NULL if the allocation
+ * failed
+ */
+u32 *
+drm_atomic_helper_bridge_propagate_bus_fmt(struct drm_bridge *bridge,
+ struct drm_bridge_state *bridge_state,
+ struct drm_crtc_state *crtc_state,
+ struct drm_connector_state *conn_state,
+ u32 output_fmt,
+ unsigned int *num_input_fmts)
+{
+ u32 *input_fmts;
+
+ input_fmts = kzalloc(sizeof(*input_fmts), GFP_KERNEL);
+ if (!input_fmts) {
+ *num_input_fmts = 0;
+ return NULL;
+ }
+
+ *num_input_fmts = 1;
+ input_fmts[0] = output_fmt;
+ return input_fmts;
+}
+EXPORT_SYMBOL(drm_atomic_helper_bridge_propagate_bus_fmt);
+
+static int select_bus_fmt_recursive(struct drm_bridge *first_bridge,
+ struct drm_bridge *cur_bridge,
+ struct drm_crtc_state *crtc_state,
+ struct drm_connector_state *conn_state,
+ u32 out_bus_fmt)
+{
+ struct drm_bridge_state *cur_state;
+ unsigned int num_in_bus_fmts, i;
+ struct drm_bridge *prev_bridge;
+ u32 *in_bus_fmts;
+ int ret;
+
+ prev_bridge = drm_bridge_get_prev_bridge(cur_bridge);
+ cur_state = drm_atomic_get_new_bridge_state(crtc_state->state,
+ cur_bridge);
+ if (WARN_ON(!cur_state))
+ return -EINVAL;
+
+ /*
+ * If bus format negotiation is not supported by this bridge, let's
+ * pass MEDIA_BUS_FMT_FIXED to the previous bridge in the chain and
+ * hope that it can handle this situation gracefully (by providing
+ * appropriate default values).
+ */
+ if (!cur_bridge->funcs->atomic_get_input_bus_fmts) {
+ if (cur_bridge != first_bridge) {
+ ret = select_bus_fmt_recursive(first_bridge,
+ prev_bridge, crtc_state,
+ conn_state,
+ MEDIA_BUS_FMT_FIXED);
+ if (ret)
+ return ret;
+ }
+
+ cur_state->input_bus_cfg.format = MEDIA_BUS_FMT_FIXED;
+ cur_state->output_bus_cfg.format = out_bus_fmt;
+ return 0;
+ }
+
+ in_bus_fmts = cur_bridge->funcs->atomic_get_input_bus_fmts(cur_bridge,
+ cur_state,
+ crtc_state,
+ conn_state,
+ out_bus_fmt,
+ &num_in_bus_fmts);
+ if (!num_in_bus_fmts)
+ return -ENOTSUPP;
+ else if (!in_bus_fmts)
+ return -ENOMEM;
+
+ if (first_bridge == cur_bridge) {
+ cur_state->input_bus_cfg.format = in_bus_fmts[0];
+ cur_state->output_bus_cfg.format = out_bus_fmt;
+ kfree(in_bus_fmts);
+ return 0;
+ }
+
+ for (i = 0; i < num_in_bus_fmts; i++) {
+ ret = select_bus_fmt_recursive(first_bridge, prev_bridge,
+ crtc_state, conn_state,
+ in_bus_fmts[i]);
+ if (ret != -ENOTSUPP)
+ break;
+ }
+
+ if (!ret) {
+ cur_state->input_bus_cfg.format = in_bus_fmts[i];
+ cur_state->output_bus_cfg.format = out_bus_fmt;
+ }
+
+ kfree(in_bus_fmts);
+ return ret;
+}
+
+/*
+ * This function is called by &drm_atomic_bridge_chain_check() just before
+ * calling &drm_bridge_funcs.atomic_check() on all elements of the chain.
+ * It performs bus format negotiation between bridge elements. The negotiation
+ * happens in reverse order, starting from the last element in the chain up to
+ * @bridge.
+ *
+ * Negotiation starts by retrieving supported output bus formats on the last
+ * bridge element and testing them one by one. The test is recursive, meaning
+ * that for each tested output format, the whole chain will be walked backward,
+ * and each element will have to choose an input bus format that can be
+ * transcoded to the requested output format. When a bridge element does not
+ * support transcoding into a specific output format -ENOTSUPP is returned and
+ * the next bridge element will have to try a different format. If none of the
+ * combinations worked, -ENOTSUPP is returned and the atomic modeset will fail.
+ *
+ * This implementation is relying on
+ * &drm_bridge_funcs.atomic_get_output_bus_fmts() and
+ * &drm_bridge_funcs.atomic_get_input_bus_fmts() to gather supported
+ * input/output formats.
+ *
+ * When &drm_bridge_funcs.atomic_get_output_bus_fmts() is not implemented by
+ * the last element of the chain, &drm_atomic_bridge_chain_select_bus_fmts()
+ * tries a single format: &drm_connector.display_info.bus_formats[0] if
+ * available, MEDIA_BUS_FMT_FIXED otherwise.
+ *
+ * When &drm_bridge_funcs.atomic_get_input_bus_fmts() is not implemented,
+ * &drm_atomic_bridge_chain_select_bus_fmts() skips the negotiation on the
+ * bridge element that lacks this hook and asks the previous element in the
+ * chain to try MEDIA_BUS_FMT_FIXED. It's up to bridge drivers to decide what
+ * to do in that case (fail if they want to enforce bus format negotiation, or
+ * provide a reasonable default if they need to support pipelines where not
+ * all elements support bus format negotiation).
+ */
+static int
+drm_atomic_bridge_chain_select_bus_fmts(struct drm_bridge *bridge,
+ struct drm_crtc_state *crtc_state,
+ struct drm_connector_state *conn_state)
+{
+ struct drm_connector *conn = conn_state->connector;
+ struct drm_encoder *encoder = bridge->encoder;
+ struct drm_bridge_state *last_bridge_state;
+ unsigned int i, num_out_bus_fmts;
+ struct drm_bridge *last_bridge;
+ u32 *out_bus_fmts;
+ int ret = 0;
+
+ last_bridge = list_last_entry(&encoder->bridge_chain,
+ struct drm_bridge, chain_node);
+ last_bridge_state = drm_atomic_get_new_bridge_state(crtc_state->state,
+ last_bridge);
+ if (WARN_ON(!last_bridge_state))
+ return -EINVAL;
+
+ if (last_bridge->funcs->atomic_get_output_bus_fmts) {
+ const struct drm_bridge_funcs *funcs = last_bridge->funcs;
+
+ out_bus_fmts = funcs->atomic_get_output_bus_fmts(last_bridge,
+ last_bridge_state,
+ crtc_state,
+ conn_state,
+ &num_out_bus_fmts);
+ if (!num_out_bus_fmts)
+ return -ENOTSUPP;
+ else if (!out_bus_fmts)
+ return -ENOMEM;
+ } else {
+ num_out_bus_fmts = 1;
+ out_bus_fmts = kmalloc(sizeof(*out_bus_fmts), GFP_KERNEL);
+ if (!out_bus_fmts)
+ return -ENOMEM;
+
+ if (conn->display_info.num_bus_formats &&
+ conn->display_info.bus_formats)
+ out_bus_fmts[0] = conn->display_info.bus_formats[0];
+ else
+ out_bus_fmts[0] = MEDIA_BUS_FMT_FIXED;
+ }
+
+ for (i = 0; i < num_out_bus_fmts; i++) {
+ ret = select_bus_fmt_recursive(bridge, last_bridge, crtc_state,
+ conn_state, out_bus_fmts[i]);
+ if (ret != -ENOTSUPP)
+ break;
+ }
+
+ kfree(out_bus_fmts);
+
+ return ret;
+}
+
+static void
+drm_atomic_bridge_propagate_bus_flags(struct drm_bridge *bridge,
+ struct drm_connector *conn,
+ struct drm_atomic_state *state)
+{
+ struct drm_bridge_state *bridge_state, *next_bridge_state;
+ struct drm_bridge *next_bridge;
+ u32 output_flags;
+
+ bridge_state = drm_atomic_get_new_bridge_state(state, bridge);
+ next_bridge = drm_bridge_get_next_bridge(bridge);
+
+ /*
+ * Let's try to apply the most common case here, that is, propagate
+ * display_info flags for the last bridge, and propagate the input
+ * flags of the next bridge element to the output end of the current
+ * bridge when the bridge is not the last one.
+ * There are exceptions to this rule, like when signal inversion is
+ * happening at the board level, but that's something drivers can deal
+ * with from their &drm_bridge_funcs.atomic_check() implementation by
+ * simply overriding the flags value we've set here.
+ */
+ if (!next_bridge) {
+ output_flags = conn->display_info.bus_flags;
+ } else {
+ next_bridge_state = drm_atomic_get_new_bridge_state(state,
+ next_bridge);
+ output_flags = next_bridge_state->input_bus_cfg.flags;
+ }
+
+ bridge_state->output_bus_cfg.flags = output_flags;
+
+ /*
+ * Propage the output flags to the input end of the bridge. Again, it's
+ * not necessarily what all bridges want, but that's what most of them
+ * do, and by doing that by default we avoid forcing drivers to
+ * duplicate the "dummy propagation" logic.
+ */
+ bridge_state->input_bus_cfg.flags = output_flags;
+}
+
/**
* drm_atomic_bridge_chain_check() - Do an atomic check on the bridge chain
* @bridge: bridge control structure
* @crtc_state: new CRTC state
* @conn_state: new connector state
*
- * Calls &drm_bridge_funcs.atomic_check() (falls back on
+ * First trigger a bus format negotiation before calling
+ * &drm_bridge_funcs.atomic_check() (falls back on
* &drm_bridge_funcs.mode_fixup()) op for all the bridges in the encoder chain,
* starting from the last bridge to the first. These are called before calling
* &drm_encoder_helper_funcs.atomic_check()
struct drm_crtc_state *crtc_state,
struct drm_connector_state *conn_state)
{
+ struct drm_connector *conn = conn_state->connector;
struct drm_encoder *encoder = bridge->encoder;
struct drm_bridge *iter;
+ int ret;
+
+ ret = drm_atomic_bridge_chain_select_bus_fmts(bridge, crtc_state,
+ conn_state);
+ if (ret)
+ return ret;
list_for_each_entry_reverse(iter, &encoder->bridge_chain, chain_node) {
int ret;
+ /*
+ * Bus flags are propagated by default. If a bridge needs to
+ * tweak the input bus flags for any reason, it should happen
+ * in its &drm_bridge_funcs.atomic_check() implementation such
+ * that preceding bridges in the chain can propagate the new
+ * bus flags.
+ */
+ drm_atomic_bridge_propagate_bus_flags(iter, conn,
+ crtc_state->state);
+
ret = drm_atomic_bridge_check(iter, crtc_state, conn_state);
if (ret)
return ret;
struct drm_bridge_timings;
struct drm_panel;
+/**
+ * struct drm_bus_cfg - bus configuration
+ *
+ * This structure stores the configuration of a physical bus between two
+ * components in an output pipeline, usually between two bridges, an encoder
+ * and a bridge, or a bridge and a connector.
+ *
+ * The bus configuration is stored in &drm_bridge_state separately for the
+ * input and output buses, as seen from the point of view of each bridge. The
+ * bus configuration of a bridge output is usually identical to the
+ * configuration of the next bridge's input, but may differ if the signals are
+ * modified between the two bridges, for instance by an inverter on the board.
+ * The input and output configurations of a bridge may differ if the bridge
+ * modifies the signals internally, for instance by performing format
+ * conversion, or modifying signals polarities.
+ */
+struct drm_bus_cfg {
+ /**
+ * @format: format used on this bus (one of the MEDIA_BUS_FMT_* format)
+ *
+ * This field should not be directly modified by drivers
+ * (&drm_atomic_bridge_chain_select_bus_fmts() takes care of the bus
+ * format negotiation).
+ */
+ u32 format;
+
+ /**
+ * @flags: DRM_BUS_* flags used on this bus
+ */
+ u32 flags;
+};
+
/**
* struct drm_bridge_state - Atomic bridge state object
* @base: inherit from &drm_private_state
struct drm_private_state base;
struct drm_bridge *bridge;
+
+ /**
+ * @input_bus_cfg: input bus configuration
+ */
+ struct drm_bus_cfg input_bus_cfg;
+
+ /**
+ * @output_bus_cfg: input bus configuration
+ */
+ struct drm_bus_cfg output_bus_cfg;
};
static inline struct drm_bridge_state *
void (*atomic_destroy_state)(struct drm_bridge *bridge,
struct drm_bridge_state *state);
+ /**
+ * @atomic_get_output_bus_fmts:
+ *
+ * Return the supported bus formats on the output end of a bridge.
+ * The returned array must be allocated with kmalloc() and will be
+ * freed by the caller. If the allocation fails, NULL should be
+ * returned. num_output_fmts must be set to the returned array size.
+ * Formats listed in the returned array should be listed in decreasing
+ * preference order (the core will try all formats until it finds one
+ * that works).
+ *
+ * This method is only called on the last element of the bridge chain
+ * as part of the bus format negotiation process that happens in
+ * &drm_atomic_bridge_chain_select_bus_fmts().
+ * This method is optional. When not implemented, the core will
+ * fall back to &drm_connector.display_info.bus_formats[0] if
+ * &drm_connector.display_info.num_bus_formats > 0,
+ * or to MEDIA_BUS_FMT_FIXED otherwise.
+ */
+ u32 *(*atomic_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);
+
+ /**
+ * @atomic_get_input_bus_fmts:
+ *
+ * Return the supported bus formats on the input end of a bridge for
+ * a specific output bus format.
+ *
+ * The returned array must be allocated with kmalloc() and will be
+ * freed by the caller. If the allocation fails, NULL should be
+ * returned. num_output_fmts must be set to the returned array size.
+ * Formats listed in the returned array should be listed in decreasing
+ * preference order (the core will try all formats until it finds one
+ * that works). When the format is not supported NULL should be
+ * returned and *num_output_fmts should be set to 0.
+ *
+ * This method is called on all elements of the bridge chain as part of
+ * the bus format negotiation process that happens in
+ * &drm_atomic_bridge_chain_select_bus_fmts().
+ * This method is optional. When not implemented, the core will bypass
+ * bus format negotiation on this element of the bridge without
+ * failing, and the previous element in the chain will be passed
+ * MEDIA_BUS_FMT_FIXED as its output bus format.
+ *
+ * Bridge drivers that need to support being linked to bridges that are
+ * not supporting bus format negotiation should handle the
+ * output_fmt == MEDIA_BUS_FMT_FIXED case appropriately, by selecting a
+ * sensible default value or extracting this information from somewhere
+ * else (FW property, &drm_display_mode, &drm_display_info, ...)
+ *
+ * Note: Even if input format selection on the first bridge has no
+ * impact on the negotiation process (bus format negotiation stops once
+ * we reach the first element of the chain), drivers are expected to
+ * return accurate input formats as the input format may be used to
+ * configure the CRTC output appropriately.
+ */
+ u32 *(*atomic_get_input_bus_fmts)(struct drm_bridge *bridge,
+ struct drm_bridge_state *bridge_state,
+ struct drm_crtc_state *crtc_state,
+ struct drm_connector_state *conn_state,
+ u32 output_fmt,
+ unsigned int *num_input_fmts);
+
/**
* @atomic_check:
*
* called when &drm_bridge_funcs.atomic_check() is implemented, so only
* one of them should be provided.
*
+ * If drivers need to tweak &drm_bridge_state.input_bus_cfg.flags or
+ * &drm_bridge_state.output_bus_cfg.flags it should should happen in
+ * this function. By default the &drm_bridge_state.output_bus_cfg.flags
+ * field is set to the next bridge
+ * &drm_bridge_state.input_bus_cfg.flags value or
+ * &drm_connector.display_info.bus_flags if the bridge is the last
+ * element in the chain.
+ *
* RETURNS:
* zero if the check passed, a negative error code otherwise.
*/
void drm_atomic_bridge_chain_enable(struct drm_bridge *bridge,
struct drm_atomic_state *state);
+u32 *
+drm_atomic_helper_bridge_propagate_bus_fmt(struct drm_bridge *bridge,
+ struct drm_bridge_state *bridge_state,
+ struct drm_crtc_state *crtc_state,
+ struct drm_connector_state *conn_state,
+ u32 output_fmt,
+ unsigned int *num_input_fmts);
+
void __drm_atomic_helper_bridge_reset(struct drm_bridge *bridge,
struct drm_bridge_state *state);
void __drm_atomic_helper_bridge_duplicate_state(struct drm_bridge *bridge,
projects / openwrt / staging / blogic.git / commitdiff