diff options
Diffstat (limited to 'drivers/gpu/drm/drm_bridge.c')
| -rw-r--r-- | drivers/gpu/drm/drm_bridge.c | 216 |
1 files changed, 207 insertions, 9 deletions
diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c index fa2794217a90..dd45d9b504d8 100644 --- a/drivers/gpu/drm/drm_bridge.c +++ b/drivers/gpu/drm/drm_bridge.c @@ -21,7 +21,9 @@ * DEALINGS IN THE SOFTWARE. */ +#include <linux/debugfs.h> #include <linux/err.h> +#include <linux/export.h> #include <linux/media-bus-format.h> #include <linux/module.h> #include <linux/mutex.h> @@ -198,13 +200,106 @@ static DEFINE_MUTEX(bridge_lock); static LIST_HEAD(bridge_list); +static void __drm_bridge_free(struct kref *kref) +{ + struct drm_bridge *bridge = container_of(kref, struct drm_bridge, refcount); + + if (bridge->funcs->destroy) + bridge->funcs->destroy(bridge); + kfree(bridge->container); +} + +/** + * drm_bridge_get - Acquire a bridge reference + * @bridge: DRM bridge + * + * This function increments the bridge's refcount. + * + * Returns: + * Pointer to @bridge. + */ +struct drm_bridge *drm_bridge_get(struct drm_bridge *bridge) +{ + if (bridge) + kref_get(&bridge->refcount); + + return bridge; +} +EXPORT_SYMBOL(drm_bridge_get); + +/** + * drm_bridge_put - Release a bridge reference + * @bridge: DRM bridge + * + * This function decrements the bridge's reference count and frees the + * object if the reference count drops to zero. + */ +void drm_bridge_put(struct drm_bridge *bridge) +{ + if (bridge) + kref_put(&bridge->refcount, __drm_bridge_free); +} +EXPORT_SYMBOL(drm_bridge_put); + +/** + * drm_bridge_put_void - wrapper to drm_bridge_put() taking a void pointer + * + * @data: pointer to @struct drm_bridge, cast to a void pointer + * + * Wrapper of drm_bridge_put() to be used when a function taking a void + * pointer is needed, for example as a devm action. + */ +static void drm_bridge_put_void(void *data) +{ + struct drm_bridge *bridge = (struct drm_bridge *)data; + + drm_bridge_put(bridge); +} + +void *__devm_drm_bridge_alloc(struct device *dev, size_t size, size_t offset, + const struct drm_bridge_funcs *funcs) +{ + void *container; + struct drm_bridge *bridge; + int err; + + if (!funcs) { + dev_warn(dev, "Missing funcs pointer\n"); + return ERR_PTR(-EINVAL); + } + + container = kzalloc(size, GFP_KERNEL); + if (!container) + return ERR_PTR(-ENOMEM); + + bridge = container + offset; + bridge->container = container; + bridge->funcs = funcs; + kref_init(&bridge->refcount); + + err = devm_add_action_or_reset(dev, drm_bridge_put_void, bridge); + if (err) + return ERR_PTR(err); + + return container; +} +EXPORT_SYMBOL(__devm_drm_bridge_alloc); + /** * drm_bridge_add - add the given bridge to the global bridge list * * @bridge: bridge control structure + * + * The bridge to be added must have been allocated by + * devm_drm_bridge_alloc(). */ void drm_bridge_add(struct drm_bridge *bridge) { + if (!bridge->container) + DRM_WARN("DRM bridge corrupted or not allocated by devm_drm_bridge_alloc()\n"); + + drm_bridge_get(bridge); + mutex_init(&bridge->hpd_mutex); if (bridge->ops & DRM_BRIDGE_OP_HDMI) @@ -252,6 +347,8 @@ void drm_bridge_remove(struct drm_bridge *bridge) mutex_unlock(&bridge_lock); mutex_destroy(&bridge->hpd_mutex); + + drm_bridge_put(bridge); } EXPORT_SYMBOL(drm_bridge_remove); @@ -280,6 +377,11 @@ static const struct drm_private_state_funcs drm_bridge_priv_state_funcs = { .atomic_destroy_state = drm_bridge_atomic_destroy_priv_state, }; +static bool drm_bridge_is_atomic(struct drm_bridge *bridge) +{ + return bridge->funcs->atomic_reset != NULL; +} + /** * drm_bridge_attach - attach the bridge to an encoder's chain * @@ -312,11 +414,17 @@ int drm_bridge_attach(struct drm_encoder *encoder, struct drm_bridge *bridge, if (!encoder || !bridge) return -EINVAL; - if (previous && (!previous->dev || previous->encoder != encoder)) - return -EINVAL; + drm_bridge_get(bridge); - if (bridge->dev) - return -EBUSY; + if (previous && (!previous->dev || previous->encoder != encoder)) { + ret = -EINVAL; + goto err_put_bridge; + } + + if (bridge->dev) { + ret = -EBUSY; + goto err_put_bridge; + } bridge->dev = encoder->dev; bridge->encoder = encoder; @@ -327,12 +435,12 @@ int drm_bridge_attach(struct drm_encoder *encoder, struct drm_bridge *bridge, list_add(&bridge->chain_node, &encoder->bridge_chain); if (bridge->funcs->attach) { - ret = bridge->funcs->attach(bridge, flags); + ret = bridge->funcs->attach(bridge, encoder, flags); if (ret < 0) goto err_reset_bridge; } - if (bridge->funcs->atomic_reset) { + if (drm_bridge_is_atomic(bridge)) { struct drm_bridge_state *state; state = bridge->funcs->atomic_reset(bridge); @@ -365,6 +473,8 @@ err_reset_bridge: "failed to attach bridge %pOF to encoder %s\n", bridge->of_node, encoder->name); +err_put_bridge: + drm_bridge_put(bridge); return ret; } EXPORT_SYMBOL(drm_bridge_attach); @@ -377,7 +487,7 @@ void drm_bridge_detach(struct drm_bridge *bridge) if (WARN_ON(!bridge->dev)) return; - if (bridge->funcs->atomic_reset) + if (drm_bridge_is_atomic(bridge)) drm_atomic_private_obj_fini(&bridge->base); if (bridge->funcs->detach) @@ -385,6 +495,7 @@ void drm_bridge_detach(struct drm_bridge *bridge) list_del(&bridge->chain_node); bridge->dev = NULL; + drm_bridge_put(bridge); } /** @@ -1126,12 +1237,13 @@ EXPORT_SYMBOL(drm_atomic_bridge_chain_check); * The detection status on success, or connector_status_unknown if the bridge * doesn't support output detection. */ -enum drm_connector_status drm_bridge_detect(struct drm_bridge *bridge) +enum drm_connector_status +drm_bridge_detect(struct drm_bridge *bridge, struct drm_connector *connector) { if (!(bridge->ops & DRM_BRIDGE_OP_DETECT)) return connector_status_unknown; - return bridge->funcs->detect(bridge); + return bridge->funcs->detect(bridge, connector); } EXPORT_SYMBOL_GPL(drm_bridge_detect); @@ -1300,6 +1412,92 @@ struct drm_bridge *of_drm_find_bridge(struct device_node *np) EXPORT_SYMBOL(of_drm_find_bridge); #endif +/** + * devm_drm_put_bridge - Release a bridge reference obtained via devm + * @dev: device that got the bridge via devm + * @bridge: pointer to a struct drm_bridge obtained via devm + * + * Same as drm_bridge_put() for bridge pointers obtained via devm functions + * such as devm_drm_bridge_alloc(). + * + * This function is a temporary workaround and MUST NOT be used. Manual + * handling of bridge lifetime is inherently unsafe. + */ +void devm_drm_put_bridge(struct device *dev, struct drm_bridge *bridge) +{ + devm_release_action(dev, drm_bridge_put_void, bridge); +} +EXPORT_SYMBOL(devm_drm_put_bridge); + +static void drm_bridge_debugfs_show_bridge(struct drm_printer *p, + struct drm_bridge *bridge, + unsigned int idx) +{ + drm_printf(p, "bridge[%u]: %ps\n", idx, bridge->funcs); + drm_printf(p, "\ttype: [%d] %s\n", + bridge->type, + drm_get_connector_type_name(bridge->type)); + + if (bridge->of_node) + drm_printf(p, "\tOF: %pOFfc\n", bridge->of_node); + + drm_printf(p, "\tops: [0x%x]", bridge->ops); + if (bridge->ops & DRM_BRIDGE_OP_DETECT) + drm_puts(p, " detect"); + if (bridge->ops & DRM_BRIDGE_OP_EDID) + drm_puts(p, " edid"); + if (bridge->ops & DRM_BRIDGE_OP_HPD) + drm_puts(p, " hpd"); + if (bridge->ops & DRM_BRIDGE_OP_MODES) + drm_puts(p, " modes"); + if (bridge->ops & DRM_BRIDGE_OP_HDMI) + drm_puts(p, " hdmi"); + drm_puts(p, "\n"); +} + +static int allbridges_show(struct seq_file *m, void *data) +{ + struct drm_printer p = drm_seq_file_printer(m); + struct drm_bridge *bridge; + unsigned int idx = 0; + + mutex_lock(&bridge_lock); + + list_for_each_entry(bridge, &bridge_list, list) + drm_bridge_debugfs_show_bridge(&p, bridge, idx++); + + mutex_unlock(&bridge_lock); + + return 0; +} +DEFINE_SHOW_ATTRIBUTE(allbridges); + +static int encoder_bridges_show(struct seq_file *m, void *data) +{ + struct drm_encoder *encoder = m->private; + struct drm_printer p = drm_seq_file_printer(m); + struct drm_bridge *bridge; + unsigned int idx = 0; + + drm_for_each_bridge_in_chain(encoder, bridge) + drm_bridge_debugfs_show_bridge(&p, bridge, idx++); + + return 0; +} +DEFINE_SHOW_ATTRIBUTE(encoder_bridges); + +void drm_bridge_debugfs_params(struct dentry *root) +{ + debugfs_create_file("bridges", 0444, root, NULL, &allbridges_fops); +} + +void drm_bridge_debugfs_encoder_params(struct dentry *root, + struct drm_encoder *encoder) +{ + /* bridges list */ + debugfs_create_file("bridges", 0444, root, encoder, &encoder_bridges_fops); +} + MODULE_AUTHOR("Ajay Kumar <ajaykumar.rs@samsung.com>"); MODULE_DESCRIPTION("DRM bridge infrastructure"); MODULE_LICENSE("GPL and additional rights"); |