[PATCH v2] drm/amd/display: add CEC notifier to amdgpu driver

Mario Limonciello mario.limonciello at amd.com
Tue Jan 7 16:10:55 UTC 2025


On 1/7/2025 06:08, Kun Liu wrote:
> This patch adds the cec_notifier feature to amdgpu driver.
> The changes will allow amdgpu driver code to notify EDID
> and HPD changes to an eventual CEC adapter.
> 
> Signed-off-by: Kun Liu <Kun.Liu2 at amd.com>

Reviewed-by: Mario Limonciello <mario.limonciello at amd.com>

> ---
>   drivers/gpu/drm/amd/display/Kconfig           |  2 +
>   .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 76 +++++++++++++++++++
>   .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h |  6 ++
>   .../amd/display/amdgpu_dm/amdgpu_dm_debugfs.c | 66 +++++++++++++++-
>   drivers/gpu/drm/amd/include/amd_shared.h      |  5 ++
>   5 files changed, 154 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/amd/display/Kconfig b/drivers/gpu/drm/amd/display/Kconfig
> index 11e3f2f3b..abd3b6564 100644
> --- a/drivers/gpu/drm/amd/display/Kconfig
> +++ b/drivers/gpu/drm/amd/display/Kconfig
> @@ -8,6 +8,8 @@ config DRM_AMD_DC
>   	bool "AMD DC - Enable new display engine"
>   	default y
>   	depends on BROKEN || !CC_IS_CLANG || ARM64 || LOONGARCH || RISCV || SPARC64 || X86_64
> +	select CEC_CORE
> +	select CEC_NOTIFIER
>   	select SND_HDA_COMPONENT if SND_HDA_CORE
>   	# !CC_IS_CLANG: https://github.com/ClangBuiltLinux/linux/issues/1752
>   	select DRM_AMD_DC_FP if ARCH_HAS_KERNEL_FPU_SUPPORT && !(CC_IS_CLANG && (ARM64 || LOONGARCH || RISCV))
> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> index 49baef9dd..1db955c28 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> @@ -97,6 +97,7 @@
>   #include <drm/drm_audio_component.h>
>   #include <drm/drm_gem_atomic_helper.h>
>   
> +#include <media/cec-notifier.h>
>   #include <acpi/video.h>
>   
>   #include "ivsrcid/dcn/irqsrcs_dcn_1_0.h"
> @@ -2751,6 +2752,48 @@ static void resume_mst_branch_status(struct drm_dp_mst_topology_mgr *mgr)
>   	mutex_unlock(&mgr->lock);
>   }
>   
> +void hdmi_cec_unset_edid(struct amdgpu_dm_connector *aconnector)
> +{
> +	struct cec_notifier *n = aconnector->notifier;
> +
> +	if (!n)
> +		return;
> +
> +	cec_notifier_phys_addr_invalidate(n);
> +}
> +
> +void hdmi_cec_set_edid(struct amdgpu_dm_connector *aconnector)
> +{
> +	struct drm_connector *connector = &aconnector->base;
> +	struct cec_notifier *n = aconnector->notifier;
> +
> +	if (!n)
> +		return;
> +
> +	cec_notifier_set_phys_addr(n,
> +				   connector->display_info.source_physical_address);
> +}
> +
> +static void s3_handle_hdmi_cec(struct drm_device *ddev, bool suspend)
> +{
> +	struct amdgpu_dm_connector *aconnector;
> +	struct drm_connector *connector;
> +	struct drm_connector_list_iter conn_iter;
> +
> +	drm_connector_list_iter_begin(ddev, &conn_iter);
> +	drm_for_each_connector_iter(connector, &conn_iter) {
> +		if (connector->connector_type == DRM_MODE_CONNECTOR_WRITEBACK)
> +			continue;
> +
> +		aconnector = to_amdgpu_dm_connector(connector);
> +		if (suspend)
> +			hdmi_cec_unset_edid(aconnector);
> +		else
> +			hdmi_cec_set_edid(aconnector);
> +	}
> +	drm_connector_list_iter_end(&conn_iter);
> +}
> +
>   static void s3_handle_mst(struct drm_device *dev, bool suspend)
>   {
>   	struct amdgpu_dm_connector *aconnector;
> @@ -3022,6 +3065,8 @@ static int dm_suspend(struct amdgpu_ip_block *ip_block)
>   	if (IS_ERR(adev->dm.cached_state))
>   		return PTR_ERR(adev->dm.cached_state);
>   
> +	s3_handle_hdmi_cec(adev_to_drm(adev), true);
> +
>   	s3_handle_mst(adev_to_drm(adev), true);
>   
>   	amdgpu_dm_irq_suspend(adev);
> @@ -3294,6 +3339,8 @@ static int dm_resume(struct amdgpu_ip_block *ip_block)
>   	 */
>   	amdgpu_dm_irq_resume_early(adev);
>   
> +	s3_handle_hdmi_cec(ddev, false);
> +
>   	/* On resume we need to rewrite the MSTM control bits to enable MST*/
>   	s3_handle_mst(ddev, false);
>   
> @@ -3603,6 +3650,7 @@ void amdgpu_dm_update_connector_after_detect(
>   		dc_sink_retain(aconnector->dc_sink);
>   		if (sink->dc_edid.length == 0) {
>   			aconnector->drm_edid = NULL;
> +			hdmi_cec_unset_edid(aconnector);
>   			if (aconnector->dc_link->aux_mode) {
>   				drm_dp_cec_unset_edid(&aconnector->dm_dp_aux.aux);
>   			}
> @@ -3612,6 +3660,7 @@ void amdgpu_dm_update_connector_after_detect(
>   			aconnector->drm_edid = drm_edid_alloc(edid, sink->dc_edid.length);
>   			drm_edid_connector_update(connector, aconnector->drm_edid);
>   
> +			hdmi_cec_set_edid(aconnector);
>   			if (aconnector->dc_link->aux_mode)
>   				drm_dp_cec_attach(&aconnector->dm_dp_aux.aux,
>   						  connector->display_info.source_physical_address);
> @@ -3628,6 +3677,7 @@ void amdgpu_dm_update_connector_after_detect(
>   		amdgpu_dm_update_freesync_caps(connector, aconnector->drm_edid);
>   		update_connector_ext_caps(aconnector);
>   	} else {
> +		hdmi_cec_unset_edid(aconnector);
>   		drm_dp_cec_unset_edid(&aconnector->dm_dp_aux.aux);
>   		amdgpu_dm_update_freesync_caps(connector, NULL);
>   		aconnector->num_modes = 0;
> @@ -7044,6 +7094,7 @@ static void amdgpu_dm_connector_unregister(struct drm_connector *connector)
>   	if (amdgpu_dm_should_create_sysfs(amdgpu_dm_connector))
>   		sysfs_remove_group(&connector->kdev->kobj, &amdgpu_group);
>   
> +	cec_notifier_conn_unregister(amdgpu_dm_connector->notifier);
>   	drm_dp_aux_unregister(&amdgpu_dm_connector->dm_dp_aux.aux);
>   }
>   
> @@ -8280,6 +8331,27 @@ create_i2c(struct ddc_service *ddc_service,
>   	return i2c;
>   }
>   
> +int amdgpu_dm_initialize_hdmi_connector(struct amdgpu_dm_connector *aconnector)
> +{
> +	struct cec_connector_info conn_info;
> +	struct drm_device *ddev = aconnector->base.dev;
> +	struct device *hdmi_dev = ddev->dev;
> +
> +	if (amdgpu_dc_debug_mask & DC_DISABLE_HDMI_CEC) {
> +		drm_info(ddev, "HDMI-CEC feature masked\n");
> +		return -EINVAL;
> +	}
> +
> +	cec_fill_conn_info_from_drm(&conn_info, &aconnector->base);
> +	aconnector->notifier =
> +		cec_notifier_conn_register(hdmi_dev, NULL, &conn_info);
> +	if (!aconnector->notifier) {
> +		drm_err(ddev, "Failed to create cec notifier\n");
> +		return -ENOMEM;
> +	}
> +
> +	return 0;
> +}
>   
>   /*
>    * Note: this function assumes that dc_link_detect() was called for the
> @@ -8343,6 +8415,10 @@ static int amdgpu_dm_connector_init(struct amdgpu_display_manager *dm,
>   	drm_connector_attach_encoder(
>   		&aconnector->base, &aencoder->base);
>   
> +	if (connector_type == DRM_MODE_CONNECTOR_HDMIA ||
> +	    connector_type == DRM_MODE_CONNECTOR_HDMIB)
> +		amdgpu_dm_initialize_hdmi_connector(aconnector);
> +
>   	if (connector_type == DRM_MODE_CONNECTOR_DisplayPort
>   		|| connector_type == DRM_MODE_CONNECTOR_eDP)
>   		amdgpu_dm_initialize_dp_connector(dm, aconnector, link->link_index);
> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
> index e46e1365f..76fa3e785 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
> @@ -671,6 +671,8 @@ struct amdgpu_dm_connector {
>   	uint32_t connector_id;
>   	int bl_idx;
>   
> +	struct cec_notifier *notifier;
> +
>   	/* we need to mind the EDID between detect
>   	   and get modes due to analog/digital/tvencoder */
>   	const struct drm_edid *drm_edid;
> @@ -1010,4 +1012,8 @@ void dm_free_gpu_mem(struct amdgpu_device *adev,
>   
>   bool amdgpu_dm_is_headless(struct amdgpu_device *adev);
>   
> +void hdmi_cec_set_edid(struct amdgpu_dm_connector *aconnector);
> +void hdmi_cec_unset_edid(struct amdgpu_dm_connector *aconnector);
> +int amdgpu_dm_initialize_hdmi_connector(struct amdgpu_dm_connector *aconnector);
> +
>   #endif /* __AMDGPU_DM_H__ */
> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c
> index 0d84308c5..d189dddb1 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c
> @@ -25,6 +25,7 @@
>   
>   #include <linux/string_helpers.h>
>   #include <linux/uaccess.h>
> +#include <media/cec-notifier.h>
>   
>   #include "dc.h"
>   #include "amdgpu.h"
> @@ -2848,6 +2849,67 @@ static int is_dpia_link_show(struct seq_file *m, void *data)
>   	return 0;
>   }
>   
> +/**
> + * hdmi_cec_state_show - Read out the HDMI-CEC feature status
> + * @m: sequence file.
> + * @data: unused.
> + *
> + * Return 0 on success
> + */
> +static int hdmi_cec_state_show(struct seq_file *m, void *data)
> +{
> +	struct drm_connector *connector = m->private;
> +	struct amdgpu_dm_connector *aconnector = to_amdgpu_dm_connector(connector);
> +
> +	seq_printf(m, "%s:%d\n", connector->name, connector->base.id);
> +	seq_printf(m, "HDMI-CEC status: %d\n", aconnector->notifier ? 1 : 0);
> +
> +	return 0;
> +}
> +
> +/**
> + * hdmi_cec_state_write - Enable/Disable HDMI-CEC feature from driver side
> + * @f: file structure.
> + * @buf: userspace buffer. set to '1' to enable; '0' to disable cec feature.
> + * @size: size of buffer from userpsace.
> + * @pos: unused.
> + *
> + * Return size on success, error code on failure
> + */
> +static ssize_t hdmi_cec_state_write(struct file *f, const char __user *buf,
> +				     size_t size, loff_t *pos)
> +{
> +	int ret;
> +	bool enable;
> +	struct amdgpu_dm_connector *aconnector = file_inode(f)->i_private;
> +	struct drm_device *ddev = aconnector->base.dev;
> +
> +	if (size == 0)
> +		return -EINVAL;
> +
> +	ret = kstrtobool_from_user(buf, size, &enable);
> +	if (ret) {
> +		drm_dbg_driver(ddev, "invalid user data !\n");
> +		return ret;
> +	}
> +
> +	if (enable) {
> +		if (aconnector->notifier)
> +			return -EINVAL;
> +		ret = amdgpu_dm_initialize_hdmi_connector(aconnector);
> +		if (ret)
> +			return ret;
> +		hdmi_cec_set_edid(aconnector);
> +	} else {
> +		if (!aconnector->notifier)
> +			return -EINVAL;
> +		cec_notifier_conn_unregister(aconnector->notifier);
> +		aconnector->notifier = NULL;
> +	}
> +
> +	return size;
> +}
> +
>   DEFINE_SHOW_ATTRIBUTE(dp_dsc_fec_support);
>   DEFINE_SHOW_ATTRIBUTE(dmub_fw_state);
>   DEFINE_SHOW_ATTRIBUTE(dmub_tracebuffer);
> @@ -2860,6 +2922,7 @@ DEFINE_SHOW_ATTRIBUTE(psr_capability);
>   DEFINE_SHOW_ATTRIBUTE(dp_is_mst_connector);
>   DEFINE_SHOW_ATTRIBUTE(dp_mst_progress_status);
>   DEFINE_SHOW_ATTRIBUTE(is_dpia_link);
> +DEFINE_SHOW_STORE_ATTRIBUTE(hdmi_cec_state);
>   
>   static const struct file_operations dp_dsc_clock_en_debugfs_fops = {
>   	.owner = THIS_MODULE,
> @@ -2995,7 +3058,8 @@ static const struct {
>   	char *name;
>   	const struct file_operations *fops;
>   } hdmi_debugfs_entries[] = {
> -		{"hdcp_sink_capability", &hdcp_sink_capability_fops}
> +		{"hdcp_sink_capability", &hdcp_sink_capability_fops},
> +		{"hdmi_cec_state", &hdmi_cec_state_fops}
>   };
>   
>   /*
> diff --git a/drivers/gpu/drm/amd/include/amd_shared.h b/drivers/gpu/drm/amd/include/amd_shared.h
> index 98d9e840b..05bdb4e02 100644
> --- a/drivers/gpu/drm/amd/include/amd_shared.h
> +++ b/drivers/gpu/drm/amd/include/amd_shared.h
> @@ -344,6 +344,11 @@ enum DC_DEBUG_MASK {
>   	 * eDP display from ACPI _DDC method.
>   	 */
>   	DC_DISABLE_ACPI_EDID = 0x8000,
> +
> +	/*
> +	 * @DC_DISABLE_HDMI_CEC: If set, disable HDMI-CEC feature in amdgpu driver.
> +	 */
> +	DC_DISABLE_HDMI_CEC = 0x10000,
>   };
>   
>   enum amd_dpm_forced_level;



More information about the amd-gfx mailing list