[PATCH] drm/amd/display: add CEC notifier to amdgpu driver
Mario Limonciello
mario.limonciello at amd.com
Mon Jan 6 03:03:34 UTC 2025
On 12/30/2024 02:15, 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>
> ---
> drivers/gpu/drm/amd/display/Kconfig | 2 +
> .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 82 +++++++++++++++++++
> .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h | 4 +
> .../amd/display/amdgpu_dm/amdgpu_dm_debugfs.c | 66 ++++++++++++++-
> drivers/gpu/drm/amd/include/amd_shared.h | 5 ++
> 5 files changed, 158 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/display/Kconfig b/drivers/gpu/drm/amd/display/Kconfig
> index 11e3f2f3b1..abd3b65643 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 85f21db6ef..3bd93cc14f 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"
> @@ -2746,6 +2747,54 @@ static void resume_mst_branch_status(struct drm_dp_mst_topology_mgr *mgr)
> mutex_unlock(&mgr->lock);
> }
>
> +static void hdmi_cec_unset_edid(struct amdgpu_dm_connector *aconnector)
> +{
> + struct drm_device *ddev = aconnector->base.dev;
> + struct cec_notifier *n = aconnector->notifier;
> +
> + if (!n) {
> + drm_dbg(ddev, "failed to unset edid\n");
> + return;
> + }
> +
> + cec_notifier_phys_addr_invalidate(n);
> +}
> +
> +static void hdmi_cec_set_edid(struct amdgpu_dm_connector *aconnector)
> +{
> + struct drm_connector *connector = &aconnector->base;
> + struct drm_device *ddev = aconnector->base.dev;
> + struct cec_notifier *n = aconnector->notifier;
> +
> + if (!n) {
> + drm_dbg(ddev, "failed to set edid\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;
> @@ -3017,6 +3066,8 @@ 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);
> @@ -3289,6 +3340,8 @@ 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);
>
> @@ -3598,6 +3651,7 @@ 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);
> }
> @@ -3607,6 +3661,7 @@ 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);
> @@ -3623,6 +3678,7 @@ 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;
> @@ -7042,6 +7098,7 @@ 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);
> }
>
> @@ -8278,6 +8335,27 @@ 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
> @@ -8341,6 +8419,10 @@ 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 6464a83783..4c1942652b 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 +1012,6 @@ void dm_free_gpu_mem(struct amdgpu_device *adev,
>
> bool amdgpu_dm_is_headless(struct amdgpu_device *adev);
>
> +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 6a97bb2d91..922f329175 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"
> @@ -2825,6 +2826,67 @@ static int is_dpia_link_show(struct seq_file *m, void *data)
> return 0;
> }
>
> +/*
I would make this kerneldoc (IE /**)
> + * function description: Read out the HDMI-CEC feature status
When converting it to kerneldoc format make sure you follow all the
other syntax.
IE
hdmi_cec_state_show: Read out the HDMI-CEC feature status
@m: sequence file
@data: unused
Returns: 0 on success, error on failure
> + *
> + * Example usage:
> + * cat /sys/kernel/debug/dri/0/HDMI-A-1/hdmi_cec_state
> + */
> +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;
> +}
> +
> +/*
I would make this kerneldoc (IE /**)
> + * function: Enable/Disable HDMI-CEC feature from driver side
> + *
When converting it to kerneldoc format make sure you follow all the
other syntax.
IE
hdmi_cec_state_write: Enable/Disable HDMI-CEC feature from driver side
@f: file
@buf: buffer from userspace
@size: size of buffer from userpsace
@pos: position in the buffer from userspace
Returns: size on success, error code on failure
> + * Example usage:
> + * echo 1 > /sys/kernel/debug/dri/0/HDMI-A-1/hdmi_cec_state
> + * echo 0 > /sys/kernel/debug/dri/0/HDMI-A-1/hdmi_cec_state
> + */
So by exposing this to debugfs you potentially introduce a case that a
user could call enable on an already enabled device or disable on an
already disabled device.
I think this is generally not something we want to allow. Perhaps could
you check for
'aconnector->notifier' being already set in the "1" case and already
being "NULL" in the "0" case and return -EINVAL?
> +static ssize_t hdmi_cec_state_write(struct file *f, const char __user *buf,
> + size_t size, loff_t *pos)
> +{
> + char tmp[2];
> + int ret;
> + struct amdgpu_dm_connector *aconnector = file_inode(f)->i_private;
> + struct drm_connector *dconn = &aconnector->base;
> + struct drm_device *ddev = aconnector->base.dev;
> +
> + if (size == 0)
> + return -EINVAL;
> +
> + if (copy_from_user(tmp, buf, 1)) {
> + drm_dbg_driver(ddev, "Failed to copy user data !\n");
> + return -EFAULT;
> + }
> +
> + switch (tmp[0]) {
What do you think about using kstrtobool() instead? Then you could
support a variety of inputs that people generally use for boolean stuff.
> + case '0':
> + cec_notifier_conn_unregister(aconnector->notifier);
> + aconnector->notifier = NULL;
> + break;
> + case '1':
> + ret = amdgpu_dm_initialize_hdmi_connector(aconnector);
> + if (ret)
> + return ret;
> + cec_notifier_set_phys_addr(aconnector->notifier,
> + dconn->display_info.source_physical_address);
> + break;
> + default:
> + drm_dbg_driver(ddev, "Unsupported param\n");
> + break;
Shouldn't you be returning an error code here for the default case?
> + }
> +
> + return size;
> +}
> +
> DEFINE_SHOW_ATTRIBUTE(dp_dsc_fec_support);
> DEFINE_SHOW_ATTRIBUTE(dmub_fw_state);
> DEFINE_SHOW_ATTRIBUTE(dmub_tracebuffer);
> @@ -2837,6 +2899,7 @@ 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,
> @@ -2972,7 +3035,8 @@ 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 98d9e840b0..05bdb4e020 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;
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