[Freedreno] [PATCH v10 1/4] drm/msm/dp: Add eDP support via aux_bus
Dmitry Baryshkov
dmitry.baryshkov at linaro.org
Fri May 6 21:17:54 UTC 2022
On 07/05/2022 00:17, Abhinav Kumar wrote:
>
>
> On 5/6/2022 2:05 PM, Dmitry Baryshkov wrote:
>> On 07/05/2022 00:03, Abhinav Kumar wrote:
>>>
>>>
>>> On 5/6/2022 1:49 PM, Dmitry Baryshkov wrote:
>>>> On 25/04/2022 14:44, Sankeerth Billakanti wrote:
>>>>> This patch adds support for generic eDP sink through aux_bus. The
>>>>> eDP/DP
>>>>> controller driver should support aux transactions originating from the
>>>>> panel-edp driver and hence should be initialized and ready.
>>>>>
>>>>> The panel bridge supporting the panel should be ready before the
>>>>> bridge
>>>>> connector is initialized. The generic panel probe needs the controller
>>>>> resources to be enabled to support the aux transactions originating
>>>>> from
>>>>> the panel probe.
>>>>>
>>>>> Signed-off-by: Sankeerth Billakanti <quic_sbillaka at quicinc.com>
>>>>> Reviewed-by: Douglas Anderson <dianders at chromium.org>
>>>>> Reviewed-by: Stephen Boyd <swboyd at chromium.org>
>>>>
>>>> An additional side effect from this patch. Previously missing panel
>>>> would have caused the bind error. Now it is the dp_modeset_init
>>>> error, which translates to kms_hw_init returning -517. I kind ask to
>>>> move the next_bridge acquisition back to the dp_bind in one of the
>>>> followup patches.
>>>>
>>>
>>> This is true. But the end result would be same isnt it?
>>>
>>> When dp_display_bind() failed earlier, it would cause master bind
>>> failure too due to component model.
>>>
>>> Even now, it causes the same result?
>>
>> Yes, it helped us to uncover several error. But I'd still prefer to
>> have EPROBE_DEFER being returned earlier rather than later.
>
> Alright, point noted to try moving this earlier.
>
> We will be following this up with rounds of cleanups to implement the
> suggestions given by you and Doug earlier.
>
> This point shall be noted too.
Thanks a lot.
>
>>
>>>
>>>>> ---
>>>>> Changes in v10:
>>>>> - modify the error handling condition
>>>>> - modify the kernel doc
>>>>>
>>>>> Changes in v9:
>>>>> - add comments for panel probe
>>>>> - modify the error handling checks
>>>>>
>>>>> Changes in v8:
>>>>> - handle corner cases
>>>>> - add comment for the bridge ops
>>>>>
>>>>> Changes in v7:
>>>>> - aux_bus is mandatory for eDP
>>>>> - connector type check modified to just check for eDP
>>>>>
>>>>> Changes in v6:
>>>>> - Remove initialization
>>>>> - Fix aux_bus node leak
>>>>> - Split the patches
>>>>>
>>>>> drivers/gpu/drm/msm/dp/dp_display.c | 72
>>>>> ++++++++++++++++++++++++++++++++++---
>>>>> drivers/gpu/drm/msm/dp/dp_display.h | 1 +
>>>>> drivers/gpu/drm/msm/dp/dp_drm.c | 21 ++++++++---
>>>>> drivers/gpu/drm/msm/dp/dp_parser.c | 23 ++----------
>>>>> drivers/gpu/drm/msm/dp/dp_parser.h | 14 +++++++-
>>>>> 5 files changed, 101 insertions(+), 30 deletions(-)
>>>>>
>>>>> diff --git a/drivers/gpu/drm/msm/dp/dp_display.c
>>>>> b/drivers/gpu/drm/msm/dp/dp_display.c
>>>>> index d7a19d6..f772d84 100644
>>>>> --- a/drivers/gpu/drm/msm/dp/dp_display.c
>>>>> +++ b/drivers/gpu/drm/msm/dp/dp_display.c
>>>>> @@ -10,6 +10,7 @@
>>>>> #include <linux/component.h>
>>>>> #include <linux/of_irq.h>
>>>>> #include <linux/delay.h>
>>>>> +#include <drm/dp/drm_dp_aux_bus.h>
>>>>> #include "msm_drv.h"
>>>>> #include "msm_kms.h"
>>>>> @@ -259,14 +260,12 @@ static int dp_display_bind(struct device
>>>>> *dev, struct device *master,
>>>>> dp->dp_display.drm_dev = drm;
>>>>> priv->dp[dp->id] = &dp->dp_display;
>>>>> - rc = dp->parser->parse(dp->parser,
>>>>> dp->dp_display.connector_type);
>>>>> + rc = dp->parser->parse(dp->parser);
>>>>> if (rc) {
>>>>> DRM_ERROR("device tree parsing failed\n");
>>>>> goto end;
>>>>> }
>>>>> - dp->dp_display.next_bridge = dp->parser->next_bridge;
>>>>> -
>>>>> dp->aux->drm_dev = drm;
>>>>> rc = dp_aux_register(dp->aux);
>>>>> if (rc) {
>>>>> @@ -1319,6 +1318,8 @@ static int dp_display_probe(struct
>>>>> platform_device *pdev)
>>>>> dp->pdev = pdev;
>>>>> dp->name = "drm_dp";
>>>>> dp->dp_display.connector_type = desc->connector_type;
>>>>> + dp->dp_display.is_edp =
>>>>> + (dp->dp_display.connector_type == DRM_MODE_CONNECTOR_eDP);
>>>>> rc = dp_init_sub_modules(dp);
>>>>> if (rc) {
>>>>> @@ -1508,7 +1509,8 @@ void msm_dp_irq_postinstall(struct msm_dp
>>>>> *dp_display)
>>>>> dp_hpd_event_setup(dp);
>>>>> - dp_add_event(dp, EV_HPD_INIT_SETUP, 0, 100);
>>>>> + if (!dp_display->is_edp)
>>>>> + dp_add_event(dp, EV_HPD_INIT_SETUP, 0, 100);
>>>>> }
>>>>> void msm_dp_debugfs_init(struct msm_dp *dp_display, struct
>>>>> drm_minor *minor)
>>>>> @@ -1530,6 +1532,64 @@ void msm_dp_debugfs_init(struct msm_dp
>>>>> *dp_display, struct drm_minor *minor)
>>>>> }
>>>>> }
>>>>> +static int dp_display_get_next_bridge(struct msm_dp *dp)
>>>>> +{
>>>>> + int rc;
>>>>> + struct dp_display_private *dp_priv;
>>>>> + struct device_node *aux_bus;
>>>>> + struct device *dev;
>>>>> +
>>>>> + dp_priv = container_of(dp, struct dp_display_private,
>>>>> dp_display);
>>>>> + dev = &dp_priv->pdev->dev;
>>>>> + aux_bus = of_get_child_by_name(dev->of_node, "aux-bus");
>>>>> +
>>>>> + if (aux_bus && dp->is_edp) {
>>>>> + dp_display_host_init(dp_priv);
>>>>> + dp_catalog_ctrl_hpd_config(dp_priv->catalog);
>>>>> + dp_display_host_phy_init(dp_priv);
>>>>> + enable_irq(dp_priv->irq);
>>>>> +
>>>>> + /*
>>>>> + * The code below assumes that the panel will finish probing
>>>>> + * by the time devm_of_dp_aux_populate_ep_devices() returns.
>>>>> + * This isn't a great assumption since it will fail if the
>>>>> + * panel driver is probed asynchronously but is the best we
>>>>> + * can do without a bigger driver reorganization.
>>>>> + */
>>>>> + rc = devm_of_dp_aux_populate_ep_devices(dp_priv->aux);
>>>>> + of_node_put(aux_bus);
>>>>> + if (rc)
>>>>> + goto error;
>>>>> + } else if (dp->is_edp) {
>>>>> + DRM_ERROR("eDP aux_bus not found\n");
>>>>> + return -ENODEV;
>>>>> + }
>>>>> +
>>>>> + /*
>>>>> + * External bridges are mandatory for eDP interfaces: one has to
>>>>> + * provide at least an eDP panel (which gets wrapped into
>>>>> panel-bridge).
>>>>> + *
>>>>> + * For DisplayPort interfaces external bridges are optional, so
>>>>> + * silently ignore an error if one is not present (-ENODEV).
>>>>> + */
>>>>> + rc = dp_parser_find_next_bridge(dp_priv->parser);
>>>>> + if (!dp->is_edp && rc == -ENODEV)
>>>>> + return 0;
>>>>> +
>>>>> + if (!rc) {
>>>>> + dp->next_bridge = dp_priv->parser->next_bridge;
>>>>> + return 0;
>>>>> + }
>>>>> +
>>>>> +error:
>>>>> + if (dp->is_edp) {
>>>>> + disable_irq(dp_priv->irq);
>>>>> + dp_display_host_phy_exit(dp_priv);
>>>>> + dp_display_host_deinit(dp_priv);
>>>>> + }
>>>>> + return rc;
>>>>> +}
>>>>> +
>>>>> int msm_dp_modeset_init(struct msm_dp *dp_display, struct
>>>>> drm_device *dev,
>>>>> struct drm_encoder *encoder)
>>>>> {
>>>>> @@ -1553,6 +1613,10 @@ int msm_dp_modeset_init(struct msm_dp
>>>>> *dp_display, struct drm_device *dev,
>>>>> dp_display->encoder = encoder;
>>>>> + ret = dp_display_get_next_bridge(dp_display);
>>>>> + if (ret)
>>>>> + return ret;
>>>>> +
>>>>> dp_display->bridge = dp_bridge_init(dp_display, dev, encoder);
>>>>> if (IS_ERR(dp_display->bridge)) {
>>>>> ret = PTR_ERR(dp_display->bridge);
>>>>> diff --git a/drivers/gpu/drm/msm/dp/dp_display.h
>>>>> b/drivers/gpu/drm/msm/dp/dp_display.h
>>>>> index 49a1d89..1377cc3 100644
>>>>> --- a/drivers/gpu/drm/msm/dp/dp_display.h
>>>>> +++ b/drivers/gpu/drm/msm/dp/dp_display.h
>>>>> @@ -21,6 +21,7 @@ struct msm_dp {
>>>>> bool audio_enabled;
>>>>> bool power_on;
>>>>> unsigned int connector_type;
>>>>> + bool is_edp;
>>>>> hdmi_codec_plugged_cb plugged_cb;
>>>>> diff --git a/drivers/gpu/drm/msm/dp/dp_drm.c
>>>>> b/drivers/gpu/drm/msm/dp/dp_drm.c
>>>>> index 7ce1aca..8a75c55 100644
>>>>> --- a/drivers/gpu/drm/msm/dp/dp_drm.c
>>>>> +++ b/drivers/gpu/drm/msm/dp/dp_drm.c
>>>>> @@ -114,10 +114,23 @@ struct drm_bridge *dp_bridge_init(struct
>>>>> msm_dp *dp_display, struct drm_device *
>>>>> bridge->funcs = &dp_bridge_ops;
>>>>> bridge->type = dp_display->connector_type;
>>>>> - bridge->ops =
>>>>> - DRM_BRIDGE_OP_DETECT |
>>>>> - DRM_BRIDGE_OP_HPD |
>>>>> - DRM_BRIDGE_OP_MODES;
>>>>> + /*
>>>>> + * Many ops only make sense for DP. Why?
>>>>> + * - Detect/HPD are used by DRM to know if a display is
>>>>> _physically_
>>>>> + * there, not whether the display is powered on / finished
>>>>> initting.
>>>>> + * On eDP we assume the display is always there because you
>>>>> can't
>>>>> + * know until power is applied. If we don't implement the
>>>>> ops DRM will
>>>>> + * assume our display is always there.
>>>>> + * - Currently eDP mode reading is driven by the panel driver.
>>>>> This
>>>>> + * allows the panel driver to properly power itself on to
>>>>> read the
>>>>> + * modes.
>>>>> + */
>>>>> + if (!dp_display->is_edp) {
>>>>> + bridge->ops =
>>>>> + DRM_BRIDGE_OP_DETECT |
>>>>> + DRM_BRIDGE_OP_HPD |
>>>>> + DRM_BRIDGE_OP_MODES;
>>>>> + }
>>>>> rc = drm_bridge_attach(encoder, bridge, NULL,
>>>>> DRM_BRIDGE_ATTACH_NO_CONNECTOR);
>>>>> if (rc) {
>>>>> diff --git a/drivers/gpu/drm/msm/dp/dp_parser.c
>>>>> b/drivers/gpu/drm/msm/dp/dp_parser.c
>>>>> index 1056b8d..4bdbf91 100644
>>>>> --- a/drivers/gpu/drm/msm/dp/dp_parser.c
>>>>> +++ b/drivers/gpu/drm/msm/dp/dp_parser.c
>>>>> @@ -265,7 +265,7 @@ static int dp_parser_clock(struct dp_parser
>>>>> *parser)
>>>>> return 0;
>>>>> }
>>>>> -static int dp_parser_find_next_bridge(struct dp_parser *parser)
>>>>> +int dp_parser_find_next_bridge(struct dp_parser *parser)
>>>>> {
>>>>> struct device *dev = &parser->pdev->dev;
>>>>> struct drm_bridge *bridge;
>>>>> @@ -279,7 +279,7 @@ static int dp_parser_find_next_bridge(struct
>>>>> dp_parser *parser)
>>>>> return 0;
>>>>> }
>>>>> -static int dp_parser_parse(struct dp_parser *parser, int
>>>>> connector_type)
>>>>> +static int dp_parser_parse(struct dp_parser *parser)
>>>>> {
>>>>> int rc = 0;
>>>>> @@ -300,25 +300,6 @@ static int dp_parser_parse(struct dp_parser
>>>>> *parser, int connector_type)
>>>>> if (rc)
>>>>> return rc;
>>>>> - /*
>>>>> - * External bridges are mandatory for eDP interfaces: one has to
>>>>> - * provide at least an eDP panel (which gets wrapped into
>>>>> panel-bridge).
>>>>> - *
>>>>> - * For DisplayPort interfaces external bridges are optional, so
>>>>> - * silently ignore an error if one is not present (-ENODEV).
>>>>> - */
>>>>> - rc = dp_parser_find_next_bridge(parser);
>>>>> - if (rc == -ENODEV) {
>>>>> - if (connector_type == DRM_MODE_CONNECTOR_eDP) {
>>>>> - DRM_ERROR("eDP: next bridge is not present\n");
>>>>> - return rc;
>>>>> - }
>>>>> - } else if (rc) {
>>>>> - if (rc != -EPROBE_DEFER)
>>>>> - DRM_ERROR("DP: error parsing next bridge: %d\n", rc);
>>>>> - return rc;
>>>>> - }
>>>>> -
>>>>> /* Map the corresponding regulator information according to
>>>>> * version. Currently, since we only have one supported
>>>>> platform,
>>>>> * mapping the regulator directly.
>>>>> diff --git a/drivers/gpu/drm/msm/dp/dp_parser.h
>>>>> b/drivers/gpu/drm/msm/dp/dp_parser.h
>>>>> index d371bae..3a4d797 100644
>>>>> --- a/drivers/gpu/drm/msm/dp/dp_parser.h
>>>>> +++ b/drivers/gpu/drm/msm/dp/dp_parser.h
>>>>> @@ -125,7 +125,7 @@ struct dp_parser {
>>>>> u32 max_dp_lanes;
>>>>> struct drm_bridge *next_bridge;
>>>>> - int (*parse)(struct dp_parser *parser, int connector_type);
>>>>> + int (*parse)(struct dp_parser *parser);
>>>>> };
>>>>> /**
>>>>> @@ -141,4 +141,16 @@ struct dp_parser {
>>>>> */
>>>>> struct dp_parser *dp_parser_get(struct platform_device *pdev);
>>>>> +/**
>>>>> + * dp_parser_find_next_bridge() - find an additional bridge to DP
>>>>> + *
>>>>> + * @parser: dp_parser data from client
>>>>> + *
>>>>> + * This function is used to find any additional bridge attached to
>>>>> + * the DP controller. The eDP interface requires a panel bridge.
>>>>> + *
>>>>> + * Return: 0 if able to get the bridge, otherwise negative errno
>>>>> for failure.
>>>>> + */
>>>>> +int dp_parser_find_next_bridge(struct dp_parser *parser);
>>>>> +
>>>>> #endif
>>>>
>>>>
>>
>>
--
With best wishes
Dmitry
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