W dniu 15.09.2020 o 20:02, Michael Tretter pisze:
> On Tue, 15 Sep 2020 19:07:59 +0200, Andrzej Hajda wrote:
>> W dniu 11.09.2020 o 15:54, Michael Tretter pisze:
>>> Platform drivers need to be aware if a mipi dsi device attaches or
>>> detaches. Add host_ops to the driver_data for attach and detach
>>> callbacks and move the i80 mode selection and the hotplug handling into
>>> the callback, because these depend on the drm driver.
>>>
>>> Signed-off-by: Michael Tretter <m.tretter@xxxxxxxxxxxxxx>
>>> ---
>>> v2:
>>> - new patch
>>> ---
>>> drivers/gpu/drm/exynos/exynos_drm_dsi.c | 64 ++++++++++++++++++++-----
>>> 1 file changed, 53 insertions(+), 11 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/exynos/exynos_drm_dsi.c b/drivers/gpu/drm/exynos/exynos_drm_dsi.c
>>> index 1a15ae71205d..684a2fbef08a 100644
>>> --- a/drivers/gpu/drm/exynos/exynos_drm_dsi.c
>>> +++ b/drivers/gpu/drm/exynos/exynos_drm_dsi.c
>>> @@ -239,6 +239,12 @@ struct exynos_dsi_transfer {
>>> #define DSIM_STATE_CMD_LPM BIT(2)
>>> #define DSIM_STATE_VIDOUT_AVAILABLE BIT(3)
>>>
>>> +struct exynos_dsi;
>>> +struct exynos_dsi_host_ops {
>>> + int (*attach)(struct device *dev, struct mipi_dsi_device *device);
>>> + int (*detach)(struct device *dev, struct mipi_dsi_device *device);
>>> +};
>>> +
>>> enum exynos_reg_offset {
>>> EXYNOS_REG_OFS,
>>> EXYNOS5433_REG_OFS
>>> @@ -254,6 +260,7 @@ struct exynos_dsi_driver_data {
>>> unsigned int wait_for_reset;
>>> unsigned int num_bits_resol;
>>> const unsigned int *reg_values;
>>> + const struct exynos_dsi_host_ops *host_ops;
>>> };
>>>
>>> struct exynos_dsi {
>>> @@ -467,6 +474,41 @@ static const unsigned int exynos5433_reg_values[] = {
>>> [PHYTIMING_HS_TRAIL] = 0x0c,
>>> };
>>>
>>> +static int __exynos_dsi_host_attach(struct device *dev,
>>> + struct mipi_dsi_device *device)
>>> +{
>>> + struct exynos_dsi *dsi = dev_get_drvdata(dev);
>>> + struct drm_device *drm = dsi->encoder.dev;
>>
>> As I wrote yesterday drm device was guaranteed to be present here only
>> if mipi dsi host registration was performed in component bind. In case
>> it is performed in probe it will be always NULL, and the code does not
>> make sense.
> Correct, but if the driver is used as a drm bridge, there won't be an encoder
> until bridge_attach. Mipi dsi devices defer their probe until the mipi dsi
> host is available. If I move the mipi dsi host registration into
> bridge_attach, the driver does not know if the next device is another bridge
> or a panel during bridge_attach, but the driver cannot successfully return
> from bridge_attach, because then the drm driver expects a connector.
Hmm, I am not sure why do you think driver expects connector on return
of briddge_attach.
>
> I guess that the encoder should be initialized before registering the mipi dsi
> host during probe instead of bind.
But you should have already drm dev on encoder init which in probe is
unavailable.
> The probe won't be rolled back on
> PROBE_DEFER during bind and the encoder will be available in host_attach.
> When splitting the driver into the exynos platform specific code and the more
> generic code, there won't be an encoder during host_attach in the generic
> code, but the host_ops callback could (and will) use the platform specific
> encoder, which is available before bridge_attach.
>
> Does this make sense to you?
Nope :) But maybe I am missing sth.
Generally I see two ways (which I have already described in different
e-mail, in different words):
A. Static - we wait for every part of display stack to be probed, then
create drm_dev - typical approach, but slow (deferred probe causes late
drm creation), and racy - only(?) component framework and DSI bus have
possibility to signal driver unbind, so we can react on it properly.
B. Dynamic - drm framework requires only crtcs and encoders to be
attached to drm on init, connectors, and hidden parts (drm_bridges,
drm_panels) can be created/destroyed and attached/detached at any time
(almost), so lets take advantage of it - create drm_dev ASAP and attach
other parts when they become available, the only issue is that there is
no generic way to be notified when given parts becomes available - in
interesting area only mipi devices have such notifications via attach
callbacks.
So either we convert exynos_dsi to A either we continue B approach. In
second case we should assure mipi_dsi host is created if drm_dev is
available.
Regards
Andrzej
>
> Michael
>
>>
>> Regards
>>
>> Andrzej
>>
>>
>>
>>> + struct exynos_drm_crtc *crtc;
>>> +
>>> + mutex_lock(&drm->mode_config.mutex);
>>> + crtc = exynos_drm_crtc_get_by_type(drm, EXYNOS_DISPLAY_TYPE_LCD);
>>> + crtc->i80_mode = !(device->mode_flags & MIPI_DSI_MODE_VIDEO);
>>> + mutex_unlock(&drm->mode_config.mutex);
>>> +
>>> + if (drm->mode_config.poll_enabled)
>>> + drm_kms_helper_hotplug_event(drm);
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static int __exynos_dsi_host_detach(struct device *dev,
>>> + struct mipi_dsi_device *device)
>>> +{
>>> + struct exynos_dsi *dsi = dev_get_drvdata(dev);
>>> + struct drm_device *drm = dsi->encoder.dev;
>>> +
>>> + if (drm->mode_config.poll_enabled)
>>> + drm_kms_helper_hotplug_event(drm);
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static const struct exynos_dsi_host_ops exynos_dsi_host_ops = {
>>> + .attach = __exynos_dsi_host_attach,
>>> + .detach = __exynos_dsi_host_detach,
>>> +};
>>> +
>>> static const struct exynos_dsi_driver_data exynos3_dsi_driver_data = {
>>> .reg_ofs = EXYNOS_REG_OFS,
>>> .plltmr_reg = 0x50,
>>> @@ -477,6 +519,7 @@ static const struct exynos_dsi_driver_data exynos3_dsi_driver_data = {
>>> .wait_for_reset = 1,
>>> .num_bits_resol = 11,
>>> .reg_values = reg_values,
>>> + .host_ops = &exynos_dsi_host_ops,
>>> };
>>>
>>> static const struct exynos_dsi_driver_data exynos4_dsi_driver_data = {
>>> @@ -489,6 +532,7 @@ static const struct exynos_dsi_driver_data exynos4_dsi_driver_data = {
>>> .wait_for_reset = 1,
>>> .num_bits_resol = 11,
>>> .reg_values = reg_values,
>>> + .host_ops = &exynos_dsi_host_ops,
>>> };
>>>
>>> static const struct exynos_dsi_driver_data exynos5_dsi_driver_data = {
>>> @@ -499,6 +543,7 @@ static const struct exynos_dsi_driver_data exynos5_dsi_driver_data = {
>>> .wait_for_reset = 1,
>>> .num_bits_resol = 11,
>>> .reg_values = reg_values,
>>> + .host_ops = &exynos_dsi_host_ops,
>>> };
>>>
>>> static const struct exynos_dsi_driver_data exynos5433_dsi_driver_data = {
>>> @@ -510,6 +555,7 @@ static const struct exynos_dsi_driver_data exynos5433_dsi_driver_data = {
>>> .wait_for_reset = 0,
>>> .num_bits_resol = 12,
>>> .reg_values = exynos5433_reg_values,
>>> + .host_ops = &exynos_dsi_host_ops,
>>> };
>>>
>>> static const struct exynos_dsi_driver_data exynos5422_dsi_driver_data = {
>>> @@ -521,6 +567,7 @@ static const struct exynos_dsi_driver_data exynos5422_dsi_driver_data = {
>>> .wait_for_reset = 1,
>>> .num_bits_resol = 12,
>>> .reg_values = exynos5422_reg_values,
>>> + .host_ops = &exynos_dsi_host_ops,
>>> };
>>>
>>> static const struct of_device_id exynos_dsi_of_match[] = {
>>> @@ -1551,8 +1598,8 @@ static int exynos_dsi_host_attach(struct mipi_dsi_host *host,
>>> struct mipi_dsi_device *device)
>>> {
>>> struct exynos_dsi *dsi = host_to_dsi(host);
>>> + const struct exynos_dsi_host_ops *ops = dsi->driver_data->host_ops;
>>> struct drm_encoder *encoder = &dsi->encoder;
>>> - struct drm_device *drm = encoder->dev;
>>> struct drm_bridge *out_bridge;
>>>
>>> out_bridge = of_drm_find_bridge(device->dev.of_node);
>>> @@ -1590,18 +1637,12 @@ static int exynos_dsi_host_attach(struct mipi_dsi_host *host,
>>> return ret;
>>> }
>>>
>>> - mutex_lock(&drm->mode_config.mutex);
>>> -
>>> dsi->lanes = device->lanes;
>>> dsi->format = device->format;
>>> dsi->mode_flags = device->mode_flags;
>>> - exynos_drm_crtc_get_by_type(drm, EXYNOS_DISPLAY_TYPE_LCD)->i80_mode =
>>> - !(dsi->mode_flags & MIPI_DSI_MODE_VIDEO);
>>>
>>> - mutex_unlock(&drm->mode_config.mutex);
>>> -
>>> - if (drm->mode_config.poll_enabled)
>>> - drm_kms_helper_hotplug_event(drm);
>>> + if (ops && ops->attach)
>>> + ops->attach(dsi->dsi_host.dev, device);
>>>
>>> return 0;
>>> }
>>> @@ -1610,6 +1651,7 @@ static int exynos_dsi_host_detach(struct mipi_dsi_host *host,
>>> struct mipi_dsi_device *device)
>>> {
>>> struct exynos_dsi *dsi = host_to_dsi(host);
>>> + const struct exynos_dsi_host_ops *ops = dsi->driver_data->host_ops;
>>> struct drm_device *drm = dsi->encoder.dev;
>>>
>>> if (dsi->panel) {
>>> @@ -1625,8 +1667,8 @@ static int exynos_dsi_host_detach(struct mipi_dsi_host *host,
>>> INIT_LIST_HEAD(&dsi->bridge_chain);
>>> }
>>>
>>> - if (drm->mode_config.poll_enabled)
>>> - drm_kms_helper_hotplug_event(drm);
>>> + if (ops && ops->detach)
>>> + ops->detach(dsi->dsi_host.dev, device);
>>>
>>> exynos_dsi_unregister_te_irq(dsi);
>>>
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