[PATCH v3 11/50] drm/bridge: Add bridge driver for display connectors

[Tomi Valkeinen]

On 11/12/2019 00:57, Laurent Pinchart wrote:
> Display connectors are modelled in DT as a device node, but have so far
> been handled manually in several bridge drivers. This resulted in
> duplicate code in several bridge drivers, with slightly different (and
> thus confusing) logics.
> 
> In order to fix this, implement a bridge driver for display connectors.
> The driver centralises logic for the DVI, HDMI, VGAn composite and
> S-video connectors and exposes corresponding bridge operations.
> 
> This driver in itself doesn't solve the issue completely, changes in
> bridge and display controller drivers are needed to make use of the new
> connector driver.
> 
> Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> Reviewed-by: Maxime Ripard <mripard at kernel.org>
> ---
> Changes since v2:
> 
> - Fall back to polling if the GPIO IRQ chip doesn't support
>    edge-triggered interrupts
> 
> Changes since v1:
> 
> - Use drm_get_connector_type_name() instead of open-coding
>    display_connector_type_name()
> - Remove empty .hpd_enable() and .hpd_disable() operations
> - Set bridge.ddc
> ---
>   drivers/gpu/drm/bridge/Kconfig             |  11 +
>   drivers/gpu/drm/bridge/Makefile            |   1 +
>   drivers/gpu/drm/bridge/display-connector.c | 292 +++++++++++++++++++++
>   3 files changed, 304 insertions(+)
>   create mode 100644 drivers/gpu/drm/bridge/display-connector.c

<snip>

> +	dev_info(&pdev->dev,
> +		 "Found %s display connector '%s' %s DDC bus and %s HPD GPIO (ops 0x%x)\n",
> +		 drm_get_connector_type_name(conn->bridge.type),
> +		 conn->label ? conn->label : "<unlabelled>",
> +		 conn->bridge.ddc ? "with" : "without",
> +		 conn->hpd_gpio ? "with" : "without",
> +		 conn->bridge.ops);

On AM5 EVM, we have HDMI output with DDC and HPD, but I get a kernel print:

display-connector connector: Found HDMI-A display connector 'hdmi' without DDC bus and without HPD 
GPIO (ops 0x0)

I think that print may be quite confusing for someone who doesn't know the details of the drivers 
involved.

  Tomi

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