Hi,
On 03-10-2024 15:13, Aradhya Bhatia wrote:
> Hi Wadim,
>
> Thanks for the patch.
>
> Probably a nit, but the dt-binding patch should come before the driver
> patch.
>
> On 03-10-2024 13:50, Wadim Egorov wrote:
>> Introduce a data-lines property to define the number of parallel RGB
>> input pins connected to the transmitter. The input bus formats are updated
>> accordingly. If the property is not specified, default to 24 data lines.
One more thing. This driver also supports the older way of
encoder-bridge connections - that is, with no
DRM_BRIDGE_ATTACH_NO_CONNECTOR flag.
In the sii902x_bridge_attach, you will see that the bus_format is being
statically assigned to MEDIA_BUS_FMT_RGB888_1X24. When the
ATTACH_NO_CONNECTOR flag is set, it doesn't matter. But when it is not,
the RGB888 bus format will get trickled back to the encoder even if the
dt property says differently.
>>
>> Signed-off-by: Wadim Egorov <w.ego...@phytec.de>
>> ---
>> drivers/gpu/drm/bridge/sii902x.c | 27 ++++++++++++++++++++++++++-
>> 1 file changed, 26 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/bridge/sii902x.c
>> b/drivers/gpu/drm/bridge/sii902x.c
>> index 7f91b0db161e..3565c3533597 100644
>> --- a/drivers/gpu/drm/bridge/sii902x.c
>> +++ b/drivers/gpu/drm/bridge/sii902x.c
>> @@ -180,6 +180,8 @@ struct sii902x {
>> struct gpio_desc *reset_gpio;
>> struct i2c_mux_core *i2cmux;
>> bool sink_is_hdmi;
>> + u32 pd_lines; /* number of Parallel Port Input Data Lines */
>> +
>> /*
>> * Mutex protects audio and video functions from interfering
>> * each other, by keeping their i2c command sequences atomic.
>> @@ -477,6 +479,8 @@ static u32
>> *sii902x_bridge_atomic_get_input_bus_fmts(struct drm_bridge *bridge,
>> u32 output_fmt,
>> unsigned int
>> *num_input_fmts)
>> {
>> +
And this is probably a stray.
>> + struct sii902x *sii902x = bridge_to_sii902x(bridge);
>> u32 *input_fmts;
>>
>> *num_input_fmts = 0;
>> @@ -485,7 +489,19 @@ static u32
>> *sii902x_bridge_atomic_get_input_bus_fmts(struct drm_bridge *bridge,
>> if (!input_fmts)
>> return NULL;
>>
>> - input_fmts[0] = MEDIA_BUS_FMT_RGB888_1X24;
>> + switch (sii902x->pd_lines) {
>> + case 16:
>> + input_fmts[0] = MEDIA_BUS_FMT_RGB565_1X16;
>> + break;
>> + case 18:
>> + input_fmts[0] = MEDIA_BUS_FMT_RGB666_1X18;
>> + break;
>> + default:
>
> For backward compatibility - in cases where the property is absent - you
> have already defaulted sii902x->pd_lines to 24 below, which I think is
> the right way.
>
> So, the default case should be kept separately, as an error case -
> which should then return back NULL / num_input_fmts = 0.
>
>> + case 24:
>> + input_fmts[0] = MEDIA_BUS_FMT_RGB888_1X24;
>> + break;
>> + }
>> +
>> *num_input_fmts = 1;
>>
>> return input_fmts;
>> @@ -1167,6 +1183,15 @@ static int sii902x_probe(struct i2c_client *client)
>> return PTR_ERR(sii902x->reset_gpio);
>> }
>>
>> + endpoint = of_graph_get_endpoint_by_regs(dev->of_node, 0, -1);
>> + if (endpoint) {
>> + ret = of_property_read_u32(endpoint, "data-lines",
>> &sii902x->pd_lines);
>> + if (ret) {
>> + dev_dbg(dev, "Could not get data-lines, fallback to 24
>> data-lines\n");
>> + sii902x->pd_lines = 24;
>> + }
>> + }
>> +
>> endpoint = of_graph_get_endpoint_by_regs(dev->of_node, 1, -1);
>> if (endpoint) {
>> struct device_node *remote =
>> of_graph_get_remote_port_parent(endpoint);
>
> --
> Regards
> Aradhya
>
--
Regards
Aradhya
