Re: [RESEND PATCH v5 3/3] drm/atmel-hlcdc: support bus-width (12/16/18/24) in endpoint nodes

From: Peter Rosin
Date: Fri Aug 03 2018 - 04:26:40 EST


On 2018-08-03 10:17, jacopo mondi wrote:
> Hi Peter,
>
> On Fri, Aug 03, 2018 at 09:23:08AM +0200, Peter Rosin wrote:
>> This beats the heuristic that the connector is involved in what format
>> should be output for cases where this fails.
>>
>> E.g. if there is a bridge that changes format between the encoder and the
>> connector, or if some of the RGB pins between the lcd controller and the
>> encoder are not routed on the PCB.
>>
>> This is critical for the devices that have the "conflicting output
>> formats" issue (SAM9N12, SAM9X5, SAMA5D3), since the most significant
>> RGB bits move around depending on the selected output mode. For
>> devices that do not have the "conflicting output formats" issue
>> (SAMA5D2, SAMA5D4), this is completely irrelevant.
>>
>> Acked-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxx>
>> Signed-off-by: Peter Rosin <peda@xxxxxxxxxx>
>> ---
>> drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c | 70 +++++++++++++++++-------
>> drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.h | 1 +
>> drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_output.c | 67 ++++++++++++++++++++---
>> 3 files changed, 111 insertions(+), 27 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c
>> index d73281095fac..c38a479ada98 100644
>> --- a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c
>> +++ b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c
>> @@ -226,6 +226,55 @@ static void atmel_hlcdc_crtc_atomic_enable(struct drm_crtc *c,
>> #define ATMEL_HLCDC_RGB888_OUTPUT BIT(3)
>> #define ATMEL_HLCDC_OUTPUT_MODE_MASK GENMASK(3, 0)
>>
>> +static int atmel_hlcdc_connector_output_mode(struct drm_connector_state *state)
>> +{
>> + struct drm_connector *connector = state->connector;
>> + struct drm_display_info *info = &connector->display_info;
>> + struct drm_encoder *encoder;
>> + unsigned int supported_fmts = 0;
>> + int j;
>> +
>> + encoder = state->best_encoder;
>> + if (!encoder)
>> + encoder = connector->encoder;
>> +
>> + switch (atmel_hlcdc_encoder_get_bus_fmt(encoder)) {
>> + case 0:
>> + break;
>> + case MEDIA_BUS_FMT_RGB444_1X12:
>> + return ATMEL_HLCDC_RGB444_OUTPUT;
>> + case MEDIA_BUS_FMT_RGB565_1X16:
>> + return ATMEL_HLCDC_RGB565_OUTPUT;
>> + case MEDIA_BUS_FMT_RGB666_1X18:
>> + return ATMEL_HLCDC_RGB666_OUTPUT;
>> + case MEDIA_BUS_FMT_RGB888_1X24:
>> + return ATMEL_HLCDC_RGB888_OUTPUT;
>> + default:
>> + return -EINVAL;
>> + }
>> +
>> + for (j = 0; j < info->num_bus_formats; j++) {
>> + switch (info->bus_formats[j]) {
>> + case MEDIA_BUS_FMT_RGB444_1X12:
>> + supported_fmts |= ATMEL_HLCDC_RGB444_OUTPUT;
>> + break;
>> + case MEDIA_BUS_FMT_RGB565_1X16:
>> + supported_fmts |= ATMEL_HLCDC_RGB565_OUTPUT;
>> + break;
>> + case MEDIA_BUS_FMT_RGB666_1X18:
>> + supported_fmts |= ATMEL_HLCDC_RGB666_OUTPUT;
>> + break;
>> + case MEDIA_BUS_FMT_RGB888_1X24:
>> + supported_fmts |= ATMEL_HLCDC_RGB888_OUTPUT;
>> + break;
>> + default:
>> + break;
>> + }
>> + }
>> +
>> + return supported_fmts;
>> +}
>> +
>> static int atmel_hlcdc_crtc_select_output_mode(struct drm_crtc_state *state)
>> {
>> unsigned int output_fmts = ATMEL_HLCDC_OUTPUT_MODE_MASK;
>> @@ -238,31 +287,12 @@ static int atmel_hlcdc_crtc_select_output_mode(struct drm_crtc_state *state)
>> crtc = drm_crtc_to_atmel_hlcdc_crtc(state->crtc);
>>
>> for_each_new_connector_in_state(state->state, connector, cstate, i) {
>> - struct drm_display_info *info = &connector->display_info;
>> unsigned int supported_fmts = 0;
>> - int j;
>>
>> if (!cstate->crtc)
>> continue;
>>
>> - for (j = 0; j < info->num_bus_formats; j++) {
>> - switch (info->bus_formats[j]) {
>> - case MEDIA_BUS_FMT_RGB444_1X12:
>> - supported_fmts |= ATMEL_HLCDC_RGB444_OUTPUT;
>> - break;
>> - case MEDIA_BUS_FMT_RGB565_1X16:
>> - supported_fmts |= ATMEL_HLCDC_RGB565_OUTPUT;
>> - break;
>> - case MEDIA_BUS_FMT_RGB666_1X18:
>> - supported_fmts |= ATMEL_HLCDC_RGB666_OUTPUT;
>> - break;
>> - case MEDIA_BUS_FMT_RGB888_1X24:
>> - supported_fmts |= ATMEL_HLCDC_RGB888_OUTPUT;
>> - break;
>> - default:
>> - break;
>> - }
>> - }
>> + supported_fmts = atmel_hlcdc_connector_output_mode(cstate);
>>
>> if (crtc->dc->desc->conflicting_output_formats)
>> output_fmts &= supported_fmts;
>> diff --git a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.h b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.h
>> index 60c937f42114..4cc1e03f0aee 100644
>> --- a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.h
>> +++ b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.h
>> @@ -441,5 +441,6 @@ void atmel_hlcdc_crtc_irq(struct drm_crtc *c);
>> int atmel_hlcdc_crtc_create(struct drm_device *dev);
>>
>> int atmel_hlcdc_create_outputs(struct drm_device *dev);
>> +int atmel_hlcdc_encoder_get_bus_fmt(struct drm_encoder *encoder);
>>
>> #endif /* DRM_ATMEL_HLCDC_H */
>> diff --git a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_output.c b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_output.c
>> index 8db51fb131db..db4d6aaaef93 100644
>> --- a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_output.c
>> +++ b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_output.c
>> @@ -27,33 +27,86 @@
>>
>> #include "atmel_hlcdc_dc.h"
>>
>> +struct atmel_hlcdc_rgb_output {
>> + struct drm_encoder encoder;
>> + int bus_fmt;
>> +};
>> +
>> static const struct drm_encoder_funcs atmel_hlcdc_panel_encoder_funcs = {
>> .destroy = drm_encoder_cleanup,
>> };
>>
>> +static struct atmel_hlcdc_rgb_output *
>> +atmel_hlcdc_encoder_to_rgb_output(struct drm_encoder *encoder)
>> +{
>> + return container_of(encoder, struct atmel_hlcdc_rgb_output, encoder);
>> +}
>> +
>> +int atmel_hlcdc_encoder_get_bus_fmt(struct drm_encoder *encoder)
>
> 'static' missing?

No, it's also used from atmel_hlcdc_crtc.c

>> +{
>> + struct atmel_hlcdc_rgb_output *output;
>> +
>> + output = atmel_hlcdc_encoder_to_rgb_output(encoder);
>> +
>> + return output->bus_fmt;
>> +}
>> +
>> +static int atmel_hlcdc_of_bus_fmt(struct device_node *ep)
>> +{
>> + u32 bus_width = 0;
>> +
>> + of_property_read_u32(ep, "bus-width", &bus_width);
>> +
>> + switch (bus_width) {
>> + case 0:
>> + return 0;
>> + case 12:
>> + return MEDIA_BUS_FMT_RGB444_1X12;
>> + case 16:
>> + return MEDIA_BUS_FMT_RGB565_1X16;
>> + case 18:
>> + return MEDIA_BUS_FMT_RGB666_1X18;
>> + case 24:
>> + return MEDIA_BUS_FMT_RGB888_1X24;
>> + default:
>> + return -EINVAL;
>> + }
>> +}
>> +
>> static int atmel_hlcdc_attach_endpoint(struct drm_device *dev, int endpoint)
>> {
>> - struct drm_encoder *encoder;
>> + struct atmel_hlcdc_rgb_output *output;
>> + struct device_node *ep;
>> struct drm_panel *panel;
>> struct drm_bridge *bridge;
>> int ret;
>>
>> + ep = of_graph_get_endpoint_by_regs(dev->dev->of_node, 0, endpoint);
>> + if (!ep)
>> + return -ENODEV;
>> +
>> ret = drm_of_find_panel_or_bridge(dev->dev->of_node, 0, endpoint,
>> &panel, &bridge);
>> if (ret)
>> return ret;
>>
>> - encoder = devm_kzalloc(dev->dev, sizeof(*encoder), GFP_KERNEL);
>> - if (!encoder)
>> + output = devm_kzalloc(dev->dev, sizeof(*output), GFP_KERNEL);
>> + if (!output)
>> return -EINVAL;
>>
>> - ret = drm_encoder_init(dev, encoder,
>> + output->bus_fmt = atmel_hlcdc_of_bus_fmt(ep);
>> + if (output->bus_fmt < 0) {
>> + dev_err(dev->dev, "invalid bus width\n");
>
> Nit: Bindings do not specify 0 as an accepted value.

I'll add some error checks in atmel_hlcdc_of_bus_fmt...

Cheers,
Peter

> Feel free to add my
> Reviewed-by: Jacopo Mondi <jacopo+renesas@xxxxxxxxxx>
> with those two minors addressed.
>
> Thanks
> j
>> + return -EINVAL;
>> + }
>> +
>> + ret = drm_encoder_init(dev, &output->encoder,
>> &atmel_hlcdc_panel_encoder_funcs,
>> DRM_MODE_ENCODER_NONE, NULL);
>> if (ret)
>> return ret;
>>
>> - encoder->possible_crtcs = 0x1;
>> + output->encoder.possible_crtcs = 0x1;
>>
>> if (panel) {
>> bridge = drm_panel_bridge_add(panel, DRM_MODE_CONNECTOR_Unknown);
>> @@ -62,7 +115,7 @@ static int atmel_hlcdc_attach_endpoint(struct drm_device *dev, int endpoint)
>> }
>>
>> if (bridge) {
>> - ret = drm_bridge_attach(encoder, bridge, NULL);
>> + ret = drm_bridge_attach(&output->encoder, bridge, NULL);
>> if (!ret)
>> return 0;
>>
>> @@ -70,7 +123,7 @@ static int atmel_hlcdc_attach_endpoint(struct drm_device *dev, int endpoint)
>> drm_panel_bridge_remove(bridge);
>> }
>>
>> - drm_encoder_cleanup(encoder);
>> + drm_encoder_cleanup(&output->encoder);
>>
>> return ret;
>> }
>> --
>> 2.11.0
>>