[PATCH 07/14] drm: bridge: icn6211: Add DSI lane count DT property parsing

[Marek Vasut]

On 2/3/22 13:13, Maxime Ripard wrote:
> On Fri, Jan 14, 2022 at 04:48:31AM +0100, Marek Vasut wrote:
>> The driver currently hard-codes DSI lane count to two, however the chip
>> is capable of operating in 1..4 DSI lanes mode. Parse 'data-lanes' DT
>> property and program the result into DSI_CTRL register.
>>
>> Signed-off-by: Marek Vasut <marex at denx.de>
>> Cc: Jagan Teki <jagan at amarulasolutions.com>
>> Cc: Robert Foss <robert.foss at linaro.org>
>> Cc: Sam Ravnborg <sam at ravnborg.org>
>> Cc: Thomas Zimmermann <tzimmermann at suse.de>
>> To: dri-devel at lists.freedesktop.org
>> ---
>>   drivers/gpu/drm/bridge/chipone-icn6211.c | 35 ++++++++++++++++++++----
>>   1 file changed, 29 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/bridge/chipone-icn6211.c b/drivers/gpu/drm/bridge/chipone-icn6211.c
>> index 3ad082c1d2bfd..400a566026ab4 100644
>> --- a/drivers/gpu/drm/bridge/chipone-icn6211.c
>> +++ b/drivers/gpu/drm/bridge/chipone-icn6211.c
>> @@ -135,10 +135,12 @@ struct chipone {
>>   	struct device *dev;
>>   	struct drm_bridge bridge;
>>   	struct drm_bridge *panel_bridge;
>> +	struct device_node *host_node;
>>   	struct gpio_desc *enable_gpio;
>>   	struct regulator *vdd1;
>>   	struct regulator *vdd2;
>>   	struct regulator *vdd3;
>> +	int dsi_lanes;
>>   };
>>   
>>   static inline struct chipone *bridge_to_chipone(struct drm_bridge *bridge)
>> @@ -235,6 +237,11 @@ static void chipone_atomic_enable(struct drm_bridge *bridge,
>>   	/* dsi specific sequence */
>>   	ICN6211_DSI(icn, SYNC_EVENT_DLY, 0x80);
>>   	ICN6211_DSI(icn, HFP_MIN, hfp & 0xff);
>> +
>> +	/* DSI data lane count */
>> +	ICN6211_DSI(icn, DSI_CTRL,
>> +		    DSI_CTRL_UNKNOWN | DSI_CTRL_DSI_LANES(icn->dsi_lanes - 1));
>> +
>>   	ICN6211_DSI(icn, MIPI_PD_CK_LANE, 0xa0);
>>   	ICN6211_DSI(icn, PLL_CTRL(12), 0xff);
>>   
>> @@ -354,6 +361,8 @@ static const struct drm_bridge_funcs chipone_bridge_funcs = {
>>   static int chipone_parse_dt(struct chipone *icn)
>>   {
>>   	struct device *dev = icn->dev;
>> +	struct drm_bridge *panel_bridge;
>> +	struct device_node *endpoint;
>>   	struct drm_panel *panel;
>>   	int ret;
>>   
>> @@ -390,13 +399,26 @@ static int chipone_parse_dt(struct chipone *icn)
>>   		return PTR_ERR(icn->enable_gpio);
>>   	}
>>   
>> -	ret = drm_of_find_panel_or_bridge(dev->of_node, 1, 0, &panel, NULL);
>> -	if (ret)
>> +	endpoint = of_graph_get_endpoint_by_regs(dev->of_node, 0, 0);
>> +	icn->dsi_lanes = of_property_count_u32_elems(endpoint, "data-lanes");
>> +	icn->host_node = of_graph_get_remote_port_parent(endpoint);
>> +	of_node_put(endpoint);
>> +
>> +	if (icn->dsi_lanes < 0 || icn->dsi_lanes > 4)
>> +		return -EINVAL;
>> +	if (!icn->host_node)
>> +		return -ENODEV;
>> +
>> +	ret = drm_of_find_panel_or_bridge(dev->of_node, 1, 0, &panel, &panel_bridge);
>> +	if (ret < 0)
>>   		return ret;
>> +	if (panel) {
>> +		panel_bridge = devm_drm_panel_bridge_add(dev, panel);
>> +		if (IS_ERR(panel_bridge))
>> +			return PTR_ERR(panel_bridge);
>> +	}
>>
>> -	icn->panel_bridge = devm_drm_panel_bridge_add(dev, panel);
>> -	if (IS_ERR(icn->panel_bridge))
>> -		return PTR_ERR(icn->panel_bridge);
>> +	icn->panel_bridge = panel_bridge;
> 
> It looks like you're doing more than what you said in the commit log
> here? There's at least a change on the error condition for
> drm_of_find_panel_or_bridge, some reworking of the drm_panel_bridge_add
> call, plus the data-lanes property parsing you were mentioning.
> 
> All those should be separate patches

Actually, I think I can drop this panel_bridge hunk too, which leaves 
only the lane count in this patch.