Re: [resend PATCH v6 12/12] drm/mediatek: Add support for mmsys through a pdev

[Matthias Brugger]

On 09/12/2019 06:34, CK Hu wrote:
> Hi, Matthias:
> 
> On Sat, 2019-12-07 at 23:47 +0100, matthias.bgg@xxxxxxxxxx wrote:
>> From: Matthias Brugger <mbrugger@xxxxxxxx>
>>
>> The MMSYS subsystem includes clocks and drm components.
>> This patch adds an initailization path through a platform device
>> for the clock part, so that both drivers get probed from the same
>> device tree compatible.
> 
> You've switched mt6779 and mt6797 clock driver to platform device
> probing, but you does not probe then in drm driver, so your design is to
> let mmsys clock not work if drm driver is not enabled? It's fine for me
> because it seems that drm driver is the only user of mmsys clock now.
> 

Exactly. The mmsys clocks are only needed for the drm driver. Therefor we only
probe them when probing the drm driver.

Regards,
Matthias


> Regards,
> CK
> 
>>
>> Signed-off-by: Matthias Brugger <mbrugger@xxxxxxxx>
>> ---
>>  drivers/gpu/drm/mediatek/mtk_drm_drv.c | 24 ++++++++++++++++++++++++
>>  drivers/gpu/drm/mediatek/mtk_drm_drv.h |  2 ++
>>  2 files changed, 26 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.c b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
>> index 210455e9f46c..5ada74d8d0c9 100644
>> --- a/drivers/gpu/drm/mediatek/mtk_drm_drv.c
>> +++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
>> @@ -186,6 +186,7 @@ static const struct mtk_mmsys_driver_data mt2701_mmsys_driver_data = {
>>  	.ext_path = mt2701_mtk_ddp_ext,
>>  	.ext_len = ARRAY_SIZE(mt2701_mtk_ddp_ext),
>>  	.shadow_register = true,
>> +	.clk_drv_name = "clk-mt2701-mm",
>>  };
>>  
>>  static const struct mtk_mmsys_driver_data mt2712_mmsys_driver_data = {
>> @@ -195,6 +196,7 @@ static const struct mtk_mmsys_driver_data mt2712_mmsys_driver_data = {
>>  	.ext_len = ARRAY_SIZE(mt2712_mtk_ddp_ext),
>>  	.third_path = mt2712_mtk_ddp_third,
>>  	.third_len = ARRAY_SIZE(mt2712_mtk_ddp_third),
>> +	.clk_drv_name = "clk-mt2712-mm",
>>  };
>>  
>>  static const struct mtk_mmsys_driver_data mt8173_mmsys_driver_data = {
>> @@ -202,6 +204,7 @@ static const struct mtk_mmsys_driver_data mt8173_mmsys_driver_data = {
>>  	.main_len = ARRAY_SIZE(mt8173_mtk_ddp_main),
>>  	.ext_path = mt8173_mtk_ddp_ext,
>>  	.ext_len = ARRAY_SIZE(mt8173_mtk_ddp_ext),
>> +	.clk_drv_name = "clk-mt8173-mm",
>>  };
>>  
>>  static int mtk_drm_kms_init(struct drm_device *drm)
>> @@ -499,6 +502,24 @@ static int mtk_drm_probe(struct platform_device *pdev)
>>  	INIT_WORK(&private->commit.work, mtk_atomic_work);
>>  	private->data = of_device_get_match_data(dev);
>>  
>> +	/*
>> +	 * MMSYS includes apart from components management a block providing
>> +	 * clocks for the subsystem. We probe this clock driver via a platform
>> +	 * device.
>> +	 */
>> +	if (private->data->clk_drv_name) {
>> +		private->clk_dev = platform_device_register_data(dev,
>> +						private->data->clk_drv_name, -1,
>> +						NULL, 0);
>> +
>> +		if (IS_ERR(private->clk_dev)) {
>> +			dev_err(dev, "failed to register %s platform device\n",
>> +				private->data->clk_drv_name);
>> +
>> +			return PTR_ERR(private->clk_dev);
>> +		}
>> +	}
>> +
>>  	private->config_regs = syscon_node_to_regmap(dev->of_node);
>>  	if (IS_ERR(private->config_regs))
>>  		return PTR_ERR(private->config_regs);
>> @@ -605,6 +626,9 @@ static int mtk_drm_remove(struct platform_device *pdev)
>>  	for (i = 0; i < DDP_COMPONENT_ID_MAX; i++)
>>  		of_node_put(private->comp_node[i]);
>>  
>> +	if (private->clk_dev)
>> +		platform_device_unregister(private->clk_dev);
>> +
>>  	return 0;
>>  }
>>  
>> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.h b/drivers/gpu/drm/mediatek/mtk_drm_drv.h
>> index 63a121577dcb..8fe9136adc38 100644
>> --- a/drivers/gpu/drm/mediatek/mtk_drm_drv.h
>> +++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.h
>> @@ -29,11 +29,13 @@ struct mtk_mmsys_driver_data {
>>  	unsigned int third_len;
>>  
>>  	bool shadow_register;
>> +	const char *clk_drv_name;
>>  };
>>  
>>  struct mtk_drm_private {
>>  	struct drm_device *drm;
>>  	struct device *dma_dev;
>> +	struct platform_device *clk_dev;
>>  
>>  	unsigned int num_pipes;
>>  
> 
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