by Matthias Brugger

[permalink] [raw]

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

On 09/12/2019 06:34, CK Hu wrote:
> Hi, Matthias:
>
> On Sat, 2019-12-07 at 23:47 +0100, [email protected] wrote:
>> From: Matthias Brugger <[email protected]>
>>
>> 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 <[email protected]>
>> ---
>> 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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