[PATCH v4 1/5] drm/rockchip: Add basic drm driver

[Mark yao]

On 2014年09月22日 22:43, Arnd Bergmann wrote:
> On Monday 22 September 2014 18:48:54 Mark yao wrote:
>> diff --git a/drivers/gpu/drm/rockchip/Kconfig b/drivers/gpu/drm/rockchip/Kconfig
>> new file mode 100644
>> index 0000000..7146c80
>> --- /dev/null
>> +++ b/drivers/gpu/drm/rockchip/Kconfig
>> @@ -0,0 +1,19 @@
>> +config DRM_ROCKCHIP
>> +	tristate "DRM Support for Rockchip"
>> +	depends on DRM && ROCKCHIP_IOMMU
>> +	select ARM_DMA_USE_IOMMU
>> +	select IOMMU_API
>> +	select DRM_KMS_HELPER
>> +	select DRM_KMS_FB_HELPER
>> +	select DRM_PANEL
>> +	select FB_CFB_FILLRECT
>> +	select FB_CFB_COPYAREA
>> +	select FB_CFB_IMAGEBLIT
>> +	select VT_HW_CONSOLE_BINDING if FRAMEBUFFER_CONSOLE
>> +	select VIDEOMODE_HELPERS
> Be careful with 'select', at least some of these should be 'depends on'.
> In particular IOMMU_API and ARM_DMA_USE_IOMMU, but possibly others
> as well. Just check how the symbols are used normally, if you get this
> wrong, we can end up with incorrect dependencies or loops.
>
I see, I will change it.
>> diff --git a/drivers/gpu/drm/rockchip/Makefile b/drivers/gpu/drm/rockchip/Makefile
>> new file mode 100644
>> index 0000000..6e6d468
>> --- /dev/null
>> +++ b/drivers/gpu/drm/rockchip/Makefile
>> @@ -0,0 +1,10 @@
>> +#
>> +# Makefile for the drm device driver.  This driver provides support for the
>> +# Direct Rendering Infrastructure (DRI) in XFree86 4.1.0 and higher.
>> +
>> +ccflags-y := -Iinclude/drm -Idrivers/gpu/drm/rockchip
> The second one should not be required.
Sure, I will change it.
>> +static int rockchip_drm_load(struct drm_device *drm_dev, unsigned long flags)
>> +{
>> +	struct rockchip_drm_private *private;
>> +	struct dma_iommu_mapping *mapping;
>> +	struct device *dev = drm_dev->dev;
>> +	int ret;
>> +
>> +	private = devm_kzalloc(drm_dev->dev, sizeof(*private), GFP_KERNEL);
>> +	if (!private)
>> +		return -ENOMEM;
>> +
>> +	dev_set_drvdata(drm_dev->dev, dev);
>> +	drm_dev->dev_private = private;
>> +
>> +	drm_mode_config_init(drm_dev);
>> +
>> +	rockchip_drm_mode_config_init(drm_dev);
>> +
>> +	dev->dma_parms = devm_kzalloc(dev, sizeof(*dev->dma_parms),
>> +				      GFP_KERNEL);
>> +	if (!dev->dma_parms) {
>> +		ret = -ENOMEM;
>> +		goto err_config_cleanup;
>> +	}
>> +
>> +	/* TODO(djkurtz): fetch the mapping start/size from somewhere */
>> +	mapping = arm_iommu_create_mapping(&platform_bus_type, 0x10000000,
>> +					   SZ_1G);
>> +	if (IS_ERR(mapping)) {
>> +		ret = PTR_ERR(mapping);
>> +		goto err_config_cleanup;
>> +	}
>> +
>> +	dma_set_coherent_mask(dev, DMA_BIT_MASK(32));
> This is the default coherent mask. If you call this function, you
> should normally check the return value, or call dma_set_mask first,
> which you apparently don't do here, and in another place in this
> patch.
>
> 	Arnd
>
>
>