[PATCH 3/7] drm/exynos: add IOMMU support to drm fimd

[Inki Dae]

> -----Original Message-----
> From: Prathyush K [mailto:prathyush.k at samsung.com]
> Sent: Wednesday, July 11, 2012 6:40 PM
> To: dri-devel at lists.freedesktop.org
> Cc: prathyush at chromium.org; m.szyprowski at samsung.com;
inki.dae at samsung.com;
> subash.ramaswamy at linaro.org
> Subject: [PATCH 3/7] drm/exynos: add IOMMU support to drm fimd
> 
> This patch adds device tree based IOMMU support to DRM FIMD. During
> probe, the driver searches for a 'sysmmu' field in the device node. The
> sysmmu field points to the corresponding sysmmu device of fimd.
> This sysmmu device is retrieved and set as fimd's sysmmu. The common
> IOMMU mapping created during DRM init is then attached to drm fimd.
> 
> Signed-off-by: Prathyush K <prathyush.k at samsung.com>
> ---
>  drivers/gpu/drm/exynos/exynos_drm_fimd.c |   54
> +++++++++++++++++++++++++++++-
>  1 files changed, 53 insertions(+), 1 deletions(-)
> 
> diff --git a/drivers/gpu/drm/exynos/exynos_drm_fimd.c
> b/drivers/gpu/drm/exynos/exynos_drm_fimd.c
> index 15b5286..6d4048a 100644
> --- a/drivers/gpu/drm/exynos/exynos_drm_fimd.c
> +++ b/drivers/gpu/drm/exynos/exynos_drm_fimd.c
> @@ -19,7 +19,7 @@
>  #include <linux/clk.h>
>  #include <linux/pm_runtime.h>
>  #include <linux/of.h>
> -
> +#include <linux/of_platform.h>
>  #include <drm/exynos_drm.h>
>  #include <plat/regs-fb-v4.h>
> 
> @@ -790,12 +790,56 @@ static int fimd_power_on(struct fimd_context *ctx,
> bool enable)
>  }
> 
>  #ifdef CONFIG_OF
> +
> +#ifdef CONFIG_EXYNOS_IOMMU
> +static int iommu_init(struct device *dev)
> +{
> +	struct platform_device *pds;
> +	struct device_node *dn, *dns;
> +	const __be32 *parp;
> +	int ret;
> +
> +	dn = dev->of_node;
> +	parp = of_get_property(dn, "sysmmu", NULL);
> +	if (parp == NULL) {
> +		dev_err(dev, "failed to find sysmmu property\n");
> +		return -EINVAL;
> +	}
> +	dns = of_find_node_by_phandle(be32_to_cpup(parp));
> +	if (dns == NULL) {
> +		dev_err(dev, "failed to find sysmmu node\n");
> +		return -EINVAL;
> +	}
> +	pds = of_find_device_by_node(dns);
> +	if (pds == NULL) {
> +		dev_err(dev, "failed to find sysmmu platform device\n");
> +		return -EINVAL;
> +	}
> +
> +	platform_set_sysmmu(&pds->dev, dev);
> +	dev->dma_parms = kzalloc(sizeof(*dev->dma_parms), GFP_KERNEL);
> +	if (!dev->dma_parms) {
> +		dev_err(dev, "failed to allocate dma parms\n");
> +		return -ENOMEM;
> +	}
> +	dma_set_max_seg_size(dev, 0xffffffffu);
> +
> +	ret = arm_iommu_attach_device(dev, exynos_drm_common_mapping);

where is exynos_drm_common_mapping declared? you can get this point using
exynos_drm_private structure.


> +	if (ret) {
> +		dev_err(dev, "failed to attach device\n");
> +		return ret;
> +	}
> +	return 0;
> +}
> +#endif
> +

with your patch, we can use iommu feature only with device tree. I think
iommu feature should be used commonly.


>  static struct exynos_drm_fimd_pdata *drm_fimd_dt_parse_pdata(struct
> device *dev)
>  {
>  	struct device_node *np = dev->of_node;
>  	struct device_node *disp_np;
>  	struct exynos_drm_fimd_pdata *pd;
>  	u32 data[4];
> +	int ret;
> 
>  	pd = kzalloc(sizeof(*pd), GFP_KERNEL);
>  	if (!pd) {
> @@ -803,6 +847,14 @@ static struct exynos_drm_fimd_pdata
> *drm_fimd_dt_parse_pdata(struct device *dev)
>  		return ERR_PTR(-ENOMEM);
>  	}
> 
> +#ifdef CONFIG_EXYNOS_IOMMU

and please avoid such #ifdef in device driver.

> +	ret = iommu_init(dev);
> +	if (ret) {
> +		dev_err(dev, "failed to initialize iommu\n");
> +		return ERR_PTR(ret);
> +	}
> +#endif
> +
>  	if (of_get_property(np, "samsung,fimd-vidout-rgb", NULL))
>  		pd->vidcon0 |= VIDCON0_VIDOUT_RGB | VIDCON0_PNRMODE_RGB;
>  	if (of_get_property(np, "samsung,fimd-vidout-tv", NULL))
> --
> 1.7.0.4