[PATCH] drm: exynos: add iommu support in hdmi driver with dt enabled

[Rahul Sharma]

On Wed, Nov 7, 2012 at 3:11 PM, Inki Dae <inki.dae at samsung.com> wrote:
>
>
> 2012/11/7 Leela Krishna Amudala <l.krishna at samsung.com>
>>
>> Hello Rahul,
>>
>> On Mon, Nov 5, 2012 at 2:32 PM, Rahul Sharma <rahul.sharma at samsung.com>
>> wrote:
>> > This patch adds iommu support for hdmi driver with device tree based
>> > search. It searches for sysmmu property in hdmi dt node to get tv
>> > iommu device pointer which will be used to configure iommu hw interface.
>> >
>> > This patch is based on "exynos-drm-next-iommu" branch at
>> > http://git.kernel.org/?p=linux/kernel/git/daeinki/drm-exynos.git
>> >
>> > This patch is having dependency on  linux-samsung-soc patchset named
>> > "add dt based support for iommu for hdmi"
>> >
>> > Signed-off-by: Rahul Sharma <rahul.sharma at samsung.com>
>> > Signed-off-by: Prathyush K <prathyush.k at samsung.com>
>> > ---
>> >  drivers/gpu/drm/exynos/exynos_hdmi.c |   35
>> > ++++++++++++++++++++++++++++++++++
>> >  1 files changed, 35 insertions(+), 0 deletions(-)
>> >
>> > diff --git a/drivers/gpu/drm/exynos/exynos_hdmi.c
>> > b/drivers/gpu/drm/exynos/exynos_hdmi.c
>> > index d1a1d71..ee110c9 100644
>> > --- a/drivers/gpu/drm/exynos/exynos_hdmi.c
>> > +++ b/drivers/gpu/drm/exynos/exynos_hdmi.c
>> > @@ -34,7 +34,9 @@
>> >  #include <linux/regulator/consumer.h>
>> >  #include <linux/io.h>
>> >  #include <linux/of_gpio.h>
>> > +#include <linux/of_platform.h>
>> >  #include <plat/gpio-cfg.h>
>> > +#include <mach/sysmmu.h>
>> >
>> >  #include <drm/exynos_drm.h>
>> >
>> > @@ -2275,6 +2277,34 @@ void hdmi_attach_hdmiphy_client(struct i2c_client
>> > *hdmiphy)
>> >  }
>> >
>> >  #ifdef CONFIG_OF
>> > +
>> > +static int drm_hdmi_dt_init_iommu(struct device *dev)
>> > +{
>> > +       struct platform_device *pds;
>> > +       struct device_node *dn, *dns;
>> > +       const __be32 *parp;
>> > +
>> > +       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);
>> > +       return 0;
>> > +}
>> > +
>>
>> As a part of adding iommu support to FIMD driver, we have to implement
>> the same function in FIMD driver also, which makes code replication.
>> So, it would be better to move this function out of this file and put
>> it in a common drm file so that FIMD also can use it.
>>
>
> I tend to agree with you but I think it's better to move it into
> drivers/iommu/exynos-iommu.c because IOMMU units could be used by device
> driver based on not only DRM but also V4L2.
>
> Thanks,
> Inki Dae
>

Mr Dae,

Do you mean, we should export this function from
drivers/iommu/exynos-iommu.c? How
can I add it there ? To me it looks very much iommu client specific
code as it is tryng to parse
its DT node for "sysmmu" property.

I was thinking of putting it into exynos_drm_iommu.c which is visible
to hdmi and fimd both.

regards,
Rahul Sharma

>>
>> Best Wishes,
>> Leela Krishna Amudala.
>>
>>
>> >  static struct s5p_hdmi_platform_data *drm_hdmi_dt_parse_pdata
>> >                                         (struct device *dev)
>> >  {
>> > @@ -2294,6 +2324,11 @@ static struct s5p_hdmi_platform_data
>> > *drm_hdmi_dt_parse_pdata
>> >                 goto err_data;
>> >         }
>> >
>> > +       if (drm_hdmi_dt_init_iommu(dev)){
>> > +               DRM_ERROR("no sysmmu property found\n");
>> > +               goto err_data;
>> > +       }
>> > +
>> >         pd->hpd_gpio = of_get_named_gpio_flags(np, "hpd-gpio", 0,
>> > &flags);
>> >
>> >         return pd;
>> > --
>> > 1.7.0.4
>> >
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