Re: [RFC 2/3] drm/mediatek: add support for Mediatek SoC MT2701

YT Shen
2016-05-18T08:33:30Z

Hi Emil,

On Tue, 2016-05-17 at 10:55 +0100, Emil Velikov wrote:
> Hi YT Shen,
>
> On 12 May 2016 at 12:49, <yt.shen@mediatek.com> wrote:
> > From: YT Shen <yt.shen@mediatek.com>
> >
> > This patch add support for the Mediatek MT2701 DISP subsystem.
> > There is only one OVL engine in MT2701, and we have shadow
> > register support here.
> >
> > Signed-off-by: YT Shen <yt.shen@mediatek.com>
> > ---
> > drivers/gpu/drm/mediatek/mtk_disp_ovl.c | 49 ++++++---
> > drivers/gpu/drm/mediatek/mtk_disp_rdma.c | 36 +++++--
> > drivers/gpu/drm/mediatek/mtk_drm_crtc.c | 78 +++++++++-----
> > drivers/gpu/drm/mediatek/mtk_drm_ddp.c | 151 ++++++++++++++++++++-------
> > drivers/gpu/drm/mediatek/mtk_drm_ddp.h | 2 +
> > drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c | 63 +++++++++--
> > drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h | 15 +++
> > drivers/gpu/drm/mediatek/mtk_drm_drv.c | 72 +++++++++++--
> > drivers/gpu/drm/mediatek/mtk_drm_drv.h | 9 ++
> > drivers/gpu/drm/mediatek/mtk_drm_gem.c | 4 +
> > 10 files changed, 373 insertions(+), 106 deletions(-)
> >
> This patch does a bit too many things at once imho
> - Renames existing macros
> - Factors out helper functions - mtk_crtc_ddp_config and alike.
> - Introduces *driver_data for existing hardware and uses it
> - and adds support for the different hardware.
>
> I'm no expert in the area, but it feels like you want to split things
> roughly as per above.
> A rather serious mali note and some "this should be const" follow
> suggestions inline.
Thanks for your suggestions. I will split this patch into several small
patches. They are easier to understand, and easier to review.
>
>
> >
> > +static struct mtk_ddp_comp_driver_data mt2701_ovl_driver_data = {
> > + .ovl = {0x0040, 1 << 12, 0}
> > +};
> > +
> > +static struct mtk_ddp_comp_driver_data mt8173_ovl_driver_data = {
> > + .ovl = {0x0f40, 0, 1 << 12}
> > +};
> > +
> These two should be const right ?
Yes, they should.
>
>
> >
> > +static struct mtk_ddp_comp_driver_data mt2701_rdma_driver_data = {
> > + .rdma_fifo_pseudo_size = SZ_4K,
> > +};
> > +
> > +static struct mtk_ddp_comp_driver_data mt8173_rdma_driver_data = {
> > + .rdma_fifo_pseudo_size = SZ_8K,
> > +};
> > +
> Same here.
OK.
>
>
> >
> > -#define MUTEX_MOD_DISP_OVL0 BIT(11)
> > -#define MUTEX_MOD_DISP_OVL1 BIT(12)
> > -#define MUTEX_MOD_DISP_RDMA0 BIT(13)
> > -#define MUTEX_MOD_DISP_RDMA1 BIT(14)
> > -#define MUTEX_MOD_DISP_RDMA2 BIT(15)
> > -#define MUTEX_MOD_DISP_WDMA0 BIT(16)
> > -#define MUTEX_MOD_DISP_WDMA1 BIT(17)
> > -#define MUTEX_MOD_DISP_COLOR0 BIT(18)
> > -#define MUTEX_MOD_DISP_COLOR1 BIT(19)
> > -#define MUTEX_MOD_DISP_AAL BIT(20)
> > -#define MUTEX_MOD_DISP_GAMMA BIT(21)
> > -#define MUTEX_MOD_DISP_UFOE BIT(22)
> > -#define MUTEX_MOD_DISP_PWM0 BIT(23)
> > -#define MUTEX_MOD_DISP_PWM1 BIT(24)
> > -#define MUTEX_MOD_DISP_OD BIT(25)
> > +#define MUTEX_MOD_MT8173_DISP_OVL0 BIT(11)
> > +#define MUTEX_MOD_MT8173_DISP_OVL1 BIT(12)
> > +#define MUTEX_MOD_MT8173_DISP_RDMA0 BIT(13)
> > +#define MUTEX_MOD_MT8173_DISP_RDMA1 BIT(14)
> > +#define MUTEX_MOD_MT8173_DISP_RDMA2 BIT(15)
> > +#define MUTEX_MOD_MT8173_DISP_WDMA0 BIT(16)
> > +#define MUTEX_MOD_MT8173_DISP_WDMA1 BIT(17)
> > +#define MUTEX_MOD_MT8173_DISP_COLOR0 BIT(18)
> > +#define MUTEX_MOD_MT8173_DISP_COLOR1 BIT(19)
> > +#define MUTEX_MOD_MT8173_DISP_AAL BIT(20)
> > +#define MUTEX_MOD_MT8173_DISP_GAMMA BIT(21)
> > +#define MUTEX_MOD_MT8173_DISP_UFOE BIT(22)
> > +#define MUTEX_MOD_MT8173_DISP_PWM0 BIT(23)
> > +#define MUTEX_MOD_MT8173_DISP_PWM1 BIT(24)
> > +#define MUTEX_MOD_MT8173_DISP_OD BIT(25)
> > +
> > +#define MUTEX_MOD_MT2701_DISP_OVL BIT(3)
> > +#define MUTEX_MOD_MT2701_DISP_WDMA BIT(6)
> > +#define MUTEX_MOD_MT2701_DISP_COLOR BIT(7)
> > +#define MUTEX_MOD_MT2701_DISP_BLS BIT(9)
> > +#define MUTEX_MOD_MT2701_DISP_RDMA0 BIT(10)
> > +#define MUTEX_MOD_MT2701_DISP_RDMA1 BIT(12)
> >
> Even though the driver not does use a unique prefix/namespace for
> these macros (which it should imho), it's better to keep the hardware
> name/part first. Ideally the rename will be a separate patch.
OK, I will rename the macros and put it in a separate patch.
>
>
> > @@ -131,6 +153,32 @@ static const struct mtk_ddp_comp_match mtk_ddp_matches[DDP_COMPONENT_ID_MAX] = {
> > [DDP_COMPONENT_WDMA1] = { MTK_DISP_WDMA, 1, NULL },
> > };
> >
> > +static struct mtk_ddp_comp_driver_data mt2701_color_driver_data = {
> > + .color_offset = 0x0f00,
> > +};
> > +
> > +static struct mtk_ddp_comp_driver_data mt8173_color_driver_data = {
> > + .color_offset = 0x0c00,
> > +};
> > +
> const again ? You can even tweak the *_get_driver_data helpers, to
> return const struct foo*, and resolve the odd warning that the
> compiler will give you.
OK, I will do it in the next version.
>
>
> > struct mtk_ddp_comp {
> > struct clk *clk;
> > void __iomem *regs;
> > @@ -82,6 +96,7 @@ struct mtk_ddp_comp {
> > struct device *larb_dev;
> > enum mtk_ddp_comp_id id;
> > const struct mtk_ddp_comp_funcs *funcs;
> > + struct mtk_ddp_comp_driver_data *data;
> const
OK.
>
>
> > +static struct mtk_mmsys_driver_data mt2701_mmsys_driver_data = {
> > + .main_path = mtk_ddp_main_2701,
> > + .main_len = ARRAY_SIZE(mtk_ddp_main_2701),
> > + .ext_path = mtk_ddp_ext_2701,
> > + .ext_len = ARRAY_SIZE(mtk_ddp_ext_2701),
> > + .shadow_register = true,
> > +};
> > +
> > +static struct mtk_mmsys_driver_data mt8173_mmsys_driver_data = {
> > + .main_path = mtk_ddp_main_8173,
> > + .main_len = ARRAY_SIZE(mtk_ddp_main_8173),
> > + .ext_path = mtk_ddp_ext_8173,
> > + .ext_len = ARRAY_SIZE(mtk_ddp_ext_8173),
> > + .shadow_register = false,
> > +};
> > +
> const
OK.
>
>
> > @@ -40,6 +48,7 @@ struct mtk_drm_private {
> > void __iomem *config_regs;
> > struct device_node *comp_node[DDP_COMPONENT_ID_MAX];
> > struct mtk_ddp_comp *ddp_comp[DDP_COMPONENT_ID_MAX];
> > + struct mtk_mmsys_driver_data *data;
> const ?
Yes.
>
>
> > @@ -108,6 +108,10 @@ int mtk_drm_gem_dumb_create(struct drm_file *file_priv, struct drm_device *dev,
> > int ret;
> >
> > args->pitch = DIV_ROUND_UP(args->width * args->bpp, 8);
> > + /*
> > + * align to 8 bytes since Mali requires it.
> > + */
> > + args->pitch = ALIGN(args->pitch, 8);
> Are you sure we need this, based on the line just above ?
I think bpp stands for bits per pixel, so width * bpp / 8 simply transfer from bits to bytes, which
cannot guarantee align to 8.

I will remove this align part from the patch, this constraint is not from display controller.
Thanks.

>
> Iirc we had a chat earlier that upstream kernel code should not be
> tailoured for the needs to closed source userspace... seems like the
> comment got removed but the code remained. Philipp Zabel I believe you
> were the person who did the original upstreaming - can we remove this
> hack/workaround and keep it downstream until we have an open-source
> user that requires it ?
>
> Can we have a MAINTAINERS entry for this driver ?
>
> Thanks
> Emil