2021-04-15 00:27:47

by Rex-BC Chen (陳柏辰)

Subject: [v2,PATCH 0/3] mt8183 dpi supports dual edge

v2:
modify unused code

v1:
DPI can sample on falling, rising or both edge.
When DPI sample the data both rising and falling edge.
It can reduce half data io pins.

Rex-BC Chen (3):
drm/mediatek: dpi dual edge sample mode support
drm/mediatek: config mt8183 driver data to support dual edge sample
drm/mediatek: dpi: add bus format negotiation

drivers/gpu/drm/mediatek/mtk_dpi.c | 102 +++++++++++++++++++++++++++--
1 file changed, 97 insertions(+), 5 deletions(-)

--
2.18.0

2021-04-15 00:29:00

by Rex-BC Chen (陳柏辰)

Subject: [v2,PATCH 1/3] drm/mediatek: dpi dual edge sample mode support

DPI can sample on falling, rising or both edge.
When DPI sample the data both rising and falling edge.
It can reduce half data io pins.

Signed-off-by: Jitao Shi <[email protected]>
Signed-off-by: Rex-BC Chen <[email protected]>
---
drivers/gpu/drm/mediatek/mtk_dpi.c | 12 ++++++++++++
1 file changed, 12 insertions(+)

diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c b/drivers/gpu/drm/mediatek/mtk_dpi.c
index b05f900d9322..21a3a7b78835 100644
--- a/drivers/gpu/drm/mediatek/mtk_dpi.c
+++ b/drivers/gpu/drm/mediatek/mtk_dpi.c
@@ -83,6 +83,7 @@ struct mtk_dpi {
struct pinctrl *pinctrl;
struct pinctrl_state *pins_gpio;
struct pinctrl_state *pins_dpi;
+ bool ddr_edge_sel;
int refcount;
};

@@ -121,6 +122,7 @@ struct mtk_dpi_conf {
unsigned int (*cal_factor)(int clock);
u32 reg_h_fre_con;
bool edge_sel_en;
+ bool dual_edge;
};

static void mtk_dpi_mask(struct mtk_dpi *dpi, u32 offset, u32 val, u32 mask)
@@ -380,6 +382,15 @@ static void mtk_dpi_config_color_format(struct mtk_dpi *dpi,
}
}

+static void mtk_dpi_dual_edge(struct mtk_dpi *dpi)
+{
+ if (dpi->conf->dual_edge) {
+ mtk_dpi_mask(dpi, DPI_DDR_SETTING, DDR_EN | DDR_4PHASE,
+ DDR_EN | DDR_4PHASE);
+ mtk_dpi_mask(dpi, DPI_OUTPUT_SETTING, dpi->ddr_edge_sel ? EDGE_SEL : 0, EDGE_SEL);
+ }
+}
+
static void mtk_dpi_power_off(struct mtk_dpi *dpi)
{
if (WARN_ON(dpi->refcount == 0))
@@ -518,6 +529,7 @@ static int mtk_dpi_set_display_mode(struct mtk_dpi *dpi,
mtk_dpi_config_yc_map(dpi, dpi->yc_map);
mtk_dpi_config_color_format(dpi, dpi->color_format);
mtk_dpi_config_2n_h_fre(dpi);
+ mtk_dpi_dual_edge(dpi);
mtk_dpi_config_disable_edge(dpi);
mtk_dpi_sw_reset(dpi, false);

--
2.18.0

2021-04-19 07:38:21

by Neil Armstrong

Subject: Re: [v2,PATCH 1/3] drm/mediatek: dpi dual edge sample mode support

Hi,

On 14/04/2021 15:35, Rex-BC Chen wrote:
> DPI can sample on falling, rising or both edge.
> When DPI sample the data both rising and falling edge.
> It can reduce half data io pins.
>
> Signed-off-by: Jitao Shi <[email protected]>
> Signed-off-by: Rex-BC Chen <[email protected]>
> ---
> drivers/gpu/drm/mediatek/mtk_dpi.c | 12 ++++++++++++
> 1 file changed, 12 insertions(+)
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c b/drivers/gpu/drm/mediatek/mtk_dpi.c
> index b05f900d9322..21a3a7b78835 100644
> --- a/drivers/gpu/drm/mediatek/mtk_dpi.c
> +++ b/drivers/gpu/drm/mediatek/mtk_dpi.c
> @@ -83,6 +83,7 @@ struct mtk_dpi {
> struct pinctrl *pinctrl;
> struct pinctrl_state *pins_gpio;
> struct pinctrl_state *pins_dpi;
> + bool ddr_edge_sel;
> int refcount;
> };
>
> @@ -121,6 +122,7 @@ struct mtk_dpi_conf {
> unsigned int (*cal_factor)(int clock);
> u32 reg_h_fre_con;
> bool edge_sel_en;
> + bool dual_edge;
> };
>
> static void mtk_dpi_mask(struct mtk_dpi *dpi, u32 offset, u32 val, u32 mask)
> @@ -380,6 +382,15 @@ static void mtk_dpi_config_color_format(struct mtk_dpi *dpi,
> }
> }
>
> +static void mtk_dpi_dual_edge(struct mtk_dpi *dpi)
> +{
> + if (dpi->conf->dual_edge) {
> + mtk_dpi_mask(dpi, DPI_DDR_SETTING, DDR_EN | DDR_4PHASE,
> + DDR_EN | DDR_4PHASE);
> + mtk_dpi_mask(dpi, DPI_OUTPUT_SETTING, dpi->ddr_edge_sel ? EDGE_SEL : 0, EDGE_SEL);
> + }
> +}
> +

By using the downstream code as reference:

- clk_set_rate(dpi->pixel_clk, vm.pixelclock);
+ clk_set_rate(dpi->pixel_clk, vm.pixelclock * (dpi->conf->dual_edge ? 2 : 1));

is missing in mtk_dpi_set_display_mode()

> static void mtk_dpi_power_off(struct mtk_dpi *dpi)
> {
> if (WARN_ON(dpi->refcount == 0))
> @@ -518,6 +529,7 @@ static int mtk_dpi_set_display_mode(struct mtk_dpi *dpi,
> mtk_dpi_config_yc_map(dpi, dpi->yc_map);
> mtk_dpi_config_color_format(dpi, dpi->color_format);
> mtk_dpi_config_2n_h_fre(dpi);
> + mtk_dpi_dual_edge(dpi);
> mtk_dpi_config_disable_edge(dpi);
> mtk_dpi_sw_reset(dpi, false);
>
>

Neil

2021-04-29 02:30:35

by Rex-BC Chen (陳柏辰)

Subject: Re: [v2,PATCH 1/3] drm/mediatek: dpi dual edge sample mode support

On Mon, 2021-04-19 at 09:36 +0200, Neil Armstrong wrote:
> Hi,
>
> On 14/04/2021 15:35, Rex-BC Chen wrote:
> > DPI can sample on falling, rising or both edge.
> > When DPI sample the data both rising and falling edge.
> > It can reduce half data io pins.
> >
> > Signed-off-by: Jitao Shi <[email protected]>
> > Signed-off-by: Rex-BC Chen <[email protected]>
> > ---
> > drivers/gpu/drm/mediatek/mtk_dpi.c | 12 ++++++++++++
> > 1 file changed, 12 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c
> > b/drivers/gpu/drm/mediatek/mtk_dpi.c
> > index b05f900d9322..21a3a7b78835 100644
> > --- a/drivers/gpu/drm/mediatek/mtk_dpi.c
> > +++ b/drivers/gpu/drm/mediatek/mtk_dpi.c
> > @@ -83,6 +83,7 @@ struct mtk_dpi {
> > struct pinctrl *pinctrl;
> > struct pinctrl_state *pins_gpio;
> > struct pinctrl_state *pins_dpi;
> > + bool ddr_edge_sel;
> > int refcount;
> > };
> >
> > @@ -121,6 +122,7 @@ struct mtk_dpi_conf {
> > unsigned int (*cal_factor)(int clock);
> > u32 reg_h_fre_con;
> > bool edge_sel_en;
> > + bool dual_edge;
> > };
> >
> > static void mtk_dpi_mask(struct mtk_dpi *dpi, u32 offset, u32 val,
> > u32 mask)
> > @@ -380,6 +382,15 @@ static void mtk_dpi_config_color_format(struct
> > mtk_dpi *dpi,
> > }
> > }
> >
> > +static void mtk_dpi_dual_edge(struct mtk_dpi *dpi)
> > +{
> > + if (dpi->conf->dual_edge) {
> > + mtk_dpi_mask(dpi, DPI_DDR_SETTING, DDR_EN | DDR_4PHASE,
> > + DDR_EN | DDR_4PHASE);
> > + mtk_dpi_mask(dpi, DPI_OUTPUT_SETTING, dpi->ddr_edge_sel
> > ? EDGE_SEL : 0, EDGE_SEL);
> > + }
> > +}
> > +
>
> By using the downstream code as reference:
>
> - clk_set_rate(dpi->pixel_clk, vm.pixelclock);
> + clk_set_rate(dpi->pixel_clk, vm.pixelclock * (dpi->conf-
> >dual_edge ? 2 : 1));
>
> is missing in mtk_dpi_set_display_mode()
>
Hello Neil,

Thanks for helping checking this.
I will add this modification for next patch.

BRs,
Rex-BC Chen
> > static void mtk_dpi_power_off(struct mtk_dpi *dpi)
> > {
> > if (WARN_ON(dpi->refcount == 0))
> > @@ -518,6 +529,7 @@ static int mtk_dpi_set_display_mode(struct
> > mtk_dpi *dpi,
> > mtk_dpi_config_yc_map(dpi, dpi->yc_map);
> > mtk_dpi_config_color_format(dpi, dpi->color_format);
> > mtk_dpi_config_2n_h_fre(dpi);
> > + mtk_dpi_dual_edge(dpi);
> > mtk_dpi_config_disable_edge(dpi);
> > mtk_dpi_sw_reset(dpi, false);
> >
> >
>
> Neil