Hi Joel,
We have released related datasheet and update these registers description.
SCU300: Clock Selection Register
...
10:8 Soc display clock selection
000b: D-PLL
001b: Reserved
010b: 40MHz from USB 2.0 port1 PHY
011b: GPIOC6
100b: Reserved
101b: E-PLL divided by SCU308[17:12]
110b: M-PLL divided by SCU308[17:12]
111b: H-PLL divided by SCU308[17:12]
SCU308: Clock Selection Register Set 3
17:12 Soc display clock divider selection
000000b: div 1
011011b: div 16
Thanks,
By Tommy
> -----Original Message-----
> From: Tommy Huang
> Sent: Tuesday, April 26, 2022 4:28 PM
> To: Joel Stanley <joel@xxxxxxxxx>
> Cc: David Airlie <airlied@xxxxxxxx>; Daniel Vetter <daniel@xxxxxxxx>; Rob
> Herring <robh+dt@xxxxxxxxxx>; Andrew Jeffery <andrew@xxxxxxxx>;
> linux-aspeed <linux-aspeed@xxxxxxxxxxxxxxxx>; open list:DRM DRIVERS
> <dri-devel@xxxxxxxxxxxxxxxxxxxxx>; devicetree <devicetree@xxxxxxxxxxxxxxx>;
> Linux ARM <linux-arm-kernel@xxxxxxxxxxxxxxxxxxx>; Linux Kernel Mailing List
> <linux-kernel@xxxxxxxxxxxxxxx>; BMC-SW <BMC-SW@xxxxxxxxxxxxxx>
> Subject: RE: [PATCH v1 2/2] drm/aspeed: Add 1024x768 mode for AST2600
>
>
>
> > -----Original Message-----
> > From: Joel Stanley <joel@xxxxxxxxx>
> > Sent: Tuesday, April 26, 2022 3:48 PM
> > To: Tommy Huang <tommy_huang@xxxxxxxxxxxxxx>
> > Cc: David Airlie <airlied@xxxxxxxx>; Daniel Vetter <daniel@xxxxxxxx>;
> > Rob Herring <robh+dt@xxxxxxxxxx>; Andrew Jeffery <andrew@xxxxxxxx>;
> > linux-aspeed <linux-aspeed@xxxxxxxxxxxxxxxx>; open list:DRM DRIVERS
> > <dri-devel@xxxxxxxxxxxxxxxxxxxxx>; devicetree
> > <devicetree@xxxxxxxxxxxxxxx>; Linux ARM
> > <linux-arm-kernel@xxxxxxxxxxxxxxxxxxx>; Linux Kernel Mailing List
> > <linux-kernel@xxxxxxxxxxxxxxx>; BMC-SW <BMC-SW@xxxxxxxxxxxxxx>
> > Subject: Re: [PATCH v1 2/2] drm/aspeed: Add 1024x768 mode for AST2600
> >
> > On Fri, 4 Mar 2022 at 06:32, Tommy Haung
> <tommy_huang@xxxxxxxxxxxxxx>
> > wrote:
> > >
> > > Update the aspeed_gfx_set_clk with display width.
> > > At AST2600, the display clock could be coming from HPLL clock / 16 =
> > > 75MHz. It would fit 1024x768@70Hz.
> > > Another chip will still keep 800x600.
> > >
> > > Signed-off-by: Tommy Haung <tommy_huang@xxxxxxxxxxxxxx>
> > > ---
> > > drivers/gpu/drm/aspeed/aspeed_gfx.h | 12 ++++++----
> > > drivers/gpu/drm/aspeed/aspeed_gfx_crtc.c | 29
> > > ++++++++++++++++++++---- drivers/gpu/drm/aspeed/aspeed_gfx_drv.c
> |
> > > 16 +++++++++++-- drivers/gpu/drm/aspeed/aspeed_gfx_out.c | 14
> > > +++++++++++-
> > > 4 files changed, 60 insertions(+), 11 deletions(-)
> > >
> > > diff --git a/drivers/gpu/drm/aspeed/aspeed_gfx.h
> > > b/drivers/gpu/drm/aspeed/aspeed_gfx.h
> > > index eb4c267cde5e..c7aefee0657a 100644
> > > --- a/drivers/gpu/drm/aspeed/aspeed_gfx.h
> > > +++ b/drivers/gpu/drm/aspeed/aspeed_gfx.h
> > > @@ -109,11 +109,15 @@ int aspeed_gfx_create_output(struct drm_device
> > *drm);
> > > #define CRT_THROD_HIGH(x) ((x) << 8)
> > >
> > > /* SCU control */
> > > -#define SCU_G6_CLK_COURCE 0x300
> > > +#define G6_CLK_SOURCE 0x300
> > > +#define G6_CLK_SOURCE_MASK (BIT(8) | BIT(9) | BIT(10))
> > > +#define G6_CLK_SOURCE_HPLL (BIT(8) | BIT(9) | BIT(10))
> > > +#define G6_CLK_SOURCE_USB BIT(9)
> > > +#define G6_CLK_SEL3 0x308
> > > +#define G6_CLK_DIV_MASK 0x3F000
> >
> > This register is defined in the data sheet as:
> >
> > 17:12 SOC Display clock selection when source is from DisplayPort PHY
> >
> > That doesn't match with what the code is doing. Can you clarify the
> > register definition?
>
> OK. I will clarify it and response it to you.
>
> >
> > > +#define G6_CLK_DIV_16
> > (BIT(16)|BIT(15)|BIT(13)|BIT(12))
> > > +#define G6_USB_40_CLK BIT(9)
> > >
> > > /* GFX FLAGS */
> > > #define CLK_MASK BIT(0)
> > > #define CLK_G6 BIT(0)
> > > -
> > > -#define G6_CLK_MASK (BIT(8) | BIT(9) | BIT(10))
> > > -#define G6_USB_40_CLK BIT(9)
> > > diff --git a/drivers/gpu/drm/aspeed/aspeed_gfx_crtc.c
> > > b/drivers/gpu/drm/aspeed/aspeed_gfx_crtc.c
> > > index a24fab22eac4..5829be9c7c67 100644
> > > --- a/drivers/gpu/drm/aspeed/aspeed_gfx_crtc.c
> > > +++ b/drivers/gpu/drm/aspeed/aspeed_gfx_crtc.c
> > > @@ -23,6 +23,28 @@ drm_pipe_to_aspeed_gfx(struct
> > drm_simple_display_pipe *pipe)
> > > return container_of(pipe, struct aspeed_gfx, pipe); }
> > >
> > > +static void aspeed_gfx_set_clock_source(struct aspeed_gfx *priv,
> > > +int
> > > +mode_width) {
> > > + regmap_update_bits(priv->scu, G6_CLK_SOURCE,
> > G6_CLK_SOURCE_MASK, 0x0);
> > > + regmap_update_bits(priv->scu, G6_CLK_SEL3,
> G6_CLK_DIV_MASK,
> > > +0x0);
> > > +
> > > + switch (mode_width) {
> > > + case 1024:
> > > + /* hpll div 16 = 75Mhz */
> > > + regmap_update_bits(priv->scu, G6_CLK_SOURCE,
> > > + G6_CLK_SOURCE_MASK, G6_CLK_SOURCE_HPLL);
> > > + regmap_update_bits(priv->scu, G6_CLK_SEL3,
> > > + G6_CLK_DIV_MASK, G6_CLK_DIV_16);
> > > + break;
> > > + case 800:
> > > + default:
> > > + /* usb 40Mhz */
> > > + regmap_update_bits(priv->scu, G6_CLK_SOURCE,
> > > + G6_CLK_SOURCE_MASK, G6_CLK_SOURCE_USB);
> > > + break;
> > > + }
> > > +}
> > > +
> > > static int aspeed_gfx_set_pixel_fmt(struct aspeed_gfx *priv, u32
> > > *bpp) {
> > > struct drm_crtc *crtc = &priv->pipe.crtc; @@ -77,12 +99,11
> > > @@ static void aspeed_gfx_disable_controller(struct aspeed_gfx *priv)
> > > regmap_update_bits(priv->scu, priv->dac_reg, BIT(16), 0); }
> > >
> > > -static void aspeed_gfx_set_clk(struct aspeed_gfx *priv)
> > > +static void aspeed_gfx_set_clk(struct aspeed_gfx *priv, int
> > > +mode_width)
> > > {
> > > switch (priv->flags & CLK_MASK) {
> > > case CLK_G6:
> > > - regmap_update_bits(priv->scu, SCU_G6_CLK_COURCE,
> > G6_CLK_MASK, 0x0);
> > > - regmap_update_bits(priv->scu, SCU_G6_CLK_COURCE,
> > G6_CLK_MASK, G6_USB_40_CLK);
> > > + aspeed_gfx_set_clock_source(priv, mode_width);
> > > break;
> > > default:
> > > break;
> > > @@ -99,7 +120,7 @@ static void aspeed_gfx_crtc_mode_set_nofb(struct
> > aspeed_gfx *priv)
> > > if (err)
> > > return;
> > >
> > > - aspeed_gfx_set_clk(priv);
> > > + aspeed_gfx_set_clk(priv, m->hdisplay);
> > >
> > > #if 0
> > > /* TODO: we have only been able to test with the 40MHz USB
> > > clock. The diff --git a/drivers/gpu/drm/aspeed/aspeed_gfx_drv.c
> > > b/drivers/gpu/drm/aspeed/aspeed_gfx_drv.c
> > > index af56ffdccc65..e1a814aebc2d 100644
> > > --- a/drivers/gpu/drm/aspeed/aspeed_gfx_drv.c
> > > +++ b/drivers/gpu/drm/aspeed/aspeed_gfx_drv.c
> > > @@ -110,6 +110,7 @@ static const struct drm_mode_config_funcs
> > > aspeed_gfx_mode_config_funcs = {
> > >
> > > static int aspeed_gfx_setup_mode_config(struct drm_device *drm) {
> > > + struct aspeed_gfx *priv = to_aspeed_gfx(drm);
> > > int ret;
> > >
> > > ret = drmm_mode_config_init(drm); @@ -118,8 +119,18 @@
> > static
> > > int aspeed_gfx_setup_mode_config(struct drm_device *drm)
> > >
> > > drm->mode_config.min_width = 0;
> > > drm->mode_config.min_height = 0;
> > > - drm->mode_config.max_width = 800;
> > > - drm->mode_config.max_height = 600;
> > > +
> > > + switch (priv->flags & CLK_MASK) {
> > > + case CLK_G6:
> > > + drm->mode_config.max_width = 1024;
> > > + drm->mode_config.max_height = 768;
> > > + break;
> > > + default:
> > > + drm->mode_config.max_width = 800;
> > > + drm->mode_config.max_height = 600;
> > > + break;
> > > + }
> > > +
> > > drm->mode_config.funcs = &aspeed_gfx_mode_config_funcs;
> > >
> > > return ret;
> > > @@ -167,6 +178,7 @@ static int aspeed_gfx_load(struct drm_device *drm)
> > > priv->vga_scratch_reg = config->vga_scratch_reg;
> > > priv->throd_val = config->throd_val;
> > > priv->scan_line_max = config->scan_line_max;
> > > + priv->flags = config->gfx_flags;
> > >
> > > priv->scu = syscon_regmap_lookup_by_phandle(np, "syscon");
> > > if (IS_ERR(priv->scu)) {
> > > diff --git a/drivers/gpu/drm/aspeed/aspeed_gfx_out.c
> > > b/drivers/gpu/drm/aspeed/aspeed_gfx_out.c
> > > index 6759cb88415a..5d5e04f15c59 100644
> > > --- a/drivers/gpu/drm/aspeed/aspeed_gfx_out.c
> > > +++ b/drivers/gpu/drm/aspeed/aspeed_gfx_out.c
> > > @@ -10,7 +10,19 @@
> > >
> > > static int aspeed_gfx_get_modes(struct drm_connector *connector) {
> > > - return drm_add_modes_noedid(connector, 800, 600);
> > > + struct aspeed_gfx *priv = container_of(connector, struct
> > aspeed_gfx, connector);
> > > + int mode_count = 0;
> > > +
> > > + switch (priv->flags & CLK_MASK) {
> > > + case CLK_G6:
> > > + mode_count = drm_add_modes_noedid(connector,
> 1024,
> > 768);
> > > + break;
> > > + default:
> > > + mode_count = drm_add_modes_noedid(connector,
> 800,
> > 600);
> > > + break;
> > > + }
> > > +
> > > + return mode_count;
> > > }
> > >
> > > static const struct
> > > --
> > > 2.17.1
> > >
