RE: [PATCH v1 2/2] drm/aspeed: Add 1024x768 mode for AST2600

From: Tommy Huang
Date: Tue Apr 26 2022 - 04:37:07 EST




> -----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
> >