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

From: Joel Stanley
Date: Tue Apr 26 2022 - 03:48:14 EST

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?

> +#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
>