[PATCH 2/2] drm/aspeed: Use dt matching for default register values

[Joel Stanley]

On Tue, 2 Feb 2021 at 04:46, Jeremy Kerr <jk at ozlabs.org> wrote:
>
> Hi Joel,
>
> > There are minor differences in the values for the threshold value and
> > the scan line size between families of ASPEED SoC. Additionally the
> > SCU register for the output control differs between families.
> >
> > This adds device tree matching to parameterise these values, allowing
> > us to add support for the AST2400 now, and in the future the AST2600.
>
> Looks good to me. Two super minor things:
>
> > --- a/drivers/gpu/drm/aspeed/aspeed_gfx_crtc.c
> > +++ b/drivers/gpu/drm/aspeed/aspeed_gfx_crtc.c
> > @@ -60,7 +60,8 @@ static void aspeed_gfx_enable_controller(struct
> > aspeed_gfx *priv)
> >         u32 ctrl2 = readl(priv->base + CRT_CTRL2);
> >
> >         /* SCU2C: set DAC source for display output to Graphics CRT (GFX) */
> > -       regmap_update_bits(priv->scu, 0x2c, BIT(16), BIT(16));
> > +       regmap_update_bits(priv->scu, priv->dac_reg, BIT(16), BIT(16));
>
> The comment references SCU2C; but you've implied that this will
> change...
>
> > @@ -228,7 +258,7 @@ static ssize_t dac_mux_store(struct device *dev,
> > struct device_attribute *attr,
> >         if (val > 3)
> >                 return -EINVAL;
> >
> > -       rc = regmap_update_bits(priv->scu, ASPEED_SCU_MISC_CTRL, 0x30000, val << 16);
> > +       rc = regmap_update_bits(priv->scu, priv->dac_reg, 0x30000, val << 16);
> >         if (rc < 0)
> >                 return 0;
> >
> > @@ -241,7 +271,7 @@ static ssize_t dac_mux_show(struct device *dev,
> > struct device_attribute *attr, c
> >         u32 reg;
> >         int rc;
> >
> > -       rc = regmap_read(priv->scu, ASPEED_SCU_MISC_CTRL, &reg);
> > +       rc = regmap_read(priv->scu, priv->dac_reg, &reg);
> >         if (rc)
> >                 return rc;
>
> You've removed the only uses of ASPEED_SCU_MISC_CTRL here, maybe drop
> the #define too?

Good idea. I'll implement both of your suggestions.