[RFC PATCH] drm/sun4i: Implement gamma correction
Vasily Khoruzhick
anarsoul at gmail.com
Thu Mar 14 17:54:26 UTC 2019
On Thu, Mar 14, 2019 at 8:42 AM Maxime Ripard <maxime.ripard at bootlin.com> wrote:
>
> Hi Vasily,
>
> On Wed, Mar 13, 2019 at 07:58:38PM -0700, Vasily Khoruzhick wrote:
> > Add support for gamma corretion to sun4i TCON driver. Its LUT has 256
> > entries and can be updated only when gamma correction is disabled.
> >
> > Signed-off-by: Vasily Khoruzhick <anarsoul at gmail.com>
>
> It's not really clear to me what you expect a comment on?
I'm not sure that I put gamma correction into right place - gamma lut
seems to be a property of CRTC, but registers are in TCON module.
Also I'm not sure if gamma correction is supported across all
Allwinner SoCs - if it doesn't, how do we handle this?
>
> Maxime
>
> > ---
> > drivers/gpu/drm/sun4i/sun4i_crtc.c | 15 ++++++++++++++
> > drivers/gpu/drm/sun4i/sun4i_tcon.c | 33 ++++++++++++++++++++++++++++++
> > drivers/gpu/drm/sun4i/sun4i_tcon.h | 12 ++++++++++-
> > 3 files changed, 59 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/sun4i/sun4i_crtc.c b/drivers/gpu/drm/sun4i/sun4i_crtc.c
> > index 3eedf335a935..719259d09632 100644
> > --- a/drivers/gpu/drm/sun4i/sun4i_crtc.c
> > +++ b/drivers/gpu/drm/sun4i/sun4i_crtc.c
> > @@ -101,6 +101,20 @@ static void sun4i_crtc_atomic_flush(struct drm_crtc *crtc,
> > drm_crtc_send_vblank_event(crtc, event);
> > spin_unlock_irq(&crtc->dev->event_lock);
> > }
> > +
> > + if (crtc->state->color_mgmt_changed) {
> > + if (crtc->state->gamma_lut) {
> > + /* LUT can be only updated when gamma correction is
> > + * disabled
> > + */
> > + sun4i_tcon_enable_gamma(scrtc->tcon, false);
> > + sun4i_tcon_load_gamma_lut(scrtc->tcon,
> > + crtc->state->gamma_lut->data);
> > + sun4i_tcon_enable_gamma(scrtc->tcon, true);
> > + } else
> > + sun4i_tcon_enable_gamma(scrtc->tcon, false);
> > + }
> > +
> > }
> >
> > static void sun4i_crtc_atomic_disable(struct drm_crtc *crtc,
> > @@ -184,6 +198,7 @@ static const struct drm_crtc_funcs sun4i_crtc_funcs = {
> > .set_config = drm_atomic_helper_set_config,
> > .enable_vblank = sun4i_crtc_enable_vblank,
> > .disable_vblank = sun4i_crtc_disable_vblank,
> > + .gamma_set = drm_atomic_helper_legacy_gamma_set,
> > };
> >
> > struct sun4i_crtc *sun4i_crtc_init(struct drm_device *drm,
> > diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.c b/drivers/gpu/drm/sun4i/sun4i_tcon.c
> > index cf45d0f940f9..3f5f9d4f54a6 100644
> > --- a/drivers/gpu/drm/sun4i/sun4i_tcon.c
> > +++ b/drivers/gpu/drm/sun4i/sun4i_tcon.c
> > @@ -215,6 +215,34 @@ void sun4i_tcon_enable_vblank(struct sun4i_tcon *tcon, bool enable)
> > }
> > EXPORT_SYMBOL(sun4i_tcon_enable_vblank);
> >
> > +void sun4i_tcon_load_gamma_lut(struct sun4i_tcon *tcon,
> > + struct drm_color_lut *lut)
> > +{
> > + int i;
> > +
> > + for (i = 0; i < SUN4I_TCON_GAMMA_LUT_SIZE; i++) {
> > + u32 r, g, b;
> > +
> > + r = drm_color_lut_extract(lut[i].red, 8);
> > + g = drm_color_lut_extract(lut[i].green, 8);
> > + b = drm_color_lut_extract(lut[i].blue, 8);
> > +
> > + regmap_write(tcon->regs, SUN4I_TCON_GAMMA_TABLE_REG + 4 * i,
> > + SUN4I_TCON_GAMMA_TABLE_R(r) |
> > + SUN4I_TCON_GAMMA_TABLE_G(g) |
> > + SUN4I_TCON_GAMMA_TABLE_B(b));
> > + }
> > +}
> > +EXPORT_SYMBOL(sun4i_tcon_load_gamma_lut);
> > +
> > +void sun4i_tcon_enable_gamma(struct sun4i_tcon *tcon, bool enable)
> > +{
> > + regmap_update_bits(tcon->regs, SUN4I_TCON_GCTL_REG,
> > + SUN4I_TCON_GCTL_GAMMA_ENABLE,
> > + enable ? SUN4I_TCON_GCTL_GAMMA_ENABLE : 0);
> > +}
> > +EXPORT_SYMBOL(sun4i_tcon_enable_gamma);
> > +
> > /*
> > * This function is a helper for TCON output muxing. The TCON output
> > * muxing control register in earlier SoCs (without the TCON TOP block)
> > @@ -1261,6 +1289,11 @@ static int sun4i_tcon_bind(struct device *dev, struct device *master,
> >
> > list_add_tail(&tcon->list, &drv->tcon_list);
> >
> > + drm_mode_crtc_set_gamma_size(&tcon->crtc->crtc,
> > + SUN4I_TCON_GAMMA_LUT_SIZE);
> > + drm_crtc_enable_color_mgmt(&tcon->crtc->crtc, 0, false,
> > + tcon->crtc->crtc.gamma_size);
> > +
> > return 0;
> >
> > err_free_dotclock:
> > diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.h b/drivers/gpu/drm/sun4i/sun4i_tcon.h
> > index 84cfb1952ff7..68a29e49e426 100644
> > --- a/drivers/gpu/drm/sun4i/sun4i_tcon.h
> > +++ b/drivers/gpu/drm/sun4i/sun4i_tcon.h
> > @@ -22,6 +22,7 @@
> >
> > #define SUN4I_TCON_GCTL_REG 0x0
> > #define SUN4I_TCON_GCTL_TCON_ENABLE BIT(31)
> > +#define SUN4I_TCON_GCTL_GAMMA_ENABLE BIT(30)
> > #define SUN4I_TCON_GCTL_IOMAP_MASK BIT(0)
> > #define SUN4I_TCON_GCTL_IOMAP_TCON1 (1 << 0)
> > #define SUN4I_TCON_GCTL_IOMAP_TCON0 (0 << 0)
> > @@ -215,7 +216,13 @@
> > #define SUN4I_TCON1_FILL_BEG2_REG 0x31c
> > #define SUN4I_TCON1_FILL_END2_REG 0x320
> > #define SUN4I_TCON1_FILL_DATA2_REG 0x324
> > -#define SUN4I_TCON1_GAMMA_TABLE_REG 0x400
> > +
> > +#define SUN4I_TCON_GAMMA_TABLE_REG 0x400
> > +#define SUN4I_TCON_GAMMA_TABLE_B(x) ((x) & 0xff)
> > +#define SUN4I_TCON_GAMMA_TABLE_G(x) (((x) & 0xff) << 8)
> > +#define SUN4I_TCON_GAMMA_TABLE_R(x) (((x) & 0xff) << 16)
> > +
> > +#define SUN4I_TCON_GAMMA_LUT_SIZE 256
> >
> > #define SUN4I_TCON_MAX_CHANNELS 2
> >
> > @@ -278,6 +285,9 @@ void sun4i_tcon_mode_set(struct sun4i_tcon *tcon,
> > const struct drm_display_mode *mode);
> > void sun4i_tcon_set_status(struct sun4i_tcon *crtc,
> > const struct drm_encoder *encoder, bool enable);
> > +void sun4i_tcon_load_gamma_lut(struct sun4i_tcon *tcon,
> > + struct drm_color_lut *lut);
> > +void sun4i_tcon_enable_gamma(struct sun4i_tcon *tcon, bool enable);
> >
> > extern const struct of_device_id sun4i_tcon_of_table[];
> >
> > --
> > 2.21.0
> >
>
> --
> Maxime Ripard, Bootlin
> Embedded Linux and Kernel engineering
> https://bootlin.com
> -----BEGIN PGP SIGNATURE-----
>
> iHUEABYIAB0WIQRcEzekXsqa64kGDp7j7w1vZxhRxQUCXIp2SwAKCRDj7w1vZxhR
> xSnbAP9ZiYBt1fgCp+KW1N+OWLfacqrrgWPEWsI4Mqlhstt55AD9FXYVo74SWFUO
> pq01CNG+Ci/cAN7u77wT3jaxgL7qvQc=
> =TuHd
> -----END PGP SIGNATURE-----
More information about the dri-devel
mailing list