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drm/vc4: Add support for gamma ramps.

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We could possibly save a bit of power by not requesting gamma
conversion when the ramp happens to be 1:1, but at least if all the
CRTCs are off the SRAM will be disabled.

This should fix brightness sliders in a lot of fullscreen games.

Signed-off-by: Eric Anholt <eric@anholt.net>
This commit is contained in:
Eric Anholt 2016-03-31 18:38:20 -07:00
parent 5883980313
commit e582b6c7e7
2 changed files with 64 additions and 0 deletions
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58
drivers/gpu/drm/vc4/vc4_crtc.c
View file

@ -49,6 +49,10 @@ struct vc4_crtc {
/* Which HVS channel we're using for our CRTC. */
int channel;
u8 lut_r[256];
u8 lut_g[256];
u8 lut_b[256];
struct drm_pending_vblank_event *event;
};
@ -147,6 +151,46 @@ static void vc4_crtc_destroy(struct drm_crtc *crtc)
drm_crtc_cleanup(crtc);
}
static void
vc4_crtc_lut_load(struct drm_crtc *crtc)
{
struct drm_device *dev = crtc->dev;
struct vc4_dev *vc4 = to_vc4_dev(dev);
struct vc4_crtc *vc4_crtc = to_vc4_crtc(crtc);
u32 i;
/* The LUT memory is laid out with each HVS channel in order,
* each of which takes 256 writes for R, 256 for G, then 256
* for B.
*/
HVS_WRITE(SCALER_GAMADDR,
SCALER_GAMADDR_AUTOINC |
(vc4_crtc->channel * 3 * crtc->gamma_size));
for (i = 0; i < crtc->gamma_size; i++)
HVS_WRITE(SCALER_GAMDATA, vc4_crtc->lut_r[i]);
for (i = 0; i < crtc->gamma_size; i++)
HVS_WRITE(SCALER_GAMDATA, vc4_crtc->lut_g[i]);
for (i = 0; i < crtc->gamma_size; i++)
HVS_WRITE(SCALER_GAMDATA, vc4_crtc->lut_b[i]);
}
static void
vc4_crtc_gamma_set(struct drm_crtc *crtc, u16 *r, u16 *g, u16 *b,
uint32_t start, uint32_t size)
{
struct vc4_crtc *vc4_crtc = to_vc4_crtc(crtc);
u32 i;
for (i = start; i < start + size; i++) {
vc4_crtc->lut_r[i] = r[i] >> 8;
vc4_crtc->lut_g[i] = g[i] >> 8;
vc4_crtc->lut_b[i] = b[i] >> 8;
}
vc4_crtc_lut_load(crtc);
}
static u32 vc4_get_fifo_full_level(u32 format)
{
static const u32 fifo_len_bytes = 64;
@ -260,8 +304,14 @@ static void vc4_crtc_mode_set_nofb(struct drm_crtc *crtc)
HVS_WRITE(SCALER_DISPBKGNDX(vc4_crtc->channel),
SCALER_DISPBKGND_AUTOHS |
SCALER_DISPBKGND_GAMMA |
(interlace ? SCALER_DISPBKGND_INTERLACE : 0));
/* Reload the LUT, since the SRAMs would have been disabled if
* all CRTCs had SCALER_DISPBKGND_GAMMA unset at once.
*/
vc4_crtc_lut_load(crtc);
if (debug_dump_regs) {
DRM_INFO("CRTC %d regs after:\n", drm_crtc_index(crtc));
vc4_crtc_dump_regs(vc4_crtc);
@ -613,6 +663,7 @@ static const struct drm_crtc_funcs vc4_crtc_funcs = {
.reset = drm_atomic_helper_crtc_reset,
.atomic_duplicate_state = vc4_crtc_duplicate_state,
.atomic_destroy_state = vc4_crtc_destroy_state,
.gamma_set = vc4_crtc_gamma_set,
};
static const struct drm_crtc_helper_funcs vc4_crtc_helper_funcs = {
@ -711,6 +762,7 @@ static int vc4_crtc_bind(struct device *dev, struct device *master, void *data)
primary_plane->crtc = crtc;
vc4->crtc[drm_crtc_index(crtc)] = vc4_crtc;
vc4_crtc->channel = vc4_crtc->data->hvs_channel;
drm_mode_crtc_set_gamma_size(crtc, ARRAY_SIZE(vc4_crtc->lut_r));
/* Set up some arbitrary number of planes. We're not limited
* by a set number of physical registers, just the space in
@ -751,6 +803,12 @@ static int vc4_crtc_bind(struct device *dev, struct device *master, void *data)
vc4_set_crtc_possible_masks(drm, crtc);
for (i = 0; i < crtc->gamma_size; i++) {
vc4_crtc->lut_r[i] = i;
vc4_crtc->lut_g[i] = i;
vc4_crtc->lut_b[i] = i;
}
platform_set_drvdata(pdev, vc4_crtc);
return 0;

6
drivers/gpu/drm/vc4/vc4_regs.h
View file

@ -390,6 +390,12 @@
#define SCALER_DISPBASE2 0x0000006c
#define SCALER_DISPALPHA2 0x00000070
#define SCALER_GAMADDR 0x00000078
# define SCALER_GAMADDR_AUTOINC BIT(31)
/* Enables all gamma ramp SRAMs, not just those of CRTCs with gamma
* enabled.
*/
# define SCALER_GAMADDR_SRAMENB BIT(30)
#define SCALER_GAMDATA 0x000000e0
#define SCALER_DLIST_START 0x00002000
#define SCALER_DLIST_SIZE 0x00004000