summaryrefslogtreecommitdiff
path: root/target/linux/brcm2708/patches-4.4/0339-drm-vc4-Add-support-for-gamma-ramps.patch
blob: af9effe82e8706116fdc0e758c0a65ada38ab31e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
From 6d1609ef815189095a8e44feb38e2c128c3736a5 Mon Sep 17 00:00:00 2001
From: Eric Anholt <eric@anholt.net>
Date: Thu, 31 Mar 2016 18:38:20 -0700
Subject: [PATCH 339/381] drm/vc4: Add support for gamma ramps.

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>
(cherry picked from commit e582b6c7e7f9d0b1e30e8017e4082d3a9ede3310)
---
 drivers/gpu/drm/vc4/vc4_crtc.c | 58 ++++++++++++++++++++++++++++++++++++++++++
 drivers/gpu/drm/vc4/vc4_regs.h |  6 +++++
 2 files changed, 64 insertions(+)

--- a/drivers/gpu/drm/vc4/vc4_crtc.c
+++ b/drivers/gpu/drm/vc4/vc4_crtc.c
@@ -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_
 	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(struc
 
 	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_c
 	.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 = {
@@ -731,6 +782,7 @@ static int vc4_crtc_bind(struct device *
 	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
@@ -771,6 +823,12 @@ static int vc4_crtc_bind(struct device *
 
 	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;
--- a/drivers/gpu/drm/vc4/vc4_regs.h
+++ b/drivers/gpu/drm/vc4/vc4_regs.h
@@ -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