[PATCH 07/18] media: platform: microchip: Extend gamma table and control range

Balamanikandan Gunasundar
2025-10-09T15:54:41Z

From: Balakrishnan Sambath <balakrishnan.s@microchip.com>

Add support for multiple levels of gamma correction options (1/2.4,
1/2.2, 1/1.8) which can be modified through V4L2 controls(with range
0-2), with a default of 1/2.2(index 1).

Signed-off-by: Balakrishnan Sambath <balakrishnan.s@microchip.com>
Signed-off-by: Balamanikandan Gunasundar <balamanikandan.gunasundar@microchip.com>
---
.../platform/microchip/microchip-isc-base.c | 3 +-
.../microchip/microchip-sama7g5-isc.c | 54 ++++++++++++++-----
2 files changed, 41 insertions(+), 16 deletions(-)

diff --git a/drivers/media/platform/microchip/microchip-isc-base.c b/drivers/media/platform/microchip/microchip-isc-base.c
index 2706a27a2506..cd379f95fc1c 100644
--- a/drivers/media/platform/microchip/microchip-isc-base.c
+++ b/drivers/media/platform/microchip/microchip-isc-base.c
@@ -1715,8 +1715,7 @@ static int isc_ctrl_init(struct isc_device *isc)
ctrls->brightness = 0;

v4l2_ctrl_new_std(hdl, ops, V4L2_CID_BRIGHTNESS, -1024, 1023, 1, 0);
- v4l2_ctrl_new_std(hdl, ops, V4L2_CID_GAMMA, 0, isc->gamma_max, 1,
- isc->gamma_max);
+ v4l2_ctrl_new_std(hdl, ops, V4L2_CID_GAMMA, 0, isc->gamma_max, 1, 1);
isc->awb_ctrl = v4l2_ctrl_new_std(hdl, &isc_awb_ops,
V4L2_CID_AUTO_WHITE_BALANCE,
0, 1, 1, 1);
diff --git a/drivers/media/platform/microchip/microchip-sama7g5-isc.c b/drivers/media/platform/microchip/microchip-sama7g5-isc.c
index 03f7a46acd47..d3ed9cfe6686 100644
--- a/drivers/media/platform/microchip/microchip-sama7g5-isc.c
+++ b/drivers/media/platform/microchip/microchip-sama7g5-isc.c
@@ -320,21 +320,47 @@ static void isc_sama7g5_adapt_pipeline(struct isc_device *isc)
isc->try_config.bits_pipeline &= ISC_SAMA7G5_PIPELINE;
}

-/* Gamma table with gamma 1/2.2 */
+/* Gamma tables with gamma values 0.42, 0.45(Default), 0.56 */
static const u32 isc_sama7g5_gamma_table[][GAMMA_ENTRIES] = {
- /* index 0 --> gamma bipartite */
+ /* index 0 --> gamma bipartite 1/2.4(=0.42) */
{
- 0x980, 0x4c0320, 0x650260, 0x7801e0, 0x8701a0, 0x940180,
- 0xa00160, 0xab0120, 0xb40120, 0xbd0120, 0xc60100, 0xce0100,
- 0xd600e0, 0xdd00e0, 0xe400e0, 0xeb00c0, 0xf100c0, 0xf700c0,
- 0xfd00c0, 0x10300a0, 0x10800c0, 0x10e00a0, 0x11300a0, 0x11800a0,
- 0x11d00a0, 0x12200a0, 0x12700a0, 0x12c0080, 0x13000a0, 0x1350080,
- 0x13900a0, 0x13e0080, 0x1420076, 0x17d0062, 0x1ae0054, 0x1d8004a,
- 0x1fd0044, 0x21f003e, 0x23e003a, 0x25b0036, 0x2760032, 0x28f0030,
- 0x2a7002e, 0x2be002c, 0x2d4002c, 0x2ea0028, 0x2fe0028, 0x3120026,
- 0x3250024, 0x3370024, 0x3490022, 0x35a0022, 0x36b0020, 0x37b0020,
- 0x38b0020, 0x39b001e, 0x3aa001e, 0x3b9001c, 0x3c7001c, 0x3d5001c,
- 0x3e3001c, 0x3f1001c, 0x3ff001a, 0x40c001a },
+ 0x940, 0x4b0310, 0x630250, 0x7601d0, 0x840190, 0x910170,
+ 0x9d0150, 0xa80110, 0xb10110, 0xba0110, 0xc300f0, 0xcb00f0,
+ 0xd300e0, 0xda00e0, 0xe100c0, 0xe800c0, 0xee00c0, 0xf400c0,
+ 0xfa00a0, 0x10000a0, 0x10500a0, 0x10b00a0, 0x11000a0, 0x11500a0,
+ 0x11a0080, 0x11f0080, 0x1240080, 0x1290080, 0x12e0080, 0x1330070,
+ 0x1380070, 0x13c0070, 0x1410070, 0x17a0060, 0x1aa0052, 0x1d40046,
+ 0x1f90042, 0x21b003c, 0x23a0038, 0x2570034, 0x2720030, 0x28b002e,
+ 0x2a3002c, 0x2ba002a, 0x2d0002a, 0x2e60028, 0x2fa0026, 0x30e0026,
+ 0x3210024, 0x3330022, 0x3450022, 0x3560020, 0x3670020, 0x3770020,
+ 0x387001e, 0x396001e, 0x3a5001c, 0x3b3001c, 0x3c1001c, 0x3cf001a,
+ 0x3dd001a, 0x3eb0018, 0x3f90018 },
+ /* index 1 --> gamma bipartite 1/2.2(=0.45) */
+ {
+ 0x980, 0x4c0320, 0x650260, 0x7801e0, 0x8701a0, 0x940180,
+ 0xa00160, 0xab0120, 0xb40120, 0xbd0120, 0xc60100, 0xce0100,
+ 0xd600e0, 0xdd00e0, 0xe400e0, 0xeb00c0, 0xf100c0, 0xf700c0,
+ 0xfd00c0, 0x10300a0, 0x10800c0, 0x10e00a0, 0x11300a0, 0x11800a0,
+ 0x11d00a0, 0x12200a0, 0x12700a0, 0x12c0080, 0x13000a0, 0x1350080,
+ 0x13900a0, 0x13e0080, 0x1420076, 0x17d0062, 0x1ae0054, 0x1d8004a,
+ 0x1fd0044, 0x21f003e, 0x23e003a, 0x25b0036, 0x2760032, 0x28f0030,
+ 0x2a7002e, 0x2be002c, 0x2d4002c, 0x2ea0028, 0x2fe0028, 0x3120026,
+ 0x3250024, 0x3370024, 0x3490022, 0x35a0022, 0x36b0020, 0x37b0020,
+ 0x38b0020, 0x39b001e, 0x3aa001e, 0x3b9001c, 0x3c7001c, 0x3d5001c,
+ 0x3e3001c, 0x3f1001c, 0x3ff001a, 0x40c001a },
+ /* index 2 --> gamma bipartite 1/1.8(=0.56) */
+ {
+ 0xa62, 0x4f0350, 0x680280, 0x7e0200, 0x8d01c0, 0x9a01a0,
+ 0xa50180, 0xb00140, 0xb90140, 0xc20120, 0xcb0120, 0xd30100,
+ 0xdb0100, 0xe300e0, 0xea00e0, 0xf100e0, 0xf700c0, 0xfd00c0,
+ 0x10300c0, 0x10900a0, 0x10e00a0, 0x11400a0, 0x11900a0, 0x11e00a0,
+ 0x12300a0, 0x12800a0, 0x12d0080, 0x1320080, 0x1370080, 0x13c0080,
+ 0x1410080, 0x1460080, 0x14a0070, 0x1830060, 0x1b40052, 0x1df0048,
+ 0x2040042, 0x2250040, 0x2440038, 0x2600036, 0x27b0032, 0x2940030,
+ 0x2ac002e, 0x2c4002c, 0x2da002a, 0x2f0002a, 0x3050028, 0x3190026,
+ 0x32c0026, 0x33e0024, 0x3500024, 0x3610022, 0x3720020, 0x3820020,
+ 0x3920020, 0x3a2001e, 0x3b1001e, 0x3c0001c, 0x3ce001c, 0x3dc001c,
+ 0x3ea001a, 0x3f8001a, 0x4060018, 0x4130018 },
};

static int xisc_parse_dt(struct device *dev, struct isc_device *isc)
@@ -434,7 +460,7 @@ static int microchip_xisc_probe(struct platform_device *pdev)
}

isc->gamma_table = isc_sama7g5_gamma_table;
- isc->gamma_max = 0;
+ isc->gamma_max = 2;

if ((of_machine_is_compatible("microchip,sam9x7"))) {
isc->max_width = ISC_SAM9X7_MAX_SUPPORT_WIDTH;
--
2.34.1