media: ccs: Add support for analogue gain coefficient controls

Add four controls for reading CCS analogue gain coefficients. The
values are constants that are device specific.
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/media/i2c/ccs/ccs-core.c

@@ -28,6 +28,7 @@
 #include <linux/v4l2-mediabus.h>
 #include <media/v4l2-fwnode.h>
 #include <media/v4l2-device.h>
+#include <uapi/linux/ccs.h>
 
 #include "ccs.h"
 
@@ -771,14 +772,46 @@ static int ccs_init_controls(struct ccs_sensor *sensor)
 	struct i2c_client *client = v4l2_get_subdevdata(&sensor->src->sd);
 	int rval;
 
-	rval = v4l2_ctrl_handler_init(&sensor->pixel_array->ctrl_handler, 13);
+	rval = v4l2_ctrl_handler_init(&sensor->pixel_array->ctrl_handler, 17);
 	if (rval)
 		return rval;
 
 	sensor->pixel_array->ctrl_handler.lock = &sensor->mutex;
 
 	switch (CCS_LIM(sensor, ANALOG_GAIN_CAPABILITY)) {
-	case CCS_ANALOG_GAIN_CAPABILITY_GLOBAL:
+	case CCS_ANALOG_GAIN_CAPABILITY_GLOBAL: {
+		struct {
+			const char *name;
+			u32 id;
+			s32 value;
+		} const gain_ctrls[] = {
+			{ "Analogue Gain m0", V4L2_CID_CCS_ANALOGUE_GAIN_M0,
+			  CCS_LIM(sensor, ANALOG_GAIN_M0), },
+			{ "Analogue Gain c0", V4L2_CID_CCS_ANALOGUE_GAIN_C0,
+			  CCS_LIM(sensor, ANALOG_GAIN_C0), },
+			{ "Analogue Gain m1", V4L2_CID_CCS_ANALOGUE_GAIN_M1,
+			  CCS_LIM(sensor, ANALOG_GAIN_M1), },
+			{ "Analogue Gain c1", V4L2_CID_CCS_ANALOGUE_GAIN_C1,
+			  CCS_LIM(sensor, ANALOG_GAIN_C1), },
+		};
+		struct v4l2_ctrl_config ctrl_cfg = {
+			.type = V4L2_CTRL_TYPE_INTEGER,
+			.ops = &ccs_ctrl_ops,
+			.flags = V4L2_CTRL_FLAG_READ_ONLY,
+			.step = 1,
+		};
+		unsigned int i;
+
+		for (i = 0; i < ARRAY_SIZE(gain_ctrls); i++) {
+			ctrl_cfg.name = gain_ctrls[i].name;
+			ctrl_cfg.id = gain_ctrls[i].id;
+			ctrl_cfg.min = ctrl_cfg.max = ctrl_cfg.def =
+				gain_ctrls[i].value;
+
+			v4l2_ctrl_new_custom(&sensor->pixel_array->ctrl_handler,
+					     &ctrl_cfg, NULL);
+		}
+
 		v4l2_ctrl_new_std(&sensor->pixel_array->ctrl_handler,
 				  &ccs_ctrl_ops, V4L2_CID_ANALOGUE_GAIN,
 				  CCS_LIM(sensor, ANALOG_GAIN_CODE_MIN),
@@ -787,6 +820,7 @@ static int ccs_init_controls(struct ccs_sensor *sensor)
 				      1U),
 				  CCS_LIM(sensor, ANALOG_GAIN_CODE_MIN));
 	}
+	}
 
 	if (CCS_LIM(sensor, DIGITAL_GAIN_CAPABILITY) ==
 	    CCS_DIGITAL_GAIN_CAPABILITY_GLOBAL ||