3  * Functions for auto gain.
9 /* auto gain and exposure algorithm based on the knee algorithm described here:
12    Returns 0 if no changes were made, 1 if the gain and or exposure settings
22 	s32 gain, orig_gain, exposure, orig_exposure;  in gspca_expo_autogain()  local
28 	orig_gain = gain = v4l2_ctrl_g_ctrl(gspca_dev->gain);  in gspca_expo_autogain()
40 			if (gain > gain_knee)  in gspca_expo_autogain()
41 				gain--;  in gspca_expo_autogain()
44 			else if (gain > gspca_dev->gain->default_value)  in gspca_expo_autogain()
45 				gain--;  in gspca_expo_autogain()
48 			else if (gain > gspca_dev->gain->minimum)  in gspca_expo_autogain()
49 				gain--;  in gspca_expo_autogain()
53 			if (gain < gspca_dev->gain->default_value)  in gspca_expo_autogain()
54 				gain++;  in gspca_expo_autogain()
57 			else if (gain < gain_knee)  in gspca_expo_autogain()
58 				gain++;  in gspca_expo_autogain()
61 			else if (gain < gspca_dev->gain->maximum)  in gspca_expo_autogain()
62 				gain++;  in gspca_expo_autogain()
68 	if (gain != orig_gain) {  in gspca_expo_autogain()
69 		v4l2_ctrl_s_ctrl(gspca_dev->gain, gain);  in gspca_expo_autogain()
78 		gspca_dbg(gspca_dev, D_FRAM, "autogain: changed gain: %d, expo: %d\n",  in gspca_expo_autogain()
79 			  gain, exposure);  in gspca_expo_autogain()
88    this algorithm normally tries to only adjust the gain (between 40 and
94    Returns 0 if no changes were made, 1 if the gain and or exposure settings
102 	s32 gain_low, gain_high, gain, orig_gain, exposure, orig_exposure;  in gspca_coarse_grained_expo_autogain()  local
108 	orig_gain = gain = v4l2_ctrl_g_ctrl(gspca_dev->gain);  in gspca_coarse_grained_expo_autogain()
111 	gain_low  = (s32)(gspca_dev->gain->maximum - gspca_dev->gain->minimum) /  in gspca_coarse_grained_expo_autogain()
112 		    5 * 2 + gspca_dev->gain->minimum;  in gspca_coarse_grained_expo_autogain()
113 	gain_high = (s32)(gspca_dev->gain->maximum - gspca_dev->gain->minimum) /  in gspca_coarse_grained_expo_autogain()
114 		    5 * 4 + gspca_dev->gain->minimum;  in gspca_coarse_grained_expo_autogain()
123 	if ((gain + steps) > gain_high &&  in gspca_coarse_grained_expo_autogain()
125 		gain = gain_high;  in gspca_coarse_grained_expo_autogain()
128 	} else if ((gain + steps) < gain_low &&  in gspca_coarse_grained_expo_autogain()
130 		gain = gain_low;  in gspca_coarse_grained_expo_autogain()
134 		gain += steps;  in gspca_coarse_grained_expo_autogain()
135 		if (gain > gspca_dev->gain->maximum)  in gspca_coarse_grained_expo_autogain()
136 			gain = gspca_dev->gain->maximum;  in gspca_coarse_grained_expo_autogain()
137 		else if (gain < gspca_dev->gain->minimum)  in gspca_coarse_grained_expo_autogain()
138 			gain = gspca_dev->gain->minimum;  in gspca_coarse_grained_expo_autogain()
151 	if (gain != orig_gain) {  in gspca_coarse_grained_expo_autogain()
152 		v4l2_ctrl_s_ctrl(gspca_dev->gain, gain);  in gspca_coarse_grained_expo_autogain()
161 		gspca_dbg(gspca_dev, D_FRAM, "autogain: changed gain: %d, expo: %d\n",  in gspca_coarse_grained_expo_autogain()
162 			  gain, exposure);  in gspca_coarse_grained_expo_autogain()