2  * Functions for auto gain.
18 /* auto gain and exposure algorithm based on the knee algorithm described here:
21    Returns 0 if no changes were made, 1 if the gain and or exposure settings
31 	s32 gain, orig_gain, exposure, orig_exposure;  in gspca_expo_autogain()  local
37 	orig_gain = gain = v4l2_ctrl_g_ctrl(gspca_dev->gain);  in gspca_expo_autogain()
49 			if (gain > gain_knee)  in gspca_expo_autogain()
50 				gain--;  in gspca_expo_autogain()
53 			else if (gain > gspca_dev->gain->default_value)  in gspca_expo_autogain()
54 				gain--;  in gspca_expo_autogain()
57 			else if (gain > gspca_dev->gain->minimum)  in gspca_expo_autogain()
58 				gain--;  in gspca_expo_autogain()
62 			if (gain < gspca_dev->gain->default_value)  in gspca_expo_autogain()
63 				gain++;  in gspca_expo_autogain()
66 			else if (gain < gain_knee)  in gspca_expo_autogain()
67 				gain++;  in gspca_expo_autogain()
70 			else if (gain < gspca_dev->gain->maximum)  in gspca_expo_autogain()
71 				gain++;  in gspca_expo_autogain()
77 	if (gain != orig_gain) {  in gspca_expo_autogain()
78 		v4l2_ctrl_s_ctrl(gspca_dev->gain, gain);  in gspca_expo_autogain()
87 		gspca_dbg(gspca_dev, D_FRAM, "autogain: changed gain: %d, expo: %d\n",  in gspca_expo_autogain()
88 			  gain, exposure);  in gspca_expo_autogain()
97    this algorithm normally tries to only adjust the gain (between 40 and
103    Returns 0 if no changes were made, 1 if the gain and or exposure settings
111 	s32 gain_low, gain_high, gain, orig_gain, exposure, orig_exposure;  in gspca_coarse_grained_expo_autogain()  local
117 	orig_gain = gain = v4l2_ctrl_g_ctrl(gspca_dev->gain);  in gspca_coarse_grained_expo_autogain()
120 	gain_low  = (s32)(gspca_dev->gain->maximum - gspca_dev->gain->minimum) /  in gspca_coarse_grained_expo_autogain()
121 		    5 * 2 + gspca_dev->gain->minimum;  in gspca_coarse_grained_expo_autogain()
122 	gain_high = (s32)(gspca_dev->gain->maximum - gspca_dev->gain->minimum) /  in gspca_coarse_grained_expo_autogain()
123 		    5 * 4 + gspca_dev->gain->minimum;  in gspca_coarse_grained_expo_autogain()
132 	if ((gain + steps) > gain_high &&  in gspca_coarse_grained_expo_autogain()
134 		gain = gain_high;  in gspca_coarse_grained_expo_autogain()
137 	} else if ((gain + steps) < gain_low &&  in gspca_coarse_grained_expo_autogain()
139 		gain = gain_low;  in gspca_coarse_grained_expo_autogain()
143 		gain += steps;  in gspca_coarse_grained_expo_autogain()
144 		if (gain > gspca_dev->gain->maximum)  in gspca_coarse_grained_expo_autogain()
145 			gain = gspca_dev->gain->maximum;  in gspca_coarse_grained_expo_autogain()
146 		else if (gain < gspca_dev->gain->minimum)  in gspca_coarse_grained_expo_autogain()
147 			gain = gspca_dev->gain->minimum;  in gspca_coarse_grained_expo_autogain()
160 	if (gain != orig_gain) {  in gspca_coarse_grained_expo_autogain()
161 		v4l2_ctrl_s_ctrl(gspca_dev->gain, gain);  in gspca_coarse_grained_expo_autogain()
170 		gspca_dbg(gspca_dev, D_FRAM, "autogain: changed gain: %d, expo: %d\n",  in gspca_coarse_grained_expo_autogain()
171 			  gain, exposure);  in gspca_coarse_grained_expo_autogain()