ASR_BASE
Change-Id: Icf3719cc0afe3eeb3edc7fa80a2eb5199ca9dda1
diff --git a/marvell/linux/drivers/media/usb/gspca/autogain_functions.c b/marvell/linux/drivers/media/usb/gspca/autogain_functions.c
new file mode 100644
index 0000000..7ae7c43
--- /dev/null
+++ b/marvell/linux/drivers/media/usb/gspca/autogain_functions.c
@@ -0,0 +1,165 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Functions for auto gain.
+ *
+ * Copyright (C) 2010-2012 Hans de Goede <hdegoede@redhat.com>
+ */
+#include "gspca.h"
+
+/* auto gain and exposure algorithm based on the knee algorithm described here:
+ http://ytse.tricolour.net/docs/LowLightOptimization.html
+
+ Returns 0 if no changes were made, 1 if the gain and or exposure settings
+ where changed. */
+int gspca_expo_autogain(
+ struct gspca_dev *gspca_dev,
+ int avg_lum,
+ int desired_avg_lum,
+ int deadzone,
+ int gain_knee,
+ int exposure_knee)
+{
+ s32 gain, orig_gain, exposure, orig_exposure;
+ int i, steps, retval = 0;
+
+ if (v4l2_ctrl_g_ctrl(gspca_dev->autogain) == 0)
+ return 0;
+
+ orig_gain = gain = v4l2_ctrl_g_ctrl(gspca_dev->gain);
+ orig_exposure = exposure = v4l2_ctrl_g_ctrl(gspca_dev->exposure);
+
+ /* If we are of a multiple of deadzone, do multiple steps to reach the
+ desired lumination fast (with the risc of a slight overshoot) */
+ steps = abs(desired_avg_lum - avg_lum) / deadzone;
+
+ gspca_dbg(gspca_dev, D_FRAM, "autogain: lum: %d, desired: %d, steps: %d\n",
+ avg_lum, desired_avg_lum, steps);
+
+ for (i = 0; i < steps; i++) {
+ if (avg_lum > desired_avg_lum) {
+ if (gain > gain_knee)
+ gain--;
+ else if (exposure > exposure_knee)
+ exposure--;
+ else if (gain > gspca_dev->gain->default_value)
+ gain--;
+ else if (exposure > gspca_dev->exposure->minimum)
+ exposure--;
+ else if (gain > gspca_dev->gain->minimum)
+ gain--;
+ else
+ break;
+ } else {
+ if (gain < gspca_dev->gain->default_value)
+ gain++;
+ else if (exposure < exposure_knee)
+ exposure++;
+ else if (gain < gain_knee)
+ gain++;
+ else if (exposure < gspca_dev->exposure->maximum)
+ exposure++;
+ else if (gain < gspca_dev->gain->maximum)
+ gain++;
+ else
+ break;
+ }
+ }
+
+ if (gain != orig_gain) {
+ v4l2_ctrl_s_ctrl(gspca_dev->gain, gain);
+ retval = 1;
+ }
+ if (exposure != orig_exposure) {
+ v4l2_ctrl_s_ctrl(gspca_dev->exposure, exposure);
+ retval = 1;
+ }
+
+ if (retval)
+ gspca_dbg(gspca_dev, D_FRAM, "autogain: changed gain: %d, expo: %d\n",
+ gain, exposure);
+ return retval;
+}
+EXPORT_SYMBOL(gspca_expo_autogain);
+
+/* Autogain + exposure algorithm for cameras with a coarse exposure control
+ (usually this means we can only control the clockdiv to change exposure)
+ As changing the clockdiv so that the fps drops from 30 to 15 fps for
+ example, will lead to a huge exposure change (it effectively doubles),
+ this algorithm normally tries to only adjust the gain (between 40 and
+ 80 %) and if that does not help, only then changes exposure. This leads
+ to a much more stable image then using the knee algorithm which at
+ certain points of the knee graph will only try to adjust exposure,
+ which leads to oscillating as one exposure step is huge.
+
+ Returns 0 if no changes were made, 1 if the gain and or exposure settings
+ where changed. */
+int gspca_coarse_grained_expo_autogain(
+ struct gspca_dev *gspca_dev,
+ int avg_lum,
+ int desired_avg_lum,
+ int deadzone)
+{
+ s32 gain_low, gain_high, gain, orig_gain, exposure, orig_exposure;
+ int steps, retval = 0;
+
+ if (v4l2_ctrl_g_ctrl(gspca_dev->autogain) == 0)
+ return 0;
+
+ orig_gain = gain = v4l2_ctrl_g_ctrl(gspca_dev->gain);
+ orig_exposure = exposure = v4l2_ctrl_g_ctrl(gspca_dev->exposure);
+
+ gain_low = (s32)(gspca_dev->gain->maximum - gspca_dev->gain->minimum) /
+ 5 * 2 + gspca_dev->gain->minimum;
+ gain_high = (s32)(gspca_dev->gain->maximum - gspca_dev->gain->minimum) /
+ 5 * 4 + gspca_dev->gain->minimum;
+
+ /* If we are of a multiple of deadzone, do multiple steps to reach the
+ desired lumination fast (with the risc of a slight overshoot) */
+ steps = (desired_avg_lum - avg_lum) / deadzone;
+
+ gspca_dbg(gspca_dev, D_FRAM, "autogain: lum: %d, desired: %d, steps: %d\n",
+ avg_lum, desired_avg_lum, steps);
+
+ if ((gain + steps) > gain_high &&
+ exposure < gspca_dev->exposure->maximum) {
+ gain = gain_high;
+ gspca_dev->exp_too_low_cnt++;
+ gspca_dev->exp_too_high_cnt = 0;
+ } else if ((gain + steps) < gain_low &&
+ exposure > gspca_dev->exposure->minimum) {
+ gain = gain_low;
+ gspca_dev->exp_too_high_cnt++;
+ gspca_dev->exp_too_low_cnt = 0;
+ } else {
+ gain += steps;
+ if (gain > gspca_dev->gain->maximum)
+ gain = gspca_dev->gain->maximum;
+ else if (gain < gspca_dev->gain->minimum)
+ gain = gspca_dev->gain->minimum;
+ gspca_dev->exp_too_high_cnt = 0;
+ gspca_dev->exp_too_low_cnt = 0;
+ }
+
+ if (gspca_dev->exp_too_high_cnt > 3) {
+ exposure--;
+ gspca_dev->exp_too_high_cnt = 0;
+ } else if (gspca_dev->exp_too_low_cnt > 3) {
+ exposure++;
+ gspca_dev->exp_too_low_cnt = 0;
+ }
+
+ if (gain != orig_gain) {
+ v4l2_ctrl_s_ctrl(gspca_dev->gain, gain);
+ retval = 1;
+ }
+ if (exposure != orig_exposure) {
+ v4l2_ctrl_s_ctrl(gspca_dev->exposure, exposure);
+ retval = 1;
+ }
+
+ if (retval)
+ gspca_dbg(gspca_dev, D_FRAM, "autogain: changed gain: %d, expo: %d\n",
+ gain, exposure);
+ return retval;
+}
+EXPORT_SYMBOL(gspca_coarse_grained_expo_autogain);