static inline u32 compute_dda_inc(fixed20_12 in, unsigned out_int,
bool v, unsigned Bpp)
{
/*
* min(round((prescaled_size_in_pixels - 1) * 0x1000 /
* (post_scaled_size_in_pixels - 1)), MAX)
* Where the value of MAX is as follows:
* For V_DDA_INCREMENT: 15.0 (0xF000)
* For H_DDA_INCREMENT: 4.0 (0x4000) for 4 Bytes/pix formats.
* 8.0 (0x8000) for 2 Bytes/pix formats.
*/
fixed20_12 out = dfixed_init(out_int);
u32 dda_inc;
int max;
if (v) {
max = 15;
} else {
switch (Bpp) {
default:
WARN_ON_ONCE(1);
/* fallthrough */
case 4:
max = 4;
break;
case 2:
max = 8;
break;
}
}
out.full = max_t(u32, out.full - dfixed_const(1), dfixed_const(1));
in.full -= dfixed_const(1);
dda_inc = dfixed_div(in, out);
dda_inc = min_t(u32, dda_inc, dfixed_const(max));
return dda_inc;
}
static int nvsd_set_brightness(struct tegra_dc *dc)
{
u32 bin_width;
int i, j;
int val;
int pix;
int bin_idx;
int incr;
int base;
u32 histo[32];
u32 histo_total = 0; /* count of pixels */
fixed20_12 nonhisto_gain; /* gain of pixels not in histogram */
fixed20_12 est_achieved_gain; /* final gain of pixels */
fixed20_12 histo_gain = dfixed_init(0); /* gain of pixels */
fixed20_12 k, threshold; /* k is the fractional part of HW_K */
fixed20_12 den, num, out;
fixed20_12 pix_avg, pix_avg_softclip;
/* Collet the inputs of the algorithm */
for (i = 0; i < DC_DISP_SD_HISTOGRAM_NUM; i++) {
val = tegra_dc_readl(dc, DC_DISP_SD_HISTOGRAM(i));
for (j = 0; j < 4; j++)
histo[i * 4 + j] = SD_HISTOGRAM_BIN(val, (j * 8));
}
val = tegra_dc_readl(dc, DC_DISP_SD_HW_K_VALUES);
k.full = dfixed_const(SD_HW_K_R(val));
den.full = dfixed_const(1024);
k.full = dfixed_div(k, den);
val = tegra_dc_readl(dc, DC_DISP_SD_SOFT_CLIPPING);
threshold.full = dfixed_const(SD_SOFT_CLIPPING_THRESHOLD(val));
val = tegra_dc_readl(dc, DC_DISP_SD_CONTROL);
bin_width = SD_BIN_WIDTH_VAL(val);
incr = 1 << bin_width;
base = 256 - 32 * incr;
for (pix = base, bin_idx = 0; pix < 256; pix += incr, bin_idx++) {
num.full = dfixed_const(pix + pix + incr);
den.full = dfixed_const(2);
pix_avg.full = dfixed_div(num, den);
pix_avg_softclip.full = nvsd_softclip(pix_avg, k, threshold);
num.full = dfixed_const(histo[bin_idx]);
den.full = dfixed_const(256);
out.full = dfixed_div(num, den);
num.full = dfixed_mul(out, pix_avg_softclip);
out.full = dfixed_div(num, pix_avg);
histo_gain.full += out.full;
histo_total += histo[bin_idx];
}
out.full = dfixed_const(256 - histo_total);
den.full = dfixed_const(1) + k.full;
num.full = dfixed_mul(out, den);
den.full = dfixed_const(256);
nonhisto_gain.full = dfixed_div(num, den);
den.full = nonhisto_gain.full + histo_gain.full;
num.full = dfixed_const(1);
out.full = dfixed_div(num, den);
num.full = dfixed_const(255);
est_achieved_gain.full = dfixed_mul(num, out);
val = dfixed_trunc(est_achieved_gain);
return nvsd_backlght_interplate(val, 128);
}
