diff options
Diffstat (limited to 'drivers/media/video/cx88/cx88-dsp.c')
| -rw-r--r-- | drivers/media/video/cx88/cx88-dsp.c | 322 |
1 files changed, 0 insertions, 322 deletions
diff --git a/drivers/media/video/cx88/cx88-dsp.c b/drivers/media/video/cx88/cx88-dsp.c deleted file mode 100644 index a9907265ff66..000000000000 --- a/drivers/media/video/cx88/cx88-dsp.c +++ /dev/null @@ -1,322 +0,0 @@ -/* - * - * Stereo and SAP detection for cx88 - * - * Copyright (c) 2009 Marton Balint <cus@fazekas.hu> - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. - */ - -#include <linux/slab.h> -#include <linux/kernel.h> -#include <linux/module.h> -#include <linux/jiffies.h> -#include <asm/div64.h> - -#include "cx88.h" -#include "cx88-reg.h" - -#define INT_PI ((s32)(3.141592653589 * 32768.0)) - -#define compat_remainder(a, b) \ - ((float)(((s32)((a)*100))%((s32)((b)*100)))/100.0) - -#define baseband_freq(carrier, srate, tone) ((s32)( \ - (compat_remainder(carrier + tone, srate)) / srate * 2 * INT_PI)) - -/* We calculate the baseband frequencies of the carrier and the pilot tones - * based on the the sampling rate of the audio rds fifo. */ - -#define FREQ_A2_CARRIER baseband_freq(54687.5, 2689.36, 0.0) -#define FREQ_A2_DUAL baseband_freq(54687.5, 2689.36, 274.1) -#define FREQ_A2_STEREO baseband_freq(54687.5, 2689.36, 117.5) - -/* The frequencies below are from the reference driver. They probably need - * further adjustments, because they are not tested at all. You may even need - * to play a bit with the registers of the chip to select the proper signal - * for the input of the audio rds fifo, and measure it's sampling rate to - * calculate the proper baseband frequencies... */ - -#define FREQ_A2M_CARRIER ((s32)(2.114516 * 32768.0)) -#define FREQ_A2M_DUAL ((s32)(2.754916 * 32768.0)) -#define FREQ_A2M_STEREO ((s32)(2.462326 * 32768.0)) - -#define FREQ_EIAJ_CARRIER ((s32)(1.963495 * 32768.0)) /* 5pi/8 */ -#define FREQ_EIAJ_DUAL ((s32)(2.562118 * 32768.0)) -#define FREQ_EIAJ_STEREO ((s32)(2.601053 * 32768.0)) - -#define FREQ_BTSC_DUAL ((s32)(1.963495 * 32768.0)) /* 5pi/8 */ -#define FREQ_BTSC_DUAL_REF ((s32)(1.374446 * 32768.0)) /* 7pi/16 */ - -#define FREQ_BTSC_SAP ((s32)(2.471532 * 32768.0)) -#define FREQ_BTSC_SAP_REF ((s32)(1.730072 * 32768.0)) - -/* The spectrum of the signal should be empty between these frequencies. */ -#define FREQ_NOISE_START ((s32)(0.100000 * 32768.0)) -#define FREQ_NOISE_END ((s32)(1.200000 * 32768.0)) - -static unsigned int dsp_debug; -module_param(dsp_debug, int, 0644); -MODULE_PARM_DESC(dsp_debug, "enable audio dsp debug messages"); - -#define dprintk(level, fmt, arg...) if (dsp_debug >= level) \ - printk(KERN_DEBUG "%s/0: " fmt, core->name , ## arg) - -static s32 int_cos(u32 x) -{ - u32 t2, t4, t6, t8; - s32 ret; - u16 period = x / INT_PI; - if (period % 2) - return -int_cos(x - INT_PI); - x = x % INT_PI; - if (x > INT_PI/2) - return -int_cos(INT_PI/2 - (x % (INT_PI/2))); - /* Now x is between 0 and INT_PI/2. - * To calculate cos(x) we use it's Taylor polinom. */ - t2 = x*x/32768/2; - t4 = t2*x/32768*x/32768/3/4; - t6 = t4*x/32768*x/32768/5/6; - t8 = t6*x/32768*x/32768/7/8; - ret = 32768-t2+t4-t6+t8; - return ret; -} - -static u32 int_goertzel(s16 x[], u32 N, u32 freq) -{ - /* We use the Goertzel algorithm to determine the power of the - * given frequency in the signal */ - s32 s_prev = 0; - s32 s_prev2 = 0; - s32 coeff = 2*int_cos(freq); - u32 i; - - u64 tmp; - u32 divisor; - - for (i = 0; i < N; i++) { - s32 s = x[i] + ((s64)coeff*s_prev/32768) - s_prev2; - s_prev2 = s_prev; - s_prev = s; - } - - tmp = (s64)s_prev2 * s_prev2 + (s64)s_prev * s_prev - - (s64)coeff * s_prev2 * s_prev / 32768; - - /* XXX: N must be low enough so that N*N fits in s32. - * Else we need two divisions. */ - divisor = N * N; - do_div(tmp, divisor); - - return (u32) tmp; -} - -static u32 freq_magnitude(s16 x[], u32 N, u32 freq) -{ - u32 sum = int_goertzel(x, N, freq); - return (u32)int_sqrt(sum); -} - -static u32 noise_magnitude(s16 x[], u32 N, u32 freq_start, u32 freq_end) -{ - int i; - u32 sum = 0; - u32 freq_step; - int samples = 5; - - if (N > 192) { - /* The last 192 samples are enough for noise detection */ - x += (N-192); - N = 192; - } - - freq_step = (freq_end - freq_start) / (samples - 1); - - for (i = 0; i < samples; i++) { - sum += int_goertzel(x, N, freq_start); - freq_start += freq_step; - } - - return (u32)int_sqrt(sum / samples); -} - -static s32 detect_a2_a2m_eiaj(struct cx88_core *core, s16 x[], u32 N) -{ - s32 carrier, stereo, dual, noise; - s32 carrier_freq, stereo_freq, dual_freq; - s32 ret; - - switch (core->tvaudio) { - case WW_BG: - case WW_DK: - carrier_freq = FREQ_A2_CARRIER; - stereo_freq = FREQ_A2_STEREO; - dual_freq = FREQ_A2_DUAL; - break; - case WW_M: - carrier_freq = FREQ_A2M_CARRIER; - stereo_freq = FREQ_A2M_STEREO; - dual_freq = FREQ_A2M_DUAL; - break; - case WW_EIAJ: - carrier_freq = FREQ_EIAJ_CARRIER; - stereo_freq = FREQ_EIAJ_STEREO; - dual_freq = FREQ_EIAJ_DUAL; - break; - default: - printk(KERN_WARNING "%s/0: unsupported audio mode %d for %s\n", - core->name, core->tvaudio, __func__); - return UNSET; - } - - carrier = freq_magnitude(x, N, carrier_freq); - stereo = freq_magnitude(x, N, stereo_freq); - dual = freq_magnitude(x, N, dual_freq); - noise = noise_magnitude(x, N, FREQ_NOISE_START, FREQ_NOISE_END); - - dprintk(1, "detect a2/a2m/eiaj: carrier=%d, stereo=%d, dual=%d, " - "noise=%d\n", carrier, stereo, dual, noise); - - if (stereo > dual) - ret = V4L2_TUNER_SUB_STEREO; - else - ret = V4L2_TUNER_SUB_LANG1 | V4L2_TUNER_SUB_LANG2; - - if (core->tvaudio == WW_EIAJ) { - /* EIAJ checks may need adjustments */ - if ((carrier > max(stereo, dual)*2) && - (carrier < max(stereo, dual)*6) && - (carrier > 20 && carrier < 200) && - (max(stereo, dual) > min(stereo, dual))) { - /* For EIAJ the carrier is always present, - so we probably don't need noise detection */ - return ret; - } - } else { - if ((carrier > max(stereo, dual)*2) && - (carrier < max(stereo, dual)*8) && - (carrier > 20 && carrier < 200) && - (noise < 10) && - (max(stereo, dual) > min(stereo, dual)*2)) { - return ret; - } - } - return V4L2_TUNER_SUB_MONO; -} - -static s32 detect_btsc(struct cx88_core *core, s16 x[], u32 N) -{ - s32 sap_ref = freq_magnitude(x, N, FREQ_BTSC_SAP_REF); - s32 sap = freq_magnitude(x, N, FREQ_BTSC_SAP); - s32 dual_ref = freq_magnitude(x, N, FREQ_BTSC_DUAL_REF); - s32 dual = freq_magnitude(x, N, FREQ_BTSC_DUAL); - dprintk(1, "detect btsc: dual_ref=%d, dual=%d, sap_ref=%d, sap=%d" - "\n", dual_ref, dual, sap_ref, sap); - /* FIXME: Currently not supported */ - return UNSET; -} - -static s16 *read_rds_samples(struct cx88_core *core, u32 *N) -{ - const struct sram_channel *srch = &cx88_sram_channels[SRAM_CH27]; - s16 *samples; - - unsigned int i; - unsigned int bpl = srch->fifo_size/AUD_RDS_LINES; - unsigned int spl = bpl/4; - unsigned int sample_count = spl*(AUD_RDS_LINES-1); - - u32 current_address = cx_read(srch->ptr1_reg); - u32 offset = (current_address - srch->fifo_start + bpl); - - dprintk(1, "read RDS samples: current_address=%08x (offset=%08x), " - "sample_count=%d, aud_intstat=%08x\n", current_address, - current_address - srch->fifo_start, sample_count, - cx_read(MO_AUD_INTSTAT)); - - samples = kmalloc(sizeof(s16)*sample_count, GFP_KERNEL); - if (!samples) - return NULL; - - *N = sample_count; - - for (i = 0; i < sample_count; i++) { - offset = offset % (AUD_RDS_LINES*bpl); - samples[i] = cx_read(srch->fifo_start + offset); - offset += 4; - } - - if (dsp_debug >= 2) { - dprintk(2, "RDS samples dump: "); - for (i = 0; i < sample_count; i++) - printk("%hd ", samples[i]); - printk(".\n"); - } - - return samples; -} - -s32 cx88_dsp_detect_stereo_sap(struct cx88_core *core) -{ - s16 *samples; - u32 N = 0; - s32 ret = UNSET; - - /* If audio RDS fifo is disabled, we can't read the samples */ - if (!(cx_read(MO_AUD_DMACNTRL) & 0x04)) - return ret; - if (!(cx_read(AUD_CTL) & EN_FMRADIO_EN_RDS)) - return ret; - - /* Wait at least 500 ms after an audio standard change */ - if (time_before(jiffies, core->last_change + msecs_to_jiffies(500))) - return ret; - - samples = read_rds_samples(core, &N); - - if (!samples) - return ret; - - switch (core->tvaudio) { - case WW_BG: - case WW_DK: - case WW_EIAJ: - case WW_M: - ret = detect_a2_a2m_eiaj(core, samples, N); - break; - case WW_BTSC: - ret = detect_btsc(core, samples, N); - break; - case WW_NONE: - case WW_I: - case WW_L: - case WW_I2SPT: - case WW_FM: - case WW_I2SADC: - break; - } - - kfree(samples); - - if (UNSET != ret) - dprintk(1, "stereo/sap detection result:%s%s%s\n", - (ret & V4L2_TUNER_SUB_MONO) ? " mono" : "", - (ret & V4L2_TUNER_SUB_STEREO) ? " stereo" : "", - (ret & V4L2_TUNER_SUB_LANG2) ? " dual" : ""); - - return ret; -} -EXPORT_SYMBOL(cx88_dsp_detect_stereo_sap); - |