diff options
Diffstat (limited to 'drivers/media/pci/cx88/cx88-dsp.c')
| -rw-r--r-- | drivers/media/pci/cx88/cx88-dsp.c | 50 |
1 files changed, 32 insertions, 18 deletions
diff --git a/drivers/media/pci/cx88/cx88-dsp.c b/drivers/media/pci/cx88/cx88-dsp.c index 235124e2a763..105029088120 100644 --- a/drivers/media/pci/cx88/cx88-dsp.c +++ b/drivers/media/pci/cx88/cx88-dsp.c @@ -31,18 +31,22 @@ #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. */ +/* + * 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 +/* + * 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... */ + * calculate the proper baseband frequencies... + */ #define FREQ_A2M_CARRIER ((s32)(2.114516 * 32768.0)) #define FREQ_A2M_DUAL ((s32)(2.754916 * 32768.0)) @@ -83,8 +87,10 @@ static s32 int_cos(u32 x) 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. */ + /* + * 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; @@ -95,8 +101,10 @@ static s32 int_cos(u32 x) 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 */ + /* + * 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); @@ -115,12 +123,14 @@ static u32 int_goertzel(s16 x[], u32 N, u32 freq) 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. */ + /* + * 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; + return (u32)tmp; } static u32 freq_magnitude(s16 x[], u32 N, u32 freq) @@ -187,7 +197,8 @@ static s32 detect_a2_a2m_eiaj(struct cx88_core *core, s16 x[], u32 N) 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", + dprintk(1, + "detect a2/a2m/eiaj: carrier=%d, stereo=%d, dual=%d, noise=%d\n", carrier, stereo, dual, noise); if (stereo > dual) @@ -201,8 +212,10 @@ static s32 detect_a2_a2m_eiaj(struct cx88_core *core, s16 x[], u32 N) (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 */ + /* + * For EIAJ the carrier is always present, + * so we probably don't need noise detection + */ return ret; } } else { @@ -243,7 +256,8 @@ static s16 *read_rds_samples(struct cx88_core *core, u32 *N) 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", + 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)); @@ -308,9 +322,9 @@ s32 cx88_dsp_detect_stereo_sap(struct cx88_core *core) if (ret != UNSET) 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" : ""); + (ret & V4L2_TUNER_SUB_MONO) ? " mono" : "", + (ret & V4L2_TUNER_SUB_STEREO) ? " stereo" : "", + (ret & V4L2_TUNER_SUB_LANG2) ? " dual" : ""); return ret; } |