diff options
Diffstat (limited to 'drivers/media/platform/vivid/vivid-sdr-cap.c')
| -rw-r--r-- | drivers/media/platform/vivid/vivid-sdr-cap.c | 66 |
1 files changed, 27 insertions, 39 deletions
diff --git a/drivers/media/platform/vivid/vivid-sdr-cap.c b/drivers/media/platform/vivid/vivid-sdr-cap.c index 4af55f18829f..caf131666e37 100644 --- a/drivers/media/platform/vivid/vivid-sdr-cap.c +++ b/drivers/media/platform/vivid/vivid-sdr-cap.c @@ -27,6 +27,7 @@ #include <media/v4l2-common.h> #include <media/v4l2-event.h> #include <media/v4l2-dv-timings.h> +#include <linux/fixp-arith.h> #include "vivid-core.h" #include "vivid-ctrls.h" @@ -423,40 +424,19 @@ int vidioc_g_fmt_sdr_cap(struct file *file, void *fh, struct v4l2_format *f) return 0; } -#define FIXP_FRAC (1 << 15) -#define FIXP_PI ((int)(FIXP_FRAC * 3.141592653589)) - -/* cos() from cx88 driver: cx88-dsp.c */ -static s32 fixp_cos(unsigned int x) -{ - u32 t2, t4, t6, t8; - u16 period = x / FIXP_PI; - - if (period % 2) - return -fixp_cos(x - FIXP_PI); - x = x % FIXP_PI; - if (x > FIXP_PI/2) - return -fixp_cos(FIXP_PI/2 - (x % (FIXP_PI/2))); - /* Now x is between 0 and FIXP_PI/2. - * To calculate cos(x) we use it's Taylor polinom. */ - t2 = x*x/FIXP_FRAC/2; - t4 = t2*x/FIXP_FRAC*x/FIXP_FRAC/3/4; - t6 = t4*x/FIXP_FRAC*x/FIXP_FRAC/5/6; - t8 = t6*x/FIXP_FRAC*x/FIXP_FRAC/7/8; - return FIXP_FRAC-t2+t4-t6+t8; -} - -static inline s32 fixp_sin(unsigned int x) -{ - return -fixp_cos(x + (FIXP_PI / 2)); -} +#define FIXP_N (15) +#define FIXP_FRAC (1 << FIXP_N) +#define FIXP_2PI ((int)(2 * 3.141592653589 * FIXP_FRAC)) void vivid_sdr_cap_process(struct vivid_dev *dev, struct vivid_buffer *buf) { u8 *vbuf = vb2_plane_vaddr(&buf->vb, 0); unsigned long i; unsigned long plane_size = vb2_plane_size(&buf->vb, 0); - int fixp_src_phase_step, fixp_i, fixp_q; + s32 src_phase_step; + s32 mod_phase_step; + s32 fixp_i; + s32 fixp_q; /* * TODO: Generated beep tone goes very crackly when sample rate is @@ -466,28 +446,36 @@ void vivid_sdr_cap_process(struct vivid_dev *dev, struct vivid_buffer *buf) /* calculate phase step */ #define BEEP_FREQ 1000 /* 1kHz beep */ - fixp_src_phase_step = DIV_ROUND_CLOSEST(2 * FIXP_PI * BEEP_FREQ, + src_phase_step = DIV_ROUND_CLOSEST(FIXP_2PI * BEEP_FREQ, dev->sdr_adc_freq); for (i = 0; i < plane_size; i += 2) { - dev->sdr_fixp_mod_phase += fixp_cos(dev->sdr_fixp_src_phase); - dev->sdr_fixp_src_phase += fixp_src_phase_step; + mod_phase_step = fixp_cos32_rad(dev->sdr_fixp_src_phase, + FIXP_2PI) >> (31 - FIXP_N); + + dev->sdr_fixp_src_phase += src_phase_step; + dev->sdr_fixp_mod_phase += mod_phase_step / 4; /* * Transfer phases to [0 / 2xPI] in order to avoid variable * overflow and make it suitable for cosine implementation * used, which does not support negative angles. */ - while (dev->sdr_fixp_mod_phase < (0 * FIXP_PI)) - dev->sdr_fixp_mod_phase += (2 * FIXP_PI); - while (dev->sdr_fixp_mod_phase > (2 * FIXP_PI)) - dev->sdr_fixp_mod_phase -= (2 * FIXP_PI); + while (dev->sdr_fixp_mod_phase < FIXP_2PI) + dev->sdr_fixp_mod_phase += FIXP_2PI; + while (dev->sdr_fixp_mod_phase > FIXP_2PI) + dev->sdr_fixp_mod_phase -= FIXP_2PI; + + while (dev->sdr_fixp_src_phase > FIXP_2PI) + dev->sdr_fixp_src_phase -= FIXP_2PI; - while (dev->sdr_fixp_src_phase > (2 * FIXP_PI)) - dev->sdr_fixp_src_phase -= (2 * FIXP_PI); + fixp_i = fixp_cos32_rad(dev->sdr_fixp_mod_phase, FIXP_2PI); + fixp_q = fixp_sin32_rad(dev->sdr_fixp_mod_phase, FIXP_2PI); - fixp_i = fixp_cos(dev->sdr_fixp_mod_phase); - fixp_q = fixp_sin(dev->sdr_fixp_mod_phase); + /* Normalize fraction values represented with 32 bit precision + * to fixed point representation with FIXP_N bits */ + fixp_i >>= (31 - FIXP_N); + fixp_q >>= (31 - FIXP_N); /* convert 'fixp float' to u8 */ /* u8 = X * 127.5f + 127.5f; where X is float [-1.0 / +1.0] */ |