From 8e2efac7d2873ed81b536b8b1462b5e1eeefc2ab Mon Sep 17 00:00:00 2001 From: Antti Palosaari Date: Wed, 7 Aug 2013 11:27:21 -0300 Subject: [PATCH] [media] msi3101: add stream format 336 I+Q pairs per frame That one seem to have 12-bit resolution. Use it for streams that has sampling rate 6 <= rate (Msps) < 8, between 6 and 8Msps. Signed-off-by: Antti Palosaari Signed-off-by: Mauro Carvalho Chehab --- drivers/staging/media/msi3101/sdr-msi3101.c | 95 +++++++++++++++++++++ 1 file changed, 95 insertions(+) diff --git a/drivers/staging/media/msi3101/sdr-msi3101.c b/drivers/staging/media/msi3101/sdr-msi3101.c index 56f97577a760..c4bd9630eea1 100644 --- a/drivers/staging/media/msi3101/sdr-msi3101.c +++ b/drivers/staging/media/msi3101/sdr-msi3101.c @@ -604,6 +604,98 @@ static int msi3101_convert_stream_384(struct msi3101_state *s, u32 *dst, return dst_len; } +/* + * Converts signed 12-bit integer into 32-bit IEEE floating point + * representation. + */ +static u32 msi3101_convert_sample_336(struct msi3101_state *s, u16 x) +{ + u32 msb, exponent, fraction, sign; + + /* Zero is special */ + if (!x) + return 0; + + /* Negative / positive value */ + if (x & (1 << 11)) { + x = -x; + x &= 0x7ff; /* result is 11 bit ... + sign */ + sign = 1 << 31; + } else { + sign = 0 << 31; + } + + /* Get location of the most significant bit */ + msb = __fls(x); + + /* + * Use a rotate instead of a shift because that works both leftwards + * and rightwards due to the mod(32) behaviour. This means we don't + * need to check to see if we are above 2^24 or not. + */ + fraction = ror32(x, (msb - I2F_FRAC_BITS) & 0x1f) & I2F_MASK; + exponent = (127 + msb) << I2F_FRAC_BITS; + + return (fraction + exponent) | sign; +} + +static int msi3101_convert_stream_336(struct msi3101_state *s, u32 *dst, + u8 *src, unsigned int src_len) +{ + int i, j, i_max, dst_len = 0; + u16 sample[2]; + u32 sample_num[3]; + + /* There could be 1-3 1024 bytes URB frames */ + i_max = src_len / 1024; + + for (i = 0; i < i_max; i++) { + sample_num[i] = src[3] << 24 | src[2] << 16 | src[1] << 8 | src[0] << 0; + if (i == 0 && s->next_sample != sample_num[0]) { + dev_dbg_ratelimited(&s->udev->dev, + "%d samples lost, %d %08x:%08x\n", + sample_num[0] - s->next_sample, + src_len, s->next_sample, sample_num[0]); + } + + /* + * Dump all unknown 'garbage' data - maybe we will discover + * someday if there is something rational... + */ + dev_dbg_ratelimited(&s->udev->dev, "%*ph\n", 12, &src[4]); + + src += 16; + for (j = 0; j < 1008; j += 3) { + sample[0] = (src[j + 0] & 0xff) >> 0 | (src[j + 1] & 0x0f) << 8; + sample[1] = (src[j + 1] & 0xf0) >> 4 | (src[j + 2] & 0xff) << 4; + + *dst++ = msi3101_convert_sample_336(s, sample[0]); + *dst++ = msi3101_convert_sample_336(s, sample[1]); + } + /* 336 x I+Q 32bit float samples */ + dst_len += 336 * 2 * 4; + src += 1008; + } + + /* calculate samping rate and output it in 10 seconds intervals */ + if ((s->jiffies + msecs_to_jiffies(10000)) <= jiffies) { + unsigned long jiffies_now = jiffies; + unsigned long msecs = jiffies_to_msecs(jiffies_now) - jiffies_to_msecs(s->jiffies); + unsigned int samples = sample_num[i_max - 1] - s->sample; + s->jiffies = jiffies_now; + s->sample = sample_num[i_max - 1]; + dev_dbg(&s->udev->dev, + "slen=%d samples=%u msecs=%lu sampling rate=%lu\n", + src_len, samples, msecs, + samples * 1000UL / msecs); + } + + /* next sample (sample = sample + i * 336) */ + s->next_sample = sample_num[i_max - 1] + 336; + + return dst_len; +} + /* * Converts signed 14-bit integer into 32-bit IEEE floating point * representation. @@ -1097,6 +1189,9 @@ static int msi3101_set_usb_adc(struct msi3101_state *s) if (f_sr < 6000000) { s->convert_stream = msi3101_convert_stream_252; reg7 = 0x00009407; + } else if (f_sr < 8000000) { + s->convert_stream = msi3101_convert_stream_336; + reg7 = 0x00008507; } else { s->convert_stream = msi3101_convert_stream_384; reg7 = 0x0000a507; -- 2.20.1