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iio:adis16400: Increase samplerate precession

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The devices supported by this drivers support sample rates with less than one
sample per second. To support this increase the samplerate precession to allow
setting (and reading) the samplerate with a milli-HZ precession.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
This commit is contained in:
Lars-Peter Clausen 2013-01-16 12:48:00 +00:00 committed by Jonathan Cameron
parent d6b09bd85d
commit b24150e31a
1 changed files with 18 additions and 14 deletions
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32
drivers/iio/imu/adis16400_core.c
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@ -53,16 +53,15 @@ static int adis16334_get_freq(struct adis16400_state *st)
t >>= ADIS16334_RATE_DIV_SHIFT; t >>= ADIS16334_RATE_DIV_SHIFT;
return (8192 >> t) / 10; return 819200 >> t;
} }
static int adis16334_set_freq(struct adis16400_state *st, unsigned int freq) static int adis16334_set_freq(struct adis16400_state *st, unsigned int freq)
{ {
unsigned int t; unsigned int t;
freq *= 10; if (freq < 819200)
if (freq < 8192) t = ilog2(819200 / freq);
t = ilog2(8192 / freq);
else else
t = 0; t = 0;
@ -84,7 +83,7 @@ static int adis16400_get_freq(struct adis16400_state *st)
if (ret < 0) if (ret < 0)
return ret; return ret;
sps = (t & ADIS16400_SMPL_PRD_TIME_BASE) ? 53 : 1638; sps = (t & ADIS16400_SMPL_PRD_TIME_BASE) ? 52851 : 1638404;
sps /= (t & ADIS16400_SMPL_PRD_DIV_MASK) + 1; sps /= (t & ADIS16400_SMPL_PRD_DIV_MASK) + 1;
return sps; return sps;
@ -94,7 +93,7 @@ static int adis16400_set_freq(struct adis16400_state *st, unsigned int freq)
{ {
unsigned int t; unsigned int t;
t = 1638 / freq; t = 1638404 / freq;
if (t > 0) if (t > 0)
t--; t--;
t &= ADIS16400_SMPL_PRD_DIV_MASK; t &= ADIS16400_SMPL_PRD_DIV_MASK;
@ -119,7 +118,7 @@ static ssize_t adis16400_read_frequency(struct device *dev,
if (ret < 0) if (ret < 0)
return ret; return ret;
return sprintf(buf, "%d\n", ret); return sprintf(buf, "%d.%.3d\n", ret / 1000, ret % 1000);
} }
static const unsigned adis16400_3db_divisors[] = { static const unsigned adis16400_3db_divisors[] = {
@ -158,14 +157,16 @@ static ssize_t adis16400_write_frequency(struct device *dev,
{ {
struct iio_dev *indio_dev = dev_to_iio_dev(dev); struct iio_dev *indio_dev = dev_to_iio_dev(dev);
struct adis16400_state *st = iio_priv(indio_dev); struct adis16400_state *st = iio_priv(indio_dev);
long val; int i, f, val;
int ret; int ret;
ret = kstrtol(buf, 10, &val); ret = iio_str_to_fixpoint(buf, 100, &i, &f);
if (ret) if (ret)
return ret; return ret;
if (val == 0) val = i * 1000 + f;
if (val <= 0)
return -EINVAL; return -EINVAL;
mutex_lock(&indio_dev->mlock); mutex_lock(&indio_dev->mlock);
@ -281,7 +282,8 @@ static int adis16400_write_raw(struct iio_dev *indio_dev,
return sps; return sps;
} }
ret = adis16400_set_filter(indio_dev, sps, val); ret = adis16400_set_filter(indio_dev, sps,
val * 1000 + val2 / 1000);
mutex_unlock(&indio_dev->mlock); mutex_unlock(&indio_dev->mlock);
return ret; return ret;
default: default:
@ -355,9 +357,11 @@ static int adis16400_read_raw(struct iio_dev *indio_dev,
return ret; return ret;
} }
ret = st->variant->get_freq(st); ret = st->variant->get_freq(st);
if (ret >= 0) if (ret >= 0) {
*val = ret / adis16400_3db_divisors[val16 & 0x07]; ret /= adis16400_3db_divisors[val16 & 0x07];
*val2 = 0; *val = ret / 1000;
*val2 = (ret % 1000) * 1000;
}
mutex_unlock(&indio_dev->mlock); mutex_unlock(&indio_dev->mlock);
if (ret < 0) if (ret < 0)
return ret; return ret;