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| author |  David Lechner <dlechner@baylibre.com>
| 2023-09-29 12:23:21 -0500 |
|---|---|---|
| committer |  Jonathan Cameron <Jonathan.Cameron@huawei.com>
| 2023-10-05 14:44:05 +0100 |
| commit | 500d7640f63d557c397f74b7d5bf8c81377b50b3 (patch) | |
| tree | cf64c916da050216eccb94a53c7dbf9a4f7dca38 /drivers/staging/iio | |
| parent | staging: iio: resolver: ad2s1210: refactor setting excitation frequency (diff) | |
| download | linux-500d7640f63d557c397f74b7d5bf8c81377b50b3.tar.gz linux-500d7640f63d557c397f74b7d5bf8c81377b50b3.tar.bz2 linux-500d7640f63d557c397f74b7d5bf8c81377b50b3.zip | |
staging: iio: resolver: ad2s1210: read excitation frequency from control register
This modifies the ad2s1210_show_fexcit() function to read the excitation
frequency from the control register. This way we don't have to keep
track of the value and don't risk returning a stale value.
Signed-off-by: David Lechner <dlechner@baylibre.com>
Link: https://lore.kernel.org/r/20230929-ad2s1210-mainline-v3-16-fa4364281745@baylibre.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Diffstat (limited to 'drivers/staging/iio')
| -rw-r--r-- | drivers/staging/iio/resolver/ad2s1210.c | 19 |
1 files changed, 15 insertions, 4 deletions
diff --git a/drivers/staging/iio/resolver/ad2s1210.c b/drivers/staging/iio/resolver/ad2s1210.c index 2b728863a3ff..67d8af0dd7ae 100644 --- a/drivers/staging/iio/resolver/ad2s1210.c +++ b/drivers/staging/iio/resolver/ad2s1210.c @@ -76,7 +76,6 @@ struct ad2s1210_state { struct regmap *regmap; /** The external oscillator frequency in Hz. */ unsigned long clkin_hz; - unsigned int fexcit; bool hysteresis; u8 resolution; /** For reading raw sample value via SPI. */ @@ -207,8 +206,6 @@ static int ad2s1210_reinit_excitation_frequency(struct ad2s1210_state *st, if (ret < 0) return ret; - st->fexcit = fexcit; - /* * Software reset reinitializes the excitation frequency output. * It does not reset any of the configuration registers. @@ -233,8 +230,22 @@ static ssize_t ad2s1210_show_fexcit(struct device *dev, char *buf) { struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev)); + unsigned int value; + u16 fexcit; + int ret; - return sprintf(buf, "%u\n", st->fexcit); + mutex_lock(&st->lock); + ret = regmap_read(st->regmap, AD2S1210_REG_EXCIT_FREQ, &value); + if (ret < 0) + goto error_ret; + + fexcit = value * st->clkin_hz / (1 << 15); + + ret = sprintf(buf, "%u\n", fexcit); + +error_ret: + mutex_unlock(&st->lock); + return ret; } static ssize_t ad2s1210_store_fexcit(struct device *dev, |