diff options
| -rw-r--r-- | drivers/staging/iio/resolver/ad2s1210.c | 66 |
1 files changed, 34 insertions, 32 deletions
diff --git a/drivers/staging/iio/resolver/ad2s1210.c b/drivers/staging/iio/resolver/ad2s1210.c index 5744f1673cba..2b728863a3ff 100644 --- a/drivers/staging/iio/resolver/ad2s1210.c +++ b/drivers/staging/iio/resolver/ad2s1210.c @@ -51,12 +51,11 @@ #define AD2S1210_MIN_CLKIN 6144000 #define AD2S1210_MAX_CLKIN 10240000 #define AD2S1210_MIN_EXCIT 2000 +#define AD2S1210_DEF_EXCIT 10000 #define AD2S1210_MAX_EXCIT 20000 #define AD2S1210_MIN_FCW 0x4 #define AD2S1210_MAX_FCW 0x50 -#define AD2S1210_DEF_EXCIT 10000 - enum ad2s1210_mode { MOD_POS = 0b00, MOD_VEL = 0b01, @@ -189,18 +188,32 @@ static int ad2s1210_regmap_reg_read(void *context, unsigned int reg, return 0; } -static inline -int ad2s1210_update_frequency_control_word(struct ad2s1210_state *st) +/* + * Sets the excitation frequency and performs software reset. + * + * Must be called with lock held. + */ +static int ad2s1210_reinit_excitation_frequency(struct ad2s1210_state *st, + u16 fexcit) { - unsigned char fcw; + int ret; + u8 fcw; - fcw = (unsigned char)(st->fexcit * (1 << 15) / st->clkin_hz); - if (fcw < AD2S1210_MIN_FCW || fcw > AD2S1210_MAX_FCW) { - dev_err(&st->sdev->dev, "ad2s1210: FCW out of range\n"); + fcw = fexcit * (1 << 15) / st->clkin_hz; + if (fcw < AD2S1210_MIN_FCW || fcw > AD2S1210_MAX_FCW) return -ERANGE; - } - return regmap_write(st->regmap, AD2S1210_REG_EXCIT_FREQ, fcw); + ret = regmap_write(st->regmap, AD2S1210_REG_EXCIT_FREQ, fcw); + if (ret < 0) + return ret; + + st->fexcit = fexcit; + + /* + * Software reset reinitializes the excitation frequency output. + * It does not reset any of the configuration registers. + */ + return regmap_write(st->regmap, AD2S1210_REG_SOFT_RESET, 0); } static int ad2s1210_set_resolution_gpios(struct ad2s1210_state *st, @@ -215,11 +228,6 @@ static int ad2s1210_set_resolution_gpios(struct ad2s1210_state *st, bitmap); } -static inline int ad2s1210_soft_reset(struct ad2s1210_state *st) -{ - return regmap_write(st->regmap, AD2S1210_REG_SOFT_RESET, 0); -} - static ssize_t ad2s1210_show_fexcit(struct device *dev, struct device_attribute *attr, char *buf) @@ -234,27 +242,24 @@ static ssize_t ad2s1210_store_fexcit(struct device *dev, const char *buf, size_t len) { struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev)); - unsigned int fexcit; + u16 fexcit; int ret; - ret = kstrtouint(buf, 10, &fexcit); - if (ret < 0) - return ret; - if (fexcit < AD2S1210_MIN_EXCIT || fexcit > AD2S1210_MAX_EXCIT) { - dev_err(dev, - "ad2s1210: excitation frequency out of range\n"); + ret = kstrtou16(buf, 10, &fexcit); + if (ret < 0 || fexcit < AD2S1210_MIN_EXCIT || fexcit > AD2S1210_MAX_EXCIT) return -EINVAL; - } + mutex_lock(&st->lock); - st->fexcit = fexcit; - ret = ad2s1210_update_frequency_control_word(st); + ret = ad2s1210_reinit_excitation_frequency(st, fexcit); if (ret < 0) goto error_ret; - ret = ad2s1210_soft_reset(st); + + ret = len; + error_ret: mutex_unlock(&st->lock); - return ret < 0 ? ret : len; + return ret; } static ssize_t ad2s1210_show_resolution(struct device *dev, @@ -551,10 +556,8 @@ static int ad2s1210_initial(struct ad2s1210_state *st) if (ret < 0) goto error_ret; - ret = ad2s1210_update_frequency_control_word(st); - if (ret < 0) - goto error_ret; - ret = ad2s1210_soft_reset(st); + ret = ad2s1210_reinit_excitation_frequency(st, AD2S1210_DEF_EXCIT); + error_ret: mutex_unlock(&st->lock); return ret; @@ -698,7 +701,6 @@ static int ad2s1210_probe(struct spi_device *spi) st->sdev = spi; st->hysteresis = true; st->resolution = 12; - st->fexcit = AD2S1210_DEF_EXCIT; ret = ad2s1210_setup_clocks(st); if (ret < 0) |