diff options
Diffstat (limited to 'drivers/iio/adc/vf610_adc.c')
| -rw-r--r-- | drivers/iio/adc/vf610_adc.c | 96 |
1 files changed, 62 insertions, 34 deletions
diff --git a/drivers/iio/adc/vf610_adc.c b/drivers/iio/adc/vf610_adc.c index 8ec353c01d98..56292ae4538d 100644 --- a/drivers/iio/adc/vf610_adc.c +++ b/drivers/iio/adc/vf610_adc.c @@ -141,9 +141,13 @@ struct vf610_adc { struct regulator *vref; struct vf610_adc_feature adc_feature; + u32 sample_freq_avail[5]; + struct completion completion; }; +static const u32 vf610_hw_avgs[] = { 1, 4, 8, 16, 32 }; + #define VF610_ADC_CHAN(_idx, _chan_type) { \ .type = (_chan_type), \ .indexed = 1, \ @@ -180,35 +184,47 @@ static const struct iio_chan_spec vf610_adc_iio_channels[] = { /* sentinel */ }; -/* - * ADC sample frequency, unit is ADCK cycles. - * ADC clk source is ipg clock, which is the same as bus clock. - * - * ADC conversion time = SFCAdder + AverageNum x (BCT + LSTAdder) - * SFCAdder: fixed to 6 ADCK cycles - * AverageNum: 1, 4, 8, 16, 32 samples for hardware average. - * BCT (Base Conversion Time): fixed to 25 ADCK cycles for 12 bit mode - * LSTAdder(Long Sample Time): fixed to 3 ADCK cycles - * - * By default, enable 12 bit resolution mode, clock source - * set to ipg clock, So get below frequency group: - */ -static const u32 vf610_sample_freq_avail[5] = -{1941176, 559332, 286957, 145374, 73171}; +static inline void vf610_adc_calculate_rates(struct vf610_adc *info) +{ + unsigned long adck_rate, ipg_rate = clk_get_rate(info->clk); + int i; + + /* + * Calculate ADC sample frequencies + * Sample time unit is ADCK cycles. ADCK clk source is ipg clock, + * which is the same as bus clock. + * + * ADC conversion time = SFCAdder + AverageNum x (BCT + LSTAdder) + * SFCAdder: fixed to 6 ADCK cycles + * AverageNum: 1, 4, 8, 16, 32 samples for hardware average. + * BCT (Base Conversion Time): fixed to 25 ADCK cycles for 12 bit mode + * LSTAdder(Long Sample Time): fixed to 3 ADCK cycles + */ + adck_rate = ipg_rate / info->adc_feature.clk_div; + for (i = 0; i < ARRAY_SIZE(vf610_hw_avgs); i++) + info->sample_freq_avail[i] = + adck_rate / (6 + vf610_hw_avgs[i] * (25 + 3)); +} static inline void vf610_adc_cfg_init(struct vf610_adc *info) { + struct vf610_adc_feature *adc_feature = &info->adc_feature; + /* set default Configuration for ADC controller */ - info->adc_feature.clk_sel = VF610_ADCIOC_BUSCLK_SET; - info->adc_feature.vol_ref = VF610_ADCIOC_VR_VREF_SET; + adc_feature->clk_sel = VF610_ADCIOC_BUSCLK_SET; + adc_feature->vol_ref = VF610_ADCIOC_VR_VREF_SET; + + adc_feature->calibration = true; + adc_feature->ovwren = true; + + adc_feature->res_mode = 12; + adc_feature->sample_rate = 1; + adc_feature->lpm = true; - info->adc_feature.calibration = true; - info->adc_feature.ovwren = true; + /* Use a save ADCK which is below 20MHz on all devices */ + adc_feature->clk_div = 8; - info->adc_feature.clk_div = 1; - info->adc_feature.res_mode = 12; - info->adc_feature.sample_rate = 1; - info->adc_feature.lpm = true; + vf610_adc_calculate_rates(info); } static void vf610_adc_cfg_post_set(struct vf610_adc *info) @@ -259,7 +275,6 @@ static void vf610_adc_cfg_post_set(struct vf610_adc *info) static void vf610_adc_calibration(struct vf610_adc *info) { int adc_gc, hc_cfg; - int timeout; if (!info->adc_feature.calibration) return; @@ -271,9 +286,7 @@ static void vf610_adc_calibration(struct vf610_adc *info) adc_gc = readl(info->regs + VF610_REG_ADC_GC); writel(adc_gc | VF610_ADC_CAL, info->regs + VF610_REG_ADC_GC); - timeout = wait_for_completion_timeout - (&info->completion, VF610_ADC_TIMEOUT); - if (timeout == 0) + if (!wait_for_completion_timeout(&info->completion, VF610_ADC_TIMEOUT)) dev_err(info->dev, "Timeout for adc calibration\n"); adc_gc = readl(info->regs + VF610_REG_ADC_GS); @@ -290,12 +303,10 @@ static void vf610_adc_cfg_set(struct vf610_adc *info) cfg_data = readl(info->regs + VF610_REG_ADC_CFG); - /* low power configuration */ cfg_data &= ~VF610_ADC_ADLPC_EN; if (adc_feature->lpm) cfg_data |= VF610_ADC_ADLPC_EN; - /* disable high speed */ cfg_data &= ~VF610_ADC_ADHSC_EN; writel(cfg_data, info->regs + VF610_REG_ADC_CFG); @@ -435,10 +446,27 @@ static irqreturn_t vf610_adc_isr(int irq, void *dev_id) return IRQ_HANDLED; } -static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("1941176, 559332, 286957, 145374, 73171"); +static ssize_t vf610_show_samp_freq_avail(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct vf610_adc *info = iio_priv(dev_to_iio_dev(dev)); + size_t len = 0; + int i; + + for (i = 0; i < ARRAY_SIZE(info->sample_freq_avail); i++) + len += scnprintf(buf + len, PAGE_SIZE - len, + "%u ", info->sample_freq_avail[i]); + + /* replace trailing space by newline */ + buf[len - 1] = '\n'; + + return len; +} + +static IIO_DEV_ATTR_SAMP_FREQ_AVAIL(vf610_show_samp_freq_avail); static struct attribute *vf610_attributes[] = { - &iio_const_attr_sampling_frequency_available.dev_attr.attr, + &iio_dev_attr_sampling_frequency_available.dev_attr.attr, NULL }; @@ -502,7 +530,7 @@ static int vf610_read_raw(struct iio_dev *indio_dev, return IIO_VAL_FRACTIONAL_LOG2; case IIO_CHAN_INFO_SAMP_FREQ: - *val = vf610_sample_freq_avail[info->adc_feature.sample_rate]; + *val = info->sample_freq_avail[info->adc_feature.sample_rate]; *val2 = 0; return IIO_VAL_INT; @@ -525,9 +553,9 @@ static int vf610_write_raw(struct iio_dev *indio_dev, switch (mask) { case IIO_CHAN_INFO_SAMP_FREQ: for (i = 0; - i < ARRAY_SIZE(vf610_sample_freq_avail); + i < ARRAY_SIZE(info->sample_freq_avail); i++) - if (val == vf610_sample_freq_avail[i]) { + if (val == info->sample_freq_avail[i]) { info->adc_feature.sample_rate = i; vf610_adc_sample_set(info); return 0; |