diff --git a/drivers/iio/adc/ad7768-1.c b/drivers/iio/adc/ad7768-1.c index 0be5e17260cf..72a960c7fb4e 100644 --- a/drivers/iio/adc/ad7768-1.c +++ b/drivers/iio/adc/ad7768-1.c @@ -21,6 +21,8 @@ #include #include #include +#include +#include #include #include @@ -78,6 +80,7 @@ #define AD7768_PWR_PWRMODE(x) FIELD_PREP(AD7768_PWR_PWRMODE_MSK, x) /* AD7768_REG_DIGITAL_FILTER */ +#define AD7768_DIG_FIL_EN_60HZ_REJ BIT(7) #define AD7768_DIG_FIL_FIL_MSK GENMASK(6, 4) #define AD7768_DIG_FIL_FIL(x) FIELD_PREP(AD7768_DIG_FIL_FIL_MSK, x) #define AD7768_DIG_FIL_DEC_MSK GENMASK(2, 0) @@ -105,6 +108,8 @@ #define AD7768_TRIGGER_SOURCE_SYNC_IDX 0 +#define AD7768_MAX_CHANNELS 1 + enum ad7768_conv_mode { AD7768_CONTINUOUS, AD7768_ONE_SHOT, @@ -126,22 +131,20 @@ enum ad7768_mclk_div { AD7768_MCLK_DIV_2 }; -enum ad7768_dec_rate { - AD7768_DEC_RATE_32 = 0, - AD7768_DEC_RATE_64 = 1, - AD7768_DEC_RATE_128 = 2, - AD7768_DEC_RATE_256 = 3, - AD7768_DEC_RATE_512 = 4, - AD7768_DEC_RATE_1024 = 5, - AD7768_DEC_RATE_8 = 9, - AD7768_DEC_RATE_16 = 10 +enum ad7768_filter_type { + AD7768_FILTER_SINC5, + AD7768_FILTER_SINC3, + AD7768_FILTER_WIDEBAND, + AD7768_FILTER_SINC3_REJ60, }; -struct ad7768_clk_configuration { - enum ad7768_mclk_div mclk_div; - enum ad7768_dec_rate dec_rate; - unsigned int clk_div; - enum ad7768_pwrmode pwrmode; +enum ad7768_filter_regval { + AD7768_FILTER_REGVAL_SINC5 = 0, + AD7768_FILTER_REGVAL_SINC5_X8 = 1, + AD7768_FILTER_REGVAL_SINC5_X16 = 2, + AD7768_FILTER_REGVAL_SINC3 = 3, + AD7768_FILTER_REGVAL_WIDEBAND = 4, + AD7768_FILTER_REGVAL_SINC3_REJ60 = 11, }; enum ad7768_scan_type { @@ -153,18 +156,36 @@ static const int ad7768_mclk_div_rates[] = { 16, 8, 4, 2, }; -static const struct ad7768_clk_configuration ad7768_clk_config[] = { - { AD7768_MCLK_DIV_2, AD7768_DEC_RATE_8, 16, AD7768_FAST_MODE }, - { AD7768_MCLK_DIV_2, AD7768_DEC_RATE_16, 32, AD7768_FAST_MODE }, - { AD7768_MCLK_DIV_2, AD7768_DEC_RATE_32, 64, AD7768_FAST_MODE }, - { AD7768_MCLK_DIV_2, AD7768_DEC_RATE_64, 128, AD7768_FAST_MODE }, - { AD7768_MCLK_DIV_2, AD7768_DEC_RATE_128, 256, AD7768_FAST_MODE }, - { AD7768_MCLK_DIV_4, AD7768_DEC_RATE_128, 512, AD7768_MED_MODE }, - { AD7768_MCLK_DIV_4, AD7768_DEC_RATE_256, 1024, AD7768_MED_MODE }, - { AD7768_MCLK_DIV_4, AD7768_DEC_RATE_512, 2048, AD7768_MED_MODE }, - { AD7768_MCLK_DIV_4, AD7768_DEC_RATE_1024, 4096, AD7768_MED_MODE }, - { AD7768_MCLK_DIV_8, AD7768_DEC_RATE_1024, 8192, AD7768_MED_MODE }, - { AD7768_MCLK_DIV_16, AD7768_DEC_RATE_1024, 16384, AD7768_ECO_MODE }, +static const int ad7768_dec_rate_values[8] = { + 8, 16, 32, 64, 128, 256, 512, 1024, +}; + +/* Decimation rate range for sinc3 filter */ +static const int ad7768_sinc3_dec_rate_range[3] = { + 32, 32, 163840, +}; + +/* + * The AD7768-1 supports three primary filter types: + * Sinc5, Sinc3, and Wideband. + * However, the filter register values can also encode additional parameters + * such as decimation rates and 60Hz rejection. This utility array separates + * the filter type from these parameters. + */ +static const int ad7768_filter_regval_to_type[] = { + [AD7768_FILTER_REGVAL_SINC5] = AD7768_FILTER_SINC5, + [AD7768_FILTER_REGVAL_SINC5_X8] = AD7768_FILTER_SINC5, + [AD7768_FILTER_REGVAL_SINC5_X16] = AD7768_FILTER_SINC5, + [AD7768_FILTER_REGVAL_SINC3] = AD7768_FILTER_SINC3, + [AD7768_FILTER_REGVAL_WIDEBAND] = AD7768_FILTER_WIDEBAND, + [AD7768_FILTER_REGVAL_SINC3_REJ60] = AD7768_FILTER_SINC3_REJ60, +}; + +static const char * const ad7768_filter_enum[] = { + [AD7768_FILTER_SINC5] = "sinc5", + [AD7768_FILTER_SINC3] = "sinc3", + [AD7768_FILTER_WIDEBAND] = "wideband", + [AD7768_FILTER_SINC3_REJ60] = "sinc3+rej60", }; static const struct iio_scan_type ad7768_scan_type[] = { @@ -183,22 +204,6 @@ static const struct iio_scan_type ad7768_scan_type[] = { }, }; -static const struct iio_chan_spec ad7768_channels[] = { - { - .type = IIO_VOLTAGE, - .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), - .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), - .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ), - .info_mask_shared_by_all_available = BIT(IIO_CHAN_INFO_SAMP_FREQ), - .indexed = 1, - .channel = 0, - .scan_index = 0, - .has_ext_scan_type = 1, - .ext_scan_type = ad7768_scan_type, - .num_ext_scan_type = ARRAY_SIZE(ad7768_scan_type), - }, -}; - struct ad7768_state { struct spi_device *spi; struct regmap *regmap; @@ -208,14 +213,17 @@ struct ad7768_state { unsigned int vcm_output_sel; struct clk *mclk; unsigned int mclk_freq; - unsigned int dec_rate; + unsigned int mclk_div; + unsigned int oversampling_ratio; + enum ad7768_filter_type filter_type; unsigned int samp_freq; - unsigned int samp_freq_avail[ARRAY_SIZE(ad7768_clk_config)]; + unsigned int samp_freq_avail[ARRAY_SIZE(ad7768_mclk_div_rates)]; + unsigned int samp_freq_avail_len; struct completion completion; struct iio_trigger *trig; struct gpio_desc *gpio_sync_in; struct gpio_desc *gpio_reset; - const char *labels[ARRAY_SIZE(ad7768_channels)]; + const char *labels[AD7768_MAX_CHANNELS]; struct gpio_chip gpiochip; bool en_spi_sync; /* @@ -326,11 +334,38 @@ static int ad7768_send_sync_pulse(struct ad7768_state *st) static void ad7768_fill_samp_freq_tbl(struct ad7768_state *st) { - unsigned int i; + unsigned int i, samp_freq_avail, freq_filtered; + unsigned int len = 0; - for (i = 0; i < ARRAY_SIZE(ad7768_clk_config); i++) - st->samp_freq_avail[i] = - DIV_ROUND_CLOSEST(st->mclk_freq, ad7768_clk_config[i].clk_div); + freq_filtered = DIV_ROUND_CLOSEST(st->mclk_freq, st->oversampling_ratio); + for (i = 0; i < ARRAY_SIZE(ad7768_mclk_div_rates); i++) { + samp_freq_avail = DIV_ROUND_CLOSEST(freq_filtered, ad7768_mclk_div_rates[i]); + /* Sampling frequency cannot be lower than the minimum of 50 SPS */ + if (samp_freq_avail < 50) + continue; + + st->samp_freq_avail[len++] = samp_freq_avail; + } + + st->samp_freq_avail_len = len; +} + +static int ad7768_set_mclk_div(struct ad7768_state *st, unsigned int mclk_div) +{ + unsigned int mclk_div_value; + + mclk_div_value = AD7768_PWR_MCLK_DIV(mclk_div); + /* + * Set power mode based on mclk_div value. + * ECO_MODE is only recommended for MCLK_DIV = 16. + */ + mclk_div_value |= mclk_div > AD7768_MCLK_DIV_16 ? + AD7768_PWR_PWRMODE(AD7768_FAST_MODE) : + AD7768_PWR_PWRMODE(AD7768_ECO_MODE); + + return regmap_update_bits(st->regmap, AD7768_REG_POWER_CLOCK, + AD7768_PWR_MCLK_DIV_MSK | AD7768_PWR_PWRMODE_MSK, + mclk_div_value); } static int ad7768_set_mode(struct ad7768_state *st, @@ -366,7 +401,7 @@ static int ad7768_scan_direct(struct iio_dev *indio_dev) * register provides 24-bit data, the precision is reduced by * right-shifting the read value by 8 bits. */ - if (st->dec_rate == 8) + if (st->oversampling_ratio == 8) readval >>= 8; /* @@ -413,22 +448,110 @@ static int ad7768_reg_access(struct iio_dev *indio_dev, return ret; } -static int ad7768_set_dig_fil(struct ad7768_state *st, - enum ad7768_dec_rate dec_rate) +static int ad7768_set_sinc3_dec_rate(struct ad7768_state *st, + unsigned int dec_rate) { - unsigned int mode; + unsigned int max_dec_rate; + u8 dec_rate_reg[2]; + u16 regval; int ret; - if (dec_rate == AD7768_DEC_RATE_8 || dec_rate == AD7768_DEC_RATE_16) - mode = AD7768_DIG_FIL_FIL(dec_rate); - else - mode = AD7768_DIG_FIL_DEC_RATE(dec_rate); + /* + * Maximum dec_rate is limited by the MCLK_DIV value and by the ODR. + * The edge case is for MCLK_DIV = 2, ODR = 50 SPS. + * max_dec_rate <= MCLK / (2 * 50) + */ + max_dec_rate = st->mclk_freq / 100; + dec_rate = clamp(dec_rate, 32, max_dec_rate); + /* + * Calculate the equivalent value to sinc3 decimation ratio + * to be written on the SINC3_DEC_RATE register: + * Value = (DEC_RATE / 32) - 1 + */ + dec_rate = DIV_ROUND_UP(dec_rate, 32) - 1; - ret = regmap_write(st->regmap, AD7768_REG_DIGITAL_FILTER, mode); - if (ret < 0) + /* + * The SINC3_DEC_RATE value is a 13-bit value split across two + * registers: MSB [12:8] and LSB [7:0]. Prepare the 13-bit value using + * FIELD_PREP() and store it with the right endianness in dec_rate_reg. + */ + regval = FIELD_PREP(GENMASK(12, 0), dec_rate); + put_unaligned_be16(regval, dec_rate_reg); + ret = regmap_bulk_write(st->regmap, AD7768_REG_SINC3_DEC_RATE_MSB, + dec_rate_reg, 2); + if (ret) return ret; - /* A sync-in pulse is required every time the filter dec rate changes */ + st->oversampling_ratio = (dec_rate + 1) * 32; + + return 0; +} + +static int ad7768_configure_dig_fil(struct iio_dev *dev, + enum ad7768_filter_type filter_type, + unsigned int dec_rate) +{ + struct ad7768_state *st = iio_priv(dev); + unsigned int dec_rate_idx, dig_filter_regval; + int ret; + + switch (filter_type) { + case AD7768_FILTER_SINC3: + dig_filter_regval = AD7768_DIG_FIL_FIL(AD7768_FILTER_REGVAL_SINC3); + break; + case AD7768_FILTER_SINC3_REJ60: + dig_filter_regval = AD7768_DIG_FIL_FIL(AD7768_FILTER_REGVAL_SINC3) | + AD7768_DIG_FIL_EN_60HZ_REJ; + break; + case AD7768_FILTER_WIDEBAND: + /* Skip decimations 8 and 16, not supported by the wideband filter */ + dec_rate_idx = find_closest(dec_rate, &ad7768_dec_rate_values[2], + ARRAY_SIZE(ad7768_dec_rate_values) - 2); + dig_filter_regval = AD7768_DIG_FIL_FIL(AD7768_FILTER_REGVAL_WIDEBAND) | + AD7768_DIG_FIL_DEC_RATE(dec_rate_idx); + /* Correct the index offset */ + dec_rate_idx += 2; + break; + case AD7768_FILTER_SINC5: + dec_rate_idx = find_closest(dec_rate, ad7768_dec_rate_values, + ARRAY_SIZE(ad7768_dec_rate_values)); + + /* + * Decimations 8 (idx 0) and 16 (idx 1) are set in the + * FILTER[6:4] field. The other decimations are set in the + * DEC_RATE[2:0] field, and the idx needs to be offsetted by two. + */ + if (dec_rate_idx == 0) + dig_filter_regval = AD7768_DIG_FIL_FIL(AD7768_FILTER_REGVAL_SINC5_X8); + else if (dec_rate_idx == 1) + dig_filter_regval = AD7768_DIG_FIL_FIL(AD7768_FILTER_REGVAL_SINC5_X16); + else + dig_filter_regval = AD7768_DIG_FIL_FIL(AD7768_FILTER_REGVAL_SINC5) | + AD7768_DIG_FIL_DEC_RATE(dec_rate_idx - 2); + break; + } + + ret = regmap_write(st->regmap, AD7768_REG_DIGITAL_FILTER, dig_filter_regval); + if (ret) + return ret; + + st->filter_type = filter_type; + /* + * The decimation for SINC3 filters are configured in different + * registers. + */ + if (filter_type == AD7768_FILTER_SINC3 || + filter_type == AD7768_FILTER_SINC3_REJ60) { + ret = ad7768_set_sinc3_dec_rate(st, dec_rate); + if (ret) + return ret; + } else { + st->oversampling_ratio = ad7768_dec_rate_values[dec_rate_idx]; + } + + ad7768_fill_samp_freq_tbl(st); + + /* A sync-in pulse is required after every configuration change */ return ad7768_send_sync_pulse(st); } @@ -551,45 +674,92 @@ static int ad7768_gpio_init(struct iio_dev *indio_dev) static int ad7768_set_freq(struct ad7768_state *st, unsigned int freq) { - unsigned int diff_new, diff_old, pwr_mode, i, idx; - int res, ret; + unsigned int idx, mclk_div; + int ret; - diff_old = U32_MAX; - idx = 0; - - res = DIV_ROUND_CLOSEST(st->mclk_freq, freq); + freq = clamp(freq, 50, 1024000); + if (freq == 0) + return -EINVAL; + mclk_div = DIV_ROUND_CLOSEST(st->mclk_freq, freq * st->oversampling_ratio); /* Find the closest match for the desired sampling frequency */ - for (i = 0; i < ARRAY_SIZE(ad7768_clk_config); i++) { - diff_new = abs(res - ad7768_clk_config[i].clk_div); - if (diff_new < diff_old) { - diff_old = diff_new; - idx = i; - } - } - - /* - * Set both the mclk_div and pwrmode with a single write to the - * POWER_CLOCK register - */ - pwr_mode = AD7768_PWR_MCLK_DIV(ad7768_clk_config[idx].mclk_div) | - AD7768_PWR_PWRMODE(ad7768_clk_config[idx].pwrmode); - ret = regmap_write(st->regmap, AD7768_REG_POWER_CLOCK, pwr_mode); - if (ret < 0) + idx = find_closest_descending(mclk_div, ad7768_mclk_div_rates, + ARRAY_SIZE(ad7768_mclk_div_rates)); + /* Set both the mclk_div and pwrmode */ + ret = ad7768_set_mclk_div(st, idx); + if (ret) return ret; - ret = ad7768_set_dig_fil(st, ad7768_clk_config[idx].dec_rate); - if (ret < 0) - return ret; - - st->dec_rate = ad7768_clk_config[idx].clk_div / - ad7768_mclk_div_rates[ad7768_clk_config[idx].mclk_div]; st->samp_freq = DIV_ROUND_CLOSEST(st->mclk_freq, - ad7768_clk_config[idx].clk_div); + ad7768_mclk_div_rates[idx] * st->oversampling_ratio); - return 0; + /* A sync-in pulse is required after every configuration change */ + return ad7768_send_sync_pulse(st); } +static int ad7768_set_filter_type_attr(struct iio_dev *dev, + const struct iio_chan_spec *chan, + unsigned int filter) +{ + struct ad7768_state *st = iio_priv(dev); + int ret; + + ret = ad7768_configure_dig_fil(dev, filter, st->oversampling_ratio); + if (ret) + return ret; + + /* Update sampling frequency */ + return ad7768_set_freq(st, st->samp_freq); +} + +static int ad7768_get_filter_type_attr(struct iio_dev *dev, + const struct iio_chan_spec *chan) +{ + struct ad7768_state *st = iio_priv(dev); + int ret; + unsigned int mode, mask; + + ret = regmap_read(st->regmap, AD7768_REG_DIGITAL_FILTER, &mode); + if (ret) + return ret; + + mask = AD7768_DIG_FIL_EN_60HZ_REJ | AD7768_DIG_FIL_FIL_MSK; + /* From the register value, get the corresponding filter type */ + return ad7768_filter_regval_to_type[FIELD_GET(mask, mode)]; +} + +static const struct iio_enum ad7768_filter_type_iio_enum = { + .items = ad7768_filter_enum, + .num_items = ARRAY_SIZE(ad7768_filter_enum), + .set = ad7768_set_filter_type_attr, + .get = ad7768_get_filter_type_attr, +}; + +static const struct iio_chan_spec_ext_info ad7768_ext_info[] = { + IIO_ENUM("filter_type", IIO_SHARED_BY_ALL, &ad7768_filter_type_iio_enum), + IIO_ENUM_AVAILABLE("filter_type", IIO_SHARED_BY_ALL, &ad7768_filter_type_iio_enum), + { } +}; + +static const struct iio_chan_spec ad7768_channels[] = { + { + .type = IIO_VOLTAGE, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | + BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), + .info_mask_shared_by_type_available = BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), + .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ), + .info_mask_shared_by_all_available = BIT(IIO_CHAN_INFO_SAMP_FREQ), + .ext_info = ad7768_ext_info, + .indexed = 1, + .channel = 0, + .scan_index = 0, + .has_ext_scan_type = 1, + .ext_scan_type = ad7768_scan_type, + .num_ext_scan_type = ARRAY_SIZE(ad7768_scan_type), + }, +}; + static int ad7768_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val, int *val2, long info) @@ -629,6 +799,11 @@ static int ad7768_read_raw(struct iio_dev *indio_dev, case IIO_CHAN_INFO_SAMP_FREQ: *val = st->samp_freq; + return IIO_VAL_INT; + + case IIO_CHAN_INFO_OVERSAMPLING_RATIO: + *val = st->oversampling_ratio; + return IIO_VAL_INT; } @@ -641,13 +816,54 @@ static int ad7768_read_avail(struct iio_dev *indio_dev, long info) { struct ad7768_state *st = iio_priv(indio_dev); + unsigned int shift; + + switch (info) { + case IIO_CHAN_INFO_OVERSAMPLING_RATIO: + /* + * Sinc3 filter allows a wider range of OSR values, so show + * the available values in range format. + */ + if (st->filter_type == AD7768_FILTER_SINC3 || + st->filter_type == AD7768_FILTER_SINC3_REJ60) { + *vals = (int *)ad7768_sinc3_dec_rate_range; + *type = IIO_VAL_INT; + return IIO_AVAIL_RANGE; + } + + shift = st->filter_type == AD7768_FILTER_SINC5 ? 0 : 2; + *vals = (int *)&ad7768_dec_rate_values[shift]; + *length = ARRAY_SIZE(ad7768_dec_rate_values) - shift; + *type = IIO_VAL_INT; + return IIO_AVAIL_LIST; + case IIO_CHAN_INFO_SAMP_FREQ: + *vals = (int *)st->samp_freq_avail; + *length = st->samp_freq_avail_len; + *type = IIO_VAL_INT; + return IIO_AVAIL_LIST; + default: + return -EINVAL; + } +} + +static int __ad7768_write_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int val, int val2, long info) +{ + struct ad7768_state *st = iio_priv(indio_dev); + int ret; switch (info) { case IIO_CHAN_INFO_SAMP_FREQ: - *vals = (int *)st->samp_freq_avail; - *length = ARRAY_SIZE(ad7768_clk_config); - *type = IIO_VAL_INT; - return IIO_AVAIL_LIST; + return ad7768_set_freq(st, val); + + case IIO_CHAN_INFO_OVERSAMPLING_RATIO: + ret = ad7768_configure_dig_fil(indio_dev, st->filter_type, val); + if (ret) + return ret; + + /* Update sampling frequency */ + return ad7768_set_freq(st, st->samp_freq); default: return -EINVAL; } @@ -657,14 +873,15 @@ static int ad7768_write_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int val, int val2, long info) { - struct ad7768_state *st = iio_priv(indio_dev); + int ret; - switch (info) { - case IIO_CHAN_INFO_SAMP_FREQ: - return ad7768_set_freq(st, val); - default: - return -EINVAL; - } + if (!iio_device_claim_direct(indio_dev)) + return -EBUSY; + + ret = __ad7768_write_raw(indio_dev, chan, val, val2, info); + iio_device_release_direct(indio_dev); + + return ret; } static int ad7768_read_label(struct iio_dev *indio_dev, @@ -680,7 +897,7 @@ static int ad7768_get_current_scan_type(const struct iio_dev *indio_dev, { struct ad7768_state *st = iio_priv(indio_dev); - return st->dec_rate == 8 ? + return st->oversampling_ratio == 8 ? AD7768_SCAN_TYPE_HIGH_SPEED : AD7768_SCAN_TYPE_NORMAL; } @@ -816,6 +1033,14 @@ static int ad7768_setup(struct iio_dev *indio_dev) return ret; } + /* + * Set Default Digital Filter configuration: + * SINC5 filter with x32 Decimation rate + */ + ret = ad7768_configure_dig_fil(indio_dev, AD7768_FILTER_SINC5, 32); + if (ret) + return ret; + /* Set the default sampling frequency to 32000 kSPS */ return ad7768_set_freq(st, 32000); } @@ -1150,7 +1375,6 @@ static int ad7768_probe(struct spi_device *spi) return PTR_ERR(st->mclk); st->mclk_freq = clk_get_rate(st->mclk); - ad7768_fill_samp_freq_tbl(st); indio_dev->channels = ad7768_channels; indio_dev->num_channels = ARRAY_SIZE(ad7768_channels);