// SPDX-License-Identifier: GPL-2.0 /* * Analog Devices AD7466/7/8 AD7476/5/7/8 (A) SPI ADC driver * TI ADC081S/ADC101S/ADC121S 8/10/12-bit SPI ADC driver * * Copyright 2010 Analog Devices Inc. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include struct ad7476_state; struct ad7476_chip_info { unsigned int int_vref_uv; struct iio_chan_spec channel[2]; /* channels used when convst gpio is defined */ struct iio_chan_spec convst_channel[2]; void (*reset)(struct ad7476_state *); bool has_vref; bool has_vdrive; }; struct ad7476_state { struct spi_device *spi; const struct ad7476_chip_info *chip_info; struct regulator *ref_reg; struct gpio_desc *convst_gpio; struct spi_transfer xfer; struct spi_message msg; /* * DMA (thus cache coherency maintenance) may require the * transfer buffers to live in their own cache lines. * Make the buffer large enough for one 16 bit sample and one 64 bit * aligned 64 bit timestamp. */ unsigned char data[ALIGN(2, sizeof(s64)) + sizeof(s64)] __aligned(IIO_DMA_MINALIGN); }; enum ad7476_supported_device_ids { ID_AD7091, ID_AD7091R, ID_AD7273, ID_AD7274, ID_AD7276, ID_AD7277, ID_AD7278, ID_AD7466, ID_AD7467, ID_AD7468, ID_AD7475, ID_AD7495, ID_AD7940, ID_ADC081S, ID_ADC101S, ID_ADC121S, ID_ADS7866, ID_ADS7867, ID_ADS7868, ID_LTC2314_14, }; static void ad7091_convst(struct ad7476_state *st) { if (!st->convst_gpio) return; gpiod_set_value(st->convst_gpio, 0); udelay(1); /* CONVST pulse width: 10 ns min */ gpiod_set_value(st->convst_gpio, 1); udelay(1); /* Conversion time: 650 ns max */ } static irqreturn_t ad7476_trigger_handler(int irq, void *p) { struct iio_poll_func *pf = p; struct iio_dev *indio_dev = pf->indio_dev; struct ad7476_state *st = iio_priv(indio_dev); int b_sent; ad7091_convst(st); b_sent = spi_sync(st->spi, &st->msg); if (b_sent < 0) goto done; iio_push_to_buffers_with_timestamp(indio_dev, st->data, iio_get_time_ns(indio_dev)); done: iio_trigger_notify_done(indio_dev->trig); return IRQ_HANDLED; } static void ad7091_reset(struct ad7476_state *st) { /* Any transfers with 8 scl cycles will reset the device */ spi_read(st->spi, st->data, 1); } static int ad7476_scan_direct(struct ad7476_state *st) { int ret; ad7091_convst(st); ret = spi_sync(st->spi, &st->msg); if (ret) return ret; return be16_to_cpup((__be16 *)st->data); } static int ad7476_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val, int *val2, long m) { int ret; struct ad7476_state *st = iio_priv(indio_dev); int scale_uv; switch (m) { case IIO_CHAN_INFO_RAW: ret = iio_device_claim_direct_mode(indio_dev); if (ret) return ret; ret = ad7476_scan_direct(st); iio_device_release_direct_mode(indio_dev); if (ret < 0) return ret; *val = (ret >> st->chip_info->channel[0].scan_type.shift) & GENMASK(st->chip_info->channel[0].scan_type.realbits - 1, 0); return IIO_VAL_INT; case IIO_CHAN_INFO_SCALE: if (st->ref_reg) { scale_uv = regulator_get_voltage(st->ref_reg); if (scale_uv < 0) return scale_uv; } else { scale_uv = st->chip_info->int_vref_uv; } *val = scale_uv / 1000; *val2 = chan->scan_type.realbits; return IIO_VAL_FRACTIONAL_LOG2; } return -EINVAL; } #define _AD7476_CHAN(bits, _shift, _info_mask_sep) \ { \ .type = IIO_VOLTAGE, \ .indexed = 1, \ .info_mask_separate = _info_mask_sep, \ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ .scan_type = { \ .sign = 'u', \ .realbits = (bits), \ .storagebits = 16, \ .shift = (_shift), \ .endianness = IIO_BE, \ }, \ } #define ADC081S_CHAN(bits) _AD7476_CHAN((bits), 12 - (bits), \ BIT(IIO_CHAN_INFO_RAW)) #define AD7476_CHAN(bits) _AD7476_CHAN((bits), 13 - (bits), \ BIT(IIO_CHAN_INFO_RAW)) #define AD7940_CHAN(bits) _AD7476_CHAN((bits), 15 - (bits), \ BIT(IIO_CHAN_INFO_RAW)) #define AD7091R_CHAN(bits) _AD7476_CHAN((bits), 16 - (bits), 0) #define AD7091R_CONVST_CHAN(bits) _AD7476_CHAN((bits), 16 - (bits), \ BIT(IIO_CHAN_INFO_RAW)) #define ADS786X_CHAN(bits) _AD7476_CHAN((bits), 12 - (bits), \ BIT(IIO_CHAN_INFO_RAW)) static const struct ad7476_chip_info ad7476_chip_info_tbl[] = { [ID_AD7091] = { .channel[0] = AD7091R_CHAN(12), .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1), .convst_channel[0] = AD7091R_CONVST_CHAN(12), .convst_channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1), .reset = ad7091_reset, }, [ID_AD7091R] = { .channel[0] = AD7091R_CHAN(12), .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1), .convst_channel[0] = AD7091R_CONVST_CHAN(12), .convst_channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1), .int_vref_uv = 2500000, .has_vref = true, .reset = ad7091_reset, }, [ID_AD7273] = { .channel[0] = AD7940_CHAN(10), .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1), .has_vref = true, }, [ID_AD7274] = { .channel[0] = AD7940_CHAN(12), .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1), .has_vref = true, }, [ID_AD7276] = { .channel[0] = AD7940_CHAN(12), .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1), }, [ID_AD7277] = { .channel[0] = AD7940_CHAN(10), .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1), }, [ID_AD7278] = { .channel[0] = AD7940_CHAN(8), .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1), }, [ID_AD7466] = { .channel[0] = AD7476_CHAN(12), .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1), }, [ID_AD7467] = { .channel[0] = AD7476_CHAN(10), .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1), }, [ID_AD7468] = { .channel[0] = AD7476_CHAN(8), .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1), }, [ID_AD7475] = { .channel[0] = AD7476_CHAN(12), .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1), .has_vref = true, .has_vdrive = true, }, [ID_AD7495] = { .channel[0] = AD7476_CHAN(12), .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1), .int_vref_uv = 2500000, .has_vdrive = true, }, [ID_AD7940] = { .channel[0] = AD7940_CHAN(14), .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1), }, [ID_ADC081S] = { .channel[0] = ADC081S_CHAN(8), .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1), }, [ID_ADC101S] = { .channel[0] = ADC081S_CHAN(10), .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1), }, [ID_ADC121S] = { .channel[0] = ADC081S_CHAN(12), .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1), }, [ID_ADS7866] = { .channel[0] = ADS786X_CHAN(12), .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1), }, [ID_ADS7867] = { .channel[0] = ADS786X_CHAN(10), .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1), }, [ID_ADS7868] = { .channel[0] = ADS786X_CHAN(8), .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1), }, [ID_LTC2314_14] = { .channel[0] = AD7940_CHAN(14), .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1), .has_vref = true, }, }; static const struct iio_info ad7476_info = { .read_raw = &ad7476_read_raw, }; static void ad7476_reg_disable(void *data) { struct regulator *reg = data; regulator_disable(reg); } static int ad7476_probe(struct spi_device *spi) { struct ad7476_state *st; struct iio_dev *indio_dev; struct regulator *reg; int ret; indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st)); if (!indio_dev) return -ENOMEM; st = iio_priv(indio_dev); st->chip_info = &ad7476_chip_info_tbl[spi_get_device_id(spi)->driver_data]; reg = devm_regulator_get(&spi->dev, "vcc"); if (IS_ERR(reg)) return PTR_ERR(reg); ret = regulator_enable(reg); if (ret) return ret; ret = devm_add_action_or_reset(&spi->dev, ad7476_reg_disable, reg); if (ret) return ret; /* Either vcc or vref (below) as appropriate */ if (!st->chip_info->int_vref_uv) st->ref_reg = reg; if (st->chip_info->has_vref) { /* If a device has an internal reference vref is optional */ if (st->chip_info->int_vref_uv) { reg = devm_regulator_get_optional(&spi->dev, "vref"); if (IS_ERR(reg) && (PTR_ERR(reg) != -ENODEV)) return PTR_ERR(reg); } else { reg = devm_regulator_get(&spi->dev, "vref"); if (IS_ERR(reg)) return PTR_ERR(reg); } if (!IS_ERR(reg)) { ret = regulator_enable(reg); if (ret) return ret; ret = devm_add_action_or_reset(&spi->dev, ad7476_reg_disable, reg); if (ret) return ret; st->ref_reg = reg; } else { /* * Can only get here if device supports both internal * and external reference, but the regulator connected * to the external reference is not connected. * Set the reference regulator pointer to NULL to * indicate this. */ st->ref_reg = NULL; } } if (st->chip_info->has_vdrive) { ret = devm_regulator_get_enable(&spi->dev, "vdrive"); if (ret) return ret; } st->convst_gpio = devm_gpiod_get_optional(&spi->dev, "adi,conversion-start", GPIOD_OUT_LOW); if (IS_ERR(st->convst_gpio)) return PTR_ERR(st->convst_gpio); st->spi = spi; indio_dev->name = spi_get_device_id(spi)->name; indio_dev->modes = INDIO_DIRECT_MODE; indio_dev->channels = st->chip_info->channel; indio_dev->num_channels = 2; indio_dev->info = &ad7476_info; if (st->convst_gpio) indio_dev->channels = st->chip_info->convst_channel; /* Setup default message */ st->xfer.rx_buf = &st->data; st->xfer.len = st->chip_info->channel[0].scan_type.storagebits / 8; spi_message_init(&st->msg); spi_message_add_tail(&st->xfer, &st->msg); ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev, NULL, &ad7476_trigger_handler, NULL); if (ret) return ret; if (st->chip_info->reset) st->chip_info->reset(st); return devm_iio_device_register(&spi->dev, indio_dev); } static const struct spi_device_id ad7476_id[] = { { "ad7091", ID_AD7091 }, { "ad7091r", ID_AD7091R }, { "ad7273", ID_AD7273 }, { "ad7274", ID_AD7274 }, { "ad7276", ID_AD7276}, { "ad7277", ID_AD7277 }, { "ad7278", ID_AD7278 }, { "ad7466", ID_AD7466 }, { "ad7467", ID_AD7467 }, { "ad7468", ID_AD7468 }, { "ad7475", ID_AD7475 }, { "ad7476", ID_AD7466 }, { "ad7476a", ID_AD7466 }, { "ad7477", ID_AD7467 }, { "ad7477a", ID_AD7467 }, { "ad7478", ID_AD7468 }, { "ad7478a", ID_AD7468 }, { "ad7495", ID_AD7495 }, { "ad7910", ID_AD7467 }, { "ad7920", ID_AD7466 }, { "ad7940", ID_AD7940 }, { "adc081s", ID_ADC081S }, { "adc101s", ID_ADC101S }, { "adc121s", ID_ADC121S }, { "ads7866", ID_ADS7866 }, { "ads7867", ID_ADS7867 }, { "ads7868", ID_ADS7868 }, { "ltc2314-14", ID_LTC2314_14 }, { } }; MODULE_DEVICE_TABLE(spi, ad7476_id); static struct spi_driver ad7476_driver = { .driver = { .name = "ad7476", }, .probe = ad7476_probe, .id_table = ad7476_id, }; module_spi_driver(ad7476_driver); MODULE_AUTHOR("Michael Hennerich "); MODULE_DESCRIPTION("Analog Devices AD7476 and similar 1-channel ADCs"); MODULE_LICENSE("GPL v2");