// SPDX-License-Identifier: GPL-2.0-only /* * TI ADC108S102 SPI ADC driver * * Copyright (c) 2013-2015 Intel Corporation. * Copyright (c) 2017 Siemens AG * * This IIO device driver is designed to work with the following * analog to digital converters from Texas Instruments: * ADC108S102 * ADC128S102 * The communication with ADC chip is via the SPI bus (mode 3). */ #include #include #include #include #include #include #include #include #include #include #include /* * In case of ACPI, we use the hard-wired 5000 mV of the Galileo and IOT2000 * boards as default for the reference pin VA. Device tree users encode that * via the vref-supply regulator. */ #define ADC108S102_VA_MV_ACPI_DEFAULT 5000 /* * Defining the ADC resolution being 12 bits, we can use the same driver for * both ADC108S102 (10 bits resolution) and ADC128S102 (12 bits resolution) * chips. The ADC108S102 effectively returns a 12-bit result with the 2 * least-significant bits unset. */ #define ADC108S102_BITS 12 #define ADC108S102_MAX_CHANNELS 8 /* * 16-bit SPI command format: * [15:14] Ignored * [13:11] 3-bit channel address * [10:0] Ignored */ #define ADC108S102_CMD(ch) ((u16)(ch) << 11) /* * 16-bit SPI response format: * [15:12] Zeros * [11:0] 12-bit ADC sample (for ADC108S102, [1:0] will always be 0). */ #define ADC108S102_RES_DATA(res) ((u16)res & GENMASK(11, 0)) struct adc108s102_state { struct spi_device *spi; struct regulator *reg; u32 va_millivolt; /* SPI transfer used by triggered buffer handler*/ struct spi_transfer ring_xfer; /* SPI transfer used by direct scan */ struct spi_transfer scan_single_xfer; /* SPI message used by ring_xfer SPI transfer */ struct spi_message ring_msg; /* SPI message used by scan_single_xfer SPI transfer */ struct spi_message scan_single_msg; /* * SPI message buffers: * tx_buf: |C0|C1|C2|C3|C4|C5|C6|C7|XX| * rx_buf: |XX|R0|R1|R2|R3|R4|R5|R6|R7|tt|tt|tt|tt| * * tx_buf: 8 channel read commands, plus 1 dummy command * rx_buf: 1 dummy response, 8 channel responses, plus 64-bit timestamp */ __be16 rx_buf[13] ____cacheline_aligned; __be16 tx_buf[9] ____cacheline_aligned; }; #define ADC108S102_V_CHAN(index) \ { \ .type = IIO_VOLTAGE, \ .indexed = 1, \ .channel = index, \ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ BIT(IIO_CHAN_INFO_SCALE), \ .address = index, \ .scan_index = index, \ .scan_type = { \ .sign = 'u', \ .realbits = ADC108S102_BITS, \ .storagebits = 16, \ .endianness = IIO_BE, \ }, \ } static const struct iio_chan_spec adc108s102_channels[] = { ADC108S102_V_CHAN(0), ADC108S102_V_CHAN(1), ADC108S102_V_CHAN(2), ADC108S102_V_CHAN(3), ADC108S102_V_CHAN(4), ADC108S102_V_CHAN(5), ADC108S102_V_CHAN(6), ADC108S102_V_CHAN(7), IIO_CHAN_SOFT_TIMESTAMP(8), }; static int adc108s102_update_scan_mode(struct iio_dev *indio_dev, unsigned long const *active_scan_mask) { struct adc108s102_state *st = iio_priv(indio_dev); unsigned int bit, cmds; /* * Fill in the first x shorts of tx_buf with the number of channels * enabled for sampling by the triggered buffer. */ cmds = 0; for_each_set_bit(bit, active_scan_mask, ADC108S102_MAX_CHANNELS) st->tx_buf[cmds++] = cpu_to_be16(ADC108S102_CMD(bit)); /* One dummy command added, to clock in the last response */ st->tx_buf[cmds++] = 0x00; /* build SPI ring message */ st->ring_xfer.tx_buf = &st->tx_buf[0]; st->ring_xfer.rx_buf = &st->rx_buf[0]; st->ring_xfer.len = cmds * sizeof(st->tx_buf[0]); spi_message_init_with_transfers(&st->ring_msg, &st->ring_xfer, 1); return 0; } static irqreturn_t adc108s102_trigger_handler(int irq, void *p) { struct iio_poll_func *pf = p; struct iio_dev *indio_dev = pf->indio_dev; struct adc108s102_state *st = iio_priv(indio_dev); int ret; ret = spi_sync(st->spi, &st->ring_msg); if (ret < 0) goto out_notify; /* Skip the dummy response in the first slot */ iio_push_to_buffers_with_timestamp(indio_dev, (u8 *)&st->rx_buf[1], iio_get_time_ns(indio_dev)); out_notify: iio_trigger_notify_done(indio_dev->trig); return IRQ_HANDLED; } static int adc108s102_scan_direct(struct adc108s102_state *st, unsigned int ch) { int ret; st->tx_buf[0] = cpu_to_be16(ADC108S102_CMD(ch)); ret = spi_sync(st->spi, &st->scan_single_msg); if (ret) return ret; /* Skip the dummy response in the first slot */ return be16_to_cpu(st->rx_buf[1]); } static int adc108s102_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val, int *val2, long m) { struct adc108s102_state *st = iio_priv(indio_dev); int ret; switch (m) { case IIO_CHAN_INFO_RAW: ret = iio_device_claim_direct_mode(indio_dev); if (ret) return ret; ret = adc108s102_scan_direct(st, chan->address); iio_device_release_direct_mode(indio_dev); if (ret < 0) return ret; *val = ADC108S102_RES_DATA(ret); return IIO_VAL_INT; case IIO_CHAN_INFO_SCALE: if (chan->type != IIO_VOLTAGE) break; *val = st->va_millivolt; *val2 = chan->scan_type.realbits; return IIO_VAL_FRACTIONAL_LOG2; default: break; } return -EINVAL; } static const struct iio_info adc108s102_info = { .read_raw = &adc108s102_read_raw, .update_scan_mode = &adc108s102_update_scan_mode, }; static int adc108s102_probe(struct spi_device *spi) { struct adc108s102_state *st; struct iio_dev *indio_dev; int ret; indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st)); if (!indio_dev) return -ENOMEM; st = iio_priv(indio_dev); if (ACPI_COMPANION(&spi->dev)) { st->va_millivolt = ADC108S102_VA_MV_ACPI_DEFAULT; } else { st->reg = devm_regulator_get(&spi->dev, "vref"); if (IS_ERR(st->reg)) return PTR_ERR(st->reg); ret = regulator_enable(st->reg); if (ret < 0) { dev_err(&spi->dev, "Cannot enable vref regulator\n"); return ret; } ret = regulator_get_voltage(st->reg); if (ret < 0) { dev_err(&spi->dev, "vref get voltage failed\n"); return ret; } st->va_millivolt = ret / 1000; } spi_set_drvdata(spi, indio_dev); st->spi = spi; indio_dev->name = spi->modalias; indio_dev->dev.parent = &spi->dev; indio_dev->modes = INDIO_DIRECT_MODE; indio_dev->channels = adc108s102_channels; indio_dev->num_channels = ARRAY_SIZE(adc108s102_channels); indio_dev->info = &adc108s102_info; /* Setup default message */ st->scan_single_xfer.tx_buf = st->tx_buf; st->scan_single_xfer.rx_buf = st->rx_buf; st->scan_single_xfer.len = 2 * sizeof(st->tx_buf[0]); spi_message_init_with_transfers(&st->scan_single_msg, &st->scan_single_xfer, 1); ret = iio_triggered_buffer_setup(indio_dev, NULL, &adc108s102_trigger_handler, NULL); if (ret) goto error_disable_reg; ret = iio_device_register(indio_dev); if (ret) { dev_err(&spi->dev, "Failed to register IIO device\n"); goto error_cleanup_triggered_buffer; } return 0; error_cleanup_triggered_buffer: iio_triggered_buffer_cleanup(indio_dev); error_disable_reg: regulator_disable(st->reg); return ret; } static int adc108s102_remove(struct spi_device *spi) { struct iio_dev *indio_dev = spi_get_drvdata(spi); struct adc108s102_state *st = iio_priv(indio_dev); iio_device_unregister(indio_dev); iio_triggered_buffer_cleanup(indio_dev); regulator_disable(st->reg); return 0; } #ifdef CONFIG_OF static const struct of_device_id adc108s102_of_match[] = { { .compatible = "ti,adc108s102" }, { } }; MODULE_DEVICE_TABLE(of, adc108s102_of_match); #endif #ifdef CONFIG_ACPI static const struct acpi_device_id adc108s102_acpi_ids[] = { { "INT3495", 0 }, { } }; MODULE_DEVICE_TABLE(acpi, adc108s102_acpi_ids); #endif static const struct spi_device_id adc108s102_id[] = { { "adc108s102", 0 }, { } }; MODULE_DEVICE_TABLE(spi, adc108s102_id); static struct spi_driver adc108s102_driver = { .driver = { .name = "adc108s102", .of_match_table = of_match_ptr(adc108s102_of_match), .acpi_match_table = ACPI_PTR(adc108s102_acpi_ids), }, .probe = adc108s102_probe, .remove = adc108s102_remove, .id_table = adc108s102_id, }; module_spi_driver(adc108s102_driver); MODULE_AUTHOR("Bogdan Pricop "); MODULE_DESCRIPTION("Texas Instruments ADC108S102 and ADC128S102 driver"); MODULE_LICENSE("GPL v2");