diff options
Diffstat (limited to 'drivers/iio/adc/ti-adc161s626.c')
| -rw-r--r-- | drivers/iio/adc/ti-adc161s626.c | 248 |
1 files changed, 248 insertions, 0 deletions
diff --git a/drivers/iio/adc/ti-adc161s626.c b/drivers/iio/adc/ti-adc161s626.c new file mode 100644 index 000000000000..f94b69f9c288 --- /dev/null +++ b/drivers/iio/adc/ti-adc161s626.c @@ -0,0 +1,248 @@ +/* + * ti-adc161s626.c - Texas Instruments ADC161S626 1-channel differential ADC + * + * ADC Devices Supported: + * adc141s626 - 14-bit ADC + * adc161s626 - 16-bit ADC + * + * Copyright (C) 2016 Matt Ranostay <mranostay@gmail.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <linux/module.h> +#include <linux/init.h> +#include <linux/err.h> +#include <linux/spi/spi.h> +#include <linux/iio/iio.h> +#include <linux/iio/trigger.h> +#include <linux/iio/buffer.h> +#include <linux/iio/trigger_consumer.h> +#include <linux/iio/triggered_buffer.h> + +#define TI_ADC_DRV_NAME "ti-adc161s626" + +enum { + TI_ADC141S626, + TI_ADC161S626, +}; + +static const struct iio_chan_spec ti_adc141s626_channels[] = { + { + .type = IIO_VOLTAGE, + .channel = 0, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), + .scan_index = 0, + .scan_type = { + .sign = 's', + .realbits = 14, + .storagebits = 16, + }, + }, + IIO_CHAN_SOFT_TIMESTAMP(1), +}; + +static const struct iio_chan_spec ti_adc161s626_channels[] = { + { + .type = IIO_VOLTAGE, + .channel = 0, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), + .scan_index = 0, + .scan_type = { + .sign = 's', + .realbits = 16, + .storagebits = 16, + }, + }, + IIO_CHAN_SOFT_TIMESTAMP(1), +}; + +struct ti_adc_data { + struct iio_dev *indio_dev; + struct spi_device *spi; + u8 read_size; + u8 shift; + + u8 buffer[16] ____cacheline_aligned; +}; + +static int ti_adc_read_measurement(struct ti_adc_data *data, + struct iio_chan_spec const *chan, int *val) +{ + int ret; + + switch (data->read_size) { + case 2: { + __be16 buf; + + ret = spi_read(data->spi, (void *) &buf, 2); + if (ret) + return ret; + + *val = be16_to_cpu(buf); + break; + } + case 3: { + __be32 buf; + + ret = spi_read(data->spi, (void *) &buf, 3); + if (ret) + return ret; + + *val = be32_to_cpu(buf) >> 8; + break; + } + default: + return -EINVAL; + } + + *val = sign_extend32(*val >> data->shift, chan->scan_type.realbits - 1); + + return 0; +} + +static irqreturn_t ti_adc_trigger_handler(int irq, void *private) +{ + struct iio_poll_func *pf = private; + struct iio_dev *indio_dev = pf->indio_dev; + struct ti_adc_data *data = iio_priv(indio_dev); + int ret; + + ret = ti_adc_read_measurement(data, &indio_dev->channels[0], + (int *) &data->buffer); + if (!ret) + iio_push_to_buffers_with_timestamp(indio_dev, + data->buffer, + iio_get_time_ns(indio_dev)); + + iio_trigger_notify_done(indio_dev->trig); + + return IRQ_HANDLED; +} + +static int ti_adc_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, long mask) +{ + struct ti_adc_data *data = iio_priv(indio_dev); + int ret; + + if (mask != IIO_CHAN_INFO_RAW) + return -EINVAL; + + ret = iio_device_claim_direct_mode(indio_dev); + if (ret) + return ret; + + ret = ti_adc_read_measurement(data, chan, val); + iio_device_release_direct_mode(indio_dev); + + if (!ret) + return IIO_VAL_INT; + + return 0; +} + +static const struct iio_info ti_adc_info = { + .driver_module = THIS_MODULE, + .read_raw = ti_adc_read_raw, +}; + +static int ti_adc_probe(struct spi_device *spi) +{ + struct iio_dev *indio_dev; + struct ti_adc_data *data; + int ret; + + indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*data)); + if (!indio_dev) + return -ENOMEM; + + indio_dev->info = &ti_adc_info; + indio_dev->dev.parent = &spi->dev; + indio_dev->dev.of_node = spi->dev.of_node; + indio_dev->name = TI_ADC_DRV_NAME; + indio_dev->modes = INDIO_DIRECT_MODE; + spi_set_drvdata(spi, indio_dev); + + data = iio_priv(indio_dev); + data->spi = spi; + + switch (spi_get_device_id(spi)->driver_data) { + case TI_ADC141S626: + indio_dev->channels = ti_adc141s626_channels; + indio_dev->num_channels = ARRAY_SIZE(ti_adc141s626_channels); + data->shift = 0; + data->read_size = 2; + break; + case TI_ADC161S626: + indio_dev->channels = ti_adc161s626_channels; + indio_dev->num_channels = ARRAY_SIZE(ti_adc161s626_channels); + data->shift = 6; + data->read_size = 3; + break; + } + + ret = iio_triggered_buffer_setup(indio_dev, NULL, + ti_adc_trigger_handler, NULL); + if (ret) + return ret; + + ret = iio_device_register(indio_dev); + if (ret) + goto error_unreg_buffer; + + return 0; + +error_unreg_buffer: + iio_triggered_buffer_cleanup(indio_dev); + + return ret; +} + +static int ti_adc_remove(struct spi_device *spi) +{ + struct iio_dev *indio_dev = spi_get_drvdata(spi); + + iio_device_unregister(indio_dev); + iio_triggered_buffer_cleanup(indio_dev); + + return 0; +} + +static const struct of_device_id ti_adc_dt_ids[] = { + { .compatible = "ti,adc141s626", }, + { .compatible = "ti,adc161s626", }, + {} +}; +MODULE_DEVICE_TABLE(of, ti_adc_dt_ids); + +static const struct spi_device_id ti_adc_id[] = { + {"adc141s626", TI_ADC141S626}, + {"adc161s626", TI_ADC161S626}, + {}, +}; +MODULE_DEVICE_TABLE(spi, ti_adc_id); + +static struct spi_driver ti_adc_driver = { + .driver = { + .name = TI_ADC_DRV_NAME, + .of_match_table = of_match_ptr(ti_adc_dt_ids), + }, + .probe = ti_adc_probe, + .remove = ti_adc_remove, + .id_table = ti_adc_id, +}; +module_spi_driver(ti_adc_driver); + +MODULE_AUTHOR("Matt Ranostay <mranostay@gmail.com>"); +MODULE_DESCRIPTION("Texas Instruments ADC1x1S 1-channel differential ADC"); +MODULE_LICENSE("GPL"); |