--- /dev/null
+/*
+ * 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");
projects / cascardo / linux.git / commitdiff