File-copy from v4.4.100
This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Please refer to that tree for all history prior to this point.
Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/drivers/iio/adc/ti-adc128s052.c b/drivers/iio/adc/ti-adc128s052.c
new file mode 100644
index 0000000..ff6f7f6
--- /dev/null
+++ b/drivers/iio/adc/ti-adc128s052.c
@@ -0,0 +1,204 @@
+/*
+ * Copyright (C) 2014 Angelo Compagnucci <angelo.compagnucci@gmail.com>
+ *
+ * Driver for Texas Instruments' ADC128S052 and ADC122S021 ADC chip.
+ * Datasheets can be found here:
+ * http://www.ti.com/lit/ds/symlink/adc128s052.pdf
+ * http://www.ti.com/lit/ds/symlink/adc122s021.pdf
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/err.h>
+#include <linux/spi/spi.h>
+#include <linux/module.h>
+#include <linux/iio/iio.h>
+#include <linux/regulator/consumer.h>
+
+struct adc128_configuration {
+ const struct iio_chan_spec *channels;
+ u8 num_channels;
+};
+
+struct adc128 {
+ struct spi_device *spi;
+
+ struct regulator *reg;
+ struct mutex lock;
+
+ u8 buffer[2] ____cacheline_aligned;
+};
+
+static int adc128_adc_conversion(struct adc128 *adc, u8 channel)
+{
+ int ret;
+
+ mutex_lock(&adc->lock);
+
+ adc->buffer[0] = channel << 3;
+ adc->buffer[1] = 0;
+
+ ret = spi_write(adc->spi, &adc->buffer, 2);
+ if (ret < 0) {
+ mutex_unlock(&adc->lock);
+ return ret;
+ }
+
+ ret = spi_read(adc->spi, &adc->buffer, 2);
+
+ mutex_unlock(&adc->lock);
+
+ if (ret < 0)
+ return ret;
+
+ return ((adc->buffer[0] << 8 | adc->buffer[1]) & 0xFFF);
+}
+
+static int adc128_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *channel, int *val,
+ int *val2, long mask)
+{
+ struct adc128 *adc = iio_priv(indio_dev);
+ int ret;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+
+ ret = adc128_adc_conversion(adc, channel->channel);
+ if (ret < 0)
+ return ret;
+
+ *val = ret;
+ return IIO_VAL_INT;
+
+ case IIO_CHAN_INFO_SCALE:
+
+ ret = regulator_get_voltage(adc->reg);
+ if (ret < 0)
+ return ret;
+
+ *val = ret / 1000;
+ *val2 = 12;
+ return IIO_VAL_FRACTIONAL_LOG2;
+
+ default:
+ return -EINVAL;
+ }
+
+}
+
+#define ADC128_VOLTAGE_CHANNEL(num) \
+ { \
+ .type = IIO_VOLTAGE, \
+ .indexed = 1, \
+ .channel = (num), \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \
+ }
+
+static const struct iio_chan_spec adc128s052_channels[] = {
+ ADC128_VOLTAGE_CHANNEL(0),
+ ADC128_VOLTAGE_CHANNEL(1),
+ ADC128_VOLTAGE_CHANNEL(2),
+ ADC128_VOLTAGE_CHANNEL(3),
+ ADC128_VOLTAGE_CHANNEL(4),
+ ADC128_VOLTAGE_CHANNEL(5),
+ ADC128_VOLTAGE_CHANNEL(6),
+ ADC128_VOLTAGE_CHANNEL(7),
+};
+
+static const struct iio_chan_spec adc122s021_channels[] = {
+ ADC128_VOLTAGE_CHANNEL(0),
+ ADC128_VOLTAGE_CHANNEL(1),
+};
+
+static const struct adc128_configuration adc128_config[] = {
+ { adc128s052_channels, ARRAY_SIZE(adc128s052_channels) },
+ { adc122s021_channels, ARRAY_SIZE(adc122s021_channels) },
+};
+
+static const struct iio_info adc128_info = {
+ .read_raw = adc128_read_raw,
+ .driver_module = THIS_MODULE,
+};
+
+static int adc128_probe(struct spi_device *spi)
+{
+ struct iio_dev *indio_dev;
+ struct adc128 *adc;
+ int config = spi_get_device_id(spi)->driver_data;
+ int ret;
+
+ indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*adc));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ adc = iio_priv(indio_dev);
+ adc->spi = spi;
+
+ spi_set_drvdata(spi, indio_dev);
+
+ indio_dev->dev.parent = &spi->dev;
+ indio_dev->name = spi_get_device_id(spi)->name;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->info = &adc128_info;
+
+ indio_dev->channels = adc128_config[config].channels;
+ indio_dev->num_channels = adc128_config[config].num_channels;
+
+ adc->reg = devm_regulator_get(&spi->dev, "vref");
+ if (IS_ERR(adc->reg))
+ return PTR_ERR(adc->reg);
+
+ ret = regulator_enable(adc->reg);
+ if (ret < 0)
+ return ret;
+
+ mutex_init(&adc->lock);
+
+ ret = iio_device_register(indio_dev);
+
+ return ret;
+}
+
+static int adc128_remove(struct spi_device *spi)
+{
+ struct iio_dev *indio_dev = spi_get_drvdata(spi);
+ struct adc128 *adc = iio_priv(indio_dev);
+
+ iio_device_unregister(indio_dev);
+ regulator_disable(adc->reg);
+
+ return 0;
+}
+
+static const struct of_device_id adc128_of_match[] = {
+ { .compatible = "ti,adc128s052", },
+ { .compatible = "ti,adc122s021", },
+ { /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, adc128_of_match);
+
+static const struct spi_device_id adc128_id[] = {
+ { "adc128s052", 0}, /* index into adc128_config */
+ { "adc122s021", 1},
+ { }
+};
+MODULE_DEVICE_TABLE(spi, adc128_id);
+
+static struct spi_driver adc128_driver = {
+ .driver = {
+ .name = "adc128s052",
+ .of_match_table = of_match_ptr(adc128_of_match),
+ },
+ .probe = adc128_probe,
+ .remove = adc128_remove,
+ .id_table = adc128_id,
+};
+module_spi_driver(adc128_driver);
+
+MODULE_AUTHOR("Angelo Compagnucci <angelo.compagnucci@gmail.com>");
+MODULE_DESCRIPTION("Texas Instruments ADC128S052");
+MODULE_LICENSE("GPL v2");