From: Mårten Lindahl <martenli@xxxxxxxx>
This adds support for the Texas Instruments ADC084S021 ADC chip.
Signed-off-by: Mårten Lindahl <martenli@xxxxxxxx>
---
.../devicetree/bindings/iio/adc/ti-adc084s021.txt | 25 ++
drivers/iio/adc/Kconfig | 12 +
drivers/iio/adc/Makefile | 1 +
drivers/iio/adc/ti-adc084s021.c | 342 +++++++++++++++++++++
4 files changed, 380 insertions(+)
create mode 100644 Documentation/devicetree/bindings/iio/adc/ti-adc084s021.txt
create mode 100644 drivers/iio/adc/ti-adc084s021.c
diff --git a/Documentation/devicetree/bindings/iio/adc/ti-adc084s021.txt b/Documentation/devicetree/bindings/iio/adc/ti-adc084s021.txt
new file mode 100644
index 0000000..921eb46
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/adc/ti-adc084s021.txt
@@ -0,0 +1,25 @@
+* Texas Instruments' ADC084S021
+
+Required properties:
+ - compatible : Must be "ti,adc084s021"
+ - reg : SPI chip select number for the device
+ - vref-supply : The regulator supply for ADC reference voltage
+ - spi-max-frequency : Definition as per Documentation/devicetree/bindings/spi/spi-bus.txt
+
+Optional properties:
+ - spi-cpol : SPI inverse clock polarity, as per spi-bus bindings
+ - spi-cpha : SPI shifted clock phase (CPHA), as per spi-bus bindings
+ - spi-cs-high : SPI chip select active high, as per spi-bus bindings
+
+
+Example:
+adc@0 {
+ compatible = "ti,adc084s021";
+ reg = <0>;
+ vref-supply = <&adc_vref>;
+ spi-cpol;
+ spi-cpha;
+ spi-cs-high;
+ spi-max-frequency = <16000000>;
+ pl022,com-mode = <0x2>; /* DMA */
+};
diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index dedae7a..13141e5 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -560,6 +560,18 @@ config TI_ADC0832
This driver can also be built as a module. If so, the module will be
called ti-adc0832.
+config TI_ADC084S021
+ tristate "Texas Instruments ADC084S021"
+ depends on SPI
+ select IIO_BUFFER
+ select IIO_TRIGGERED_BUFFER
+ help
+ If you say yes here you get support for Texas Instruments ADC084S021
+ chips.
+
+ This driver can also be built as a module. If so, the module will be
+ called ti-adc084s021.
+
config TI_ADC12138
tristate "Texas Instruments ADC12130/ADC12132/ADC12138"
depends on SPI
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index d001262..b1a6158 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -51,6 +51,7 @@ obj-$(CONFIG_STM32_ADC_CORE) += stm32-adc-core.o
obj-$(CONFIG_STM32_ADC) += stm32-adc.o
obj-$(CONFIG_TI_ADC081C) += ti-adc081c.o
obj-$(CONFIG_TI_ADC0832) += ti-adc0832.o
+obj-$(CONFIG_TI_ADC084S021) += ti-adc084s021.o
obj-$(CONFIG_TI_ADC12138) += ti-adc12138.o
obj-$(CONFIG_TI_ADC128S052) += ti-adc128s052.o
obj-$(CONFIG_TI_ADC161S626) += ti-adc161s626.o
diff --git a/drivers/iio/adc/ti-adc084s021.c b/drivers/iio/adc/ti-adc084s021.c
new file mode 100644
index 0000000..4f33b91
--- /dev/null
+++ b/drivers/iio/adc/ti-adc084s021.c
@@ -0,0 +1,342 @@
+/**
+ * Copyright (C) 2017 Axis Communications AB
+ *
+ * Driver for Texas Instruments' ADC084S021 ADC chip.
+ * Datasheets can be found here:
+ * http://www.ti.com/lit/ds/symlink/adc084s021.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/interrupt.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/events.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/regulator/consumer.h>
+
+#define MODULE_NAME "adc084s021"
+#define DRIVER_VERSION "1.0"
+#define ADC_RESOLUTION 8
+#define ADC_N_CHANNELS 4
+
+struct adc084s021_configuration {
+ const struct iio_chan_spec *channels;
+ u8 num_channels;
+};
+
+struct adc084s021 {
+ struct spi_device *spi;
+ struct spi_message message;
+ struct spi_transfer spi_trans[2];
+ struct regulator *reg;
+ struct mutex lock;
+ /*
+ * DMA (thus cache coherency maintenance) requires the
+ * transfer buffers to live in their own cache lines.
+ */
+ union {
+ u8 tx_buf[2];
+ u8 rx_buf[2];
+ } ____cacheline_aligned;
+ u8 cur_adc_values[ADC_N_CHANNELS];
+};
+
+/**
+ * Event triggered when value changes on a channel
+ */
+static const struct iio_event_spec adc084s021_event = {
+ .type = IIO_EV_TYPE_CHANGE,
+ .dir = IIO_EV_DIR_NONE,
+};
+
+/**
+ * Channel specification
+ */
+#define ADC084S021_VOLTAGE_CHANNEL(num) \
+ { \
+ .type = IIO_VOLTAGE, \
+ .channel = (num), \
+ .address = (num << 3), \
+ .indexed = 1, \
+ .scan_index = num, \
+ .scan_type = { \
+ .sign = 'u', \
+ .realbits = 8, \
+ .storagebits = 32, \
+ .shift = 24 - ((num << 3)), \
+ }, \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+ .event_spec = &adc084s021_event, \
+ .num_event_specs = 1, \
+ }
+
+static const struct iio_chan_spec adc084s021_channels[] = {
+ ADC084S021_VOLTAGE_CHANNEL(0),
+ ADC084S021_VOLTAGE_CHANNEL(1),
+ ADC084S021_VOLTAGE_CHANNEL(2),
+ ADC084S021_VOLTAGE_CHANNEL(3),
+ IIO_CHAN_SOFT_TIMESTAMP(4),
+};
+
+static const struct adc084s021_configuration adc084s021_config[] = {
+ { adc084s021_channels, ARRAY_SIZE(adc084s021_channels) },
+};
+
+/**
+ * Read an ADC channel and return its value.
+ *
+ * @adc: The ADC SPI data.
+ * @channel: The IIO channel data structure.
+ */
+static int adc084s021_adc_conversion(struct adc084s021 *adc,
+ struct iio_chan_spec const *channel)
+{
+ u16 value;
+ int ret;
+
+ mutex_lock(&adc->lock);
+ adc->tx_buf[0] = channel->address;
+
+ /* Do the transfer */
+ ret = spi_sync(adc->spi, &adc->message);
+
+ if (ret < 0) {
+ mutex_unlock(&adc->lock);
+ return ret;
+ }
+
+ value = (adc->rx_buf[0] << 4) | (adc->rx_buf[1] >> 4);
+ mutex_unlock(&adc->lock);
+
+ dev_dbg(&adc->spi->dev, "value 0x%02X on channel %d\n",
+ value, channel->channel);
+ return value;
+}
+
+/**
+ * Make a readout of requested IIO channel info.
+ *
+ * @indio_dev: The industrial I/O device.
+ * @channel: The IIO channel data structure.
+ * @val: First element of value (integer).
+ * @val2: Second element of value (fractional).
+ * @mask: The info_mask to read.
+ */
+static int adc084s021_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *channel, int *val,
+ int *val2, long mask)
+{
+ struct adc084s021 *adc = iio_priv(indio_dev);
+ int retval;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ retval = adc084s021_adc_conversion(adc, channel);
+ if (retval < 0)
+ return retval;
+
+ *val = retval;
+ return IIO_VAL_INT;
+
+ default:
+ return -EINVAL;
+ }
+}
+
+/**
+ * Read enabled ADC channels and push data to the buffer.
+ *
+ * @irq: The interrupt number (not used).
+ * @pollfunc: Pointer to the poll func.
+ */
+static irqreturn_t adc084s021_trigger_handler(int irq, void *pollfunc)
+{
+ struct iio_poll_func *pf = pollfunc;
+ struct iio_dev *indio_dev = pf->indio_dev;
+ struct adc084s021 *adc = iio_priv(indio_dev);
+ u8 *data;
+ s64 timestamp;
+ int value, scan_index;
+
+ data = kzalloc(indio_dev->scan_bytes, GFP_KERNEL);
+ if (!data) {
+ iio_trigger_notify_done(indio_dev->trig);
+ return IRQ_NONE;
+ }
+
+ timestamp = iio_get_time_ns(indio_dev);
+
+ for_each_set_bit(scan_index, indio_dev->active_scan_mask,
+ indio_dev->masklength) {
+ const struct iio_chan_spec *channel =
+ &indio_dev->channels[scan_index];
+ value = adc084s021_adc_conversion(adc, channel);
+ data[scan_index] = value;
+
+ /*
+ * Compare read data to previous read. If it differs send
+ * event notification for affected channel.
+ */
+ if (adc->cur_adc_values[scan_index] != (u8)value) {
+ adc->cur_adc_values[scan_index] = (u8)value;
+ iio_push_event(indio_dev,
+ IIO_EVENT_CODE(IIO_VOLTAGE, 0,
+ IIO_NO_MOD, IIO_EV_DIR_NONE,
+ IIO_EV_TYPE_CHANGE,
+ channel->channel, 0, 0),
+ timestamp);
+ dev_dbg(&indio_dev->dev,
+ "new value on ch%d: 0x%02X (ts %llu)\n",
+ channel->channel, value, timestamp);
+ }
+ }
+
+ iio_push_to_buffers_with_timestamp(indio_dev, data, timestamp);
+ iio_trigger_notify_done(indio_dev->trig);
+ kfree(data);
+ return IRQ_HANDLED;
+}
+
+static const struct iio_info adc084s021_info = {
+ .read_raw = adc084s021_read_raw,
+ .driver_module = THIS_MODULE,
+};
+
+/**
+ * Create and register ADC IIO device for SPI.
+ */
+static int adc084s021_probe(struct spi_device *spi)
+{
+ struct iio_dev *indio_dev;
+ struct adc084s021 *adc;
+ int config = spi_get_device_id(spi)->driver_data;
+ int retval;
+
+ /* Allocate an Industrial I/O device */
+ indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*adc));
+ if (!indio_dev) {
+ dev_err(&spi->dev, "Failed to allocate IIO device\n");
+ return -ENOMEM;
+ }
+
+ adc = iio_priv(indio_dev);
+ adc->spi = spi;
+ spi->bits_per_word = ADC_RESOLUTION;
+
+ /* Update the SPI device with config and connect the iio dev */
+ retval = spi_setup(spi);
+ if (retval) {
+ dev_err(&spi->dev, "Failed to update SPI device\n");
+ return retval;
+ }
+ spi_set_drvdata(spi, indio_dev);
+
+ /* Initiate the Industrial I/O device */
+ indio_dev->dev.parent = &spi->dev;
+ indio_dev->dev.of_node = spi->dev.of_node;
+ indio_dev->name = spi_get_device_id(spi)->name;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->info = &adc084s021_info;
+ indio_dev->channels = adc084s021_config[config].channels;
+ indio_dev->num_channels = adc084s021_config[config].num_channels;
+
+ /* Create SPI transfer for channel reads */
+ adc->spi_trans[0].tx_buf = &adc->tx_buf[0];
+ adc->spi_trans[0].len = 2;
+ adc->spi_trans[0].speed_hz = spi->max_speed_hz;
+ adc->spi_trans[0].bits_per_word = spi->bits_per_word;
+ adc->spi_trans[1].rx_buf = &adc->rx_buf[0];
+ adc->spi_trans[1].len = 2;
+ adc->spi_trans[1].speed_hz = spi->max_speed_hz;
+ adc->spi_trans[1].bits_per_word = spi->bits_per_word;
+
+ /* Setup SPI message for channel reads */
+ spi_message_init(&adc->message);
+ spi_message_add_tail(&adc->spi_trans[0], &adc->message);
+ spi_message_add_tail(&adc->spi_trans[1], &adc->message);
+
+ adc->reg = devm_regulator_get(&spi->dev, "vref");
+ if (IS_ERR(adc->reg))
+ return PTR_ERR(adc->reg);
+
+ retval = regulator_enable(adc->reg);
+ if (retval < 0)
+ return retval;
+
+ mutex_init(&adc->lock);
+
+ /* Setup triggered buffer with pollfunction */
+ retval = iio_triggered_buffer_setup(indio_dev, NULL,
+ adc084s021_trigger_handler, NULL);
+ if (retval) {
+ dev_err(&spi->dev, "Failed to setup triggered buffer\n");
+ goto buffer_setup_failed;
+ }
+
+ retval = iio_device_register(indio_dev);
+ if (retval) {
+ dev_err(&spi->dev, "Failed to register IIO device\n");
+ goto device_register_failed;
+ }
+
+ dev_info(&spi->dev, "probed!\n");
+ return 0;
+
+device_register_failed:
+ iio_triggered_buffer_cleanup(indio_dev);
+buffer_setup_failed:
+ regulator_disable(adc->reg);
+ return retval;
+}
+
+/**
+ * Unregister ADC IIO device for SPI.
+ */
+static int adc084s021_remove(struct spi_device *spi)
+{
+ struct iio_dev *indio_dev = spi_get_drvdata(spi);
+ struct adc084s021 *adc = iio_priv(indio_dev);
+
+ iio_device_unregister(indio_dev);
+ iio_triggered_buffer_cleanup(indio_dev);
+ regulator_disable(adc->reg);
+ return 0;
+}
+
+static const struct of_device_id adc084s021_of_match[] = {
+ { .compatible = "ti,adc084s021", },
+ {},
+};
+
+MODULE_DEVICE_TABLE(of, adc084s021_of_match);
+
+static const struct spi_device_id adc084s021_id[] = {
+ { MODULE_NAME, 0},
+ {}
+};
+
+MODULE_DEVICE_TABLE(spi, adc084s021_id);
+
+static struct spi_driver adc084s021_driver = {
+ .driver = {
+ .name = MODULE_NAME,
+ .of_match_table = of_match_ptr(adc084s021_of_match),
+ },
+ .probe = adc084s021_probe,
+ .remove = adc084s021_remove,
+ .id_table = adc084s021_id,
+};
+
+module_spi_driver(adc084s021_driver);
+
+MODULE_AUTHOR("Mårten Lindahl <martenli@xxxxxxxx>");
+MODULE_DESCRIPTION("Texas Instruments ADC084S021");
+MODULE_LICENSE("GPL v2");
+MODULE_VERSION(DRIVER_VERSION);
--
2.1.4
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