From: Gregory CLEMENT <gregory.clement@bootlin.com>
To: Jonathan Cameron <jic23@kernel.org>,
Hartmut Knaack <knaack.h@gmx.de>,
Lars-Peter Clausen <lars@metafoo.de>,
Peter Meerwald-Stadler <pmeerw@pmeerw.net>,
linux-iio@vger.kernel.org
Cc: Rob Herring <robh+dt@kernel.org>,
devicetree@vger.kernel.org,
Thomas Petazzoni <thomas.petazzoni@bootlin.com>,
linux-arm-kernel@lists.infradead.org,
Alexandre Belloni <alexandre.belloni@bootlin.com>,
Gregory CLEMENT <gregory.clement@bootlin.com>
Subject: [PATCH v2 2/2] iio: adc: Add driver for the TI ADS8344 A/DC chips
Date: Fri, 22 Mar 2019 12:11:08 +0100 [thread overview]
Message-ID: <20190322111108.19383-3-gregory.clement@bootlin.com> (raw)
In-Reply-To: <20190322111108.19383-1-gregory.clement@bootlin.com>
This adds support for the Texas Instruments ADS8344 ADC chip. This chip
has a 16-bit 8-Channel ADC and is access directly through SPI.
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
---
drivers/iio/adc/Kconfig | 10 ++
drivers/iio/adc/Makefile | 1 +
drivers/iio/adc/ti-ads8344.c | 200 +++++++++++++++++++++++++++++++++++
3 files changed, 211 insertions(+)
create mode 100644 drivers/iio/adc/ti-ads8344.c
diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 76db6e5cc296..447d3a871746 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -967,6 +967,16 @@ config TI_ADS7950
To compile this driver as a module, choose M here: the
module will be called ti-ads7950.
+config TI_ADS8344
+ tristate "Texas Instruments ADS8344"
+ depends on SPI && OF
+ help
+ If you say yes here you get support for Texas Instruments ADS8344
+ ADC chips
+
+ This driver can also be built as a module. If so, the module will be
+ called ti-ads8344.
+
config TI_ADS8688
tristate "Texas Instruments ADS8688"
depends on SPI && OF
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index 6fcebd167524..1f3ae934111d 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -87,6 +87,7 @@ obj-$(CONFIG_TI_ADC128S052) += ti-adc128s052.o
obj-$(CONFIG_TI_ADC161S626) += ti-adc161s626.o
obj-$(CONFIG_TI_ADS1015) += ti-ads1015.o
obj-$(CONFIG_TI_ADS7950) += ti-ads7950.o
+obj-$(CONFIG_TI_ADS8344) += ti-ads8344.o
obj-$(CONFIG_TI_ADS8688) += ti-ads8688.o
obj-$(CONFIG_TI_ADS124S08) += ti-ads124s08.o
obj-$(CONFIG_TI_AM335X_ADC) += ti_am335x_adc.o
diff --git a/drivers/iio/adc/ti-ads8344.c b/drivers/iio/adc/ti-ads8344.c
new file mode 100644
index 000000000000..649ed05bf1c9
--- /dev/null
+++ b/drivers/iio/adc/ti-ads8344.c
@@ -0,0 +1,200 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * ADS8344 16-bit 8-Channel ADC driver
+ *
+ * Author: Gregory CLEMENT <gregory.clement@bootlin.com>
+ *
+ * Datasheet: http://www.ti.com/lit/ds/symlink/ads8344.pdf
+ */
+
+#include <linux/delay.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/iio.h>
+#include <linux/module.h>
+#include <linux/regulator/consumer.h>
+#include <linux/spi/spi.h>
+
+#define ADS8344_START BIT(7)
+#define ADS8344_SINGLE_END BIT(2)
+#define ADS8344_CHANNEL(channel) ((channel) << 4)
+#define ADS8344_CLOCK_INTERNAL 0x2 /* PD1 = 1 and PD0 = 0 */
+
+struct ads8344 {
+ struct spi_device *spi;
+ struct regulator *reg;
+ struct mutex lock;
+
+ u8 tx_buf ____cacheline_aligned;
+ u16 rx_buf;
+};
+
+#define ADS8344_VOLTAGE_CHANNEL(chan, si) \
+ { \
+ .type = IIO_VOLTAGE, \
+ .indexed = 1, \
+ .channel = chan, \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
+ }
+
+#define ADS8344_VOLTAGE_CHANNEL_DIFF(chan1, chan2, si) \
+ { \
+ .type = IIO_VOLTAGE, \
+ .indexed = 1, \
+ .channel = (chan1), \
+ .channel2 = (chan2), \
+ .differential = 1, \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
+ }
+
+static const struct iio_chan_spec ads8344_channels[] = {
+ ADS8344_VOLTAGE_CHANNEL(0, 0),
+ ADS8344_VOLTAGE_CHANNEL(1, 4),
+ ADS8344_VOLTAGE_CHANNEL(2, 1),
+ ADS8344_VOLTAGE_CHANNEL(3, 5),
+ ADS8344_VOLTAGE_CHANNEL(4, 2),
+ ADS8344_VOLTAGE_CHANNEL(5, 6),
+ ADS8344_VOLTAGE_CHANNEL(6, 3),
+ ADS8344_VOLTAGE_CHANNEL(7, 7),
+ ADS8344_VOLTAGE_CHANNEL_DIFF(0, 1, 8),
+ ADS8344_VOLTAGE_CHANNEL_DIFF(2, 3, 9),
+ ADS8344_VOLTAGE_CHANNEL_DIFF(4, 5, 10),
+ ADS8344_VOLTAGE_CHANNEL_DIFF(6, 7, 11),
+ ADS8344_VOLTAGE_CHANNEL_DIFF(1, 0, 12),
+ ADS8344_VOLTAGE_CHANNEL_DIFF(3, 2, 13),
+ ADS8344_VOLTAGE_CHANNEL_DIFF(5, 4, 14),
+ ADS8344_VOLTAGE_CHANNEL_DIFF(7, 6, 15),
+};
+
+static int ads8344_adc_conversion(struct ads8344 *adc, int channel,
+ bool differential)
+{
+ struct spi_device *spi = adc->spi;
+ int ret;
+
+ adc->tx_buf = ADS8344_START;
+ if (!differential)
+ adc->tx_buf |= ADS8344_SINGLE_END;
+ adc->tx_buf |= ADS8344_CHANNEL(channel);
+ adc->tx_buf |= ADS8344_CLOCK_INTERNAL;
+
+ ret = spi_write(spi, &adc->tx_buf, 1);
+ if (ret)
+ return ret;
+
+ udelay(9);
+
+ ret = spi_read(spi, &adc->rx_buf, 2);
+ if (ret)
+ return ret;
+
+ return adc->rx_buf;
+}
+
+static int ads8344_read_raw(struct iio_dev *iio,
+ struct iio_chan_spec const *channel, int *value,
+ int *shift, long mask)
+{
+ struct ads8344 *adc = iio_priv(iio);
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ mutex_lock(&adc->lock);
+ *value = ads8344_adc_conversion(adc, channel->scan_index,
+ channel->differential);
+ mutex_unlock(&adc->lock);
+ if (*value < 0)
+ return *value;
+
+ return IIO_VAL_INT;
+ case IIO_CHAN_INFO_SCALE:
+ *value = regulator_get_voltage(adc->reg);
+ if (*value < 0)
+ return *value;
+
+ /* convert regulator output voltage to mV */
+ *value /= 1000;
+ *shift = 16;
+
+ return IIO_VAL_FRACTIONAL_LOG2;
+ default:
+ return -EINVAL;
+ }
+}
+
+static const struct iio_info ads8344_info = {
+ .read_raw = ads8344_read_raw,
+};
+
+static int ads8344_probe(struct spi_device *spi)
+{
+ struct iio_dev *indio_dev;
+ struct ads8344 *adc;
+ 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;
+ mutex_init(&adc->lock);
+
+ indio_dev->name = dev_name(&spi->dev);
+ indio_dev->dev.parent = &spi->dev;
+ indio_dev->dev.of_node = spi->dev.of_node;
+ indio_dev->info = &ads8344_info;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->channels = ads8344_channels;
+ indio_dev->num_channels = ARRAY_SIZE(ads8344_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)
+ return ret;
+
+ spi_set_drvdata(spi, indio_dev);
+
+ ret = iio_device_register(indio_dev);
+ if (ret) {
+ regulator_disable(adc->reg);
+ return ret;
+ }
+
+ return 0;
+}
+
+static int ads8344_remove(struct spi_device *spi)
+{
+ struct iio_dev *indio_dev = spi_get_drvdata(spi);
+ struct ads8344 *adc = iio_priv(indio_dev);
+
+ iio_device_unregister(indio_dev);
+ regulator_disable(adc->reg);
+
+ return 0;
+}
+
+static const struct of_device_id ads8344_of_match[] = {
+ { .compatible = "ti,ads8344", },
+ {}
+};
+MODULE_DEVICE_TABLE(of, ads8344_dt_ids);
+
+static struct spi_driver ads8344_driver = {
+ .driver = {
+ .name = "ads8344",
+ .of_match_table = ads8344_of_match,
+ },
+ .probe = ads8344_probe,
+ .remove = ads8344_remove,
+};
+module_spi_driver(ads8344_driver);
+
+MODULE_AUTHOR("Gregory CLEMENT <gregory.clement@bootlin.com>");
+MODULE_DESCRIPTION("ADS8344 driver");
+MODULE_LICENSE("GPL v2");
--
2.20.1
next prev parent reply other threads:[~2019-03-22 11:11 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-22 11:11 [PATCH v2 0/2] Add support for the TI ADS8344 A/DC chips Gregory CLEMENT
2019-03-22 11:11 ` [PATCH v2 1/2] dt-bindings: iio: adc: Add bindings for " Gregory CLEMENT
2019-03-31 6:41 ` Rob Herring
2019-03-22 11:11 ` Gregory CLEMENT [this message]
2019-03-24 15:16 ` [PATCH v2 2/2] iio: adc: Add driver for the " Himanshu Jha
2019-03-24 16:01 ` Jonathan Cameron
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