summaryrefslogtreecommitdiffstats
path: root/drivers/iio/dac
diff options
context:
space:
mode:
authorRicardo Ribalda Delgado <ricardo@ribalda.com>2019-02-04 13:48:32 +0100
committerJonathan Cameron <Jonathan.Cameron@huawei.com>2019-02-09 19:46:02 +0100
commit977724d20584bd268b0a84bc2fbfffbc8681b595 (patch)
treecd56912b8f8790363a9d227faa4ee6aae6222d9a /drivers/iio/dac
parentiio: adc: ad7476: Add support for TI ADS786X ADCs (diff)
downloadlinux-977724d20584bd268b0a84bc2fbfffbc8681b595.tar.xz
linux-977724d20584bd268b0a84bc2fbfffbc8681b595.zip
iio:dac:ti-dac7612: Add driver for Texas Instruments DAC7612
It is a driver for Texas Instruments Dual, 12-Bit Serial Input Digital-to-Analog Converter. Datasheet of this chip: http://www.ti.com/lit/ds/sbas106/sbas106.pdf Signed-off-by: Ricardo Ribalda Delgado <ricardo@ribalda.com> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Diffstat (limited to 'drivers/iio/dac')
-rw-r--r--drivers/iio/dac/Kconfig10
-rw-r--r--drivers/iio/dac/Makefile1
-rw-r--r--drivers/iio/dac/ti-dac7612.c184
3 files changed, 195 insertions, 0 deletions
diff --git a/drivers/iio/dac/Kconfig b/drivers/iio/dac/Kconfig
index f28daf67db6a..fbef9107acad 100644
--- a/drivers/iio/dac/Kconfig
+++ b/drivers/iio/dac/Kconfig
@@ -375,6 +375,16 @@ config TI_DAC7311
If compiled as a module, it will be called ti-dac7311.
+config TI_DAC7612
+ tristate "Texas Instruments 12-bit 2-channel DAC driver"
+ depends on SPI_MASTER && GPIOLIB
+ help
+ Driver for the Texas Instruments DAC7612, DAC7612U, DAC7612UB
+ The driver hand drive the load pin automatically, otherwise
+ it needs to be toggled manually.
+
+ If compiled as a module, it will be called ti-dac7612.
+
config VF610_DAC
tristate "Vybrid vf610 DAC driver"
depends on OF
diff --git a/drivers/iio/dac/Makefile b/drivers/iio/dac/Makefile
index f0a37c93de8e..1369fa1d2f0e 100644
--- a/drivers/iio/dac/Makefile
+++ b/drivers/iio/dac/Makefile
@@ -41,4 +41,5 @@ obj-$(CONFIG_STM32_DAC) += stm32-dac.o
obj-$(CONFIG_TI_DAC082S085) += ti-dac082s085.o
obj-$(CONFIG_TI_DAC5571) += ti-dac5571.o
obj-$(CONFIG_TI_DAC7311) += ti-dac7311.o
+obj-$(CONFIG_TI_DAC7612) += ti-dac7612.o
obj-$(CONFIG_VF610_DAC) += vf610_dac.o
diff --git a/drivers/iio/dac/ti-dac7612.c b/drivers/iio/dac/ti-dac7612.c
new file mode 100644
index 000000000000..c46805144dd4
--- /dev/null
+++ b/drivers/iio/dac/ti-dac7612.c
@@ -0,0 +1,184 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * DAC7612 Dual, 12-Bit Serial input Digital-to-Analog Converter
+ *
+ * Copyright 2019 Qtechnology A/S
+ * 2019 Ricardo Ribalda <ricardo@ribalda.com>
+ *
+ * Licensed under the GPL-2.
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/spi/spi.h>
+#include <linux/gpio/consumer.h>
+#include <linux/iio/iio.h>
+
+#define DAC7612_RESOLUTION 12
+#define DAC7612_ADDRESS 4
+#define DAC7612_START 5
+
+struct dac7612 {
+ struct spi_device *spi;
+ struct gpio_desc *loaddacs;
+ uint16_t cache[2];
+
+ /*
+ * DMA (thus cache coherency maintenance) requires the
+ * transfer buffers to live in their own cache lines.
+ */
+ uint8_t data[2] ____cacheline_aligned;
+};
+
+static int dac7612_cmd_single(struct dac7612 *priv, int channel, u16 val)
+{
+ int ret;
+
+ priv->data[0] = BIT(DAC7612_START) | (channel << DAC7612_ADDRESS);
+ priv->data[0] |= val >> 8;
+ priv->data[1] = val & 0xff;
+
+ priv->cache[channel] = val;
+
+ ret = spi_write(priv->spi, priv->data, sizeof(priv->data));
+ if (ret)
+ return ret;
+
+ gpiod_set_value(priv->loaddacs, 1);
+ gpiod_set_value(priv->loaddacs, 0);
+
+ return 0;
+}
+
+#define dac7612_CHANNEL(chan, name) { \
+ .type = IIO_VOLTAGE, \
+ .channel = (chan), \
+ .indexed = 1, \
+ .output = 1, \
+ .datasheet_name = name, \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
+}
+
+static const struct iio_chan_spec dac7612_channels[] = {
+ dac7612_CHANNEL(0, "OUTA"),
+ dac7612_CHANNEL(1, "OUTB"),
+};
+
+static int dac7612_read_raw(struct iio_dev *iio_dev,
+ const struct iio_chan_spec *chan,
+ int *val, int *val2, long mask)
+{
+ struct dac7612 *priv;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ priv = iio_priv(iio_dev);
+ *val = priv->cache[chan->channel];
+ return IIO_VAL_INT;
+
+ case IIO_CHAN_INFO_SCALE:
+ *val = 1;
+ return IIO_VAL_INT;
+
+ default:
+ return -EINVAL;
+ }
+}
+
+static int dac7612_write_raw(struct iio_dev *iio_dev,
+ const struct iio_chan_spec *chan,
+ int val, int val2, long mask)
+{
+ struct dac7612 *priv = iio_priv(iio_dev);
+ int ret;
+
+ if (mask != IIO_CHAN_INFO_RAW)
+ return -EINVAL;
+
+ if ((val >= BIT(DAC7612_RESOLUTION)) || val < 0 || val2)
+ return -EINVAL;
+
+ if (val == priv->cache[chan->channel])
+ return 0;
+
+ mutex_lock(&iio_dev->mlock);
+ ret = dac7612_cmd_single(priv, chan->channel, val);
+ mutex_unlock(&iio_dev->mlock);
+
+ return ret;
+}
+
+static const struct iio_info dac7612_info = {
+ .read_raw = dac7612_read_raw,
+ .write_raw = dac7612_write_raw,
+};
+
+static int dac7612_probe(struct spi_device *spi)
+{
+ struct iio_dev *iio_dev;
+ struct dac7612 *priv;
+ int i;
+ int ret;
+
+ iio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*priv));
+ if (!iio_dev)
+ return -ENOMEM;
+
+ priv = iio_priv(iio_dev);
+ /*
+ * LOADDACS pin can be controlled by the driver or externally.
+ * When controlled by the driver, the DAC value is updated after
+ * every write.
+ * When the driver does not control the PIN, the user or an external
+ * event can change the value of all DACs by pulsing down the LOADDACs
+ * pin.
+ */
+ priv->loaddacs = devm_gpiod_get_optional(&spi->dev, "ti,loaddacs",
+ GPIOD_OUT_LOW);
+ if (IS_ERR(priv->loaddacs))
+ return PTR_ERR(priv->loaddacs);
+ priv->spi = spi;
+ spi_set_drvdata(spi, iio_dev);
+ iio_dev->dev.parent = &spi->dev;
+ iio_dev->info = &dac7612_info;
+ iio_dev->modes = INDIO_DIRECT_MODE;
+ iio_dev->channels = dac7612_channels;
+ iio_dev->num_channels = ARRAY_SIZE(priv->cache);
+ iio_dev->name = spi_get_device_id(spi)->name;
+
+ for (i = 0; i < ARRAY_SIZE(priv->cache); i++) {
+ ret = dac7612_cmd_single(priv, i, 0);
+ if (ret)
+ return ret;
+ }
+
+ return devm_iio_device_register(&spi->dev, iio_dev);
+}
+
+static const struct spi_device_id dac7612_id[] = {
+ {"ti-dac7612"},
+ {}
+};
+MODULE_DEVICE_TABLE(spi, dac7612_id);
+
+static const struct of_device_id dac7612_of_match[] = {
+ { .compatible = "ti,dac7612" },
+ { .compatible = "ti,dac7612u" },
+ { .compatible = "ti,dac7612ub" },
+ { },
+};
+MODULE_DEVICE_TABLE(of, dac7612_of_match);
+
+static struct spi_driver dac7612_driver = {
+ .driver = {
+ .name = "ti-dac7612",
+ .of_match_table = dac7612_of_match,
+ },
+ .probe = dac7612_probe,
+ .id_table = dac7612_id,
+};
+module_spi_driver(dac7612_driver);
+
+MODULE_AUTHOR("Ricardo Ribalda <ricardo@ribalda.com>");
+MODULE_DESCRIPTION("Texas Instruments DAC7612 DAC driver");
+MODULE_LICENSE("GPL v2");