--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+/* ti-dac7311.c - Texas Instruments 8/10/12-bit 1-channel DAC driver
+ *
+ * Copyright (C) 2018 CMC NV
+ *
+ * http://www.ti.com/lit/ds/symlink/dac7311.pdf
+ */
+
+#include <linux/iio/iio.h>
+#include <linux/module.h>
+#include <linux/regulator/consumer.h>
+#include <linux/spi/spi.h>
+
+enum {
+ ID_DAC5311 = 0,
+ ID_DAC6311,
+ ID_DAC7311,
+};
+
+enum {
+ POWER_1KOHM_TO_GND = 0,
+ POWER_100KOHM_TO_GND,
+ POWER_TRI_STATE,
+};
+
+struct ti_dac_spec {
+ u8 resolution;
+};
+
+static const struct ti_dac_spec ti_dac_spec[] = {
+ [ID_DAC5311] = { .resolution = 8 },
+ [ID_DAC6311] = { .resolution = 10 },
+ [ID_DAC7311] = { .resolution = 12 },
+};
+
+/**
+ * struct ti_dac_chip - TI DAC chip
+ * @lock: protects write sequences
+ * @vref: regulator generating Vref
+ * @spi: SPI device to send data to the device
+ * @val: cached value
+ * @powerdown: whether the chip is powered down
+ * @powerdown_mode: selected by the user
+ * @resolution: resolution of the chip
+ * @buf: buffer for transfer data
+ */
+struct ti_dac_chip {
+ struct mutex lock;
+ struct regulator *vref;
+ struct spi_device *spi;
+ u16 val;
+ bool powerdown;
+ u8 powerdown_mode;
+ u8 resolution;
+ u8 buf[2] ____cacheline_aligned;
+};
+
+static u8 ti_dac_get_power(struct ti_dac_chip *ti_dac, bool powerdown)
+{
+ if (powerdown)
+ return ti_dac->powerdown_mode + 1;
+
+ return 0;
+}
+
+static int ti_dac_cmd(struct ti_dac_chip *ti_dac, u8 power, u16 val)
+{
+ u8 shift = 14 - ti_dac->resolution;
+
+ ti_dac->buf[0] = (val << shift) & 0xFF;
+ ti_dac->buf[1] = (power << 6) | (val >> (8 - shift));
+ return spi_write(ti_dac->spi, ti_dac->buf, 2);
+}
+
+static const char * const ti_dac_powerdown_modes[] = {
+ "1kohm_to_gnd",
+ "100kohm_to_gnd",
+ "three_state",
+};
+
+static int ti_dac_get_powerdown_mode(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan)
+{
+ struct ti_dac_chip *ti_dac = iio_priv(indio_dev);
+
+ return ti_dac->powerdown_mode;
+}
+
+static int ti_dac_set_powerdown_mode(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan,
+ unsigned int mode)
+{
+ struct ti_dac_chip *ti_dac = iio_priv(indio_dev);
+
+ ti_dac->powerdown_mode = mode;
+ return 0;
+}
+
+static const struct iio_enum ti_dac_powerdown_mode = {
+ .items = ti_dac_powerdown_modes,
+ .num_items = ARRAY_SIZE(ti_dac_powerdown_modes),
+ .get = ti_dac_get_powerdown_mode,
+ .set = ti_dac_set_powerdown_mode,
+};
+
+static ssize_t ti_dac_read_powerdown(struct iio_dev *indio_dev,
+ uintptr_t private,
+ const struct iio_chan_spec *chan,
+ char *buf)
+{
+ struct ti_dac_chip *ti_dac = iio_priv(indio_dev);
+
+ return sprintf(buf, "%d\n", ti_dac->powerdown);
+}
+
+static ssize_t ti_dac_write_powerdown(struct iio_dev *indio_dev,
+ uintptr_t private,
+ const struct iio_chan_spec *chan,
+ const char *buf, size_t len)
+{
+ struct ti_dac_chip *ti_dac = iio_priv(indio_dev);
+ bool powerdown;
+ u8 power;
+ int ret;
+
+ ret = strtobool(buf, &powerdown);
+ if (ret)
+ return ret;
+
+ power = ti_dac_get_power(ti_dac, powerdown);
+
+ mutex_lock(&ti_dac->lock);
+ ret = ti_dac_cmd(ti_dac, power, 0);
+ if (!ret)
+ ti_dac->powerdown = powerdown;
+ mutex_unlock(&ti_dac->lock);
+
+ return ret ? ret : len;
+}
+
+static const struct iio_chan_spec_ext_info ti_dac_ext_info[] = {
+ {
+ .name = "powerdown",
+ .read = ti_dac_read_powerdown,
+ .write = ti_dac_write_powerdown,
+ .shared = IIO_SHARED_BY_TYPE,
+ },
+ IIO_ENUM("powerdown_mode", IIO_SHARED_BY_TYPE, &ti_dac_powerdown_mode),
+ IIO_ENUM_AVAILABLE("powerdown_mode", &ti_dac_powerdown_mode),
+ { },
+};
+
+#define TI_DAC_CHANNEL(chan) { \
+ .type = IIO_VOLTAGE, \
+ .channel = (chan), \
+ .output = true, \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
+ .ext_info = ti_dac_ext_info, \
+}
+
+static const struct iio_chan_spec ti_dac_channels[] = {
+ TI_DAC_CHANNEL(0),
+};
+
+static int ti_dac_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val, int *val2, long mask)
+{
+ struct ti_dac_chip *ti_dac = iio_priv(indio_dev);
+ int ret;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ *val = ti_dac->val;
+ return IIO_VAL_INT;
+
+ case IIO_CHAN_INFO_SCALE:
+ ret = regulator_get_voltage(ti_dac->vref);
+ if (ret < 0)
+ return ret;
+
+ *val = ret / 1000;
+ *val2 = ti_dac->resolution;
+ return IIO_VAL_FRACTIONAL_LOG2;
+ }
+
+ return -EINVAL;
+}
+
+static int ti_dac_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int val, int val2, long mask)
+{
+ struct ti_dac_chip *ti_dac = iio_priv(indio_dev);
+ u8 power = ti_dac_get_power(ti_dac, ti_dac->powerdown);
+ int ret;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ if (ti_dac->val == val)
+ return 0;
+
+ if (val >= (1 << ti_dac->resolution) || val < 0)
+ return -EINVAL;
+
+ if (ti_dac->powerdown)
+ return -EBUSY;
+
+ mutex_lock(&ti_dac->lock);
+ ret = ti_dac_cmd(ti_dac, power, val);
+ if (!ret)
+ ti_dac->val = val;
+ mutex_unlock(&ti_dac->lock);
+ break;
+
+ default:
+ ret = -EINVAL;
+ }
+
+ return ret;
+}
+
+static int ti_dac_write_raw_get_fmt(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, long mask)
+{
+ return IIO_VAL_INT;
+}
+
+static const struct iio_info ti_dac_info = {
+ .read_raw = ti_dac_read_raw,
+ .write_raw = ti_dac_write_raw,
+ .write_raw_get_fmt = ti_dac_write_raw_get_fmt,
+};
+
+static int ti_dac_probe(struct spi_device *spi)
+{
+ struct device *dev = &spi->dev;
+ const struct ti_dac_spec *spec;
+ struct ti_dac_chip *ti_dac;
+ struct iio_dev *indio_dev;
+ int ret;
+
+ indio_dev = devm_iio_device_alloc(dev, sizeof(*ti_dac));
+ if (!indio_dev) {
+ dev_err(dev, "can not allocate iio device\n");
+ return -ENOMEM;
+ }
+
+ spi->mode = SPI_MODE_1;
+ spi->bits_per_word = 16;
+ spi_setup(spi);
+
+ indio_dev->dev.parent = dev;
+ indio_dev->dev.of_node = spi->dev.of_node;
+ indio_dev->info = &ti_dac_info;
+ indio_dev->name = spi_get_device_id(spi)->name;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->channels = ti_dac_channels;
+ spi_set_drvdata(spi, indio_dev);
+
+ ti_dac = iio_priv(indio_dev);
+ ti_dac->powerdown = false;
+ ti_dac->spi = spi;
+
+ spec = &ti_dac_spec[spi_get_device_id(spi)->driver_data];
+ indio_dev->num_channels = 1;
+ ti_dac->resolution = spec->resolution;
+
+ ti_dac->vref = devm_regulator_get(dev, "vref");
+ if (IS_ERR(ti_dac->vref)) {
+ dev_err(dev, "error to get regulator\n");
+ return PTR_ERR(ti_dac->vref);
+ }
+
+ ret = regulator_enable(ti_dac->vref);
+ if (ret < 0) {
+ dev_err(dev, "can not enable regulator\n");
+ return ret;
+ }
+
+ mutex_init(&ti_dac->lock);
+
+ ret = iio_device_register(indio_dev);
+ if (ret) {
+ dev_err(dev, "fail to register iio device: %d\n", ret);
+ goto err;
+ }
+
+ return 0;
+
+err:
+ mutex_destroy(&ti_dac->lock);
+ regulator_disable(ti_dac->vref);
+ return ret;
+}
+
+static int ti_dac_remove(struct spi_device *spi)
+{
+ struct iio_dev *indio_dev = spi_get_drvdata(spi);
+ struct ti_dac_chip *ti_dac = iio_priv(indio_dev);
+
+ iio_device_unregister(indio_dev);
+ mutex_destroy(&ti_dac->lock);
+ regulator_disable(ti_dac->vref);
+ return 0;
+}
+
+static const struct of_device_id ti_dac_of_id[] = {
+ { .compatible = "ti,dac5311" },
+ { .compatible = "ti,dac6311" },
+ { .compatible = "ti,dac7311" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, ti_dac_of_id);
+
+static const struct spi_device_id ti_dac_spi_id[] = {
+ { "dac5311", ID_DAC5311 },
+ { "dac6311", ID_DAC6311 },
+ { "dac7311", ID_DAC7311 },
+ { }
+};
+MODULE_DEVICE_TABLE(spi, ti_dac_spi_id);
+
+static struct spi_driver ti_dac_driver = {
+ .driver = {
+ .name = "ti-dac7311",
+ .of_match_table = ti_dac_of_id,
+ },
+ .probe = ti_dac_probe,
+ .remove = ti_dac_remove,
+ .id_table = ti_dac_spi_id,
+};
+module_spi_driver(ti_dac_driver);
+
+MODULE_AUTHOR("Charles-Antoine Couret <charles-antoine.couret@essensium.com>");
+MODULE_DESCRIPTION("Texas Instruments 8/10/12-bit 1-channel DAC driver");
+MODULE_LICENSE("GPL v2");
projects / linux-2.6-microblaze.git / blobdiff