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path: root/drivers/iio/adc/ad7091r-base.c
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Diffstat (limited to 'drivers/iio/adc/ad7091r-base.c')
-rw-r--r--drivers/iio/adc/ad7091r-base.c298
1 files changed, 298 insertions, 0 deletions
diff --git a/drivers/iio/adc/ad7091r-base.c b/drivers/iio/adc/ad7091r-base.c
new file mode 100644
index 000000000000..33c40357bd5e
--- /dev/null
+++ b/drivers/iio/adc/ad7091r-base.c
@@ -0,0 +1,298 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * AD7091RX Analog to Digital converter driver
+ *
+ * Copyright 2014-2019 Analog Devices Inc.
+ */
+
+#include <linux/bitops.h>
+#include <linux/iio/events.h>
+#include <linux/iio/iio.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+
+#include "ad7091r-base.h"
+
+#define AD7091R_REG_RESULT 0
+#define AD7091R_REG_CHANNEL 1
+#define AD7091R_REG_CONF 2
+#define AD7091R_REG_ALERT 3
+#define AD7091R_REG_CH_LOW_LIMIT(ch) ((ch) * 3 + 4)
+#define AD7091R_REG_CH_HIGH_LIMIT(ch) ((ch) * 3 + 5)
+#define AD7091R_REG_CH_HYSTERESIS(ch) ((ch) * 3 + 6)
+
+/* AD7091R_REG_RESULT */
+#define AD7091R_REG_RESULT_CH_ID(x) (((x) >> 13) & 0x3)
+#define AD7091R_REG_RESULT_CONV_RESULT(x) ((x) & 0xfff)
+
+/* AD7091R_REG_CONF */
+#define AD7091R_REG_CONF_AUTO BIT(8)
+#define AD7091R_REG_CONF_CMD BIT(10)
+
+#define AD7091R_REG_CONF_MODE_MASK \
+ (AD7091R_REG_CONF_AUTO | AD7091R_REG_CONF_CMD)
+
+enum ad7091r_mode {
+ AD7091R_MODE_SAMPLE,
+ AD7091R_MODE_COMMAND,
+ AD7091R_MODE_AUTOCYCLE,
+};
+
+struct ad7091r_state {
+ struct device *dev;
+ struct regmap *map;
+ struct regulator *vref;
+ const struct ad7091r_chip_info *chip_info;
+ enum ad7091r_mode mode;
+ struct mutex lock; /*lock to prevent concurent reads */
+};
+
+static int ad7091r_set_mode(struct ad7091r_state *st, enum ad7091r_mode mode)
+{
+ int ret, conf;
+
+ switch (mode) {
+ case AD7091R_MODE_SAMPLE:
+ conf = 0;
+ break;
+ case AD7091R_MODE_COMMAND:
+ conf = AD7091R_REG_CONF_CMD;
+ break;
+ case AD7091R_MODE_AUTOCYCLE:
+ conf = AD7091R_REG_CONF_AUTO;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ ret = regmap_update_bits(st->map, AD7091R_REG_CONF,
+ AD7091R_REG_CONF_MODE_MASK, conf);
+ if (ret)
+ return ret;
+
+ st->mode = mode;
+
+ return 0;
+}
+
+static int ad7091r_set_channel(struct ad7091r_state *st, unsigned int channel)
+{
+ unsigned int dummy;
+ int ret;
+
+ /* AD7091R_REG_CHANNEL specified which channels to be converted */
+ ret = regmap_write(st->map, AD7091R_REG_CHANNEL,
+ BIT(channel) | (BIT(channel) << 8));
+ if (ret)
+ return ret;
+
+ /*
+ * There is a latency of one conversion before the channel conversion
+ * sequence is updated
+ */
+ return regmap_read(st->map, AD7091R_REG_RESULT, &dummy);
+}
+
+static int ad7091r_read_one(struct iio_dev *iio_dev,
+ unsigned int channel, unsigned int *read_val)
+{
+ struct ad7091r_state *st = iio_priv(iio_dev);
+ unsigned int val;
+ int ret;
+
+ ret = ad7091r_set_channel(st, channel);
+ if (ret)
+ return ret;
+
+ ret = regmap_read(st->map, AD7091R_REG_RESULT, &val);
+ if (ret)
+ return ret;
+
+ if (AD7091R_REG_RESULT_CH_ID(val) != channel)
+ return -EIO;
+
+ *read_val = AD7091R_REG_RESULT_CONV_RESULT(val);
+
+ return 0;
+}
+
+static int ad7091r_read_raw(struct iio_dev *iio_dev,
+ struct iio_chan_spec const *chan,
+ int *val, int *val2, long m)
+{
+ struct ad7091r_state *st = iio_priv(iio_dev);
+ unsigned int read_val;
+ int ret;
+
+ mutex_lock(&st->lock);
+
+ switch (m) {
+ case IIO_CHAN_INFO_RAW:
+ if (st->mode != AD7091R_MODE_COMMAND) {
+ ret = -EBUSY;
+ goto unlock;
+ }
+
+ ret = ad7091r_read_one(iio_dev, chan->channel, &read_val);
+ if (ret)
+ goto unlock;
+
+ *val = read_val;
+ ret = IIO_VAL_INT;
+ break;
+
+ case IIO_CHAN_INFO_SCALE:
+ if (st->vref) {
+ ret = regulator_get_voltage(st->vref);
+ if (ret < 0)
+ goto unlock;
+
+ *val = ret / 1000;
+ } else {
+ *val = st->chip_info->vref_mV;
+ }
+
+ *val2 = chan->scan_type.realbits;
+ ret = IIO_VAL_FRACTIONAL_LOG2;
+ break;
+
+ default:
+ ret = -EINVAL;
+ break;
+ }
+
+unlock:
+ mutex_unlock(&st->lock);
+ return ret;
+}
+
+static const struct iio_info ad7091r_info = {
+ .read_raw = ad7091r_read_raw,
+};
+
+static irqreturn_t ad7091r_event_handler(int irq, void *private)
+{
+ struct ad7091r_state *st = (struct ad7091r_state *) private;
+ struct iio_dev *iio_dev = dev_get_drvdata(st->dev);
+ unsigned int i, read_val;
+ int ret;
+ s64 timestamp = iio_get_time_ns(iio_dev);
+
+ ret = regmap_read(st->map, AD7091R_REG_ALERT, &read_val);
+ if (ret)
+ return IRQ_HANDLED;
+
+ for (i = 0; i < st->chip_info->num_channels; i++) {
+ if (read_val & BIT(i * 2))
+ iio_push_event(iio_dev,
+ IIO_UNMOD_EVENT_CODE(IIO_VOLTAGE, i,
+ IIO_EV_TYPE_THRESH,
+ IIO_EV_DIR_RISING), timestamp);
+ if (read_val & BIT(i * 2 + 1))
+ iio_push_event(iio_dev,
+ IIO_UNMOD_EVENT_CODE(IIO_VOLTAGE, i,
+ IIO_EV_TYPE_THRESH,
+ IIO_EV_DIR_FALLING), timestamp);
+ }
+
+ return IRQ_HANDLED;
+}
+
+static void ad7091r_remove(void *data)
+{
+ struct ad7091r_state *st = data;
+
+ regulator_disable(st->vref);
+}
+
+int ad7091r_probe(struct device *dev, const char *name,
+ const struct ad7091r_chip_info *chip_info,
+ struct regmap *map, int irq)
+{
+ struct iio_dev *iio_dev;
+ struct ad7091r_state *st;
+ int ret;
+
+ iio_dev = devm_iio_device_alloc(dev, sizeof(*st));
+ if (!iio_dev)
+ return -ENOMEM;
+
+ st = iio_priv(iio_dev);
+ st->dev = dev;
+ st->chip_info = chip_info;
+ st->map = map;
+
+ iio_dev->dev.parent = dev;
+ iio_dev->name = name;
+ iio_dev->info = &ad7091r_info;
+ iio_dev->modes = INDIO_DIRECT_MODE;
+
+ iio_dev->num_channels = chip_info->num_channels;
+ iio_dev->channels = chip_info->channels;
+
+ if (irq) {
+ ret = devm_request_threaded_irq(dev, irq, NULL,
+ ad7091r_event_handler,
+ IRQF_TRIGGER_FALLING | IRQF_ONESHOT, name, st);
+ if (ret)
+ return ret;
+ }
+
+ st->vref = devm_regulator_get_optional(dev, "vref");
+ if (IS_ERR(st->vref)) {
+ if (PTR_ERR(st->vref) == -EPROBE_DEFER)
+ return -EPROBE_DEFER;
+ st->vref = NULL;
+ } else {
+ ret = regulator_enable(st->vref);
+ if (ret)
+ return ret;
+ ret = devm_add_action_or_reset(dev, ad7091r_remove, st);
+ if (ret)
+ return ret;
+ }
+
+ /* Use command mode by default to convert only desired channels*/
+ ret = ad7091r_set_mode(st, AD7091R_MODE_COMMAND);
+ if (ret)
+ return ret;
+
+ return devm_iio_device_register(dev, iio_dev);
+}
+EXPORT_SYMBOL_GPL(ad7091r_probe);
+
+static bool ad7091r_writeable_reg(struct device *dev, unsigned int reg)
+{
+ switch (reg) {
+ case AD7091R_REG_RESULT:
+ case AD7091R_REG_ALERT:
+ return false;
+ default:
+ return true;
+ }
+}
+
+static bool ad7091r_volatile_reg(struct device *dev, unsigned int reg)
+{
+ switch (reg) {
+ case AD7091R_REG_RESULT:
+ case AD7091R_REG_ALERT:
+ return true;
+ default:
+ return false;
+ }
+}
+
+const struct regmap_config ad7091r_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 16,
+ .writeable_reg = ad7091r_writeable_reg,
+ .volatile_reg = ad7091r_volatile_reg,
+};
+EXPORT_SYMBOL_GPL(ad7091r_regmap_config);
+
+MODULE_AUTHOR("Beniamin Bia <beniamin.bia@analog.com>");
+MODULE_DESCRIPTION("Analog Devices AD7091Rx multi-channel converters");
+MODULE_LICENSE("GPL v2");