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-rw-r--r--drivers/staging/iio/adc/Kconfig18
-rw-r--r--drivers/staging/iio/adc/Makefile6
-rw-r--r--drivers/staging/iio/adc/ad7816.c451
3 files changed, 475 insertions, 0 deletions
diff --git a/drivers/staging/iio/adc/Kconfig b/drivers/staging/iio/adc/Kconfig
new file mode 100644
index 000000000..2f0d6cf04
--- /dev/null
+++ b/drivers/staging/iio/adc/Kconfig
@@ -0,0 +1,18 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# ADC drivers
+#
+menu "Analog to digital converters"
+
+config AD7816
+ tristate "Analog Devices AD7816/7/8 temperature sensor and ADC driver"
+ depends on SPI
+ depends on GPIOLIB || COMPILE_TEST
+ help
+ Say yes here to build support for Analog Devices AD7816/7/8
+ temperature sensors and ADC.
+
+ To compile this driver as a module, choose M here: the
+ module will be called ad7816.
+
+endmenu
diff --git a/drivers/staging/iio/adc/Makefile b/drivers/staging/iio/adc/Makefile
new file mode 100644
index 000000000..1e2a94c4d
--- /dev/null
+++ b/drivers/staging/iio/adc/Makefile
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for industrial I/O ADC drivers
+#
+
+obj-$(CONFIG_AD7816) += ad7816.o
diff --git a/drivers/staging/iio/adc/ad7816.c b/drivers/staging/iio/adc/ad7816.c
new file mode 100644
index 000000000..6c14d7bcd
--- /dev/null
+++ b/drivers/staging/iio/adc/ad7816.c
@@ -0,0 +1,451 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * AD7816 digital temperature sensor driver supporting AD7816/7/8
+ *
+ * Copyright 2010 Analog Devices Inc.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/gpio/consumer.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/sysfs.h>
+#include <linux/list.h>
+#include <linux/spi/spi.h>
+#include <linux/module.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/events.h>
+
+/*
+ * AD7816 config masks
+ */
+#define AD7816_FULL 0x1
+#define AD7816_PD 0x2
+#define AD7816_CS_MASK 0x7
+#define AD7816_CS_MAX 0x4
+
+/*
+ * AD7816 temperature masks
+ */
+#define AD7816_VALUE_OFFSET 6
+#define AD7816_BOUND_VALUE_BASE 0x8
+#define AD7816_BOUND_VALUE_MIN -95
+#define AD7816_BOUND_VALUE_MAX 152
+#define AD7816_TEMP_FLOAT_OFFSET 2
+#define AD7816_TEMP_FLOAT_MASK 0x3
+
+/*
+ * struct ad7816_chip_info - chip specific information
+ */
+
+struct ad7816_chip_info {
+ kernel_ulong_t id;
+ struct spi_device *spi_dev;
+ struct gpio_desc *rdwr_pin;
+ struct gpio_desc *convert_pin;
+ struct gpio_desc *busy_pin;
+ u8 oti_data[AD7816_CS_MAX + 1];
+ u8 channel_id; /* 0 always be temperature */
+ u8 mode;
+};
+
+enum ad7816_type {
+ ID_AD7816,
+ ID_AD7817,
+ ID_AD7818,
+};
+
+/*
+ * ad7816 data access by SPI
+ */
+static int ad7816_spi_read(struct ad7816_chip_info *chip, u16 *data)
+{
+ struct spi_device *spi_dev = chip->spi_dev;
+ int ret;
+ __be16 buf;
+
+ gpiod_set_value(chip->rdwr_pin, 1);
+ gpiod_set_value(chip->rdwr_pin, 0);
+ ret = spi_write(spi_dev, &chip->channel_id, sizeof(chip->channel_id));
+ if (ret < 0) {
+ dev_err(&spi_dev->dev, "SPI channel setting error\n");
+ return ret;
+ }
+ gpiod_set_value(chip->rdwr_pin, 1);
+
+ if (chip->mode == AD7816_PD) { /* operating mode 2 */
+ gpiod_set_value(chip->convert_pin, 1);
+ gpiod_set_value(chip->convert_pin, 0);
+ } else { /* operating mode 1 */
+ gpiod_set_value(chip->convert_pin, 0);
+ gpiod_set_value(chip->convert_pin, 1);
+ }
+
+ if (chip->id == ID_AD7816 || chip->id == ID_AD7817) {
+ while (gpiod_get_value(chip->busy_pin))
+ cpu_relax();
+ }
+
+ gpiod_set_value(chip->rdwr_pin, 0);
+ gpiod_set_value(chip->rdwr_pin, 1);
+ ret = spi_read(spi_dev, &buf, sizeof(*data));
+ if (ret < 0) {
+ dev_err(&spi_dev->dev, "SPI data read error\n");
+ return ret;
+ }
+
+ *data = be16_to_cpu(buf);
+
+ return ret;
+}
+
+static int ad7816_spi_write(struct ad7816_chip_info *chip, u8 data)
+{
+ struct spi_device *spi_dev = chip->spi_dev;
+ int ret;
+
+ gpiod_set_value(chip->rdwr_pin, 1);
+ gpiod_set_value(chip->rdwr_pin, 0);
+ ret = spi_write(spi_dev, &data, sizeof(data));
+ if (ret < 0)
+ dev_err(&spi_dev->dev, "SPI oti data write error\n");
+
+ return ret;
+}
+
+static ssize_t ad7816_show_mode(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+ struct ad7816_chip_info *chip = iio_priv(indio_dev);
+
+ if (chip->mode)
+ return sprintf(buf, "power-save\n");
+ return sprintf(buf, "full\n");
+}
+
+static ssize_t ad7816_store_mode(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf,
+ size_t len)
+{
+ struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+ struct ad7816_chip_info *chip = iio_priv(indio_dev);
+
+ if (strcmp(buf, "full")) {
+ gpiod_set_value(chip->rdwr_pin, 1);
+ chip->mode = AD7816_FULL;
+ } else {
+ gpiod_set_value(chip->rdwr_pin, 0);
+ chip->mode = AD7816_PD;
+ }
+
+ return len;
+}
+
+static IIO_DEVICE_ATTR(mode, 0644,
+ ad7816_show_mode,
+ ad7816_store_mode,
+ 0);
+
+static ssize_t ad7816_show_available_modes(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ return sprintf(buf, "full\npower-save\n");
+}
+
+static IIO_DEVICE_ATTR(available_modes, 0444, ad7816_show_available_modes,
+ NULL, 0);
+
+static ssize_t ad7816_show_channel(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+ struct ad7816_chip_info *chip = iio_priv(indio_dev);
+
+ return sprintf(buf, "%d\n", chip->channel_id);
+}
+
+static ssize_t ad7816_store_channel(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf,
+ size_t len)
+{
+ struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+ struct ad7816_chip_info *chip = iio_priv(indio_dev);
+ unsigned long data;
+ int ret;
+
+ ret = kstrtoul(buf, 10, &data);
+ if (ret)
+ return ret;
+
+ if (data > AD7816_CS_MAX && data != AD7816_CS_MASK) {
+ dev_err(&chip->spi_dev->dev, "Invalid channel id %lu for %s.\n",
+ data, indio_dev->name);
+ return -EINVAL;
+ } else if (strcmp(indio_dev->name, "ad7818") == 0 && data > 1) {
+ dev_err(&chip->spi_dev->dev,
+ "Invalid channel id %lu for ad7818.\n", data);
+ return -EINVAL;
+ } else if (strcmp(indio_dev->name, "ad7816") == 0 && data > 0) {
+ dev_err(&chip->spi_dev->dev,
+ "Invalid channel id %lu for ad7816.\n", data);
+ return -EINVAL;
+ }
+
+ chip->channel_id = data;
+
+ return len;
+}
+
+static IIO_DEVICE_ATTR(channel, 0644,
+ ad7816_show_channel,
+ ad7816_store_channel,
+ 0);
+
+static ssize_t ad7816_show_value(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+ struct ad7816_chip_info *chip = iio_priv(indio_dev);
+ u16 data;
+ s8 value;
+ int ret;
+
+ ret = ad7816_spi_read(chip, &data);
+ if (ret)
+ return -EIO;
+
+ data >>= AD7816_VALUE_OFFSET;
+
+ if (chip->channel_id == 0) {
+ value = (s8)((data >> AD7816_TEMP_FLOAT_OFFSET) - 103);
+ data &= AD7816_TEMP_FLOAT_MASK;
+ if (value < 0)
+ data = BIT(AD7816_TEMP_FLOAT_OFFSET) - data;
+ return sprintf(buf, "%d.%.2d\n", value, data * 25);
+ }
+ return sprintf(buf, "%u\n", data);
+}
+
+static IIO_DEVICE_ATTR(value, 0444, ad7816_show_value, NULL, 0);
+
+static struct attribute *ad7816_attributes[] = {
+ &iio_dev_attr_available_modes.dev_attr.attr,
+ &iio_dev_attr_mode.dev_attr.attr,
+ &iio_dev_attr_channel.dev_attr.attr,
+ &iio_dev_attr_value.dev_attr.attr,
+ NULL,
+};
+
+static const struct attribute_group ad7816_attribute_group = {
+ .attrs = ad7816_attributes,
+};
+
+/*
+ * temperature bound events
+ */
+
+#define IIO_EVENT_CODE_AD7816_OTI IIO_UNMOD_EVENT_CODE(IIO_TEMP, \
+ 0, \
+ IIO_EV_TYPE_THRESH, \
+ IIO_EV_DIR_FALLING)
+
+static irqreturn_t ad7816_event_handler(int irq, void *private)
+{
+ iio_push_event(private, IIO_EVENT_CODE_AD7816_OTI,
+ iio_get_time_ns(private));
+ return IRQ_HANDLED;
+}
+
+static ssize_t ad7816_show_oti(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+ struct ad7816_chip_info *chip = iio_priv(indio_dev);
+ int value;
+
+ if (chip->channel_id > AD7816_CS_MAX) {
+ dev_err(dev, "Invalid oti channel id %d.\n", chip->channel_id);
+ return -EINVAL;
+ } else if (chip->channel_id == 0) {
+ value = AD7816_BOUND_VALUE_MIN +
+ (chip->oti_data[chip->channel_id] -
+ AD7816_BOUND_VALUE_BASE);
+ return sprintf(buf, "%d\n", value);
+ }
+ return sprintf(buf, "%u\n", chip->oti_data[chip->channel_id]);
+}
+
+static inline ssize_t ad7816_set_oti(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf,
+ size_t len)
+{
+ struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+ struct ad7816_chip_info *chip = iio_priv(indio_dev);
+ long value;
+ u8 data;
+ int ret;
+
+ ret = kstrtol(buf, 10, &value);
+ if (ret)
+ return ret;
+
+ if (chip->channel_id > AD7816_CS_MAX) {
+ dev_err(dev, "Invalid oti channel id %d.\n", chip->channel_id);
+ return -EINVAL;
+ } else if (chip->channel_id == 0) {
+ if (value < AD7816_BOUND_VALUE_MIN ||
+ value > AD7816_BOUND_VALUE_MAX)
+ return -EINVAL;
+
+ data = (u8)(value - AD7816_BOUND_VALUE_MIN +
+ AD7816_BOUND_VALUE_BASE);
+ } else {
+ if (value < AD7816_BOUND_VALUE_BASE || value > 255)
+ return -EINVAL;
+
+ data = (u8)value;
+ }
+
+ ret = ad7816_spi_write(chip, data);
+ if (ret)
+ return -EIO;
+
+ chip->oti_data[chip->channel_id] = data;
+
+ return len;
+}
+
+static IIO_DEVICE_ATTR(oti, 0644,
+ ad7816_show_oti, ad7816_set_oti, 0);
+
+static struct attribute *ad7816_event_attributes[] = {
+ &iio_dev_attr_oti.dev_attr.attr,
+ NULL,
+};
+
+static const struct attribute_group ad7816_event_attribute_group = {
+ .attrs = ad7816_event_attributes,
+ .name = "events",
+};
+
+static const struct iio_info ad7816_info = {
+ .attrs = &ad7816_attribute_group,
+ .event_attrs = &ad7816_event_attribute_group,
+};
+
+/*
+ * device probe and remove
+ */
+
+static int ad7816_probe(struct spi_device *spi_dev)
+{
+ struct ad7816_chip_info *chip;
+ struct iio_dev *indio_dev;
+ int i, ret;
+
+ indio_dev = devm_iio_device_alloc(&spi_dev->dev, sizeof(*chip));
+ if (!indio_dev)
+ return -ENOMEM;
+ chip = iio_priv(indio_dev);
+ /* this is only used for device removal purposes */
+ dev_set_drvdata(&spi_dev->dev, indio_dev);
+
+ chip->spi_dev = spi_dev;
+ for (i = 0; i <= AD7816_CS_MAX; i++)
+ chip->oti_data[i] = 203;
+
+ chip->id = spi_get_device_id(spi_dev)->driver_data;
+ chip->rdwr_pin = devm_gpiod_get(&spi_dev->dev, "rdwr", GPIOD_OUT_HIGH);
+ if (IS_ERR(chip->rdwr_pin)) {
+ ret = PTR_ERR(chip->rdwr_pin);
+ dev_err(&spi_dev->dev, "Failed to request rdwr GPIO: %d\n",
+ ret);
+ return ret;
+ }
+ chip->convert_pin = devm_gpiod_get(&spi_dev->dev, "convert",
+ GPIOD_OUT_HIGH);
+ if (IS_ERR(chip->convert_pin)) {
+ ret = PTR_ERR(chip->convert_pin);
+ dev_err(&spi_dev->dev, "Failed to request convert GPIO: %d\n",
+ ret);
+ return ret;
+ }
+ if (chip->id == ID_AD7816 || chip->id == ID_AD7817) {
+ chip->busy_pin = devm_gpiod_get(&spi_dev->dev, "busy",
+ GPIOD_IN);
+ if (IS_ERR(chip->busy_pin)) {
+ ret = PTR_ERR(chip->busy_pin);
+ dev_err(&spi_dev->dev, "Failed to request busy GPIO: %d\n",
+ ret);
+ return ret;
+ }
+ }
+
+ indio_dev->name = spi_get_device_id(spi_dev)->name;
+ indio_dev->info = &ad7816_info;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+
+ if (spi_dev->irq) {
+ /* Only low trigger is supported in ad7816/7/8 */
+ ret = devm_request_threaded_irq(&spi_dev->dev, spi_dev->irq,
+ NULL,
+ &ad7816_event_handler,
+ IRQF_TRIGGER_LOW | IRQF_ONESHOT,
+ indio_dev->name,
+ indio_dev);
+ if (ret)
+ return ret;
+ }
+
+ ret = devm_iio_device_register(&spi_dev->dev, indio_dev);
+ if (ret)
+ return ret;
+
+ dev_info(&spi_dev->dev, "%s temperature sensor and ADC registered.\n",
+ indio_dev->name);
+
+ return 0;
+}
+
+static const struct of_device_id ad7816_of_match[] = {
+ { .compatible = "adi,ad7816", },
+ { .compatible = "adi,ad7817", },
+ { .compatible = "adi,ad7818", },
+ { }
+};
+MODULE_DEVICE_TABLE(of, ad7816_of_match);
+
+static const struct spi_device_id ad7816_id[] = {
+ { "ad7816", ID_AD7816 },
+ { "ad7817", ID_AD7817 },
+ { "ad7818", ID_AD7818 },
+ {}
+};
+
+MODULE_DEVICE_TABLE(spi, ad7816_id);
+
+static struct spi_driver ad7816_driver = {
+ .driver = {
+ .name = "ad7816",
+ .of_match_table = ad7816_of_match,
+ },
+ .probe = ad7816_probe,
+ .id_table = ad7816_id,
+};
+module_spi_driver(ad7816_driver);
+
+MODULE_AUTHOR("Sonic Zhang <sonic.zhang@analog.com>");
+MODULE_DESCRIPTION("Analog Devices AD7816/7/8 digital temperature sensor driver");
+MODULE_LICENSE("GPL v2");
generated by cgit v1.2.3 (git 2.39.1) at 2024-07-19 02:07:36 +0000