123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443 |
- /*
- * AD7816 digital temperature sensor driver supporting AD7816/7/8
- *
- * Copyright 2010 Analog Devices Inc.
- *
- * Licensed under the GPL-2 or later.
- */
- #include <linux/interrupt.h>
- #include <linux/gpio.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 {
- struct spi_device *spi_dev;
- u16 rdwr_pin;
- u16 convert_pin;
- u16 busy_pin;
- u8 oti_data[AD7816_CS_MAX + 1];
- u8 channel_id; /* 0 always be temperature */
- u8 mode;
- };
- /*
- * 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 = 0;
- __be16 buf;
- gpio_set_value(chip->rdwr_pin, 1);
- gpio_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;
- }
- gpio_set_value(chip->rdwr_pin, 1);
- if (chip->mode == AD7816_PD) { /* operating mode 2 */
- gpio_set_value(chip->convert_pin, 1);
- gpio_set_value(chip->convert_pin, 0);
- } else { /* operating mode 1 */
- gpio_set_value(chip->convert_pin, 0);
- gpio_set_value(chip->convert_pin, 1);
- }
- while (gpio_get_value(chip->busy_pin))
- cpu_relax();
- gpio_set_value(chip->rdwr_pin, 0);
- gpio_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 = 0;
- gpio_set_value(chip->rdwr_pin, 1);
- gpio_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")) {
- gpio_set_value(chip->rdwr_pin, 1);
- chip->mode = AD7816_FULL;
- } else {
- gpio_set_value(chip->rdwr_pin, 0);
- chip->mode = AD7816_PD;
- }
- return len;
- }
- static IIO_DEVICE_ATTR(mode, S_IRUGO | S_IWUSR,
- 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, S_IRUGO, 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, S_IRUGO | S_IWUSR,
- 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 = (1 << 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, S_IRUGO, 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());
- 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 (ret || 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 (ret || 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, S_IRUGO | S_IWUSR,
- ad7816_show_oti, ad7816_set_oti, 0);
- static struct attribute *ad7816_event_attributes[] = {
- &iio_dev_attr_oti.dev_attr.attr,
- NULL,
- };
- static 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,
- .driver_module = THIS_MODULE,
- };
- /*
- * device probe and remove
- */
- static int ad7816_probe(struct spi_device *spi_dev)
- {
- struct ad7816_chip_info *chip;
- struct iio_dev *indio_dev;
- unsigned short *pins = spi_dev->dev.platform_data;
- int ret = 0;
- int i;
- if (!pins) {
- dev_err(&spi_dev->dev, "No necessary GPIO platform data.\n");
- return -EINVAL;
- }
- 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->rdwr_pin = pins[0];
- chip->convert_pin = pins[1];
- chip->busy_pin = pins[2];
- ret = devm_gpio_request(&spi_dev->dev, chip->rdwr_pin,
- spi_get_device_id(spi_dev)->name);
- if (ret) {
- dev_err(&spi_dev->dev, "Fail to request rdwr gpio PIN %d.\n",
- chip->rdwr_pin);
- return ret;
- }
- gpio_direction_input(chip->rdwr_pin);
- ret = devm_gpio_request(&spi_dev->dev, chip->convert_pin,
- spi_get_device_id(spi_dev)->name);
- if (ret) {
- dev_err(&spi_dev->dev, "Fail to request convert gpio PIN %d.\n",
- chip->convert_pin);
- return ret;
- }
- gpio_direction_input(chip->convert_pin);
- ret = devm_gpio_request(&spi_dev->dev, chip->busy_pin,
- spi_get_device_id(spi_dev)->name);
- if (ret) {
- dev_err(&spi_dev->dev, "Fail to request busy gpio PIN %d.\n",
- chip->busy_pin);
- return ret;
- }
- gpio_direction_input(chip->busy_pin);
- indio_dev->name = spi_get_device_id(spi_dev)->name;
- indio_dev->dev.parent = &spi_dev->dev;
- 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 spi_device_id ad7816_id[] = {
- { "ad7816", 0 },
- { "ad7817", 0 },
- { "ad7818", 0 },
- {}
- };
- MODULE_DEVICE_TABLE(spi, ad7816_id);
- static struct spi_driver ad7816_driver = {
- .driver = {
- .name = "ad7816",
- },
- .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");
|