From 7924425db04a6107e49312edf53c158590d52aae Mon Sep 17 00:00:00 2001 From: Sonic Zhang Date: Wed, 27 Oct 2010 21:43:59 -0400 Subject: [PATCH] staging: iio: adc: new driver for AD7816 devices Signed-off-by: Sonic Zhang Signed-off-by: Michael Hennerich Acked-by: Jonathan Cameron Signed-off-by: Mike Frysinger Signed-off-by: Greg Kroah-Hartman --- drivers/staging/iio/adc/Kconfig | 7 + drivers/staging/iio/adc/Makefile | 1 + drivers/staging/iio/adc/ad7816.c | 535 +++++++++++++++++++++++++++++++ 3 files changed, 543 insertions(+) create mode 100644 drivers/staging/iio/adc/ad7816.c diff --git a/drivers/staging/iio/adc/Kconfig b/drivers/staging/iio/adc/Kconfig index 34c6822ae070..e722b26ee197 100644 --- a/drivers/staging/iio/adc/Kconfig +++ b/drivers/staging/iio/adc/Kconfig @@ -106,3 +106,10 @@ config AD7745 To compile this driver as a module, choose M here: the module will be called ad7745. + +config AD7816 + tristate "Analog Devices AD7816/7/8 temperature sensor and ADC driver" + depends on SPI + help + Say yes here to build support for Analog Devices AD7816/7/8 + temperature sensors and ADC. diff --git a/drivers/staging/iio/adc/Makefile b/drivers/staging/iio/adc/Makefile index ac83bad5125a..b8d641cca1d2 100644 --- a/drivers/staging/iio/adc/Makefile +++ b/drivers/staging/iio/adc/Makefile @@ -21,3 +21,4 @@ obj-$(CONFIG_AD7291) += ad7291.o obj-$(CONFIG_AD7298) += ad7298.o obj-$(CONFIG_AD7314) += ad7314.o obj-$(CONFIG_AD7745) += ad7745.o +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 000000000000..ad7415a6b8d9 --- /dev/null +++ b/drivers/staging/iio/adc/ad7816.c @@ -0,0 +1,535 @@ +/* + * AD7816 digital temperature sensor driver supporting AD7816/7/8 + * + * Copyright 2010 Analog Devices Inc. + * + * Licensed under the GPL-2 or later. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "../iio.h" +#include "../sysfs.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 specifc information + */ + +struct ad7816_chip_info { + const char *name; + struct spi_device *spi_dev; + struct iio_dev *indio_dev; + struct work_struct thresh_work; + s64 last_timestamp; + 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; + + 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, (u8 *)data, sizeof(*data)); + if (ret < 0) { + dev_err(&spi_dev->dev, "SPI data read error\n"); + return ret; + } + + *data = be16_to_cpu(*data); + + 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 *dev_info = dev_get_drvdata(dev); + struct ad7816_chip_info *chip = dev_info->dev_data; + + if (chip->mode) + return sprintf(buf, "power-save\n"); + else + 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 *dev_info = dev_get_drvdata(dev); + struct ad7816_chip_info *chip = dev_info->dev_data; + + 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 *dev_info = dev_get_drvdata(dev); + struct ad7816_chip_info *chip = dev_info->dev_data; + + 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 *dev_info = dev_get_drvdata(dev); + struct ad7816_chip_info *chip = dev_info->dev_data; + unsigned long data; + int ret; + + ret = strict_strtoul(buf, 10, &data); + if (ret) + return -EINVAL; + + if (data > AD7816_CS_MAX && data != AD7816_CS_MASK) { + dev_err(&chip->spi_dev->dev, "Invalid channel id %lu for %s.\n", + data, chip->name); + return -EINVAL; + } else if (strcmp(chip->name, "ad7818") == 0 && data > 1) { + dev_err(&chip->spi_dev->dev, + "Invalid channel id %lu for ad7818.\n", data); + return -EINVAL; + } else if (strcmp(chip->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 *dev_info = dev_get_drvdata(dev); + struct ad7816_chip_info *chip = dev_info->dev_data; + 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); + } else + return sprintf(buf, "%u\n", data); +} + +static IIO_DEVICE_ATTR(value, S_IRUGO, ad7816_show_value, NULL, 0); + +static ssize_t ad7816_show_name(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct iio_dev *dev_info = dev_get_drvdata(dev); + struct ad7816_chip_info *chip = dev_info->dev_data; + return sprintf(buf, "%s\n", chip->name); +} + +static IIO_DEVICE_ATTR(name, S_IRUGO, ad7816_show_name, 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, + &iio_dev_attr_name.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_BUFFER_EVENT_CODE(0) + +static void ad7816_interrupt_bh(struct work_struct *work_s) +{ + struct ad7816_chip_info *chip = + container_of(work_s, struct ad7816_chip_info, thresh_work); + + enable_irq(chip->spi_dev->irq); + + iio_push_event(chip->indio_dev, 0, + IIO_EVENT_CODE_AD7816_OTI, + chip->last_timestamp); +} + +static int ad7816_interrupt(struct iio_dev *dev_info, + int index, + s64 timestamp, + int no_test) +{ + struct ad7816_chip_info *chip = dev_info->dev_data; + + chip->last_timestamp = timestamp; + schedule_work(&chip->thresh_work); + + return 0; +} + +IIO_EVENT_SH(ad7816, &ad7816_interrupt); + +static ssize_t ad7816_show_oti(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct iio_dev *dev_info = dev_get_drvdata(dev); + struct ad7816_chip_info *chip = dev_info->dev_data; + 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); + } else + 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 *dev_info = dev_get_drvdata(dev); + struct ad7816_chip_info *chip = dev_info->dev_data; + long value; + u8 data; + int ret; + + ret = strict_strtol(buf, 10, &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) { + 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; +} + +IIO_EVENT_ATTR_SH(oti, iio_event_ad7816, + ad7816_show_oti, ad7816_set_oti, 0); + +static struct attribute *ad7816_event_attributes[] = { + &iio_event_attr_oti.dev_attr.attr, + NULL, +}; + +static struct attribute_group ad7816_event_attribute_group = { + .attrs = ad7816_event_attributes, +}; + +/* + * device probe and remove + */ + +static int __devinit ad7816_probe(struct spi_device *spi_dev) +{ + struct ad7816_chip_info *chip; + 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; + } + + chip = kzalloc(sizeof(struct ad7816_chip_info), GFP_KERNEL); + + if (chip == NULL) + return -ENOMEM; + + /* this is only used for device removal purposes */ + dev_set_drvdata(&spi_dev->dev, chip); + + chip->spi_dev = spi_dev; + chip->name = spi_dev->modalias; + 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 = gpio_request(chip->rdwr_pin, chip->name); + if (ret) { + dev_err(&spi_dev->dev, "Fail to request rdwr gpio PIN %d.\n", + chip->rdwr_pin); + goto error_free_chip; + } + gpio_direction_input(chip->rdwr_pin); + ret = gpio_request(chip->convert_pin, chip->name); + if (ret) { + dev_err(&spi_dev->dev, "Fail to request convert gpio PIN %d.\n", + chip->convert_pin); + goto error_free_gpio_rdwr; + } + gpio_direction_input(chip->convert_pin); + ret = gpio_request(chip->busy_pin, chip->name); + if (ret) { + dev_err(&spi_dev->dev, "Fail to request busy gpio PIN %d.\n", + chip->busy_pin); + goto error_free_gpio_convert; + } + gpio_direction_input(chip->busy_pin); + + chip->indio_dev = iio_allocate_device(); + if (chip->indio_dev == NULL) { + ret = -ENOMEM; + goto error_free_gpio; + } + + chip->indio_dev->dev.parent = &spi_dev->dev; + chip->indio_dev->attrs = &ad7816_attribute_group; + chip->indio_dev->event_attrs = &ad7816_event_attribute_group; + chip->indio_dev->dev_data = (void *)chip; + chip->indio_dev->driver_module = THIS_MODULE; + chip->indio_dev->num_interrupt_lines = 1; + chip->indio_dev->modes = INDIO_DIRECT_MODE; + + ret = iio_device_register(chip->indio_dev); + if (ret) + goto error_free_dev; + + if (spi_dev->irq) { + /* Only low trigger is supported in ad7816/7/8 */ + ret = iio_register_interrupt_line(spi_dev->irq, + chip->indio_dev, + 0, + IRQF_TRIGGER_LOW, + chip->name); + if (ret) + goto error_unreg_dev; + + /* + * The event handler list element refer to iio_event_ad7816. + * All event attributes bind to the same event handler. + * So, only register event handler once. + */ + iio_add_event_to_list(&iio_event_ad7816, + &chip->indio_dev->interrupts[0]->ev_list); + + INIT_WORK(&chip->thresh_work, ad7816_interrupt_bh); + } + + dev_info(&spi_dev->dev, "%s temperature sensor and ADC registered.\n", + chip->name); + + return 0; + +error_unreg_dev: + iio_device_unregister(chip->indio_dev); +error_free_dev: + iio_free_device(chip->indio_dev); +error_free_gpio: + gpio_free(chip->busy_pin); +error_free_gpio_convert: + gpio_free(chip->convert_pin); +error_free_gpio_rdwr: + gpio_free(chip->rdwr_pin); +error_free_chip: + kfree(chip); + + return ret; +} + +static int __devexit ad7816_remove(struct spi_device *spi_dev) +{ + struct ad7816_chip_info *chip = dev_get_drvdata(&spi_dev->dev); + struct iio_dev *indio_dev = chip->indio_dev; + + dev_set_drvdata(&spi_dev->dev, NULL); + if (spi_dev->irq) + iio_unregister_interrupt_line(indio_dev, 0); + iio_device_unregister(indio_dev); + iio_free_device(chip->indio_dev); + gpio_free(chip->busy_pin); + gpio_free(chip->convert_pin); + gpio_free(chip->rdwr_pin); + kfree(chip); + + 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", + .bus = &spi_bus_type, + .owner = THIS_MODULE, + }, + .probe = ad7816_probe, + .remove = __devexit_p(ad7816_remove), + .id_table = ad7816_id, +}; + +static __init int ad7816_init(void) +{ + return spi_register_driver(&ad7816_driver); +} + +static __exit void ad7816_exit(void) +{ + spi_unregister_driver(&ad7816_driver); +} + +MODULE_AUTHOR("Sonic Zhang "); +MODULE_DESCRIPTION("Analog Devices AD7816/7/8 digital" + " temperature sensor driver"); +MODULE_LICENSE("GPL v2"); + +module_init(ad7816_init); +module_exit(ad7816_exit); -- 2.20.1