diff options
Diffstat (limited to 'drivers/staging/iio/dac/ad5421.c')
| -rw-r--r-- | drivers/staging/iio/dac/ad5421.c | 545 |
1 files changed, 0 insertions, 545 deletions
diff --git a/drivers/staging/iio/dac/ad5421.c b/drivers/staging/iio/dac/ad5421.c deleted file mode 100644 index ffbd4c234f57..000000000000 --- a/drivers/staging/iio/dac/ad5421.c +++ /dev/null @@ -1,545 +0,0 @@ -/* - * AD5421 Digital to analog converters driver - * - * Copyright 2011 Analog Devices Inc. - * - * Licensed under the GPL-2. - */ - -#include <linux/device.h> -#include <linux/delay.h> -#include <linux/err.h> -#include <linux/module.h> -#include <linux/interrupt.h> -#include <linux/kernel.h> -#include <linux/spi/spi.h> -#include <linux/slab.h> -#include <linux/sysfs.h> - -#include <linux/iio/iio.h> -#include <linux/iio/sysfs.h> -#include <linux/iio/events.h> -#include "dac.h" -#include "ad5421.h" - - -#define AD5421_REG_DAC_DATA 0x1 -#define AD5421_REG_CTRL 0x2 -#define AD5421_REG_OFFSET 0x3 -#define AD5421_REG_GAIN 0x4 -/* load dac and fault shared the same register number. Writing to it will cause - * a dac load command, reading from it will return the fault status register */ -#define AD5421_REG_LOAD_DAC 0x5 -#define AD5421_REG_FAULT 0x5 -#define AD5421_REG_FORCE_ALARM_CURRENT 0x6 -#define AD5421_REG_RESET 0x7 -#define AD5421_REG_START_CONVERSION 0x8 -#define AD5421_REG_NOOP 0x9 - -#define AD5421_CTRL_WATCHDOG_DISABLE BIT(12) -#define AD5421_CTRL_AUTO_FAULT_READBACK BIT(11) -#define AD5421_CTRL_MIN_CURRENT BIT(9) -#define AD5421_CTRL_ADC_SOURCE_TEMP BIT(8) -#define AD5421_CTRL_ADC_ENABLE BIT(7) -#define AD5421_CTRL_PWR_DOWN_INT_VREF BIT(6) - -#define AD5421_FAULT_SPI BIT(15) -#define AD5421_FAULT_PEC BIT(14) -#define AD5421_FAULT_OVER_CURRENT BIT(13) -#define AD5421_FAULT_UNDER_CURRENT BIT(12) -#define AD5421_FAULT_TEMP_OVER_140 BIT(11) -#define AD5421_FAULT_TEMP_OVER_100 BIT(10) -#define AD5421_FAULT_UNDER_VOLTAGE_6V BIT(9) -#define AD5421_FAULT_UNDER_VOLTAGE_12V BIT(8) - -/* These bits will cause the fault pin to go high */ -#define AD5421_FAULT_TRIGGER_IRQ \ - (AD5421_FAULT_SPI | AD5421_FAULT_PEC | AD5421_FAULT_OVER_CURRENT | \ - AD5421_FAULT_UNDER_CURRENT | AD5421_FAULT_TEMP_OVER_140) - -/** - * struct ad5421_state - driver instance specific data - * @spi: spi_device - * @ctrl: control register cache - * @current_range: current range which the device is configured for - * @data: spi transfer buffers - * @fault_mask: software masking of events - */ -struct ad5421_state { - struct spi_device *spi; - unsigned int ctrl; - enum ad5421_current_range current_range; - unsigned int fault_mask; - - /* - * DMA (thus cache coherency maintenance) requires the - * transfer buffers to live in their own cache lines. - */ - union { - u32 d32; - u8 d8[4]; - } data[2] ____cacheline_aligned; -}; - -static const struct iio_chan_spec ad5421_channels[] = { - { - .type = IIO_CURRENT, - .indexed = 1, - .output = 1, - .channel = 0, - .info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT | - IIO_CHAN_INFO_SCALE_SHARED_BIT | - IIO_CHAN_INFO_OFFSET_SHARED_BIT | - IIO_CHAN_INFO_CALIBSCALE_SEPARATE_BIT | - IIO_CHAN_INFO_CALIBBIAS_SEPARATE_BIT, - .scan_type = IIO_ST('u', 16, 16, 0), - .event_mask = IIO_EV_BIT(IIO_EV_TYPE_THRESH, IIO_EV_DIR_RISING) | - IIO_EV_BIT(IIO_EV_TYPE_THRESH, IIO_EV_DIR_FALLING), - }, - { - .type = IIO_TEMP, - .channel = -1, - .event_mask = IIO_EV_BIT(IIO_EV_TYPE_THRESH, IIO_EV_DIR_RISING), - }, -}; - -static int ad5421_write_unlocked(struct iio_dev *indio_dev, - unsigned int reg, unsigned int val) -{ - struct ad5421_state *st = iio_priv(indio_dev); - - st->data[0].d32 = cpu_to_be32((reg << 16) | val); - - return spi_write(st->spi, &st->data[0].d8[1], 3); -} - -static int ad5421_write(struct iio_dev *indio_dev, unsigned int reg, - unsigned int val) -{ - int ret; - - mutex_lock(&indio_dev->mlock); - ret = ad5421_write_unlocked(indio_dev, reg, val); - mutex_unlock(&indio_dev->mlock); - - return ret; -} - -static int ad5421_read(struct iio_dev *indio_dev, unsigned int reg) -{ - struct ad5421_state *st = iio_priv(indio_dev); - struct spi_message m; - int ret; - struct spi_transfer t[] = { - { - .tx_buf = &st->data[0].d8[1], - .len = 3, - .cs_change = 1, - }, { - .rx_buf = &st->data[1].d8[1], - .len = 3, - }, - }; - - spi_message_init(&m); - spi_message_add_tail(&t[0], &m); - spi_message_add_tail(&t[1], &m); - - mutex_lock(&indio_dev->mlock); - - st->data[0].d32 = cpu_to_be32((1 << 23) | (reg << 16)); - - ret = spi_sync(st->spi, &m); - if (ret >= 0) - ret = be32_to_cpu(st->data[1].d32) & 0xffff; - - mutex_unlock(&indio_dev->mlock); - - return ret; -} - -static int ad5421_update_ctrl(struct iio_dev *indio_dev, unsigned int set, - unsigned int clr) -{ - struct ad5421_state *st = iio_priv(indio_dev); - unsigned int ret; - - mutex_lock(&indio_dev->mlock); - - st->ctrl &= ~clr; - st->ctrl |= set; - - ret = ad5421_write_unlocked(indio_dev, AD5421_REG_CTRL, st->ctrl); - - mutex_unlock(&indio_dev->mlock); - - return ret; -} - -static irqreturn_t ad5421_fault_handler(int irq, void *data) -{ - struct iio_dev *indio_dev = data; - struct ad5421_state *st = iio_priv(indio_dev); - unsigned int fault; - unsigned int old_fault = 0; - unsigned int events; - - fault = ad5421_read(indio_dev, AD5421_REG_FAULT); - if (!fault) - return IRQ_NONE; - - /* If we had a fault, this might mean that the DAC has lost its state - * and has been reset. Make sure that the control register actually - * contains what we expect it to contain. Otherwise the watchdog might - * be enabled and we get watchdog timeout faults, which will render the - * DAC unusable. */ - ad5421_update_ctrl(indio_dev, 0, 0); - - - /* The fault pin stays high as long as a fault condition is present and - * it is not possible to mask fault conditions. For certain fault - * conditions for example like over-temperature it takes some time - * until the fault condition disappears. If we would exit the interrupt - * handler immediately after handling the event it would be entered - * again instantly. Thus we fall back to polling in case we detect that - * a interrupt condition is still present. - */ - do { - /* 0xffff is a invalid value for the register and will only be - * read if there has been a communication error */ - if (fault == 0xffff) - fault = 0; - - /* we are only interested in new events */ - events = (old_fault ^ fault) & fault; - events &= st->fault_mask; - - if (events & AD5421_FAULT_OVER_CURRENT) { - iio_push_event(indio_dev, - IIO_UNMOD_EVENT_CODE(IIO_CURRENT, - 0, - IIO_EV_TYPE_THRESH, - IIO_EV_DIR_RISING), - iio_get_time_ns()); - } - - if (events & AD5421_FAULT_UNDER_CURRENT) { - iio_push_event(indio_dev, - IIO_UNMOD_EVENT_CODE(IIO_CURRENT, - 0, - IIO_EV_TYPE_THRESH, - IIO_EV_DIR_FALLING), - iio_get_time_ns()); - } - - if (events & AD5421_FAULT_TEMP_OVER_140) { - iio_push_event(indio_dev, - IIO_UNMOD_EVENT_CODE(IIO_TEMP, - 0, - IIO_EV_TYPE_MAG, - IIO_EV_DIR_RISING), - iio_get_time_ns()); - } - - old_fault = fault; - fault = ad5421_read(indio_dev, AD5421_REG_FAULT); - - /* still active? go to sleep for some time */ - if (fault & AD5421_FAULT_TRIGGER_IRQ) - msleep(1000); - - } while (fault & AD5421_FAULT_TRIGGER_IRQ); - - - return IRQ_HANDLED; -} - -static void ad5421_get_current_min_max(struct ad5421_state *st, - unsigned int *min, unsigned int *max) -{ - /* The current range is configured using external pins, which are - * usually hard-wired and not run-time switchable. */ - switch (st->current_range) { - case AD5421_CURRENT_RANGE_4mA_20mA: - *min = 4000; - *max = 20000; - break; - case AD5421_CURRENT_RANGE_3mA8_21mA: - *min = 3800; - *max = 21000; - break; - case AD5421_CURRENT_RANGE_3mA2_24mA: - *min = 3200; - *max = 24000; - break; - default: - *min = 0; - *max = 1; - break; - } -} - -static inline unsigned int ad5421_get_offset(struct ad5421_state *st) -{ - unsigned int min, max; - - ad5421_get_current_min_max(st, &min, &max); - return (min * (1 << 16)) / (max - min); -} - -static inline unsigned int ad5421_get_scale(struct ad5421_state *st) -{ - unsigned int min, max; - - ad5421_get_current_min_max(st, &min, &max); - return ((max - min) * 1000) / (1 << 16); -} - -static int ad5421_read_raw(struct iio_dev *indio_dev, - struct iio_chan_spec const *chan, int *val, int *val2, long m) -{ - struct ad5421_state *st = iio_priv(indio_dev); - int ret; - - if (chan->type != IIO_CURRENT) - return -EINVAL; - - switch (m) { - case IIO_CHAN_INFO_RAW: - ret = ad5421_read(indio_dev, AD5421_REG_DAC_DATA); - if (ret < 0) - return ret; - *val = ret; - return IIO_VAL_INT; - case IIO_CHAN_INFO_SCALE: - *val = 0; - *val2 = ad5421_get_scale(st); - return IIO_VAL_INT_PLUS_MICRO; - case IIO_CHAN_INFO_OFFSET: - *val = ad5421_get_offset(st); - return IIO_VAL_INT; - case IIO_CHAN_INFO_CALIBBIAS: - ret = ad5421_read(indio_dev, AD5421_REG_OFFSET); - if (ret < 0) - return ret; - *val = ret - 32768; - return IIO_VAL_INT; - case IIO_CHAN_INFO_CALIBSCALE: - ret = ad5421_read(indio_dev, AD5421_REG_GAIN); - if (ret < 0) - return ret; - *val = ret; - return IIO_VAL_INT; - } - - return -EINVAL; -} - -static int ad5421_write_raw(struct iio_dev *indio_dev, - struct iio_chan_spec const *chan, int val, int val2, long mask) -{ - const unsigned int max_val = 1 << 16; - - switch (mask) { - case IIO_CHAN_INFO_RAW: - if (val >= max_val || val < 0) - return -EINVAL; - - return ad5421_write(indio_dev, AD5421_REG_DAC_DATA, val); - case IIO_CHAN_INFO_CALIBBIAS: - val += 32768; - if (val >= max_val || val < 0) - return -EINVAL; - - return ad5421_write(indio_dev, AD5421_REG_OFFSET, val); - case IIO_CHAN_INFO_CALIBSCALE: - if (val >= max_val || val < 0) - return -EINVAL; - - return ad5421_write(indio_dev, AD5421_REG_GAIN, val); - default: - break; - } - - return -EINVAL; -} - -static int ad5421_write_event_config(struct iio_dev *indio_dev, - u64 event_code, int state) -{ - struct ad5421_state *st = iio_priv(indio_dev); - unsigned int mask; - - switch (IIO_EVENT_CODE_EXTRACT_CHAN_TYPE(event_code)) { - case IIO_CURRENT: - if (IIO_EVENT_CODE_EXTRACT_DIR(event_code) == - IIO_EV_DIR_RISING) - mask = AD5421_FAULT_OVER_CURRENT; - else - mask = AD5421_FAULT_UNDER_CURRENT; - break; - case IIO_TEMP: - mask = AD5421_FAULT_TEMP_OVER_140; - break; - default: - return -EINVAL; - } - - mutex_lock(&indio_dev->mlock); - if (state) - st->fault_mask |= mask; - else - st->fault_mask &= ~mask; - mutex_unlock(&indio_dev->mlock); - - return 0; -} - -static int ad5421_read_event_config(struct iio_dev *indio_dev, - u64 event_code) -{ - struct ad5421_state *st = iio_priv(indio_dev); - unsigned int mask; - - switch (IIO_EVENT_CODE_EXTRACT_CHAN_TYPE(event_code)) { - case IIO_CURRENT: - if (IIO_EVENT_CODE_EXTRACT_DIR(event_code) == - IIO_EV_DIR_RISING) - mask = AD5421_FAULT_OVER_CURRENT; - else - mask = AD5421_FAULT_UNDER_CURRENT; - break; - case IIO_TEMP: - mask = AD5421_FAULT_TEMP_OVER_140; - break; - default: - return -EINVAL; - } - - return (bool)(st->fault_mask & mask); -} - -static int ad5421_read_event_value(struct iio_dev *indio_dev, u64 event_code, - int *val) -{ - int ret; - - switch (IIO_EVENT_CODE_EXTRACT_CHAN_TYPE(event_code)) { - case IIO_CURRENT: - ret = ad5421_read(indio_dev, AD5421_REG_DAC_DATA); - if (ret < 0) - return ret; - *val = ret; - break; - case IIO_TEMP: - *val = 140000; - break; - default: - return -EINVAL; - } - - return 0; -} - -static const struct iio_info ad5421_info = { - .read_raw = ad5421_read_raw, - .write_raw = ad5421_write_raw, - .read_event_config = ad5421_read_event_config, - .write_event_config = ad5421_write_event_config, - .read_event_value = ad5421_read_event_value, - .driver_module = THIS_MODULE, -}; - -static int __devinit ad5421_probe(struct spi_device *spi) -{ - struct ad5421_platform_data *pdata = dev_get_platdata(&spi->dev); - struct iio_dev *indio_dev; - struct ad5421_state *st; - int ret; - - indio_dev = iio_device_alloc(sizeof(*st)); - if (indio_dev == NULL) { - dev_err(&spi->dev, "Failed to allocate iio device\n"); - return -ENOMEM; - } - - st = iio_priv(indio_dev); - spi_set_drvdata(spi, indio_dev); - - st->spi = spi; - - indio_dev->dev.parent = &spi->dev; - indio_dev->name = "ad5421"; - indio_dev->info = &ad5421_info; - indio_dev->modes = INDIO_DIRECT_MODE; - indio_dev->channels = ad5421_channels; - indio_dev->num_channels = ARRAY_SIZE(ad5421_channels); - - st->ctrl = AD5421_CTRL_WATCHDOG_DISABLE | - AD5421_CTRL_AUTO_FAULT_READBACK; - - if (pdata) { - st->current_range = pdata->current_range; - if (pdata->external_vref) - st->ctrl |= AD5421_CTRL_PWR_DOWN_INT_VREF; - } else { - st->current_range = AD5421_CURRENT_RANGE_4mA_20mA; - } - - /* write initial ctrl register value */ - ad5421_update_ctrl(indio_dev, 0, 0); - - if (spi->irq) { - ret = request_threaded_irq(spi->irq, - NULL, - ad5421_fault_handler, - IRQF_TRIGGER_HIGH | IRQF_ONESHOT, - "ad5421 fault", - indio_dev); - if (ret) - goto error_free; - } - - ret = iio_device_register(indio_dev); - if (ret) { - dev_err(&spi->dev, "Failed to register iio device: %d\n", ret); - goto error_free_irq; - } - - return 0; - -error_free_irq: - if (spi->irq) - free_irq(spi->irq, indio_dev); -error_free: - iio_device_free(indio_dev); - - return ret; -} - -static int __devexit ad5421_remove(struct spi_device *spi) -{ - struct iio_dev *indio_dev = spi_get_drvdata(spi); - - iio_device_unregister(indio_dev); - if (spi->irq) - free_irq(spi->irq, indio_dev); - iio_device_free(indio_dev); - - return 0; -} - -static struct spi_driver ad5421_driver = { - .driver = { - .name = "ad5421", - .owner = THIS_MODULE, - }, - .probe = ad5421_probe, - .remove = __devexit_p(ad5421_remove), -}; -module_spi_driver(ad5421_driver); - -MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>"); -MODULE_DESCRIPTION("Analog Devices AD5421 DAC"); -MODULE_LICENSE("GPL v2"); -MODULE_ALIAS("spi:ad5421"); |