diff options
Diffstat (limited to 'drivers/iio/dac/ad5504.c')
| -rw-r--r-- | drivers/iio/dac/ad5504.c | 393 |
1 files changed, 393 insertions, 0 deletions
diff --git a/drivers/iio/dac/ad5504.c b/drivers/iio/dac/ad5504.c new file mode 100644 index 000000000000..242bdc7d0044 --- /dev/null +++ b/drivers/iio/dac/ad5504.c @@ -0,0 +1,393 @@ +/* + * AD5504, AD5501 High Voltage Digital to Analog Converter + * + * Copyright 2011 Analog Devices Inc. + * + * Licensed under the GPL-2. + */ + +#include <linux/interrupt.h> +#include <linux/fs.h> +#include <linux/device.h> +#include <linux/kernel.h> +#include <linux/spi/spi.h> +#include <linux/slab.h> +#include <linux/sysfs.h> +#include <linux/regulator/consumer.h> +#include <linux/module.h> + +#include <linux/iio/iio.h> +#include <linux/iio/sysfs.h> +#include <linux/iio/events.h> +#include <linux/iio/dac/ad5504.h> + +#define AD5505_BITS 12 +#define AD5504_RES_MASK ((1 << (AD5505_BITS)) - 1) + +#define AD5504_CMD_READ (1 << 15) +#define AD5504_CMD_WRITE (0 << 15) +#define AD5504_ADDR(addr) ((addr) << 12) + +/* Registers */ +#define AD5504_ADDR_NOOP 0 +#define AD5504_ADDR_DAC(x) ((x) + 1) +#define AD5504_ADDR_ALL_DAC 5 +#define AD5504_ADDR_CTRL 7 + +/* Control Register */ +#define AD5504_DAC_PWR(ch) ((ch) << 2) +#define AD5504_DAC_PWRDWN_MODE(mode) ((mode) << 6) +#define AD5504_DAC_PWRDN_20K 0 +#define AD5504_DAC_PWRDN_3STATE 1 + +/** + * struct ad5446_state - driver instance specific data + * @us: spi_device + * @reg: supply regulator + * @vref_mv: actual reference voltage used + * @pwr_down_mask power down mask + * @pwr_down_mode current power down mode + */ + +struct ad5504_state { + struct spi_device *spi; + struct regulator *reg; + unsigned short vref_mv; + unsigned pwr_down_mask; + unsigned pwr_down_mode; +}; + +/** + * ad5504_supported_device_ids: + */ + +enum ad5504_supported_device_ids { + ID_AD5504, + ID_AD5501, +}; + +static int ad5504_spi_write(struct spi_device *spi, u8 addr, u16 val) +{ + u16 tmp = cpu_to_be16(AD5504_CMD_WRITE | + AD5504_ADDR(addr) | + (val & AD5504_RES_MASK)); + + return spi_write(spi, (u8 *)&tmp, 2); +} + +static int ad5504_spi_read(struct spi_device *spi, u8 addr) +{ + u16 tmp = cpu_to_be16(AD5504_CMD_READ | AD5504_ADDR(addr)); + u16 val; + int ret; + struct spi_transfer t = { + .tx_buf = &tmp, + .rx_buf = &val, + .len = 2, + }; + struct spi_message m; + + spi_message_init(&m); + spi_message_add_tail(&t, &m); + ret = spi_sync(spi, &m); + + if (ret < 0) + return ret; + + return be16_to_cpu(val) & AD5504_RES_MASK; +} + +static int ad5504_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, + int *val2, + long m) +{ + struct ad5504_state *st = iio_priv(indio_dev); + unsigned long scale_uv; + int ret; + + switch (m) { + case IIO_CHAN_INFO_RAW: + ret = ad5504_spi_read(st->spi, chan->address); + if (ret < 0) + return ret; + + *val = ret; + + return IIO_VAL_INT; + case IIO_CHAN_INFO_SCALE: + scale_uv = (st->vref_mv * 1000) >> chan->scan_type.realbits; + *val = scale_uv / 1000; + *val2 = (scale_uv % 1000) * 1000; + return IIO_VAL_INT_PLUS_MICRO; + + } + return -EINVAL; +} + +static int ad5504_write_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int val, + int val2, + long mask) +{ + struct ad5504_state *st = iio_priv(indio_dev); + int ret; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + if (val >= (1 << chan->scan_type.realbits) || val < 0) + return -EINVAL; + + return ad5504_spi_write(st->spi, chan->address, val); + default: + ret = -EINVAL; + } + + return -EINVAL; +} + +static const char * const ad5504_powerdown_modes[] = { + "20kohm_to_gnd", + "three_state", +}; + +static int ad5504_get_powerdown_mode(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan) +{ + struct ad5504_state *st = iio_priv(indio_dev); + + return st->pwr_down_mode; +} + +static int ad5504_set_powerdown_mode(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan, unsigned int mode) +{ + struct ad5504_state *st = iio_priv(indio_dev); + + st->pwr_down_mode = mode; + + return 0; +} + +static const struct iio_enum ad5504_powerdown_mode_enum = { + .items = ad5504_powerdown_modes, + .num_items = ARRAY_SIZE(ad5504_powerdown_modes), + .get = ad5504_get_powerdown_mode, + .set = ad5504_set_powerdown_mode, +}; + +static ssize_t ad5504_read_dac_powerdown(struct iio_dev *indio_dev, + uintptr_t private, const struct iio_chan_spec *chan, char *buf) +{ + struct ad5504_state *st = iio_priv(indio_dev); + + return sprintf(buf, "%d\n", + !(st->pwr_down_mask & (1 << chan->channel))); +} + +static ssize_t ad5504_write_dac_powerdown(struct iio_dev *indio_dev, + uintptr_t private, const struct iio_chan_spec *chan, const char *buf, + size_t len) +{ + bool pwr_down; + int ret; + struct ad5504_state *st = iio_priv(indio_dev); + + ret = strtobool(buf, &pwr_down); + if (ret) + return ret; + + if (pwr_down) + st->pwr_down_mask |= (1 << chan->channel); + else + st->pwr_down_mask &= ~(1 << chan->channel); + + ret = ad5504_spi_write(st->spi, AD5504_ADDR_CTRL, + AD5504_DAC_PWRDWN_MODE(st->pwr_down_mode) | + AD5504_DAC_PWR(st->pwr_down_mask)); + + /* writes to the CTRL register must be followed by a NOOP */ + ad5504_spi_write(st->spi, AD5504_ADDR_NOOP, 0); + + return ret ? ret : len; +} + +static IIO_CONST_ATTR(temp0_thresh_rising_value, "110000"); +static IIO_CONST_ATTR(temp0_thresh_rising_en, "1"); + +static struct attribute *ad5504_ev_attributes[] = { + &iio_const_attr_temp0_thresh_rising_value.dev_attr.attr, + &iio_const_attr_temp0_thresh_rising_en.dev_attr.attr, + NULL, +}; + +static struct attribute_group ad5504_ev_attribute_group = { + .attrs = ad5504_ev_attributes, + .name = "events", +}; + +static irqreturn_t ad5504_event_handler(int irq, void *private) +{ + iio_push_event(private, + IIO_UNMOD_EVENT_CODE(IIO_TEMP, + 0, + IIO_EV_TYPE_THRESH, + IIO_EV_DIR_RISING), + iio_get_time_ns()); + + return IRQ_HANDLED; +} + +static const struct iio_info ad5504_info = { + .write_raw = ad5504_write_raw, + .read_raw = ad5504_read_raw, + .event_attrs = &ad5504_ev_attribute_group, + .driver_module = THIS_MODULE, +}; + +static const struct iio_chan_spec_ext_info ad5504_ext_info[] = { + { + .name = "powerdown", + .read = ad5504_read_dac_powerdown, + .write = ad5504_write_dac_powerdown, + }, + IIO_ENUM("powerdown_mode", true, &ad5504_powerdown_mode_enum), + IIO_ENUM_AVAILABLE("powerdown_mode", &ad5504_powerdown_mode_enum), + { }, +}; + +#define AD5504_CHANNEL(_chan) { \ + .type = IIO_VOLTAGE, \ + .indexed = 1, \ + .output = 1, \ + .channel = (_chan), \ + .info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT | \ + IIO_CHAN_INFO_SCALE_SHARED_BIT, \ + .address = AD5504_ADDR_DAC(_chan), \ + .scan_type = IIO_ST('u', 12, 16, 0), \ + .ext_info = ad5504_ext_info, \ +} + +static const struct iio_chan_spec ad5504_channels[] = { + AD5504_CHANNEL(0), + AD5504_CHANNEL(1), + AD5504_CHANNEL(2), + AD5504_CHANNEL(3), +}; + +static int __devinit ad5504_probe(struct spi_device *spi) +{ + struct ad5504_platform_data *pdata = spi->dev.platform_data; + struct iio_dev *indio_dev; + struct ad5504_state *st; + struct regulator *reg; + int ret, voltage_uv = 0; + + indio_dev = iio_device_alloc(sizeof(*st)); + if (indio_dev == NULL) { + ret = -ENOMEM; + goto error_ret; + } + reg = regulator_get(&spi->dev, "vcc"); + if (!IS_ERR(reg)) { + ret = regulator_enable(reg); + if (ret) + goto error_put_reg; + + voltage_uv = regulator_get_voltage(reg); + } + + spi_set_drvdata(spi, indio_dev); + st = iio_priv(indio_dev); + if (voltage_uv) + st->vref_mv = voltage_uv / 1000; + else if (pdata) + st->vref_mv = pdata->vref_mv; + else + dev_warn(&spi->dev, "reference voltage unspecified\n"); + + st->reg = reg; + st->spi = spi; + indio_dev->dev.parent = &spi->dev; + indio_dev->name = spi_get_device_id(st->spi)->name; + indio_dev->info = &ad5504_info; + if (spi_get_device_id(st->spi)->driver_data == ID_AD5501) + indio_dev->num_channels = 1; + else + indio_dev->num_channels = 4; + indio_dev->channels = ad5504_channels; + indio_dev->modes = INDIO_DIRECT_MODE; + + if (spi->irq) { + ret = request_threaded_irq(spi->irq, + NULL, + &ad5504_event_handler, + IRQF_TRIGGER_FALLING | IRQF_ONESHOT, + spi_get_device_id(st->spi)->name, + indio_dev); + if (ret) + goto error_disable_reg; + } + + ret = iio_device_register(indio_dev); + if (ret) + goto error_free_irq; + + return 0; + +error_free_irq: + if (spi->irq) + free_irq(spi->irq, indio_dev); +error_disable_reg: + if (!IS_ERR(reg)) + regulator_disable(reg); +error_put_reg: + if (!IS_ERR(reg)) + regulator_put(reg); + + iio_device_free(indio_dev); +error_ret: + return ret; +} + +static int __devexit ad5504_remove(struct spi_device *spi) +{ + struct iio_dev *indio_dev = spi_get_drvdata(spi); + struct ad5504_state *st = iio_priv(indio_dev); + + iio_device_unregister(indio_dev); + if (spi->irq) + free_irq(spi->irq, indio_dev); + + if (!IS_ERR(st->reg)) { + regulator_disable(st->reg); + regulator_put(st->reg); + } + iio_device_free(indio_dev); + + return 0; +} + +static const struct spi_device_id ad5504_id[] = { + {"ad5504", ID_AD5504}, + {"ad5501", ID_AD5501}, + {} +}; +MODULE_DEVICE_TABLE(spi, ad5504_id); + +static struct spi_driver ad5504_driver = { + .driver = { + .name = "ad5504", + .owner = THIS_MODULE, + }, + .probe = ad5504_probe, + .remove = __devexit_p(ad5504_remove), + .id_table = ad5504_id, +}; +module_spi_driver(ad5504_driver); + +MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>"); +MODULE_DESCRIPTION("Analog Devices AD5501/AD5501 DAC"); +MODULE_LICENSE("GPL v2"); |