diff options
Diffstat (limited to 'drivers/iio/dac/ad5360.c')
-rw-r--r-- | drivers/iio/dac/ad5360.c | 560 |
1 files changed, 560 insertions, 0 deletions
diff --git a/drivers/iio/dac/ad5360.c b/drivers/iio/dac/ad5360.c new file mode 100644 index 000000000..0209316d5 --- /dev/null +++ b/drivers/iio/dac/ad5360.c @@ -0,0 +1,560 @@ +/* + * Analog devices AD5360, AD5361, AD5362, AD5363, AD5370, AD5371, AD5373 + * multi-channel Digital to Analog Converters driver + * + * Copyright 2011 Analog Devices Inc. + * + * Licensed under the GPL-2. + */ + +#include <linux/device.h> +#include <linux/err.h> +#include <linux/module.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/iio/iio.h> +#include <linux/iio/sysfs.h> + +#define AD5360_CMD(x) ((x) << 22) +#define AD5360_ADDR(x) ((x) << 16) + +#define AD5360_READBACK_TYPE(x) ((x) << 13) +#define AD5360_READBACK_ADDR(x) ((x) << 7) + +#define AD5360_CHAN_ADDR(chan) ((chan) + 0x8) + +#define AD5360_CMD_WRITE_DATA 0x3 +#define AD5360_CMD_WRITE_OFFSET 0x2 +#define AD5360_CMD_WRITE_GAIN 0x1 +#define AD5360_CMD_SPECIAL_FUNCTION 0x0 + +/* Special function register addresses */ +#define AD5360_REG_SF_NOP 0x0 +#define AD5360_REG_SF_CTRL 0x1 +#define AD5360_REG_SF_OFS(x) (0x2 + (x)) +#define AD5360_REG_SF_READBACK 0x5 + +#define AD5360_SF_CTRL_PWR_DOWN BIT(0) + +#define AD5360_READBACK_X1A 0x0 +#define AD5360_READBACK_X1B 0x1 +#define AD5360_READBACK_OFFSET 0x2 +#define AD5360_READBACK_GAIN 0x3 +#define AD5360_READBACK_SF 0x4 + + +/** + * struct ad5360_chip_info - chip specific information + * @channel_template: channel specification template + * @num_channels: number of channels + * @channels_per_group: number of channels per group + * @num_vrefs: number of vref supplies for the chip +*/ + +struct ad5360_chip_info { + struct iio_chan_spec channel_template; + unsigned int num_channels; + unsigned int channels_per_group; + unsigned int num_vrefs; +}; + +/** + * struct ad5360_state - driver instance specific data + * @spi: spi_device + * @chip_info: chip model specific constants, available modes etc + * @vref_reg: vref supply regulators + * @ctrl: control register cache + * @data: spi transfer buffers + */ + +struct ad5360_state { + struct spi_device *spi; + const struct ad5360_chip_info *chip_info; + struct regulator_bulk_data vref_reg[3]; + unsigned int ctrl; + + /* + * DMA (thus cache coherency maintenance) requires the + * transfer buffers to live in their own cache lines. + */ + union { + __be32 d32; + u8 d8[4]; + } data[2] ____cacheline_aligned; +}; + +enum ad5360_type { + ID_AD5360, + ID_AD5361, + ID_AD5362, + ID_AD5363, + ID_AD5370, + ID_AD5371, + ID_AD5372, + ID_AD5373, +}; + +#define AD5360_CHANNEL(bits) { \ + .type = IIO_VOLTAGE, \ + .indexed = 1, \ + .output = 1, \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ + BIT(IIO_CHAN_INFO_SCALE) | \ + BIT(IIO_CHAN_INFO_OFFSET) | \ + BIT(IIO_CHAN_INFO_CALIBSCALE) | \ + BIT(IIO_CHAN_INFO_CALIBBIAS), \ + .scan_type = { \ + .sign = 'u', \ + .realbits = (bits), \ + .storagebits = 16, \ + .shift = 16 - (bits), \ + }, \ +} + +static const struct ad5360_chip_info ad5360_chip_info_tbl[] = { + [ID_AD5360] = { + .channel_template = AD5360_CHANNEL(16), + .num_channels = 16, + .channels_per_group = 8, + .num_vrefs = 2, + }, + [ID_AD5361] = { + .channel_template = AD5360_CHANNEL(14), + .num_channels = 16, + .channels_per_group = 8, + .num_vrefs = 2, + }, + [ID_AD5362] = { + .channel_template = AD5360_CHANNEL(16), + .num_channels = 8, + .channels_per_group = 4, + .num_vrefs = 2, + }, + [ID_AD5363] = { + .channel_template = AD5360_CHANNEL(14), + .num_channels = 8, + .channels_per_group = 4, + .num_vrefs = 2, + }, + [ID_AD5370] = { + .channel_template = AD5360_CHANNEL(16), + .num_channels = 40, + .channels_per_group = 8, + .num_vrefs = 2, + }, + [ID_AD5371] = { + .channel_template = AD5360_CHANNEL(14), + .num_channels = 40, + .channels_per_group = 8, + .num_vrefs = 3, + }, + [ID_AD5372] = { + .channel_template = AD5360_CHANNEL(16), + .num_channels = 32, + .channels_per_group = 8, + .num_vrefs = 2, + }, + [ID_AD5373] = { + .channel_template = AD5360_CHANNEL(14), + .num_channels = 32, + .channels_per_group = 8, + .num_vrefs = 2, + }, +}; + +static unsigned int ad5360_get_channel_vref_index(struct ad5360_state *st, + unsigned int channel) +{ + unsigned int i; + + /* The first groups have their own vref, while the remaining groups + * share the last vref */ + i = channel / st->chip_info->channels_per_group; + if (i >= st->chip_info->num_vrefs) + i = st->chip_info->num_vrefs - 1; + + return i; +} + +static int ad5360_get_channel_vref(struct ad5360_state *st, + unsigned int channel) +{ + unsigned int i = ad5360_get_channel_vref_index(st, channel); + + return regulator_get_voltage(st->vref_reg[i].consumer); +} + + +static int ad5360_write_unlocked(struct iio_dev *indio_dev, + unsigned int cmd, unsigned int addr, unsigned int val, + unsigned int shift) +{ + struct ad5360_state *st = iio_priv(indio_dev); + + val <<= shift; + val |= AD5360_CMD(cmd) | AD5360_ADDR(addr); + st->data[0].d32 = cpu_to_be32(val); + + return spi_write(st->spi, &st->data[0].d8[1], 3); +} + +static int ad5360_write(struct iio_dev *indio_dev, unsigned int cmd, + unsigned int addr, unsigned int val, unsigned int shift) +{ + int ret; + + mutex_lock(&indio_dev->mlock); + ret = ad5360_write_unlocked(indio_dev, cmd, addr, val, shift); + mutex_unlock(&indio_dev->mlock); + + return ret; +} + +static int ad5360_read(struct iio_dev *indio_dev, unsigned int type, + unsigned int addr) +{ + struct ad5360_state *st = iio_priv(indio_dev); + 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, + }, + }; + + mutex_lock(&indio_dev->mlock); + + st->data[0].d32 = cpu_to_be32(AD5360_CMD(AD5360_CMD_SPECIAL_FUNCTION) | + AD5360_ADDR(AD5360_REG_SF_READBACK) | + AD5360_READBACK_TYPE(type) | + AD5360_READBACK_ADDR(addr)); + + ret = spi_sync_transfer(st->spi, t, ARRAY_SIZE(t)); + if (ret >= 0) + ret = be32_to_cpu(st->data[1].d32) & 0xffff; + + mutex_unlock(&indio_dev->mlock); + + return ret; +} + +static ssize_t ad5360_read_dac_powerdown(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct iio_dev *indio_dev = dev_to_iio_dev(dev); + struct ad5360_state *st = iio_priv(indio_dev); + + return sprintf(buf, "%d\n", (bool)(st->ctrl & AD5360_SF_CTRL_PWR_DOWN)); +} + +static int ad5360_update_ctrl(struct iio_dev *indio_dev, unsigned int set, + unsigned int clr) +{ + struct ad5360_state *st = iio_priv(indio_dev); + unsigned int ret; + + mutex_lock(&indio_dev->mlock); + + st->ctrl |= set; + st->ctrl &= ~clr; + + ret = ad5360_write_unlocked(indio_dev, AD5360_CMD_SPECIAL_FUNCTION, + AD5360_REG_SF_CTRL, st->ctrl, 0); + + mutex_unlock(&indio_dev->mlock); + + return ret; +} + +static ssize_t ad5360_write_dac_powerdown(struct device *dev, + struct device_attribute *attr, const char *buf, size_t len) +{ + struct iio_dev *indio_dev = dev_to_iio_dev(dev); + bool pwr_down; + int ret; + + ret = strtobool(buf, &pwr_down); + if (ret) + return ret; + + if (pwr_down) + ret = ad5360_update_ctrl(indio_dev, AD5360_SF_CTRL_PWR_DOWN, 0); + else + ret = ad5360_update_ctrl(indio_dev, 0, AD5360_SF_CTRL_PWR_DOWN); + + return ret ? ret : len; +} + +static IIO_DEVICE_ATTR(out_voltage_powerdown, + S_IRUGO | S_IWUSR, + ad5360_read_dac_powerdown, + ad5360_write_dac_powerdown, 0); + +static struct attribute *ad5360_attributes[] = { + &iio_dev_attr_out_voltage_powerdown.dev_attr.attr, + NULL, +}; + +static const struct attribute_group ad5360_attribute_group = { + .attrs = ad5360_attributes, +}; + +static int ad5360_write_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int val, + int val2, + long mask) +{ + struct ad5360_state *st = iio_priv(indio_dev); + int max_val = (1 << chan->scan_type.realbits); + unsigned int ofs_index; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + if (val >= max_val || val < 0) + return -EINVAL; + + return ad5360_write(indio_dev, AD5360_CMD_WRITE_DATA, + chan->address, val, chan->scan_type.shift); + + case IIO_CHAN_INFO_CALIBBIAS: + if (val >= max_val || val < 0) + return -EINVAL; + + return ad5360_write(indio_dev, AD5360_CMD_WRITE_OFFSET, + chan->address, val, chan->scan_type.shift); + + case IIO_CHAN_INFO_CALIBSCALE: + if (val >= max_val || val < 0) + return -EINVAL; + + return ad5360_write(indio_dev, AD5360_CMD_WRITE_GAIN, + chan->address, val, chan->scan_type.shift); + + case IIO_CHAN_INFO_OFFSET: + if (val <= -max_val || val > 0) + return -EINVAL; + + val = -val; + + /* offset is supposed to have the same scale as raw, but it + * is always 14bits wide, so on a chip where the raw value has + * more bits, we need to shift offset. */ + val >>= (chan->scan_type.realbits - 14); + + /* There is one DAC offset register per vref. Changing one + * channels offset will also change the offset for all other + * channels which share the same vref supply. */ + ofs_index = ad5360_get_channel_vref_index(st, chan->channel); + return ad5360_write(indio_dev, AD5360_CMD_SPECIAL_FUNCTION, + AD5360_REG_SF_OFS(ofs_index), val, 0); + default: + break; + } + + return -EINVAL; +} + +static int ad5360_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, + int *val2, + long m) +{ + struct ad5360_state *st = iio_priv(indio_dev); + unsigned int ofs_index; + int scale_uv; + int ret; + + switch (m) { + case IIO_CHAN_INFO_RAW: + ret = ad5360_read(indio_dev, AD5360_READBACK_X1A, + chan->address); + if (ret < 0) + return ret; + *val = ret >> chan->scan_type.shift; + return IIO_VAL_INT; + case IIO_CHAN_INFO_SCALE: + scale_uv = ad5360_get_channel_vref(st, chan->channel); + if (scale_uv < 0) + return scale_uv; + + /* vout = 4 * vref * dac_code */ + *val = scale_uv * 4 / 1000; + *val2 = chan->scan_type.realbits; + return IIO_VAL_FRACTIONAL_LOG2; + case IIO_CHAN_INFO_CALIBBIAS: + ret = ad5360_read(indio_dev, AD5360_READBACK_OFFSET, + chan->address); + if (ret < 0) + return ret; + *val = ret; + return IIO_VAL_INT; + case IIO_CHAN_INFO_CALIBSCALE: + ret = ad5360_read(indio_dev, AD5360_READBACK_GAIN, + chan->address); + if (ret < 0) + return ret; + *val = ret; + return IIO_VAL_INT; + case IIO_CHAN_INFO_OFFSET: + ofs_index = ad5360_get_channel_vref_index(st, chan->channel); + ret = ad5360_read(indio_dev, AD5360_READBACK_SF, + AD5360_REG_SF_OFS(ofs_index)); + if (ret < 0) + return ret; + + ret <<= (chan->scan_type.realbits - 14); + *val = -ret; + return IIO_VAL_INT; + } + + return -EINVAL; +} + +static const struct iio_info ad5360_info = { + .read_raw = ad5360_read_raw, + .write_raw = ad5360_write_raw, + .attrs = &ad5360_attribute_group, +}; + +static const char * const ad5360_vref_name[] = { + "vref0", "vref1", "vref2" +}; + +static int ad5360_alloc_channels(struct iio_dev *indio_dev) +{ + struct ad5360_state *st = iio_priv(indio_dev); + struct iio_chan_spec *channels; + unsigned int i; + + channels = kcalloc(st->chip_info->num_channels, + sizeof(struct iio_chan_spec), GFP_KERNEL); + + if (!channels) + return -ENOMEM; + + for (i = 0; i < st->chip_info->num_channels; ++i) { + channels[i] = st->chip_info->channel_template; + channels[i].channel = i; + channels[i].address = AD5360_CHAN_ADDR(i); + } + + indio_dev->channels = channels; + + return 0; +} + +static int ad5360_probe(struct spi_device *spi) +{ + enum ad5360_type type = spi_get_device_id(spi)->driver_data; + struct iio_dev *indio_dev; + struct ad5360_state *st; + unsigned int i; + int ret; + + indio_dev = devm_iio_device_alloc(&spi->dev, 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->chip_info = &ad5360_chip_info_tbl[type]; + st->spi = spi; + + indio_dev->dev.parent = &spi->dev; + indio_dev->name = spi_get_device_id(spi)->name; + indio_dev->info = &ad5360_info; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->num_channels = st->chip_info->num_channels; + + ret = ad5360_alloc_channels(indio_dev); + if (ret) { + dev_err(&spi->dev, "Failed to allocate channel spec: %d\n", ret); + return ret; + } + + for (i = 0; i < st->chip_info->num_vrefs; ++i) + st->vref_reg[i].supply = ad5360_vref_name[i]; + + ret = devm_regulator_bulk_get(&st->spi->dev, st->chip_info->num_vrefs, + st->vref_reg); + if (ret) { + dev_err(&spi->dev, "Failed to request vref regulators: %d\n", ret); + goto error_free_channels; + } + + ret = regulator_bulk_enable(st->chip_info->num_vrefs, st->vref_reg); + if (ret) { + dev_err(&spi->dev, "Failed to enable vref regulators: %d\n", ret); + goto error_free_channels; + } + + ret = iio_device_register(indio_dev); + if (ret) { + dev_err(&spi->dev, "Failed to register iio device: %d\n", ret); + goto error_disable_reg; + } + + return 0; + +error_disable_reg: + regulator_bulk_disable(st->chip_info->num_vrefs, st->vref_reg); +error_free_channels: + kfree(indio_dev->channels); + + return ret; +} + +static int ad5360_remove(struct spi_device *spi) +{ + struct iio_dev *indio_dev = spi_get_drvdata(spi); + struct ad5360_state *st = iio_priv(indio_dev); + + iio_device_unregister(indio_dev); + + kfree(indio_dev->channels); + + regulator_bulk_disable(st->chip_info->num_vrefs, st->vref_reg); + + return 0; +} + +static const struct spi_device_id ad5360_ids[] = { + { "ad5360", ID_AD5360 }, + { "ad5361", ID_AD5361 }, + { "ad5362", ID_AD5362 }, + { "ad5363", ID_AD5363 }, + { "ad5370", ID_AD5370 }, + { "ad5371", ID_AD5371 }, + { "ad5372", ID_AD5372 }, + { "ad5373", ID_AD5373 }, + {} +}; +MODULE_DEVICE_TABLE(spi, ad5360_ids); + +static struct spi_driver ad5360_driver = { + .driver = { + .name = "ad5360", + }, + .probe = ad5360_probe, + .remove = ad5360_remove, + .id_table = ad5360_ids, +}; +module_spi_driver(ad5360_driver); + +MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>"); +MODULE_DESCRIPTION("Analog Devices AD5360/61/62/63/70/71/72/73 DAC"); +MODULE_LICENSE("GPL v2"); |