--- /dev/null
+/*
+ * AD5755, AD5755-1, AD5757, AD5735, AD5737 Digital to analog converters driver
+ *
+ * Copyright 2012 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/delay.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/platform_data/ad5755.h>
+
+#define AD5755_NUM_CHANNELS 4
+
+#define AD5755_ADDR(x) ((x) << 16)
+
+#define AD5755_WRITE_REG_DATA(chan) (chan)
+#define AD5755_WRITE_REG_GAIN(chan) (0x08 | (chan))
+#define AD5755_WRITE_REG_OFFSET(chan) (0x10 | (chan))
+#define AD5755_WRITE_REG_CTRL(chan) (0x1c | (chan))
+
+#define AD5755_READ_REG_DATA(chan) (chan)
+#define AD5755_READ_REG_CTRL(chan) (0x4 | (chan))
+#define AD5755_READ_REG_GAIN(chan) (0x8 | (chan))
+#define AD5755_READ_REG_OFFSET(chan) (0xc | (chan))
+#define AD5755_READ_REG_CLEAR(chan) (0x10 | (chan))
+#define AD5755_READ_REG_SLEW(chan) (0x14 | (chan))
+#define AD5755_READ_REG_STATUS 0x18
+#define AD5755_READ_REG_MAIN 0x19
+#define AD5755_READ_REG_DC_DC 0x1a
+
+#define AD5755_CTRL_REG_SLEW 0x0
+#define AD5755_CTRL_REG_MAIN 0x1
+#define AD5755_CTRL_REG_DAC 0x2
+#define AD5755_CTRL_REG_DC_DC 0x3
+#define AD5755_CTRL_REG_SW 0x4
+
+#define AD5755_READ_FLAG 0x800000
+
+#define AD5755_NOOP 0x1CE000
+
+#define AD5755_DAC_INT_EN BIT(8)
+#define AD5755_DAC_CLR_EN BIT(7)
+#define AD5755_DAC_OUT_EN BIT(6)
+#define AD5755_DAC_INT_CURRENT_SENSE_RESISTOR BIT(5)
+#define AD5755_DAC_DC_DC_EN BIT(4)
+#define AD5755_DAC_VOLTAGE_OVERRANGE_EN BIT(3)
+
+#define AD5755_DC_DC_MAXV 0
+#define AD5755_DC_DC_FREQ_SHIFT 2
+#define AD5755_DC_DC_PHASE_SHIFT 4
+#define AD5755_EXT_DC_DC_COMP_RES BIT(6)
+
+#define AD5755_SLEW_STEP_SIZE_SHIFT 0
+#define AD5755_SLEW_RATE_SHIFT 3
+#define AD5755_SLEW_ENABLE BIT(12)
+
+/**
+ * struct ad5755_chip_info - chip specific information
+ * @channel_template: channel specification
+ * @calib_shift: shift for the calibration data registers
+ * @has_voltage_out: whether the chip has voltage outputs
+ */
+struct ad5755_chip_info {
+ const struct iio_chan_spec channel_template;
+ unsigned int calib_shift;
+ bool has_voltage_out;
+};
+
+/**
+ * struct ad5755_state - driver instance specific data
+ * @spi: spi device the driver is attached to
+ * @chip_info: chip model specific constants, available modes etc
+ * @pwr_down: bitmask which contains hether a channel is powered down or not
+ * @ctrl: software shadow of the channel ctrl registers
+ * @channels: iio channel spec for the device
+ * @data: spi transfer buffers
+ */
+struct ad5755_state {
+ struct spi_device *spi;
+ const struct ad5755_chip_info *chip_info;
+ unsigned int pwr_down;
+ unsigned int ctrl[AD5755_NUM_CHANNELS];
+ struct iio_chan_spec channels[AD5755_NUM_CHANNELS];
+
+ /*
+ * 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 ad5755_type {
+ ID_AD5755,
+ ID_AD5757,
+ ID_AD5735,
+ ID_AD5737,
+};
+
+static int ad5755_write_unlocked(struct iio_dev *indio_dev,
+ unsigned int reg, unsigned int val)
+{
+ struct ad5755_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 ad5755_write_ctrl_unlocked(struct iio_dev *indio_dev,
+ unsigned int channel, unsigned int reg, unsigned int val)
+{
+ return ad5755_write_unlocked(indio_dev,
+ AD5755_WRITE_REG_CTRL(channel), (reg << 13) | val);
+}
+
+static int ad5755_write(struct iio_dev *indio_dev, unsigned int reg,
+ unsigned int val)
+{
+ int ret;
+
+ mutex_lock(&indio_dev->mlock);
+ ret = ad5755_write_unlocked(indio_dev, reg, val);
+ mutex_unlock(&indio_dev->mlock);
+
+ return ret;
+}
+
+static int ad5755_write_ctrl(struct iio_dev *indio_dev, unsigned int channel,
+ unsigned int reg, unsigned int val)
+{
+ int ret;
+
+ mutex_lock(&indio_dev->mlock);
+ ret = ad5755_write_ctrl_unlocked(indio_dev, channel, reg, val);
+ mutex_unlock(&indio_dev->mlock);
+
+ return ret;
+}
+
+static int ad5755_read(struct iio_dev *indio_dev, unsigned int addr)
+{
+ struct ad5755_state *st = iio_priv(indio_dev);
+ int ret;
+ struct spi_transfer t[] = {
+ {
+ .tx_buf = &st->data[0].d8[1],
+ .len = 3,
+ .cs_change = 1,
+ }, {
+ .tx_buf = &st->data[1].d8[1],
+ .rx_buf = &st->data[1].d8[1],
+ .len = 3,
+ },
+ };
+
+ mutex_lock(&indio_dev->mlock);
+
+ st->data[0].d32 = cpu_to_be32(AD5755_READ_FLAG | (addr << 16));
+ st->data[1].d32 = cpu_to_be32(AD5755_NOOP);
+
+ 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 int ad5755_update_dac_ctrl(struct iio_dev *indio_dev,
+ unsigned int channel, unsigned int set, unsigned int clr)
+{
+ struct ad5755_state *st = iio_priv(indio_dev);
+ int ret;
+
+ st->ctrl[channel] |= set;
+ st->ctrl[channel] &= ~clr;
+
+ ret = ad5755_write_ctrl_unlocked(indio_dev, channel,
+ AD5755_CTRL_REG_DAC, st->ctrl[channel]);
+
+ return ret;
+}
+
+static int ad5755_set_channel_pwr_down(struct iio_dev *indio_dev,
+ unsigned int channel, bool pwr_down)
+{
+ struct ad5755_state *st = iio_priv(indio_dev);
+ unsigned int mask = BIT(channel);
+
+ mutex_lock(&indio_dev->mlock);
+
+ if ((bool)(st->pwr_down & mask) == pwr_down)
+ goto out_unlock;
+
+ if (!pwr_down) {
+ st->pwr_down &= ~mask;
+ ad5755_update_dac_ctrl(indio_dev, channel,
+ AD5755_DAC_INT_EN | AD5755_DAC_DC_DC_EN, 0);
+ udelay(200);
+ ad5755_update_dac_ctrl(indio_dev, channel,
+ AD5755_DAC_OUT_EN, 0);
+ } else {
+ st->pwr_down |= mask;
+ ad5755_update_dac_ctrl(indio_dev, channel,
+ 0, AD5755_DAC_INT_EN | AD5755_DAC_OUT_EN |
+ AD5755_DAC_DC_DC_EN);
+ }
+
+out_unlock:
+ mutex_unlock(&indio_dev->mlock);
+
+ return 0;
+}
+
+static const int ad5755_min_max_table[][2] = {
+ [AD5755_MODE_VOLTAGE_0V_5V] = { 0, 5000 },
+ [AD5755_MODE_VOLTAGE_0V_10V] = { 0, 10000 },
+ [AD5755_MODE_VOLTAGE_PLUSMINUS_5V] = { -5000, 5000 },
+ [AD5755_MODE_VOLTAGE_PLUSMINUS_10V] = { -10000, 10000 },
+ [AD5755_MODE_CURRENT_4mA_20mA] = { 4, 20 },
+ [AD5755_MODE_CURRENT_0mA_20mA] = { 0, 20 },
+ [AD5755_MODE_CURRENT_0mA_24mA] = { 0, 24 },
+};
+
+static void ad5755_get_min_max(struct ad5755_state *st,
+ struct iio_chan_spec const *chan, int *min, int *max)
+{
+ enum ad5755_mode mode = st->ctrl[chan->channel] & 7;
+ *min = ad5755_min_max_table[mode][0];
+ *max = ad5755_min_max_table[mode][1];
+}
+
+static inline int ad5755_get_offset(struct ad5755_state *st,
+ struct iio_chan_spec const *chan)
+{
+ int min, max;
+
+ ad5755_get_min_max(st, chan, &min, &max);
+ return (min * (1 << chan->scan_type.realbits)) / (max - min);
+}
+
+static int ad5755_chan_reg_info(struct ad5755_state *st,
+ struct iio_chan_spec const *chan, long info, bool write,
+ unsigned int *reg, unsigned int *shift, unsigned int *offset)
+{
+ switch (info) {
+ case IIO_CHAN_INFO_RAW:
+ if (write)
+ *reg = AD5755_WRITE_REG_DATA(chan->address);
+ else
+ *reg = AD5755_READ_REG_DATA(chan->address);
+ *shift = chan->scan_type.shift;
+ *offset = 0;
+ break;
+ case IIO_CHAN_INFO_CALIBBIAS:
+ if (write)
+ *reg = AD5755_WRITE_REG_OFFSET(chan->address);
+ else
+ *reg = AD5755_READ_REG_OFFSET(chan->address);
+ *shift = st->chip_info->calib_shift;
+ *offset = 32768;
+ break;
+ case IIO_CHAN_INFO_CALIBSCALE:
+ if (write)
+ *reg = AD5755_WRITE_REG_GAIN(chan->address);
+ else
+ *reg = AD5755_READ_REG_GAIN(chan->address);
+ *shift = st->chip_info->calib_shift;
+ *offset = 0;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int ad5755_read_raw(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan, int *val, int *val2, long info)
+{
+ struct ad5755_state *st = iio_priv(indio_dev);
+ unsigned int reg, shift, offset;
+ int min, max;
+ int ret;
+
+ switch (info) {
+ case IIO_CHAN_INFO_SCALE:
+ ad5755_get_min_max(st, chan, &min, &max);
+ *val = max - min;
+ *val2 = chan->scan_type.realbits;
+ return IIO_VAL_FRACTIONAL_LOG2;
+ case IIO_CHAN_INFO_OFFSET:
+ *val = ad5755_get_offset(st, chan);
+ return IIO_VAL_INT;
+ default:
+ ret = ad5755_chan_reg_info(st, chan, info, false,
+ ®, &shift, &offset);
+ if (ret)
+ return ret;
+
+ ret = ad5755_read(indio_dev, reg);
+ if (ret < 0)
+ return ret;
+
+ *val = (ret - offset) >> shift;
+
+ return IIO_VAL_INT;
+ }
+
+ return -EINVAL;
+}
+
+static int ad5755_write_raw(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan, int val, int val2, long info)
+{
+ struct ad5755_state *st = iio_priv(indio_dev);
+ unsigned int shift, reg, offset;
+ int ret;
+
+ ret = ad5755_chan_reg_info(st, chan, info, true,
+ ®, &shift, &offset);
+ if (ret)
+ return ret;
+
+ val <<= shift;
+ val += offset;
+
+ if (val < 0 || val > 0xffff)
+ return -EINVAL;
+
+ return ad5755_write(indio_dev, reg, val);
+}
+
+static ssize_t ad5755_read_powerdown(struct iio_dev *indio_dev, uintptr_t priv,
+ const struct iio_chan_spec *chan, char *buf)
+{
+ struct ad5755_state *st = iio_priv(indio_dev);
+
+ return sprintf(buf, "%d\n",
+ (bool)(st->pwr_down & (1 << chan->channel)));
+}
+
+static ssize_t ad5755_write_powerdown(struct iio_dev *indio_dev, uintptr_t priv,
+ struct iio_chan_spec const *chan, const char *buf, size_t len)
+{
+ bool pwr_down;
+ int ret;
+
+ ret = strtobool(buf, &pwr_down);
+ if (ret)
+ return ret;
+
+ ret = ad5755_set_channel_pwr_down(indio_dev, chan->channel, pwr_down);
+ return ret ? ret : len;
+}
+
+static const struct iio_info ad5755_info = {
+ .read_raw = ad5755_read_raw,
+ .write_raw = ad5755_write_raw,
+ .driver_module = THIS_MODULE,
+};
+
+static const struct iio_chan_spec_ext_info ad5755_ext_info[] = {
+ {
+ .name = "powerdown",
+ .read = ad5755_read_powerdown,
+ .write = ad5755_write_powerdown,
+ .shared = IIO_SEPARATE,
+ },
+ { },
+};
+
+#define AD5755_CHANNEL(_bits) { \
+ .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), \
+ }, \
+ .ext_info = ad5755_ext_info, \
+}
+
+static const struct ad5755_chip_info ad5755_chip_info_tbl[] = {
+ [ID_AD5735] = {
+ .channel_template = AD5755_CHANNEL(14),
+ .has_voltage_out = true,
+ .calib_shift = 4,
+ },
+ [ID_AD5737] = {
+ .channel_template = AD5755_CHANNEL(14),
+ .has_voltage_out = false,
+ .calib_shift = 4,
+ },
+ [ID_AD5755] = {
+ .channel_template = AD5755_CHANNEL(16),
+ .has_voltage_out = true,
+ .calib_shift = 0,
+ },
+ [ID_AD5757] = {
+ .channel_template = AD5755_CHANNEL(16),
+ .has_voltage_out = false,
+ .calib_shift = 0,
+ },
+};
+
+static bool ad5755_is_valid_mode(struct ad5755_state *st, enum ad5755_mode mode)
+{
+ switch (mode) {
+ case AD5755_MODE_VOLTAGE_0V_5V:
+ case AD5755_MODE_VOLTAGE_0V_10V:
+ case AD5755_MODE_VOLTAGE_PLUSMINUS_5V:
+ case AD5755_MODE_VOLTAGE_PLUSMINUS_10V:
+ return st->chip_info->has_voltage_out;
+ case AD5755_MODE_CURRENT_4mA_20mA:
+ case AD5755_MODE_CURRENT_0mA_20mA:
+ case AD5755_MODE_CURRENT_0mA_24mA:
+ return true;
+ default:
+ return false;
+ }
+}
+
+static int ad5755_setup_pdata(struct iio_dev *indio_dev,
+ const struct ad5755_platform_data *pdata)
+{
+ struct ad5755_state *st = iio_priv(indio_dev);
+ unsigned int val;
+ unsigned int i;
+ int ret;
+
+ if (pdata->dc_dc_phase > AD5755_DC_DC_PHASE_90_DEGREE ||
+ pdata->dc_dc_freq > AD5755_DC_DC_FREQ_650kHZ ||
+ pdata->dc_dc_maxv > AD5755_DC_DC_MAXV_29V5)
+ return -EINVAL;
+
+ val = pdata->dc_dc_maxv << AD5755_DC_DC_MAXV;
+ val |= pdata->dc_dc_freq << AD5755_DC_DC_FREQ_SHIFT;
+ val |= pdata->dc_dc_phase << AD5755_DC_DC_PHASE_SHIFT;
+ if (pdata->ext_dc_dc_compenstation_resistor)
+ val |= AD5755_EXT_DC_DC_COMP_RES;
+
+ ret = ad5755_write_ctrl(indio_dev, 0, AD5755_CTRL_REG_DC_DC, val);
+ if (ret < 0)
+ return ret;
+
+ for (i = 0; i < ARRAY_SIZE(pdata->dac); ++i) {
+ val = pdata->dac[i].slew.step_size <<
+ AD5755_SLEW_STEP_SIZE_SHIFT;
+ val |= pdata->dac[i].slew.rate <<
+ AD5755_SLEW_RATE_SHIFT;
+ if (pdata->dac[i].slew.enable)
+ val |= AD5755_SLEW_ENABLE;
+
+ ret = ad5755_write_ctrl(indio_dev, i,
+ AD5755_CTRL_REG_SLEW, val);
+ if (ret < 0)
+ return ret;
+ }
+
+ for (i = 0; i < ARRAY_SIZE(pdata->dac); ++i) {
+ if (!ad5755_is_valid_mode(st, pdata->dac[i].mode))
+ return -EINVAL;
+
+ val = 0;
+ if (!pdata->dac[i].ext_current_sense_resistor)
+ val |= AD5755_DAC_INT_CURRENT_SENSE_RESISTOR;
+ if (pdata->dac[i].enable_voltage_overrange)
+ val |= AD5755_DAC_VOLTAGE_OVERRANGE_EN;
+ val |= pdata->dac[i].mode;
+
+ ret = ad5755_update_dac_ctrl(indio_dev, i, val, 0);
+ if (ret < 0)
+ return ret;
+ }
+
+ return 0;
+}
+
+static bool ad5755_is_voltage_mode(enum ad5755_mode mode)
+{
+ switch (mode) {
+ case AD5755_MODE_VOLTAGE_0V_5V:
+ case AD5755_MODE_VOLTAGE_0V_10V:
+ case AD5755_MODE_VOLTAGE_PLUSMINUS_5V:
+ case AD5755_MODE_VOLTAGE_PLUSMINUS_10V:
+ return true;
+ default:
+ return false;
+ }
+}
+
+static int ad5755_init_channels(struct iio_dev *indio_dev,
+ const struct ad5755_platform_data *pdata)
+{
+ struct ad5755_state *st = iio_priv(indio_dev);
+ struct iio_chan_spec *channels = st->channels;
+ unsigned int i;
+
+ for (i = 0; i < AD5755_NUM_CHANNELS; ++i) {
+ channels[i] = st->chip_info->channel_template;
+ channels[i].channel = i;
+ channels[i].address = i;
+ if (pdata && ad5755_is_voltage_mode(pdata->dac[i].mode))
+ channels[i].type = IIO_VOLTAGE;
+ else
+ channels[i].type = IIO_CURRENT;
+ }
+
+ indio_dev->channels = channels;
+
+ return 0;
+}
+
+#define AD5755_DEFAULT_DAC_PDATA { \
+ .mode = AD5755_MODE_CURRENT_4mA_20mA, \
+ .ext_current_sense_resistor = true, \
+ .enable_voltage_overrange = false, \
+ .slew = { \
+ .enable = false, \
+ .rate = AD5755_SLEW_RATE_64k, \
+ .step_size = AD5755_SLEW_STEP_SIZE_1, \
+ }, \
+ }
+
+static const struct ad5755_platform_data ad5755_default_pdata = {
+ .ext_dc_dc_compenstation_resistor = false,
+ .dc_dc_phase = AD5755_DC_DC_PHASE_ALL_SAME_EDGE,
+ .dc_dc_freq = AD5755_DC_DC_FREQ_410kHZ,
+ .dc_dc_maxv = AD5755_DC_DC_MAXV_23V,
+ .dac = {
+ [0] = AD5755_DEFAULT_DAC_PDATA,
+ [1] = AD5755_DEFAULT_DAC_PDATA,
+ [2] = AD5755_DEFAULT_DAC_PDATA,
+ [3] = AD5755_DEFAULT_DAC_PDATA,
+ },
+};
+
+static int ad5755_probe(struct spi_device *spi)
+{
+ enum ad5755_type type = spi_get_device_id(spi)->driver_data;
+ const struct ad5755_platform_data *pdata = dev_get_platdata(&spi->dev);
+ struct iio_dev *indio_dev;
+ struct ad5755_state *st;
+ 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 = &ad5755_chip_info_tbl[type];
+ st->spi = spi;
+ st->pwr_down = 0xf;
+
+ indio_dev->dev.parent = &spi->dev;
+ indio_dev->name = spi_get_device_id(spi)->name;
+ indio_dev->info = &ad5755_info;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->num_channels = AD5755_NUM_CHANNELS;
+
+ if (!pdata)
+ pdata = &ad5755_default_pdata;
+
+ ret = ad5755_init_channels(indio_dev, pdata);
+ if (ret)
+ return ret;
+
+ ret = ad5755_setup_pdata(indio_dev, pdata);
+ if (ret)
+ return ret;
+
+ return devm_iio_device_register(&spi->dev, indio_dev);
+}
+
+static const struct spi_device_id ad5755_id[] = {
+ { "ad5755", ID_AD5755 },
+ { "ad5755-1", ID_AD5755 },
+ { "ad5757", ID_AD5757 },
+ { "ad5735", ID_AD5735 },
+ { "ad5737", ID_AD5737 },
+ {}
+};
+MODULE_DEVICE_TABLE(spi, ad5755_id);
+
+static struct spi_driver ad5755_driver = {
+ .driver = {
+ .name = "ad5755",
+ .owner = THIS_MODULE,
+ },
+ .probe = ad5755_probe,
+ .id_table = ad5755_id,
+};
+module_spi_driver(ad5755_driver);
+
+MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
+MODULE_DESCRIPTION("Analog Devices AD5755/55-1/57/35/37 DAC");
+MODULE_LICENSE("GPL v2");
Code Review / kvmfornfv.git / blobdiff