--- /dev/null
+/*
+ * AD5686R, AD5685R, AD5684R Digital to analog converters driver
+ *
+ * Copyright 2011 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/fs.h>
+#include <linux/device.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 AD5686_DAC_CHANNELS 4
+
+#define AD5686_ADDR(x) ((x) << 16)
+#define AD5686_CMD(x) ((x) << 20)
+
+#define AD5686_ADDR_DAC(chan) (0x1 << (chan))
+#define AD5686_ADDR_ALL_DAC 0xF
+
+#define AD5686_CMD_NOOP 0x0
+#define AD5686_CMD_WRITE_INPUT_N 0x1
+#define AD5686_CMD_UPDATE_DAC_N 0x2
+#define AD5686_CMD_WRITE_INPUT_N_UPDATE_N 0x3
+#define AD5686_CMD_POWERDOWN_DAC 0x4
+#define AD5686_CMD_LDAC_MASK 0x5
+#define AD5686_CMD_RESET 0x6
+#define AD5686_CMD_INTERNAL_REFER_SETUP 0x7
+#define AD5686_CMD_DAISY_CHAIN_ENABLE 0x8
+#define AD5686_CMD_READBACK_ENABLE 0x9
+
+#define AD5686_LDAC_PWRDN_NONE 0x0
+#define AD5686_LDAC_PWRDN_1K 0x1
+#define AD5686_LDAC_PWRDN_100K 0x2
+#define AD5686_LDAC_PWRDN_3STATE 0x3
+
+/**
+ * struct ad5686_chip_info - chip specific information
+ * @int_vref_mv: AD5620/40/60: the internal reference voltage
+ * @channel: channel specification
+*/
+
+struct ad5686_chip_info {
+ u16 int_vref_mv;
+ struct iio_chan_spec channel[AD5686_DAC_CHANNELS];
+};
+
+/**
+ * struct ad5446_state - driver instance specific data
+ * @spi: spi_device
+ * @chip_info: chip model specific constants, available modes etc
+ * @reg: supply regulator
+ * @vref_mv: actual reference voltage used
+ * @pwr_down_mask: power down mask
+ * @pwr_down_mode: current power down mode
+ * @data: spi transfer buffers
+ */
+
+struct ad5686_state {
+ struct spi_device *spi;
+ const struct ad5686_chip_info *chip_info;
+ struct regulator *reg;
+ unsigned short vref_mv;
+ unsigned pwr_down_mask;
+ unsigned pwr_down_mode;
+ /*
+ * DMA (thus cache coherency maintenance) requires the
+ * transfer buffers to live in their own cache lines.
+ */
+
+ union {
+ __be32 d32;
+ u8 d8[4];
+ } data[3] ____cacheline_aligned;
+};
+
+/**
+ * ad5686_supported_device_ids:
+ */
+
+enum ad5686_supported_device_ids {
+ ID_AD5684,
+ ID_AD5685,
+ ID_AD5686,
+};
+static int ad5686_spi_write(struct ad5686_state *st,
+ u8 cmd, u8 addr, u16 val, u8 shift)
+{
+ val <<= shift;
+
+ st->data[0].d32 = cpu_to_be32(AD5686_CMD(cmd) |
+ AD5686_ADDR(addr) |
+ val);
+
+ return spi_write(st->spi, &st->data[0].d8[1], 3);
+}
+
+static int ad5686_spi_read(struct ad5686_state *st, u8 addr)
+{
+ 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[2].d8[1],
+ .len = 3,
+ },
+ };
+ int ret;
+
+ st->data[0].d32 = cpu_to_be32(AD5686_CMD(AD5686_CMD_READBACK_ENABLE) |
+ AD5686_ADDR(addr));
+ st->data[1].d32 = cpu_to_be32(AD5686_CMD(AD5686_CMD_NOOP));
+
+ ret = spi_sync_transfer(st->spi, t, ARRAY_SIZE(t));
+ if (ret < 0)
+ return ret;
+
+ return be32_to_cpu(st->data[2].d32);
+}
+
+static const char * const ad5686_powerdown_modes[] = {
+ "1kohm_to_gnd",
+ "100kohm_to_gnd",
+ "three_state"
+};
+
+static int ad5686_get_powerdown_mode(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan)
+{
+ struct ad5686_state *st = iio_priv(indio_dev);
+
+ return ((st->pwr_down_mode >> (chan->channel * 2)) & 0x3) - 1;
+}
+
+static int ad5686_set_powerdown_mode(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan, unsigned int mode)
+{
+ struct ad5686_state *st = iio_priv(indio_dev);
+
+ st->pwr_down_mode &= ~(0x3 << (chan->channel * 2));
+ st->pwr_down_mode |= ((mode + 1) << (chan->channel * 2));
+
+ return 0;
+}
+
+static const struct iio_enum ad5686_powerdown_mode_enum = {
+ .items = ad5686_powerdown_modes,
+ .num_items = ARRAY_SIZE(ad5686_powerdown_modes),
+ .get = ad5686_get_powerdown_mode,
+ .set = ad5686_set_powerdown_mode,
+};
+
+static ssize_t ad5686_read_dac_powerdown(struct iio_dev *indio_dev,
+ uintptr_t private, const struct iio_chan_spec *chan, char *buf)
+{
+ struct ad5686_state *st = iio_priv(indio_dev);
+
+ return sprintf(buf, "%d\n", !!(st->pwr_down_mask &
+ (0x3 << (chan->channel * 2))));
+}
+
+static ssize_t ad5686_write_dac_powerdown(struct iio_dev *indio_dev,
+ uintptr_t private, const struct iio_chan_spec *chan, const char *buf,
+ size_t len)
+{
+ bool readin;
+ int ret;
+ struct ad5686_state *st = iio_priv(indio_dev);
+
+ ret = strtobool(buf, &readin);
+ if (ret)
+ return ret;
+
+ if (readin)
+ st->pwr_down_mask |= (0x3 << (chan->channel * 2));
+ else
+ st->pwr_down_mask &= ~(0x3 << (chan->channel * 2));
+
+ ret = ad5686_spi_write(st, AD5686_CMD_POWERDOWN_DAC, 0,
+ st->pwr_down_mask & st->pwr_down_mode, 0);
+
+ return ret ? ret : len;
+}
+
+static int ad5686_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val,
+ int *val2,
+ long m)
+{
+ struct ad5686_state *st = iio_priv(indio_dev);
+ int ret;
+
+ switch (m) {
+ case IIO_CHAN_INFO_RAW:
+ mutex_lock(&indio_dev->mlock);
+ ret = ad5686_spi_read(st, chan->address);
+ mutex_unlock(&indio_dev->mlock);
+ if (ret < 0)
+ return ret;
+ *val = ret;
+ return IIO_VAL_INT;
+ case IIO_CHAN_INFO_SCALE:
+ *val = st->vref_mv;
+ *val2 = chan->scan_type.realbits;
+ return IIO_VAL_FRACTIONAL_LOG2;
+ }
+ return -EINVAL;
+}
+
+static int ad5686_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int val,
+ int val2,
+ long mask)
+{
+ struct ad5686_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;
+
+ mutex_lock(&indio_dev->mlock);
+ ret = ad5686_spi_write(st,
+ AD5686_CMD_WRITE_INPUT_N_UPDATE_N,
+ chan->address,
+ val,
+ chan->scan_type.shift);
+ mutex_unlock(&indio_dev->mlock);
+ break;
+ default:
+ ret = -EINVAL;
+ }
+
+ return ret;
+}
+
+static const struct iio_info ad5686_info = {
+ .read_raw = ad5686_read_raw,
+ .write_raw = ad5686_write_raw,
+ .driver_module = THIS_MODULE,
+};
+
+static const struct iio_chan_spec_ext_info ad5686_ext_info[] = {
+ {
+ .name = "powerdown",
+ .read = ad5686_read_dac_powerdown,
+ .write = ad5686_write_dac_powerdown,
+ .shared = IIO_SEPARATE,
+ },
+ IIO_ENUM("powerdown_mode", IIO_SEPARATE, &ad5686_powerdown_mode_enum),
+ IIO_ENUM_AVAILABLE("powerdown_mode", &ad5686_powerdown_mode_enum),
+ { },
+};
+
+#define AD5868_CHANNEL(chan, bits, _shift) { \
+ .type = IIO_VOLTAGE, \
+ .indexed = 1, \
+ .output = 1, \
+ .channel = chan, \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),\
+ .address = AD5686_ADDR_DAC(chan), \
+ .scan_type = { \
+ .sign = 'u', \
+ .realbits = (bits), \
+ .storagebits = 16, \
+ .shift = (_shift), \
+ }, \
+ .ext_info = ad5686_ext_info, \
+}
+
+static const struct ad5686_chip_info ad5686_chip_info_tbl[] = {
+ [ID_AD5684] = {
+ .channel[0] = AD5868_CHANNEL(0, 12, 4),
+ .channel[1] = AD5868_CHANNEL(1, 12, 4),
+ .channel[2] = AD5868_CHANNEL(2, 12, 4),
+ .channel[3] = AD5868_CHANNEL(3, 12, 4),
+ .int_vref_mv = 2500,
+ },
+ [ID_AD5685] = {
+ .channel[0] = AD5868_CHANNEL(0, 14, 2),
+ .channel[1] = AD5868_CHANNEL(1, 14, 2),
+ .channel[2] = AD5868_CHANNEL(2, 14, 2),
+ .channel[3] = AD5868_CHANNEL(3, 14, 2),
+ .int_vref_mv = 2500,
+ },
+ [ID_AD5686] = {
+ .channel[0] = AD5868_CHANNEL(0, 16, 0),
+ .channel[1] = AD5868_CHANNEL(1, 16, 0),
+ .channel[2] = AD5868_CHANNEL(2, 16, 0),
+ .channel[3] = AD5868_CHANNEL(3, 16, 0),
+ .int_vref_mv = 2500,
+ },
+};
+
+
+static int ad5686_probe(struct spi_device *spi)
+{
+ struct ad5686_state *st;
+ struct iio_dev *indio_dev;
+ int ret, voltage_uv = 0;
+
+ indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
+ if (indio_dev == NULL)
+ return -ENOMEM;
+
+ st = iio_priv(indio_dev);
+ spi_set_drvdata(spi, indio_dev);
+
+ st->reg = devm_regulator_get_optional(&spi->dev, "vcc");
+ if (!IS_ERR(st->reg)) {
+ ret = regulator_enable(st->reg);
+ if (ret)
+ return ret;
+
+ ret = regulator_get_voltage(st->reg);
+ if (ret < 0)
+ goto error_disable_reg;
+
+ voltage_uv = ret;
+ }
+
+ st->chip_info =
+ &ad5686_chip_info_tbl[spi_get_device_id(spi)->driver_data];
+
+ if (voltage_uv)
+ st->vref_mv = voltage_uv / 1000;
+ else
+ st->vref_mv = st->chip_info->int_vref_mv;
+
+ st->spi = spi;
+
+ /* Set all the power down mode for all channels to 1K pulldown */
+ st->pwr_down_mode = 0x55;
+
+ indio_dev->dev.parent = &spi->dev;
+ indio_dev->name = spi_get_device_id(spi)->name;
+ indio_dev->info = &ad5686_info;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->channels = st->chip_info->channel;
+ indio_dev->num_channels = AD5686_DAC_CHANNELS;
+
+ ret = ad5686_spi_write(st, AD5686_CMD_INTERNAL_REFER_SETUP, 0,
+ !!voltage_uv, 0);
+ if (ret)
+ goto error_disable_reg;
+
+ ret = iio_device_register(indio_dev);
+ if (ret)
+ goto error_disable_reg;
+
+ return 0;
+
+error_disable_reg:
+ if (!IS_ERR(st->reg))
+ regulator_disable(st->reg);
+ return ret;
+}
+
+static int ad5686_remove(struct spi_device *spi)
+{
+ struct iio_dev *indio_dev = spi_get_drvdata(spi);
+ struct ad5686_state *st = iio_priv(indio_dev);
+
+ iio_device_unregister(indio_dev);
+ if (!IS_ERR(st->reg))
+ regulator_disable(st->reg);
+
+ return 0;
+}
+
+static const struct spi_device_id ad5686_id[] = {
+ {"ad5684", ID_AD5684},
+ {"ad5685", ID_AD5685},
+ {"ad5686", ID_AD5686},
+ {}
+};
+MODULE_DEVICE_TABLE(spi, ad5686_id);
+
+static struct spi_driver ad5686_driver = {
+ .driver = {
+ .name = "ad5686",
+ .owner = THIS_MODULE,
+ },
+ .probe = ad5686_probe,
+ .remove = ad5686_remove,
+ .id_table = ad5686_id,
+};
+module_spi_driver(ad5686_driver);
+
+MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
+MODULE_DESCRIPTION("Analog Devices AD5686/85/84 DAC");
+MODULE_LICENSE("GPL v2");
Code Review / kvmfornfv.git / blobdiff