[PATCH v4 5/5] iio: dac: ltc2664: Add driver for LTC2664 and LTC2672

Kim Seer Paller
2024-06-19T06:50:11Z

LTC2664 4 channel, 12-/16-Bit Voltage Output SoftSpan DAC
LTC2672 5 channel, 12-/16-Bit Current Output Softspan DAC

Co-developed-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Kim Seer Paller <kimseer.paller@analog.com>
---
MAINTAINERS | 1 +
drivers/iio/dac/Kconfig | 11 +
drivers/iio/dac/Makefile | 1 +
drivers/iio/dac/ltc2664.c | 755 ++++++++++++++++++++++++++++++++++++++
4 files changed, 768 insertions(+)
create mode 100644 drivers/iio/dac/ltc2664.c

diff --git a/MAINTAINERS b/MAINTAINERS
index f4a5b5bc8ccc..7a02d9a196fb 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -13082,6 +13082,7 @@ S: Supported
W: https://ez.analog.com/linux-software-drivers
F: Documentation/devicetree/bindings/iio/dac/adi,ltc2664.yaml
F: Documentation/devicetree/bindings/iio/dac/adi,ltc2672.yaml
+F: drivers/iio/dac/ltc2664.c

LTC2688 IIO DAC DRIVER
M: Nuno Sá <nuno.sa@analog.com>
diff --git a/drivers/iio/dac/Kconfig b/drivers/iio/dac/Kconfig
index fb48dddbcc20..3a7691db3998 100644
--- a/drivers/iio/dac/Kconfig
+++ b/drivers/iio/dac/Kconfig
@@ -371,6 +371,17 @@ config LTC2632
To compile this driver as a module, choose M here: the
module will be called ltc2632.

+config LTC2664
+ tristate "Analog Devices LTC2664 and LTC2672 DAC SPI driver"
+ depends on SPI
+ select REGMAP
+ help
+ Say yes here to build support for Analog Devices
+ LTC2664 and LTC2672 converters (DAC).
+
+ To compile this driver as a module, choose M here: the
+ module will be called ltc2664.
+
config M62332
tristate "Mitsubishi M62332 DAC driver"
depends on I2C
diff --git a/drivers/iio/dac/Makefile b/drivers/iio/dac/Makefile
index 8432a81a19dc..2cf148f16306 100644
--- a/drivers/iio/dac/Makefile
+++ b/drivers/iio/dac/Makefile
@@ -37,6 +37,7 @@ obj-$(CONFIG_DS4424) += ds4424.o
obj-$(CONFIG_LPC18XX_DAC) += lpc18xx_dac.o
obj-$(CONFIG_LTC1660) += ltc1660.o
obj-$(CONFIG_LTC2632) += ltc2632.o
+obj-$(CONFIG_LTC2664) += ltc2664.o
obj-$(CONFIG_LTC2688) += ltc2688.o
obj-$(CONFIG_M62332) += m62332.o
obj-$(CONFIG_MAX517) += max517.o
diff --git a/drivers/iio/dac/ltc2664.c b/drivers/iio/dac/ltc2664.c
new file mode 100644
index 000000000000..9b73b9c6a7a7
--- /dev/null
+++ b/drivers/iio/dac/ltc2664.c
@@ -0,0 +1,755 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * LTC2664 4 channel, 12-/16-Bit Voltage Output SoftSpan DAC driver
+ * LTC2672 5 channel, 12-/16-Bit Current Output Softspan DAC driver
+ *
+ * Copyright 2024 Analog Devices Inc.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/cleanup.h>
+#include <linux/device.h>
+#include <linux/gpio/consumer.h>
+#include <linux/iio/iio.h>
+#include <linux/kernel.h>
+#include <linux/math64.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/mutex.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+#include <linux/spi/spi.h>
+
+#define LTC2664_CMD_WRITE_N(n) (0x00 + (n))
+#define LTC2664_CMD_UPDATE_N(n) (0x10 + (n))
+#define LTC2664_CMD_WRITE_N_UPDATE_ALL 0x20
+#define LTC2664_CMD_WRITE_N_UPDATE_N(n) (0x30 + (n))
+#define LTC2664_CMD_POWER_DOWN_N(n) (0x40 + (n))
+#define LTC2664_CMD_POWER_DOWN_ALL 0x50
+#define LTC2664_CMD_SPAN_N(n) (0x60 + (n))
+#define LTC2664_CMD_CONFIG 0x70
+#define LTC2664_CMD_MUX 0xB0
+#define LTC2664_CMD_TOGGLE_SEL 0xC0
+#define LTC2664_CMD_GLOBAL_TOGGLE 0xD0
+#define LTC2664_CMD_NO_OPERATION 0xF0
+#define LTC2664_REF_DISABLE 0x0001
+#define LTC2664_MSPAN_SOFTSPAN 7
+
+#define LTC2672_MAX_CHANNEL 5
+#define LTC2672_MAX_SPAN 7
+#define LTC2672_SCALE_MULTIPLIER(n) (50 * BIT(n))
+
+enum ltc2664_ids {
+ LTC2664,
+ LTC2672,
+};
+
+enum {
+ LTC2664_SPAN_RANGE_0V_5V,
+ LTC2664_SPAN_RANGE_0V_10V,
+ LTC2664_SPAN_RANGE_M5V_5V,
+ LTC2664_SPAN_RANGE_M10V_10V,
+ LTC2664_SPAN_RANGE_M2V5_2V5,
+};
+
+enum {
+ LTC2664_INPUT_A,
+ LTC2664_INPUT_B,
+ LTC2664_INPUT_B_AVAIL,
+ LTC2664_POWERDOWN,
+ LTC2664_POWERDOWN_MODE,
+ LTC2664_TOGGLE_EN,
+ LTC2664_GLOBAL_TOGGLE,
+};
+
+static const u16 ltc2664_mspan_lut[8][2] = {
+ { LTC2664_SPAN_RANGE_M10V_10V, 32768 }, /* MPS2=0, MPS1=0, MSP0=0 (0)*/
+ { LTC2664_SPAN_RANGE_M5V_5V, 32768 }, /* MPS2=0, MPS1=0, MSP0=1 (1)*/
+ { LTC2664_SPAN_RANGE_M2V5_2V5, 32768 }, /* MPS2=0, MPS1=1, MSP0=0 (2)*/
+ { LTC2664_SPAN_RANGE_0V_10V, 0 }, /* MPS2=0, MPS1=1, MSP0=1 (3)*/
+ { LTC2664_SPAN_RANGE_0V_10V, 32768 }, /* MPS2=1, MPS1=0, MSP0=0 (4)*/
+ { LTC2664_SPAN_RANGE_0V_5V, 0 }, /* MPS2=1, MPS1=0, MSP0=1 (5)*/
+ { LTC2664_SPAN_RANGE_0V_5V, 32768 }, /* MPS2=1, MPS1=1, MSP0=0 (6)*/
+ { LTC2664_SPAN_RANGE_0V_5V, 0 } /* MPS2=1, MPS1=1, MSP0=1 (7)*/
+};
+
+struct ltc2664_state;
+
+struct ltc2664_chip_info {
+ enum ltc2664_ids id;
+ const char *name;
+ int (*scale_get)(const struct ltc2664_state *st, int c);
+ int (*offset_get)(const struct ltc2664_state *st, int c);
+ int measurement_type;
+ unsigned int num_channels;
+ const struct iio_chan_spec *iio_chan;
+ const int (*span_helper)[2];
+ unsigned int num_span;
+ unsigned int internal_vref_mv;
+ bool manual_span_support;
+ bool rfsadj_support;
+};
+
+struct ltc2664_chan {
+ /* indicates if the channel should be toggled */
+ bool toggle_chan;
+ /* indicates if the channel is in powered down state */
+ bool powerdown;
+ /* span code of the channel */
+ u8 span;
+ /* raw data of the current state of the chip registers (A/B) */
+ u16 raw[2];
+};
+
+struct ltc2664_state {
+ struct spi_device *spi;
+ struct regmap *regmap;
+ struct ltc2664_chan channels[LTC2672_MAX_CHANNEL];
+ /* lock to protect against multiple access to the device and shared data */
+ struct mutex lock;
+ const struct ltc2664_chip_info *chip_info;
+ struct iio_chan_spec *iio_channels;
+ int vref_mv;
+ u32 rfsadj_ohms;
+ u32 toggle_sel;
+ bool global_toggle;
+};
+
+static const int ltc2664_span_helper[][2] = {
+ { 0, 5000 },
+ { 0, 10000 },
+ { -5000, 5000 },
+ { -10000, 10000 },
+ { -2500, 2500 },
+};
+
+static const int ltc2672_span_helper[][2] = {
+ { 0, 0 },
+ { 0, 3125 },
+ { 0, 6250 },
+ { 0, 12500 },
+ { 0, 25000 },
+ { 0, 50000 },
+ { 0, 100000 },
+ { 0, 200000 },
+ { 0, 300000 },
+};
+
+static int ltc2664_scale_get(const struct ltc2664_state *st, int c)
+{
+ const struct ltc2664_chan *chan = &st->channels[c];
+ const int (*span_helper)[2] = st->chip_info->span_helper;
+ int span, fs;
+
+ span = chan->span;
+ if (span < 0)
+ return span;
+
+ fs = span_helper[span][1] - span_helper[span][0];
+
+ return fs * st->vref_mv / 2500;
+}
+
+static int ltc2672_scale_get(const struct ltc2664_state *st, int c)
+{
+ const struct ltc2664_chan *chan = &st->channels[c];
+ int span, fs;
+
+ span = chan->span - 1;
+ if (span < 0)
+ return span;
+
+ fs = 1000 * st->vref_mv;
+
+ if (span == LTC2672_MAX_SPAN)
+ return mul_u64_u32_div(4800, fs, st->rfsadj_ohms);
+
+ return mul_u64_u32_div(LTC2672_SCALE_MULTIPLIER(span), fs, st->rfsadj_ohms);
+}
+
+static int ltc2664_offset_get(const struct ltc2664_state *st, int c)
+{
+ const struct ltc2664_chan *chan = &st->channels[c];
+ int span;
+
+ span = chan->span;
+ if (span < 0)
+ return span;
+
+ if (st->chip_info->span_helper[span][0] < 0)
+ return -32768;
+
+ return 0;
+}
+
+static int ltc2664_dac_code_write(struct ltc2664_state *st, u32 chan, u32 input,
+ u16 code)
+{
+ struct ltc2664_chan *c = &st->channels[chan];
+ int ret, reg;
+
+ guard(mutex)(&st->lock);
+ /* select the correct input register to write to */
+ if (c->toggle_chan) {
+ ret = regmap_write(st->regmap, LTC2664_CMD_TOGGLE_SEL,
+ input << chan);
+ if (ret)
+ return ret;
+ }
+ /*
+ * If in toggle mode the dac should be updated by an
+ * external signal (or sw toggle) and not here.
+ */
+ if (st->toggle_sel & BIT(chan))
+ reg = LTC2664_CMD_WRITE_N(chan);
+ else
+ reg = LTC2664_CMD_WRITE_N_UPDATE_N(chan);
+
+ ret = regmap_write(st->regmap, reg, code);
+ if (ret)
+ return ret;
+
+ c->raw[input] = code;
+
+ if (c->toggle_chan) {
+ ret = regmap_write(st->regmap, LTC2664_CMD_TOGGLE_SEL,
+ st->toggle_sel);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
+static int ltc2664_dac_code_read(struct ltc2664_state *st, u32 chan, u32 input,
+ u32 *code)
+{
+ guard(mutex)(&st->lock);
+ *code = st->channels[chan].raw[input];
+
+ return 0;
+}
+
+static const int ltc2664_raw_range[] = { 0, 1, U16_MAX };
+
+static int ltc2664_read_avail(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ const int **vals, int *type, int *length,
+ long info)
+{
+ switch (info) {
+ case IIO_CHAN_INFO_RAW:
+ *vals = ltc2664_raw_range;
+ *type = IIO_VAL_INT;
+
+ return IIO_AVAIL_RANGE;
+ default:
+ return -EINVAL;
+ }
+}
+
+static int ltc2664_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, int *val,
+ int *val2, long info)
+{
+ struct ltc2664_state *st = iio_priv(indio_dev);
+ int ret;
+
+ switch (info) {
+ case IIO_CHAN_INFO_RAW:
+ ret = ltc2664_dac_code_read(st, chan->channel,
+ LTC2664_INPUT_A, val);
+ if (ret)
+ return ret;
+
+ return IIO_VAL_INT;
+ case IIO_CHAN_INFO_OFFSET:
+ *val = st->chip_info->offset_get(st, chan->channel);
+
+ return IIO_VAL_INT;
+ case IIO_CHAN_INFO_SCALE:
+ *val = st->chip_info->scale_get(st, chan->channel);
+
+ *val2 = 16;
+ return IIO_VAL_FRACTIONAL_LOG2;
+ default:
+ return -EINVAL;
+ }
+}
+
+static int ltc2664_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, int val,
+ int val2, long info)
+{
+ struct ltc2664_state *st = iio_priv(indio_dev);
+
+ switch (info) {
+ case IIO_CHAN_INFO_RAW:
+ if (val > U16_MAX || val < 0)
+ return -EINVAL;
+
+ return ltc2664_dac_code_write(st, chan->channel,
+ LTC2664_INPUT_A, val);
+ default:
+ return -EINVAL;
+ }
+}
+
+static ssize_t ltc2664_reg_bool_get(struct iio_dev *indio_dev,
+ uintptr_t private,
+ const struct iio_chan_spec *chan,
+ char *buf)
+{
+ struct ltc2664_state *st = iio_priv(indio_dev);
+ u32 val;
+
+ guard(mutex)(&st->lock);
+ switch (private) {
+ case LTC2664_POWERDOWN:
+ val = st->channels[chan->channel].powerdown;
+
+ return sysfs_emit(buf, "%u\n", val);
+ case LTC2664_POWERDOWN_MODE:
+ return sysfs_emit(buf, "42kohm_to_gnd\n");
+ case LTC2664_TOGGLE_EN:
+ val = !!(st->toggle_sel & BIT(chan->channel));
+
+ return sysfs_emit(buf, "%u\n", val);
+ case LTC2664_GLOBAL_TOGGLE:
+ val = st->global_toggle;
+
+ return sysfs_emit(buf, "%u\n", val);
+ default:
+ return -EINVAL;
+ }
+}
+
+static ssize_t ltc2664_reg_bool_set(struct iio_dev *indio_dev,
+ uintptr_t private,
+ const struct iio_chan_spec *chan,
+ const char *buf, size_t len)
+{
+ struct ltc2664_state *st = iio_priv(indio_dev);
+ int ret;
+ bool en;
+
+ ret = kstrtobool(buf, &en);
+ if (ret)
+ return ret;
+
+ guard(mutex)(&st->lock);
+ switch (private) {
+ case LTC2664_POWERDOWN:
+ ret = regmap_write(st->regmap,
+ en ? LTC2664_CMD_POWER_DOWN_N(chan->channel) :
+ LTC2664_CMD_UPDATE_N(chan->channel), en);
+ if (ret)
+ return ret;
+
+ st->channels[chan->channel].powerdown = en;
+
+ return len;
+ case LTC2664_TOGGLE_EN:
+ if (en)
+ st->toggle_sel |= BIT(chan->channel);
+ else
+ st->toggle_sel &= ~BIT(chan->channel);
+
+ ret = regmap_write(st->regmap, LTC2664_CMD_TOGGLE_SEL,
+ st->toggle_sel);
+ if (ret)
+ return ret;
+
+ return len;
+ case LTC2664_GLOBAL_TOGGLE:
+ ret = regmap_write(st->regmap, LTC2664_CMD_GLOBAL_TOGGLE, en);
+ if (ret)
+ return ret;
+
+ st->global_toggle = en;
+
+ return len;
+ default:
+ return -EINVAL;
+ }
+}
+
+static ssize_t ltc2664_dac_input_read(struct iio_dev *indio_dev,
+ uintptr_t private,
+ const struct iio_chan_spec *chan,
+ char *buf)
+{
+ struct ltc2664_state *st = iio_priv(indio_dev);
+ int ret;
+ u32 val;
+
+ if (private == LTC2664_INPUT_B_AVAIL)
+ return sysfs_emit(buf, "[%u %u %u]\n", ltc2664_raw_range[0],
+ ltc2664_raw_range[1],
+ ltc2664_raw_range[2] / 4);
+
+ ret = ltc2664_dac_code_read(st, chan->channel, private, &val);
+ if (ret)
+ return ret;
+
+ return sysfs_emit(buf, "%u\n", val);
+}
+
+static ssize_t ltc2664_dac_input_write(struct iio_dev *indio_dev,
+ uintptr_t private,
+ const struct iio_chan_spec *chan,
+ const char *buf, size_t len)
+{
+ struct ltc2664_state *st = iio_priv(indio_dev);
+ int ret;
+ u16 val;
+
+ if (private == LTC2664_INPUT_B_AVAIL)
+ return -EINVAL;
+
+ ret = kstrtou16(buf, 10, &val);
+ if (ret)
+ return ret;
+
+ ret = ltc2664_dac_code_write(st, chan->channel, private, val);
+ if (ret)
+ return ret;
+
+ return len;
+}
+
+static int ltc2664_reg_access(struct iio_dev *indio_dev,
+ unsigned int reg,
+ unsigned int writeval,
+ unsigned int *readval)
+{
+ struct ltc2664_state *st = iio_priv(indio_dev);
+
+ if (readval)
+ return -EOPNOTSUPP;
+
+ return regmap_write(st->regmap, reg, writeval);
+}
+
+#define LTC2664_CHAN_EXT_INFO(_name, _what, _shared, _read, _write) { \
+ .name = _name, \
+ .read = (_read), \
+ .write = (_write), \
+ .private = (_what), \
+ .shared = (_shared), \
+}
+
+/*
+ * For toggle mode we only expose the symbol attr (sw_toggle) in case a TGPx is
+ * not provided in dts.
+ */
+static const struct iio_chan_spec_ext_info ltc2664_toggle_sym_ext_info[] = {
+ LTC2664_CHAN_EXT_INFO("raw0", LTC2664_INPUT_A, IIO_SEPARATE,
+ ltc2664_dac_input_read, ltc2664_dac_input_write),
+ LTC2664_CHAN_EXT_INFO("raw1", LTC2664_INPUT_B, IIO_SEPARATE,
+ ltc2664_dac_input_read, ltc2664_dac_input_write),
+ LTC2664_CHAN_EXT_INFO("powerdown", LTC2664_POWERDOWN, IIO_SEPARATE,
+ ltc2664_reg_bool_get, ltc2664_reg_bool_set),
+ LTC2664_CHAN_EXT_INFO("powerdown_mode", LTC2664_POWERDOWN_MODE,
+ IIO_SEPARATE, ltc2664_reg_bool_get, NULL),
+ LTC2664_CHAN_EXT_INFO("symbol", LTC2664_GLOBAL_TOGGLE, IIO_SEPARATE,
+ ltc2664_reg_bool_get, ltc2664_reg_bool_set),
+ LTC2664_CHAN_EXT_INFO("toggle_en", LTC2664_TOGGLE_EN,
+ IIO_SEPARATE, ltc2664_reg_bool_get,
+ ltc2664_reg_bool_set),
+ { }
+};
+
+static const struct iio_chan_spec_ext_info ltc2664_ext_info[] = {
+ LTC2664_CHAN_EXT_INFO("powerdown", LTC2664_POWERDOWN, IIO_SEPARATE,
+ ltc2664_reg_bool_get, ltc2664_reg_bool_set),
+ LTC2664_CHAN_EXT_INFO("powerdown_mode", LTC2664_POWERDOWN_MODE,
+ IIO_SEPARATE, ltc2664_reg_bool_get, NULL),
+ { }
+};
+
+static const struct iio_chan_spec ltc2664_channel_template = {
+ .indexed = 1,
+ .output = 1,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_SCALE) |
+ BIT(IIO_CHAN_INFO_OFFSET) |
+ BIT(IIO_CHAN_INFO_RAW),
+ .info_mask_separate_available = BIT(IIO_CHAN_INFO_RAW),
+ .ext_info = ltc2664_ext_info,
+};
+
+static const struct ltc2664_chip_info ltc2664_chip = {
+ .name = "ltc2664",
+ .scale_get = ltc2664_scale_get,
+ .offset_get = ltc2664_offset_get,
+ .measurement_type = IIO_VOLTAGE,
+ .num_channels = 4,
+ .span_helper = ltc2664_span_helper,
+ .num_span = ARRAY_SIZE(ltc2664_span_helper),
+ .internal_vref_mv = 2500,
+ .manual_span_support = true,
+ .rfsadj_support = false,
+};
+
+static const struct ltc2664_chip_info ltc2672_chip = {
+ .name = "ltc2672",
+ .scale_get = ltc2672_scale_get,
+ .offset_get = ltc2664_offset_get,
+ .measurement_type = IIO_CURRENT,
+ .num_channels = 5,
+ .span_helper = ltc2672_span_helper,
+ .num_span = ARRAY_SIZE(ltc2672_span_helper),
+ .internal_vref_mv = 1250,
+ .manual_span_support = false,
+ .rfsadj_support = true,
+};
+
+static int ltc2664_set_span(const struct ltc2664_state *st, int min, int max,
+ int chan)
+{
+ const struct ltc2664_chip_info *chip_info = st->chip_info;
+ const int (*span_helper)[2] = chip_info->span_helper;
+ int span, ret;
+
+ for (span = 0; span < chip_info->num_span; span++) {
+ if (min == span_helper[span][0] && max == span_helper[span][1])
+ break;
+ }
+
+ if (span == chip_info->num_span)
+ return -EINVAL;
+
+ ret = regmap_write(st->regmap, LTC2664_CMD_SPAN_N(chan), span);
+ if (ret)
+ return ret;
+
+ return span;
+}
+
+static int ltc2664_channel_config(struct ltc2664_state *st)
+{
+ const struct ltc2664_chip_info *chip_info = st->chip_info;
+ struct device *dev = &st->spi->dev;
+ u32 reg, tmp[2], mspan;
+ int ret, span = 0;
+
+ mspan = LTC2664_MSPAN_SOFTSPAN;
+ ret = device_property_read_u32(dev, "adi,manual-span-operation-config",
+ &mspan);
+ if (!ret) {
+ if (!chip_info->manual_span_support)
+ return dev_err_probe(dev, -EINVAL,
+ "adi,manual-span-operation-config not supported\n");
+
+ if (mspan > ARRAY_SIZE(ltc2664_mspan_lut))
+ return dev_err_probe(dev, -EINVAL,
+ "adi,manual-span-operation-config not in range\n");
+ }
+
+ st->rfsadj_ohms = 20000;
+ ret = device_property_read_u32(dev, "adi,rfsadj-ohms", &st->rfsadj_ohms);
+ if (!ret) {
+ if (!chip_info->rfsadj_support)
+ return dev_err_probe(dev, -EINVAL,
+ "adi,rfsadj-ohms not supported\n");
+
+ if (st->rfsadj_ohms < 19000 || st->rfsadj_ohms > 41000)
+ return dev_err_probe(dev, -EINVAL,
+ "adi,rfsadj-ohms not in range\n");
+ }
+
+ device_for_each_child_node_scoped(dev, child) {
+ struct ltc2664_chan *chan;
+
+ ret = fwnode_property_read_u32(child, "reg", &reg);
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "Failed to get reg property\n");
+
+ if (reg >= chip_info->num_channels)
+ return dev_err_probe(dev, -EINVAL,
+ "reg bigger than: %d\n",
+ chip_info->num_channels);
+
+ chan = &st->channels[reg];
+
+ if (fwnode_property_read_bool(child, "adi,toggle-mode")) {
+ chan->toggle_chan = true;
+ /* assume sw toggle ABI */
+ st->iio_channels[reg].ext_info = ltc2664_toggle_sym_ext_info;
+
+ /*
+ * Clear IIO_CHAN_INFO_RAW bit as toggle channels expose
+ * out_voltage/current_raw{0|1} files.
+ */
+ __clear_bit(IIO_CHAN_INFO_RAW,
+ &st->iio_channels[reg].info_mask_separate);
+ }
+
+ chan->raw[0] = ltc2664_mspan_lut[mspan][1];
+ chan->raw[1] = ltc2664_mspan_lut[mspan][1];
+
+ chan->span = ltc2664_mspan_lut[mspan][0];
+
+ ret = fwnode_property_read_u32_array(child, "adi,output-range-microvolt",
+ tmp, ARRAY_SIZE(tmp));
+ if (!ret && mspan == LTC2664_MSPAN_SOFTSPAN) {
+ chan->span = ltc2664_set_span(st, tmp[0] / 1000,
+ tmp[1] / 1000, reg);
+ if (span < 0)
+ return dev_err_probe(dev, span,
+ "Failed to set span\n");
+
+ }
+
+ ret = fwnode_property_read_u32(child,
+ "adi,output-range-microamp",
+ &tmp[0]);
+ if (!ret) {
+ chan->span = ltc2664_set_span(st, 0, tmp[0] / 1000, reg);
+ if (span < 0)
+ return dev_err_probe(dev, span,
+ "Failed to set span\n");
+ }
+ }
+
+ return 0;
+}
+
+static int ltc2664_setup(struct ltc2664_state *st)
+{
+ const struct ltc2664_chip_info *chip_info = st->chip_info;
+ struct gpio_desc *gpio;
+ int ret, i;
+
+ /* If we have a clr/reset pin, use that to reset the chip. */
+ gpio = devm_gpiod_get_optional(&st->spi->dev, "reset", GPIOD_OUT_HIGH);
+ if (IS_ERR(gpio))
+ return dev_err_probe(&st->spi->dev, PTR_ERR(gpio),
+ "Failed to get reset gpio");
+ if (gpio) {
+ fsleep(1000);
+ gpiod_set_value_cansleep(gpio, 0);
+ }
+
+ /*
+ * Duplicate the default channel configuration as it can change during
+ * @ltc2664_channel_config()
+ */
+ st->iio_channels = devm_kcalloc(&st->spi->dev,
+ chip_info->num_channels,
+ sizeof(struct iio_chan_spec),
+ GFP_KERNEL);
+ if (!st->iio_channels)
+ return -ENOMEM;
+
+ for (i = 0; i < chip_info->num_channels; i++) {
+ st->iio_channels[i] = ltc2664_channel_template;
+ st->iio_channels[i].type = chip_info->measurement_type;
+ st->iio_channels[i].channel = i;
+ }
+
+ ret = ltc2664_channel_config(st);
+ if (ret)
+ return ret;
+
+ return regmap_set_bits(st->regmap, LTC2664_CMD_CONFIG, LTC2664_REF_DISABLE);
+}
+
+static const struct regmap_config ltc2664_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 16,
+ .max_register = LTC2664_CMD_NO_OPERATION,
+};
+
+static const struct iio_info ltc2664_info = {
+ .write_raw = ltc2664_write_raw,
+ .read_raw = ltc2664_read_raw,
+ .read_avail = ltc2664_read_avail,
+ .debugfs_reg_access = ltc2664_reg_access,
+};
+
+static int ltc2664_probe(struct spi_device *spi)
+{
+ static const char * const regulators[] = { "vcc", "iovcc", "v-neg" };
+ const struct ltc2664_chip_info *chip_info;
+ struct device *dev = &spi->dev;
+ struct iio_dev *indio_dev;
+ struct ltc2664_state *st;
+ int ret;
+
+ indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ st = iio_priv(indio_dev);
+ st->spi = spi;
+
+ chip_info = spi_get_device_match_data(spi);
+ if (!chip_info)
+ return -ENODEV;
+
+ st->chip_info = chip_info;
+
+ mutex_init(&st->lock);
+
+ st->regmap = devm_regmap_init_spi(spi, &ltc2664_regmap_config);
+ if (IS_ERR(st->regmap))
+ return dev_err_probe(dev, PTR_ERR(st->regmap),
+ "Failed to init regmap");
+
+ ret = devm_regulator_bulk_get_enable(dev, ARRAY_SIZE(regulators),
+ regulators);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to enable regulators\n");
+
+ ret = devm_regulator_get_enable_read_voltage(dev, "ref");
+ if (ret < 0)
+ return dev_err_probe(dev, ret, "Failed to get vref voltage\n");
+ else if (ret == -ENODEV)
+ st->vref_mv = chip_info->internal_vref_mv;
+ else
+ st->vref_mv = ret / 1000;
+
+ ret = ltc2664_setup(st);
+ if (ret)
+ return ret;
+
+ indio_dev->name = chip_info->name;
+ indio_dev->info = &ltc2664_info;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->channels = st->iio_channels;
+ indio_dev->num_channels = chip_info->num_channels;
+
+ return devm_iio_device_register(dev, indio_dev);
+}
+
+static const struct spi_device_id ltc2664_id[] = {
+ { "ltc2664", (kernel_ulong_t)&ltc2664_chip },
+ { "ltc2672", (kernel_ulong_t)&ltc2672_chip },
+ { }
+};
+MODULE_DEVICE_TABLE(spi, ltc2664_id);
+
+static const struct of_device_id ltc2664_of_id[] = {
+ { .compatible = "adi,ltc2664", .data = &ltc2664_chip },
+ { .compatible = "adi,ltc2672", .data = &ltc2672_chip },
+ { }
+};
+MODULE_DEVICE_TABLE(of, ltc2664_of_id);
+
+static struct spi_driver ltc2664_driver = {
+ .driver = {
+ .name = "ltc2664",
+ .of_match_table = ltc2664_of_id,
+ },
+ .probe = ltc2664_probe,
+ .id_table = ltc2664_id,
+};
+module_spi_driver(ltc2664_driver);
+
+MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
+MODULE_AUTHOR("Kim Seer Paller <kimseer.paller@analog.com>");
+MODULE_DESCRIPTION("Analog Devices LTC2664 and LTC2672 DAC");
+MODULE_LICENSE("GPL");
--
2.34.1