// 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #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_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 { 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 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 void ltc2664_dac_code_read(struct ltc2664_state *st, u32 chan, u32 input, u32 *code) { guard(mutex)(&st->lock); *code = st->channels[chan].raw[input]; } 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); switch (info) { case IIO_CHAN_INFO_RAW: ltc2664_dac_code_read(st, chan->channel, LTC2664_INPUT_A, val); 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); 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); ltc2664_dac_code_read(st, chan->channel, private, &val); 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", ®); 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, "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_array(child, "output-range-microamp", tmp, ARRAY_SIZE(tmp)); if (!ret) { chan->span = ltc2664_set_span(st, 0, tmp[1] / 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, <c2664_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 && ret != -ENODEV) return ret; st->vref_mv = ret > 0 ? ret / 1000 : chip_info->internal_vref_mv; ret = ltc2664_setup(st); if (ret) return ret; indio_dev->name = chip_info->name; indio_dev->info = <c2664_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)<c2664_chip }, { "ltc2672", (kernel_ulong_t)<c2672_chip }, { } }; MODULE_DEVICE_TABLE(spi, ltc2664_id); static const struct of_device_id ltc2664_of_id[] = { { .compatible = "adi,ltc2664", .data = <c2664_chip }, { .compatible = "adi,ltc2672", .data = <c2672_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 "); MODULE_AUTHOR("Kim Seer Paller "); MODULE_DESCRIPTION("Analog Devices LTC2664 and LTC2672 DAC"); MODULE_LICENSE("GPL");