147 lines
3.4 KiB
C
147 lines
3.4 KiB
C
/*
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* Driver for Linear Technology LTC1660/LTC1665 DAC
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*
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* Copyright (C) 2023 Marcus Folkesson <marcus.folkesson@gmail.com>
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*
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* SPDX-License-Identifier: Apache-2.0
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*/
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#include <zephyr/kernel.h>
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#include <zephyr/drivers/spi.h>
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#include <zephyr/drivers/dac.h>
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#include <zephyr/logging/log.h>
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LOG_MODULE_REGISTER(dac_ltc166x, CONFIG_DAC_LOG_LEVEL);
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#define LTC166X_REG_MASK GENMASK(15, 12)
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#define LTC166X_DATA8_MASK GENMASK(11, 4)
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#define LTC166X_DATA10_MASK GENMASK(12, 2)
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struct ltc166x_config {
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struct spi_dt_spec bus;
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uint8_t resolution;
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uint8_t nchannels;
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};
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static int ltc166x_reg_write(const struct device *dev, uint8_t addr,
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uint32_t data)
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{
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const struct ltc166x_config *config = dev->config;
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uint16_t regval;
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regval = FIELD_PREP(LTC166X_REG_MASK, addr);
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if (config->resolution == 10) {
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regval |= FIELD_PREP(LTC166X_DATA10_MASK, data);
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} else {
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regval |= FIELD_PREP(LTC166X_DATA8_MASK, data);
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}
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const struct spi_buf buf = {
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.buf = ®val,
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.len = sizeof(regval),
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};
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struct spi_buf_set tx = {
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.buffers = &buf,
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.count = 1,
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};
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return spi_write_dt(&config->bus, &tx);
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}
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static int ltc166x_channel_setup(const struct device *dev,
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const struct dac_channel_cfg *channel_cfg)
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{
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const struct ltc166x_config *config = dev->config;
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if (channel_cfg->channel_id > config->nchannels - 1) {
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LOG_ERR("Unsupported channel %d", channel_cfg->channel_id);
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return -ENOTSUP;
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}
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if (channel_cfg->resolution != config->resolution) {
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LOG_ERR("Unsupported resolution %d", channel_cfg->resolution);
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return -ENOTSUP;
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}
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if (channel_cfg->internal) {
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LOG_ERR("Internal channels not supported");
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return -ENOTSUP;
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}
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return 0;
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}
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static int ltc166x_write_value(const struct device *dev, uint8_t channel,
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uint32_t value)
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{
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const struct ltc166x_config *config = dev->config;
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if (channel > config->nchannels - 1) {
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LOG_ERR("unsupported channel %d", channel);
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return -ENOTSUP;
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}
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if (value >= (1 << config->resolution)) {
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LOG_ERR("Value %d out of range", value);
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return -EINVAL;
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}
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return ltc166x_reg_write(dev, channel + 1, value);
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}
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static int ltc166x_init(const struct device *dev)
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{
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const struct ltc166x_config *config = dev->config;
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if (!spi_is_ready_dt(&config->bus)) {
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LOG_ERR("SPI bus %s not ready", config->bus.bus->name);
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return -ENODEV;
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}
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return 0;
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}
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static const struct dac_driver_api ltc166x_driver_api = {
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.channel_setup = ltc166x_channel_setup,
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.write_value = ltc166x_write_value,
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};
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#define INST_DT_LTC166X(inst, t) DT_INST(inst, lltc_ltc##t)
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#define LTC166X_DEVICE(t, n, res, nchan) \
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static const struct ltc166x_config ltc##t##_config_##n = { \
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.bus = SPI_DT_SPEC_GET(INST_DT_LTC166X(n, t), \
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SPI_OP_MODE_MASTER | \
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SPI_WORD_SET(8), 0), \
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.resolution = res, \
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.nchannels = nchan, \
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}; \
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DEVICE_DT_DEFINE(INST_DT_LTC166X(n, t), \
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<c166x_init, NULL, \
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NULL, \
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<c##t##_config_##n, POST_KERNEL, \
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CONFIG_DAC_LTC166X_INIT_PRIORITY, \
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<c166x_driver_api)
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/*
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* LTC1660: 10-bit
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*/
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#define LTC1660_DEVICE(n) LTC166X_DEVICE(1660, n, 10, 8)
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/*
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* LTC1665: 8-bit
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*/
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#define LTC1665_DEVICE(n) LTC166X_DEVICE(1665, n, 8, 8)
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#define CALL_WITH_ARG(arg, expr) expr(arg)
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#define INST_DT_LTC166X_FOREACH(t, inst_expr) \
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LISTIFY(DT_NUM_INST_STATUS_OKAY(lltc_ltc##t), \
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CALL_WITH_ARG, (), inst_expr)
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INST_DT_LTC166X_FOREACH(1660, LTC1660_DEVICE);
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INST_DT_LTC166X_FOREACH(1665, LTC1665_DEVICE);
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