9da5538f92
Since this DAC is connected via I2C bus the init priority value must be higher than the default 50 so it can be initialized later than the bus itself so add a dedicated init config symbol for that. Signed-off-by: Bartosz Bilas <b.bilas@grinn-global.com>
111 lines
3.2 KiB
C
111 lines
3.2 KiB
C
/*
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* Copyright 2021 Grinn
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*
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* SPDX-License-Identifier: Apache-2.0
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*/
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#define DT_DRV_COMPAT microchip_mcp4728
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#include <zephyr/zephyr.h>
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#include <zephyr/drivers/dac.h>
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#include <zephyr/drivers/i2c.h>
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#include <zephyr/logging/log.h>
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LOG_MODULE_REGISTER(dac_mcp4728, CONFIG_DAC_LOG_LEVEL);
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#define MCP4728_MAX_CHANNEL 4U
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#define MCP4728_RESOLUTION 0xC
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#define MCP4728_DAC_MAX_VAL ((1U << MCP4728_RESOLUTION) - 1U)
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#define MCP4728_MULTI_WRITE_CMD_VAL 8U
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#define MCP4728_MULTI_WRITE_CMD_POS 3U
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#define MCP4728_MULTI_WRITE_CHANNEL_POS 1U
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#define MCP4728_MULTI_WRITE_REFERENCE_POS 7U
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#define MCP4728_MULTI_WRITE_POWER_DOWN_POS 5U
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#define MCP4728_MULTI_WRITE_POWER_DOWN_MASK 0X3
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#define MCP4728_MULTI_WRITE_GAIN_POS 4U
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#define MCP4728_MULTI_WRITE_DAC_UPPER_VAL_POS 8U
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#define MCP4728_MULTI_WRITE_DAC_UPPER_VAL_MASK 0xF
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#define MCP4728_MULTI_WRITE_DAC_LOWER_VAL_MASK 0xFF
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struct mcp4728_config {
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struct i2c_dt_spec bus;
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uint8_t power_down[MCP4728_MAX_CHANNEL];
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uint8_t voltage_reference[MCP4728_MAX_CHANNEL];
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uint8_t gain[MCP4728_MAX_CHANNEL];
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};
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static int mcp4728_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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if (channel_cfg->channel_id >= MCP4728_MAX_CHANNEL) {
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return -ENOTSUP;
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}
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if (channel_cfg->resolution != MCP4728_RESOLUTION) {
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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 mcp4728_write_value(const struct device *dev, uint8_t channel, uint32_t value)
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{
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const struct mcp4728_config *config = (struct mcp4728_config *)dev->config;
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uint8_t tx_data[3];
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int ret;
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if (channel >= MCP4728_MAX_CHANNEL) {
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return -ENOTSUP;
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}
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if (value > MCP4728_DAC_MAX_VAL) {
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return -ENOTSUP;
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}
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/* Multi-Write Command: Write Multiple DAC Input Registers. */
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tx_data[0] = (MCP4728_MULTI_WRITE_CMD_VAL << MCP4728_MULTI_WRITE_CMD_POS) |
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(channel << MCP4728_MULTI_WRITE_CHANNEL_POS);
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tx_data[1] = (config->voltage_reference[channel] << MCP4728_MULTI_WRITE_REFERENCE_POS) |
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((config->power_down[channel] & MCP4728_MULTI_WRITE_POWER_DOWN_MASK)
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<< MCP4728_MULTI_WRITE_POWER_DOWN_POS) |
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((config->gain[channel] << MCP4728_MULTI_WRITE_GAIN_POS)) |
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((value >> MCP4728_MULTI_WRITE_DAC_UPPER_VAL_POS) &
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MCP4728_MULTI_WRITE_DAC_UPPER_VAL_MASK);
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tx_data[2] = (value & MCP4728_MULTI_WRITE_DAC_LOWER_VAL_MASK);
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ret = i2c_write_dt(&config->bus, tx_data, sizeof(tx_data));
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return ret;
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}
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static int dac_mcp4728_init(const struct device *dev)
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{
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const struct mcp4728_config *config = dev->config;
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if (!device_is_ready(config->bus.bus)) {
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LOG_ERR("%s device not found", 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 mcp4728_driver_api = {
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.channel_setup = mcp4728_channel_setup,
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.write_value = mcp4728_write_value,
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};
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#define INST_DT_MCP4728(index) \
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static const struct mcp4728_config mcp4728_config_##index = { \
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.bus = I2C_DT_SPEC_INST_GET(index), \
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.power_down = DT_INST_PROP(index, power_down_mode), \
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.voltage_reference = DT_INST_PROP(index, voltage_reference), \
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.gain = DT_INST_PROP_OR(index, gain, {0}), \
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}; \
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\
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DEVICE_DT_INST_DEFINE(index, dac_mcp4728_init, NULL, NULL, \
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&mcp4728_config_##index, \
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POST_KERNEL, \
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CONFIG_DAC_MCP4728_INIT_PRIORITY, \
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&mcp4728_driver_api);
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DT_INST_FOREACH_STATUS_OKAY(INST_DT_MCP4728);
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