zephyr/drivers/dac/dac_mcp4728.c

111 lines
3.2 KiB
C

/*
* Copyright 2021 Grinn
*
* SPDX-License-Identifier: Apache-2.0
*/
#define DT_DRV_COMPAT microchip_mcp4728
#include <zephyr.h>
#include <drivers/dac.h>
#include <drivers/i2c.h>
#include <logging/log.h>
LOG_MODULE_REGISTER(dac_mcp4728, CONFIG_DAC_LOG_LEVEL);
#define MCP4728_MAX_CHANNEL 4U
#define MCP4728_RESOLUTION 0xC
#define MCP4728_DAC_MAX_VAL ((1U << MCP4728_RESOLUTION) - 1U)
#define MCP4728_MULTI_WRITE_CMD_VAL 8U
#define MCP4728_MULTI_WRITE_CMD_POS 3U
#define MCP4728_MULTI_WRITE_CHANNEL_POS 1U
#define MCP4728_MULTI_WRITE_REFERENCE_POS 7U
#define MCP4728_MULTI_WRITE_POWER_DOWN_POS 5U
#define MCP4728_MULTI_WRITE_POWER_DOWN_MASK 0X3
#define MCP4728_MULTI_WRITE_GAIN_POS 4U
#define MCP4728_MULTI_WRITE_DAC_UPPER_VAL_POS 8U
#define MCP4728_MULTI_WRITE_DAC_UPPER_VAL_MASK 0xF
#define MCP4728_MULTI_WRITE_DAC_LOWER_VAL_MASK 0xFF
struct mcp4728_config {
struct i2c_dt_spec bus;
uint8_t power_down[MCP4728_MAX_CHANNEL];
uint8_t voltage_reference[MCP4728_MAX_CHANNEL];
uint8_t gain[MCP4728_MAX_CHANNEL];
};
static int mcp4728_channel_setup(const struct device *dev,
const struct dac_channel_cfg *channel_cfg)
{
if (channel_cfg->channel_id >= MCP4728_MAX_CHANNEL) {
return -ENOTSUP;
}
if (channel_cfg->resolution != MCP4728_RESOLUTION) {
return -ENOTSUP;
}
return 0;
}
static int mcp4728_write_value(const struct device *dev, uint8_t channel, uint32_t value)
{
const struct mcp4728_config *config = (struct mcp4728_config *)dev->config;
uint8_t tx_data[3];
int ret;
if (channel >= MCP4728_MAX_CHANNEL) {
return -ENOTSUP;
}
if (value > MCP4728_DAC_MAX_VAL) {
return -ENOTSUP;
}
/* Multi-Write Command: Write Multiple DAC Input Registers. */
tx_data[0] = (MCP4728_MULTI_WRITE_CMD_VAL << MCP4728_MULTI_WRITE_CMD_POS) |
(channel << MCP4728_MULTI_WRITE_CHANNEL_POS);
tx_data[1] = (config->voltage_reference[channel] << MCP4728_MULTI_WRITE_REFERENCE_POS) |
((config->power_down[channel] & MCP4728_MULTI_WRITE_POWER_DOWN_MASK)
<< MCP4728_MULTI_WRITE_POWER_DOWN_POS) |
((config->gain[channel] << MCP4728_MULTI_WRITE_GAIN_POS)) |
((value >> MCP4728_MULTI_WRITE_DAC_UPPER_VAL_POS) &
MCP4728_MULTI_WRITE_DAC_UPPER_VAL_MASK);
tx_data[2] = (value & MCP4728_MULTI_WRITE_DAC_LOWER_VAL_MASK);
ret = i2c_write_dt(&config->bus, tx_data, sizeof(tx_data));
return ret;
}
static int dac_mcp4728_init(const struct device *dev)
{
const struct mcp4728_config *config = dev->config;
if (!device_is_ready(config->bus.bus)) {
LOG_ERR("%s device not found", config->bus.bus->name);
return -ENODEV;
}
return 0;
}
static const struct dac_driver_api mcp4728_driver_api = {
.channel_setup = mcp4728_channel_setup,
.write_value = mcp4728_write_value,
};
#define INST_DT_MCP4728(index) \
static const struct mcp4728_config mcp4728_config_##index = { \
.bus = I2C_DT_SPEC_INST_GET(index), \
.power_down = DT_INST_PROP(index, power_down_mode), \
.voltage_reference = DT_INST_PROP(index, voltage_reference), \
.gain = DT_INST_PROP_OR(index, gain, {0}), \
}; \
\
DEVICE_DT_INST_DEFINE(index, dac_mcp4728_init, NULL, NULL, \
&mcp4728_config_##index, \
POST_KERNEL, \
CONFIG_DAC_INIT_PRIORITY, \
&mcp4728_driver_api);
DT_INST_FOREACH_STATUS_OKAY(INST_DT_MCP4728);