diff options
Diffstat (limited to 'drivers/hwmon/max77705-hwmon.c')
| -rw-r--r-- | drivers/hwmon/max77705-hwmon.c | 221 |
1 files changed, 221 insertions, 0 deletions
diff --git a/drivers/hwmon/max77705-hwmon.c b/drivers/hwmon/max77705-hwmon.c new file mode 100644 index 000000000000..990023e6474e --- /dev/null +++ b/drivers/hwmon/max77705-hwmon.c @@ -0,0 +1,221 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * MAX77705 voltage and current hwmon driver. + * + * Copyright (C) 2025 Dzmitry Sankouski <dsankouski@gmail.com> + */ + +#include <linux/err.h> +#include <linux/hwmon-sysfs.h> +#include <linux/hwmon.h> +#include <linux/kernel.h> +#include <linux/mfd/max77705-private.h> +#include <linux/platform_device.h> +#include <linux/regmap.h> + +struct channel_desc { + u8 reg; + u8 avg_reg; + const char *const label; + // register resolution. nano Volts for voltage, nano Amperes for current + u32 resolution; +}; + +static const struct channel_desc current_channel_desc[] = { + { + .reg = IIN_REG, + .label = "IIN_REG", + .resolution = 125000 + }, + { + .reg = ISYS_REG, + .avg_reg = AVGISYS_REG, + .label = "ISYS_REG", + .resolution = 312500 + } +}; + +static const struct channel_desc voltage_channel_desc[] = { + { + .reg = VBYP_REG, + .label = "VBYP_REG", + .resolution = 427246 + }, + { + .reg = VSYS_REG, + .label = "VSYS_REG", + .resolution = 156250 + } +}; + +static int max77705_read_and_convert(struct regmap *regmap, u8 reg, u32 res, + bool is_signed, long *val) +{ + int ret; + u32 regval; + + ret = regmap_read(regmap, reg, ®val); + if (ret < 0) + return ret; + + if (is_signed) + *val = mult_frac((long)sign_extend32(regval, 15), res, 1000000); + else + *val = mult_frac((long)regval, res, 1000000); + + return 0; +} + +static umode_t max77705_is_visible(const void *data, + enum hwmon_sensor_types type, + u32 attr, int channel) +{ + switch (type) { + case hwmon_in: + switch (attr) { + case hwmon_in_input: + case hwmon_in_label: + return 0444; + default: + break; + } + break; + case hwmon_curr: + switch (attr) { + case hwmon_curr_input: + case hwmon_in_label: + return 0444; + case hwmon_curr_average: + if (current_channel_desc[channel].avg_reg) + return 0444; + break; + default: + break; + } + break; + default: + break; + } + return 0; +} + +static int max77705_read_string(struct device *dev, enum hwmon_sensor_types type, u32 attr, + int channel, const char **buf) +{ + switch (type) { + case hwmon_curr: + switch (attr) { + case hwmon_in_label: + *buf = current_channel_desc[channel].label; + return 0; + default: + return -EOPNOTSUPP; + } + + case hwmon_in: + switch (attr) { + case hwmon_in_label: + *buf = voltage_channel_desc[channel].label; + return 0; + default: + return -EOPNOTSUPP; + } + default: + return -EOPNOTSUPP; + } +} + +static int max77705_read(struct device *dev, enum hwmon_sensor_types type, + u32 attr, int channel, long *val) +{ + struct regmap *regmap = dev_get_drvdata(dev); + u8 reg; + u32 res; + + switch (type) { + case hwmon_curr: + switch (attr) { + case hwmon_curr_input: + reg = current_channel_desc[channel].reg; + res = current_channel_desc[channel].resolution; + + return max77705_read_and_convert(regmap, reg, res, true, val); + case hwmon_curr_average: + reg = current_channel_desc[channel].avg_reg; + res = current_channel_desc[channel].resolution; + + return max77705_read_and_convert(regmap, reg, res, true, val); + default: + return -EOPNOTSUPP; + } + + case hwmon_in: + switch (attr) { + case hwmon_in_input: + reg = voltage_channel_desc[channel].reg; + res = voltage_channel_desc[channel].resolution; + + return max77705_read_and_convert(regmap, reg, res, false, val); + default: + return -EOPNOTSUPP; + } + default: + return -EOPNOTSUPP; + } + + return 0; +} + +static const struct hwmon_ops max77705_hwmon_ops = { + .is_visible = max77705_is_visible, + .read = max77705_read, + .read_string = max77705_read_string, +}; + +static const struct hwmon_channel_info *max77705_info[] = { + HWMON_CHANNEL_INFO(in, + HWMON_I_INPUT | HWMON_I_LABEL, + HWMON_I_INPUT | HWMON_I_LABEL + ), + HWMON_CHANNEL_INFO(curr, + HWMON_C_INPUT | HWMON_C_LABEL, + HWMON_C_INPUT | HWMON_C_AVERAGE | HWMON_C_LABEL + ), + NULL +}; + +static const struct hwmon_chip_info max77705_chip_info = { + .ops = &max77705_hwmon_ops, + .info = max77705_info, +}; + +static int max77705_hwmon_probe(struct platform_device *pdev) +{ + struct device *hwmon_dev; + struct regmap *regmap; + + regmap = dev_get_regmap(pdev->dev.parent, NULL); + if (!regmap) + return -ENODEV; + + hwmon_dev = devm_hwmon_device_register_with_info(&pdev->dev, "max77705", regmap, + &max77705_chip_info, NULL); + if (IS_ERR(hwmon_dev)) + return dev_err_probe(&pdev->dev, PTR_ERR(hwmon_dev), + "Unable to register hwmon device\n"); + + return 0; +}; + +static struct platform_driver max77705_hwmon_driver = { + .driver = { + .name = "max77705-hwmon", + }, + .probe = max77705_hwmon_probe, +}; + +module_platform_driver(max77705_hwmon_driver); + +MODULE_AUTHOR("Dzmitry Sankouski <dsankouski@gmail.com>"); +MODULE_DESCRIPTION("MAX77705 monitor driver"); +MODULE_LICENSE("GPL"); |