| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Vlad Kulikov | 1312 | 100.00% | 1 | 100.00% |
| Total | 1312 | 1 |
// SPDX-License-Identifier: GPL-2.0-only /* * MMC5983 - MEMSIC 3-axis Magnetic Sensor * * Copyright (c) 2026, Vlad Kulikov <vlad.kulikov.c@gmail.com> * * IIO driver for MMC5983 */ #include <linux/array_size.h> #include <linux/bits.h> #include <linux/cleanup.h> #include <linux/delay.h> #include <linux/dev_printk.h> #include <linux/err.h> #include <linux/i2c.h> #include <linux/iio/iio.h> #include <linux/module.h> #include <linux/mutex.h> #include <linux/regmap.h> #include <linux/time.h> #include <linux/types.h> #define MMC5983_REG_XOUT0 0x00 #define MMC5983_REG_XOUT1 0x01 #define MMC5983_REG_YOUT0 0x02 #define MMC5983_REG_YOUT1 0x03 #define MMC5983_REG_ZOUT0 0x04 #define MMC5983_REG_ZOUT1 0x05 #define MMC5983_REG_XYZOUT2 0x06 #define MMC5983_REG_STATUS 0x08 #define MMC5983_REG_CTRL0 0x09 #define MMC5983_REG_CTRL1 0x0A #define MMC5983_REG_CTRL2 0x0B #define MMC5983_REG_CTRL3 0x0C #define MMC5983_REG_ID 0x2F #define MMC5983_PRODUCT_ID 0x30 #define MMC5983_STATUS_MEAS_M_DONE_BIT BIT(0) #define MMC5983_STATUS_OTP_RD_DONE_BIT BIT(4) #define MMC5983_CTRL0_TM_M_BIT BIT(0) #define MMC5983_CTRL0_SET_BIT BIT(3) #define MMC5983_CTRL0_RESET_BIT BIT(4) #define MMC5983_CTRL0_OTP_RD_BIT BIT(6) #define MMC5983_CTRL1_SW_RST_BIT BIT(7) enum mmc5983_axis { MMC5983_AXIS_X, MMC5983_AXIS_Y, MMC5983_AXIS_Z, }; struct mmc5983_data { struct regmap *regmap; /* Protects chip access during SET/RESET measurement sequence */ struct mutex mutex; }; #define MMC5983_CHANNEL(_axis) { \ .type = IIO_MAGN, \ .modified = 1, \ .channel2 = IIO_MOD_##_axis, \ .address = MMC5983_AXIS_##_axis, \ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ } static const struct iio_chan_spec mmc5983_channels[] = { MMC5983_CHANNEL(X), MMC5983_CHANNEL(Y), MMC5983_CHANNEL(Z), }; static int mmc5983_pulse_coil(struct mmc5983_data *data, unsigned int coil_bit) { int ret; ret = regmap_write(data->regmap, MMC5983_REG_CTRL0, coil_bit); if (ret) return ret; /* * Datasheet page 15: SET/RESET coil pulse is 500 ns. * Vendor sample code waits 500 us before the next operation. */ fsleep(500); return 0; } static int mmc5983_take_measurement(struct mmc5983_data *data, int m[3]) { unsigned int status; u8 buf[7]; int ret; ret = regmap_write(data->regmap, MMC5983_REG_CTRL0, MMC5983_CTRL0_TM_M_BIT); if (ret) return ret; /* * Datasheet page 15: measurement time is 8 ms at BW=00 (default, * slowest setting). Use a 50 ms timeout for margin. */ ret = regmap_read_poll_timeout(data->regmap, MMC5983_REG_STATUS, status, status & MMC5983_STATUS_MEAS_M_DONE_BIT, 10 * USEC_PER_MSEC, 50 * USEC_PER_MSEC); if (ret) return ret; ret = regmap_bulk_read(data->regmap, MMC5983_REG_XOUT0, buf, sizeof(buf)); if (ret) return ret; m[0] = (buf[0] << 10) | (buf[1] << 2) | ((buf[6] >> 6) & 0x3); m[1] = (buf[2] << 10) | (buf[3] << 2) | ((buf[6] >> 4) & 0x3); m[2] = (buf[4] << 10) | (buf[5] << 2) | ((buf[6] >> 2) & 0x3); return 0; } static int mmc5983_read_raw(struct iio_dev *indio_dev, const struct iio_chan_spec *chan, int *val, int *val2, long mask) { struct mmc5983_data *data = iio_priv(indio_dev); int m1[3], m2[3]; int ret; switch (mask) { case IIO_CHAN_INFO_RAW: { guard(mutex)(&data->mutex); /* SET: magnetize sensor elements in forward direction */ ret = mmc5983_pulse_coil(data, MMC5983_CTRL0_SET_BIT); if (ret) return ret; ret = mmc5983_take_measurement(data, m1); if (ret) return ret; /* RESET: magnetize sensor elements in reverse direction */ ret = mmc5983_pulse_coil(data, MMC5983_CTRL0_RESET_BIT); if (ret) return ret; ret = mmc5983_take_measurement(data, m2); if (ret) return ret; *val = (m1[chan->address] - m2[chan->address]) / 2; return IIO_VAL_INT; } case IIO_CHAN_INFO_SCALE: *val = 0; *val2 = 61035; return IIO_VAL_INT_PLUS_NANO; default: return -EINVAL; } } static const struct iio_info mmc5983_info = { .read_raw = mmc5983_read_raw, }; static bool mmc5983_is_writeable_reg(struct device *dev, unsigned int reg) { switch (reg) { case MMC5983_REG_CTRL0: case MMC5983_REG_CTRL1: case MMC5983_REG_CTRL2: case MMC5983_REG_CTRL3: return true; default: return false; } } static bool mmc5983_is_readable_reg(struct device *dev, unsigned int reg) { switch (reg) { case MMC5983_REG_XOUT0: case MMC5983_REG_XOUT1: case MMC5983_REG_YOUT0: case MMC5983_REG_YOUT1: case MMC5983_REG_ZOUT0: case MMC5983_REG_ZOUT1: case MMC5983_REG_XYZOUT2: case MMC5983_REG_STATUS: case MMC5983_REG_CTRL0: case MMC5983_REG_CTRL1: case MMC5983_REG_CTRL2: case MMC5983_REG_CTRL3: case MMC5983_REG_ID: return true; default: return false; } } static bool mmc5983_is_volatile_reg(struct device *dev, unsigned int reg) { switch (reg) { case MMC5983_REG_XOUT0: case MMC5983_REG_XOUT1: case MMC5983_REG_YOUT0: case MMC5983_REG_YOUT1: case MMC5983_REG_ZOUT0: case MMC5983_REG_ZOUT1: case MMC5983_REG_XYZOUT2: case MMC5983_REG_STATUS: case MMC5983_REG_CTRL0: case MMC5983_REG_CTRL1: return true; default: return false; } } static const struct regmap_config mmc5983_regmap_config = { .name = "mmc5983_regmap", .reg_bits = 8, .val_bits = 8, .max_register = MMC5983_REG_ID, .writeable_reg = mmc5983_is_writeable_reg, .readable_reg = mmc5983_is_readable_reg, .volatile_reg = mmc5983_is_volatile_reg, }; static int mmc5983_init(struct mmc5983_data *data) { struct regmap *regmap = data->regmap; struct device *dev = regmap_get_device(regmap); unsigned int reg_id, status; int ret; ret = regmap_read(regmap, MMC5983_REG_ID, ®_id); if (ret) return dev_err_probe(dev, ret, "Error reading product id\n"); if (reg_id != MMC5983_PRODUCT_ID) dev_info(dev, "unexpected product id 0x%02x\n", reg_id); ret = regmap_write(regmap, MMC5983_REG_CTRL1, MMC5983_CTRL1_SW_RST_BIT); if (ret) return ret; /* Datasheet page 15: power-on time after SW_RST is 10 ms */ fsleep(10 * USEC_PER_MSEC); ret = regmap_write(regmap, MMC5983_REG_CTRL0, MMC5983_CTRL0_OTP_RD_BIT); if (ret) return ret; /* * Datasheet page 15: OTP read completes and self-clears. No separate * OTP refresh timeout is specified, so use the 10 ms power-on time as * a conservative upper bound. */ ret = regmap_read_poll_timeout(regmap, MMC5983_REG_STATUS, status, status & MMC5983_STATUS_OTP_RD_DONE_BIT, USEC_PER_MSEC, 10 * USEC_PER_MSEC); if (ret) return ret; /* SET: magnetize sensor elements in forward direction */ ret = mmc5983_pulse_coil(data, MMC5983_CTRL0_SET_BIT); if (ret) return ret; /* RESET: magnetize sensor elements in reverse direction */ return mmc5983_pulse_coil(data, MMC5983_CTRL0_RESET_BIT); } static int mmc5983_probe(struct i2c_client *i2c) { struct device *dev = &i2c->dev; struct mmc5983_data *data; struct iio_dev *indio_dev; int ret; indio_dev = devm_iio_device_alloc(dev, sizeof(*data)); if (!indio_dev) return -ENOMEM; data = iio_priv(indio_dev); ret = devm_mutex_init(dev, &data->mutex); if (ret) return ret; data->regmap = devm_regmap_init_i2c(i2c, &mmc5983_regmap_config); if (IS_ERR(data->regmap)) return dev_err_probe(dev, PTR_ERR(data->regmap), "failed to allocate register map\n"); indio_dev->info = &mmc5983_info; indio_dev->modes = INDIO_DIRECT_MODE; indio_dev->name = "mmc5983"; indio_dev->channels = mmc5983_channels; indio_dev->num_channels = ARRAY_SIZE(mmc5983_channels); ret = mmc5983_init(data); if (ret) return dev_err_probe(dev, ret, "mmc5983 chip init failed\n"); return devm_iio_device_register(dev, indio_dev); } static const struct of_device_id mmc5983_of_match[] = { { .compatible = "memsic,mmc5983" }, { } }; MODULE_DEVICE_TABLE(of, mmc5983_of_match); static const struct i2c_device_id mmc5983_id[] = { { "mmc5983" }, { } }; MODULE_DEVICE_TABLE(i2c, mmc5983_id); static struct i2c_driver mmc5983_driver = { .driver = { .name = "mmc5983", .of_match_table = mmc5983_of_match, }, .probe = mmc5983_probe, .id_table = mmc5983_id, }; module_i2c_driver(mmc5983_driver); MODULE_AUTHOR("Vladislav Kulikov <vlad.kulikov.c@gmail.com>"); MODULE_DESCRIPTION("MEMSIC MMC5983 magnetic sensor driver"); MODULE_LICENSE("GPL");
Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.
Created with Cregit http://github.com/cregit/cregit
Version 2.0-RC1