| Message ID | 20241231132513.6944-3-apokusinski01@gmail.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | iio: magnetometer: add support for Si7210 | expand |
On Tue, 31 Dec 2024 14:25:13 +0100 Antoni Pokusinski <apokusinski01@gmail.com> wrote: > Silicon Labs Si7210 is an I2C Hall effect magnetic position and > temperature sensor. The driver supports the following functionalities: > * reading the temperature measurements > * reading the magnetic field measurements in a single-shot mode > * choosing the magnetic field measurement scale (20 or 200 mT) > > Signed-off-by: Antoni Pokusinski <apokusinski01@gmail.com> Hi Antoni A few comments inline. Main one is that I 'think' the scale for the temperature is off by 1000. I got a bit lost in the maths so may have that wrong. Jonathan > diff --git a/drivers/iio/magnetometer/si7210.c b/drivers/iio/magnetometer/si7210.c > new file mode 100644 > index 000000000000..3b9b5b9807fd > --- /dev/null > +++ b/drivers/iio/magnetometer/si7210.c > @@ -0,0 +1,412 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Silicon Labs Si7210 Hall Effect sensor driver > + * > + * Copyright (c) 2024 Antoni Pokusinski <apokusinski01@gmail.com> > + * > + * Datasheet: > + * https://www.silabs.com/documents/public/data-sheets/si7210-datasheet.pdf > + */ > + > +#include <linux/module.h> Order seems a bit random. Probably better to just go alphabetical. > +#include <linux/i2c.h> > +#include <linux/iio/iio.h> > +#include <linux/regmap.h> > +#include <linux/math64.h> > +#include <linux/mutex.h> > +struct si7210_data { > + struct i2c_client *client; > + struct regmap *regmap; > + struct mutex fetch_lock; > + struct mutex otp_lock; Even though somewhat obvious, each lock needs a comment on what data it is protecting. For the otp_lock I'm not sure you even needed as it is only used during probe. If that weren't the case, can you safely overlap fetch and otp? Is it worth that distinction, if not is one lock enough? > + s8 temp_offset; > + s8 temp_gain; > + s8 scale_20_a[A_REGS_COUNT]; > + s8 scale_200_a[A_REGS_COUNT]; > + u8 curr_scale; > +}; > + > +static const struct iio_chan_spec si7210_channels[] = { > + { > + .type = IIO_MAGN, > + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | > + BIT(IIO_CHAN_INFO_SCALE) | BIT(IIO_CHAN_INFO_OFFSET), > + }, > + { > + .type = IIO_TEMP, > + .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), > + } > +}; > + > +static int si7210_fetch_measurement(struct si7210_data *data, > + struct iio_chan_spec const *chan, > + u8 buf[2]) See below. May be worth treating this as a __be16? It is described in the datasheet as being made up of most significant and least significant bytes so that seems a logic cleanup. > +{ > + u8 dspsigsel = chan->type == IIO_MAGN ? 0 : 1; > + int ret; > + > + scoped_guard(mutex, &data->fetch_lock) { As below. guard(mutex) better here to reduce indent a little and indicate the lock is held for whole function. > + ret = regmap_update_bits(data->regmap, SI7210_REG_DSPSIGSEL, > + SI7210_MASK_DSPSIGSEL, dspsigsel); > + if (ret < 0) > + return ret; > + > + ret = regmap_update_bits(data->regmap, SI7210_REG_POWER_CTRL, > + SI7210_MASK_ONEBURST | SI7210_MASK_STOP, > + SI7210_MASK_ONEBURST & ~SI7210_MASK_STOP); > + if (ret < 0) > + return ret; > + > + /* Read the contents of the registers containing the result: DSPSIGM, DSPSIGL */ > + ret = regmap_bulk_read(data->regmap, SI7210_REG_DSPSIGM, buf, 2); > + if (ret < 0) > + return ret; > + } > + > + return 0; > +} > + > +static int si7210_read_raw(struct iio_dev *indio_dev, > + struct iio_chan_spec const *chan, > + int *val, int *val2, long mask) > +{ > + struct si7210_data *data = iio_priv(indio_dev); > + long long tmp; > + u8 dspsig[2]; > + int ret; > + > + switch (mask) { > + case IIO_CHAN_INFO_RAW: > + ret = si7210_fetch_measurement(data, chan, dspsig); > + if (ret < 0) > + return ret; > + > + *val = ((dspsig[0] & 0x7F) << 8) + dspsig[1]; Very nearly a simple endian get. Probably better to treat it like one anyway. *val = get_unaligned_be16(dpsig) & GENMASK(14, 0) > + return IIO_VAL_INT; > + case IIO_CHAN_INFO_SCALE: > + *val = 0; > + if (data->curr_scale == 20) > + *val2 = 1250; > + else /* data->curr_scale == 200 */ > + *val2 = 12500; > + return IIO_VAL_INT_PLUS_MICRO; > + case IIO_CHAN_INFO_OFFSET: > + *val = -16384; > + return IIO_VAL_INT; > + case IIO_CHAN_INFO_PROCESSED: > + ret = si7210_fetch_measurement(data, chan, dspsig); > + if (ret < 0) > + return ret; > + > + tmp = ((dspsig[0] & 0x7F) << 5) + (dspsig[1] >> 3); This may be appropriate as an endian read and FIELD_GET(). Perhaps not worth it except that the type for the fetch_measurements could then be a __be16 rather than what looks like unrelated u8 pair. Given the docs have this a most and least significant bytes that seems to make sense to me. > + tmp = (div_s64(-383 * tmp * tmp, 100) + (160940 * tmp - 279800000)); > + tmp = (1 + (data->temp_gain >> 11)) * tmp + 62500 * data->temp_offset; > + tmp -= 732600; This is form 0.222 * VDD, given you should have a regulator as per the binding feedback you should be able to query that voltage. > + > + *val = div_s64_rem(tmp, 1000000, val2); > + I think this is returning a value in degrees celsius? IIO ABI matches older hwmon on temperatures and is in milicelsius. (Documentation/ABI/testing/sysfs-bus-iio) Please check other units match the aABI. > + return IIO_VAL_INT_PLUS_MICRO; > + default: > + return -EINVAL; > + } > +} > + > +static int si7210_set_scale(struct si7210_data *data, unsigned int scale) > +{ > + s8 *a_otp_values; > + int ret; > + > + if (scale == 20) > + a_otp_values = data->scale_20_a; > + else if (scale == 200) > + a_otp_values = data->scale_200_a; > + else > + return -EINVAL; > + > + scoped_guard(mutex, &data->fetch_lock) { As below (though this one is a little less clear as it's mid way through the function). I would just used guard() > + /* Write the registers 0xCA - 0xCC*/ > + ret = regmap_bulk_write(data->regmap, SI7210_REG_A0, a_otp_values, 3); > + if (ret < 0) > + return ret; > + > + /* Write the registers 0xCE - 0xD0*/ > + ret = regmap_bulk_write(data->regmap, SI7210_REG_A3, &a_otp_values[3], 3); > + if (ret < 0) > + return ret; > + > + data->curr_scale = scale; > + } > + > + return 0; > +} > +static int si7210_read_otpreg_val(struct si7210_data *data, unsigned int otpreg, u8 *val) > +{ > + int ret; > + unsigned int otpdata; > + > + scoped_guard(mutex, &data->otp_lock) { As you hold the lock for the whole body, I would just use guard(mutex)(&datap->otp_lock); as then the indent of the rest will be reduced, slightly improving readability. > + ret = regmap_write(data->regmap, SI7210_REG_OTP_ADDR, otpreg); > + if (ret < 0) > + return ret; > + > + ret = regmap_update_bits(data->regmap, SI7210_REG_OTP_CTRL, > + SI7210_MASK_OTP_READ_EN, SI7210_MASK_OTP_READ_EN); > + if (ret < 0) > + return ret; > + > + ret = regmap_read(data->regmap, SI7210_REG_OTP_DATA, &otpdata); > + if (ret < 0) > + return ret; > + > + *val = (u8)otpdata; > + } > + > + return 0; > +} > + > +static int si7210_device_wake(struct si7210_data *data) > +{ > + /* According to the datasheet, the primary method to wake up a device is > + * to send an empty write. However this is not feasible using current API so we > + * use the other method i.e. read a single byte. The device should respond with 0xFF > + */ Comment syntax for IIO would make this /* * According to the datasheet, the primary method to wake up a * device is to send an empty write. However this is not feasible * using current API so we use the other method i.e. read a single * byte. The device should respond with 0xFF */ > + > + int ret = 0; > + > + ret = i2c_smbus_read_byte(data->client); > + if (ret < 0) > + return ret; > + > + if ((u8)ret != 0xFF) Why is the cast needed? > + return -EIO; > + > + return 0; > +} > + > +static int si7210_device_init(struct si7210_data *data) > +{ > + int ret; > + unsigned int i; > + > + ret = si7210_device_wake(data); > + if (ret < 0) > + return ret; > + > + usleep_range(1000, 1500); fsleep() preferred. It'll use slightly different range, but the aim of that function is we never need to care what exactly is set and consider if the margin is reasonable or not. > + > + ret = si7210_read_otpreg_val(data, SI7210_OTPREG_TMP_GAIN, &data->temp_gain); > + if (ret < 0) > + return ret; > + ret = si7210_read_otpreg_val(data, SI7210_OTPREG_TMP_OFF, &data->temp_offset); > + if (ret < 0) > + return ret; > + > + for (i = 0; i < A_REGS_COUNT; i++) { > + ret = si7210_read_otpreg_val(data, a20_otp_regs[i], &data->scale_20_a[i]); > + if (ret < 0) > + return ret; > + } > + for (i = 0; i < A_REGS_COUNT; i++) { > + ret = si7210_read_otpreg_val(data, a200_otp_regs[i], &data->scale_200_a[i]); > + if (ret < 0) > + return ret; > + } > + > + ret = regmap_update_bits(data->regmap, SI7210_REG_ARAUTOINC, > + SI7210_MASK_ARAUTOINC, SI7210_MASK_ARAUTOINC); > + if (ret < 0) > + return ret; > + > + return si7210_set_scale(data, 20); > +} > + > +static const struct iio_info si7210_info = { > + .read_raw = si7210_read_raw, > + .write_raw = si7210_write_raw, > +}; > + > +static int si7210_probe(struct i2c_client *client) > +{ > + struct si7210_data *data; > + struct iio_dev *indio_dev; > + int ret; > + > + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); > + if (!indio_dev) > + return -ENOMEM; > + > + data = iio_priv(indio_dev); > + i2c_set_clientdata(client, indio_dev); Is this used? If not don't set it. > + data->client = client; > + > + mutex_init(&data->fetch_lock); > + mutex_init(&data->otp_lock); > + > + data->regmap = devm_regmap_init_i2c(client, &si7210_regmap_conf); > + if (IS_ERR(data->regmap)) > + return dev_err_probe(&client->dev, PTR_ERR(data->regmap), > + "failed to register regmap\n"); > + > + indio_dev->name = dev_name(&client->dev); > + indio_dev->modes = INDIO_DIRECT_MODE; > + indio_dev->info = &si7210_info; > + indio_dev->channels = si7210_channels; > + indio_dev->num_channels = ARRAY_SIZE(si7210_channels); > + > + ret = si7210_device_init(data); > + if (ret) > + return dev_err_probe(&client->dev, ret, "device initialization failed\n"); Generally we try to keep the line length in IIO to traditional 80 chars unless there is a good readability reason to do otherwise. Here I'd wrap before the message. > + > + return devm_iio_device_register(&client->dev, indio_dev); > +} > + > +static const struct i2c_device_id si7210_id[] = { > + { "si7210", 0 }, Trivial: No real point in setting the 0 explicitly. > + { } > +}; > +MODULE_DEVICE_TABLE(i2c, si7210_id); > + > +static const struct of_device_id si7210_dt_ids[] = { > + { .compatible = "silabs,si7210" }, > + { } > +}; > +MODULE_DEVICE_TABLE(of, si7210_dt_ids); > + > +static struct i2c_driver si7210_driver = { > + .driver = { > + .name = "si7210", > + .of_match_table = si7210_dt_ids, > + }, > + .probe = si7210_probe, > + .id_table = si7210_id, Totally trivial but I'd not bother with tab alignment at all rather than mixing using it and not here. .probe = si7120_probe, etc is fine and avoids mess of realigning in future if something longer named turns up. > +}; > + > +module_i2c_driver(si7210_driver); > +MODULE_AUTHOR("Antoni Pokusinski <apokusinski01@gmail.com>"); > +MODULE_DESCRIPTION("Silicon Labs Si7210 Hall Effect sensor I2C driver"); > +MODULE_LICENSE("Dual BSD/GPL");
diff --git a/drivers/iio/magnetometer/Kconfig b/drivers/iio/magnetometer/Kconfig index 7177cd1d67cb..3debf1320ad1 100644 --- a/drivers/iio/magnetometer/Kconfig +++ b/drivers/iio/magnetometer/Kconfig @@ -235,6 +235,17 @@ config SENSORS_RM3100_SPI To compile this driver as a module, choose M here: the module will be called rm3100-spi. +config SI7210 + tristate "SI7210 Hall effect sensor" + depends on I2C + select REGMAP_I2C + help + Say Y here to add support for the SI7210 Hall effect sensor. + + This driver can also be compiled as a module. + To compile this driver as a module, choose M here: the module + will be called si7210. + config TI_TMAG5273 tristate "TI TMAG5273 Low-Power Linear 3D Hall-Effect Sensor" depends on I2C diff --git a/drivers/iio/magnetometer/Makefile b/drivers/iio/magnetometer/Makefile index 3e4c2ecd9adf..58f32a855494 100644 --- a/drivers/iio/magnetometer/Makefile +++ b/drivers/iio/magnetometer/Makefile @@ -31,6 +31,8 @@ obj-$(CONFIG_SENSORS_RM3100) += rm3100-core.o obj-$(CONFIG_SENSORS_RM3100_I2C) += rm3100-i2c.o obj-$(CONFIG_SENSORS_RM3100_SPI) += rm3100-spi.o +obj-$(CONFIG_SI7210) += si7210.o + obj-$(CONFIG_TI_TMAG5273) += tmag5273.o obj-$(CONFIG_YAMAHA_YAS530) += yamaha-yas530.o diff --git a/drivers/iio/magnetometer/si7210.c b/drivers/iio/magnetometer/si7210.c new file mode 100644 index 000000000000..3b9b5b9807fd --- /dev/null +++ b/drivers/iio/magnetometer/si7210.c @@ -0,0 +1,412 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Silicon Labs Si7210 Hall Effect sensor driver + * + * Copyright (c) 2024 Antoni Pokusinski <apokusinski01@gmail.com> + * + * Datasheet: + * https://www.silabs.com/documents/public/data-sheets/si7210-datasheet.pdf + */ + +#include <linux/module.h> +#include <linux/i2c.h> +#include <linux/iio/iio.h> +#include <linux/regmap.h> +#include <linux/math64.h> +#include <linux/mutex.h> + +/* Registers offsets and masks */ +#define SI7210_REG_DSPSIGM 0xC1 +#define SI7210_REG_DSPSIGL 0xC2 + +#define SI7210_MASK_DSPSIGSEL GENMASK(2, 0) +#define SI7210_REG_DSPSIGSEL 0xC3 + +#define SI7210_MASK_STOP BIT(1) +#define SI7210_MASK_ONEBURST BIT(2) +#define SI7210_REG_POWER_CTRL 0xC4 + +#define SI7210_MASK_ARAUTOINC BIT(0) +#define SI7210_REG_ARAUTOINC 0xC5 + +#define SI7210_REG_A0 0xCA +#define SI7210_REG_A1 0xCB +#define SI7210_REG_A2 0xCC +#define SI7210_REG_A3 0xCE +#define SI7210_REG_A4 0xCF +#define SI7210_REG_A5 0xD0 + +#define SI7210_REG_OTP_ADDR 0xE1 +#define SI7210_REG_OTP_DATA 0xE2 + +#define SI7210_MASK_OTP_READ_EN BIT(1) +#define SI7210_REG_OTP_CTRL 0xE3 + +/* OTP data registers offsets */ +#define SI7210_OTPREG_TMP_OFF 0x1D +#define SI7210_OTPREG_TMP_GAIN 0x1E + +#define SI7210_OTPREG_A0_20 0x21 +#define SI7210_OTPREG_A1_20 0x22 +#define SI7210_OTPREG_A2_20 0x23 +#define SI7210_OTPREG_A3_20 0x24 +#define SI7210_OTPREG_A4_20 0x25 +#define SI7210_OTPREG_A5_20 0x26 + +#define SI7210_OTPREG_A0_200 0x27 +#define SI7210_OTPREG_A1_200 0x28 +#define SI7210_OTPREG_A2_200 0x29 +#define SI7210_OTPREG_A3_200 0x2A +#define SI7210_OTPREG_A4_200 0x2B +#define SI7210_OTPREG_A5_200 0x2C + +#define A_REGS_COUNT 6 + +static const unsigned int a20_otp_regs[A_REGS_COUNT] = { + SI7210_OTPREG_A0_20, SI7210_OTPREG_A1_20, SI7210_OTPREG_A2_20, + SI7210_OTPREG_A3_20, SI7210_OTPREG_A4_20, SI7210_OTPREG_A5_20 +}; + +static const unsigned int a200_otp_regs[A_REGS_COUNT] = { + SI7210_OTPREG_A0_200, SI7210_OTPREG_A1_200, SI7210_OTPREG_A2_200, + SI7210_OTPREG_A3_200, SI7210_OTPREG_A4_200, SI7210_OTPREG_A5_200 +}; + +static const struct regmap_range si7210_read_reg_ranges[] = { + regmap_reg_range(SI7210_REG_DSPSIGM, SI7210_REG_ARAUTOINC), + regmap_reg_range(SI7210_REG_A0, SI7210_REG_A2), + regmap_reg_range(SI7210_REG_A3, SI7210_REG_A5), + regmap_reg_range(SI7210_REG_OTP_ADDR, SI7210_REG_OTP_CTRL), +}; + +static const struct regmap_access_table si7210_readable_regs = { + .yes_ranges = si7210_read_reg_ranges, + .n_yes_ranges = ARRAY_SIZE(si7210_read_reg_ranges), +}; + +static const struct regmap_range si7210_write_reg_ranges[] = { + regmap_reg_range(SI7210_REG_DSPSIGSEL, SI7210_REG_ARAUTOINC), + regmap_reg_range(SI7210_REG_A0, SI7210_REG_A2), + regmap_reg_range(SI7210_REG_A3, SI7210_REG_A5), + regmap_reg_range(SI7210_REG_OTP_ADDR, SI7210_REG_OTP_CTRL), +}; + +static const struct regmap_access_table si7210_writeable_regs = { + .yes_ranges = si7210_write_reg_ranges, + .n_yes_ranges = ARRAY_SIZE(si7210_write_reg_ranges), +}; + +static const struct regmap_range si7210_volatile_reg_ranges[] = { + regmap_reg_range(SI7210_REG_DSPSIGM, SI7210_REG_DSPSIGL), + regmap_reg_range(SI7210_REG_POWER_CTRL, SI7210_REG_POWER_CTRL), +}; + +static const struct regmap_access_table si7210_volatile_regs = { + .yes_ranges = si7210_volatile_reg_ranges, + .n_yes_ranges = ARRAY_SIZE(si7210_volatile_reg_ranges), +}; + +static const struct regmap_config si7210_regmap_conf = { + .reg_bits = 8, + .val_bits = 8, + .max_register = SI7210_REG_OTP_CTRL, + + .rd_table = &si7210_readable_regs, + .wr_table = &si7210_writeable_regs, + .volatile_table = &si7210_volatile_regs, +}; + +struct si7210_data { + struct i2c_client *client; + struct regmap *regmap; + struct mutex fetch_lock; + struct mutex otp_lock; + s8 temp_offset; + s8 temp_gain; + s8 scale_20_a[A_REGS_COUNT]; + s8 scale_200_a[A_REGS_COUNT]; + u8 curr_scale; +}; + +static const struct iio_chan_spec si7210_channels[] = { + { + .type = IIO_MAGN, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_SCALE) | BIT(IIO_CHAN_INFO_OFFSET), + }, + { + .type = IIO_TEMP, + .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), + } +}; + +static int si7210_fetch_measurement(struct si7210_data *data, + struct iio_chan_spec const *chan, + u8 buf[2]) +{ + u8 dspsigsel = chan->type == IIO_MAGN ? 0 : 1; + int ret; + + scoped_guard(mutex, &data->fetch_lock) { + ret = regmap_update_bits(data->regmap, SI7210_REG_DSPSIGSEL, + SI7210_MASK_DSPSIGSEL, dspsigsel); + if (ret < 0) + return ret; + + ret = regmap_update_bits(data->regmap, SI7210_REG_POWER_CTRL, + SI7210_MASK_ONEBURST | SI7210_MASK_STOP, + SI7210_MASK_ONEBURST & ~SI7210_MASK_STOP); + if (ret < 0) + return ret; + + /* Read the contents of the registers containing the result: DSPSIGM, DSPSIGL */ + ret = regmap_bulk_read(data->regmap, SI7210_REG_DSPSIGM, buf, 2); + if (ret < 0) + return ret; + } + + return 0; +} + +static int si7210_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, long mask) +{ + struct si7210_data *data = iio_priv(indio_dev); + long long tmp; + u8 dspsig[2]; + int ret; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + ret = si7210_fetch_measurement(data, chan, dspsig); + if (ret < 0) + return ret; + + *val = ((dspsig[0] & 0x7F) << 8) + dspsig[1]; + return IIO_VAL_INT; + case IIO_CHAN_INFO_SCALE: + *val = 0; + if (data->curr_scale == 20) + *val2 = 1250; + else /* data->curr_scale == 200 */ + *val2 = 12500; + return IIO_VAL_INT_PLUS_MICRO; + case IIO_CHAN_INFO_OFFSET: + *val = -16384; + return IIO_VAL_INT; + case IIO_CHAN_INFO_PROCESSED: + ret = si7210_fetch_measurement(data, chan, dspsig); + if (ret < 0) + return ret; + + tmp = ((dspsig[0] & 0x7F) << 5) + (dspsig[1] >> 3); + tmp = (div_s64(-383 * tmp * tmp, 100) + (160940 * tmp - 279800000)); + tmp = (1 + (data->temp_gain >> 11)) * tmp + 62500 * data->temp_offset; + tmp -= 732600; + + *val = div_s64_rem(tmp, 1000000, val2); + + return IIO_VAL_INT_PLUS_MICRO; + default: + return -EINVAL; + } +} + +static int si7210_set_scale(struct si7210_data *data, unsigned int scale) +{ + s8 *a_otp_values; + int ret; + + if (scale == 20) + a_otp_values = data->scale_20_a; + else if (scale == 200) + a_otp_values = data->scale_200_a; + else + return -EINVAL; + + scoped_guard(mutex, &data->fetch_lock) { + /* Write the registers 0xCA - 0xCC*/ + ret = regmap_bulk_write(data->regmap, SI7210_REG_A0, a_otp_values, 3); + if (ret < 0) + return ret; + + /* Write the registers 0xCE - 0xD0*/ + ret = regmap_bulk_write(data->regmap, SI7210_REG_A3, &a_otp_values[3], 3); + if (ret < 0) + return ret; + + data->curr_scale = scale; + } + + return 0; +} + +static int si7210_write_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int val, int val2, long mask) +{ + struct si7210_data *data = iio_priv(indio_dev); + unsigned int scale; + + switch (mask) { + case IIO_CHAN_INFO_SCALE: + if (val == 0 && val2 == 1250) + scale = 20; + else if (val == 0 && val2 == 12500) + scale = 200; + else + return -EINVAL; + + return si7210_set_scale(data, scale); + default: + return -EINVAL; + } +} + +static int si7210_read_otpreg_val(struct si7210_data *data, unsigned int otpreg, u8 *val) +{ + int ret; + unsigned int otpdata; + + scoped_guard(mutex, &data->otp_lock) { + ret = regmap_write(data->regmap, SI7210_REG_OTP_ADDR, otpreg); + if (ret < 0) + return ret; + + ret = regmap_update_bits(data->regmap, SI7210_REG_OTP_CTRL, + SI7210_MASK_OTP_READ_EN, SI7210_MASK_OTP_READ_EN); + if (ret < 0) + return ret; + + ret = regmap_read(data->regmap, SI7210_REG_OTP_DATA, &otpdata); + if (ret < 0) + return ret; + + *val = (u8)otpdata; + } + + return 0; +} + +static int si7210_device_wake(struct si7210_data *data) +{ + /* According to the datasheet, the primary method to wake up a device is + * to send an empty write. However this is not feasible using current API so we + * use the other method i.e. read a single byte. The device should respond with 0xFF + */ + + int ret = 0; + + ret = i2c_smbus_read_byte(data->client); + if (ret < 0) + return ret; + + if ((u8)ret != 0xFF) + return -EIO; + + return 0; +} + +static int si7210_device_init(struct si7210_data *data) +{ + int ret; + unsigned int i; + + ret = si7210_device_wake(data); + if (ret < 0) + return ret; + + usleep_range(1000, 1500); + + ret = si7210_read_otpreg_val(data, SI7210_OTPREG_TMP_GAIN, &data->temp_gain); + if (ret < 0) + return ret; + ret = si7210_read_otpreg_val(data, SI7210_OTPREG_TMP_OFF, &data->temp_offset); + if (ret < 0) + return ret; + + for (i = 0; i < A_REGS_COUNT; i++) { + ret = si7210_read_otpreg_val(data, a20_otp_regs[i], &data->scale_20_a[i]); + if (ret < 0) + return ret; + } + for (i = 0; i < A_REGS_COUNT; i++) { + ret = si7210_read_otpreg_val(data, a200_otp_regs[i], &data->scale_200_a[i]); + if (ret < 0) + return ret; + } + + ret = regmap_update_bits(data->regmap, SI7210_REG_ARAUTOINC, + SI7210_MASK_ARAUTOINC, SI7210_MASK_ARAUTOINC); + if (ret < 0) + return ret; + + return si7210_set_scale(data, 20); +} + +static const struct iio_info si7210_info = { + .read_raw = si7210_read_raw, + .write_raw = si7210_write_raw, +}; + +static int si7210_probe(struct i2c_client *client) +{ + struct si7210_data *data; + struct iio_dev *indio_dev; + int ret; + + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); + if (!indio_dev) + return -ENOMEM; + + data = iio_priv(indio_dev); + i2c_set_clientdata(client, indio_dev); + data->client = client; + + mutex_init(&data->fetch_lock); + mutex_init(&data->otp_lock); + + data->regmap = devm_regmap_init_i2c(client, &si7210_regmap_conf); + if (IS_ERR(data->regmap)) + return dev_err_probe(&client->dev, PTR_ERR(data->regmap), + "failed to register regmap\n"); + + indio_dev->name = dev_name(&client->dev); + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->info = &si7210_info; + indio_dev->channels = si7210_channels; + indio_dev->num_channels = ARRAY_SIZE(si7210_channels); + + ret = si7210_device_init(data); + if (ret) + return dev_err_probe(&client->dev, ret, "device initialization failed\n"); + + return devm_iio_device_register(&client->dev, indio_dev); +} + +static const struct i2c_device_id si7210_id[] = { + { "si7210", 0 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, si7210_id); + +static const struct of_device_id si7210_dt_ids[] = { + { .compatible = "silabs,si7210" }, + { } +}; +MODULE_DEVICE_TABLE(of, si7210_dt_ids); + +static struct i2c_driver si7210_driver = { + .driver = { + .name = "si7210", + .of_match_table = si7210_dt_ids, + }, + .probe = si7210_probe, + .id_table = si7210_id, +}; + +module_i2c_driver(si7210_driver); +MODULE_AUTHOR("Antoni Pokusinski <apokusinski01@gmail.com>"); +MODULE_DESCRIPTION("Silicon Labs Si7210 Hall Effect sensor I2C driver"); +MODULE_LICENSE("Dual BSD/GPL");
Silicon Labs Si7210 is an I2C Hall effect magnetic position and temperature sensor. The driver supports the following functionalities: * reading the temperature measurements * reading the magnetic field measurements in a single-shot mode * choosing the magnetic field measurement scale (20 or 200 mT) Signed-off-by: Antoni Pokusinski <apokusinski01@gmail.com> --- drivers/iio/magnetometer/Kconfig | 11 + drivers/iio/magnetometer/Makefile | 2 + drivers/iio/magnetometer/si7210.c | 412 ++++++++++++++++++++++++++++++ 3 files changed, 425 insertions(+) create mode 100644 drivers/iio/magnetometer/si7210.c