// SPDX-License-Identifier: GPL-2.0-only /* * IIO accel core driver for Freescale MMA7455L 3-axis 10-bit accelerometer * Copyright 2015 Joachim Eastwood * * UNSUPPORTED hardware features: * - 8-bit mode with different scales * - INT1/INT2 interrupts * - Offset calibration * - Events */ #include #include #include #include #include #include #include #include #include #include "mma7455.h" #define MMA7455_REG_XOUTL 0x00 #define MMA7455_REG_XOUTH 0x01 #define MMA7455_REG_YOUTL 0x02 #define MMA7455_REG_YOUTH 0x03 #define MMA7455_REG_ZOUTL 0x04 #define MMA7455_REG_ZOUTH 0x05 #define MMA7455_REG_STATUS 0x09 #define MMA7455_STATUS_DRDY BIT(0) #define MMA7455_REG_WHOAMI 0x0f #define MMA7455_WHOAMI_ID 0x55 #define MMA7455_REG_MCTL 0x16 #define MMA7455_MCTL_MODE_STANDBY 0x00 #define MMA7455_MCTL_MODE_MEASURE 0x01 #define MMA7455_REG_CTL1 0x18 #define MMA7455_CTL1_DFBW_MASK BIT(7) #define MMA7455_CTL1_DFBW_125HZ BIT(7) #define MMA7455_CTL1_DFBW_62_5HZ 0 #define MMA7455_REG_TW 0x1e /* * When MMA7455 is used in 10-bit it has a fullscale of -8g * corresponding to raw value -512. The userspace interface * uses m/s^2 and we declare micro units. * So scale factor is given by: * g * 8 * 1e6 / 512 = 153228.90625, with g = 9.80665 */ #define MMA7455_10BIT_SCALE 153229 struct mma7455_data { struct regmap *regmap; }; static int mma7455_drdy(struct mma7455_data *mma7455) { struct device *dev = regmap_get_device(mma7455->regmap); unsigned int reg; int tries = 3; int ret; while (tries-- > 0) { ret = regmap_read(mma7455->regmap, MMA7455_REG_STATUS, ®); if (ret) return ret; if (reg & MMA7455_STATUS_DRDY) return 0; msleep(20); } dev_warn(dev, "data not ready\n"); return -EIO; } static irqreturn_t mma7455_trigger_handler(int irq, void *p) { struct iio_poll_func *pf = p; struct iio_dev *indio_dev = pf->indio_dev; struct mma7455_data *mma7455 = iio_priv(indio_dev); u8 buf[16]; /* 3 x 16-bit channels + padding + ts */ int ret; ret = mma7455_drdy(mma7455); if (ret) goto done; ret = regmap_bulk_read(mma7455->regmap, MMA7455_REG_XOUTL, buf, sizeof(__le16) * 3); if (ret) goto done; iio_push_to_buffers_with_timestamp(indio_dev, buf, iio_get_time_ns(indio_dev)); done: iio_trigger_notify_done(indio_dev->trig); return IRQ_HANDLED; } static int mma7455_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val, int *val2, long mask) { struct mma7455_data *mma7455 = iio_priv(indio_dev); unsigned int reg; __le16 data; int ret; switch (mask) { case IIO_CHAN_INFO_RAW: if (iio_buffer_enabled(indio_dev)) return -EBUSY; ret = mma7455_drdy(mma7455); if (ret) return ret; ret = regmap_bulk_read(mma7455->regmap, chan->address, &data, sizeof(data)); if (ret) return ret; *val = sign_extend32(le16_to_cpu(data), 9); return IIO_VAL_INT; case IIO_CHAN_INFO_SCALE: *val = 0; *val2 = MMA7455_10BIT_SCALE; return IIO_VAL_INT_PLUS_MICRO; case IIO_CHAN_INFO_SAMP_FREQ: ret = regmap_read(mma7455->regmap, MMA7455_REG_CTL1, ®); if (ret) return ret; if (reg & MMA7455_CTL1_DFBW_MASK) *val = 250; else *val = 125; return IIO_VAL_INT; } return -EINVAL; } static int mma7455_write_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int val, int val2, long mask) { struct mma7455_data *mma7455 = iio_priv(indio_dev); int i; switch (mask) { case IIO_CHAN_INFO_SAMP_FREQ: if (val == 250 && val2 == 0) i = MMA7455_CTL1_DFBW_125HZ; else if (val == 125 && val2 == 0) i = MMA7455_CTL1_DFBW_62_5HZ; else return -EINVAL; return regmap_update_bits(mma7455->regmap, MMA7455_REG_CTL1, MMA7455_CTL1_DFBW_MASK, i); case IIO_CHAN_INFO_SCALE: /* In 10-bit mode there is only one scale available */ if (val == 0 && val2 == MMA7455_10BIT_SCALE) return 0; break; } return -EINVAL; } static IIO_CONST_ATTR(sampling_frequency_available, "125 250"); static struct attribute *mma7455_attributes[] = { &iio_const_attr_sampling_frequency_available.dev_attr.attr, NULL }; static const struct attribute_group mma7455_group = { .attrs = mma7455_attributes, }; static const struct iio_info mma7455_info = { .attrs = &mma7455_group, .read_raw = mma7455_read_raw, .write_raw = mma7455_write_raw, }; #define MMA7455_CHANNEL(axis, idx) { \ .type = IIO_ACCEL, \ .modified = 1, \ .address = MMA7455_REG_##axis##OUTL,\ .channel2 = IIO_MOD_##axis, \ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ) | \ BIT(IIO_CHAN_INFO_SCALE), \ .scan_index = idx, \ .scan_type = { \ .sign = 's', \ .realbits = 10, \ .storagebits = 16, \ .endianness = IIO_LE, \ }, \ } static const struct iio_chan_spec mma7455_channels[] = { MMA7455_CHANNEL(X, 0), MMA7455_CHANNEL(Y, 1), MMA7455_CHANNEL(Z, 2), IIO_CHAN_SOFT_TIMESTAMP(3), }; static const unsigned long mma7455_scan_masks[] = {0x7, 0}; const struct regmap_config mma7455_core_regmap = { .reg_bits = 8, .val_bits = 8, .max_register = MMA7455_REG_TW, }; EXPORT_SYMBOL_GPL(mma7455_core_regmap); int mma7455_core_probe(struct device *dev, struct regmap *regmap, const char *name) { struct mma7455_data *mma7455; struct iio_dev *indio_dev; unsigned int reg; int ret; ret = regmap_read(regmap, MMA7455_REG_WHOAMI, ®); if (ret) { dev_err(dev, "unable to read reg\n"); return ret; } if (reg != MMA7455_WHOAMI_ID) { dev_err(dev, "device id mismatch\n"); return -ENODEV; } indio_dev = devm_iio_device_alloc(dev, sizeof(*mma7455)); if (!indio_dev) return -ENOMEM; dev_set_drvdata(dev, indio_dev); mma7455 = iio_priv(indio_dev); mma7455->regmap = regmap; indio_dev->info = &mma7455_info; indio_dev->name = name; indio_dev->dev.parent = dev; indio_dev->modes = INDIO_DIRECT_MODE; indio_dev->channels = mma7455_channels; indio_dev->num_channels = ARRAY_SIZE(mma7455_channels); indio_dev->available_scan_masks = mma7455_scan_masks; regmap_write(mma7455->regmap, MMA7455_REG_MCTL, MMA7455_MCTL_MODE_MEASURE); ret = iio_triggered_buffer_setup(indio_dev, NULL, mma7455_trigger_handler, NULL); if (ret) { dev_err(dev, "unable to setup triggered buffer\n"); return ret; } ret = iio_device_register(indio_dev); if (ret) { dev_err(dev, "unable to register device\n"); iio_triggered_buffer_cleanup(indio_dev); return ret; } return 0; } EXPORT_SYMBOL_GPL(mma7455_core_probe); int mma7455_core_remove(struct device *dev) { struct iio_dev *indio_dev = dev_get_drvdata(dev); struct mma7455_data *mma7455 = iio_priv(indio_dev); iio_device_unregister(indio_dev); iio_triggered_buffer_cleanup(indio_dev); regmap_write(mma7455->regmap, MMA7455_REG_MCTL, MMA7455_MCTL_MODE_STANDBY); return 0; } EXPORT_SYMBOL_GPL(mma7455_core_remove); MODULE_AUTHOR("Joachim Eastwood "); MODULE_DESCRIPTION("Freescale MMA7455L core accelerometer driver"); MODULE_LICENSE("GPL v2");