// SPDX-License-Identifier: GPL-2.0 /* * PNI RM3100 3-axis geomagnetic sensor driver core. * * Copyright (C) 2018 Song Qiang * * User Manual available at * * * TODO: event generation, pm. */ #include #include #include #include #include #include #include #include #include #include #include #include "rm3100.h" /* Cycle Count Registers. */ #define RM3100_REG_CC_X 0x05 #define RM3100_REG_CC_Y 0x07 #define RM3100_REG_CC_Z 0x09 /* Poll Measurement Mode register. */ #define RM3100_REG_POLL 0x00 #define RM3100_POLL_X BIT(4) #define RM3100_POLL_Y BIT(5) #define RM3100_POLL_Z BIT(6) /* Continuous Measurement Mode register. */ #define RM3100_REG_CMM 0x01 #define RM3100_CMM_START BIT(0) #define RM3100_CMM_X BIT(4) #define RM3100_CMM_Y BIT(5) #define RM3100_CMM_Z BIT(6) /* TiMe Rate Configuration register. */ #define RM3100_REG_TMRC 0x0B #define RM3100_TMRC_OFFSET 0x92 /* Result Status register. */ #define RM3100_REG_STATUS 0x34 #define RM3100_STATUS_DRDY BIT(7) /* Measurement result registers. */ #define RM3100_REG_MX2 0x24 #define RM3100_REG_MY2 0x27 #define RM3100_REG_MZ2 0x2a #define RM3100_W_REG_START RM3100_REG_POLL #define RM3100_W_REG_END RM3100_REG_TMRC #define RM3100_R_REG_START RM3100_REG_POLL #define RM3100_R_REG_END RM3100_REG_STATUS #define RM3100_V_REG_START RM3100_REG_POLL #define RM3100_V_REG_END RM3100_REG_STATUS /* * This is computed by hand, is the sum of channel storage bits and padding * bits, which is 4+4+4+12=24 in here. */ #define RM3100_SCAN_BYTES 24 #define RM3100_CMM_AXIS_SHIFT 4 struct rm3100_data { struct regmap *regmap; struct completion measuring_done; bool use_interrupt; int conversion_time; int scale; /* Ensure naturally aligned timestamp */ u8 buffer[RM3100_SCAN_BYTES] __aligned(8); struct iio_trigger *drdy_trig; /* * This lock is for protecting the consistency of series of i2c * operations, that is, to make sure a measurement process will * not be interrupted by a set frequency operation, which should * be taken where a series of i2c operation starts, released where * the operation ends. */ struct mutex lock; }; static const struct regmap_range rm3100_readable_ranges[] = { regmap_reg_range(RM3100_R_REG_START, RM3100_R_REG_END), }; const struct regmap_access_table rm3100_readable_table = { .yes_ranges = rm3100_readable_ranges, .n_yes_ranges = ARRAY_SIZE(rm3100_readable_ranges), }; EXPORT_SYMBOL_GPL(rm3100_readable_table); static const struct regmap_range rm3100_writable_ranges[] = { regmap_reg_range(RM3100_W_REG_START, RM3100_W_REG_END), }; const struct regmap_access_table rm3100_writable_table = { .yes_ranges = rm3100_writable_ranges, .n_yes_ranges = ARRAY_SIZE(rm3100_writable_ranges), }; EXPORT_SYMBOL_GPL(rm3100_writable_table); static const struct regmap_range rm3100_volatile_ranges[] = { regmap_reg_range(RM3100_V_REG_START, RM3100_V_REG_END), }; const struct regmap_access_table rm3100_volatile_table = { .yes_ranges = rm3100_volatile_ranges, .n_yes_ranges = ARRAY_SIZE(rm3100_volatile_ranges), }; EXPORT_SYMBOL_GPL(rm3100_volatile_table); static irqreturn_t rm3100_thread_fn(int irq, void *d) { struct iio_dev *indio_dev = d; struct rm3100_data *data = iio_priv(indio_dev); /* * Write operation to any register or read operation * to first byte of results will clear the interrupt. */ regmap_write(data->regmap, RM3100_REG_POLL, 0); return IRQ_HANDLED; } static irqreturn_t rm3100_irq_handler(int irq, void *d) { struct iio_dev *indio_dev = d; struct rm3100_data *data = iio_priv(indio_dev); switch (indio_dev->currentmode) { case INDIO_DIRECT_MODE: complete(&data->measuring_done); break; case INDIO_BUFFER_TRIGGERED: iio_trigger_poll(data->drdy_trig); break; default: dev_err(indio_dev->dev.parent, "device mode out of control, current mode: %d", indio_dev->currentmode); } return IRQ_WAKE_THREAD; } static int rm3100_wait_measurement(struct rm3100_data *data) { struct regmap *regmap = data->regmap; unsigned int val; int tries = 20; int ret; /* * A read cycle of 400kbits i2c bus is about 20us, plus the time * used for scheduling, a read cycle of fast mode of this device * can reach 1.7ms, it may be possible for data to arrive just * after we check the RM3100_REG_STATUS. In this case, irq_handler is * called before measuring_done is reinitialized, it will wait * forever for data that has already been ready. * Reinitialize measuring_done before looking up makes sure we * will always capture interrupt no matter when it happens. */ if (data->use_interrupt) reinit_completion(&data->measuring_done); ret = regmap_read(regmap, RM3100_REG_STATUS, &val); if (ret < 0) return ret; if ((val & RM3100_STATUS_DRDY) != RM3100_STATUS_DRDY) { if (data->use_interrupt) { ret = wait_for_completion_timeout(&data->measuring_done, msecs_to_jiffies(data->conversion_time)); if (!ret) return -ETIMEDOUT; } else { do { usleep_range(1000, 5000); ret = regmap_read(regmap, RM3100_REG_STATUS, &val); if (ret < 0) return ret; if (val & RM3100_STATUS_DRDY) break; } while (--tries); if (!tries) return -ETIMEDOUT; } } return 0; } static int rm3100_read_mag(struct rm3100_data *data, int idx, int *val) { struct regmap *regmap = data->regmap; u8 buffer[3]; int ret; mutex_lock(&data->lock); ret = regmap_write(regmap, RM3100_REG_POLL, BIT(4 + idx)); if (ret < 0) goto unlock_return; ret = rm3100_wait_measurement(data); if (ret < 0) goto unlock_return; ret = regmap_bulk_read(regmap, RM3100_REG_MX2 + 3 * idx, buffer, 3); if (ret < 0) goto unlock_return; mutex_unlock(&data->lock); *val = sign_extend32(get_unaligned_be24(&buffer[0]), 23); return IIO_VAL_INT; unlock_return: mutex_unlock(&data->lock); return ret; } #define RM3100_CHANNEL(axis, idx) \ { \ .type = IIO_MAGN, \ .modified = 1, \ .channel2 = IIO_MOD_##axis, \ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \ BIT(IIO_CHAN_INFO_SAMP_FREQ), \ .scan_index = idx, \ .scan_type = { \ .sign = 's', \ .realbits = 24, \ .storagebits = 32, \ .shift = 8, \ .endianness = IIO_BE, \ }, \ } static const struct iio_chan_spec rm3100_channels[] = { RM3100_CHANNEL(X, 0), RM3100_CHANNEL(Y, 1), RM3100_CHANNEL(Z, 2), IIO_CHAN_SOFT_TIMESTAMP(3), }; static IIO_CONST_ATTR_SAMP_FREQ_AVAIL( "600 300 150 75 37 18 9 4.5 2.3 1.2 0.6 0.3 0.015 0.075" ); static struct attribute *rm3100_attributes[] = { &iio_const_attr_sampling_frequency_available.dev_attr.attr, NULL, }; static const struct attribute_group rm3100_attribute_group = { .attrs = rm3100_attributes, }; #define RM3100_SAMP_NUM 14 /* * Frequency : rm3100_samp_rates[][0].rm3100_samp_rates[][1]Hz. * Time between reading: rm3100_sam_rates[][2]ms. * The first one is actually 1.7ms. */ static const int rm3100_samp_rates[RM3100_SAMP_NUM][3] = { {600, 0, 2}, {300, 0, 3}, {150, 0, 7}, {75, 0, 13}, {37, 0, 27}, {18, 0, 55}, {9, 0, 110}, {4, 500000, 220}, {2, 300000, 440}, {1, 200000, 800}, {0, 600000, 1600}, {0, 300000, 3300}, {0, 15000, 6700}, {0, 75000, 13000} }; static int rm3100_get_samp_freq(struct rm3100_data *data, int *val, int *val2) { unsigned int tmp; int ret; mutex_lock(&data->lock); ret = regmap_read(data->regmap, RM3100_REG_TMRC, &tmp); mutex_unlock(&data->lock); if (ret < 0) return ret; *val = rm3100_samp_rates[tmp - RM3100_TMRC_OFFSET][0]; *val2 = rm3100_samp_rates[tmp - RM3100_TMRC_OFFSET][1]; return IIO_VAL_INT_PLUS_MICRO; } static int rm3100_set_cycle_count(struct rm3100_data *data, int val) { int ret; u8 i; for (i = 0; i < 3; i++) { ret = regmap_write(data->regmap, RM3100_REG_CC_X + 2 * i, val); if (ret < 0) return ret; } /* * The scale of this sensor depends on the cycle count value, these * three values are corresponding to the cycle count value 50, 100, * 200. scale = output / gain * 10^4. */ switch (val) { case 50: data->scale = 500; break; case 100: data->scale = 263; break; /* * case 200: * This function will never be called by users' code, so here we * assume that it will never get a wrong parameter. */ default: data->scale = 133; } return 0; } static int rm3100_set_samp_freq(struct iio_dev *indio_dev, int val, int val2) { struct rm3100_data *data = iio_priv(indio_dev); struct regmap *regmap = data->regmap; unsigned int cycle_count; int ret; int i; mutex_lock(&data->lock); /* All cycle count registers use the same value. */ ret = regmap_read(regmap, RM3100_REG_CC_X, &cycle_count); if (ret < 0) goto unlock_return; for (i = 0; i < RM3100_SAMP_NUM; i++) { if (val == rm3100_samp_rates[i][0] && val2 == rm3100_samp_rates[i][1]) break; } if (i == RM3100_SAMP_NUM) { ret = -EINVAL; goto unlock_return; } ret = regmap_write(regmap, RM3100_REG_TMRC, i + RM3100_TMRC_OFFSET); if (ret < 0) goto unlock_return; /* Checking if cycle count registers need changing. */ if (val == 600 && cycle_count == 200) { ret = rm3100_set_cycle_count(data, 100); if (ret < 0) goto unlock_return; } else if (val != 600 && cycle_count == 100) { ret = rm3100_set_cycle_count(data, 200); if (ret < 0) goto unlock_return; } if (indio_dev->currentmode == INDIO_BUFFER_TRIGGERED) { /* Writing TMRC registers requires CMM reset. */ ret = regmap_write(regmap, RM3100_REG_CMM, 0); if (ret < 0) goto unlock_return; ret = regmap_write(data->regmap, RM3100_REG_CMM, (*indio_dev->active_scan_mask & 0x7) << RM3100_CMM_AXIS_SHIFT | RM3100_CMM_START); if (ret < 0) goto unlock_return; } mutex_unlock(&data->lock); data->conversion_time = rm3100_samp_rates[i][2] * 2; return 0; unlock_return: mutex_unlock(&data->lock); return ret; } static int rm3100_read_raw(struct iio_dev *indio_dev, const struct iio_chan_spec *chan, int *val, int *val2, long mask) { struct rm3100_data *data = iio_priv(indio_dev); int ret; switch (mask) { case IIO_CHAN_INFO_RAW: ret = iio_device_claim_direct_mode(indio_dev); if (ret < 0) return ret; ret = rm3100_read_mag(data, chan->scan_index, val); iio_device_release_direct_mode(indio_dev); return ret; case IIO_CHAN_INFO_SCALE: *val = 0; *val2 = data->scale; return IIO_VAL_INT_PLUS_MICRO; case IIO_CHAN_INFO_SAMP_FREQ: return rm3100_get_samp_freq(data, val, val2); default: return -EINVAL; } } static int rm3100_write_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int val, int val2, long mask) { switch (mask) { case IIO_CHAN_INFO_SAMP_FREQ: return rm3100_set_samp_freq(indio_dev, val, val2); default: return -EINVAL; } } static const struct iio_info rm3100_info = { .attrs = &rm3100_attribute_group, .read_raw = rm3100_read_raw, .write_raw = rm3100_write_raw, }; static int rm3100_buffer_preenable(struct iio_dev *indio_dev) { struct rm3100_data *data = iio_priv(indio_dev); /* Starting channels enabled. */ return regmap_write(data->regmap, RM3100_REG_CMM, (*indio_dev->active_scan_mask & 0x7) << RM3100_CMM_AXIS_SHIFT | RM3100_CMM_START); } static int rm3100_buffer_postdisable(struct iio_dev *indio_dev) { struct rm3100_data *data = iio_priv(indio_dev); return regmap_write(data->regmap, RM3100_REG_CMM, 0); } static const struct iio_buffer_setup_ops rm3100_buffer_ops = { .preenable = rm3100_buffer_preenable, .postdisable = rm3100_buffer_postdisable, }; static irqreturn_t rm3100_trigger_handler(int irq, void *p) { struct iio_poll_func *pf = p; struct iio_dev *indio_dev = pf->indio_dev; unsigned long scan_mask = *indio_dev->active_scan_mask; unsigned int mask_len = indio_dev->masklength; struct rm3100_data *data = iio_priv(indio_dev); struct regmap *regmap = data->regmap; int ret, i, bit; mutex_lock(&data->lock); switch (scan_mask) { case BIT(0) | BIT(1) | BIT(2): ret = regmap_bulk_read(regmap, RM3100_REG_MX2, data->buffer, 9); mutex_unlock(&data->lock); if (ret < 0) goto done; /* Convert XXXYYYZZZxxx to XXXxYYYxZZZx. x for paddings. */ for (i = 2; i > 0; i--) memmove(data->buffer + i * 4, data->buffer + i * 3, 3); break; case BIT(0) | BIT(1): ret = regmap_bulk_read(regmap, RM3100_REG_MX2, data->buffer, 6); mutex_unlock(&data->lock); if (ret < 0) goto done; memmove(data->buffer + 4, data->buffer + 3, 3); break; case BIT(1) | BIT(2): ret = regmap_bulk_read(regmap, RM3100_REG_MY2, data->buffer, 6); mutex_unlock(&data->lock); if (ret < 0) goto done; memmove(data->buffer + 4, data->buffer + 3, 3); break; case BIT(0) | BIT(2): ret = regmap_bulk_read(regmap, RM3100_REG_MX2, data->buffer, 9); mutex_unlock(&data->lock); if (ret < 0) goto done; memmove(data->buffer + 4, data->buffer + 6, 3); break; default: for_each_set_bit(bit, &scan_mask, mask_len) { ret = regmap_bulk_read(regmap, RM3100_REG_MX2 + 3 * bit, data->buffer, 3); if (ret < 0) { mutex_unlock(&data->lock); goto done; } } mutex_unlock(&data->lock); } /* * Always using the same buffer so that we wouldn't need to set the * paddings to 0 in case of leaking any data. */ iio_push_to_buffers_with_timestamp(indio_dev, data->buffer, pf->timestamp); done: iio_trigger_notify_done(indio_dev->trig); return IRQ_HANDLED; } int rm3100_common_probe(struct device *dev, struct regmap *regmap, int irq) { struct iio_dev *indio_dev; struct rm3100_data *data; unsigned int tmp; int ret; indio_dev = devm_iio_device_alloc(dev, sizeof(*data)); if (!indio_dev) return -ENOMEM; data = iio_priv(indio_dev); data->regmap = regmap; mutex_init(&data->lock); indio_dev->name = "rm3100"; indio_dev->info = &rm3100_info; indio_dev->channels = rm3100_channels; indio_dev->num_channels = ARRAY_SIZE(rm3100_channels); indio_dev->modes = INDIO_DIRECT_MODE | INDIO_BUFFER_TRIGGERED; indio_dev->currentmode = INDIO_DIRECT_MODE; if (!irq) data->use_interrupt = false; else { data->use_interrupt = true; init_completion(&data->measuring_done); ret = devm_request_threaded_irq(dev, irq, rm3100_irq_handler, rm3100_thread_fn, IRQF_TRIGGER_HIGH | IRQF_ONESHOT, indio_dev->name, indio_dev); if (ret < 0) { dev_err(dev, "request irq line failed.\n"); return ret; } data->drdy_trig = devm_iio_trigger_alloc(dev, "%s-drdy%d", indio_dev->name, iio_device_id(indio_dev)); if (!data->drdy_trig) return -ENOMEM; ret = devm_iio_trigger_register(dev, data->drdy_trig); if (ret < 0) return ret; } ret = devm_iio_triggered_buffer_setup(dev, indio_dev, &iio_pollfunc_store_time, rm3100_trigger_handler, &rm3100_buffer_ops); if (ret < 0) return ret; ret = regmap_read(regmap, RM3100_REG_TMRC, &tmp); if (ret < 0) return ret; /* Initializing max wait time, which is double conversion time. */ data->conversion_time = rm3100_samp_rates[tmp - RM3100_TMRC_OFFSET][2] * 2; /* Cycle count values may not be what we want. */ if ((tmp - RM3100_TMRC_OFFSET) == 0) rm3100_set_cycle_count(data, 100); else rm3100_set_cycle_count(data, 200); return devm_iio_device_register(dev, indio_dev); } EXPORT_SYMBOL_GPL(rm3100_common_probe); MODULE_AUTHOR("Song Qiang "); MODULE_DESCRIPTION("PNI RM3100 3-axis magnetometer i2c driver"); MODULE_LICENSE("GPL v2");