diff options
Diffstat (limited to 'drivers/iio/accel/kionix-kx022a.c')
| -rw-r--r-- | drivers/iio/accel/kionix-kx022a.c | 1142 |
1 files changed, 1142 insertions, 0 deletions
diff --git a/drivers/iio/accel/kionix-kx022a.c b/drivers/iio/accel/kionix-kx022a.c new file mode 100644 index 000000000000..f866859855cd --- /dev/null +++ b/drivers/iio/accel/kionix-kx022a.c @@ -0,0 +1,1142 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2022 ROHM Semiconductors + * + * ROHM/KIONIX KX022A accelerometer driver + */ + +#include <linux/delay.h> +#include <linux/device.h> +#include <linux/interrupt.h> +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/mutex.h> +#include <linux/property.h> +#include <linux/regmap.h> +#include <linux/regulator/consumer.h> +#include <linux/slab.h> +#include <linux/string_helpers.h> +#include <linux/units.h> + +#include <linux/iio/iio.h> +#include <linux/iio/sysfs.h> +#include <linux/iio/trigger.h> +#include <linux/iio/trigger_consumer.h> +#include <linux/iio/triggered_buffer.h> + +#include "kionix-kx022a.h" + +/* + * The KX022A has FIFO which can store 43 samples of HiRes data from 2 + * channels. This equals to 43 (samples) * 3 (channels) * 2 (bytes/sample) to + * 258 bytes of sample data. The quirk to know is that the amount of bytes in + * the FIFO is advertised via 8 bit register (max value 255). The thing to note + * is that full 258 bytes of data is indicated using the max value 255. + */ +#define KX022A_FIFO_LENGTH 43 +#define KX022A_FIFO_FULL_VALUE 255 +#define KX022A_SOFT_RESET_WAIT_TIME_US (5 * USEC_PER_MSEC) +#define KX022A_SOFT_RESET_TOTAL_WAIT_TIME_US (500 * USEC_PER_MSEC) + +/* 3 axis, 2 bytes of data for each of the axis */ +#define KX022A_FIFO_SAMPLES_SIZE_BYTES 6 +#define KX022A_FIFO_MAX_BYTES \ + (KX022A_FIFO_LENGTH * KX022A_FIFO_SAMPLES_SIZE_BYTES) + +enum { + KX022A_STATE_SAMPLE, + KX022A_STATE_FIFO, +}; + +/* Regmap configs */ +static const struct regmap_range kx022a_volatile_ranges[] = { + { + .range_min = KX022A_REG_XHP_L, + .range_max = KX022A_REG_COTR, + }, { + .range_min = KX022A_REG_TSCP, + .range_max = KX022A_REG_INT_REL, + }, { + /* The reset bit will be cleared by sensor */ + .range_min = KX022A_REG_CNTL2, + .range_max = KX022A_REG_CNTL2, + }, { + .range_min = KX022A_REG_BUF_STATUS_1, + .range_max = KX022A_REG_BUF_READ, + }, +}; + +static const struct regmap_access_table kx022a_volatile_regs = { + .yes_ranges = &kx022a_volatile_ranges[0], + .n_yes_ranges = ARRAY_SIZE(kx022a_volatile_ranges), +}; + +static const struct regmap_range kx022a_precious_ranges[] = { + { + .range_min = KX022A_REG_INT_REL, + .range_max = KX022A_REG_INT_REL, + }, +}; + +static const struct regmap_access_table kx022a_precious_regs = { + .yes_ranges = &kx022a_precious_ranges[0], + .n_yes_ranges = ARRAY_SIZE(kx022a_precious_ranges), +}; + +/* + * The HW does not set WHO_AM_I reg as read-only but we don't want to write it + * so we still include it in the read-only ranges. + */ +static const struct regmap_range kx022a_read_only_ranges[] = { + { + .range_min = KX022A_REG_XHP_L, + .range_max = KX022A_REG_INT_REL, + }, { + .range_min = KX022A_REG_BUF_STATUS_1, + .range_max = KX022A_REG_BUF_STATUS_2, + }, { + .range_min = KX022A_REG_BUF_READ, + .range_max = KX022A_REG_BUF_READ, + }, +}; + +static const struct regmap_access_table kx022a_ro_regs = { + .no_ranges = &kx022a_read_only_ranges[0], + .n_no_ranges = ARRAY_SIZE(kx022a_read_only_ranges), +}; + +static const struct regmap_range kx022a_write_only_ranges[] = { + { + .range_min = KX022A_REG_BTS_WUF_TH, + .range_max = KX022A_REG_BTS_WUF_TH, + }, { + .range_min = KX022A_REG_MAN_WAKE, + .range_max = KX022A_REG_MAN_WAKE, + }, { + .range_min = KX022A_REG_SELF_TEST, + .range_max = KX022A_REG_SELF_TEST, + }, { + .range_min = KX022A_REG_BUF_CLEAR, + .range_max = KX022A_REG_BUF_CLEAR, + }, +}; + +static const struct regmap_access_table kx022a_wo_regs = { + .no_ranges = &kx022a_write_only_ranges[0], + .n_no_ranges = ARRAY_SIZE(kx022a_write_only_ranges), +}; + +static const struct regmap_range kx022a_noinc_read_ranges[] = { + { + .range_min = KX022A_REG_BUF_READ, + .range_max = KX022A_REG_BUF_READ, + }, +}; + +static const struct regmap_access_table kx022a_nir_regs = { + .yes_ranges = &kx022a_noinc_read_ranges[0], + .n_yes_ranges = ARRAY_SIZE(kx022a_noinc_read_ranges), +}; + +const struct regmap_config kx022a_regmap = { + .reg_bits = 8, + .val_bits = 8, + .volatile_table = &kx022a_volatile_regs, + .rd_table = &kx022a_wo_regs, + .wr_table = &kx022a_ro_regs, + .rd_noinc_table = &kx022a_nir_regs, + .precious_table = &kx022a_precious_regs, + .max_register = KX022A_MAX_REGISTER, + .cache_type = REGCACHE_RBTREE, +}; +EXPORT_SYMBOL_NS_GPL(kx022a_regmap, IIO_KX022A); + +struct kx022a_data { + struct regmap *regmap; + struct iio_trigger *trig; + struct device *dev; + struct iio_mount_matrix orientation; + int64_t timestamp, old_timestamp; + + int irq; + int inc_reg; + int ien_reg; + + unsigned int g_range; + unsigned int state; + unsigned int odr_ns; + + bool trigger_enabled; + /* + * Prevent toggling the sensor stby/active state (PC1 bit) in the + * middle of a configuration, or when the fifo is enabled. Also, + * protect the data stored/retrieved from this structure from + * concurrent accesses. + */ + struct mutex mutex; + u8 watermark; + + /* 3 x 16bit accel data + timestamp */ + __le16 buffer[8] __aligned(IIO_DMA_MINALIGN); + struct { + __le16 channels[3]; + s64 ts __aligned(8); + } scan; +}; + +static const struct iio_mount_matrix * +kx022a_get_mount_matrix(const struct iio_dev *idev, + const struct iio_chan_spec *chan) +{ + struct kx022a_data *data = iio_priv(idev); + + return &data->orientation; +} + +enum { + AXIS_X, + AXIS_Y, + AXIS_Z, + AXIS_MAX +}; + +static const unsigned long kx022a_scan_masks[] = { + BIT(AXIS_X) | BIT(AXIS_Y) | BIT(AXIS_Z), 0 +}; + +static const struct iio_chan_spec_ext_info kx022a_ext_info[] = { + IIO_MOUNT_MATRIX(IIO_SHARED_BY_TYPE, kx022a_get_mount_matrix), + { } +}; + +#define KX022A_ACCEL_CHAN(axis, index) \ +{ \ + .type = IIO_ACCEL, \ + .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), \ + .info_mask_shared_by_type_available = \ + BIT(IIO_CHAN_INFO_SCALE) | \ + BIT(IIO_CHAN_INFO_SAMP_FREQ), \ + .ext_info = kx022a_ext_info, \ + .address = KX022A_REG_##axis##OUT_L, \ + .scan_index = index, \ + .scan_type = { \ + .sign = 's', \ + .realbits = 16, \ + .storagebits = 16, \ + .endianness = IIO_LE, \ + }, \ +} + +static const struct iio_chan_spec kx022a_channels[] = { + KX022A_ACCEL_CHAN(X, 0), + KX022A_ACCEL_CHAN(Y, 1), + KX022A_ACCEL_CHAN(Z, 2), + IIO_CHAN_SOFT_TIMESTAMP(3), +}; + +/* + * The sensor HW can support ODR up to 1600 Hz, which is beyond what most of the + * Linux CPUs can handle without dropping samples. Also, the low power mode is + * not available for higher sample rates. Thus, the driver only supports 200 Hz + * and slower ODRs. The slowest is 0.78 Hz. + */ +static const int kx022a_accel_samp_freq_table[][2] = { + { 0, 780000 }, + { 1, 563000 }, + { 3, 125000 }, + { 6, 250000 }, + { 12, 500000 }, + { 25, 0 }, + { 50, 0 }, + { 100, 0 }, + { 200, 0 }, +}; + +static const unsigned int kx022a_odrs[] = { + 1282051282, + 639795266, + 320 * MEGA, + 160 * MEGA, + 80 * MEGA, + 40 * MEGA, + 20 * MEGA, + 10 * MEGA, + 5 * MEGA, +}; + +/* + * range is typically +-2G/4G/8G/16G, distributed over the amount of bits. + * The scale table can be calculated using + * (range / 2^bits) * g = (range / 2^bits) * 9.80665 m/s^2 + * => KX022A uses 16 bit (HiRes mode - assume the low 8 bits are zeroed + * in low-power mode(?) ) + * => +/-2G => 4 / 2^16 * 9,80665 * 10^6 (to scale to micro) + * => +/-2G - 598.550415 + * +/-4G - 1197.10083 + * +/-8G - 2394.20166 + * +/-16G - 4788.40332 + */ +static const int kx022a_scale_table[][2] = { + { 598, 550415 }, + { 1197, 100830 }, + { 2394, 201660 }, + { 4788, 403320 }, +}; + +static int kx022a_read_avail(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + const int **vals, int *type, int *length, + long mask) +{ + switch (mask) { + case IIO_CHAN_INFO_SAMP_FREQ: + *vals = (const int *)kx022a_accel_samp_freq_table; + *length = ARRAY_SIZE(kx022a_accel_samp_freq_table) * + ARRAY_SIZE(kx022a_accel_samp_freq_table[0]); + *type = IIO_VAL_INT_PLUS_MICRO; + return IIO_AVAIL_LIST; + case IIO_CHAN_INFO_SCALE: + *vals = (const int *)kx022a_scale_table; + *length = ARRAY_SIZE(kx022a_scale_table) * + ARRAY_SIZE(kx022a_scale_table[0]); + *type = IIO_VAL_INT_PLUS_MICRO; + return IIO_AVAIL_LIST; + default: + return -EINVAL; + } +} + +#define KX022A_DEFAULT_PERIOD_NS (20 * NSEC_PER_MSEC) + +static void kx022a_reg2freq(unsigned int val, int *val1, int *val2) +{ + *val1 = kx022a_accel_samp_freq_table[val & KX022A_MASK_ODR][0]; + *val2 = kx022a_accel_samp_freq_table[val & KX022A_MASK_ODR][1]; +} + +static void kx022a_reg2scale(unsigned int val, unsigned int *val1, + unsigned int *val2) +{ + val &= KX022A_MASK_GSEL; + val >>= KX022A_GSEL_SHIFT; + + *val1 = kx022a_scale_table[val][0]; + *val2 = kx022a_scale_table[val][1]; +} + +static int kx022a_turn_on_off_unlocked(struct kx022a_data *data, bool on) +{ + int ret; + + if (on) + ret = regmap_set_bits(data->regmap, KX022A_REG_CNTL, + KX022A_MASK_PC1); + else + ret = regmap_clear_bits(data->regmap, KX022A_REG_CNTL, + KX022A_MASK_PC1); + if (ret) + dev_err(data->dev, "Turn %s fail %d\n", str_on_off(on), ret); + + return ret; + +} + +static int kx022a_turn_off_lock(struct kx022a_data *data) +{ + int ret; + + mutex_lock(&data->mutex); + ret = kx022a_turn_on_off_unlocked(data, false); + if (ret) + mutex_unlock(&data->mutex); + + return ret; +} + +static int kx022a_turn_on_unlock(struct kx022a_data *data) +{ + int ret; + + ret = kx022a_turn_on_off_unlocked(data, true); + mutex_unlock(&data->mutex); + + return ret; +} + +static int kx022a_write_raw(struct iio_dev *idev, + struct iio_chan_spec const *chan, + int val, int val2, long mask) +{ + struct kx022a_data *data = iio_priv(idev); + int ret, n; + + /* + * We should not allow changing scale or frequency when FIFO is running + * as it will mess the timestamp/scale for samples existing in the + * buffer. If this turns out to be an issue we can later change logic + * to internally flush the fifo before reconfiguring so the samples in + * fifo keep matching the freq/scale settings. (Such setup could cause + * issues if users trust the watermark to be reached within known + * time-limit). + */ + ret = iio_device_claim_direct_mode(idev); + if (ret) + return ret; + + switch (mask) { + case IIO_CHAN_INFO_SAMP_FREQ: + n = ARRAY_SIZE(kx022a_accel_samp_freq_table); + + while (n--) + if (val == kx022a_accel_samp_freq_table[n][0] && + val2 == kx022a_accel_samp_freq_table[n][1]) + break; + if (n < 0) { + ret = -EINVAL; + goto unlock_out; + } + ret = kx022a_turn_off_lock(data); + if (ret) + break; + + ret = regmap_update_bits(data->regmap, + KX022A_REG_ODCNTL, + KX022A_MASK_ODR, n); + data->odr_ns = kx022a_odrs[n]; + kx022a_turn_on_unlock(data); + break; + case IIO_CHAN_INFO_SCALE: + n = ARRAY_SIZE(kx022a_scale_table); + + while (n-- > 0) + if (val == kx022a_scale_table[n][0] && + val2 == kx022a_scale_table[n][1]) + break; + if (n < 0) { + ret = -EINVAL; + goto unlock_out; + } + + ret = kx022a_turn_off_lock(data); + if (ret) + break; + + ret = regmap_update_bits(data->regmap, KX022A_REG_CNTL, + KX022A_MASK_GSEL, + n << KX022A_GSEL_SHIFT); + kx022a_turn_on_unlock(data); + break; + default: + ret = -EINVAL; + break; + } + +unlock_out: + iio_device_release_direct_mode(idev); + + return ret; +} + +static int kx022a_fifo_set_wmi(struct kx022a_data *data) +{ + u8 threshold; + + threshold = data->watermark; + + return regmap_update_bits(data->regmap, KX022A_REG_BUF_CNTL1, + KX022A_MASK_WM_TH, threshold); +} + +static int kx022a_get_axis(struct kx022a_data *data, + struct iio_chan_spec const *chan, + int *val) +{ + int ret; + + ret = regmap_bulk_read(data->regmap, chan->address, &data->buffer[0], + sizeof(__le16)); + if (ret) + return ret; + + *val = le16_to_cpu(data->buffer[0]); + + return IIO_VAL_INT; +} + +static int kx022a_read_raw(struct iio_dev *idev, + struct iio_chan_spec const *chan, + int *val, int *val2, long mask) +{ + struct kx022a_data *data = iio_priv(idev); + unsigned int regval; + int ret; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + ret = iio_device_claim_direct_mode(idev); + if (ret) + return ret; + + mutex_lock(&data->mutex); + ret = kx022a_get_axis(data, chan, val); + mutex_unlock(&data->mutex); + + iio_device_release_direct_mode(idev); + + return ret; + + case IIO_CHAN_INFO_SAMP_FREQ: + ret = regmap_read(data->regmap, KX022A_REG_ODCNTL, ®val); + if (ret) + return ret; + + if ((regval & KX022A_MASK_ODR) > + ARRAY_SIZE(kx022a_accel_samp_freq_table)) { + dev_err(data->dev, "Invalid ODR\n"); + return -EINVAL; + } + + kx022a_reg2freq(regval, val, val2); + + return IIO_VAL_INT_PLUS_MICRO; + + case IIO_CHAN_INFO_SCALE: + ret = regmap_read(data->regmap, KX022A_REG_CNTL, ®val); + if (ret < 0) + return ret; + + kx022a_reg2scale(regval, val, val2); + + return IIO_VAL_INT_PLUS_MICRO; + } + + return -EINVAL; +}; + +static int kx022a_validate_trigger(struct iio_dev *idev, + struct iio_trigger *trig) +{ + struct kx022a_data *data = iio_priv(idev); + + if (data->trig != trig) + return -EINVAL; + + return 0; +} + +static int kx022a_set_watermark(struct iio_dev *idev, unsigned int val) +{ + struct kx022a_data *data = iio_priv(idev); + + if (val > KX022A_FIFO_LENGTH) + val = KX022A_FIFO_LENGTH; + + mutex_lock(&data->mutex); + data->watermark = val; + mutex_unlock(&data->mutex); + + return 0; +} + +static ssize_t hwfifo_enabled_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct iio_dev *idev = dev_to_iio_dev(dev); + struct kx022a_data *data = iio_priv(idev); + bool state; + + mutex_lock(&data->mutex); + state = data->state; + mutex_unlock(&data->mutex); + + return sysfs_emit(buf, "%d\n", state); +} + +static ssize_t hwfifo_watermark_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct iio_dev *idev = dev_to_iio_dev(dev); + struct kx022a_data *data = iio_priv(idev); + int wm; + + mutex_lock(&data->mutex); + wm = data->watermark; + mutex_unlock(&data->mutex); + + return sysfs_emit(buf, "%d\n", wm); +} + +static IIO_DEVICE_ATTR_RO(hwfifo_enabled, 0); +static IIO_DEVICE_ATTR_RO(hwfifo_watermark, 0); + +static const struct iio_dev_attr *kx022a_fifo_attributes[] = { + &iio_dev_attr_hwfifo_watermark, + &iio_dev_attr_hwfifo_enabled, + NULL +}; + +static int kx022a_drop_fifo_contents(struct kx022a_data *data) +{ + /* + * We must clear the old time-stamp to avoid computing the timestamps + * based on samples acquired when buffer was last enabled. + * + * We don't need to protect the timestamp as long as we are only + * called from fifo-disable where we can guarantee the sensor is not + * triggering interrupts and where the mutex is locked to prevent the + * user-space access. + */ + data->timestamp = 0; + + return regmap_write(data->regmap, KX022A_REG_BUF_CLEAR, 0x0); +} + +static int __kx022a_fifo_flush(struct iio_dev *idev, unsigned int samples, + bool irq) +{ + struct kx022a_data *data = iio_priv(idev); + struct device *dev = regmap_get_device(data->regmap); + __le16 buffer[KX022A_FIFO_LENGTH * 3]; + uint64_t sample_period; + int count, fifo_bytes; + bool renable = false; + int64_t tstamp; + int ret, i; + + ret = regmap_read(data->regmap, KX022A_REG_BUF_STATUS_1, &fifo_bytes); + if (ret) { + dev_err(dev, "Error reading buffer status\n"); + return ret; + } + + /* Let's not overflow if we for some reason get bogus value from i2c */ + if (fifo_bytes == KX022A_FIFO_FULL_VALUE) + fifo_bytes = KX022A_FIFO_MAX_BYTES; + + if (fifo_bytes % KX022A_FIFO_SAMPLES_SIZE_BYTES) + dev_warn(data->dev, "Bad FIFO alignment. Data may be corrupt\n"); + + count = fifo_bytes / KX022A_FIFO_SAMPLES_SIZE_BYTES; + if (!count) + return 0; + + /* + * If we are being called from IRQ handler we know the stored timestamp + * is fairly accurate for the last stored sample. Otherwise, if we are + * called as a result of a read operation from userspace and hence + * before the watermark interrupt was triggered, take a timestamp + * now. We can fall anywhere in between two samples so the error in this + * case is at most one sample period. + */ + if (!irq) { + /* + * We need to have the IRQ disabled or we risk of messing-up + * the timestamps. If we are ran from IRQ, then the + * IRQF_ONESHOT has us covered - but if we are ran by the + * user-space read we need to disable the IRQ to be on a safe + * side. We do this usng synchronous disable so that if the + * IRQ thread is being ran on other CPU we wait for it to be + * finished. + */ + disable_irq(data->irq); + renable = true; + + data->old_timestamp = data->timestamp; + data->timestamp = iio_get_time_ns(idev); + } + + /* + * Approximate timestamps for each of the sample based on the sampling + * frequency, timestamp for last sample and number of samples. + * + * We'd better not use the current bandwidth settings to compute the + * sample period. The real sample rate varies with the device and + * small variation adds when we store a large number of samples. + * + * To avoid this issue we compute the actual sample period ourselves + * based on the timestamp delta between the last two flush operations. + */ + if (data->old_timestamp) { + sample_period = data->timestamp - data->old_timestamp; + do_div(sample_period, count); + } else { + sample_period = data->odr_ns; + } + tstamp = data->timestamp - (count - 1) * sample_period; + + if (samples && count > samples) { + /* + * Here we leave some old samples to the buffer. We need to + * adjust the timestamp to match the first sample in the buffer + * or we will miscalculate the sample_period at next round. + */ + data->timestamp -= (count - samples) * sample_period; + count = samples; + } + + fifo_bytes = count * KX022A_FIFO_SAMPLES_SIZE_BYTES; + ret = regmap_noinc_read(data->regmap, KX022A_REG_BUF_READ, + &buffer[0], fifo_bytes); + if (ret) + goto renable_out; + + for (i = 0; i < count; i++) { + __le16 *sam = &buffer[i * 3]; + __le16 *chs; + int bit; + + chs = &data->scan.channels[0]; + for_each_set_bit(bit, idev->active_scan_mask, AXIS_MAX) + chs[bit] = sam[bit]; + + iio_push_to_buffers_with_timestamp(idev, &data->scan, tstamp); + + tstamp += sample_period; + } + + ret = count; + +renable_out: + if (renable) + enable_irq(data->irq); + + return ret; +} + +static int kx022a_fifo_flush(struct iio_dev *idev, unsigned int samples) +{ + struct kx022a_data *data = iio_priv(idev); + int ret; + + mutex_lock(&data->mutex); + ret = __kx022a_fifo_flush(idev, samples, false); + mutex_unlock(&data->mutex); + + return ret; +} + +static const struct iio_info kx022a_info = { + .read_raw = &kx022a_read_raw, + .write_raw = &kx022a_write_raw, + .read_avail = &kx022a_read_avail, + + .validate_trigger = kx022a_validate_trigger, + .hwfifo_set_watermark = kx022a_set_watermark, + .hwfifo_flush_to_buffer = kx022a_fifo_flush, +}; + +static int kx022a_set_drdy_irq(struct kx022a_data *data, bool en) +{ + if (en) + return regmap_set_bits(data->regmap, KX022A_REG_CNTL, + KX022A_MASK_DRDY); + + return regmap_clear_bits(data->regmap, KX022A_REG_CNTL, + KX022A_MASK_DRDY); +} + +static int kx022a_prepare_irq_pin(struct kx022a_data *data) +{ + /* Enable IRQ1 pin. Set polarity to active low */ + int mask = KX022A_MASK_IEN | KX022A_MASK_IPOL | + KX022A_MASK_ITYP; + int val = KX022A_MASK_IEN | KX022A_IPOL_LOW | + KX022A_ITYP_LEVEL; + int ret; + + ret = regmap_update_bits(data->regmap, data->inc_reg, mask, val); + if (ret) + return ret; + + /* We enable WMI to IRQ pin only at buffer_enable */ + mask = KX022A_MASK_INS2_DRDY; + + return regmap_set_bits(data->regmap, data->ien_reg, mask); +} + +static int kx022a_fifo_disable(struct kx022a_data *data) +{ + int ret = 0; + + ret = kx022a_turn_off_lock(data); + if (ret) + return ret; + + ret = regmap_clear_bits(data->regmap, data->ien_reg, KX022A_MASK_WMI); + if (ret) + goto unlock_out; + + ret = regmap_clear_bits(data->regmap, KX022A_REG_BUF_CNTL2, + KX022A_MASK_BUF_EN); + if (ret) + goto unlock_out; + + data->state &= ~KX022A_STATE_FIFO; + + kx022a_drop_fifo_contents(data); + + return kx022a_turn_on_unlock(data); + +unlock_out: + mutex_unlock(&data->mutex); + + return ret; +} + +static int kx022a_buffer_predisable(struct iio_dev *idev) +{ + struct kx022a_data *data = iio_priv(idev); + + if (iio_device_get_current_mode(idev) == INDIO_BUFFER_TRIGGERED) + return 0; + + return kx022a_fifo_disable(data); +} + +static int kx022a_fifo_enable(struct kx022a_data *data) +{ + int ret; + + ret = kx022a_turn_off_lock(data); + if (ret) + return ret; + + /* Update watermark to HW */ + ret = kx022a_fifo_set_wmi(data); + if (ret) + goto unlock_out; + + /* Enable buffer */ + ret = regmap_set_bits(data->regmap, KX022A_REG_BUF_CNTL2, + KX022A_MASK_BUF_EN); + if (ret) + goto unlock_out; + + data->state |= KX022A_STATE_FIFO; + ret = regmap_set_bits(data->regmap, data->ien_reg, + KX022A_MASK_WMI); + if (ret) + goto unlock_out; + + return kx022a_turn_on_unlock(data); + +unlock_out: + mutex_unlock(&data->mutex); + + return ret; +} + +static int kx022a_buffer_postenable(struct iio_dev *idev) +{ + struct kx022a_data *data = iio_priv(idev); + + /* + * If we use data-ready trigger, then the IRQ masks should be handled by + * trigger enable and the hardware buffer is not used but we just update + * results to the IIO fifo when data-ready triggers. + */ + if (iio_device_get_current_mode(idev) == INDIO_BUFFER_TRIGGERED) + return 0; + + return kx022a_fifo_enable(data); +} + +static const struct iio_buffer_setup_ops kx022a_buffer_ops = { + .postenable = kx022a_buffer_postenable, + .predisable = kx022a_buffer_predisable, +}; + +static irqreturn_t kx022a_trigger_handler(int irq, void *p) +{ + struct iio_poll_func *pf = p; + struct iio_dev *idev = pf->indio_dev; + struct kx022a_data *data = iio_priv(idev); + int ret; + + ret = regmap_bulk_read(data->regmap, KX022A_REG_XOUT_L, data->buffer, + KX022A_FIFO_SAMPLES_SIZE_BYTES); + if (ret < 0) + goto err_read; + + iio_push_to_buffers_with_timestamp(idev, data->buffer, pf->timestamp); +err_read: + iio_trigger_notify_done(idev->trig); + + return IRQ_HANDLED; +} + +/* Get timestamps and wake the thread if we need to read data */ +static irqreturn_t kx022a_irq_handler(int irq, void *private) +{ + struct iio_dev *idev = private; + struct kx022a_data *data = iio_priv(idev); + + data->old_timestamp = data->timestamp; + data->timestamp = iio_get_time_ns(idev); + + if (data->state & KX022A_STATE_FIFO || data->trigger_enabled) + return IRQ_WAKE_THREAD; + + return IRQ_NONE; +} + +/* + * WMI and data-ready IRQs are acked when results are read. If we add + * TILT/WAKE or other IRQs - then we may need to implement the acking + * (which is racy). + */ +static irqreturn_t kx022a_irq_thread_handler(int irq, void *private) +{ + struct iio_dev *idev = private; + struct kx022a_data *data = iio_priv(idev); + irqreturn_t ret = IRQ_NONE; + + mutex_lock(&data->mutex); + + if (data->trigger_enabled) { + iio_trigger_poll_chained(data->trig); + ret = IRQ_HANDLED; + } + + if (data->state & KX022A_STATE_FIFO) { + int ok; + + ok = __kx022a_fifo_flush(idev, KX022A_FIFO_LENGTH, true); + if (ok > 0) + ret = IRQ_HANDLED; + } + + mutex_unlock(&data->mutex); + + return ret; +} + +static int kx022a_trigger_set_state(struct iio_trigger *trig, + bool state) +{ + struct kx022a_data *data = iio_trigger_get_drvdata(trig); + int ret = 0; + + mutex_lock(&data->mutex); + + if (data->trigger_enabled == state) + goto unlock_out; + + if (data->state & KX022A_STATE_FIFO) { + dev_warn(data->dev, "Can't set trigger when FIFO enabled\n"); + ret = -EBUSY; + goto unlock_out; + } + + ret = kx022a_turn_on_off_unlocked(data, false); + if (ret) + goto unlock_out; + + data->trigger_enabled = state; + ret = kx022a_set_drdy_irq(data, state); + if (ret) + goto unlock_out; + + ret = kx022a_turn_on_off_unlocked(data, true); + +unlock_out: + mutex_unlock(&data->mutex); + + return ret; +} + +static const struct iio_trigger_ops kx022a_trigger_ops = { + .set_trigger_state = kx022a_trigger_set_state, +}; + +static int kx022a_chip_init(struct kx022a_data *data) +{ + int ret, val; + + /* Reset the senor */ + ret = regmap_write(data->regmap, KX022A_REG_CNTL2, KX022A_MASK_SRST); + if (ret) + return ret; + + /* + * I've seen I2C read failures if we poll too fast after the sensor + * reset. Slight delay gives I2C block the time to recover. + */ + msleep(1); + + ret = regmap_read_poll_timeout(data->regmap, KX022A_REG_CNTL2, val, + !(val & KX022A_MASK_SRST), + KX022A_SOFT_RESET_WAIT_TIME_US, + KX022A_SOFT_RESET_TOTAL_WAIT_TIME_US); + if (ret) { + dev_err(data->dev, "Sensor reset %s\n", + val & KX022A_MASK_SRST ? "timeout" : "fail#"); + return ret; + } + + ret = regmap_reinit_cache(data->regmap, &kx022a_regmap); + if (ret) { + dev_err(data->dev, "Failed to reinit reg cache\n"); + return ret; + } + + /* set data res 16bit */ + ret = regmap_set_bits(data->regmap, KX022A_REG_BUF_CNTL2, + KX022A_MASK_BRES16); + if (ret) { + dev_err(data->dev, "Failed to set data resolution\n"); + return ret; + } + + return kx022a_prepare_irq_pin(data); +} + +int kx022a_probe_internal(struct device *dev) +{ + static const char * const regulator_names[] = {"io-vdd", "vdd"}; + struct iio_trigger *indio_trig; + struct fwnode_handle *fwnode; + struct kx022a_data *data; + struct regmap *regmap; + unsigned int chip_id; + struct iio_dev *idev; + int ret, irq; + char *name; + + regmap = dev_get_regmap(dev, NULL); + if (!regmap) { + dev_err(dev, "no regmap\n"); + return -EINVAL; + } + + fwnode = dev_fwnode(dev); + if (!fwnode) + return -ENODEV; + + idev = devm_iio_device_alloc(dev, sizeof(*data)); + if (!idev) + return -ENOMEM; + + data = iio_priv(idev); + + /* + * VDD is the analog and digital domain voltage supply and + * IO_VDD is the digital I/O voltage supply. + */ + ret = devm_regulator_bulk_get_enable(dev, ARRAY_SIZE(regulator_names), + regulator_names); + if (ret && ret != -ENODEV) + return dev_err_probe(dev, ret, "failed to enable regulator\n"); + + ret = regmap_read(regmap, KX022A_REG_WHO, &chip_id); + if (ret) + return dev_err_probe(dev, ret, "Failed to access sensor\n"); + + if (chip_id != KX022A_ID) { + dev_err(dev, "unsupported device 0x%x\n", chip_id); + return -EINVAL; + } + + irq = fwnode_irq_get_byname(fwnode, "INT1"); + if (irq > 0) { + data->inc_reg = KX022A_REG_INC1; + data->ien_reg = KX022A_REG_INC4; + } else { + irq = fwnode_irq_get_byname(fwnode, "INT2"); + if (irq <= 0) + return dev_err_probe(dev, irq, "No suitable IRQ\n"); + + data->inc_reg = KX022A_REG_INC5; + data->ien_reg = KX022A_REG_INC6; + } + + data->regmap = regmap; + data->dev = dev; + data->irq = irq; + data->odr_ns = KX022A_DEFAULT_PERIOD_NS; + mutex_init(&data->mutex); + + idev->channels = kx022a_channels; + idev->num_channels = ARRAY_SIZE(kx022a_channels); + idev->name = "kx022-accel"; + idev->info = &kx022a_info; + idev->modes = INDIO_DIRECT_MODE | INDIO_BUFFER_SOFTWARE; + idev->available_scan_masks = kx022a_scan_masks; + + /* Read the mounting matrix, if present */ + ret = iio_read_mount_matrix(dev, &data->orientation); + if (ret) + return ret; + + /* The sensor must be turned off for configuration */ + ret = kx022a_turn_off_lock(data); + if (ret) + return ret; + + ret = kx022a_chip_init(data); + if (ret) { + mutex_unlock(&data->mutex); + return ret; + } + + ret = kx022a_turn_on_unlock(data); + if (ret) + return ret; + + ret = devm_iio_triggered_buffer_setup_ext(dev, idev, + &iio_pollfunc_store_time, + kx022a_trigger_handler, + IIO_BUFFER_DIRECTION_IN, + &kx022a_buffer_ops, + kx022a_fifo_attributes); + + if (ret) + return dev_err_probe(data->dev, ret, + "iio_triggered_buffer_setup_ext FAIL\n"); + indio_trig = devm_iio_trigger_alloc(dev, "%sdata-rdy-dev%d", idev->name, + iio_device_id(idev)); + if (!indio_trig) + return -ENOMEM; + + data->trig = indio_trig; + + indio_trig->ops = &kx022a_trigger_ops; + iio_trigger_set_drvdata(indio_trig, data); + + /* + * No need to check for NULL. request_threaded_irq() defaults to + * dev_name() should the alloc fail. + */ + name = devm_kasprintf(data->dev, GFP_KERNEL, "%s-kx022a", + dev_name(data->dev)); + + ret = devm_request_threaded_irq(data->dev, irq, kx022a_irq_handler, + &kx022a_irq_thread_handler, + IRQF_ONESHOT, name, idev); + if (ret) + return dev_err_probe(data->dev, ret, "Could not request IRQ\n"); + + + ret = devm_iio_trigger_register(dev, indio_trig); + if (ret) + return dev_err_probe(data->dev, ret, + "Trigger registration failed\n"); + + ret = devm_iio_device_register(data->dev, idev); + if (ret < 0) + return dev_err_probe(dev, ret, + "Unable to register iio device\n"); + + return ret; +} +EXPORT_SYMBOL_NS_GPL(kx022a_probe_internal, IIO_KX022A); + +MODULE_DESCRIPTION("ROHM/Kionix KX022A accelerometer driver"); +MODULE_AUTHOR("Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>"); +MODULE_LICENSE("GPL"); |