| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * Driver for Chrome OS EC Sensor hub FIFO. |
| * |
| * Copyright 2020 Google LLC |
| */ |
| |
| #include <linux/delay.h> |
| #include <linux/device.h> |
| #include <linux/iio/iio.h> |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <linux/platform_data/cros_ec_commands.h> |
| #include <linux/platform_data/cros_ec_proto.h> |
| #include <linux/platform_data/cros_ec_sensorhub.h> |
| #include <linux/platform_device.h> |
| #include <linux/sort.h> |
| #include <linux/slab.h> |
| |
| #define CREATE_TRACE_POINTS |
| #include "cros_ec_sensorhub_trace.h" |
| |
| /* Precision of fixed point for the m values from the filter */ |
| #define M_PRECISION BIT(23) |
| |
| /* Only activate the filter once we have at least this many elements. */ |
| #define TS_HISTORY_THRESHOLD 8 |
| |
| /* |
| * If we don't have any history entries for this long, empty the filter to |
| * make sure there are no big discontinuities. |
| */ |
| #define TS_HISTORY_BORED_US 500000 |
| |
| /* To measure by how much the filter is overshooting, if it happens. */ |
| #define FUTURE_TS_ANALYTICS_COUNT_MAX 100 |
| |
| static inline int |
| cros_sensorhub_send_sample(struct cros_ec_sensorhub *sensorhub, |
| struct cros_ec_sensors_ring_sample *sample) |
| { |
| cros_ec_sensorhub_push_data_cb_t cb; |
| int id = sample->sensor_id; |
| struct iio_dev *indio_dev; |
| |
| if (id >= sensorhub->sensor_num) |
| return -EINVAL; |
| |
| cb = sensorhub->push_data[id].push_data_cb; |
| if (!cb) |
| return 0; |
| |
| indio_dev = sensorhub->push_data[id].indio_dev; |
| |
| if (sample->flag & MOTIONSENSE_SENSOR_FLAG_FLUSH) |
| return 0; |
| |
| return cb(indio_dev, sample->vector, sample->timestamp); |
| } |
| |
| /** |
| * cros_ec_sensorhub_register_push_data() - register the callback to the hub. |
| * |
| * @sensorhub : Sensor Hub object |
| * @sensor_num : The sensor the caller is interested in. |
| * @indio_dev : The iio device to use when a sample arrives. |
| * @cb : The callback to call when a sample arrives. |
| * |
| * The callback cb will be used by cros_ec_sensorhub_ring to distribute events |
| * from the EC. |
| * |
| * Return: 0 when callback is registered. |
| * EINVAL is the sensor number is invalid or the slot already used. |
| */ |
| int cros_ec_sensorhub_register_push_data(struct cros_ec_sensorhub *sensorhub, |
| u8 sensor_num, |
| struct iio_dev *indio_dev, |
| cros_ec_sensorhub_push_data_cb_t cb) |
| { |
| if (sensor_num >= sensorhub->sensor_num) |
| return -EINVAL; |
| if (sensorhub->push_data[sensor_num].indio_dev) |
| return -EINVAL; |
| |
| sensorhub->push_data[sensor_num].indio_dev = indio_dev; |
| sensorhub->push_data[sensor_num].push_data_cb = cb; |
| |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(cros_ec_sensorhub_register_push_data); |
| |
| void cros_ec_sensorhub_unregister_push_data(struct cros_ec_sensorhub *sensorhub, |
| u8 sensor_num) |
| { |
| sensorhub->push_data[sensor_num].indio_dev = NULL; |
| sensorhub->push_data[sensor_num].push_data_cb = NULL; |
| } |
| EXPORT_SYMBOL_GPL(cros_ec_sensorhub_unregister_push_data); |
| |
| /** |
| * cros_ec_sensorhub_ring_fifo_enable() - Enable or disable interrupt generation |
| * for FIFO events. |
| * @sensorhub: Sensor Hub object |
| * @on: true when events are requested. |
| * |
| * To be called before sleeping or when noone is listening. |
| * Return: 0 on success, or an error when we can not communicate with the EC. |
| * |
| */ |
| int cros_ec_sensorhub_ring_fifo_enable(struct cros_ec_sensorhub *sensorhub, |
| bool on) |
| { |
| int ret, i; |
| |
| mutex_lock(&sensorhub->cmd_lock); |
| if (sensorhub->tight_timestamps) |
| for (i = 0; i < sensorhub->sensor_num; i++) |
| sensorhub->batch_state[i].last_len = 0; |
| |
| sensorhub->params->cmd = MOTIONSENSE_CMD_FIFO_INT_ENABLE; |
| sensorhub->params->fifo_int_enable.enable = on; |
| |
| sensorhub->msg->outsize = sizeof(struct ec_params_motion_sense); |
| sensorhub->msg->insize = sizeof(struct ec_response_motion_sense); |
| |
| ret = cros_ec_cmd_xfer_status(sensorhub->ec->ec_dev, sensorhub->msg); |
| mutex_unlock(&sensorhub->cmd_lock); |
| |
| /* We expect to receive a payload of 4 bytes, ignore. */ |
| if (ret > 0) |
| ret = 0; |
| |
| return ret; |
| } |
| |
| static int cros_ec_sensor_ring_median_cmp(const void *pv1, const void *pv2) |
| { |
| s64 v1 = *(s64 *)pv1; |
| s64 v2 = *(s64 *)pv2; |
| |
| if (v1 > v2) |
| return 1; |
| else if (v1 < v2) |
| return -1; |
| else |
| return 0; |
| } |
| |
| /* |
| * cros_ec_sensor_ring_median: Gets median of an array of numbers |
| * |
| * For now it's implemented using an inefficient > O(n) sort then return |
| * the middle element. A more optimal method would be something like |
| * quickselect, but given that n = 64 we can probably live with it in the |
| * name of clarity. |
| * |
| * Warning: the input array gets modified (sorted)! |
| */ |
| static s64 cros_ec_sensor_ring_median(s64 *array, size_t length) |
| { |
| sort(array, length, sizeof(s64), cros_ec_sensor_ring_median_cmp, NULL); |
| return array[length / 2]; |
| } |
| |
| /* |
| * IRQ Timestamp Filtering |
| * |
| * Lower down in cros_ec_sensor_ring_process_event(), for each sensor event |
| * we have to calculate it's timestamp in the AP timebase. There are 3 time |
| * points: |
| * a - EC timebase, sensor event |
| * b - EC timebase, IRQ |
| * c - AP timebase, IRQ |
| * a' - what we want: sensor even in AP timebase |
| * |
| * While a and b are recorded at accurate times (due to the EC real time |
| * nature); c is pretty untrustworthy, even though it's recorded the |
| * first thing in ec_irq_handler(). There is a very good change we'll get |
| * added lantency due to: |
| * other irqs |
| * ddrfreq |
| * cpuidle |
| * |
| * Normally a' = c - b + a, but if we do that naive math any jitter in c |
| * will get coupled in a', which we don't want. We want a function |
| * a' = cros_ec_sensor_ring_ts_filter(a) which will filter out outliers in c. |
| * |
| * Think of a graph of AP time(b) on the y axis vs EC time(c) on the x axis. |
| * The slope of the line won't be exactly 1, there will be some clock drift |
| * between the 2 chips for various reasons (mechanical stress, temperature, |
| * voltage). We need to extrapolate values for a future x, without trusting |
| * recent y values too much. |
| * |
| * We use a median filter for the slope, then another median filter for the |
| * y-intercept to calculate this function: |
| * dx[n] = x[n-1] - x[n] |
| * dy[n] = x[n-1] - x[n] |
| * m[n] = dy[n] / dx[n] |
| * median_m = median(m[n-k:n]) |
| * error[i] = y[n-i] - median_m * x[n-i] |
| * median_error = median(error[:k]) |
| * predicted_y = median_m * x + median_error |
| * |
| * Implementation differences from above: |
| * - Redefined y to be actually c - b, this gives us a lot more precision |
| * to do the math. (c-b)/b variations are more obvious than c/b variations. |
| * - Since we don't have floating point, any operations involving slope are |
| * done using fixed point math (*M_PRECISION) |
| * - Since x and y grow with time, we keep zeroing the graph (relative to |
| * the last sample), this way math involving *x[n-i] will not overflow |
| * - EC timestamps are kept in us, it improves the slope calculation precision |
| */ |
| |
| /** |
| * cros_ec_sensor_ring_ts_filter_update() - Update filter history. |
| * |
| * @state: Filter information. |
| * @b: IRQ timestamp, EC timebase (us) |
| * @c: IRQ timestamp, AP timebase (ns) |
| * |
| * Given a new IRQ timestamp pair (EC and AP timebases), add it to the filter |
| * history. |
| */ |
| static void |
| cros_ec_sensor_ring_ts_filter_update(struct cros_ec_sensors_ts_filter_state |
| *state, |
| s64 b, s64 c) |
| { |
| s64 x, y; |
| s64 dx, dy; |
| s64 m; /* stored as *M_PRECISION */ |
| s64 *m_history_copy = state->temp_buf; |
| s64 *error = state->temp_buf; |
| int i; |
| |
| /* we trust b the most, that'll be our independent variable */ |
| x = b; |
| /* y is the offset between AP and EC times, in ns */ |
| y = c - b * 1000; |
| |
| dx = (state->x_history[0] + state->x_offset) - x; |
| if (dx == 0) |
| return; /* we already have this irq in the history */ |
| dy = (state->y_history[0] + state->y_offset) - y; |
| m = div64_s64(dy * M_PRECISION, dx); |
| |
| /* Empty filter if we haven't seen any action in a while. */ |
| if (-dx > TS_HISTORY_BORED_US) |
| state->history_len = 0; |
| |
| /* Move everything over, also update offset to all absolute coords .*/ |
| for (i = state->history_len - 1; i >= 1; i--) { |
| state->x_history[i] = state->x_history[i - 1] + dx; |
| state->y_history[i] = state->y_history[i - 1] + dy; |
| |
| state->m_history[i] = state->m_history[i - 1]; |
| /* |
| * Also use the same loop to copy m_history for future |
| * median extraction. |
| */ |
| m_history_copy[i] = state->m_history[i - 1]; |
| } |
| |
| /* Store the x and y, but remember offset is actually last sample. */ |
| state->x_offset = x; |
| state->y_offset = y; |
| state->x_history[0] = 0; |
| state->y_history[0] = 0; |
| |
| state->m_history[0] = m; |
| m_history_copy[0] = m; |
| |
| if (state->history_len < CROS_EC_SENSORHUB_TS_HISTORY_SIZE) |
| state->history_len++; |
| |
| /* Precalculate things for the filter. */ |
| if (state->history_len > TS_HISTORY_THRESHOLD) { |
| state->median_m = |
| cros_ec_sensor_ring_median(m_history_copy, |
| state->history_len - 1); |
| |
| /* |
| * Calculate y-intercepts as if m_median is the slope and |
| * points in the history are on the line. median_error will |
| * still be in the offset coordinate system. |
| */ |
| for (i = 0; i < state->history_len; i++) |
| error[i] = state->y_history[i] - |
| div_s64(state->median_m * state->x_history[i], |
| M_PRECISION); |
| state->median_error = |
| cros_ec_sensor_ring_median(error, state->history_len); |
| } else { |
| state->median_m = 0; |
| state->median_error = 0; |
| } |
| trace_cros_ec_sensorhub_filter(state, dx, dy); |
| } |
| |
| /** |
| * cros_ec_sensor_ring_ts_filter() - Translate EC timebase timestamp to AP |
| * timebase |
| * |
| * @state: filter information. |
| * @x: any ec timestamp (us): |
| * |
| * cros_ec_sensor_ring_ts_filter(a) => a' event timestamp, AP timebase |
| * cros_ec_sensor_ring_ts_filter(b) => calculated timestamp when the EC IRQ |
| * should have happened on the AP, with low jitter |
| * |
| * Note: The filter will only activate once state->history_len goes |
| * over TS_HISTORY_THRESHOLD. Otherwise it'll just do the naive c - b + a |
| * transform. |
| * |
| * How to derive the formula, starting from: |
| * f(x) = median_m * x + median_error |
| * That's the calculated AP - EC offset (at the x point in time) |
| * Undo the coordinate system transform: |
| * f(x) = median_m * (x - x_offset) + median_error + y_offset |
| * Remember to undo the "y = c - b * 1000" modification: |
| * f(x) = median_m * (x - x_offset) + median_error + y_offset + x * 1000 |
| * |
| * Return: timestamp in AP timebase (ns) |
| */ |
| static s64 |
| cros_ec_sensor_ring_ts_filter(struct cros_ec_sensors_ts_filter_state *state, |
| s64 x) |
| { |
| return div_s64(state->median_m * (x - state->x_offset), M_PRECISION) |
| + state->median_error + state->y_offset + x * 1000; |
| } |
| |
| /* |
| * Since a and b were originally 32 bit values from the EC, |
| * they overflow relatively often, casting is not enough, so we need to |
| * add an offset. |
| */ |
| static void |
| cros_ec_sensor_ring_fix_overflow(s64 *ts, |
| const s64 overflow_period, |
| struct cros_ec_sensors_ec_overflow_state |
| *state) |
| { |
| s64 adjust; |
| |
| *ts += state->offset; |
| if (abs(state->last - *ts) > (overflow_period / 2)) { |
| adjust = state->last > *ts ? overflow_period : -overflow_period; |
| state->offset += adjust; |
| *ts += adjust; |
| } |
| state->last = *ts; |
| } |
| |
| static void |
| cros_ec_sensor_ring_check_for_past_timestamp(struct cros_ec_sensorhub |
| *sensorhub, |
| struct cros_ec_sensors_ring_sample |
| *sample) |
| { |
| const u8 sensor_id = sample->sensor_id; |
| |
| /* If this event is earlier than one we saw before... */ |
| if (sensorhub->batch_state[sensor_id].newest_sensor_event > |
| sample->timestamp) |
| /* mark it for spreading. */ |
| sample->timestamp = |
| sensorhub->batch_state[sensor_id].last_ts; |
| else |
| sensorhub->batch_state[sensor_id].newest_sensor_event = |
| sample->timestamp; |
| } |
| |
| /** |
| * cros_ec_sensor_ring_process_event() - Process one EC FIFO event |
| * |
| * @sensorhub: Sensor Hub object. |
| * @fifo_info: FIFO information from the EC (includes b point, EC timebase). |
| * @fifo_timestamp: EC IRQ, kernel timebase (aka c). |
| * @current_timestamp: calculated event timestamp, kernel timebase (aka a'). |
| * @in: incoming FIFO event from EC (includes a point, EC timebase). |
| * @out: outgoing event to user space (includes a'). |
| * |
| * Process one EC event, add it in the ring if necessary. |
| * |
| * Return: true if out event has been populated. |
| */ |
| static bool |
| cros_ec_sensor_ring_process_event(struct cros_ec_sensorhub *sensorhub, |
| const struct ec_response_motion_sense_fifo_info |
| *fifo_info, |
| const ktime_t fifo_timestamp, |
| ktime_t *current_timestamp, |
| struct ec_response_motion_sensor_data *in, |
| struct cros_ec_sensors_ring_sample *out) |
| { |
| const s64 now = cros_ec_get_time_ns(); |
| int axis, async_flags; |
| |
| /* Do not populate the filter based on asynchronous events. */ |
| async_flags = in->flags & |
| (MOTIONSENSE_SENSOR_FLAG_ODR | MOTIONSENSE_SENSOR_FLAG_FLUSH); |
| |
| if (in->flags & MOTIONSENSE_SENSOR_FLAG_TIMESTAMP && !async_flags) { |
| s64 a = in->timestamp; |
| s64 b = fifo_info->timestamp; |
| s64 c = fifo_timestamp; |
| |
| cros_ec_sensor_ring_fix_overflow(&a, 1LL << 32, |
| &sensorhub->overflow_a); |
| cros_ec_sensor_ring_fix_overflow(&b, 1LL << 32, |
| &sensorhub->overflow_b); |
| |
| if (sensorhub->tight_timestamps) { |
| cros_ec_sensor_ring_ts_filter_update( |
| &sensorhub->filter, b, c); |
| *current_timestamp = cros_ec_sensor_ring_ts_filter( |
| &sensorhub->filter, a); |
| } else { |
| s64 new_timestamp; |
| |
| /* |
| * Disable filtering since we might add more jitter |
| * if b is in a random point in time. |
| */ |
| new_timestamp = c - b * 1000 + a * 1000; |
| /* |
| * The timestamp can be stale if we had to use the fifo |
| * info timestamp. |
| */ |
| if (new_timestamp - *current_timestamp > 0) |
| *current_timestamp = new_timestamp; |
| } |
| trace_cros_ec_sensorhub_timestamp(in->timestamp, |
| fifo_info->timestamp, |
| fifo_timestamp, |
| *current_timestamp, |
| now); |
| } |
| |
| if (in->flags & MOTIONSENSE_SENSOR_FLAG_ODR) { |
| if (sensorhub->tight_timestamps) { |
| sensorhub->batch_state[in->sensor_num].last_len = 0; |
| sensorhub->batch_state[in->sensor_num].penul_len = 0; |
| } |
| /* |
| * ODR change is only useful for the sensor_ring, it does not |
| * convey information to clients. |
| */ |
| return false; |
| } |
| |
| if (in->flags & MOTIONSENSE_SENSOR_FLAG_FLUSH) { |
| out->sensor_id = in->sensor_num; |
| out->timestamp = *current_timestamp; |
| out->flag = in->flags; |
| if (sensorhub->tight_timestamps) |
| sensorhub->batch_state[out->sensor_id].last_len = 0; |
| /* |
| * No other payload information provided with |
| * flush ack. |
| */ |
| return true; |
| } |
| |
| if (in->flags & MOTIONSENSE_SENSOR_FLAG_TIMESTAMP) |
| /* If we just have a timestamp, skip this entry. */ |
| return false; |
| |
| /* Regular sample */ |
| out->sensor_id = in->sensor_num; |
| trace_cros_ec_sensorhub_data(in->sensor_num, |
| fifo_info->timestamp, |
| fifo_timestamp, |
| *current_timestamp, |
| now); |
| |
| if (*current_timestamp - now > 0) { |
| /* |
| * This fix is needed to overcome the timestamp filter putting |
| * events in the future. |
| */ |
| sensorhub->future_timestamp_total_ns += |
| *current_timestamp - now; |
| if (++sensorhub->future_timestamp_count == |
| FUTURE_TS_ANALYTICS_COUNT_MAX) { |
| s64 avg = div_s64(sensorhub->future_timestamp_total_ns, |
| sensorhub->future_timestamp_count); |
| dev_warn_ratelimited(sensorhub->dev, |
| "100 timestamps in the future, %lldns shaved on average\n", |
| avg); |
| sensorhub->future_timestamp_count = 0; |
| sensorhub->future_timestamp_total_ns = 0; |
| } |
| out->timestamp = now; |
| } else { |
| out->timestamp = *current_timestamp; |
| } |
| |
| out->flag = in->flags; |
| for (axis = 0; axis < 3; axis++) |
| out->vector[axis] = in->data[axis]; |
| |
| if (sensorhub->tight_timestamps) |
| cros_ec_sensor_ring_check_for_past_timestamp(sensorhub, out); |
| return true; |
| } |
| |
| /* |
| * cros_ec_sensor_ring_spread_add: Calculate proper timestamps then add to |
| * ringbuffer. |
| * |
| * This is the new spreading code, assumes every sample's timestamp |
| * preceeds the sample. Run if tight_timestamps == true. |
| * |
| * Sometimes the EC receives only one interrupt (hence timestamp) for |
| * a batch of samples. Only the first sample will have the correct |
| * timestamp. So we must interpolate the other samples. |
| * We use the previous batch timestamp and our current batch timestamp |
| * as a way to calculate period, then spread the samples evenly. |
| * |
| * s0 int, 0ms |
| * s1 int, 10ms |
| * s2 int, 20ms |
| * 30ms point goes by, no interrupt, previous one is still asserted |
| * downloading s2 and s3 |
| * s3 sample, 20ms (incorrect timestamp) |
| * s4 int, 40ms |
| * |
| * The batches are [(s0), (s1), (s2, s3), (s4)]. Since the 3rd batch |
| * has 2 samples in them, we adjust the timestamp of s3. |
| * s2 - s1 = 10ms, so s3 must be s2 + 10ms => 20ms. If s1 would have |
| * been part of a bigger batch things would have gotten a little |
| * more complicated. |
| * |
| * Note: we also assume another sensor sample doesn't break up a batch |
| * in 2 or more partitions. Example, there can't ever be a sync sensor |
| * in between S2 and S3. This simplifies the following code. |
| */ |
| static void |
| cros_ec_sensor_ring_spread_add(struct cros_ec_sensorhub *sensorhub, |
| unsigned long sensor_mask, |
| struct cros_ec_sensors_ring_sample *last_out) |
| { |
| struct cros_ec_sensors_ring_sample *batch_start, *next_batch_start; |
| int id; |
| |
| for_each_set_bit(id, &sensor_mask, sensorhub->sensor_num) { |
| for (batch_start = sensorhub->ring; batch_start < last_out; |
| batch_start = next_batch_start) { |
| /* |
| * For each batch (where all samples have the same |
| * timestamp). |
| */ |
| int batch_len, sample_idx; |
| struct cros_ec_sensors_ring_sample *batch_end = |
| batch_start; |
| struct cros_ec_sensors_ring_sample *s; |
| s64 batch_timestamp = batch_start->timestamp; |
| s64 sample_period; |
| |
| /* |
| * Skip over batches that start with the sensor types |
| * we're not looking at right now. |
| */ |
| if (batch_start->sensor_id != id) { |
| next_batch_start = batch_start + 1; |
| continue; |
| } |
| |
| /* |
| * Do not start a batch |
| * from a flush, as it happens asynchronously to the |
| * regular flow of events. |
| */ |
| if (batch_start->flag & MOTIONSENSE_SENSOR_FLAG_FLUSH) { |
| cros_sensorhub_send_sample(sensorhub, |
| batch_start); |
| next_batch_start = batch_start + 1; |
| continue; |
| } |
| |
| if (batch_start->timestamp <= |
| sensorhub->batch_state[id].last_ts) { |
| batch_timestamp = |
| sensorhub->batch_state[id].last_ts; |
| batch_len = sensorhub->batch_state[id].last_len; |
| |
| sample_idx = batch_len; |
| |
| sensorhub->batch_state[id].last_ts = |
| sensorhub->batch_state[id].penul_ts; |
| sensorhub->batch_state[id].last_len = |
| sensorhub->batch_state[id].penul_len; |
| } else { |
| /* |
| * Push first sample in the batch to the, |
| * kifo, it's guaranteed to be correct, the |
| * rest will follow later on. |
| */ |
| sample_idx = 1; |
| batch_len = 1; |
| cros_sensorhub_send_sample(sensorhub, |
| batch_start); |
| batch_start++; |
| } |
| |
| /* Find all samples have the same timestamp. */ |
| for (s = batch_start; s < last_out; s++) { |
| if (s->sensor_id != id) |
| /* |
| * Skip over other sensor types that |
| * are interleaved, don't count them. |
| */ |
| continue; |
| if (s->timestamp != batch_timestamp) |
| /* we discovered the next batch */ |
| break; |
| if (s->flag & MOTIONSENSE_SENSOR_FLAG_FLUSH) |
| /* break on flush packets */ |
| break; |
| batch_end = s; |
| batch_len++; |
| } |
| |
| if (batch_len == 1) |
| goto done_with_this_batch; |
| |
| /* Can we calculate period? */ |
| if (sensorhub->batch_state[id].last_len == 0) { |
| dev_warn(sensorhub->dev, "Sensor %d: lost %d samples when spreading\n", |
| id, batch_len - 1); |
| goto done_with_this_batch; |
| /* |
| * Note: we're dropping the rest of the samples |
| * in this batch since we have no idea where |
| * they're supposed to go without a period |
| * calculation. |
| */ |
| } |
| |
| sample_period = div_s64(batch_timestamp - |
| sensorhub->batch_state[id].last_ts, |
| sensorhub->batch_state[id].last_len); |
| dev_dbg(sensorhub->dev, |
| "Adjusting %d samples, sensor %d last_batch @%lld (%d samples) batch_timestamp=%lld => period=%lld\n", |
| batch_len, id, |
| sensorhub->batch_state[id].last_ts, |
| sensorhub->batch_state[id].last_len, |
| batch_timestamp, |
| sample_period); |
| |
| /* |
| * Adjust timestamps of the samples then push them to |
| * kfifo. |
| */ |
| for (s = batch_start; s <= batch_end; s++) { |
| if (s->sensor_id != id) |
| /* |
| * Skip over other sensor types that |
| * are interleaved, don't change them. |
| */ |
| continue; |
| |
| s->timestamp = batch_timestamp + |
| sample_period * sample_idx; |
| sample_idx++; |
| |
| cros_sensorhub_send_sample(sensorhub, s); |
| } |
| |
| done_with_this_batch: |
| sensorhub->batch_state[id].penul_ts = |
| sensorhub->batch_state[id].last_ts; |
| sensorhub->batch_state[id].penul_len = |
| sensorhub->batch_state[id].last_len; |
| |
| sensorhub->batch_state[id].last_ts = |
| batch_timestamp; |
| sensorhub->batch_state[id].last_len = batch_len; |
| |
| next_batch_start = batch_end + 1; |
| } |
| } |
| } |
| |
| /* |
| * cros_ec_sensor_ring_spread_add_legacy: Calculate proper timestamps then |
| * add to ringbuffer (legacy). |
| * |
| * Note: This assumes we're running old firmware, where timestamp |
| * is inserted after its sample(s)e. There can be several samples between |
| * timestamps, so several samples can have the same timestamp. |
| * |
| * timestamp | count |
| * ----------------- |
| * 1st sample --> TS1 | 1 |
| * TS2 | 2 |
| * TS2 | 3 |
| * TS3 | 4 |
| * last_out --> |
| * |
| * |
| * We spread time for the samples using perod p = (current - TS1)/4. |
| * between TS1 and TS2: [TS1+p/4, TS1+2p/4, TS1+3p/4, current_timestamp]. |
| * |
| */ |
| static void |
| cros_ec_sensor_ring_spread_add_legacy(struct cros_ec_sensorhub *sensorhub, |
| unsigned long sensor_mask, |
| s64 current_timestamp, |
| struct cros_ec_sensors_ring_sample |
| *last_out) |
| { |
| struct cros_ec_sensors_ring_sample *out; |
| int i; |
| |
| for_each_set_bit(i, &sensor_mask, sensorhub->sensor_num) { |
| s64 timestamp; |
| int count = 0; |
| s64 time_period; |
| |
| for (out = sensorhub->ring; out < last_out; out++) { |
| if (out->sensor_id != i) |
| continue; |
| |
| /* Timestamp to start with */ |
| timestamp = out->timestamp; |
| out++; |
| count = 1; |
| break; |
| } |
| for (; out < last_out; out++) { |
| /* Find last sample. */ |
| if (out->sensor_id != i) |
| continue; |
| count++; |
| } |
| if (count == 0) |
| continue; |
| |
| /* Spread uniformly between the first and last samples. */ |
| time_period = div_s64(current_timestamp - timestamp, count); |
| |
| for (out = sensorhub->ring; out < last_out; out++) { |
| if (out->sensor_id != i) |
| continue; |
| timestamp += time_period; |
| out->timestamp = timestamp; |
| } |
| } |
| |
| /* Push the event into the kfifo */ |
| for (out = sensorhub->ring; out < last_out; out++) |
| cros_sensorhub_send_sample(sensorhub, out); |
| } |
| |
| /** |
| * cros_ec_sensorhub_ring_handler() - The trigger handler function |
| * |
| * @sensorhub: Sensor Hub object. |
| * |
| * Called by the notifier, process the EC sensor FIFO queue. |
| */ |
| static void cros_ec_sensorhub_ring_handler(struct cros_ec_sensorhub *sensorhub) |
| { |
| struct ec_response_motion_sense_fifo_info *fifo_info = |
| sensorhub->fifo_info; |
| struct cros_ec_dev *ec = sensorhub->ec; |
| ktime_t fifo_timestamp, current_timestamp; |
| int i, j, number_data, ret; |
| unsigned long sensor_mask = 0; |
| struct ec_response_motion_sensor_data *in; |
| struct cros_ec_sensors_ring_sample *out, *last_out; |
| |
| mutex_lock(&sensorhub->cmd_lock); |
| |
| /* Get FIFO information if there are lost vectors. */ |
| if (fifo_info->total_lost) { |
| int fifo_info_length = |
| sizeof(struct ec_response_motion_sense_fifo_info) + |
| sizeof(u16) * sensorhub->sensor_num; |
| |
| /* Need to retrieve the number of lost vectors per sensor */ |
| sensorhub->params->cmd = MOTIONSENSE_CMD_FIFO_INFO; |
| sensorhub->msg->outsize = 1; |
| sensorhub->msg->insize = fifo_info_length; |
| |
| if (cros_ec_cmd_xfer_status(ec->ec_dev, sensorhub->msg) < 0) |
| goto error; |
| |
| memcpy(fifo_info, &sensorhub->resp->fifo_info, |
| fifo_info_length); |
| |
| /* |
| * Update collection time, will not be as precise as the |
| * non-error case. |
| */ |
| fifo_timestamp = cros_ec_get_time_ns(); |
| } else { |
| fifo_timestamp = sensorhub->fifo_timestamp[ |
| CROS_EC_SENSOR_NEW_TS]; |
| } |
| |
| if (fifo_info->count > sensorhub->fifo_size || |
| fifo_info->size != sensorhub->fifo_size) { |
| dev_warn(sensorhub->dev, |
| "Mismatch EC data: count %d, size %d - expected %d\n", |
| fifo_info->count, fifo_info->size, |
| sensorhub->fifo_size); |
| goto error; |
| } |
| |
| /* Copy elements in the main fifo */ |
| current_timestamp = sensorhub->fifo_timestamp[CROS_EC_SENSOR_LAST_TS]; |
| out = sensorhub->ring; |
| for (i = 0; i < fifo_info->count; i += number_data) { |
| sensorhub->params->cmd = MOTIONSENSE_CMD_FIFO_READ; |
| sensorhub->params->fifo_read.max_data_vector = |
| fifo_info->count - i; |
| sensorhub->msg->outsize = |
| sizeof(struct ec_params_motion_sense); |
| sensorhub->msg->insize = |
| sizeof(sensorhub->resp->fifo_read) + |
| sensorhub->params->fifo_read.max_data_vector * |
| sizeof(struct ec_response_motion_sensor_data); |
| ret = cros_ec_cmd_xfer_status(ec->ec_dev, sensorhub->msg); |
| if (ret < 0) { |
| dev_warn(sensorhub->dev, "Fifo error: %d\n", ret); |
| break; |
| } |
| number_data = sensorhub->resp->fifo_read.number_data; |
| if (number_data == 0) { |
| dev_dbg(sensorhub->dev, "Unexpected empty FIFO\n"); |
| break; |
| } |
| if (number_data > fifo_info->count - i) { |
| dev_warn(sensorhub->dev, |
| "Invalid EC data: too many entry received: %d, expected %d\n", |
| number_data, fifo_info->count - i); |
| break; |
| } |
| if (out + number_data > |
| sensorhub->ring + fifo_info->count) { |
| dev_warn(sensorhub->dev, |
| "Too many samples: %d (%zd data) to %d entries for expected %d entries\n", |
| i, out - sensorhub->ring, i + number_data, |
| fifo_info->count); |
| break; |
| } |
| |
| for (in = sensorhub->resp->fifo_read.data, j = 0; |
| j < number_data; j++, in++) { |
| if (cros_ec_sensor_ring_process_event( |
| sensorhub, fifo_info, |
| fifo_timestamp, |
| ¤t_timestamp, |
| in, out)) { |
| sensor_mask |= BIT(in->sensor_num); |
| out++; |
| } |
| } |
| } |
| mutex_unlock(&sensorhub->cmd_lock); |
| last_out = out; |
| |
| if (out == sensorhub->ring) |
| /* Unexpected empty FIFO. */ |
| goto ring_handler_end; |
| |
| /* |
| * Check if current_timestamp is ahead of the last sample. Normally, |
| * the EC appends a timestamp after the last sample, but if the AP |
| * is slow to respond to the IRQ, the EC may have added new samples. |
| * Use the FIFO info timestamp as last timestamp then. |
| */ |
| if (!sensorhub->tight_timestamps && |
| (last_out - 1)->timestamp == current_timestamp) |
| current_timestamp = fifo_timestamp; |
| |
| /* Warn on lost samples. */ |
| if (fifo_info->total_lost) |
| for (i = 0; i < sensorhub->sensor_num; i++) { |
| if (fifo_info->lost[i]) { |
| dev_warn_ratelimited(sensorhub->dev, |
| "Sensor %d: lost: %d out of %d\n", |
| i, fifo_info->lost[i], |
| fifo_info->total_lost); |
| if (sensorhub->tight_timestamps) |
| sensorhub->batch_state[i].last_len = 0; |
| } |
| } |
| |
| /* |
| * Spread samples in case of batching, then add them to the |
| * ringbuffer. |
| */ |
| if (sensorhub->tight_timestamps) |
| cros_ec_sensor_ring_spread_add(sensorhub, sensor_mask, |
| last_out); |
| else |
| cros_ec_sensor_ring_spread_add_legacy(sensorhub, sensor_mask, |
| current_timestamp, |
| last_out); |
| |
| ring_handler_end: |
| sensorhub->fifo_timestamp[CROS_EC_SENSOR_LAST_TS] = current_timestamp; |
| return; |
| |
| error: |
| mutex_unlock(&sensorhub->cmd_lock); |
| } |
| |
| static int cros_ec_sensorhub_event(struct notifier_block *nb, |
| unsigned long queued_during_suspend, |
| void *_notify) |
| { |
| struct cros_ec_sensorhub *sensorhub; |
| struct cros_ec_device *ec_dev; |
| |
| sensorhub = container_of(nb, struct cros_ec_sensorhub, notifier); |
| ec_dev = sensorhub->ec->ec_dev; |
| |
| if (ec_dev->event_data.event_type != EC_MKBP_EVENT_SENSOR_FIFO) |
| return NOTIFY_DONE; |
| |
| if (ec_dev->event_size != sizeof(ec_dev->event_data.data.sensor_fifo)) { |
| dev_warn(ec_dev->dev, "Invalid fifo info size\n"); |
| return NOTIFY_DONE; |
| } |
| |
| if (queued_during_suspend) |
| return NOTIFY_OK; |
| |
| memcpy(sensorhub->fifo_info, &ec_dev->event_data.data.sensor_fifo.info, |
| sizeof(*sensorhub->fifo_info)); |
| sensorhub->fifo_timestamp[CROS_EC_SENSOR_NEW_TS] = |
| ec_dev->last_event_time; |
| cros_ec_sensorhub_ring_handler(sensorhub); |
| |
| return NOTIFY_OK; |
| } |
| |
| /** |
| * cros_ec_sensorhub_ring_allocate() - Prepare the FIFO functionality if the EC |
| * supports it. |
| * |
| * @sensorhub : Sensor Hub object. |
| * |
| * Return: 0 on success. |
| */ |
| int cros_ec_sensorhub_ring_allocate(struct cros_ec_sensorhub *sensorhub) |
| { |
| int fifo_info_length = |
| sizeof(struct ec_response_motion_sense_fifo_info) + |
| sizeof(u16) * sensorhub->sensor_num; |
| |
| /* Allocate the array for lost events. */ |
| sensorhub->fifo_info = devm_kzalloc(sensorhub->dev, fifo_info_length, |
| GFP_KERNEL); |
| if (!sensorhub->fifo_info) |
| return -ENOMEM; |
| |
| /* |
| * Allocate the callback area based on the number of sensors. |
| * Add one for the sensor ring. |
| */ |
| sensorhub->push_data = devm_kcalloc(sensorhub->dev, |
| sensorhub->sensor_num, |
| sizeof(*sensorhub->push_data), |
| GFP_KERNEL); |
| if (!sensorhub->push_data) |
| return -ENOMEM; |
| |
| sensorhub->tight_timestamps = cros_ec_check_features( |
| sensorhub->ec, |
| EC_FEATURE_MOTION_SENSE_TIGHT_TIMESTAMPS); |
| |
| if (sensorhub->tight_timestamps) { |
| sensorhub->batch_state = devm_kcalloc(sensorhub->dev, |
| sensorhub->sensor_num, |
| sizeof(*sensorhub->batch_state), |
| GFP_KERNEL); |
| if (!sensorhub->batch_state) |
| return -ENOMEM; |
| } |
| |
| return 0; |
| } |
| |
| /** |
| * cros_ec_sensorhub_ring_add() - Add the FIFO functionality if the EC |
| * supports it. |
| * |
| * @sensorhub : Sensor Hub object. |
| * |
| * Return: 0 on success. |
| */ |
| int cros_ec_sensorhub_ring_add(struct cros_ec_sensorhub *sensorhub) |
| { |
| struct cros_ec_dev *ec = sensorhub->ec; |
| int ret; |
| int fifo_info_length = |
| sizeof(struct ec_response_motion_sense_fifo_info) + |
| sizeof(u16) * sensorhub->sensor_num; |
| |
| /* Retrieve FIFO information */ |
| sensorhub->msg->version = 2; |
| sensorhub->params->cmd = MOTIONSENSE_CMD_FIFO_INFO; |
| sensorhub->msg->outsize = 1; |
| sensorhub->msg->insize = fifo_info_length; |
| |
| ret = cros_ec_cmd_xfer_status(ec->ec_dev, sensorhub->msg); |
| if (ret < 0) |
| return ret; |
| |
| /* |
| * Allocate the full fifo. We need to copy the whole FIFO to set |
| * timestamps properly. |
| */ |
| sensorhub->fifo_size = sensorhub->resp->fifo_info.size; |
| sensorhub->ring = devm_kcalloc(sensorhub->dev, sensorhub->fifo_size, |
| sizeof(*sensorhub->ring), GFP_KERNEL); |
| if (!sensorhub->ring) |
| return -ENOMEM; |
| |
| sensorhub->fifo_timestamp[CROS_EC_SENSOR_LAST_TS] = |
| cros_ec_get_time_ns(); |
| |
| /* Register the notifier that will act as a top half interrupt. */ |
| sensorhub->notifier.notifier_call = cros_ec_sensorhub_event; |
| ret = blocking_notifier_chain_register(&ec->ec_dev->event_notifier, |
| &sensorhub->notifier); |
| if (ret < 0) |
| return ret; |
| |
| /* Start collection samples. */ |
| return cros_ec_sensorhub_ring_fifo_enable(sensorhub, true); |
| } |
| |
| void cros_ec_sensorhub_ring_remove(void *arg) |
| { |
| struct cros_ec_sensorhub *sensorhub = arg; |
| struct cros_ec_device *ec_dev = sensorhub->ec->ec_dev; |
| |
| /* Disable the ring, prevent EC interrupt to the AP for nothing. */ |
| cros_ec_sensorhub_ring_fifo_enable(sensorhub, false); |
| blocking_notifier_chain_unregister(&ec_dev->event_notifier, |
| &sensorhub->notifier); |
| } |