1 files changed, 51 insertions, 165 deletions

diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c b/drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c
index 548e042f7b5b..c4c11124f92f 100644
--- a/drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c
+++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c
@@ -1,14 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
 * Copyright (C) 2012 Invensense, Inc.
-*
-* This software is licensed under the terms of the GNU General Public
-* License version 2, as published by the Free Software Foundation, and
-* may be copied, distributed, and modified under those terms.
-*
-* This program is distributed in the hope that it will be useful,
-* but WITHOUT ANY WARRANTY; without even the implied warranty of
-* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-* GNU General Public License for more details.
 */
 
 #include <linux/module.h>
@@ -21,135 +13,19 @@
 #include <linux/interrupt.h>
 #include <linux/poll.h>
 #include <linux/math64.h>
-#include <asm/unaligned.h>
-#include "inv_mpu_iio.h"
-
-/**
- *  inv_mpu6050_update_period() - Update chip internal period estimation
- *
- *  @st:		driver state
- *  @timestamp:		the interrupt timestamp
- *  @nb:		number of data set in the fifo
- *
- *  This function uses interrupt timestamps to estimate the chip period and
- *  to choose the data timestamp to come.
- */
-static void inv_mpu6050_update_period(struct inv_mpu6050_state *st,
-				      s64 timestamp, size_t nb)
-{
-	/* Period boundaries for accepting timestamp */
-	const s64 period_min =
-		(NSEC_PER_MSEC * (100 - INV_MPU6050_TS_PERIOD_JITTER)) / 100;
-	const s64 period_max =
-		(NSEC_PER_MSEC * (100 + INV_MPU6050_TS_PERIOD_JITTER)) / 100;
-	const s32 divider = INV_MPU6050_FREQ_DIVIDER(st);
-	s64 delta, interval;
-	bool use_it_timestamp = false;
-
-	if (st->it_timestamp == 0) {
-		/* not initialized, forced to use it_timestamp */
-		use_it_timestamp = true;
-	} else if (nb == 1) {
-		/*
-		 * Validate the use of it timestamp by checking if interrupt
-		 * has been delayed.
-		 * nb > 1 means interrupt was delayed for more than 1 sample,
-		 * so it's obviously not good.
-		 * Compute the chip period between 2 interrupts for validating.
-		 */
-		delta = div_s64(timestamp - st->it_timestamp, divider);
-		if (delta > period_min && delta < period_max) {
-			/* update chip period and use it timestamp */
-			st->chip_period = (st->chip_period + delta) / 2;
-			use_it_timestamp = true;
-		}
-	}
-
-	if (use_it_timestamp) {
-		/*
-		 * Manage case of multiple samples in the fifo (nb > 1):
-		 * compute timestamp corresponding to the first sample using
-		 * estimated chip period.
-		 */
-		interval = (nb - 1) * st->chip_period * divider;
-		st->data_timestamp = timestamp - interval;
-	}
-
-	/* save it timestamp */
-	st->it_timestamp = timestamp;
-}
-
-/**
- *  inv_mpu6050_get_timestamp() - Return the current data timestamp
- *
- *  @st:		driver state
- *  @return:		current data timestamp
- *
- *  This function returns the current data timestamp and prepares for next one.
- */
-static s64 inv_mpu6050_get_timestamp(struct inv_mpu6050_state *st)
-{
-	s64 ts;
 
-	/* return current data timestamp and increment */
-	ts = st->data_timestamp;
-	st->data_timestamp += st->chip_period * INV_MPU6050_FREQ_DIVIDER(st);
+#include <linux/iio/common/inv_sensors_timestamp.h>
 
-	return ts;
-}
+#include "inv_mpu_iio.h"
 
-int inv_reset_fifo(struct iio_dev *indio_dev)
+static int inv_reset_fifo(struct iio_dev *indio_dev)
 {
 	int result;
-	u8 d;
 	struct inv_mpu6050_state  *st = iio_priv(indio_dev);
 
-	/* reset it timestamp validation */
-	st->it_timestamp = 0;
-
-	/* disable interrupt */
-	result = regmap_write(st->map, st->reg->int_enable, 0);
-	if (result) {
-		dev_err(regmap_get_device(st->map), "int_enable failed %d\n",
-			result);
-		return result;
-	}
-	/* disable the sensor output to FIFO */
-	result = regmap_write(st->map, st->reg->fifo_en, 0);
-	if (result)
-		goto reset_fifo_fail;
-	/* disable fifo reading */
-	result = regmap_write(st->map, st->reg->user_ctrl,
-			      st->chip_config.user_ctrl);
-	if (result)
-		goto reset_fifo_fail;
-
-	/* reset FIFO*/
-	d = st->chip_config.user_ctrl | INV_MPU6050_BIT_FIFO_RST;
-	result = regmap_write(st->map, st->reg->user_ctrl, d);
-	if (result)
-		goto reset_fifo_fail;
-
-	/* enable interrupt */
-	if (st->chip_config.accl_fifo_enable ||
-	    st->chip_config.gyro_fifo_enable) {
-		result = regmap_write(st->map, st->reg->int_enable,
-				      INV_MPU6050_BIT_DATA_RDY_EN);
-		if (result)
-			return result;
-	}
-	/* enable FIFO reading */
-	d = st->chip_config.user_ctrl | INV_MPU6050_BIT_FIFO_EN;
-	result = regmap_write(st->map, st->reg->user_ctrl, d);
-	if (result)
-		goto reset_fifo_fail;
-	/* enable sensor output to FIFO */
-	d = 0;
-	if (st->chip_config.gyro_fifo_enable)
-		d |= INV_MPU6050_BITS_GYRO_OUT;
-	if (st->chip_config.accl_fifo_enable)
-		d |= INV_MPU6050_BIT_ACCEL_OUT;
-	result = regmap_write(st->map, st->reg->fifo_en, d);
+	/* disable fifo and reenable it */
+	inv_mpu6050_prepare_fifo(st, false);
+	result = inv_mpu6050_prepare_fifo(st, true);
 	if (result)
 		goto reset_fifo_fail;
 
@@ -157,13 +33,11 @@ int inv_reset_fifo(struct iio_dev *indio_dev)
 
 reset_fifo_fail:
 	dev_err(regmap_get_device(st->map), "reset fifo failed %d\n", result);
-	result = regmap_write(st->map, st->reg->int_enable,
-			      INV_MPU6050_BIT_DATA_RDY_EN);
-
-	return result;
+	return regmap_update_bits(st->map, st->reg->int_enable,
+			INV_MPU6050_BIT_DATA_RDY_EN, INV_MPU6050_BIT_DATA_RDY_EN);
 }
 
-/**
+/*
  * inv_mpu6050_read_fifo() - Transfer data from hardware FIFO to KFIFO.
  */
 irqreturn_t inv_mpu6050_read_fifo(int irq, void *p)
@@ -173,32 +47,18 @@ irqreturn_t inv_mpu6050_read_fifo(int irq, void *p)
 	struct inv_mpu6050_state *st = iio_priv(indio_dev);
 	size_t bytes_per_datum;
 	int result;
-	u8 data[INV_MPU6050_OUTPUT_DATA_SIZE];
 	u16 fifo_count;
+	u32 fifo_period;
 	s64 timestamp;
-	int int_status;
+	/* clear internal data buffer for avoiding kernel data leak */
+	u8 data[INV_MPU6050_OUTPUT_DATA_SIZE] __aligned(8) = { };
 	size_t i, nb;
 
 	mutex_lock(&st->lock);
 
-	/* ack interrupt and check status */
-	result = regmap_read(st->map, st->reg->int_status, &int_status);
-	if (result) {
-		dev_err(regmap_get_device(st->map),
-			"failed to ack interrupt\n");
-		goto flush_fifo;
-	}
-	/* handle fifo overflow by reseting fifo */
-	if (int_status & INV_MPU6050_BIT_FIFO_OVERFLOW_INT)
-		goto flush_fifo;
-	if (!(int_status & INV_MPU6050_BIT_RAW_DATA_RDY_INT)) {
-		dev_warn(regmap_get_device(st->map),
-			"spurious interrupt with status 0x%x\n", int_status);
-		goto end_session;
-	}
-
 	if (!(st->chip_config.accl_fifo_enable |
-		st->chip_config.gyro_fifo_enable))
+		st->chip_config.gyro_fifo_enable |
+		st->chip_config.magn_fifo_enable))
 		goto end_session;
 	bytes_per_datum = 0;
 	if (st->chip_config.accl_fifo_enable)
@@ -207,29 +67,55 @@ irqreturn_t inv_mpu6050_read_fifo(int irq, void *p)
 	if (st->chip_config.gyro_fifo_enable)
 		bytes_per_datum += INV_MPU6050_BYTES_PER_3AXIS_SENSOR;
 
+	if (st->chip_config.temp_fifo_enable)
+		bytes_per_datum += INV_MPU6050_BYTES_PER_TEMP_SENSOR;
+
+	if (st->chip_config.magn_fifo_enable)
+		bytes_per_datum += INV_MPU9X50_BYTES_MAGN;
+
 	/*
 	 * read fifo_count register to know how many bytes are inside the FIFO
 	 * right now
 	 */
-	result = regmap_bulk_read(st->map, st->reg->fifo_count_h, data,
-				  INV_MPU6050_FIFO_COUNT_BYTE);
+	result = regmap_bulk_read(st->map, st->reg->fifo_count_h,
+				  st->data, INV_MPU6050_FIFO_COUNT_BYTE);
 	if (result)
 		goto end_session;
-	fifo_count = get_unaligned_be16(&data[0]);
-	/* compute and process all complete datum */
+	fifo_count = be16_to_cpup((__be16 *)&st->data[0]);
+
+	/*
+	 * Handle fifo overflow by resetting fifo.
+	 * Reset if there is only 3 data set free remaining to mitigate
+	 * possible delay between reading fifo count and fifo data.
+	 */
+	nb = 3 * bytes_per_datum;
+	if (fifo_count >= st->hw->fifo_size - nb) {
+		dev_warn(regmap_get_device(st->map), "fifo overflow reset\n");
+		goto flush_fifo;
+	}
+
+	/* compute and process only all complete datum */
 	nb = fifo_count / bytes_per_datum;
-	inv_mpu6050_update_period(st, pf->timestamp, nb);
+	fifo_count = nb * bytes_per_datum;
+	if (nb == 0)
+		goto end_session;
+	/* Each FIFO data contains all sensors, so same number for FIFO and sensor data */
+	fifo_period = NSEC_PER_SEC / INV_MPU6050_DIVIDER_TO_FIFO_RATE(st->chip_config.divider);
+	inv_sensors_timestamp_interrupt(&st->timestamp, 1, pf->timestamp);
+	inv_sensors_timestamp_apply_odr(&st->timestamp, fifo_period, 1, 0);
+
+	/* read all data once and process every samples */
+	result = regmap_noinc_read(st->map, st->reg->fifo_r_w, st->data, fifo_count);
+	if (result)
+		goto flush_fifo;
 	for (i = 0; i < nb; ++i) {
-		result = regmap_bulk_read(st->map, st->reg->fifo_r_w,
-					  data, bytes_per_datum);
-		if (result)
-			goto flush_fifo;
 		/* skip first samples if needed */
 		if (st->skip_samples) {
 			st->skip_samples--;
 			continue;
 		}
-		timestamp = inv_mpu6050_get_timestamp(st);
+		memcpy(data, &st->data[i * bytes_per_datum], bytes_per_datum);
+		timestamp = inv_sensors_timestamp_pop(&st->timestamp);
 		iio_push_to_buffers_with_timestamp(indio_dev, data, timestamp);
 	}