Merge tag 'iio-for-3.9d' of git://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio into staging-next

Jonathan writes:

"4th set of IIO new drivers cleanups and fixes for the 3.9 cycle
+ a new spi helper function.

1) Introduce spi_sync_transfer and use it within IIO.  Originally
   it was envisioned that this nice little boilerplate replacement
   would go through the spi tree, but Grant Likely stated he'd
   prefer we take it through IIO as the example usecases were all
   in IIO (and are also in this pull request).  Note that given
   their may have been some unresolved elements related to the
   coccinelle element of the patch, that has been stripped out
   and will doubtlessly follow at a later date (along with
   lots of other patches for drivers elsewhere in the tree).

2) New Invensense MPU6050 driver.  This is stripped down to pretty
   much the basics from the original submission with the intent
   to build up all the fancy bits in an incremental (and hence
   reviewable fashion). It's been through a good few revisions
   so nice to finally merge this.

3) Change to iio_channel_get api to simplify device tree based
   mappings.  The actual mappings are currently under review.

4) Build fixes for !CONFIG_IIO_TRIGGER in the st_sensors driver.
   This one snuck past during review and testing but got picked
   up by Randy Dunlap in a randconfig build.

5) Some max1363 cleanups and enhancements.

6) Some comment fixes to make them coherent and comprehensible.

7) Trivial build warning fix in mxs-lradc"

1 files changed, 196 insertions, 0 deletions

diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c b/drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c
new file mode 100644
index 0000000..331781f
--- /dev/null
+++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c
@@ -0,0 +1,196 @@
+/*
+* 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>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/i2c.h>
+#include <linux/err.h>
+#include <linux/delay.h>
+#include <linux/sysfs.h>
+#include <linux/jiffies.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+#include <linux/kfifo.h>
+#include <linux/poll.h>
+#include "inv_mpu_iio.h"
+
+int inv_reset_fifo(struct iio_dev *indio_dev)
+{
+	int result;
+	u8 d;
+	struct inv_mpu6050_state  *st = iio_priv(indio_dev);
+
+	/* disable interrupt */
+	result = inv_mpu6050_write_reg(st, st->reg->int_enable, 0);
+	if (result) {
+		dev_err(&st->client->dev, "int_enable failed %d\n", result);
+		return result;
+	}
+	/* disable the sensor output to FIFO */
+	result = inv_mpu6050_write_reg(st, st->reg->fifo_en, 0);
+	if (result)
+		goto reset_fifo_fail;
+	/* disable fifo reading */
+	result = inv_mpu6050_write_reg(st, st->reg->user_ctrl, 0);
+	if (result)
+		goto reset_fifo_fail;
+
+	/* reset FIFO*/
+	result = inv_mpu6050_write_reg(st, st->reg->user_ctrl,
+					INV_MPU6050_BIT_FIFO_RST);
+	if (result)
+		goto reset_fifo_fail;
+	/* enable interrupt */
+	if (st->chip_config.accl_fifo_enable ||
+	    st->chip_config.gyro_fifo_enable) {
+		result = inv_mpu6050_write_reg(st, st->reg->int_enable,
+					INV_MPU6050_BIT_DATA_RDY_EN);
+		if (result)
+			return result;
+	}
+	/* enable FIFO reading and I2C master interface*/
+	result = inv_mpu6050_write_reg(st, st->reg->user_ctrl,
+					INV_MPU6050_BIT_FIFO_EN);
+	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 = inv_mpu6050_write_reg(st, st->reg->fifo_en, d);
+	if (result)
+		goto reset_fifo_fail;
+
+	return 0;
+
+reset_fifo_fail:
+	dev_err(&st->client->dev, "reset fifo failed %d\n", result);
+	result = inv_mpu6050_write_reg(st, st->reg->int_enable,
+					INV_MPU6050_BIT_DATA_RDY_EN);
+
+	return result;
+}
+
+static void inv_clear_kfifo(struct inv_mpu6050_state *st)
+{
+	unsigned long flags;
+
+	/* take the spin lock sem to avoid interrupt kick in */
+	spin_lock_irqsave(&st->time_stamp_lock, flags);
+	kfifo_reset(&st->timestamps);
+	spin_unlock_irqrestore(&st->time_stamp_lock, flags);
+}
+
+/**
+ * inv_mpu6050_irq_handler() - Cache a timestamp at each data ready interrupt.
+ */
+irqreturn_t inv_mpu6050_irq_handler(int irq, void *p)
+{
+	struct iio_poll_func *pf = p;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	struct inv_mpu6050_state *st = iio_priv(indio_dev);
+	s64 timestamp;
+
+	timestamp = iio_get_time_ns();
+	spin_lock(&st->time_stamp_lock);
+	kfifo_in(&st->timestamps, &timestamp, 1);
+	spin_unlock(&st->time_stamp_lock);
+
+	return IRQ_WAKE_THREAD;
+}
+
+/**
+ * inv_mpu6050_read_fifo() - Transfer data from hardware FIFO to KFIFO.
+ */
+irqreturn_t inv_mpu6050_read_fifo(int irq, void *p)
+{
+	struct iio_poll_func *pf = p;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	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;
+	s64 timestamp;
+	u64 *tmp;
+
+	mutex_lock(&indio_dev->mlock);
+	if (!(st->chip_config.accl_fifo_enable |
+		st->chip_config.gyro_fifo_enable))
+		goto end_session;
+	bytes_per_datum = 0;
+	if (st->chip_config.accl_fifo_enable)
+		bytes_per_datum += INV_MPU6050_BYTES_PER_3AXIS_SENSOR;
+
+	if (st->chip_config.gyro_fifo_enable)
+		bytes_per_datum += INV_MPU6050_BYTES_PER_3AXIS_SENSOR;
+
+	/*
+	 * read fifo_count register to know how many bytes inside FIFO
+	 * right now
+	 */
+	result = i2c_smbus_read_i2c_block_data(st->client,
+				       st->reg->fifo_count_h,
+				       INV_MPU6050_FIFO_COUNT_BYTE, data);
+	if (result != INV_MPU6050_FIFO_COUNT_BYTE)
+		goto end_session;
+	fifo_count = be16_to_cpup((__be16 *)(&data[0]));
+	if (fifo_count < bytes_per_datum)
+		goto end_session;
+	/* fifo count can't be odd number, if it is odd, reset fifo*/
+	if (fifo_count & 1)
+		goto flush_fifo;
+	if (fifo_count >  INV_MPU6050_FIFO_THRESHOLD)
+		goto flush_fifo;
+	/* Timestamp mismatch. */
+	if (kfifo_len(&st->timestamps) >
+		fifo_count / bytes_per_datum + INV_MPU6050_TIME_STAMP_TOR)
+			goto flush_fifo;
+	while (fifo_count >= bytes_per_datum) {
+		result = i2c_smbus_read_i2c_block_data(st->client,
+						       st->reg->fifo_r_w,
+						       bytes_per_datum, data);
+		if (result != bytes_per_datum)
+			goto flush_fifo;
+
+		result = kfifo_out(&st->timestamps, &timestamp, 1);
+		/* when there is no timestamp, put timestamp as 0 */
+		if (0 == result)
+			timestamp = 0;
+
+		tmp = (u64 *)data;
+		tmp[DIV_ROUND_UP(bytes_per_datum, 8)] = timestamp;
+		result = iio_push_to_buffers(indio_dev, data);
+		if (result)
+			goto flush_fifo;
+		fifo_count -= bytes_per_datum;
+	}
+
+end_session:
+	mutex_unlock(&indio_dev->mlock);
+	iio_trigger_notify_done(indio_dev->trig);
+
+	return IRQ_HANDLED;
+
+flush_fifo:
+	/* Flush HW and SW FIFOs. */
+	inv_reset_fifo(indio_dev);
+	inv_clear_kfifo(st);
+	mutex_unlock(&indio_dev->mlock);
+	iio_trigger_notify_done(indio_dev->trig);
+
+	return IRQ_HANDLED;
+}