Merge tag 'staging-4.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging

Pull staging and IIO updates from Greg KH:
 "Here is the "big" staging and IIO driver update for 4.15-rc1.

  Lots and lots of little changes, almost all minor code cleanups as the
  Outreachy application process happened during this development cycle.
  Also happened was a lot of IIO driver activity, and the typec USB code
  moving out of staging to drivers/usb (same commits are in the USB tree
  on a persistent branch to not cause merge issues.)

  Overall, it's a wash, I think we added a few hundred more lines than
  removed, but really only a few thousand were modified at all.

  All of these have been in linux-next for a while. There might be a
  merge issue with Al's vfs tree in the pi433 driver (take his changes,
  they are always better), and the media tree with some of the odd
  atomisp cleanups (take the media tree's version)"

* tag 'staging-4.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (507 commits)
  staging: lustre: add SPDX identifiers to all lustre files
  staging: greybus: Remove redundant license text
  staging: greybus: add SPDX identifiers to all greybus driver files
  staging: ccree: simplify ioread/iowrite
  staging: ccree: simplify registers access
  staging: ccree: simplify error handling logic
  staging: ccree: remove dead code
  staging: ccree: handle limiting of DMA masks
  staging: ccree: copy IV to DMAable memory
  staging: fbtft: remove redundant initialization of buf
  staging: sm750fb: Fix parameter mistake in poke32
  staging: wilc1000: Fix bssid buffer offset in Txq
  staging: fbtft: fb_ssd1331: fix mirrored display
  staging: android: Fix checkpatch.pl error
  staging: greybus: loopback: convert loopback to use generic async operations
  staging: greybus: operation: add private data with get/set accessors
  staging: greybus: loopback: Fix iteration count on async path
  staging: greybus: loopback: Hold per-connection mutex across operations
  staging: greybus/loopback: use ktime_get() for time intervals
  staging: fsl-dpaa2/eth: Extra headroom in RX buffers
  ...

1 files changed, 423 insertions, 0 deletions

diff --git a/drivers/iio/accel/cros_ec_accel_legacy.c b/drivers/iio/accel/cros_ec_accel_legacy.c
new file mode 100644
index 000000000000..063e89eff791
--- /dev/null
+++ b/drivers/iio/accel/cros_ec_accel_legacy.c
@@ -0,0 +1,423 @@
+/*
+ * Driver for older Chrome OS EC accelerometer
+ *
+ * Copyright 2017 Google, 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.
+ *
+ * This driver uses the memory mapper cros-ec interface to communicate
+ * with the Chrome OS EC about accelerometer data.
+ * Accelerometer access is presented through iio sysfs.
+ */
+
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/kfifo_buf.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/kernel.h>
+#include <linux/mfd/cros_ec.h>
+#include <linux/mfd/cros_ec_commands.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/sysfs.h>
+#include <linux/platform_device.h>
+
+#define DRV_NAME	"cros-ec-accel-legacy"
+
+/*
+ * Sensor scale hard coded at 10 bits per g, computed as:
+ * g / (2^10 - 1) = 0.009586168; with g = 9.80665 m.s^-2
+ */
+#define ACCEL_LEGACY_NSCALE 9586168
+
+/* Indices for EC sensor values. */
+enum {
+	X,
+	Y,
+	Z,
+	MAX_AXIS,
+};
+
+/* State data for cros_ec_accel_legacy iio driver. */
+struct cros_ec_accel_legacy_state {
+	struct cros_ec_device *ec;
+
+	/*
+	 * Array holding data from a single capture. 2 bytes per channel
+	 * for the 3 channels plus the timestamp which is always last and
+	 * 8-bytes aligned.
+	 */
+	s16 capture_data[8];
+	s8 sign[MAX_AXIS];
+	u8 sensor_num;
+};
+
+static int ec_cmd_read_u8(struct cros_ec_device *ec, unsigned int offset,
+			  u8 *dest)
+{
+	return ec->cmd_readmem(ec, offset, 1, dest);
+}
+
+static int ec_cmd_read_u16(struct cros_ec_device *ec, unsigned int offset,
+			   u16 *dest)
+{
+	__le16 tmp;
+	int ret = ec->cmd_readmem(ec, offset, 2, &tmp);
+
+	*dest = le16_to_cpu(tmp);
+
+	return ret;
+}
+
+/**
+ * read_ec_until_not_busy() - Read from EC status byte until it reads not busy.
+ * @st: Pointer to state information for device.
+ *
+ * This function reads EC status until its busy bit gets cleared. It does not
+ * wait indefinitely and returns -EIO if the EC status is still busy after a
+ * few hundreds milliseconds.
+ *
+ * Return: 8-bit status if ok, -EIO on error
+ */
+static int read_ec_until_not_busy(struct cros_ec_accel_legacy_state *st)
+{
+	struct cros_ec_device *ec = st->ec;
+	u8 status;
+	int attempts = 0;
+
+	ec_cmd_read_u8(ec, EC_MEMMAP_ACC_STATUS, &status);
+	while (status & EC_MEMMAP_ACC_STATUS_BUSY_BIT) {
+		/* Give up after enough attempts, return error. */
+		if (attempts++ >= 50)
+			return -EIO;
+
+		/* Small delay every so often. */
+		if (attempts % 5 == 0)
+			msleep(25);
+
+		ec_cmd_read_u8(ec, EC_MEMMAP_ACC_STATUS, &status);
+	}
+
+	return status;
+}
+
+/**
+ * read_ec_accel_data_unsafe() - Read acceleration data from EC shared memory.
+ * @st:        Pointer to state information for device.
+ * @scan_mask: Bitmap of the sensor indices to scan.
+ * @data:      Location to store data.
+ *
+ * This is the unsafe function for reading the EC data. It does not guarantee
+ * that the EC will not modify the data as it is being read in.
+ */
+static void read_ec_accel_data_unsafe(struct cros_ec_accel_legacy_state *st,
+				      unsigned long scan_mask, s16 *data)
+{
+	int i = 0;
+	int num_enabled = bitmap_weight(&scan_mask, MAX_AXIS);
+
+	/* Read all sensors enabled in scan_mask. Each value is 2 bytes. */
+	while (num_enabled--) {
+		i = find_next_bit(&scan_mask, MAX_AXIS, i);
+		ec_cmd_read_u16(st->ec,
+				EC_MEMMAP_ACC_DATA +
+				sizeof(s16) *
+				(1 + i + st->sensor_num * MAX_AXIS),
+				data);
+		*data *= st->sign[i];
+		i++;
+		data++;
+	}
+}
+
+/**
+ * read_ec_accel_data() - Read acceleration data from EC shared memory.
+ * @st:        Pointer to state information for device.
+ * @scan_mask: Bitmap of the sensor indices to scan.
+ * @data:      Location to store data.
+ *
+ * This is the safe function for reading the EC data. It guarantees that
+ * the data sampled was not modified by the EC while being read.
+ *
+ * Return: 0 if ok, -ve on error
+ */
+static int read_ec_accel_data(struct cros_ec_accel_legacy_state *st,
+			      unsigned long scan_mask, s16 *data)
+{
+	u8 samp_id = 0xff;
+	u8 status = 0;
+	int ret;
+	int attempts = 0;
+
+	/*
+	 * Continually read all data from EC until the status byte after
+	 * all reads reflects that the EC is not busy and the sample id
+	 * matches the sample id from before all reads. This guarantees
+	 * that data read in was not modified by the EC while reading.
+	 */
+	while ((status & (EC_MEMMAP_ACC_STATUS_BUSY_BIT |
+			  EC_MEMMAP_ACC_STATUS_SAMPLE_ID_MASK)) != samp_id) {
+		/* If we have tried to read too many times, return error. */
+		if (attempts++ >= 5)
+			return -EIO;
+
+		/* Read status byte until EC is not busy. */
+		ret = read_ec_until_not_busy(st);
+		if (ret < 0)
+			return ret;
+		status = ret;
+
+		/*
+		 * Store the current sample id so that we can compare to the
+		 * sample id after reading the data.
+		 */
+		samp_id = status & EC_MEMMAP_ACC_STATUS_SAMPLE_ID_MASK;
+
+		/* Read all EC data, format it, and store it into data. */
+		read_ec_accel_data_unsafe(st, scan_mask, data);
+
+		/* Read status byte. */
+		ec_cmd_read_u8(st->ec, EC_MEMMAP_ACC_STATUS, &status);
+	}
+
+	return 0;
+}
+
+static int cros_ec_accel_legacy_read(struct iio_dev *indio_dev,
+				     struct iio_chan_spec const *chan,
+				     int *val, int *val2, long mask)
+{
+	struct cros_ec_accel_legacy_state *st = iio_priv(indio_dev);
+	s16 data = 0;
+	int ret = IIO_VAL_INT;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		ret = read_ec_accel_data(st, (1 << chan->scan_index), &data);
+		if (ret)
+			return ret;
+		*val = data;
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_SCALE:
+		*val = 0;
+		*val2 = ACCEL_LEGACY_NSCALE;
+		return IIO_VAL_INT_PLUS_NANO;
+	case IIO_CHAN_INFO_CALIBBIAS:
+		/* Calibration not supported. */
+		*val = 0;
+		return IIO_VAL_INT;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int cros_ec_accel_legacy_write(struct iio_dev *indio_dev,
+				      struct iio_chan_spec const *chan,
+				      int val, int val2, long mask)
+{
+	/*
+	 * Do nothing but don't return an error code to allow calibration
+	 * script to work.
+	 */
+	if (mask == IIO_CHAN_INFO_CALIBBIAS)
+		return 0;
+
+	return -EINVAL;
+}
+
+static const struct iio_info cros_ec_accel_legacy_info = {
+	.read_raw = &cros_ec_accel_legacy_read,
+	.write_raw = &cros_ec_accel_legacy_write,
+};
+
+/**
+ * cros_ec_accel_legacy_capture() - The trigger handler function
+ * @irq: The interrupt number.
+ * @p:   Private data - always a pointer to the poll func.
+ *
+ * On a trigger event occurring, if the pollfunc is attached then this
+ * handler is called as a threaded interrupt (and hence may sleep). It
+ * is responsible for grabbing data from the device and pushing it into
+ * the associated buffer.
+ *
+ * Return: IRQ_HANDLED
+ */
+static irqreturn_t cros_ec_accel_legacy_capture(int irq, void *p)
+{
+	struct iio_poll_func *pf = p;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	struct cros_ec_accel_legacy_state *st = iio_priv(indio_dev);
+
+	/* Clear capture data. */
+	memset(st->capture_data, 0, sizeof(st->capture_data));
+
+	/*
+	 * Read data based on which channels are enabled in scan mask. Note
+	 * that on a capture we are always reading the calibrated data.
+	 */
+	read_ec_accel_data(st, *indio_dev->active_scan_mask, st->capture_data);
+
+	iio_push_to_buffers_with_timestamp(indio_dev, (void *)st->capture_data,
+					   iio_get_time_ns(indio_dev));
+
+	/*
+	 * Tell the core we are done with this trigger and ready for the
+	 * next one.
+	 */
+	iio_trigger_notify_done(indio_dev->trig);
+
+	return IRQ_HANDLED;
+}
+
+static char *cros_ec_accel_legacy_loc_strings[] = {
+	[MOTIONSENSE_LOC_BASE] = "base",
+	[MOTIONSENSE_LOC_LID] = "lid",
+	[MOTIONSENSE_LOC_MAX] = "unknown",
+};
+
+static ssize_t cros_ec_accel_legacy_loc(struct iio_dev *indio_dev,
+					uintptr_t private,
+					const struct iio_chan_spec *chan,
+					char *buf)
+{
+	struct cros_ec_accel_legacy_state *st = iio_priv(indio_dev);
+
+	return sprintf(buf, "%s\n",
+		       cros_ec_accel_legacy_loc_strings[st->sensor_num +
+							MOTIONSENSE_LOC_BASE]);
+}
+
+static ssize_t cros_ec_accel_legacy_id(struct iio_dev *indio_dev,
+				       uintptr_t private,
+				       const struct iio_chan_spec *chan,
+				       char *buf)
+{
+	struct cros_ec_accel_legacy_state *st = iio_priv(indio_dev);
+
+	return sprintf(buf, "%d\n", st->sensor_num);
+}
+
+static const struct iio_chan_spec_ext_info cros_ec_accel_legacy_ext_info[] = {
+	{
+		.name = "id",
+		.shared = IIO_SHARED_BY_ALL,
+		.read = cros_ec_accel_legacy_id,
+	},
+	{
+		.name = "location",
+		.shared = IIO_SHARED_BY_ALL,
+		.read = cros_ec_accel_legacy_loc,
+	},
+	{ }
+};
+
+#define CROS_EC_ACCEL_LEGACY_CHAN(_axis)				\
+	{								\
+		.type = IIO_ACCEL,					\
+		.channel2 = IIO_MOD_X + (_axis),			\
+		.modified = 1,					        \
+		.info_mask_separate =					\
+			BIT(IIO_CHAN_INFO_RAW) |			\
+			BIT(IIO_CHAN_INFO_SCALE) |			\
+			BIT(IIO_CHAN_INFO_CALIBBIAS),			\
+		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SCALE),	\
+		.ext_info = cros_ec_accel_legacy_ext_info,		\
+		.scan_type = {						\
+			.sign = 's',					\
+			.realbits = 16,					\
+			.storagebits = 16,				\
+		},							\
+	}								\
+
+static struct iio_chan_spec ec_accel_channels[] = {
+	CROS_EC_ACCEL_LEGACY_CHAN(X),
+	CROS_EC_ACCEL_LEGACY_CHAN(Y),
+	CROS_EC_ACCEL_LEGACY_CHAN(Z),
+	IIO_CHAN_SOFT_TIMESTAMP(MAX_AXIS)
+};
+
+static int cros_ec_accel_legacy_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct cros_ec_dev *ec = dev_get_drvdata(dev->parent);
+	struct cros_ec_sensor_platform *sensor_platform = dev_get_platdata(dev);
+	struct iio_dev *indio_dev;
+	struct cros_ec_accel_legacy_state *state;
+	int ret, i;
+
+	if (!ec || !ec->ec_dev) {
+		dev_warn(&pdev->dev, "No EC device found.\n");
+		return -EINVAL;
+	}
+
+	if (!ec->ec_dev->cmd_readmem) {
+		dev_warn(&pdev->dev, "EC does not support direct reads.\n");
+		return -EINVAL;
+	}
+
+	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*state));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, indio_dev);
+	state = iio_priv(indio_dev);
+	state->ec = ec->ec_dev;
+	state->sensor_num = sensor_platform->sensor_num;
+
+	indio_dev->dev.parent = dev;
+	indio_dev->name = pdev->name;
+	indio_dev->channels = ec_accel_channels;
+	/*
+	 * Present the channel using HTML5 standard:
+	 * need to invert X and Y and invert some lid axis.
+	 */
+	for (i = X ; i < MAX_AXIS; i++) {
+		switch (i) {
+		case X:
+			ec_accel_channels[X].scan_index = Y;
+		case Y:
+			ec_accel_channels[Y].scan_index = X;
+		case Z:
+			ec_accel_channels[Z].scan_index = Z;
+		}
+		if (state->sensor_num == MOTIONSENSE_LOC_LID && i != Y)
+			state->sign[i] = -1;
+		else
+			state->sign[i] = 1;
+	}
+	indio_dev->num_channels = ARRAY_SIZE(ec_accel_channels);
+	indio_dev->dev.parent = &pdev->dev;
+	indio_dev->info = &cros_ec_accel_legacy_info;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+
+	ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL,
+					      cros_ec_accel_legacy_capture,
+					      NULL);
+	if (ret)
+		return ret;
+
+	return devm_iio_device_register(dev, indio_dev);
+}
+
+static struct platform_driver cros_ec_accel_platform_driver = {
+	.driver = {
+		.name	= DRV_NAME,
+	},
+	.probe		= cros_ec_accel_legacy_probe,
+};
+module_platform_driver(cros_ec_accel_platform_driver);
+
+MODULE_DESCRIPTION("ChromeOS EC legacy accelerometer driver");
+MODULE_AUTHOR("Gwendal Grignou <gwendal@chromium.org>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:" DRV_NAME);