1 files changed, 329 insertions, 0 deletions

diff --git a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c
new file mode 100644
index 000000000..66153b185
--- /dev/null
+++ b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c
@@ -0,0 +1,329 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * cros_ec_sensors - Driver for Chrome OS Embedded Controller sensors.
+ *
+ * Copyright (C) 2016 Google, Inc
+ *
+ * This driver uses the cros-ec interface to communicate with the Chrome OS
+ * EC about sensors data. Data access is presented through iio sysfs.
+ */
+
+#include <linux/device.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/common/cros_ec_sensors_core.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/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/platform_data/cros_ec_commands.h>
+#include <linux/platform_data/cros_ec_proto.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#define CROS_EC_SENSORS_MAX_CHANNELS 4
+
+/* State data for ec_sensors iio driver. */
+struct cros_ec_sensors_state {
+	/* Shared by all sensors */
+	struct cros_ec_sensors_core_state core;
+
+	struct iio_chan_spec channels[CROS_EC_SENSORS_MAX_CHANNELS];
+};
+
+static int cros_ec_sensors_read(struct iio_dev *indio_dev,
+			  struct iio_chan_spec const *chan,
+			  int *val, int *val2, long mask)
+{
+	struct cros_ec_sensors_state *st = iio_priv(indio_dev);
+	s16 data = 0;
+	s64 val64;
+	int i;
+	int ret;
+	int idx = chan->scan_index;
+
+	mutex_lock(&st->core.cmd_lock);
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		ret = st->core.read_ec_sensors_data(indio_dev, 1 << idx, &data);
+		if (ret < 0)
+			break;
+		ret = IIO_VAL_INT;
+		*val = data;
+		break;
+	case IIO_CHAN_INFO_CALIBBIAS:
+		st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_OFFSET;
+		st->core.param.sensor_offset.flags = 0;
+
+		ret = cros_ec_motion_send_host_cmd(&st->core, 0);
+		if (ret < 0)
+			break;
+
+		/* Save values */
+		for (i = CROS_EC_SENSOR_X; i < CROS_EC_SENSOR_MAX_AXIS; i++)
+			st->core.calib[i].offset =
+				st->core.resp->sensor_offset.offset[i];
+		ret = IIO_VAL_INT;
+		*val = st->core.calib[idx].offset;
+		break;
+	case IIO_CHAN_INFO_CALIBSCALE:
+		st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_SCALE;
+		st->core.param.sensor_offset.flags = 0;
+
+		ret = cros_ec_motion_send_host_cmd(&st->core, 0);
+		if (ret == -EPROTO || ret == -EOPNOTSUPP) {
+			/* Reading calibscale is not supported on older EC. */
+			*val = 1;
+			*val2 = 0;
+			ret = IIO_VAL_INT_PLUS_MICRO;
+			break;
+		} else if (ret) {
+			break;
+		}
+
+		/* Save values */
+		for (i = CROS_EC_SENSOR_X; i < CROS_EC_SENSOR_MAX_AXIS; i++)
+			st->core.calib[i].scale =
+				st->core.resp->sensor_scale.scale[i];
+
+		*val = st->core.calib[idx].scale >> 15;
+		*val2 = ((st->core.calib[idx].scale & 0x7FFF) * 1000000LL) /
+			MOTION_SENSE_DEFAULT_SCALE;
+		ret = IIO_VAL_INT_PLUS_MICRO;
+		break;
+	case IIO_CHAN_INFO_SCALE:
+		st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_RANGE;
+		st->core.param.sensor_range.data = EC_MOTION_SENSE_NO_VALUE;
+
+		ret = cros_ec_motion_send_host_cmd(&st->core, 0);
+		if (ret < 0)
+			break;
+
+		val64 = st->core.resp->sensor_range.ret;
+		switch (st->core.type) {
+		case MOTIONSENSE_TYPE_ACCEL:
+			/*
+			 * EC returns data in g, iio exepects m/s^2.
+			 * Do not use IIO_G_TO_M_S_2 to avoid precision loss.
+			 */
+			*val = div_s64(val64 * 980665, 10);
+			*val2 = 10000 << (CROS_EC_SENSOR_BITS - 1);
+			ret = IIO_VAL_FRACTIONAL;
+			break;
+		case MOTIONSENSE_TYPE_GYRO:
+			/*
+			 * EC returns data in dps, iio expects rad/s.
+			 * Do not use IIO_DEGREE_TO_RAD to avoid precision
+			 * loss. Round to the nearest integer.
+			 */
+			*val = 0;
+			*val2 = div_s64(val64 * 3141592653ULL,
+					180 << (CROS_EC_SENSOR_BITS - 1));
+			ret = IIO_VAL_INT_PLUS_NANO;
+			break;
+		case MOTIONSENSE_TYPE_MAG:
+			/*
+			 * EC returns data in 16LSB / uT,
+			 * iio expects Gauss
+			 */
+			*val = val64;
+			*val2 = 100 << (CROS_EC_SENSOR_BITS - 1);
+			ret = IIO_VAL_FRACTIONAL;
+			break;
+		default:
+			ret = -EINVAL;
+		}
+		break;
+	default:
+		ret = cros_ec_sensors_core_read(&st->core, chan, val, val2,
+						mask);
+		break;
+	}
+	mutex_unlock(&st->core.cmd_lock);
+
+	return ret;
+}
+
+static int cros_ec_sensors_write(struct iio_dev *indio_dev,
+			       struct iio_chan_spec const *chan,
+			       int val, int val2, long mask)
+{
+	struct cros_ec_sensors_state *st = iio_priv(indio_dev);
+	int i;
+	int ret;
+	int idx = chan->scan_index;
+
+	mutex_lock(&st->core.cmd_lock);
+
+	switch (mask) {
+	case IIO_CHAN_INFO_CALIBBIAS:
+		st->core.calib[idx].offset = val;
+
+		/* Send to EC for each axis, even if not complete */
+		st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_OFFSET;
+		st->core.param.sensor_offset.flags =
+			MOTION_SENSE_SET_OFFSET;
+		for (i = CROS_EC_SENSOR_X; i < CROS_EC_SENSOR_MAX_AXIS; i++)
+			st->core.param.sensor_offset.offset[i] =
+				st->core.calib[i].offset;
+		st->core.param.sensor_offset.temp =
+			EC_MOTION_SENSE_INVALID_CALIB_TEMP;
+
+		ret = cros_ec_motion_send_host_cmd(&st->core, 0);
+		break;
+	case IIO_CHAN_INFO_CALIBSCALE:
+		st->core.calib[idx].scale = val;
+		/* Send to EC for each axis, even if not complete */
+
+		st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_SCALE;
+		st->core.param.sensor_offset.flags =
+			MOTION_SENSE_SET_OFFSET;
+		for (i = CROS_EC_SENSOR_X; i < CROS_EC_SENSOR_MAX_AXIS; i++)
+			st->core.param.sensor_scale.scale[i] =
+				st->core.calib[i].scale;
+		st->core.param.sensor_scale.temp =
+			EC_MOTION_SENSE_INVALID_CALIB_TEMP;
+
+		ret = cros_ec_motion_send_host_cmd(&st->core, 0);
+		break;
+	case IIO_CHAN_INFO_SCALE:
+		if (st->core.type == MOTIONSENSE_TYPE_MAG) {
+			ret = -EINVAL;
+			break;
+		}
+		st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_RANGE;
+		st->core.param.sensor_range.data = val;
+
+		/* Always roundup, so caller gets at least what it asks for. */
+		st->core.param.sensor_range.roundup = 1;
+
+		ret = cros_ec_motion_send_host_cmd(&st->core, 0);
+		if (ret == 0) {
+			st->core.range_updated = true;
+			st->core.curr_range = val;
+		}
+		break;
+	default:
+		ret = cros_ec_sensors_core_write(
+				&st->core, chan, val, val2, mask);
+		break;
+	}
+
+	mutex_unlock(&st->core.cmd_lock);
+
+	return ret;
+}
+
+static const struct iio_info ec_sensors_info = {
+	.read_raw = &cros_ec_sensors_read,
+	.write_raw = &cros_ec_sensors_write,
+	.read_avail = &cros_ec_sensors_core_read_avail,
+};
+
+static int cros_ec_sensors_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct iio_dev *indio_dev;
+	struct cros_ec_sensors_state *state;
+	struct iio_chan_spec *channel;
+	int ret, i;
+
+	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*state));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	ret = cros_ec_sensors_core_init(pdev, indio_dev, true,
+					cros_ec_sensors_capture);
+	if (ret)
+		return ret;
+
+	indio_dev->info = &ec_sensors_info;
+	state = iio_priv(indio_dev);
+	for (channel = state->channels, i = CROS_EC_SENSOR_X;
+	     i < CROS_EC_SENSOR_MAX_AXIS; i++, channel++) {
+		/* Common part */
+		channel->info_mask_separate =
+			BIT(IIO_CHAN_INFO_RAW) |
+			BIT(IIO_CHAN_INFO_CALIBBIAS) |
+			BIT(IIO_CHAN_INFO_CALIBSCALE);
+		channel->info_mask_shared_by_all =
+			BIT(IIO_CHAN_INFO_SCALE) |
+			BIT(IIO_CHAN_INFO_SAMP_FREQ);
+		channel->info_mask_shared_by_all_available =
+			BIT(IIO_CHAN_INFO_SAMP_FREQ);
+		channel->scan_type.realbits = CROS_EC_SENSOR_BITS;
+		channel->scan_type.storagebits = CROS_EC_SENSOR_BITS;
+		channel->scan_index = i;
+		channel->ext_info = cros_ec_sensors_ext_info;
+		channel->modified = 1;
+		channel->channel2 = IIO_MOD_X + i;
+		channel->scan_type.sign = 's';
+
+		/* Sensor specific */
+		switch (state->core.type) {
+		case MOTIONSENSE_TYPE_ACCEL:
+			channel->type = IIO_ACCEL;
+			break;
+		case MOTIONSENSE_TYPE_GYRO:
+			channel->type = IIO_ANGL_VEL;
+			break;
+		case MOTIONSENSE_TYPE_MAG:
+			channel->type = IIO_MAGN;
+			break;
+		default:
+			dev_err(&pdev->dev, "Unknown motion sensor\n");
+			return -EINVAL;
+		}
+	}
+
+	/* Timestamp */
+	channel->type = IIO_TIMESTAMP;
+	channel->channel = -1;
+	channel->scan_index = CROS_EC_SENSOR_MAX_AXIS;
+	channel->scan_type.sign = 's';
+	channel->scan_type.realbits = 64;
+	channel->scan_type.storagebits = 64;
+
+	indio_dev->channels = state->channels;
+	indio_dev->num_channels = CROS_EC_SENSORS_MAX_CHANNELS;
+
+	/* There is only enough room for accel and gyro in the io space */
+	if ((state->core.ec->cmd_readmem != NULL) &&
+	    (state->core.type != MOTIONSENSE_TYPE_MAG))
+		state->core.read_ec_sensors_data = cros_ec_sensors_read_lpc;
+	else
+		state->core.read_ec_sensors_data = cros_ec_sensors_read_cmd;
+
+	return cros_ec_sensors_core_register(dev, indio_dev,
+			cros_ec_sensors_push_data);
+}
+
+static const struct platform_device_id cros_ec_sensors_ids[] = {
+	{
+		.name = "cros-ec-accel",
+	},
+	{
+		.name = "cros-ec-gyro",
+	},
+	{
+		.name = "cros-ec-mag",
+	},
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(platform, cros_ec_sensors_ids);
+
+static struct platform_driver cros_ec_sensors_platform_driver = {
+	.driver = {
+		.name	= "cros-ec-sensors",
+		.pm	= &cros_ec_sensors_pm_ops,
+	},
+	.probe		= cros_ec_sensors_probe,
+	.id_table	= cros_ec_sensors_ids,
+};
+module_platform_driver(cros_ec_sensors_platform_driver);
+
+MODULE_DESCRIPTION("ChromeOS EC 3-axis sensors driver");
+MODULE_LICENSE("GPL v2");