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SubjectRe: [PATCH v3 1/4] iio: cros_ec_sensors_core: Add common functions for the ChromeOS EC Sensor Hub.
On Thu, Jul 28, 2016 at 6:49 AM, Enric Balletbo i Serra
<enric.balletbo@collabora.com> wrote:
> Add the core functions to be able to support the sensors attached behind
> the ChromeOS Embedded Controller and used by other IIO cros-ec sensor
> drivers.
>
> The cros_ec_sensor_core driver matches with current driver in ChromeOS
> 4.4 tree, so it includes all the fixes at the moment. The support for
> this driver was made by Gwendal Grignou. The original patch and all the
> fixes has been squashed and rebased on top of mainline.
>
> Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
> Signed-off-by: Guenter Roeck <groeck@chromium.org>
> [eballetbo: split, squash and rebase on top of mainline the patches
> found in ChromeOS tree]
> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
> ---
>
> Changes since v2:
> - Rebased and fix build error.
> - Include a list of possible values in the description of location attr.
> - Fix some typos.
> - Remove id sysfs entry.
>
> Changes since v1:
> - Check kernel-doc documentation.
> - Bring this in as an when you need it in the rest of the series.
> - Fix some spelling mistakes.
> - Include ABI documentation.
> - Be more careful with buffer sizes (sprintf -> snprintf)
> - Add cros_ec_sensors prefix to all function.
> - Check return values on some functions.
>
>
> Documentation/ABI/testing/sysfs-bus-iio-cros-ec | 18 +
> drivers/iio/common/Kconfig | 1 +
> drivers/iio/common/Makefile | 1 +
> drivers/iio/common/cros_ec_sensors/Kconfig | 14 +
> drivers/iio/common/cros_ec_sensors/Makefile | 5 +
> .../common/cros_ec_sensors/cros_ec_sensors_core.c | 491 +++++++++++++++++++++
> .../common/cros_ec_sensors/cros_ec_sensors_core.h | 177 ++++++++
> include/linux/mfd/cros_ec.h | 9 +
> include/linux/mfd/cros_ec_commands.h | 99 ++++-
> 9 files changed, 810 insertions(+), 5 deletions(-)
> create mode 100644 Documentation/ABI/testing/sysfs-bus-iio-cros-ec
> create mode 100644 drivers/iio/common/cros_ec_sensors/Kconfig
> create mode 100644 drivers/iio/common/cros_ec_sensors/Makefile
> create mode 100644 drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
> create mode 100644 drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.h
>
> diff --git a/Documentation/ABI/testing/sysfs-bus-iio-cros-ec b/Documentation/ABI/testing/sysfs-bus-iio-cros-ec
> new file mode 100644
> index 0000000..297b972
> --- /dev/null
> +++ b/Documentation/ABI/testing/sysfs-bus-iio-cros-ec
> @@ -0,0 +1,18 @@
> +What: /sys/bus/iio/devices/iio:deviceX/calibrate
> +Date: July 2015
> +KernelVersion: 4.7
> +Contact: linux-iio@vger.kernel.org
> +Description:
> + Writing '1' will perform a FOC (Fast Online Calibration). The
> + corresponding calibration offsets can be read from *_calibbias
> + entries.
> +
> +What: /sys/bus/iio/devices/iio:deviceX/location
> +Date: July 2015
> +KernelVersion: 4.7
> +Contact: linux-iio@vger.kernel.org
> +Description:
> + This attribute returns a string with the physical location where
> + the motion sensor is placed. For example, in a laptop a motion
> + sensor can be located on the base or on the lid. Current valid
> + values are 'base' and 'lid'.
> diff --git a/drivers/iio/common/Kconfig b/drivers/iio/common/Kconfig
> index 26a6026..e108996 100644
> --- a/drivers/iio/common/Kconfig
> +++ b/drivers/iio/common/Kconfig
> @@ -2,6 +2,7 @@
> # IIO common modules
> #
>
> +source "drivers/iio/common/cros_ec_sensors/Kconfig"
> source "drivers/iio/common/hid-sensors/Kconfig"
> source "drivers/iio/common/ms_sensors/Kconfig"
> source "drivers/iio/common/ssp_sensors/Kconfig"
> diff --git a/drivers/iio/common/Makefile b/drivers/iio/common/Makefile
> index 585da6a..6fa760e 100644
> --- a/drivers/iio/common/Makefile
> +++ b/drivers/iio/common/Makefile
> @@ -7,6 +7,7 @@
> #
>
> # When adding new entries keep the list in alphabetical order
> +obj-y += cros_ec_sensors/
> obj-y += hid-sensors/
> obj-y += ms_sensors/
> obj-y += ssp_sensors/
> diff --git a/drivers/iio/common/cros_ec_sensors/Kconfig b/drivers/iio/common/cros_ec_sensors/Kconfig
> new file mode 100644
> index 0000000..24743be
> --- /dev/null
> +++ b/drivers/iio/common/cros_ec_sensors/Kconfig
> @@ -0,0 +1,14 @@
> +#
> +# Chrome OS Embedded Controller managed sensors library
> +#
> +config IIO_CROS_EC_SENSORS_CORE
> + tristate "ChromeOS EC Sensors Core"
> + depends on SYSFS && MFD_CROS_EC
> + select IIO_BUFFER
> + select IIO_TRIGGERED_BUFFER
> + help
> + Base module for the ChromeOS EC Sensors module.
> + Contains core functions used by other IIO CrosEC sensor
> + drivers.
> + Define common attributes and sysfs interrupt handler.
> +
> diff --git a/drivers/iio/common/cros_ec_sensors/Makefile b/drivers/iio/common/cros_ec_sensors/Makefile
> new file mode 100644
> index 0000000..95b6901
> --- /dev/null
> +++ b/drivers/iio/common/cros_ec_sensors/Makefile
> @@ -0,0 +1,5 @@
> +#
> +# Makefile for sensors seen through the ChromeOS EC sensor hub.
> +#
> +
> +obj-$(CONFIG_IIO_CROS_EC_SENSORS_CORE) += cros_ec_sensors_core.o
> diff --git a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
> new file mode 100644
> index 0000000..acc87b3
> --- /dev/null
> +++ b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
> @@ -0,0 +1,491 @@
> +/*
> + * cros_ec_sensors_core - Common function for Chrome OS EC sensor driver.
> + *
> + * Copyright (C) 2016 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.
> + */
> +
> +#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/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>
> +
> +#include "cros_ec_sensors_core.h"
> +
> +static char *cros_ec_loc[] = {
> + [MOTIONSENSE_LOC_BASE] = "base",
> + [MOTIONSENSE_LOC_LID] = "lid",
> + [MOTIONSENSE_LOC_MAX] = "unknown",
> +};
> +
> +int cros_ec_sensors_core_init(struct platform_device *pdev,
> + struct iio_dev *indio_dev,
> + bool physical_device)
> +{
> + struct device *dev = &pdev->dev;
> + struct cros_ec_sensors_core_state *state = iio_priv(indio_dev);
> + struct cros_ec_dev *ec = dev_get_drvdata(pdev->dev.parent);
> + struct cros_ec_sensor_platform *sensor_platform = dev_get_platdata(dev);
> +
> + platform_set_drvdata(pdev, indio_dev);
> +
> + state->ec = ec->ec_dev;
> + state->msg = devm_kzalloc(&pdev->dev,
> + max((u16)sizeof(struct ec_params_motion_sense),
> + state->ec->max_response), GFP_KERNEL);
> + if (!state->msg)
> + return -ENOMEM;
> +
> + state->resp = (struct ec_response_motion_sense *)state->msg->data;
> +
> + mutex_init(&state->cmd_lock);
> +
> + /* Set up the host command structure. */
> + state->msg->version = 2;
> + state->msg->command = EC_CMD_MOTION_SENSE_CMD + ec->cmd_offset;
> + state->msg->outsize = sizeof(struct ec_params_motion_sense);
> +
> + indio_dev->dev.parent = &pdev->dev;
> + indio_dev->name = pdev->name;
> +
> + if (physical_device) {
> + indio_dev->modes = INDIO_DIRECT_MODE;
> +
> + state->param.cmd = MOTIONSENSE_CMD_INFO;
> + state->param.info.sensor_num = sensor_platform->sensor_num;
> + if (cros_ec_motion_send_host_cmd(state, 0)) {
> + dev_warn(dev, "Can not access sensor info\n");
> + return -EIO;
> + }
> + state->type = state->resp->info.type;
> + state->loc = state->resp->info.location;
> + }
> +
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(cros_ec_sensors_core_init);
> +
> +int cros_ec_motion_send_host_cmd(struct cros_ec_sensors_core_state *state,
> + u16 opt_length)
> +{
> + int ret;
> +
> + if (opt_length)
> + state->msg->insize = min(opt_length, state->ec->max_response);
> + else
> + state->msg->insize = state->ec->max_response;
> +
> + memcpy(state->msg->data, &state->param, sizeof(state->param));
> +
> + ret = cros_ec_cmd_xfer_status(state->ec, state->msg);
> + if (ret < 0)
> + return -EIO;
> +
> + if (ret &&
> + state->resp != (struct ec_response_motion_sense *)state->msg->data)
> + memcpy(state->resp, state->msg->data, ret);
> +
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(cros_ec_motion_send_host_cmd);
> +
> +static ssize_t cros_ec_sensors_calibrate(struct iio_dev *indio_dev,
> + uintptr_t private, const struct iio_chan_spec *chan,
> + const char *buf, size_t len)
> +{
> + struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
> + int ret, i;
> + bool calibrate;
> +
> + ret = strtobool(buf, &calibrate);
> + if (ret < 0)
> + return ret;
> + if (!calibrate)
> + return -EINVAL;
> +
> + mutex_lock(&st->cmd_lock);
> + st->param.cmd = MOTIONSENSE_CMD_PERFORM_CALIB;
> + ret = cros_ec_motion_send_host_cmd(st, 0);
> + if (ret != 0) {
> + dev_warn(&indio_dev->dev, "Unable to calibrate sensor\n");
> + } else {
> + /* Save values */
> + for (i = CROS_EC_SENSOR_X; i < CROS_EC_SENSOR_MAX_AXIS; i++)
> + st->calib[i].offset = st->resp->perform_calib.offset[i];
> + }
> + mutex_unlock(&st->cmd_lock);
> +
> + return ret ? ret : len;
> +}
> +
> +static ssize_t cros_ec_sensors_loc(struct iio_dev *indio_dev,
> + uintptr_t private, const struct iio_chan_spec *chan,
> + char *buf)
> +{
> + struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
> +
> + return snprintf(buf, PAGE_SIZE, "%s\n", cros_ec_loc[st->loc]);
> +}
> +
> +const struct iio_chan_spec_ext_info cros_ec_sensors_ext_info[] = {
> + {
> + .name = "calibrate",
> + .shared = IIO_SHARED_BY_ALL,
> + .write = cros_ec_sensors_calibrate
> + },
> + {
> + .name = "location",
> + .shared = IIO_SHARED_BY_ALL,
> + .read = cros_ec_sensors_loc
> + },
> + { },
> +};
> +EXPORT_SYMBOL_GPL(cros_ec_sensors_ext_info);
> +
> +/**
> + * cros_ec_sensors_idx_to_reg - convert index into offset in shared memory
> + * @st: pointer to state information for device
> + * @idx: sensor index (should be element of enum sensor_index)
> + *
> + * Return: address to read at
> + */
> +static unsigned int cros_ec_sensors_idx_to_reg(
> + struct cros_ec_sensors_core_state *st,
> + unsigned int idx)
> +{
> + /*
> + * When using LPC interface, only space for 2 Accel and one Gyro.
> + * First halfword of MOTIONSENSE_TYPE_ACCEL is used by angle.
> + */
> + if (st->type == MOTIONSENSE_TYPE_ACCEL)
> + return EC_MEMMAP_ACC_DATA + sizeof(u16) *
> + (1 + idx + st->param.info.sensor_num *
> + CROS_EC_SENSOR_MAX_AXIS);
> + else

Nitpick: Unnecessary else

> + return EC_MEMMAP_GYRO_DATA + sizeof(u16) * idx;
> +}
> +
> +static int cros_ec_sensors_cmd_read_u8(struct cros_ec_device *ec,
> + unsigned int offset, u8 *dest)
> +{
> + return ec->cmd_readmem(ec, offset, 1, dest);
> +}
> +
> +static int cros_ec_sensors_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);
> +

I am a bit concerned here about "variable may be unused" messages from
the compiler. Not that it really matters, but maybe the conversion
should only be done if ret >= 0.

> + return ret;
> +}
> +
> +/**
> + * cros_ec_sensors_read_until_not_busy() - read until is not busy
> + *
> + * @st: pointer to state information for device
> + *
> + * Read from EC status byte until it reads not busy.
> + * Return: 8-bit status if ok, -errno on failure.
> + */
> +static int cros_ec_sensors_read_until_not_busy(
> + struct cros_ec_sensors_core_state *st)
> +{
> + struct cros_ec_device *ec = st->ec;
> + u8 status;
> + int ret, attempts = 0;
> +
> + ret = cros_ec_sensors_cmd_read_u8(ec, EC_MEMMAP_ACC_STATUS, &status);
> + if (ret < 0)
> + return ret;
> +
> + 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);
> +
> + ret = cros_ec_sensors_cmd_read_u8(ec, EC_MEMMAP_ACC_STATUS,
> + &status);
> + if (ret < 0)
> + return ret;
> + }
> +
> + return status;
> +}
> +
> +/**
> + * read_ec_sensors_data_unsafe() - read acceleration data from EC shared memory
> + * @indio_dev: pointer to IIO 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.
> + *
> + * Return: 0 on success, -errno on failure.
> + */
> +static int cros_ec_sensors_read_data_unsafe(struct iio_dev *indio_dev,
> + unsigned long scan_mask, s16 *data)
> +{
> + struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
> + struct cros_ec_device *ec = st->ec;
> + unsigned int i;
> + int ret;
> +
> + /* Read all sensors enabled in scan_mask. Each value is 2 bytes. */
> + for_each_set_bit(i, &scan_mask, indio_dev->masklength) {
> + ret = cros_ec_sensors_cmd_read_u16(ec,
> + cros_ec_sensors_idx_to_reg(st, i),
> + data);
> + if (ret < 0)
> + return ret;
> +
> + data++;
> + }
> +
> + return 0;
> +}
> +
> +int cros_ec_sensors_read_lpc(struct iio_dev *indio_dev,
> + unsigned long scan_mask, s16 *data)
> +{
> + struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
> + struct cros_ec_device *ec = st->ec;
> + u8 samp_id = 0xff, status = 0;
> + int ret, 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. */
> + status = cros_ec_sensors_read_until_not_busy(st);
> + if (status < 0)
> + return status;
> +
> + /*
> + * 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. */
> + ret = cros_ec_sensors_read_data_unsafe(indio_dev, scan_mask,
> + data);
> + if (ret < 0)
> + return ret;
> +
> + /* Read status byte. */
> + ret = cros_ec_sensors_cmd_read_u8(ec, EC_MEMMAP_ACC_STATUS,
> + &status);
> + if (ret < 0)
> + return ret;
> + }
> +
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(cros_ec_sensors_read_lpc);
> +
> +int cros_ec_sensors_read_cmd(struct iio_dev *indio_dev,
> + unsigned long scan_mask, s16 *data)
> +{
> + struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
> + int ret;
> + unsigned int i = 0;
> +
Unless I am missing something, this initialization is unnecessary.

> + /* Read all sensor data through a command. */
> + st->param.cmd = MOTIONSENSE_CMD_DATA;
> + ret = cros_ec_motion_send_host_cmd(st, sizeof(st->resp->data));
> + if (ret != 0) {
> + dev_warn(&indio_dev->dev, "Unable to read sensor data\n");
> + return ret;
> + }
> +
> + for_each_set_bit(i, &scan_mask, indio_dev->masklength) {
> + *data = st->resp->data.data[i];
> + data++;
> + }
> +
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(cros_ec_sensors_read_cmd);
> +
> +irqreturn_t cros_ec_sensors_capture(int irq, void *p)
> +{
> + struct iio_poll_func *pf = p;
> + struct iio_dev *indio_dev = pf->indio_dev;
> + struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
> + int ret;
> +
> + mutex_lock(&st->cmd_lock);
> +
> + /* Clear capture data. */
> + memset(st->samples, 0, indio_dev->scan_bytes);
> +
> + /* Read data based on which channels are enabled in scan mask. */
> + ret = st->read_ec_sensors_data(indio_dev,
> + *(indio_dev->active_scan_mask),
> + (s16 *)st->samples);
> + if (ret < 0)
> + goto done;
> +
> + iio_push_to_buffers_with_timestamp(indio_dev, st->samples,
> + iio_get_time_ns(indio_dev));
> +
> +done:
> + /*
> + * Tell the core we are done with this trigger and ready for the
> + * next one.
> + */
> + iio_trigger_notify_done(indio_dev->trig);
> +
> + mutex_unlock(&st->cmd_lock);
> +
> + return IRQ_HANDLED;
> +}
> +EXPORT_SYMBOL_GPL(cros_ec_sensors_capture);
> +
> +int cros_ec_sensors_core_read(struct cros_ec_sensors_core_state *st,
> + struct iio_chan_spec const *chan,
> + int *val, int *val2, long mask)
> +{
> + int ret = IIO_VAL_INT;
> +
> + switch (mask) {
> + case IIO_CHAN_INFO_SAMP_FREQ:
> + st->param.cmd = MOTIONSENSE_CMD_EC_RATE;
> + st->param.ec_rate.data =
> + EC_MOTION_SENSE_NO_VALUE;
> +
> + if (cros_ec_motion_send_host_cmd(st, 0))
> + ret = -EIO;
> + else
> + *val = st->resp->ec_rate.ret;
> + break;
> + case IIO_CHAN_INFO_FREQUENCY:
> + st->param.cmd = MOTIONSENSE_CMD_SENSOR_ODR;
> + st->param.sensor_odr.data =
> + EC_MOTION_SENSE_NO_VALUE;
> +
> + if (cros_ec_motion_send_host_cmd(st, 0))
> + ret = -EIO;
> + else
> + *val = st->resp->sensor_odr.ret;
> + break;
> + default:
> + break;
> + }
> +
> + return ret;
> +}
> +EXPORT_SYMBOL_GPL(cros_ec_sensors_core_read);
> +
> +int cros_ec_sensors_core_write(struct cros_ec_sensors_core_state *st,
> + struct iio_chan_spec const *chan,
> + int val, int val2, long mask)
> +{
> + int ret = 0;
> +
> + switch (mask) {
> + case IIO_CHAN_INFO_FREQUENCY:
> + st->param.cmd = MOTIONSENSE_CMD_SENSOR_ODR;
> + st->param.sensor_odr.data = val;
> +
> + /* Always roundup, so caller gets at least what it asks for. */
> + st->param.sensor_odr.roundup = 1;
> +
> + if (cros_ec_motion_send_host_cmd(st, 0))
> + ret = -EIO;
> + break;
> + case IIO_CHAN_INFO_SAMP_FREQ:
> + st->param.cmd = MOTIONSENSE_CMD_EC_RATE;
> + st->param.ec_rate.data = val;
> +
> + if (cros_ec_motion_send_host_cmd(st, 0))
> + ret = -EIO;
> + else
> + st->curr_sampl_freq = val;
> + break;
> + default:
> + ret = -EINVAL;
> + break;
> + }
> + return ret;
> +}
> +EXPORT_SYMBOL_GPL(cros_ec_sensors_core_write);
> +
> +static int __maybe_unused cros_ec_sensors_prepare(struct device *dev)
> +{
> + struct platform_device *pdev = to_platform_device(dev);
> + struct iio_dev *indio_dev = platform_get_drvdata(pdev);
> + struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
> +
> + if (st->curr_sampl_freq == 0)
> + return 0;
> +
> + /*
> + * If the sensors are sampled at high frequency, we will not be able to
> + * sleep. Set to sampling to a long period if necessary.
> + */
> + if (st->curr_sampl_freq < CROS_EC_MIN_SUSPEND_SAMPLING_FREQUENCY) {
> + mutex_lock(&st->cmd_lock);
> + st->param.cmd = MOTIONSENSE_CMD_EC_RATE;
> + st->param.ec_rate.data = CROS_EC_MIN_SUSPEND_SAMPLING_FREQUENCY;
> + cros_ec_motion_send_host_cmd(st, 0);
> + mutex_unlock(&st->cmd_lock);
> + }
> +
> + return 0;
> +}
> +
> +static void __maybe_unused cros_ec_sensors_complete(struct device *dev)
> +{
> + struct platform_device *pdev = to_platform_device(dev);
> + struct iio_dev *indio_dev = platform_get_drvdata(pdev);
> + struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
> +
> + if (st->curr_sampl_freq == 0)
> + return;
> +
> + if (st->curr_sampl_freq < CROS_EC_MIN_SUSPEND_SAMPLING_FREQUENCY) {
> + mutex_lock(&st->cmd_lock);
> + st->param.cmd = MOTIONSENSE_CMD_EC_RATE;
> + st->param.ec_rate.data = st->curr_sampl_freq;
> + cros_ec_motion_send_host_cmd(st, 0);
> + mutex_unlock(&st->cmd_lock);
> + }
> +}
> +
In the chromeos code those functions were (optionally) used for PM.
The PM declarations are missing here, though, making the functions
unconditionally unused. If the PM functionality is added in a later
patch, maybe the functions should be added at that time as well ? Or
did the PM ops declaration get lost ?

> +MODULE_DESCRIPTION("ChromeOS EC sensor hub core functions");
> +MODULE_LICENSE("GPL v2");
> diff --git a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.h b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.h
> new file mode 100644
> index 0000000..92ac4f8
> --- /dev/null
> +++ b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.h
> @@ -0,0 +1,177 @@
> +/*
> + * ChromeOS EC sensor hub
> + *
> + * Copyright (C) 2016 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.
> + */
> +
> +#ifndef __CROS_EC_SENSORS_CORE_H
> +#define __CROS_EC_SENSORS_CORE_H
> +
> +#include <linux/irqreturn.h>
> +
> +enum {
> + CROS_EC_SENSOR_X,
> + CROS_EC_SENSOR_Y,
> + CROS_EC_SENSOR_Z,
> + CROS_EC_SENSOR_MAX_AXIS,
> +};
> +
> +/* EC returns sensor values using signed 16 bit registers */
> +#define CROS_EC_SENSOR_BITS 16
> +
> +/*
> + * 4 16 bit channels are allowed.
> + * Good enough for current sensors, they use up to 3 16 bit vectors.
> + */
> +#define CROS_EC_SAMPLE_SIZE (sizeof(s64) * 2)
> +
> +/* Minimum sampling period to use when device is suspending */
> +#define CROS_EC_MIN_SUSPEND_SAMPLING_FREQUENCY 1000 /* 1 second */
> +
> +/**
> + * struct cros_ec_sensors_core_state - state data for EC sensors IIO driver
> + * @ec: cros EC device structure
> + * @cmd_lock: lock used to prevent simultaneous access to the
> + * commands.
> + * @msg: cros EC command structure
> + * @param: motion sensor parameters structure
> + * @resp: motion sensor response structure
> + * @type: type of motion sensor
> + * @loc: location where the motion sensor is placed
> + * @calib: calibration parameters. Nothe that trigger
> + * captured data will always provide the calibrated
> + * data
> + * @samples: static array to hold data from a single capture.
> + * For each channel we need 2 bytes, except for
> + * the timestamp. The timestamp is always last and
> + * is always 8-byte aligned.
> + * @read_ec_sensors_data: function used for accessing sensors values
> + * @cuur_sampl_freq: current sampling period
> + */
> +struct cros_ec_sensors_core_state {
> + struct cros_ec_device *ec;
> + struct mutex cmd_lock;
> +
> + struct cros_ec_command *msg;
> + struct ec_params_motion_sense param;
> + struct ec_response_motion_sense *resp;
> +
> + enum motionsensor_type type;
> + enum motionsensor_location loc;
> +
> + struct calib_data {
> + s16 offset;
> + } calib[CROS_EC_SENSOR_MAX_AXIS];

Wondering - why is this a structure and not just a simple array ? I
understand this comes from the code in chromeos, but still ...

> +
> + u8 samples[CROS_EC_SAMPLE_SIZE];
> +
> + int (*read_ec_sensors_data)(struct iio_dev *indio_dev,
> + unsigned long scan_mask, s16 *data);
> +
> + int curr_sampl_freq;
> +};
> +
> +/**
> + * cros_ec_sensors_read_lpc() - retrieve data from EC shared memory
> + * @indio_dev: pointer to IIO 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 on success, -errno on failure.
> + */
> +int cros_ec_sensors_read_lpc(struct iio_dev *indio_dev, unsigned long scan_mask,
> + s16 *data);
> +
> +/**
> + * cros_ec_sensors_read_cmd() - retrieve data using the EC command protocol
> + * @indio_dev: pointer to IIO device
> + * @scan_mask: bitmap of the sensor indices to scan
> + * @data: location to store data
> + *
> + * Return: 0 on success, -errno on failure.
> + */
> +int cros_ec_sensors_read_cmd(struct iio_dev *indio_dev, unsigned long scan_mask,
> + s16 *data);
> +
> +/**
> + * cros_ec_sensors_core_init() - basic initialization of the core structure
> + * @pdev: platform device created for the sensors
> + * @indio_dev: iio device structure of the device
> + * @physical_device: true if the device refers to a physical device
> + *
> + * Return: 0 on success, -errno on failure.
> + */
> +int cros_ec_sensors_core_init(struct platform_device *pdev,
> + struct iio_dev *indio_dev, bool physical_device);
> +
> +/**
> + * cros_ec_sensors_capture() - the trigger handler function
> + * @irq: the interrupt number.
> + * @p: a pointer to the poll function.
> + *
> + * 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
> + */
> +irqreturn_t cros_ec_sensors_capture(int irq, void *p);
> +
> +/**
> + * cros_ec_motion_send_host_cmd() - send motion sense host command
> + * @st: pointer to state information for device
> + * @opt_length: optional length to reduce the response size, useful on the data
> + * path. Otherwise, the maximal allowed response size is used
> + *
> + * When called, the sub-command is assumed to be set in param->cmd.
> + *
> + * Return: 0 on success, -errno on failure.
> + */
> +int cros_ec_motion_send_host_cmd(struct cros_ec_sensors_core_state *st,
> + u16 opt_length);
> +
> +/**
> + * cros_ec_sensors_core_read() - function to request a value from the sensor
> + * @st: pointer to state information for device
> + * @chan: channel specification structure table
> + * @val: will contain one element making up the returned value
> + * @val2: will contain another element making up the returned value
> + * @mask: specifies which values to be requested
> + *
> + * Return: the type of value returned by the device
> + */
> +int cros_ec_sensors_core_read(struct cros_ec_sensors_core_state *st,
> + struct iio_chan_spec const *chan,
> + int *val, int *val2, long mask);
> +
> +/**
> + * cros_ec_sensors_core_write() - function to write a value to the sensor
> + * @st: pointer to state information for device
> + * @chan: channel specification structure table
> + * @val: first part of value to write
> + * @val2: second part of value to write
> + * @mask: specifies which values to write
> + *
> + * Return: the type of value returned by the device
> + */
> +int cros_ec_sensors_core_write(struct cros_ec_sensors_core_state *st,
> + struct iio_chan_spec const *chan,
> + int val, int val2, long mask);
> +
> +/* List of extended channel specification for all sensors */
> +extern const struct iio_chan_spec_ext_info cros_ec_sensors_ext_info[];
> +
> +#endif /* __CROS_EC_SENSORS_CORE_H */
> diff --git a/include/linux/mfd/cros_ec.h b/include/linux/mfd/cros_ec.h
> index d6539c1..7769ea6 100644
> --- a/include/linux/mfd/cros_ec.h
> +++ b/include/linux/mfd/cros_ec.h
> @@ -151,6 +151,15 @@ struct cros_ec_device {
> int event_size;
> };
>
> +/**
> + * struct cros_ec_sensor_platform - ChromeOS EC sensor platform information
> + *
> + * @sensor_num: Id of the sensor, as reported by the EC.
> + */
> +struct cros_ec_sensor_platform {
> + u8 sensor_num;
> +};
> +
> /* struct cros_ec_platform - ChromeOS EC platform information
> *
> * @ec_name: name of EC device (e.g. 'cros-ec', 'cros-pd', ...)
> diff --git a/include/linux/mfd/cros_ec_commands.h b/include/linux/mfd/cros_ec_commands.h
> index 76728ff..8826e0f 100644
> --- a/include/linux/mfd/cros_ec_commands.h
> +++ b/include/linux/mfd/cros_ec_commands.h
> @@ -1315,6 +1315,24 @@ enum motionsense_command {
> */
> MOTIONSENSE_CMD_KB_WAKE_ANGLE = 5,
>
> + /*
> + * Returns a single sensor data.
> + */
> + MOTIONSENSE_CMD_DATA = 6,
> +
> + /*
> + * Perform low level calibration.. On sensors that support it, ask to
> + * do offset calibration.
> + */
> + MOTIONSENSE_CMD_PERFORM_CALIB = 10,
> +
> + /*
> + * Sensor Offset command is a setter/getter command for the offset used
> + * for calibration. The offsets can be calculated by the host, or via
> + * PERFORM_CALIB command.
> + */
> + MOTIONSENSE_CMD_SENSOR_OFFSET = 11,
> +
> /* Number of motionsense sub-commands. */
> MOTIONSENSE_NUM_CMDS
> };
> @@ -1335,12 +1353,18 @@ enum motionsensor_id {
> enum motionsensor_type {
> MOTIONSENSE_TYPE_ACCEL = 0,
> MOTIONSENSE_TYPE_GYRO = 1,
> + MOTIONSENSE_TYPE_MAG = 2,
> + MOTIONSENSE_TYPE_PROX = 3,
> + MOTIONSENSE_TYPE_LIGHT = 4,
> + MOTIONSENSE_TYPE_ACTIVITY = 5,
> + MOTIONSENSE_TYPE_MAX
> };
>
> /* List of motion sensor locations. */
> enum motionsensor_location {
> MOTIONSENSE_LOC_BASE = 0,
> MOTIONSENSE_LOC_LID = 1,
> + MOTIONSENSE_LOC_MAX,
> };
>
> /* List of motion sensor chips. */
> @@ -1361,6 +1385,31 @@ enum motionsensor_chip {
> */
> #define EC_MOTION_SENSE_NO_VALUE -1
>
> +#define EC_MOTION_SENSE_INVALID_CALIB_TEMP 0x8000
> +
> +/* Set Calibration information */
> +#define MOTION_SENSE_SET_OFFSET 1
> +
> +struct ec_response_motion_sensor_data {
> + /* Flags for each sensor. */
> + uint8_t flags;
> + /* Sensor number the data comes from */
> + uint8_t sensor_num;
> + /* Each sensor is up to 3-axis. */
> + union {
> + int16_t data[3];
> + struct {
> + uint16_t rsvd;
> + uint32_t timestamp;
> + } __packed;
> + struct {
> + uint8_t activity; /* motionsensor_activity */
> + uint8_t state;
> + int16_t add_info[2];
> + };
> + };
> +} __packed;
> +
> struct ec_params_motion_sense {
> uint8_t cmd;
> union {
> @@ -1378,9 +1427,37 @@ struct ec_params_motion_sense {
> int16_t data;
> } ec_rate, kb_wake_angle;
>
> + /* Used for MOTIONSENSE_CMD_SENSOR_OFFSET */
> + struct {
> + uint8_t sensor_num;
> +
> + /*
> + * bit 0: If set (MOTION_SENSE_SET_OFFSET), set
> + * the calibration information in the EC.
> + * If unset, just retrieve calibration information.
> + */
> + uint16_t flags;
> +
> + /*
> + * Temperature at calibration, in units of 0.01 C
> + * 0x8000: invalid / unknown.
> + * 0x0: 0C
> + * 0x7fff: +327.67C
> + */
> + int16_t temp;
> +
> + /*
> + * Offset for calibration.
> + * Unit:
> + * Accelerometer: 1/1024 g
> + * Gyro: 1/1024 deg/s
> + * Compass: 1/16 uT
> + */
> + int16_t offset[3];
> + } __packed sensor_offset;
> +
> /* Used for MOTIONSENSE_CMD_INFO. */
> struct {
> - /* Should be element of enum motionsensor_id. */
> uint8_t sensor_num;
> } info;
>
> @@ -1410,11 +1487,14 @@ struct ec_response_motion_sense {
> /* Flags representing the motion sensor module. */
> uint8_t module_flags;
>
> - /* Flags for each sensor in enum motionsensor_id. */
> - uint8_t sensor_flags[EC_MOTION_SENSOR_COUNT];
> + /* Number of sensors managed directly by the EC. */
> + uint8_t sensor_count;
>
> - /* Array of all sensor data. Each sensor is 3-axis. */
> - int16_t data[3*EC_MOTION_SENSOR_COUNT];
> + /*
> + * Sensor data is truncated if response_max is too small
> + * for holding all the data.
> + */
> + struct ec_response_motion_sensor_data sensor[0];
> } dump;
>
> /* Used for MOTIONSENSE_CMD_INFO. */
> @@ -1429,6 +1509,9 @@ struct ec_response_motion_sense {
> uint8_t chip;
> } info;
>
> + /* Used for MOTIONSENSE_CMD_DATA */
> + struct ec_response_motion_sensor_data data;
> +
> /*
> * Used for MOTIONSENSE_CMD_EC_RATE, MOTIONSENSE_CMD_SENSOR_ODR,
> * MOTIONSENSE_CMD_SENSOR_RANGE, and
> @@ -1438,6 +1521,12 @@ struct ec_response_motion_sense {
> /* Current value of the parameter queried. */
> int32_t ret;
> } ec_rate, sensor_odr, sensor_range, kb_wake_angle;
> +
> + /* Used for MOTIONSENSE_CMD_SENSOR_OFFSET */
> + struct {
> + int16_t temp;
> + int16_t offset[3];
> + } sensor_offset, perform_calib;
> };
> } __packed;
>
> --
> 2.1.0
>

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