Re: [PATCH v4 1/4] iio: cros_ec_sensors_core: Add common functions for the ChromeOS EC Sensor Hub.

Jonathan Cameron
2016-09-03T17:08:03Z

On 15/08/16 16:28, Jonathan Cameron wrote:
> On 01/08/16 10:54, Enric Balletbo i Serra 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>
> Reviewed-by: Jonathan Cameron <jic23@kernel.org>
Applied to a new branch in IIO for the purpose.
ib-iio-mfd-4.9

Not entirely sure which route I'll take to unwinding this to upstream
so it may go through a merge into iio.git or a separate pull request.

Will figure that out later!

Thanks,

Jonathan
>
> Thanks,
>
> Jonathan
>> ---
>>
>> Changes since v3:
>> - Convert structure to a simple array
>> - Remove PM declarations
>> - Remove unnecessary initializations
>> - cros_ec_sensors_cmd_read_u16: Conversion should only be done if ret >= 0
>> - Remove unnecessary else
>>
>> 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 | 450 +++++++++++++++++++++
>> .../common/cros_ec_sensors/cros_ec_sensors_core.h | 175 ++++++++
>> include/linux/mfd/cros_ec.h | 9 +
>> include/linux/mfd/cros_ec_commands.h | 99 ++++-
>> 9 files changed, 767 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..a3be799
>> --- /dev/null
>> +++ b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
>> @@ -0,0 +1,450 @@
>> +/*
>> + * 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] = 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);
>> +
>> + 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);
>> +
>> + if (ret >= 0)
>> + *dest = le16_to_cpu(tmp);
>> +
>> + 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;
>> +
>> + /* 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);
>> +
>> +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..8bc2ca3
>> --- /dev/null
>> +++ b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.h
>> @@ -0,0 +1,175 @@
>> +/*
>> + * 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. Note 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;
>> +
>> + s16 calib[CROS_EC_SENSOR_MAX_AXIS];
>> +
>> + 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;
>>
>>
>
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