Re: [PATCH v2 1/4] iio: cros_ec_sensors_core: Add common functions for the ChromeOS EC Sensor Hub.
From: Jonathan Cameron
Date: Tue Jul 26 2016 - 17:05:53 EST
On 25/07/16 09:38, Enric Balletbo Serra wrote:
> Hi Jonathan,
>
> Many thanks for the review, some answers below.
>
> 2016-07-24 15:51 GMT+02:00 Jonathan Cameron <jic23@xxxxxxxxxx>:
>> On 20/07/16 10:22, 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@xxxxxxxxxxxx>
>>> Signed-off-by: Guenter Roeck <groeck@xxxxxxxxxxxx>
>>> [eballetbo: split, squash and rebase on top of mainline the patches
>>> found in ChromeOS tree]
>>> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@xxxxxxxxxxxxx>
>> Few minor bits inline. I'm happy enough with the ABI (except that I would
>> like a justification for why userspace needs the id one)
>> We should see if anyone else has comments on that.
>>
>> The location one may well become more general in future (to cover other
>> devices).
>>
>> Jonathan
>>> ---
>>>
>>> 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 | 25 +
>>> 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 | 505 +++++++++++++++++++++
>>> .../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, 831 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..3e626b6
>>> --- /dev/null
>>> +++ b/Documentation/ABI/testing/sysfs-bus-iio-cros-ec
>>> @@ -0,0 +1,25 @@
>>> +What: /sys/bus/iio/devices/iio:deviceX/calibrate
>>> +Date: July 2015
>>> +KernelVersion: 4.7
>>> +Contact: linux-iio@xxxxxxxxxxxxxxx
>>> +Description:
>>> + Writing '1' will perform a FOC (Fast Online Calibration). The
>>> + corresponding calibration offsets can be read from *_calibbias
>>> + entries.
>> This one is fine as far as I'm concerned.
>>> +
>>> +What: /sys/bus/iio/devices/iio:deviceX/id
>>> +Date: July 2015
>>> +KernelVersion: 4.7
>>> +Contact: linux-iio@xxxxxxxxxxxxxxx
>>> +Description:
>>> + The id attribute holds an unique number for the motion sensor
>>> + identification, as reported by the ChromeOS Embedded Controller.
>> Mostly with these, we've just spat the out to the kernel logs as dev_info
>> during startup.
>>
>> Any reason this needs to be more explictly exposed to userspace?
>
> After think a bit more about this, and to be honest, I'm not sure if
> this is really useful to be exposed to userspace. The only use case
> that I'm thinking is that some userspace app uses it to uniquely
> identify the sensors that hang from the ChromeOS Embedded Controller,
> but I'm not sure about this exist. I'll investigate a bit more for if
> I find a good justification, otherwise I'll remove this.
>
> Maybe someone from chromium can give us more opinions?
>
>>> +
>>> +What: /sys/bus/iio/devices/iio:deviceX/location
>>> +Date: July 2015
>>> +KernelVersion: 4.7
>>> +Contact: linux-iio@xxxxxxxxxxxxxxx
>>> +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.
>> Interesting...
>>
>> We'll probably want to ultimately use this one more generally. This probably
>> won't be the last sensor where we have some means of finding this out!
>>
> Ok, I will rewrite the sentence to be more generic
Actually I wasn't implying there was anything that needed changing in this
description, more that we might want to 'promote' it to sysfs-bus-iio at
somepoint in the near future (or maybe right now).
>
>> Please include a list of possible values in the description.
>
> For now lid and base are the values used, is that ok?
>
Absolutely. As more options turn up we can expand the valid list.
>>> \ No newline at end of file
>> Fix that ;)
>
> Yep, sorry my bad.
>
>>> 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..70e3c17
>>> --- /dev/null
>>> +++ b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
>>> @@ -0,0 +1,505 @@
>>> +/*
>>> + * 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_id(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, "%d\n", st->param.info.sensor_num);
>>> +}
>>> +
>>> +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 = "id",
>>> + .shared = IIO_SHARED_BY_ALL,
>>> + .read = cros_ec_sensors_id
>>> + },
>>> + {
>>> + .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
>>> + 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);
>>> +
>>> + 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;
>>> +
>>> + /* 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());
>> The iio_get_time_ns now takes an indio_dev (as we support clock type
>> selection now).
>
> Just found it, fixed in next v3.
>
>>> +
>>> +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);
>>> + }
>>> +}
>>> +
>>> +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..69e09dc
>>> --- /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 bytees, except for
>> typo : bytes
>>> + * 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];
>>> +
>>> + 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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