Re: [PATCH v6] iio: cros_ec: Add lid angle driver

From: Gwendal Grignou
Date: Sat Apr 27 2019 - 17:28:28 EST


On Sat, Apr 27, 2019 at 6:24 AM Jonathan Cameron
<jic23@xxxxxxxxxxxxxxxxxxxxx> wrote:
>
> On Sat, 27 Apr 2019 14:21:12 +0100
> Jonathan Cameron <jic23@xxxxxxxxxx> wrote:
>
> > On Wed, 24 Apr 2019 17:29:32 -0700
> > Gwendal Grignou <gwendal@xxxxxxxxxxxx> wrote:
> >
> > > Add a IIO driver that reports the angle between the lid and the base for
> > > ChromeOS convertible device.
> > >
> > Tested on eve with ToT EC firmware.
> > > Check driver is loaded and lid angle is correct.
> > >
> > > Signed-off-by: Gwendal Grignou <gwendal@xxxxxxxxxxxx>
> > I am a little curious... In what way is this a counter driver (comments
> > at the top of the main file)?
It is a mistake, I used another driver .c file as a starting point. I
will fix it.
> >
> > Anyhow, that's no reason not to apply it. However, it has just missed
> > the coming merge window unless Linus makes 'it is delayed noises' tomorrow.
> >
> > Applied to the togreg branch of iio.git and pushed out as testing
> > for the autobuilders to play with it.
> Ah. Should have waited for my local build test to finish.
>
> I'm guessing this has a dependency I don't know about?
> MOTIONSENSE_CMD_LID_ANGLE isn't defined.
Yes, that constant is part of the cros_ec_commands.h update, in patch
"[PATCH 15/30] mfd: cros_ec: Complete MEMS sensor API"

Gwendal.
>
> Jonathan
>
> >
> > Thanks,
> >
> > Jonathan
> >
> > > ---
> > > Changes in v6:
> > > - Fix lock held in an error path error.
> > >
> > > Changes in v5:
> > > - Remove unnecessary define.
> > > - v4 was the wrong patch file
> > >
> > > Changes in v3:
> > > - Use static channel array, simplify code because index is always 0.
> > >
> > > Changes in v2:
> > > - Fix license, remove driver_module field.
> > >
> > > drivers/iio/common/cros_ec_sensors/Kconfig | 9 ++
> > > drivers/iio/common/cros_ec_sensors/Makefile | 1 +
> > > .../cros_ec_sensors/cros_ec_lid_angle.c | 139 ++++++++++++++++++
> > > drivers/mfd/cros_ec_dev.c | 13 +-
> > > 4 files changed, 159 insertions(+), 3 deletions(-)
> > > create mode 100644 drivers/iio/common/cros_ec_sensors/cros_ec_lid_angle.c
> > >
> > > diff --git a/drivers/iio/common/cros_ec_sensors/Kconfig b/drivers/iio/common/cros_ec_sensors/Kconfig
> > > index 135f6825903f..aacc2ab9c34f 100644
> > > --- a/drivers/iio/common/cros_ec_sensors/Kconfig
> > > +++ b/drivers/iio/common/cros_ec_sensors/Kconfig
> > > @@ -20,3 +20,12 @@ config IIO_CROS_EC_SENSORS
> > > Accelerometers, Gyroscope and Magnetometer that are
> > > presented by the ChromeOS EC Sensor hub.
> > > Creates an IIO device for each functions.
> > > +
> > > +config IIO_CROS_EC_SENSORS_LID_ANGLE
> > > + tristate "ChromeOS EC Sensor for lid angle"
> > > + depends on IIO_CROS_EC_SENSORS_CORE
> > > + help
> > > + Module to report the angle between lid and base for some
> > > + convertible devices.
> > > + This module is loaded when the EC can calculate the angle between the base
> > > + and the lid.
> > > diff --git a/drivers/iio/common/cros_ec_sensors/Makefile b/drivers/iio/common/cros_ec_sensors/Makefile
> > > index ec716ff2a775..a35ee232ac07 100644
> > > --- a/drivers/iio/common/cros_ec_sensors/Makefile
> > > +++ b/drivers/iio/common/cros_ec_sensors/Makefile
> > > @@ -4,3 +4,4 @@
> > >
> > > obj-$(CONFIG_IIO_CROS_EC_SENSORS_CORE) += cros_ec_sensors_core.o
> > > obj-$(CONFIG_IIO_CROS_EC_SENSORS) += cros_ec_sensors.o
> > > +obj-$(CONFIG_IIO_CROS_EC_SENSORS_LID_ANGLE) += cros_ec_lid_angle.o
> > > diff --git a/drivers/iio/common/cros_ec_sensors/cros_ec_lid_angle.c b/drivers/iio/common/cros_ec_sensors/cros_ec_lid_angle.c
> > > new file mode 100644
> > > index 000000000000..876dfd176b0e
> > > --- /dev/null
> > > +++ b/drivers/iio/common/cros_ec_sensors/cros_ec_lid_angle.c
> > > @@ -0,0 +1,139 @@
> > > +// SPDX-License-Identifier: GPL-2.0
> > > +
> > > +/*
> > > + * cros_ec_lid_angle - Driver for CrOS EC lid angle sensor.
> > > + *
> > > + * Copyright 2018 Google, Inc
> > > + *
> > > + * This driver uses the cros-ec interface to communicate with the Chrome OS
> > > + * EC about counter sensors. Counters are presented through
> > > + * iio sysfs.
> > > + */
> > > +
> > > +#include <linux/delay.h>
> > > +#include <linux/device.h>
> > > +#include <linux/iio/buffer.h>
> > > +#include <linux/iio/common/cros_ec_sensors_core.h>
> > > +#include <linux/iio/iio.h>
> > > +#include <linux/iio/kfifo_buf.h>
> > > +#include <linux/iio/trigger.h>
> > > +#include <linux/iio/triggered_buffer.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/platform_device.h>
> > > +#include <linux/slab.h>
> > > +
> > > +#define DRV_NAME "cros-ec-lid-angle"
> > > +
> > > +/*
> > > + * One channel for the lid angle, the other for timestamp.
> > > + */
> > > +static const struct iio_chan_spec cros_ec_lid_angle_channels[] = {
> > > + {
> > > + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
> > > + .scan_type.realbits = CROS_EC_SENSOR_BITS,
> > > + .scan_type.storagebits = CROS_EC_SENSOR_BITS,
> > > + .scan_type.sign = 'u',
> > > + .type = IIO_ANGL
> > > + },
> > > + IIO_CHAN_SOFT_TIMESTAMP(1)
> > > +};
> > > +
> > > +/* State data for ec_sensors iio driver. */
> > > +struct cros_ec_lid_angle_state {
> > > + /* Shared by all sensors */
> > > + struct cros_ec_sensors_core_state core;
> > > +};
> > > +
> > > +static int cros_ec_sensors_read_lid_angle(struct iio_dev *indio_dev,
> > > + unsigned long scan_mask, s16 *data)
> > > +{
> > > + struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
> > > + int ret;
> > > +
> > > + st->param.cmd = MOTIONSENSE_CMD_LID_ANGLE;
> > > + ret = cros_ec_motion_send_host_cmd(st, sizeof(st->resp->lid_angle));
> > > + if (ret) {
> > > + dev_warn(&indio_dev->dev, "Unable to read lid angle\n");
> > > + return ret;
> > > + }
> > > +
> > > + *data = st->resp->lid_angle.value;
> > > + return 0;
> > > +}
> > > +
> > > +static int cros_ec_lid_angle_read(struct iio_dev *indio_dev,
> > > + struct iio_chan_spec const *chan,
> > > + int *val, int *val2, long mask)
> > > +{
> > > + struct cros_ec_lid_angle_state *st = iio_priv(indio_dev);
> > > + s16 data;
> > > + int ret;
> > > +
> > > + mutex_lock(&st->core.cmd_lock);
> > > + ret = cros_ec_sensors_read_lid_angle(indio_dev, 1, &data);
> > > + if (ret == 0) {
> > > + *val = data;
> > > + ret = IIO_VAL_INT;
> > > + }
> > > + mutex_unlock(&st->core.cmd_lock);
> > > + return ret;
> > > +}
> > > +
> > > +static const struct iio_info cros_ec_lid_angle_info = {
> > > + .read_raw = &cros_ec_lid_angle_read,
> > > +};
> > > +
> > > +static int cros_ec_lid_angle_probe(struct platform_device *pdev)
> > > +{
> > > + struct device *dev = &pdev->dev;
> > > + struct iio_dev *indio_dev;
> > > + struct cros_ec_lid_angle_state *state;
> > > + int ret;
> > > +
> > > + indio_dev = devm_iio_device_alloc(dev, sizeof(*state));
> > > + if (!indio_dev)
> > > + return -ENOMEM;
> > > +
> > > + ret = cros_ec_sensors_core_init(pdev, indio_dev, false);
> > > + if (ret)
> > > + return ret;
> > > +
> > > + indio_dev->info = &cros_ec_lid_angle_info;
> > > + state = iio_priv(indio_dev);
> > > + indio_dev->channels = cros_ec_lid_angle_channels;
> > > + indio_dev->num_channels = ARRAY_SIZE(cros_ec_lid_angle_channels);
> > > +
> > > + state->core.read_ec_sensors_data = cros_ec_sensors_read_lid_angle;
> > > +
> > > + ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL,
> > > + cros_ec_sensors_capture, NULL);
> > > + if (ret)
> > > + return ret;
> > > +
> > > + return devm_iio_device_register(dev, indio_dev);
> > > +}
> > > +
> > > +static const struct platform_device_id cros_ec_lid_angle_ids[] = {
> > > + {
> > > + .name = DRV_NAME,
> > > + },
> > > + { /* sentinel */ }
> > > +};
> > > +MODULE_DEVICE_TABLE(platform, cros_ec_lid_angle_ids);
> > > +
> > > +static struct platform_driver cros_ec_lid_angle_platform_driver = {
> > > + .driver = {
> > > + .name = DRV_NAME,
> > > + .pm = &cros_ec_sensors_pm_ops,
> > > + },
> > > + .probe = cros_ec_lid_angle_probe,
> > > + .id_table = cros_ec_lid_angle_ids,
> > > +};
> > > +module_platform_driver(cros_ec_lid_angle_platform_driver);
> > > +
> > > +MODULE_DESCRIPTION("ChromeOS EC driver for reporting convertible lid angle.");
> > > +MODULE_LICENSE("GPL v2");
> > > diff --git a/drivers/mfd/cros_ec_dev.c b/drivers/mfd/cros_ec_dev.c
> > > index a3b319913097..c410aa804698 100644
> > > --- a/drivers/mfd/cros_ec_dev.c
> > > +++ b/drivers/mfd/cros_ec_dev.c
> > > @@ -297,13 +297,15 @@ static void cros_ec_sensors_register(struct cros_ec_dev *ec)
> > >
> > > resp = (struct ec_response_motion_sense *)msg->data;
> > > sensor_num = resp->dump.sensor_count;
> > > - /* Allocate 1 extra sensors in FIFO are needed */
> > > - sensor_cells = kcalloc(sensor_num + 1, sizeof(struct mfd_cell),
> > > + /*
> > > + * Allocate 2 extra sensors if lid angle sensor and/or FIFO are needed.
> > > + */
> > > + sensor_cells = kcalloc(sensor_num + 2, sizeof(struct mfd_cell),
> > > GFP_KERNEL);
> > > if (sensor_cells == NULL)
> > > goto error;
> > >
> > > - sensor_platforms = kcalloc(sensor_num + 1,
> > > + sensor_platforms = kcalloc(sensor_num,
> > > sizeof(struct cros_ec_sensor_platform),
> > > GFP_KERNEL);
> > > if (sensor_platforms == NULL)
> > > @@ -363,6 +365,11 @@ static void cros_ec_sensors_register(struct cros_ec_dev *ec)
> > > sensor_cells[id].name = "cros-ec-ring";
> > > id++;
> > > }
> > > + if (cros_ec_check_features(ec,
> > > + EC_FEATURE_REFINED_TABLET_MODE_HYSTERESIS)) {
> > > + sensor_cells[id].name = "cros-ec-lid-angle";
> > > + id++;
> > > + }
> > >
> > > ret = mfd_add_devices(ec->dev, 0, sensor_cells, id,
> > > NULL, 0, NULL);
> >
>