On Sun, Mar 3, 2019 at 4:43 AM Jonathan Cameron <jic23@xxxxxxxxxx> wrote:
>
> On Thu, 28 Feb 2019 09:41:54 -0800
> 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>
>
> Hi Gwendal,
>
> Just a few minor comments inline. It seems a bit like this has been
> copied from a driver needing a lot more flexibility and as a result
> various items that can be hard coded, simplifying this, are left
> flexible.
>
> Also one question about the cros_ec part.
>
> Jonathan
Thanks for the review, v3 coming soon.
Gwendal.
>
> > ---
> > 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 | 163 ++++++++++++++++++
> > drivers/mfd/cros_ec_dev.c | 15 +-
> > 4 files changed, 185 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..09d30976a743
> > --- /dev/null
> > +++ b/drivers/iio/common/cros_ec_sensors/cros_ec_lid_angle.c
> > @@ -0,0 +1,163 @@
> > +// 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.
> > + */
> > +#define MAX_CHANNELS (1 + 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;
> > +
> > + struct iio_chan_spec channels[MAX_CHANNELS];
> > +};
> > +
> > +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;
> > + }
> > +
> > + if (scan_mask & 1)
>
> As below, this seems like flexibility with no benefit. I think it
> is always true.
Done.
>
> > + *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);
> > + u16 data;
> > + int ret;
> > + int idx = chan->scan_index;
> > +
> > + mutex_lock(&st->core.cmd_lock);
> > + switch (mask) {
> > + case IIO_CHAN_INFO_RAW:
> > + ret = cros_ec_sensors_read_lid_angle(
> > + indio_dev, 1 << idx, &data);
>
> This seems to suffer a bit from unwarranted flexibility.
> idx is always 0 in this driver - hence there is an obvious
> simplification!
Done: I kept cros_ec_sensors_read_lid_angle as it is use when
populating /dev/iio:deviceX.
>
> > + if (ret)
> > + break;
> > + ret = IIO_VAL_INT;
> > + *val = data;
> > + break;
> > + default:
> > + ret = -EINVAL;
> > + }
> > + 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;
> > + struct iio_chan_spec *channel;
> > + 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);
> > + channel = state->channels;
> > +
> > + channel->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
> > + channel->scan_type.realbits = CROS_EC_SENSOR_BITS;
> > + channel->scan_type.storagebits = CROS_EC_SENSOR_BITS;
> > + channel->scan_type.shift = 0;
>
> Shift has an 'obvious' default of 0 so I wouldn't bother
> explicitly setting it.
Done.
>
> > + channel->scan_index = 0;
> > + channel->scan_type.sign = 'u';
> > + channel->type = IIO_ANGL;
> > +
> > + state->core.calib[0] = 0;
> > +
> > + /* Timestamp */
> > + channel++;
> > + channel->type = IIO_TIMESTAMP;
> > + channel->channel = -1;
> > + channel->scan_index = 1;
> > + channel->scan_type.sign = 's';
> > + channel->scan_type.realbits = 64;
> > + channel->scan_type.storagebits = 64;
> > +
>
> These appear to be constant. Why not just use a static
> const array for them rather than within the state structure?
Done.
>
> > + indio_dev->channels = state->channels;
> > + indio_dev->num_channels = MAX_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 d275deaecb12..11b5b2fd1f33 100644
> > --- a/drivers/mfd/cros_ec_dev.c
> > +++ b/drivers/mfd/cros_ec_dev.c
> > @@ -297,13 +297,17 @@ 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 extra sensors if lid angle sensor or FIFO are needed.
> > + */
> > +#define NUM_EXTRA_SENSORS 2
> > + sensor_cells = kcalloc(sensor_num + NUM_EXTRA_SENSORS,
> > + sizeof(struct mfd_cell),
> > GFP_KERNEL);
> > if (sensor_cells == NULL)
> > goto error;
> >
> > - sensor_platforms = kcalloc(sensor_num + 1,
> > + sensor_platforms = kcalloc(sensor_num,
>
> This change has me curious. Why was the +1 ever needed?
No, it was a mistake.
> As far as I can see we only ever use <= sensor_num entries in this array.
>
> > sizeof(struct cros_ec_sensor_platform),
> > GFP_KERNEL);
> > if (sensor_platforms == NULL)
> > @@ -363,6 +367,11 @@ 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);
>
