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
> ---
> 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.
> + *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!
> + 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.
> + 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?
> + 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?
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);
