Re: [PATCH v5] iio: cros_ec: Add lid angle driver

[Jonathan Cameron]

On Fri, 29 Mar 2019 13:08:52 -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>
Hi Gwendal.

I'd really prefer if you didn't send new versions as replies to the older thread.
It just leads to very deep threads.  It's easy to associate a v5 with v4 thread
if anyone wants to, but it's hard to figure out that an email deep in a v4 thread
is infact about v5.

Looks like there is a lock held in an error path.  See inline.

Also, somewhere along the way your patch got corrupted by a few unwanted
line breaks.

Given this touches code under mfd, I'll be wanting an ack from Lee before
applying + whether he wants an immutable branch for this change.

Thanks,


Jonathan


> ---
> 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       | 138 ++++++++++++++++++
>  drivers/mfd/cros_ec_dev.c                     |  13 +-
>  4 files changed, 158 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..92be07d7fa36
> --- /dev/null
> +++ b/drivers/iio/common/cros_ec_sensors/cros_ec_lid_angle.c
> @@ -0,0 +1,138 @@
> +// 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)

Lock is still held.

> +		return ret;
> +	*val = data;
> +	mutex_unlock(&st->core.cmd_lock);
> +	return IIO_VAL_INT;
> +}
> +
> +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 d275deaecb12..52ea2f1c87a1 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)
Line break in the above means the patch doesn't apply.

> 
>  	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)
Line break here means patch doesn't apply.
>  		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);