Re: [PATCH v2 1/3] x86: add support for Huawei WMI hotkeys.

[Andy Shevchenko]

On Fri, Nov 2, 2018 at 6:11 AM Ayman Bagabas <ayman.bagabas@xxxxxxxxx> wrote:
>
> This driver adds support for missing hotkeys on some Huawei laptops.
> Currently, only Huawei Matebook X Pro is supported. The driver
> recognizes the following keys: brightness keys, micmute, wlan, and
> Huawei special key. The brightness keys are ignored since they work out
> of the box.

> +config HUAWEI_LAPTOP
> +       tristate "Huawei WMI hotkeys driver"
> +       depends on ACPI

> +       depends on ACPI_WMI


> +       depends on INPUT
> +       select INPUT_SPARSEKMAP
> +       help
> +         This driver provides support for Huawei WMI hotkeys.
> +         It enables the missing keys and adds support to micmute
> +         led found on these laptops.q
> +         Supported devices are:
> +         - Matebook X Pro


> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + *  Huawei WMI Hotkeys Driver
> + *
> + *  Copyright (C) 2018           Ayman Bagabas <ayman.bagabas@xxxxxxxxx>
> + *
> + *  This program is free software: you can redistribute it and/or modify
> + *  it under the terms of the GNU General Public License as published by
> + *  the Free Software Foundation, either version 2 of the License, or
> + *  (at your option) any later version.
> + *
> + *  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.
> + *
> + *  You should have received a copy of the GNU General Public License
> + *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
> + *
> + */

> +MODULE_LICENSE("GPL");


Here you have the following issues:
- inconsistency between IDs for license (fix accordingly)
- SDPX _and_ License header (remove latter)


> +#include <linux/kernel.h>

> +#include <linux/module.h>
> +#include <linux/init.h>

Choose one of them.

> +#include <linux/input.h>
> +#include <linux/input/sparse-keymap.h>
> +#include <linux/acpi.h>
> +#include <linux/wmi.h>

Please, keep in order.

> +static const struct key_entry huawei_wmi_keymap[] __initconst = {
> +               { KE_IGNORE, 0x281, { KEY_BRIGHTNESSDOWN } },
> +               { KE_IGNORE, 0x282, { KEY_BRIGHTNESSUP } },
> +               { KE_KEY,       0x287, { KEY_MICMUTE } },
> +               { KE_KEY,       0x289, { KEY_WLAN } },
> +               // Huawei |M| button
> +               { KE_KEY,       0x28a, { KEY_PROG1 } },
> +               { KE_END,       0 }
> +};
> +

> +struct huawei_wmi_device {
> +       struct input_dev *inputdev;
> +};

Apparently no need to have this, you may use struct input_dev
directly, isn't it?

> +static struct huawei_wmi_device *wmi_device;

No global variables, please.

> +int huawei_wmi_micmute_led_set(bool on)
> +{
> +       u32 args = (on) ? MICMUTE_LED_ON : MICMUTE_LED_OFF;

Redundant parens.

> +       struct acpi_buffer input = { (acpi_size)sizeof(args), &args };
> +       acpi_status status;
> +
> +       status = wmi_evaluate_method(AMW0_GUID, 0, 1, &input, NULL);
> +       if (ACPI_FAILURE(status))
> +               return status;
> +
> +       return 0;
> +}

> +static void huawei_wmi_process_key(struct input_dev *input_dev, int code)
> +{
> +       const struct key_entry *key;
> +

> +       key = sparse_keymap_entry_from_scancode(input_dev, code);
> +

This blank line is redundant.

> +       if (!key) {
> +               pr_info("%s: Unknown key pressed, code: 0x%04x\n",
> +                                       MODULE_NAME, code);

dev_info(); no MODULE_NAME, please.

> +               return;
> +       }
> +
> +       sparse_keymap_report_entry(input_dev, key, 1, true);
> +}

> +static void huawei_wmi_notify(u32 value, void *context)
> +{
> +       struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
> +       union acpi_object *obj;
> +       acpi_status status;
> +
> +       status = wmi_get_event_data(value, &response);
> +       if (ACPI_FAILURE(status)) {

> +               pr_err("%s: Bad event status 0x%x\n",
> +                                       MODULE_NAME, status);

No MODULE_NAME, please.
If needed, use pr_fmt() macro.

But I'm pretty sure you may pass pointer to input device and use dev_err().

> +               return;
> +       }
> +

> +       obj = (union acpi_object *)response.pointer;
> +

No redundant blank lines, please.

> +       if (!obj)
> +               return;
> +
> +       if (obj->type == ACPI_TYPE_INTEGER)
> +               huawei_wmi_process_key(wmi_device->inputdev,
> +                                                       obj->integer.value);
> +       else

> +               pr_info("%s: Unknown response received %d\n",
> +                                       MODULE_NAME, obj->type);

Ditto about module name.

> +
> +       kfree(response.pointer);
> +}
> +
> +static int huawei_input_init(void)
> +{
> +       acpi_status status;
> +       int err;

> +       status = wmi_install_notify_handler(EVENT_GUID,
> +                       huawei_wmi_notify,

> +                       NULL);

Pointer to the input device instead of NULL.

> +

No redundant blank lines, please.

> +       if (ACPI_FAILURE(status)) {
> +               err = -EIO;
> +               goto err_free_dev;
> +       }

> +}


> +       wmi_device = kmalloc(sizeof(struct huawei_wmi_device), GFP_KERNEL);

sizeof(*wmi_device)

> +       if (!wmi_device)
> +               return -ENOMEM;

> +}


> +       pr_debug("%s: Driver unloaded successfully\n", MODULE_NAME);

Noise.

--
With Best Regards,
Andy Shevchenko