Re: [PATCH] platform: add custom surface3 platform device for controlling LID

[Andy Shevchenko]

On Fri, Nov 25, 2016 at 6:11 PM, Benjamin Tissoires
<benjamin.tissoires@xxxxxxxxxx> wrote:
> The LID state provided by ACPI on the Surface 3 is not accurate.
> The ACPI node doesn't get notified on LID open, which means the
> LID input switch stays close most of the time.
>
> Fortunatelly, there is a WMI method which directly queries the
> GPIO underneath the LID state, so it's far more reliable than ACPI.
> To get the notifications that the LID was opened/closed, we can
> rely on the ACPI notification of the touchscreen: the DSDT shows
> that the touchscreen will get notified on close/open as it also
> controls its _STA method.
>
> Note that we need to set the tag "power-switch" to the LID
> input node through a udev rule for logind to accept it:
>
> SUBSYSTEM=="input", KERNEL=="event*", KERNELS=="surface3-wmi", \
>         TAG+="power-switch"

Pushed to testing with fixed Subject line (Pattern is "platform/x86:
Description").
Thanks.

>
> Signed-off-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>
> ---
>  drivers/platform/x86/Kconfig        |  12 ++
>  drivers/platform/x86/Makefile       |   1 +
>  drivers/platform/x86/surface3-wmi.c | 296 ++++++++++++++++++++++++++++++++++++
>  3 files changed, 309 insertions(+)
>  create mode 100644 drivers/platform/x86/surface3-wmi.c
>
> diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
> index b8a21d7..152aac6 100644
> --- a/drivers/platform/x86/Kconfig
> +++ b/drivers/platform/x86/Kconfig
> @@ -363,6 +363,18 @@ config IDEAPAD_LAPTOP
>           This is a driver for Lenovo IdeaPad netbooks contains drivers for
>           rfkill switch, hotkey, fan control and backlight control.
>
> +config SURFACE3_WMI
> +       tristate "Surface 3 WMI Driver"
> +       depends on ACPI_WMI
> +       depends on DMI
> +       depends on INPUT
> +       depends on SPI
> +       ---help---
> +         Say Y here if you have a Surface 3.
> +
> +         To compile this driver as a module, choose M here: the module will
> +         be called surface3-wmi.
> +
>  config THINKPAD_ACPI
>         tristate "ThinkPad ACPI Laptop Extras"
>         depends on ACPI
> diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
> index 2efa86d..38f5419 100644
> --- a/drivers/platform/x86/Makefile
> +++ b/drivers/platform/x86/Makefile
> @@ -34,6 +34,7 @@ obj-$(CONFIG_PANASONIC_LAPTOP)        += panasonic-laptop.o
>  obj-$(CONFIG_INTEL_MENLOW)     += intel_menlow.o
>  obj-$(CONFIG_ACPI_WMI)         += wmi.o
>  obj-$(CONFIG_MSI_WMI)          += msi-wmi.o
> +obj-$(CONFIG_SURFACE3_WMI)     += surface3-wmi.o
>  obj-$(CONFIG_TOPSTAR_LAPTOP)   += topstar-laptop.o
>
>  # toshiba_acpi must link after wmi to ensure that wmi devices are found
> diff --git a/drivers/platform/x86/surface3-wmi.c b/drivers/platform/x86/surface3-wmi.c
> new file mode 100644
> index 0000000..5553b2b
> --- /dev/null
> +++ b/drivers/platform/x86/surface3-wmi.c
> @@ -0,0 +1,296 @@
> +/*
> + *  Driver for the LID cover switch of the Surface 3
> + *
> + *  Copyright (c) 2016 Red Hat Inc.
> + */
> +
> +/*
> + * 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; version 2 of the License.
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/slab.h>
> +
> +#include <linux/acpi.h>
> +#include <linux/dmi.h>
> +#include <linux/input.h>
> +#include <linux/mutex.h>
> +#include <linux/platform_device.h>
> +#include <linux/spi/spi.h>
> +
> +MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>");
> +MODULE_DESCRIPTION("Surface 3 platform driver");
> +MODULE_LICENSE("GPL");
> +
> +#define ACPI_BUTTON_HID_LID            "PNP0C0D"
> +#define SPI_CTL_OBJ_NAME               "SPI"
> +#define SPI_TS_OBJ_NAME                        "NTRG"
> +
> +#define SURFACE3_LID_GUID "F7CC25EC-D20B-404C-8903-0ED4359C18AE"
> +
> +MODULE_ALIAS("wmi:" SURFACE3_LID_GUID);
> +
> +static const struct dmi_system_id surface3_dmi_table[] = {
> +#if defined(CONFIG_X86)
> +       {
> +               .matches = {
> +                       DMI_MATCH(DMI_SYS_VENDOR, "Microsoft Corporation"),
> +                       DMI_MATCH(DMI_PRODUCT_NAME, "Surface 3"),
> +               },
> +       },
> +#endif
> +       { }
> +};
> +
> +struct surface3_wmi {
> +       struct acpi_device *touchscreen_adev;
> +       struct acpi_device *pnp0c0d_adev;
> +       struct acpi_hotplug_context hp;
> +       struct input_dev *input;
> +};
> +
> +static struct platform_device *s3_wmi_pdev;
> +
> +static struct surface3_wmi s3_wmi;
> +
> +static DEFINE_MUTEX(s3_wmi_lock);
> +
> +static int s3_wmi_query_block(const char *guid, int instance, int *ret)
> +{
> +       acpi_status status;
> +       union acpi_object *obj;
> +
> +       struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
> +
> +       mutex_lock(&s3_wmi_lock);
> +       status = wmi_query_block(guid, instance, &output);
> +
> +       obj = output.pointer;
> +
> +       if (!obj || obj->type != ACPI_TYPE_INTEGER) {
> +               if (obj) {
> +                       pr_err("query block returned object type: %d - buffer length:%d\n",
> +                              obj->type,
> +                              obj->type == ACPI_TYPE_BUFFER ?
> +                                               obj->buffer.length : 0);
> +               }
> +               kfree(obj);
> +               return -EINVAL;
> +       }
> +       *ret = obj->integer.value;
> +       kfree(obj);
> +       mutex_unlock(&s3_wmi_lock);
> +       return 0;
> +}
> +
> +static inline int s3_wmi_query_lid(int *ret)
> +{
> +       return s3_wmi_query_block(SURFACE3_LID_GUID, 0, ret);
> +}
> +
> +static int s3_wmi_send_lid_state(void)
> +{
> +       int ret, lid_sw;
> +
> +       ret = s3_wmi_query_lid(&lid_sw);
> +       if (ret)
> +               return ret;
> +
> +       input_report_switch(s3_wmi.input, SW_LID, lid_sw);
> +       input_sync(s3_wmi.input);
> +
> +       return 0;
> +}
> +
> +static int s3_wmi_hp_notify(struct acpi_device *adev, u32 value)
> +{
> +       return s3_wmi_send_lid_state();
> +}
> +
> +static acpi_status s3_wmi_attach_spi_device(acpi_handle handle,
> +                                           u32 level,
> +                                           void *data,
> +                                           void **return_value)
> +{
> +       struct acpi_device *adev, **ts_adev;
> +
> +       if (acpi_bus_get_device(handle, &adev))
> +               return AE_OK;
> +
> +       ts_adev = data;
> +
> +       if (strncmp(acpi_device_bid(adev), SPI_TS_OBJ_NAME,
> +           strlen(SPI_TS_OBJ_NAME)))
> +               return AE_OK;
> +
> +       if (*ts_adev) {
> +               pr_err("duplicate entry %s\n", SPI_TS_OBJ_NAME);
> +               return AE_OK;
> +       }
> +
> +       *ts_adev = adev;
> +
> +       return AE_OK;
> +}
> +
> +static int s3_wmi_check_platform_device(struct device *dev, void *data)
> +{
> +       struct acpi_device *adev, *ts_adev;
> +       acpi_handle handle;
> +       acpi_status status;
> +
> +       /* ignore non ACPI devices */
> +       handle = ACPI_HANDLE(dev);
> +       if (!handle || acpi_bus_get_device(handle, &adev))
> +               return 0;
> +
> +       /* check for LID ACPI switch */
> +       if (!strcmp(ACPI_BUTTON_HID_LID, acpi_device_hid(adev))) {
> +               s3_wmi.pnp0c0d_adev = adev;
> +               return 0;
> +       }
> +
> +       /* ignore non SPI controllers */
> +       if (strncmp(acpi_device_bid(adev), SPI_CTL_OBJ_NAME,
> +           strlen(SPI_CTL_OBJ_NAME)))
> +               return 0;
> +
> +       status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
> +                                    s3_wmi_attach_spi_device, NULL,
> +                                    &ts_adev, NULL);
> +       if (ACPI_FAILURE(status))
> +               dev_warn(dev, "failed to enumerate SPI slaves\n");
> +
> +       if (!ts_adev)
> +               return 0;
> +
> +       s3_wmi.touchscreen_adev = ts_adev;
> +
> +       return 0;
> +}
> +
> +static int s3_wmi_create_and_register_input(struct platform_device *pdev)
> +{
> +       struct input_dev *input;
> +       int error;
> +
> +       input = devm_input_allocate_device(&pdev->dev);
> +       if (!input)
> +               return -ENOMEM;
> +
> +       input->name = "Lid Switch";
> +       input->phys = "button/input0";
> +       input->id.bustype = BUS_HOST;
> +       input->id.product = 0x0005;
> +
> +       input_set_capability(input, EV_SW, SW_LID);
> +
> +       error = input_register_device(input);
> +       if (error)
> +               goto out_err;
> +
> +       s3_wmi.input = input;
> +
> +       return 0;
> + out_err:
> +       input_free_device(s3_wmi.input);
> +       return error;
> +}
> +
> +static int __init s3_wmi_probe(struct platform_device *pdev)
> +{
> +       int error;
> +
> +       if (!dmi_check_system(surface3_dmi_table))
> +               return -ENODEV;
> +
> +       memset(&s3_wmi, 0, sizeof(s3_wmi));
> +
> +       bus_for_each_dev(&platform_bus_type, NULL, NULL,
> +                        s3_wmi_check_platform_device);
> +
> +       if (!s3_wmi.touchscreen_adev)
> +               return -ENODEV;
> +
> +       acpi_bus_trim(s3_wmi.pnp0c0d_adev);
> +
> +       error = s3_wmi_create_and_register_input(pdev);
> +       if (error)
> +               goto restore_acpi_lid;
> +
> +       acpi_initialize_hp_context(s3_wmi.touchscreen_adev, &s3_wmi.hp,
> +                                  s3_wmi_hp_notify, NULL);
> +
> +       s3_wmi_send_lid_state();
> +
> +       return 0;
> +
> + restore_acpi_lid:
> +       acpi_bus_scan(s3_wmi.pnp0c0d_adev->handle);
> +       return error;
> +}
> +
> +static int s3_wmi_remove(struct platform_device *device)
> +{
> +       /* remove the hotplug context from the acpi device */
> +       s3_wmi.touchscreen_adev->hp = NULL;
> +
> +       /* reinstall the actual PNPC0C0D LID default handle */
> +       acpi_bus_scan(s3_wmi.pnp0c0d_adev->handle);
> +       return 0;
> +}
> +
> +#ifdef CONFIG_PM
> +static int s3_wmi_resume(struct device *dev)
> +{
> +       s3_wmi_send_lid_state();
> +       return 0;
> +}
> +#endif
> +static SIMPLE_DEV_PM_OPS(s3_wmi_pm, NULL, s3_wmi_resume);
> +
> +static struct platform_driver s3_wmi_driver = {
> +       .driver = {
> +               .name = "surface3-wmi",
> +               .pm = &s3_wmi_pm,
> +       },
> +       .remove = s3_wmi_remove,
> +};
> +
> +static int __init s3_wmi_init(void)
> +{
> +       int error;
> +
> +       s3_wmi_pdev = platform_device_alloc("surface3-wmi", -1);
> +       if (!s3_wmi_pdev)
> +               return -ENOMEM;
> +
> +       error = platform_device_add(s3_wmi_pdev);
> +       if (error)
> +               goto err_device_put;
> +
> +       error = platform_driver_probe(&s3_wmi_driver, s3_wmi_probe);
> +       if (error)
> +               goto err_device_del;
> +
> +       pr_info("Surface 3 WMI Extras loaded\n");
> +       return 0;
> +
> + err_device_del:
> +       platform_device_del(s3_wmi_pdev);
> + err_device_put:
> +       platform_device_put(s3_wmi_pdev);
> +       return error;
> +}
> +
> +static void __exit s3_wmi_exit(void)
> +{
> +       platform_device_unregister(s3_wmi_pdev);
> +       platform_driver_unregister(&s3_wmi_driver);
> +}
> +
> +module_init(s3_wmi_init);
> +module_exit(s3_wmi_exit);
> --
> 2.7.4
>
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-- 
With Best Regards,
Andy Shevchenko