Re: [PATCH] platform: add samsung-wmi driver for newer Samsung laptops

[Gavin Li <gavinli@thegavinli.com>]

Actually there is an issue that affects the functionality of the
driver; I will have to work on this a bit more first. Thanks for the
feedback.

Gavin

On Thu, Apr 16, 2015 at 3:30 AM, Gavin Li <gavinli@thegavinli.com> wrote:
> Actually there is an issue that affects the functionality of the driver; I
> will have to work on this a bit more first. Thanks for the feedback.
>
> Gavin
>
> On Thu, Apr 16, 2015 at 12:04 AM, Corentin Chary <corentin.chary@gmail.com>
> wrote:
>>
>> On Tue, Apr 7, 2015 at 6:53 PM,  <gavinli@thegavinli.com> wrote:
>> > From: Gavin Li <git@thegavinli.com>
>> >
>> > This driver adds support for coarse (on or off) fan control and
>> > the keyboard backlight on newer Samsung laptops.
>> > ---
>> >  drivers/platform/x86/Kconfig       |  10 ++
>> >  drivers/platform/x86/Makefile      |   1 +
>> >  drivers/platform/x86/samsung-wmi.c | 221
>> > +++++++++++++++++++++++++++++++++++++
>> >  3 files changed, 232 insertions(+)
>> >  create mode 100644 drivers/platform/x86/samsung-wmi.c
>> >
>> > diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
>> > index 9752761..96f4620 100644
>> > --- a/drivers/platform/x86/Kconfig
>> > +++ b/drivers/platform/x86/Kconfig
>> > @@ -813,6 +813,16 @@ config SAMSUNG_LAPTOP
>> >           To compile this driver as a module, choose M here: the module
>> >           will be called samsung-laptop.
>> >
>> > +config SAMSUNG_WMI
>> > +       tristate "Samsung WMI driver (for newer Samsung laptops)"
>> > +       depends on ACPI
>> > +       depends on ACPI_WMI
>> > +       select LEDS_CLASS
>> > +       select NEW_LEDS
>> > +         ---help---
>> > +         This driver adds support for coarse (on or off) fan control
>> > +         and the keyboard backlight for newer Samsung laptops.
>> > +
>> >  config MXM_WMI
>> >         tristate "WMI support for MXM Laptop Graphics"
>> >         depends on ACPI_WMI
>> > diff --git a/drivers/platform/x86/Makefile
>> > b/drivers/platform/x86/Makefile
>> > index f82232b..4c65e51 100644
>> > --- a/drivers/platform/x86/Makefile
>> > +++ b/drivers/platform/x86/Makefile
>> > @@ -48,6 +48,7 @@ obj-$(CONFIG_XO1_RFKILL)      += xo1-rfkill.o
>> >  obj-$(CONFIG_XO15_EBOOK)       += xo15-ebook.o
>> >  obj-$(CONFIG_IBM_RTL)          += ibm_rtl.o
>> >  obj-$(CONFIG_SAMSUNG_LAPTOP)   += samsung-laptop.o
>> > +obj-$(CONFIG_SAMSUNG_WMI)      += samsung-wmi.o
>> >  obj-$(CONFIG_MXM_WMI)          += mxm-wmi.o
>> >  obj-$(CONFIG_INTEL_MID_POWER_BUTTON)   += intel_mid_powerbtn.o
>> >  obj-$(CONFIG_INTEL_OAKTRAIL)   += intel_oaktrail.o
>> > diff --git a/drivers/platform/x86/samsung-wmi.c
>> > b/drivers/platform/x86/samsung-wmi.c
>> > new file mode 100644
>> > index 0000000..c93cfe4
>> > --- /dev/null
>> > +++ b/drivers/platform/x86/samsung-wmi.c
>> > @@ -0,0 +1,221 @@
>> > +/*
>> > + *  Samsung WMI driver
>> > + *
>> > + *  Copyright (C) 2015 Gavin Li <git@thegavinli.com>
>> > + *
>> > + *  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, write to the Free Software Foundation,
>> > Inc.,
>> > + *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
>> > + */
>> > +
>> > +#include <linux/init.h>
>> > +#include <linux/module.h>
>> > +#include <linux/acpi.h>
>> > +#include <linux/leds.h>
>> > +#include <linux/platform_device.h>
>> > +
>> > +#define DRIVER_NAME "samsung-wmi"
>> > +#define WMI_GUID "C16C47BA-50E3-444A-AF3A-B1C348380001"
>> > +
>> > +struct samsung_wmi_packet {
>> > +       uint16_t magic;
>> > +       uint16_t opcode;
>> > +       uint8_t reqres;
>> > +       uint8_t data[16];
>> > +} __packed;
>> > +
>> > +static struct platform_device *samsung_wmi_device;
>> > +
>> > +static inline bool string_matches(const char *str, const char *kwd) {
>> > +       size_t len = strlen(kwd);
>> > +       if (strncmp(str, kwd, len) != 0)
>> > +               return false;
>> > +       return str[len] == '\0' || str[len] == '\n';
>> > +}
>> > +
>> > +static int samsung_wmi_method_call(uint16_t opcode, void *data, size_t
>> > len) {
>> > +       struct samsung_wmi_packet inpkt = {
>> > +               .magic = 0x5843,
>>
>> Please use a constant instead of a magic number here.
>>
>> > +               .opcode = opcode,
>> > +       };
>> > +       struct acpi_buffer inbuf = { sizeof(inpkt), &inpkt };
>> > +       struct acpi_buffer outbuf = { ACPI_ALLOCATE_BUFFER, NULL };
>> > +       union acpi_object *outobj;
>> > +       struct samsung_wmi_packet *outpkt;
>> > +       acpi_status st;
>> > +       int ret = -EIO;
>> > +       /********/
>> > +       if (len > 16) {
>>
>> Please use a constant instead of 16 here.
>>
>> > +               ret = -EINVAL;
>> > +               goto err0;
>> > +       }
>> > +       memcpy(inpkt.data, data, len);
>> > +       st = wmi_evaluate_method(WMI_GUID, 1, 0, &inbuf, &outbuf);
>> > +       if (ACPI_FAILURE(st)) {
>> > +               dev_err(&samsung_wmi_device->dev, "opcode 0x%x failed:
>> > %s\n",
>> > +                               opcode, acpi_format_exception(st));
>> > +               goto err0;
>> > +       }
>> > +       outobj = outbuf.pointer;
>> > +       if (outobj->type != ACPI_TYPE_BUFFER) {
>> > +               goto err1;
>> > +       }
>> > +       if (outobj->buffer.length < sizeof(outpkt)) {
>> > +               goto err1;
>> > +       }
>> > +       outpkt = (struct samsung_wmi_packet *)outobj->buffer.pointer;
>> > +       memcpy(data, outpkt->data, len);
>> > +       ret = 0;
>> > +err1:
>> > +       kfree(outobj);
>> > +err0:
>> > +       return ret;
>> > +}
>> > +
>> > +static int samsung_wmi_method_call_with_unlock(
>> > +               uint16_t unlock_opcode,
>> > +               uint16_t opcode, void *data, size_t len) {
>> > +       unsigned int unlock_data = 0xAABB;
>>
>> Same
>>
>> > +       int ret;
>> > +       /********/
>> > +       ret = samsung_wmi_method_call(unlock_opcode, &unlock_data,
>> > sizeof(unlock_data));
>> > +       if (ret)
>> > +               goto err0;
>> > +       if (unlock_data != 0xCCDD) {
>> > +               dev_err(&samsung_wmi_device->dev, "incorrect unlock
>> > response!\n");
>> > +               ret = -EIO;
>> > +               goto err0;
>> > +       }
>> > +       ret = samsung_wmi_method_call(opcode, data, len);
>> > +err0:
>> > +       return ret;
>> > +}
>> > +
>> > +static ssize_t samsung_wmi_fan_mode_show(struct device *dev, struct
>> > device_attribute *attr,
>> > +               char *buf) {
>> > +       uint32_t data = 0;
>> > +       if (samsung_wmi_method_call_with_unlock(0x31, 0x31, &data,
>> > sizeof(data)))
>> > +               return -EIO;
>> > +       if (data)
>> > +               strcpy(buf, "[auto off] on\n");
>> > +       else
>> > +               strcpy(buf, "auto off [on]\n");
>> > +       return strlen(buf);
>> > +}
>> > +
>> > +static ssize_t samsung_wmi_fan_mode_store(struct device *dev, struct
>> > device_attribute *attr,
>> > +               const char *buf, size_t count) {
>> > +       uint32_t data;
>> > +       if (string_matches(buf, "auto"))
>> > +               data = 0x810001;
>>
>> Same, and other places
>>
>> > +       else if (string_matches(buf, "on"))
>> > +               data = 0;
>> > +       else if (string_matches(buf, "off"))
>> > +               data = 0x800001;
>> > +       else
>> > +               return -EINVAL;
>> > +       if (samsung_wmi_method_call_with_unlock(0x31, 0x32, &data,
>> > sizeof(data)))
>> > +               return -EIO;
>> > +       else
>> > +               return count;
>> > +}
>> > +
>> > +static void samsung_wmi_kbd_backlight_led_brightness_set(
>> > +               struct led_classdev *cdev, enum led_brightness
>> > brightness) {
>> > +       unsigned int data = brightness;
>>
>> Why sometime uint32_t and sometime unsigned int ?
>>
>> > +       if (data > 4)
>> > +               data = 4;
>> > +       data = (data << 8) | 0x82;
>> > +       /********/
>> > +       samsung_wmi_method_call_with_unlock(0x78, 0x78, &data,
>> > sizeof(data));
>> > +}
>> > +
>> > +static DEVICE_ATTR(fan_mode, S_IRUGO | S_IWUSR,
>> > samsung_wmi_fan_mode_show, samsung_wmi_fan_mode_store);
>> > +
>> > +static struct platform_driver samsung_wmi_driver = {
>> > +       .driver = {
>> > +               .name = DRIVER_NAME,
>> > +               .owner = THIS_MODULE,
>> > +       },
>> > +};
>> > +
>> > +static struct led_classdev samsung_wmi_kbd_backlight_led = {
>> > +       .name = DRIVER_NAME "::kbd_backlight",
>> > +       .max_brightness = 4,
>> > +       .brightness_set = samsung_wmi_kbd_backlight_led_brightness_set,
>> > +};
>> > +
>> > +static int kb_default_brightness = -1;
>> > +module_param(kb_default_brightness, int, S_IRUGO);
>> > +MODULE_PARM_DESC(kb_default_brightness,
>> > +               "Default keyboard backlight brightness right after
>> > initialization");
>> > +
>> > +static int samsung_wmi_init(void) {
>> > +       int ret;
>> > +       // check whether method is present
>> > +       if (!wmi_has_guid(WMI_GUID))
>> > +               return -ENODEV;
>> > +       // we're good to go
>> > +       ret = platform_driver_register(&samsung_wmi_driver);
>> > +       if (ret) {
>> > +               goto err0;
>> > +       }
>> > +       samsung_wmi_device = platform_device_alloc(DRIVER_NAME, -1);
>> > +       if (!samsung_wmi_device) {
>> > +               ret = -ENOMEM;
>> > +               goto err1;
>> > +       }
>> > +       ret = platform_device_add(samsung_wmi_device);
>> > +       if (ret) {
>> > +               goto err2;
>> > +       }
>> > +       ret = device_create_file(&samsung_wmi_device->dev,
>> > &dev_attr_fan_mode);
>> > +       if (ret) {
>> > +               goto err3;
>> > +       }
>> > +       ret = led_classdev_register(&samsung_wmi_device->dev,
>> > +                       &samsung_wmi_kbd_backlight_led);
>> > +       if (ret) {
>> > +               goto err4;
>> > +       }
>> > +       if (kb_default_brightness >= 0) {
>> > +               led_set_brightness(&samsung_wmi_kbd_backlight_led,
>> > kb_default_brightness);
>> > +       }
>> > +       return 0;
>> > +//err5:
>> > +       led_classdev_unregister(&samsung_wmi_kbd_backlight_led);
>> > +err4:
>>
>> Instead of 'errX' please give a name related to what happen after the
>> label (or what failed just before)
>>
>> > +       device_remove_file(&samsung_wmi_device->dev,
>> > &dev_attr_fan_mode);
>> > +err3:
>> > +       platform_device_del(samsung_wmi_device);
>> > +err2:
>> > +       platform_device_put(samsung_wmi_device);
>> > +err1:
>> > +       platform_driver_unregister(&samsung_wmi_driver);
>> > +err0:
>> > +       return ret;
>> > +}
>> > +
>> > +static void samsung_wmi_exit(void) {
>> > +       led_classdev_unregister(&samsung_wmi_kbd_backlight_led);
>> > +       device_remove_file(&samsung_wmi_device->dev,
>> > &dev_attr_fan_mode);
>> > +       platform_device_unregister(samsung_wmi_device);
>> > +       platform_driver_unregister(&samsung_wmi_driver);
>> > +}
>> > +
>> > +MODULE_LICENSE("GPL");
>> > +MODULE_AUTHOR("Gavin Li");
>> > +MODULE_DESCRIPTION("WMI driver for some Samsung laptops.");
>> > +MODULE_ALIAS("wmi:" WMI_GUID);
>> > +module_init(samsung_wmi_init);
>> > +module_exit(samsung_wmi_exit);
>> > --
>> > 2.3.5
>> >
>> > --
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>> > More majordomo info at  http://vger.kernel.org/majordomo-info.html
>>
>>
>>
>> --
>> Corentin Chary
>> http://xf.iksaif.net
>
>