Re: [PATCH v5] platform/x86/fujitsu-laptop: Add battery charge control support

Jonathan Woithe
2024-02-27T22:11:51Z

On Tue, Feb 27, 2024 at 12:05:45PM +0000, Szilard Fabian wrote:
> This patch adds battery charge control support on Fujitsu notebooks
> via the S006 method of the FUJ02E3 ACPI device. With this method it's
> possible to set charge_control_end_threshold between 50 and 100%.
>
> Tested on Lifebook E5411 and Lifebook U728. Sadly I can't test this
> patch on a dual battery one, but I didn't find any clue about
> independent battery charge control on dual battery Fujitsu notebooks
> either. And by that I mean checking the DSDT table of various Lifebook
> notebooks and reverse engineering FUJ02E3.dll.
>
> Signed-off-by: Szilard Fabian <szfabian@bluemarch.art>

Acked-by: Jonathan Woithe <jwoithe@just42.net>

> v5:
> * add ACPI_BATTERY dependency into Kconfig
>
> v4:
> * formatting fixes
> * replaced sprintf() with sysfs_emit()
>
> v3:
> * added additional error handling
> * removed if statement with device_create_file(), just returning that
> function instead
> * added bool charge_control_supported into struct fujitsu_laptop
> * added a 'charge_control_add' and 'charge_control_remove' function to be
> called from acpi_fujitsu_laptop_add() and acpi_fujitsu_laptop_remove()
> * moved FUJ02E3 S006 probing logic from the ACPI battery hooks to the new
> 'charge_control_*' functions
>
> v2:
> Forgot to sign-off the original commit. Fixed, sorry for the
> inconvenience.
> ---
> drivers/platform/x86/Kconfig | 1 +
> drivers/platform/x86/fujitsu-laptop.c | 125 ++++++++++++++++++++++++++
> 2 files changed, 126 insertions(+)
>
> diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
> index bdd302274b9a..945295f98560 100644
> --- a/drivers/platform/x86/Kconfig
> +++ b/drivers/platform/x86/Kconfig
> @@ -374,6 +374,7 @@ config FUJITSU_LAPTOP
> depends on ACPI
> depends on INPUT
> depends on BACKLIGHT_CLASS_DEVICE
> + depends on ACPI_BATTERY
> depends on ACPI_VIDEO || ACPI_VIDEO = n
> select INPUT_SPARSEKMAP
> select NEW_LEDS
> diff --git a/drivers/platform/x86/fujitsu-laptop.c b/drivers/platform/x86/fujitsu-laptop.c
> index 085e044e888e..69f9730bb14a 100644
> --- a/drivers/platform/x86/fujitsu-laptop.c
> +++ b/drivers/platform/x86/fujitsu-laptop.c
> @@ -49,6 +49,8 @@
> #include <linux/kfifo.h>
> #include <linux/leds.h>
> #include <linux/platform_device.h>
> +#include <linux/power_supply.h>
> +#include <acpi/battery.h>
> #include <acpi/video.h>
>
> #define FUJITSU_DRIVER_VERSION "0.6.0"
> @@ -97,6 +99,10 @@
> #define BACKLIGHT_OFF (BIT(0) | BIT(1))
> #define BACKLIGHT_ON 0
>
> +/* FUNC interface - battery control interface */
> +#define FUNC_S006_METHOD 0x1006
> +#define CHARGE_CONTROL_RW 0x21
> +
> /* Scancodes read from the GIRB register */
> #define KEY1_CODE 0x410
> #define KEY2_CODE 0x411
> @@ -132,6 +138,7 @@ struct fujitsu_laptop {
> spinlock_t fifo_lock;
> int flags_supported;
> int flags_state;
> + bool charge_control_supported;
> };
>
> static struct acpi_device *fext;
> @@ -164,6 +171,118 @@ static int call_fext_func(struct acpi_device *device,
> return value;
> }
>
> +/* Battery charge control code */
> +static ssize_t charge_control_end_threshold_store(struct device *dev,
> + struct device_attribute *attr,
> + const char *buf, size_t count)
> +{
> + int value, ret;
> +
> + ret = kstrtouint(buf, 10, &value);
> + if (ret)
> + return ret;
> +
> + if (value < 50 || value > 100)
> + return -EINVAL;
> +
> + int cc_end_value, s006_cc_return;
> +
> + cc_end_value = value * 0x100 + 0x20;
> + s006_cc_return = call_fext_func(fext, FUNC_S006_METHOD,
> + CHARGE_CONTROL_RW, cc_end_value, 0x0);
> +
> + if (s006_cc_return < 0)
> + return s006_cc_return;
> +
> + /*
> + * The S006 0x21 method returns 0x00 in case the provided value
> + * is invalid.
> + */
> + if (s006_cc_return == 0x00)
> + return -EINVAL;
> +
> + return count;
> +}
> +
> +static ssize_t charge_control_end_threshold_show(struct device *dev,
> + struct device_attribute *attr,
> + char *buf)
> +{
> + int status;
> +
> + status = call_fext_func(fext, FUNC_S006_METHOD,
> + CHARGE_CONTROL_RW, 0x21, 0x0);
> +
> + if (status < 0)
> + return status;
> +
> + return sysfs_emit(buf, "%d\n", status);
> +}
> +
> +static DEVICE_ATTR_RW(charge_control_end_threshold);
> +
> +/* ACPI battery hook */
> +static int fujitsu_battery_add_hook(struct power_supply *battery,
> + struct acpi_battery_hook *hook)
> +{
> + return device_create_file(&battery->dev,
> + &dev_attr_charge_control_end_threshold);
> +}
> +
> +static int fujitsu_battery_remove_hook(struct power_supply *battery,
> + struct acpi_battery_hook *hook)
> +{
> + device_remove_file(&battery->dev,
> + &dev_attr_charge_control_end_threshold);
> +
> + return 0;
> +}
> +
> +static struct acpi_battery_hook battery_hook = {
> + .add_battery = fujitsu_battery_add_hook,
> + .remove_battery = fujitsu_battery_remove_hook,
> + .name = "Fujitsu Battery Extension",
> +};
> +
> +/*
> + * These functions are intended to be called from acpi_fujitsu_laptop_add and
> + * acpi_fujitsu_laptop_remove.
> + */
> +static int fujitsu_battery_charge_control_add(struct acpi_device *device)
> +{
> + struct fujitsu_laptop *priv = acpi_driver_data(device);
> +
> + priv->charge_control_supported = false;
> +
> + /*
> + * Check if the S006 0x21 method exists by trying to get the current
> + * battery charge limit.
> + */
> + int s006_cc_return;
> +
> + s006_cc_return = call_fext_func(fext, FUNC_S006_METHOD,
> + CHARGE_CONTROL_RW, 0x21, 0x0);
> +
> + if (s006_cc_return < 0)
> + return s006_cc_return;
> +
> + if (s006_cc_return == UNSUPPORTED_CMD)
> + return -ENODEV;
> +
> + priv->charge_control_supported = true;
> + battery_hook_register(&battery_hook);
> +
> + return 0;
> +}
> +
> +static void fujitsu_battery_charge_control_remove(struct acpi_device *device)
> +{
> + struct fujitsu_laptop *priv = acpi_driver_data(device);
> +
> + if (priv->charge_control_supported)
> + battery_hook_unregister(&battery_hook);
> +}
> +
> /* Hardware access for LCD brightness control */
>
> static int set_lcd_level(struct acpi_device *device, int level)
> @@ -839,6 +958,10 @@ static int acpi_fujitsu_laptop_add(struct acpi_device *device)
> if (ret)
> goto err_free_fifo;
>
> + ret = fujitsu_battery_charge_control_add(device);
> + if (ret < 0)
> + pr_warn("Unable to register battery charge control: %d\n", ret);
> +
> return 0;
>
> err_free_fifo:
> @@ -851,6 +974,8 @@ static void acpi_fujitsu_laptop_remove(struct acpi_device *device)
> {
> struct fujitsu_laptop *priv = acpi_driver_data(device);
>
> + fujitsu_battery_charge_control_remove(device);
> +
> fujitsu_laptop_platform_remove(device);
>
> kfifo_free(&priv->fifo);
> --
> 2.44.0
>
>