diff options
| -rw-r--r-- | Documentation/admin-guide/laptops/thinkpad-acpi.rst | 24 | ||||
| -rw-r--r-- | drivers/platform/x86/lenovo/thinkpad_acpi.c | 117 |
2 files changed, 141 insertions, 0 deletions
diff --git a/Documentation/admin-guide/laptops/thinkpad-acpi.rst b/Documentation/admin-guide/laptops/thinkpad-acpi.rst index f874db31801d..db4588af0278 100644 --- a/Documentation/admin-guide/laptops/thinkpad-acpi.rst +++ b/Documentation/admin-guide/laptops/thinkpad-acpi.rst @@ -1543,6 +1543,30 @@ Values: This setting can also be toggled via the Fn+doubletap hotkey. +USB-C Security +-------------- + +sysfs: usb_c_security + +Reports the current state of the USB-C Security (Restricted Mode) feature +on supported ThinkPad systems. When enabled, USB-C data connections are +disabled while power delivery is preserved. + +The available command is:: + + cat /sys/devices/platform/thinkpad_acpi/usb_c_security + +Values: + + * ``enabled`` - USB-C data connections are currently blocked + * ``disabled`` - USB-C data connections are currently allowed + +The attribute is read-only. The USB-C Security state can only be toggled +via the Fn+U followed by Fn+S hotkey chord. + +The sysfs attribute is not created on platforms that do not support this +feature. + Auxmac ------ diff --git a/drivers/platform/x86/lenovo/thinkpad_acpi.c b/drivers/platform/x86/lenovo/thinkpad_acpi.c index f614b2701d48..6dd7c28fc0db 100644 --- a/drivers/platform/x86/lenovo/thinkpad_acpi.c +++ b/drivers/platform/x86/lenovo/thinkpad_acpi.c @@ -38,6 +38,7 @@ #include <linux/backlight.h> #include <linux/bitfield.h> #include <linux/bitops.h> +#include <linux/cleanup.h> #include <linux/debugfs.h> #include <linux/delay.h> #include <linux/dmi.h> @@ -67,6 +68,7 @@ #include <linux/seq_file.h> #include <linux/slab.h> #include <linux/string.h> +#include <linux/string_choices.h> #include <linux/string_helpers.h> #include <linux/sysfs.h> #include <linux/types.h> @@ -186,6 +188,7 @@ enum tpacpi_hkey_event_t { TP_HKEY_EV_AMT_TOGGLE = 0x131a, /* Toggle AMT on/off */ TP_HKEY_EV_CAMERASHUTTER_TOGGLE = 0x131b, /* Toggle Camera Shutter */ TP_HKEY_EV_DOUBLETAP_TOGGLE = 0x131c, /* Toggle trackpoint doubletap on/off */ + TP_HKEY_EV_USB_C_SECURITY = 0x131e, /* USB C Security (Fn+U, Fn+S) */ TP_HKEY_EV_PROFILE_TOGGLE = 0x131f, /* Toggle platform profile in 2024 systems */ TP_HKEY_EV_PROFILE_TOGGLE2 = 0x1401, /* Toggle platform profile in 2025 + systems */ @@ -375,6 +378,8 @@ static struct { u32 has_adaptive_kbd:1; u32 kbd_lang:1; u32 trackpoint_doubletap_enable:1; + u32 usbc_security_supported:1; + bool usbc_security_enabled; struct quirk_entry *quirks; } tp_features; @@ -11285,6 +11290,111 @@ static struct ibm_struct hwdd_driver_data = { .name = "hwdd", }; +/************************************************************************* + * USB-C Security subdriver + * + * HKEY.USCS(0) is a read-only ACPI method; its argument is ignored. + * It always returns: + * bit 16 - USB-C security capability present on this SKU or not + * bit 0 - USB-C Security state (enable or disable) + * + * Hotkey + * ------ + * 0x131e (Fn+U, Fn+S): firmware toggles USBS before firing the event. + * The driver reads back the new state and notifies the sysfs attribute. + */ + +/* USCS() return word bit layout */ +#define USCS_CAP_BIT BIT(16) /* capability: feature present on SKU */ +#define USCS_STATUS_BIT BIT(0) /* current security state */ + +/* Protects USCS() ACPI method calls in usbc_security_query() */ +static DEFINE_MUTEX(usbc_security_mutex); + +/** + * usbc_security_query - read current USB-C security state via USCS() + * @enabled: out - true when security is ON (data connections blocked) + * + * Returns: + * 0 success, @enabled contains the current state + * -EIO ACPI evaluation failed + * -ENODEV capability bit absent; feature not present on this SKU* + */ +static int usbc_security_query(bool *enabled) +{ + int status; + + guard(mutex)(&usbc_security_mutex); + if (!acpi_evalf(hkey_handle, &status, "USCS", "dd", 0)) + return -EIO; + + if (!(status & USCS_CAP_BIT)) { + pr_debug("USCS cap bit absent (raw=0x%x)\n", status); + return -ENODEV; + } + + *enabled = status & USCS_STATUS_BIT; + return 0; +} + +/* sysfs: /sys/devices/platform/thinkpad_acpi/usb_c_security ---------- */ +static ssize_t usb_c_security_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + return sysfs_emit(buf, "%s\n", + str_enabled_disabled(tp_features.usbc_security_enabled)); +} + +static DEVICE_ATTR_RO(usb_c_security); + +static struct attribute *usbc_security_attributes[] = { + &dev_attr_usb_c_security.attr, + NULL, +}; + +static umode_t usbc_security_attr_is_visible(struct kobject *kobj, + struct attribute *attr, int n) +{ + return tp_features.usbc_security_supported ? attr->mode : 0; +} + +static const struct attribute_group usbc_security_attr_group = { + .is_visible = usbc_security_attr_is_visible, + .attrs = usbc_security_attributes, +}; + +static int tpacpi_usbc_security_init(struct ibm_init_struct *iibm) +{ + int err; + + err = usbc_security_query(&tp_features.usbc_security_enabled); + if (err == -ENODEV) + return 0; + if (err) + return err; + + tp_features.usbc_security_supported = true; + return 0; +} + +/* tpacpi_usbc_security_hotkey - handle Fn+U Fn+S hotkey (0x131e) */ +static bool tpacpi_usbc_security_hotkey(void) +{ + if (!tp_features.usbc_security_supported) + return false; + + if (usbc_security_query(&tp_features.usbc_security_enabled)) + return false; + + sysfs_notify(&tpacpi_pdev->dev.kobj, NULL, "usb_c_security"); + return true; +} + +static struct ibm_struct usbc_security_driver_data = { + .name = "usbc_security", +}; + /* --------------------------------------------------------------------- */ static struct attribute *tpacpi_driver_attributes[] = { @@ -11345,6 +11455,7 @@ static const struct attribute_group *tpacpi_groups[] = { &dprc_attr_group, &auxmac_attr_group, &hwdd_attr_group, + &usbc_security_attr_group, NULL, }; @@ -11499,6 +11610,8 @@ static bool tpacpi_driver_event(const unsigned int hkey_event) case TP_HKEY_EV_PROFILE_TOGGLE2: platform_profile_cycle(); return true; + case TP_HKEY_EV_USB_C_SECURITY: + return tpacpi_usbc_security_hotkey(); } return false; @@ -11964,6 +12077,10 @@ static struct ibm_init_struct ibms_init[] __initdata = { .init = tpacpi_hwdd_init, .data = &hwdd_driver_data, }, + { + .init = tpacpi_usbc_security_init, + .data = &usbc_security_driver_data, + }, }; static int __init set_ibm_param(const char *val, const struct kernel_param *kp) |