diff options
| -rw-r--r-- | Documentation/admin-guide/laptops/thinkpad-acpi.rst | 23 | ||||
| -rw-r--r-- | drivers/platform/x86/thinkpad_acpi.c | 105 |
2 files changed, 128 insertions, 0 deletions
diff --git a/Documentation/admin-guide/laptops/thinkpad-acpi.rst b/Documentation/admin-guide/laptops/thinkpad-acpi.rst index adea0bf2acc5..822907dcc845 100644 --- a/Documentation/admin-guide/laptops/thinkpad-acpi.rst +++ b/Documentation/admin-guide/laptops/thinkpad-acpi.rst @@ -49,6 +49,7 @@ detailed description): - Fan control and monitoring: fan speed, fan enable/disable - WAN enable and disable - UWB enable and disable + - LCD Shadow (PrivacyGuard) enable and disable A compatibility table by model and feature is maintained on the web site, http://ibm-acpi.sf.net/. I appreciate any success or failure @@ -1409,6 +1410,28 @@ Sysfs notes Documentation/driver-api/rfkill.rst for details. +LCD Shadow control +------------------ + +procfs: /proc/acpi/ibm/lcdshadow + +Some newer T480s and T490s ThinkPads provide a feature called +PrivacyGuard. By turning this feature on, the usable vertical and +horizontal viewing angles of the LCD can be limited (as if some privacy +screen was applied manually in front of the display). + +procfs notes +^^^^^^^^^^^^ + +The available commands are:: + + echo '0' >/proc/acpi/ibm/lcdshadow + echo '1' >/proc/acpi/ibm/lcdshadow + +The first command ensures the best viewing angle and the latter one turns +on the feature, restricting the viewing angles. + + EXPERIMENTAL: UWB ----------------- diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c index d379bdf98a0f..da794dcfdd92 100644 --- a/drivers/platform/x86/thinkpad_acpi.c +++ b/drivers/platform/x86/thinkpad_acpi.c @@ -9711,6 +9711,107 @@ static struct ibm_struct battery_driver_data = { .exit = tpacpi_battery_exit, }; +/************************************************************************* + * LCD Shadow subdriver, for the Lenovo PrivacyGuard feature + */ + +static int lcdshadow_state; + +static int lcdshadow_on_off(bool state) +{ + acpi_handle set_shadow_handle; + int output; + + if (ACPI_FAILURE(acpi_get_handle(hkey_handle, "SSSS", &set_shadow_handle))) { + pr_warn("Thinkpad ACPI has no %s interface.\n", "SSSS"); + return -EIO; + } + + if (!acpi_evalf(set_shadow_handle, &output, NULL, "dd", (int)state)) + return -EIO; + + lcdshadow_state = state; + return 0; +} + +static int lcdshadow_set(bool on) +{ + if (lcdshadow_state < 0) + return lcdshadow_state; + if (lcdshadow_state == on) + return 0; + return lcdshadow_on_off(on); +} + +static int tpacpi_lcdshadow_init(struct ibm_init_struct *iibm) +{ + acpi_handle get_shadow_handle; + int output; + + if (ACPI_FAILURE(acpi_get_handle(hkey_handle, "GSSS", &get_shadow_handle))) { + lcdshadow_state = -ENODEV; + return 0; + } + + if (!acpi_evalf(get_shadow_handle, &output, NULL, "dd", 0)) { + lcdshadow_state = -EIO; + return -EIO; + } + if (!(output & 0x10000)) { + lcdshadow_state = -ENODEV; + return 0; + } + lcdshadow_state = output & 0x1; + + return 0; +} + +static void lcdshadow_resume(void) +{ + if (lcdshadow_state >= 0) + lcdshadow_on_off(lcdshadow_state); +} + +static int lcdshadow_read(struct seq_file *m) +{ + if (lcdshadow_state < 0) { + seq_puts(m, "status:\t\tnot supported\n"); + } else { + seq_printf(m, "status:\t\t%d\n", lcdshadow_state); + seq_puts(m, "commands:\t0, 1\n"); + } + + return 0; +} + +static int lcdshadow_write(char *buf) +{ + char *cmd; + int state = -1; + + if (lcdshadow_state < 0) + return -ENODEV; + + while ((cmd = next_cmd(&buf))) { + if (strlencmp(cmd, "0") == 0) + state = 0; + else if (strlencmp(cmd, "1") == 0) + state = 1; + } + + if (state == -1) + return -EINVAL; + + return lcdshadow_set(state); +} + +static struct ibm_struct lcdshadow_driver_data = { + .name = "lcdshadow", + .resume = lcdshadow_resume, + .read = lcdshadow_read, + .write = lcdshadow_write, +}; + /**************************************************************************** **************************************************************************** * @@ -10192,6 +10293,10 @@ static struct ibm_init_struct ibms_init[] __initdata = { .init = tpacpi_battery_init, .data = &battery_driver_data, }, + { + .init = tpacpi_lcdshadow_init, + .data = &lcdshadow_driver_data, + }, }; static int __init set_ibm_param(const char *val, const struct kernel_param *kp) |