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authorAlexander Schremmer <alex@alexanderweb.de>2019-08-22 14:48:33 +0300
committerAndy Shevchenko <andriy.shevchenko@linux.intel.com>2019-09-07 21:16:09 +0300
commit110ea1d833ad291272d52e0a40a06157a3d9ba17 (patch)
tree3acdf105f4d3b4d0b076092f3028f130d8cd3042 /drivers/platform
parentad0d315b4d4e7138f43acf03308192ec00e9614d (diff)
downloadlinux-110ea1d833ad291272d52e0a40a06157a3d9ba17.tar.xz
platform/x86: thinkpad_acpi: Add ThinkPad PrivacyGuard
This feature is found optionally in T480s, T490, T490s. The feature is called lcdshadow and visible via /proc/acpi/ibm/lcdshadow. The ACPI methods \_SB.PCI0.LPCB.EC.HKEY.{GSSS,SSSS,TSSS,CSSS} are available in these machines. They get, set, toggle or change the state apparently. The patch was tested on a 5.0 series kernel on a T480s. Signed-off-by: Alexander Schremmer <alex@alexanderweb.de> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Diffstat (limited to 'drivers/platform')
-rw-r--r--drivers/platform/x86/thinkpad_acpi.c105
1 files changed, 105 insertions, 0 deletions
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)