platform/x86: hp-wmi: Fix SW_TABLET_MODE detection method

The purpose of this patch is to introduce a fix and removal of the
current hack when determining tablet mode status.

Determining the tablet mode status requires reading Byte 0 bit 2 as
reported by HPWMI_HARDWARE_QUERY.  The investigation identified the
failure was rooted in two areas: HPWMI_HARDWARE_QUERY failure (0x05)
and reading Byte 0, bit 2 only to determine the table mode status.
HPWMI_HARDWARE_QUERY WMI failure also rendered the dock state value
invalid.

The latest changes use SMBIOS Type 3 (chassis type) and WMI Command
0x40 (device_mode_status) information to determine if the device is
in tablet mode or not.

hp_wmi_hw_state function was split into two functions;
hp_wmi_get_dock_state and hp_wmi_get_tablet_mode.  The new functions
separate how dock_state and tablet_mode is handled in a cleaner
manner.

All changes were validated on a HP ZBook Workstation notebook,
HP EliteBook x360, and HP EliteBook 850 G8.

Signed-off-by: Jorge Lopez <jorge.lopez2@hp.com>
Link: https://lore.kernel.org/r/20220310210853.28367-3-jorge.lopez2@hp.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

diff --git a/drivers/platform/x86/hp-wmi.c b/drivers/platform/x86/hp-wmi.c
index 103f563..1605927 100644 (file)
--- a/drivers/platform/x86/hp-wmi.c
+++ b/drivers/platform/x86/hp-wmi.c
@@ -35,10 +35,6 @@ MODULE_LICENSE("GPL");
 MODULE_ALIAS("wmi:95F24279-4D7B-4334-9387-ACCDC67EF61C");
 MODULE_ALIAS("wmi:5FB7F034-2C63-45e9-BE91-3D44E2C707E4");
 
-static int enable_tablet_mode_sw = -1;
-module_param(enable_tablet_mode_sw, int, 0444);
-MODULE_PARM_DESC(enable_tablet_mode_sw, "Enable SW_TABLET_MODE reporting (-1=auto, 0=no, 1=yes)");
-
 #define HPWMI_EVENT_GUID "95F24279-4D7B-4334-9387-ACCDC67EF61C"
 #define HPWMI_BIOS_GUID "5FB7F034-2C63-45e9-BE91-3D44E2C707E4"
 #define HP_OMEN_EC_THERMAL_PROFILE_OFFSET 0x95
@@ -107,6 +103,7 @@ enum hp_wmi_commandtype {
        HPWMI_FEATURE2_QUERY            = 0x0d,
        HPWMI_WIRELESS2_QUERY           = 0x1b,
        HPWMI_POSTCODEERROR_QUERY       = 0x2a,
+       HPWMI_SYSTEM_DEVICE_MODE        = 0x40,
        HPWMI_THERMAL_PROFILE_QUERY     = 0x4c,
 };
 
@@ -217,6 +214,19 @@ struct rfkill2_device {
 static int rfkill2_count;
 static struct rfkill2_device rfkill2[HPWMI_MAX_RFKILL2_DEVICES];
 
+/*
+ * Chassis Types values were obtained from SMBIOS reference
+ * specification version 3.00. A complete list of system enclosures
+ * and chassis types is available on Table 17.
+ */
+static const char * const tablet_chassis_types[] = {
+       "30", /* Tablet*/
+       "31", /* Convertible */
+       "32"  /* Detachable */
+};
+
+#define DEVICE_MODE_TABLET     0x06
+
 /* map output size to the corresponding WMI method id */
 static inline int encode_outsize_for_pvsz(int outsize)
 {
@@ -345,14 +355,39 @@ static int hp_wmi_read_int(int query)
        return val;
 }
 
-static int hp_wmi_hw_state(int mask)
+static int hp_wmi_get_dock_state(void)
 {
        int state = hp_wmi_read_int(HPWMI_HARDWARE_QUERY);
 
        if (state < 0)
                return state;
 
-       return !!(state & mask);
+       return !!(state & HPWMI_DOCK_MASK);
+}
+
+static int hp_wmi_get_tablet_mode(void)
+{
+       char system_device_mode[4] = { 0 };
+       const char *chassis_type;
+       bool tablet_found;
+       int ret;
+
+       chassis_type = dmi_get_system_info(DMI_CHASSIS_TYPE);
+       if (!chassis_type)
+               return -ENODEV;
+
+       tablet_found = match_string(tablet_chassis_types,
+                                   ARRAY_SIZE(tablet_chassis_types),
+                                   chassis_type) >= 0;
+       if (!tablet_found)
+               return -ENODEV;
+
+       ret = hp_wmi_perform_query(HPWMI_SYSTEM_DEVICE_MODE, HPWMI_READ,
+                                  system_device_mode, 0, sizeof(system_device_mode));
+       if (ret < 0)
+               return ret;
+
+       return system_device_mode[0] == DEVICE_MODE_TABLET;
 }
 
 static int omen_thermal_profile_set(int mode)
@@ -568,7 +603,7 @@ static ssize_t als_show(struct device *dev, struct device_attribute *attr,
 static ssize_t dock_show(struct device *dev, struct device_attribute *attr,
                         char *buf)
 {
-       int value = hp_wmi_hw_state(HPWMI_DOCK_MASK);
+       int value = hp_wmi_get_dock_state();
        if (value < 0)
                return value;
        return sprintf(buf, "%d\n", value);
@@ -577,7 +612,7 @@ static ssize_t dock_show(struct device *dev, struct device_attribute *attr,
 static ssize_t tablet_show(struct device *dev, struct device_attribute *attr,
                           char *buf)
 {
-       int value = hp_wmi_hw_state(HPWMI_TABLET_MASK);
+       int value = hp_wmi_get_tablet_mode();
        if (value < 0)
                return value;
        return sprintf(buf, "%d\n", value);
@@ -699,10 +734,10 @@ static void hp_wmi_notify(u32 value, void *context)
        case HPWMI_DOCK_EVENT:
                if (test_bit(SW_DOCK, hp_wmi_input_dev->swbit))
                        input_report_switch(hp_wmi_input_dev, SW_DOCK,
-                                           hp_wmi_hw_state(HPWMI_DOCK_MASK));
+                                           hp_wmi_get_dock_state());
                if (test_bit(SW_TABLET_MODE, hp_wmi_input_dev->swbit))
                        input_report_switch(hp_wmi_input_dev, SW_TABLET_MODE,
-                                           hp_wmi_hw_state(HPWMI_TABLET_MASK));
+                                           hp_wmi_get_tablet_mode());
                input_sync(hp_wmi_input_dev);
                break;
        case HPWMI_PARK_HDD:
@@ -780,19 +815,17 @@ static int __init hp_wmi_input_setup(void)
        __set_bit(EV_SW, hp_wmi_input_dev->evbit);
 
        /* Dock */
-       val = hp_wmi_hw_state(HPWMI_DOCK_MASK);
+       val = hp_wmi_get_dock_state();
        if (!(val < 0)) {
                __set_bit(SW_DOCK, hp_wmi_input_dev->swbit);
                input_report_switch(hp_wmi_input_dev, SW_DOCK, val);
        }
 
        /* Tablet mode */
-       if (enable_tablet_mode_sw > 0) {
-               val = hp_wmi_hw_state(HPWMI_TABLET_MASK);
-               if (val >= 0) {
-                       __set_bit(SW_TABLET_MODE, hp_wmi_input_dev->swbit);
-                       input_report_switch(hp_wmi_input_dev, SW_TABLET_MODE, val);
-               }
+       val = hp_wmi_get_tablet_mode();
+       if (!(val < 0)) {
+               __set_bit(SW_TABLET_MODE, hp_wmi_input_dev->swbit);
+               input_report_switch(hp_wmi_input_dev, SW_TABLET_MODE, val);
        }
 
        err = sparse_keymap_setup(hp_wmi_input_dev, hp_wmi_keymap, NULL);
@@ -1227,10 +1260,10 @@ static int hp_wmi_resume_handler(struct device *device)
        if (hp_wmi_input_dev) {
                if (test_bit(SW_DOCK, hp_wmi_input_dev->swbit))
                        input_report_switch(hp_wmi_input_dev, SW_DOCK,
-                                           hp_wmi_hw_state(HPWMI_DOCK_MASK));
+                                           hp_wmi_get_dock_state());
                if (test_bit(SW_TABLET_MODE, hp_wmi_input_dev->swbit))
                        input_report_switch(hp_wmi_input_dev, SW_TABLET_MODE,
-                                           hp_wmi_hw_state(HPWMI_TABLET_MASK));
+                                           hp_wmi_get_tablet_mode());
                input_sync(hp_wmi_input_dev);
        }