ACPI: x86: Add PNP_UART1_SKIP quirk for Lenovo Blade2 tablets

The x86 Android tablets on which quirks to skip looking for a matching
UartSerialBus resource and instead unconditionally create a serial bus
device (serdev) are necessary there are 2 sorts of serialports:

ACPI enumerated highspeed designware UARTs, these are the ones which
typcially need to be skipped since they need a serdev for the attached
BT HCI.

A PNP enumerated UART which is part of the PCU. So far the existing
quirks have ignored this. But on the Lenovo Yoga Tablet 2 Pro 1380
models this is used for a custom fastcharging protocol. There is
a Micro USB switch which can switch the USB data lines to this uart
and then a 600 baud protocol is used to configure the charger for
a voltage higher then 5V.

Add a new ACPI_QUIRK_PNP_UART1_SKIP quirk type and set this for
the existing entry for the Lenovo Yoga Tablet 2 830 / 1050 models.
Note this will lead to unnecessarily also creating a serdev for
the PCU UART on the 830 / 1050 which don't need this, but the UART
is not used otherwise there so that is not a problem.

Signed-off-by: Hans de Goede <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>

diff --git a/drivers/acpi/x86/utils.c b/drivers/acpi/x86/utils.c
index c7af2d2986fd0128a3f89c15e417161843ed0fc2..7dca73417e2bf5236977a415b66fb2fe35fa44ef 100644 (file)
--- a/drivers/acpi/x86/utils.c
+++ b/drivers/acpi/x86/utils.c
@@ -269,9 +269,10 @@ bool force_storage_d3(void)
 #define ACPI_QUIRK_SKIP_I2C_CLIENTS                            BIT(0)
 #define ACPI_QUIRK_UART1_SKIP                                  BIT(1)
 #define ACPI_QUIRK_UART1_TTY_UART2_SKIP                                BIT(2)
-#define ACPI_QUIRK_SKIP_ACPI_AC_AND_BATTERY                    BIT(3)
-#define ACPI_QUIRK_USE_ACPI_AC_AND_BATTERY                     BIT(4)
-#define ACPI_QUIRK_SKIP_GPIO_EVENT_HANDLERS                    BIT(5)
+#define ACPI_QUIRK_PNP_UART1_SKIP                              BIT(3)
+#define ACPI_QUIRK_SKIP_ACPI_AC_AND_BATTERY                    BIT(4)
+#define ACPI_QUIRK_USE_ACPI_AC_AND_BATTERY                     BIT(5)
+#define ACPI_QUIRK_SKIP_GPIO_EVENT_HANDLERS                    BIT(6)
 
 static const struct dmi_system_id acpi_quirk_skip_dmi_ids[] = {
        /*
@@ -351,6 +352,7 @@ static const struct dmi_system_id acpi_quirk_skip_dmi_ids[] = {
                        DMI_MATCH(DMI_BIOS_VERSION, "BLADE_21"),
                },
                .driver_data = (void *)(ACPI_QUIRK_SKIP_I2C_CLIENTS |
+                                       ACPI_QUIRK_PNP_UART1_SKIP |
                                        ACPI_QUIRK_SKIP_ACPI_AC_AND_BATTERY),
        },
        {
@@ -449,14 +451,18 @@ static int acpi_dmi_skip_serdev_enumeration(struct device *controller_parent, bo
        if (ret)
                return 0;
 
-       /* to not match on PNP enumerated debug UARTs */
-       if (!dev_is_platform(controller_parent))
-               return 0;
-
        dmi_id = dmi_first_match(acpi_quirk_skip_dmi_ids);
        if (dmi_id)
                quirks = (unsigned long)dmi_id->driver_data;
 
+       if (!dev_is_platform(controller_parent)) {
+               /* PNP enumerated UARTs */
+               if ((quirks & ACPI_QUIRK_PNP_UART1_SKIP) && uid == 1)
+                       *skip = true;
+
+               return 0;
+       }
+
        if ((quirks & ACPI_QUIRK_UART1_SKIP) && uid == 1)
                *skip = true;