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-rw-r--r--include/linux/apple-gmux.h109
1 files changed, 107 insertions, 2 deletions
diff --git a/include/linux/apple-gmux.h b/include/linux/apple-gmux.h
index ddb10aa67b14..1f68b49bcd68 100644
--- a/include/linux/apple-gmux.h
+++ b/include/linux/apple-gmux.h
@@ -8,18 +8,118 @@
#define LINUX_APPLE_GMUX_H
#include <linux/acpi.h>
+#include <linux/io.h>
+#include <linux/pnp.h>
#define GMUX_ACPI_HID "APP000B"
+/*
+ * gmux port offsets. Many of these are not yet used, but may be in the
+ * future, and it's useful to have them documented here anyhow.
+ */
+#define GMUX_PORT_VERSION_MAJOR 0x04
+#define GMUX_PORT_VERSION_MINOR 0x05
+#define GMUX_PORT_VERSION_RELEASE 0x06
+#define GMUX_PORT_SWITCH_DISPLAY 0x10
+#define GMUX_PORT_SWITCH_GET_DISPLAY 0x11
+#define GMUX_PORT_INTERRUPT_ENABLE 0x14
+#define GMUX_PORT_INTERRUPT_STATUS 0x16
+#define GMUX_PORT_SWITCH_DDC 0x28
+#define GMUX_PORT_SWITCH_EXTERNAL 0x40
+#define GMUX_PORT_SWITCH_GET_EXTERNAL 0x41
+#define GMUX_PORT_DISCRETE_POWER 0x50
+#define GMUX_PORT_MAX_BRIGHTNESS 0x70
+#define GMUX_PORT_BRIGHTNESS 0x74
+#define GMUX_PORT_VALUE 0xc2
+#define GMUX_PORT_READ 0xd0
+#define GMUX_PORT_WRITE 0xd4
+
+#define GMUX_MIN_IO_LEN (GMUX_PORT_BRIGHTNESS + 4)
+
#if IS_ENABLED(CONFIG_APPLE_GMUX)
+static inline bool apple_gmux_is_indexed(unsigned long iostart)
+{
+ u16 val;
+
+ outb(0xaa, iostart + 0xcc);
+ outb(0x55, iostart + 0xcd);
+ outb(0x00, iostart + 0xce);
+
+ val = inb(iostart + 0xcc) | (inb(iostart + 0xcd) << 8);
+ if (val == 0x55aa)
+ return true;
+
+ return false;
+}
/**
- * apple_gmux_present() - detect if gmux is built into the machine
+ * apple_gmux_detect() - detect if gmux is built into the machine
+ *
+ * @pnp_dev: Device to probe or NULL to use the first matching device
+ * @indexed_ret: Returns (by reference) if the gmux is indexed or not
+ *
+ * Detect if a supported gmux device is present by actually probing it.
+ * This avoids the false positives returned on some models by
+ * apple_gmux_present().
+ *
+ * Return: %true if a supported gmux ACPI device is detected and the kernel
+ * was configured with CONFIG_APPLE_GMUX, %false otherwise.
+ */
+static inline bool apple_gmux_detect(struct pnp_dev *pnp_dev, bool *indexed_ret)
+{
+ u8 ver_major, ver_minor, ver_release;
+ struct device *dev = NULL;
+ struct acpi_device *adev;
+ struct resource *res;
+ bool indexed = false;
+ bool ret = false;
+
+ if (!pnp_dev) {
+ adev = acpi_dev_get_first_match_dev(GMUX_ACPI_HID, NULL, -1);
+ if (!adev)
+ return false;
+
+ dev = get_device(acpi_get_first_physical_node(adev));
+ acpi_dev_put(adev);
+ if (!dev)
+ return false;
+
+ pnp_dev = to_pnp_dev(dev);
+ }
+
+ res = pnp_get_resource(pnp_dev, IORESOURCE_IO, 0);
+ if (!res || resource_size(res) < GMUX_MIN_IO_LEN)
+ goto out;
+
+ /*
+ * Invalid version information may indicate either that the gmux
+ * device isn't present or that it's a new one that uses indexed io.
+ */
+ ver_major = inb(res->start + GMUX_PORT_VERSION_MAJOR);
+ ver_minor = inb(res->start + GMUX_PORT_VERSION_MINOR);
+ ver_release = inb(res->start + GMUX_PORT_VERSION_RELEASE);
+ if (ver_major == 0xff && ver_minor == 0xff && ver_release == 0xff) {
+ indexed = apple_gmux_is_indexed(res->start);
+ if (!indexed)
+ goto out;
+ }
+
+ if (indexed_ret)
+ *indexed_ret = indexed;
+
+ ret = true;
+out:
+ put_device(dev);
+ return ret;
+}
+
+/**
+ * apple_gmux_present() - check if gmux ACPI device is present
*
* Drivers may use this to activate quirks specific to dual GPU MacBook Pros
* and Mac Pros, e.g. for deferred probing, runtime pm and backlight.
*
- * Return: %true if gmux is present and the kernel was configured
+ * Return: %true if gmux ACPI device is present and the kernel was configured
* with CONFIG_APPLE_GMUX, %false otherwise.
*/
static inline bool apple_gmux_present(void)
@@ -34,6 +134,11 @@ static inline bool apple_gmux_present(void)
return false;
}
+static inline bool apple_gmux_detect(struct pnp_dev *pnp_dev, bool *indexed_ret)
+{
+ return false;
+}
+
#endif /* !CONFIG_APPLE_GMUX */
#endif /* LINUX_APPLE_GMUX_H */