diff options
Diffstat (limited to 'include/linux/apple-gmux.h')
| -rw-r--r-- | include/linux/apple-gmux.h | 109 |
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 */ |