diff options
Diffstat (limited to 'include/linux/apple-gmux.h')
-rw-r--r-- | include/linux/apple-gmux.h | 72 |
1 files changed, 54 insertions, 18 deletions
diff --git a/include/linux/apple-gmux.h b/include/linux/apple-gmux.h index 1f68b49bcd68..206d97ffda79 100644 --- a/include/linux/apple-gmux.h +++ b/include/linux/apple-gmux.h @@ -34,8 +34,20 @@ #define GMUX_PORT_READ 0xd0 #define GMUX_PORT_WRITE 0xd4 +#define GMUX_MMIO_PORT_SELECT 0x0e +#define GMUX_MMIO_COMMAND_SEND 0x0f + +#define GMUX_MMIO_READ 0x00 +#define GMUX_MMIO_WRITE 0x40 + #define GMUX_MIN_IO_LEN (GMUX_PORT_BRIGHTNESS + 4) +enum apple_gmux_type { + APPLE_GMUX_TYPE_PIO, + APPLE_GMUX_TYPE_INDEXED, + APPLE_GMUX_TYPE_MMIO, +}; + #if IS_ENABLED(CONFIG_APPLE_GMUX) static inline bool apple_gmux_is_indexed(unsigned long iostart) { @@ -52,11 +64,29 @@ static inline bool apple_gmux_is_indexed(unsigned long iostart) return false; } +static inline bool apple_gmux_is_mmio(unsigned long iostart) +{ + u8 __iomem *iomem_base = ioremap(iostart, 16); + u8 val; + + if (!iomem_base) + return false; + + /* + * If this is 0xff, then gmux must not be present, as the gmux would + * reset it to 0x00, or it would be one of 0x1, 0x4, 0x41, 0x44 if a + * command is currently being processed. + */ + val = ioread8(iomem_base + GMUX_MMIO_COMMAND_SEND); + iounmap(iomem_base); + return (val != 0xff); +} + /** * 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 + * @type_ret: Returns (by reference) the apple_gmux_type of the device * * Detect if a supported gmux device is present by actually probing it. * This avoids the false positives returned on some models by @@ -65,13 +95,13 @@ static inline bool apple_gmux_is_indexed(unsigned long iostart) * 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) +static inline bool apple_gmux_detect(struct pnp_dev *pnp_dev, enum apple_gmux_type *type_ret) { u8 ver_major, ver_minor, ver_release; struct device *dev = NULL; struct acpi_device *adev; struct resource *res; - bool indexed = false; + enum apple_gmux_type type = APPLE_GMUX_TYPE_PIO; bool ret = false; if (!pnp_dev) { @@ -88,24 +118,30 @@ static inline bool apple_gmux_detect(struct pnp_dev *pnp_dev, bool *indexed_ret) } 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) + if (res && resource_size(res) >= GMUX_MIN_IO_LEN) { + /* + * 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) { + if (apple_gmux_is_indexed(res->start)) + type = APPLE_GMUX_TYPE_INDEXED; + else + goto out; + } + } else { + res = pnp_get_resource(pnp_dev, IORESOURCE_MEM, 0); + if (res && apple_gmux_is_mmio(res->start)) + type = APPLE_GMUX_TYPE_MMIO; + else goto out; } - if (indexed_ret) - *indexed_ret = indexed; + if (type_ret) + *type_ret = type; ret = true; out: |