diff options
Diffstat (limited to 'include/linux/apple-gmux.h')
-rw-r--r-- | include/linux/apple-gmux.h | 56 |
1 files changed, 43 insertions, 13 deletions
diff --git a/include/linux/apple-gmux.h b/include/linux/apple-gmux.h index 147dc1c52e08..272f63f8fd7c 100644 --- a/include/linux/apple-gmux.h +++ b/include/linux/apple-gmux.h @@ -34,11 +34,18 @@ #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) @@ -57,6 +64,24 @@ 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 * @@ -93,19 +118,24 @@ static inline bool apple_gmux_detect(struct pnp_dev *pnp_dev, enum apple_gmux_ty } 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) { - if (apple_gmux_is_indexed(res->start)) - type = APPLE_GMUX_TYPE_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; } |