/* SPDX-License-Identifier: GPL-2.0-only */
/*
* apple-gmux.h - microcontroller built into dual GPU MacBook Pro & Mac Pro
* Copyright (C) 2015 Lukas Wunner <[email protected]>
*/
#ifndef LINUX_APPLE_GMUX_H
#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_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)
{
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;
}
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
* @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
* 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, enum apple_gmux_type *type_ret)
{
u8 ver_major, ver_minor, ver_release;
struct device *dev = NULL;
struct acpi_device *adev;
struct resource *res;
enum apple_gmux_type type = APPLE_GMUX_TYPE_PIO;
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) {
/*
* 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 (type_ret)
*type_ret = type;
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 ACPI device is present and the kernel was configured
* with CONFIG_APPLE_GMUX, %false otherwise.
*/
static inline bool apple_gmux_present(void)
{
return acpi_dev_found(GMUX_ACPI_HID);
}
#else /* !CONFIG_APPLE_GMUX */
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 */
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