[linux-block.git] / include / linux / apple-gmux.h

/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * apple-gmux.h - microcontroller built into dual GPU MacBook Pro & Mac Pro
 * Copyright (C) 2015 Lukas Wunner <lukas@wunner.de>
 */

#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 */
Commit	Line	Data
caab277b	1	/* SPDX-License-Identifier: GPL-2.0-only */
2413306c LW	2	/*
	3	* apple-gmux.h - microcontroller built into dual GPU MacBook Pro & Mac Pro
	4	* Copyright (C) 2015 Lukas Wunner <lukas@wunner.de>
2413306c LW	5	*/
	6
	7	#ifndef LINUX_APPLE_GMUX_H
	8	#define LINUX_APPLE_GMUX_H
	9
	10	#include <linux/acpi.h>
d143908f HG	11	#include <linux/io.h>
d143908f HG	12	#include <linux/pnp.h>
2413306c LW	13
	14	#define GMUX_ACPI_HID "APP000B"
	15
39f5a81f HG	16	/*
	17	* gmux port offsets. Many of these are not yet used, but may be in the
	18	* future, and it's useful to have them documented here anyhow.
	19	*/
	20	#define GMUX_PORT_VERSION_MAJOR 0x04
	21	#define GMUX_PORT_VERSION_MINOR 0x05
	22	#define GMUX_PORT_VERSION_RELEASE 0x06
	23	#define GMUX_PORT_SWITCH_DISPLAY 0x10
	24	#define GMUX_PORT_SWITCH_GET_DISPLAY 0x11
	25	#define GMUX_PORT_INTERRUPT_ENABLE 0x14
	26	#define GMUX_PORT_INTERRUPT_STATUS 0x16
	27	#define GMUX_PORT_SWITCH_DDC 0x28
	28	#define GMUX_PORT_SWITCH_EXTERNAL 0x40
	29	#define GMUX_PORT_SWITCH_GET_EXTERNAL 0x41
	30	#define GMUX_PORT_DISCRETE_POWER 0x50
	31	#define GMUX_PORT_MAX_BRIGHTNESS 0x70
	32	#define GMUX_PORT_BRIGHTNESS 0x74
	33	#define GMUX_PORT_VALUE 0xc2
	34	#define GMUX_PORT_READ 0xd0
	35	#define GMUX_PORT_WRITE 0xd4
	36
0c18184d OC	37	#define GMUX_MMIO_PORT_SELECT 0x0e
	38	#define GMUX_MMIO_COMMAND_SEND 0x0f
	39
	40	#define GMUX_MMIO_READ 0x00
	41	#define GMUX_MMIO_WRITE 0x40
	42
39f5a81f HG	43	#define GMUX_MIN_IO_LEN (GMUX_PORT_BRIGHTNESS + 4)
39f5a81f HG	44
96ec2d98 OC	45	enum apple_gmux_type {
	46	APPLE_GMUX_TYPE_PIO,
	47	APPLE_GMUX_TYPE_INDEXED,
0c18184d	48	APPLE_GMUX_TYPE_MMIO,
96ec2d98 OC	49	};
96ec2d98 OC	50
b7172119	51	#if IS_ENABLED(CONFIG_APPLE_GMUX)
d143908f HG	52	static inline bool apple_gmux_is_indexed(unsigned long iostart)
	53	{
	54	u16 val;
	55
	56	outb(0xaa, iostart + 0xcc);
	57	outb(0x55, iostart + 0xcd);
	58	outb(0x00, iostart + 0xce);
	59
	60	val = inb(iostart + 0xcc) \| (inb(iostart + 0xcd) << 8);
	61	if (val == 0x55aa)
	62	return true;
	63
	64	return false;
	65	}
b7172119	66
0c18184d OC	67	static inline bool apple_gmux_is_mmio(unsigned long iostart)
0c18184d OC	68	{
fb131c47	69	u8 __iomem *iomem_base = ioremap(iostart, 16);
0c18184d OC	70	u8 val;
	71
	72	if (!iomem_base)
	73	return false;
	74
	75	/*
	76	* If this is 0xff, then gmux must not be present, as the gmux would
	77	* reset it to 0x00, or it would be one of 0x1, 0x4, 0x41, 0x44 if a
	78	* command is currently being processed.
	79	*/
	80	val = ioread8(iomem_base + GMUX_MMIO_COMMAND_SEND);
	81	iounmap(iomem_base);
	82	return (val != 0xff);
	83	}
	84
2413306c	85	/**
d143908f HG	86	* apple_gmux_detect() - detect if gmux is built into the machine
	87	*
	88	* @pnp_dev: Device to probe or NULL to use the first matching device
ad3d0ee8	89	* @type_ret: Returns (by reference) the apple_gmux_type of the device
d143908f HG	90	*
	91	* Detect if a supported gmux device is present by actually probing it.
	92	* This avoids the false positives returned on some models by
	93	* apple_gmux_present().
	94	*
	95	* Return: %true if a supported gmux ACPI device is detected and the kernel
	96	* was configured with CONFIG_APPLE_GMUX, %false otherwise.
	97	*/
96ec2d98	98	static inline bool apple_gmux_detect(struct pnp_dev pnp_dev, enum apple_gmux_type type_ret)
d143908f HG	99	{
	100	u8 ver_major, ver_minor, ver_release;
	101	struct device *dev = NULL;
	102	struct acpi_device *adev;
	103	struct resource *res;
96ec2d98	104	enum apple_gmux_type type = APPLE_GMUX_TYPE_PIO;
d143908f HG	105	bool ret = false;
	106
	107	if (!pnp_dev) {
	108	adev = acpi_dev_get_first_match_dev(GMUX_ACPI_HID, NULL, -1);
	109	if (!adev)
	110	return false;
	111
	112	dev = get_device(acpi_get_first_physical_node(adev));
	113	acpi_dev_put(adev);
	114	if (!dev)
	115	return false;
	116
	117	pnp_dev = to_pnp_dev(dev);
	118	}
	119
	120	res = pnp_get_resource(pnp_dev, IORESOURCE_IO, 0);
0c18184d OC	121	if (res && resource_size(res) >= GMUX_MIN_IO_LEN) {
	122	/*
	123	* Invalid version information may indicate either that the gmux
	124	* device isn't present or that it's a new one that uses indexed io.
	125	*/
	126	ver_major = inb(res->start + GMUX_PORT_VERSION_MAJOR);
	127	ver_minor = inb(res->start + GMUX_PORT_VERSION_MINOR);
	128	ver_release = inb(res->start + GMUX_PORT_VERSION_RELEASE);
	129	if (ver_major == 0xff && ver_minor == 0xff && ver_release == 0xff) {
	130	if (apple_gmux_is_indexed(res->start))
	131	type = APPLE_GMUX_TYPE_INDEXED;
	132	else
	133	goto out;
	134	}
	135	} else {
	136	res = pnp_get_resource(pnp_dev, IORESOURCE_MEM, 0);
	137	if (res && apple_gmux_is_mmio(res->start))
	138	type = APPLE_GMUX_TYPE_MMIO;
96ec2d98	139	else
d143908f HG	140	goto out;
	141	}
	142
96ec2d98 OC	143	if (type_ret)
96ec2d98 OC	144	*type_ret = type;
d143908f HG	145
	146	ret = true;
	147	out:
	148	put_device(dev);
	149	return ret;
	150	}
	151
	152	/**
	153	* apple_gmux_present() - check if gmux ACPI device is present
2413306c LW	154	*
	155	* Drivers may use this to activate quirks specific to dual GPU MacBook Pros
	156	* and Mac Pros, e.g. for deferred probing, runtime pm and backlight.
	157	*
d143908f	158	* Return: %true if gmux ACPI device is present and the kernel was configured
2413306c LW	159	* with CONFIG_APPLE_GMUX, %false otherwise.
	160	*/
	161	static inline bool apple_gmux_present(void)
	162	{
c68ae33e	163	return acpi_dev_found(GMUX_ACPI_HID);
2413306c LW	164	}
2413306c LW	165
b7172119 LW	166	#else /* !CONFIG_APPLE_GMUX */
	167
	168	static inline bool apple_gmux_present(void)
	169	{
	170	return false;
	171	}
	172
d143908f HG	173	static inline bool apple_gmux_detect(struct pnp_dev pnp_dev, bool indexed_ret)
	174	{
	175	return false;
	176	}
	177
b7172119 LW	178	#endif /* !CONFIG_APPLE_GMUX */
b7172119 LW	179
2413306c	180	#endif /* LINUX_APPLE_GMUX_H */