// SPDX-License-Identifier: GPL-2.0-only
/*
* Gmux driver for Apple laptops
*
* Copyright (C) Canonical Ltd. <seth.forshee@canonical.com>
* Copyright (C) 2010-2012 Andreas Heider <andreas@meetr.de>
* Copyright (C) 2015 Lukas Wunner <lukas@wunner.de>
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/backlight.h>
#include <linux/acpi.h>
#include <linux/pnp.h>
#include <linux/apple_bl.h>
#include <linux/apple-gmux.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/pci.h>
#include <linux/vga_switcheroo.h>
#include <acpi/video.h>
#include <asm/io.h>
/**
* DOC: Overview
*
* gmux is a microcontroller built into the MacBook Pro to support dual GPUs:
* A `Lattice XP2`_ on pre-retinas, a `Renesas R4F2113`_ on retinas.
*
* (The MacPro6,1 2013 also has a gmux, however it is unclear why since it has
* dual GPUs but no built-in display.)
*
* gmux is connected to the LPC bus of the southbridge. Its I/O ports are
* accessed differently depending on the microcontroller: Driver functions
* to access a pre-retina gmux are infixed ``_pio_``, those for a retina gmux
* are infixed ``_index_``.
*
* .. _Lattice XP2:
* http://www.latticesemi.com/en/Products/FPGAandCPLD/LatticeXP2.aspx
* .. _Renesas R4F2113:
* http://www.renesas.com/products/mpumcu/h8s/h8s2100/h8s2113/index.jsp
*/
struct apple_gmux_data {
unsigned long iostart;
unsigned long iolen;
bool indexed;
struct mutex index_lock;
struct backlight_device *bdev;
/* switcheroo data */
acpi_handle dhandle;
int gpe;
bool external_switchable;
enum vga_switcheroo_client_id switch_state_display;
enum vga_switcheroo_client_id switch_state_ddc;
enum vga_switcheroo_client_id switch_state_external;
enum vga_switcheroo_state power_state;
struct completion powerchange_done;
};
static struct apple_gmux_data *apple_gmux_data;
/*
* 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)
#define GMUX_INTERRUPT_ENABLE 0xff
#define GMUX_INTERRUPT_DISABLE 0x00
#define GMUX_INTERRUPT_STATUS_ACTIVE 0
#define GMUX_INTERRUPT_STATUS_DISPLAY (1 << 0)
#define GMUX_INTERRUPT_STATUS_POWER (1 << 2)
#define GMUX_INTERRUPT_STATUS_HOTPLUG (1 << 3)
#define GMUX_BRIGHTNESS_MASK 0x00ffffff
#define GMUX_MAX_BRIGHTNESS GMUX_BRIGHTNESS_MASK
static u8 gmux_pio_read8(struct apple_gmux_data *gmux_data, int port)
{
return inb(gmux_data->iostart + port);
}
static void gmux_pio_write8(struct apple_gmux_data *gmux_data, int port,
u8 val)
{
outb(val, gmux_data->iostart + port);
}
static u32 gmux_pio_read32(struct apple_gmux_data *gmux_data, int port)
{
return inl(gmux_data->iostart + port);
}
static void gmux_pio_write32(struct apple_gmux_data *gmux_data, int port,
u32 val)
{
int i;
u8 tmpval;
for (i = 0; i < 4; i++) {
tmpval = (val >> (i * 8)) & 0xff;
outb(tmpval, gmux_data->iostart + port + i);
}
}
static int gmux_index_wait_ready(struct apple_gmux_data *gmux_data)
{
int i = 200;
u8 gwr = inb(gmux_data->iostart + GMUX_PORT_WRITE);
while (i && (gwr & 0x01)) {
inb(gmux_data->iostart + GMUX_PORT_READ);
gwr = inb(gmux_data->iostart + GMUX_PORT_WRITE);
udelay(100);
i--;
}
return !!i;
}
static int gmux_index_wait_complete(struct apple_gmux_data *gmux_data)
{
int i = 200;
u8 gwr = inb(gmux_data->iostart + GMUX_PORT_WRITE);
while (i && !(gwr & 0x01)) {
gwr = inb(gmux_data->iostart + GMUX_PORT_WRITE);
udelay(100);
i--;
}
if (gwr & 0x01)
inb(gmux_data->iostart + GMUX_PORT_READ);
return !!i;
}
static u8 gmux_index_read8(struct apple_gmux_data *gmux_data, int port)
{
u8 val;
mutex_lock(&gmux_data->index_lock);
gmux_index_wait_ready(gmux_data);
outb((port & 0xff), gmux_data->iostart + GMUX_PORT_READ);
gmux_index_wait_complete(gmux_data);
val = inb(gmux_data->iostart + GMUX_PORT_VALUE);
mutex_unlock(&gmux_data->index_lock);
return val;
}
static void gmux_index_write8(struct apple_gmux_data *gmux_data, int port,
u8 val)
{
mutex_lock(&gmux_data->index_lock);
outb(val, gmux_data->iostart + GMUX_PORT_VALUE);
gmux_index_wait_ready(gmux_data);
outb(port & 0xff, gmux_data->iostart + GMUX_PORT_WRITE);
gmux_index_wait_complete(gmux_data);
mutex_unlock(&gmux_data->index_lock);
}
static u32 gmux_index_read32(struct apple_gmux_data *gmux_data, int port)
{
u32 val;
mutex_lock(&gmux_data->index_lock);
gmux_index_wait_ready(gmux_data);
outb((port & 0xff), gmux_data->iostart + GMUX_PORT_READ);
gmux_index_wait_complete(gmux_data);
val = inl(gmux_data->iostart + GMUX_PORT_VALUE);
mutex_unlock(&gmux_data->index_lock);
return val;
}
static void gmux_index_write32(struct apple_gmux_data *gmux_data, int port,
u32 val)
{
int i;
u8 tmpval;
mutex_lock(&gmux_data->index_lock);
for (i = 0; i < 4; i++) {
tmpval = (val >> (i * 8)) & 0xff;
outb(tmpval, gmux_data->iostart + GMUX_PORT_VALUE + i);
}
gmux_index_wait_ready(gmux_data);
outb(port & 0xff, gmux_data->iostart + GMUX_PORT_WRITE);
gmux_index_wait_complete(gmux_data);
mutex_unlock(&gmux_data->index_lock);
}
static u8 gmux_read8(struct apple_gmux_data *gmux_data, int port)
{
if (gmux_data->indexed)
return gmux_index_read8(gmux_data, port);
else
return gmux_pio_read8(gmux_data, port);
}
static void gmux_write8(struct apple_gmux_data *gmux_data, int port, u8 val)
{
if (gmux_data->indexed)
gmux_index_write8(gmux_data, port, val);
else
gmux_pio_write8(gmux_data, port, val);
}
static u32 gmux_read32(struct apple_gmux_data *gmux_data, int port)
{
if (gmux_data->indexed)
return gmux_index_read32(gmux_data, port);
else
return gmux_pio_read32(gmux_data, port);
}
static void gmux_write32(struct apple_gmux_data *gmux_data, int port,
u32 val)
{
if (gmux_data->indexed)
gmux_index_write32(gmux_data, port, val);
else
gmux_pio_write32(gmux_data, port, val);
}
static bool gmux_is_indexed(struct apple_gmux_data *gmux_data)
{
u16 val;
outb(0xaa, gmux_data->iostart + 0xcc);
outb(0x55, gmux_data->iostart + 0xcd);
outb(0x00, gmux_data->iostart + 0xce);
val = inb(gmux_data->iostart + 0xcc) |
(inb(gmux_data->iostart + 0xcd) << 8);
if (val == 0x55aa)
return true;
return false;
}
/**
* DOC: Backlight control
*
* On single GPU MacBooks, the PWM signal for the backlight is generated by
* the GPU. On dual GPU MacBook Pros by contrast, either GPU may be suspended
* to conserve energy. Hence the PWM signal needs to be generated by a separate
* backlight driver which is controlled by gmux. The earliest generation
* MBP5 2008/09 uses a `TI LP8543`_ backlight driver. All newer models
* use a `TI LP8545`_.
*
* .. _TI LP8543: https://www.ti.com/lit/ds/symlink/lp8543.pdf
* .. _TI LP8545: https://www.ti.com/lit/ds/symlink/lp8545.pdf
*/
static int gmux_get_brightness(struct backlight_device *bd)
{
struct apple_gmux_data *gmux_data = bl_get_data(bd);
return gmux_read32(gmux_data, GMUX_PORT_BRIGHTNESS) &
GMUX_BRIGHTNESS_MASK;
}
static int gmux_update_status(struct backlight_device *bd)
{
struct apple_gmux_data *gmux_data = bl_get_data(bd);
u32 brightness = bd->props.brightness;
if (bd->props.state & BL_CORE_SUSPENDED)
return 0;
gmux_write32(gmux_data, GMUX_PORT_BRIGHTNESS, brightness);
return 0;
}
static const struct backlight_ops gmux_bl_ops = {
.options = BL_CORE_SUSPENDRESUME,
.get_brightness = gmux_get_brightness,
.update_status = gmux_update_status,
};
/**
* DOC: Graphics mux
*
* On pre-retinas, the LVDS outputs of both GPUs feed into gmux which muxes
* either of them to the panel. One of the tricks gmux has up its sleeve is
* to lengthen the blanking interval of its output during a switch to
* synchronize it with the GPU switched to. This allows for a flicker-free
* switch that is imperceptible by the user (`US 8,687,007 B2`_).
*
* On retinas, muxing is no longer done by gmux itself, but by a separate
* chip which is controlled by gmux. The chip is triple sourced, it is
* either an `NXP CBTL06142`_, `TI HD3SS212`_ or `Pericom PI3VDP12412`_.
* The panel is driven with eDP instead of LVDS since the pixel clock
* required for retina resolution exceeds LVDS' limits.
*
* Pre-retinas are able to switch the panel's DDC pins separately.
* This is handled by a `TI SN74LV4066A`_ which is controlled by gmux.
* The inactive GPU can thus probe the panel's EDID without switching over
* the entire panel. Retinas lack this functionality as the chips used for
* eDP muxing are incapable of switching the AUX channel separately (see
* the linked data sheets, Pericom would be capable but this is unused).
* However the retina panel has the NO_AUX_HANDSHAKE_LINK_TRAINING bit set
* in its DPCD, allowing the inactive GPU to skip the AUX handshake and
* set up the output with link parameters pre-calibrated by the active GPU.
*
* The external DP port is only fully switchable on the first two unibody
* MacBook Pro generations, MBP5 2008/09 and MBP6 2010. This is done by an
* `NXP CBTL06141`_ which is controlled by gmux. It's the predecessor of the
* eDP mux on retinas, the difference being support for 2.7 versus 5.4 Gbit/s.
*
* The following MacBook Pro generations replaced the external DP port with a
* combined DP/Thunderbolt port and lost the ability to switch it between GPUs,
* connecting it either to the discrete GPU or the Thunderbolt controller.
* Oddly enough, while the full port is no longer switchable, AUX and HPD
* are still switchable by way of an `NXP CBTL03062`_ (on pre-retinas
* MBP8 2011 and MBP9 2012) or two `TI TS3DS10224`_ (on retinas) under the
* control of gmux. Since the integrated GPU is missing the main link,
* external displays appear to it as phantoms which fail to link-train.
*
* gmux receives the HPD signal of all display connectors and sends an
* interrupt on hotplug. On generations which cannot switch external ports,
* the discrete GPU can then be woken to drive the newly connected display.
* The ability to switch AUX on these generations could be used to improve
* reliability of hotplug detection by having the integrated GPU poll the
* ports while the discrete GPU is asleep, but currently we do not make use
* of this feature.
*
* Our switching policy for the external port is that on those generations
* which are able to switch it fully, the port is switched together with the
* panel when IGD / DIS commands are issued to vga_switcheroo. It is thus
* possible to drive e.g. a beamer on battery power with the integrated GPU.
* The user may manually switch to the discrete GPU if more performance is
* needed.
*
* On all newer generations, the external port can only be driven by the
* discrete GPU. If a display is plugged in while the panel is switched to
* the integrated GPU, *both* GPUs will be in use for maximum performance.
* To decrease power consumption, the user may manually switch to the
* discrete GPU, thereby suspending the integrated GPU.
*
* gmux' initial switch state on bootup is user configurable via the EFI
* variable ``gpu-power-prefs-fa4ce28d-b62f-4c99-9cc3-6815686e30f9`` (5th byte,
* 1 = IGD, 0 = DIS). Based on this setting, the EFI firmware tells gmux to
* switch the panel and the external DP connector and allocates a framebuffer
* for the selected GPU.
*
* .. _US 8,687,007 B2: https://pimg-fpiw.uspto.gov/fdd/07/870/086/0.pdf
* .. _NXP CBTL06141: https://www.nxp.com/documents/data_sheet/CBTL06141.pdf
* .. _NXP CBTL06142: https://www.nxp.com/documents/data_sheet/CBTL06141.pdf
* .. _TI HD3SS212: https://www.ti.com/lit/ds/symlink/hd3ss212.pdf
* .. _Pericom PI3VDP12412: https://www.pericom.com/assets/Datasheets/PI3VDP12412.pdf
* .. _TI SN74LV4066A: https://www.ti.com/lit/ds/symlink/sn74lv4066a.pdf
* .. _NXP CBTL03062: http://pdf.datasheetarchive.com/indexerfiles/Datasheets-SW16/DSASW00308511.pdf
* .. _TI TS3DS10224: https://www.ti.com/lit/ds/symlink/ts3ds10224.pdf
*/
static void gmux_read_switch_state(struct apple_gmux_data *gmux_data)
{
if (gmux_read8(gmux_data, GMUX_PORT_SWITCH_DDC) == 1)
gmux_data->switch_state_ddc = VGA_SWITCHEROO_IGD;
else
gmux_data->switch_state_ddc = VGA_SWITCHEROO_DIS;
if (gmux_read8(gmux_data, GMUX_PORT_SWITCH_DISPLAY) == 2)
gmux_data->switch_state_display = VGA_SWITCHEROO_IGD;
else
gmux_data->switch_state_display = VGA_SWITCHEROO_DIS;
if (gmux_read8(gmux_data, GMUX_PORT_SWITCH_EXTERNAL) == 2)
gmux_data->switch_state_external = VGA_SWITCHEROO_IGD;
else
gmux_data->switch_state_external = VGA_SWITCHEROO_DIS;
}
static void gmux_write_switch_state(struct apple_gmux_data *gmux_data)
{
if (gmux_data->switch_state_ddc == VGA_SWITCHEROO_IGD)
gmux_write8(gmux_data, GMUX_PORT_SWITCH_DDC, 1);
else
gmux_write8(gmux_data, GMUX_PORT_SWITCH_DDC, 2);
if (gmux_data->switch_state_display == VGA_SWITCHEROO_IGD)
gmux_write8(gmux_data, GMUX_PORT_SWITCH_DISPLAY, 2);
else
gmux_write8(gmux_data, GMUX_PORT_SWITCH_DISPLAY, 3);
if (gmux_data->switch_state_external == VGA_SWITCHEROO_IGD)
gmux_write8(gmux_data, GMUX_PORT_SWITCH_EXTERNAL, 2);
else
gmux_write8(gmux_data, GMUX_PORT_SWITCH_EXTERNAL, 3);
}
static int gmux_switchto(enum vga_switcheroo_client_id id)
{
apple_gmux_data->switch_state_ddc = id;
apple_gmux_data->switch_state_display = id;
if (apple_gmux_data->external_switchable)
apple_gmux_data->switch_state_external = id;
gmux_write_switch_state(apple_gmux_data);
return 0;
}
static int gmux_switch_ddc(enum vga_switcheroo_client_id id)
{
enum vga_switcheroo_client_id old_ddc_owner =
apple_gmux_data->switch_state_ddc;
if (id == old_ddc_owner)
return id;
pr_debug("Switching DDC from %d to %d\n", old_ddc_owner, id);
apple_gmux_data->switch_state_ddc = id;
if (id == VGA_SWITCHEROO_IGD)
gmux_write8(apple_gmux_data, GMUX_PORT_SWITCH_DDC, 1);
else
gmux_write8(apple_gmux_data, GMUX_PORT_SWITCH_DDC, 2);
return old_ddc_owner;
}
/**
* DOC: Power control
*
* gmux is able to cut power to the discrete GPU. It automatically takes care
* of the correct sequence to tear down and bring up the power rails for
* core voltage, VRAM and PCIe.
*/
static int gmux_set_discrete_state(struct apple_gmux_data *gmux_data,
enum vga_switcheroo_state state)
{
reinit_completion(&gmux_data->powerchange_done);
if (state == VGA_SWITCHEROO_ON) {
gmux_write8(gmux_data, GMUX_PORT_DISCRETE_POWER, 1);
gmux_write8(gmux_data, GMUX_PORT_DISCRETE_POWER, 3);
pr_debug("Discrete card powered up\n");
} else {
gmux_write8(gmux_data, GMUX_PORT_DISCRETE_POWER, 1);
gmux_write8(gmux_data, GMUX_PORT_DISCRETE_POWER, 0);
pr_debug("Discrete card powered down\n");
}
gmux_data->power_state = state;
if (gmux_data->gpe >= 0 &&
!wait_for_completion_interruptible_timeout(&gmux_data->powerchange_done,
msecs_to_jiffies(200)))
pr_warn("Timeout waiting for gmux switch to complete\n");
return 0;
}
static int gmux_set_power_state(enum vga_switcheroo_client_id id,
enum vga_switcheroo_state state)
{
if (id == VGA_SWITCHEROO_IGD)
return 0;
return gmux_set_discrete_state(apple_gmux_data, state);
}
static enum vga_switcheroo_client_id gmux_get_client_id(struct pci_dev *pdev)
{
/*
* Early Macbook Pros with switchable graphics use nvidia
* integrated graphics. Hardcode that the 9400M is integrated.
*/
if (pdev->vendor == PCI_VENDOR_ID_INTEL)
return VGA_SWITCHEROO_IGD;
else if (pdev->vendor == PCI_VENDOR_ID_NVIDIA &&
pdev->device == 0x0863)
return VGA_SWITCHEROO_IGD;
else
return VGA_SWITCHEROO_DIS;
}
static const struct vga_switcheroo_handler gmux_handler_indexed = {
.switchto = gmux_switchto,
.power_state = gmux_set_power_state,
.get_client_id = gmux_get_client_id,
};
static const struct vga_switcheroo_handler gmux_handler_classic = {
.switchto = gmux_switchto,
.switch_ddc = gmux_switch_ddc,
.power_state = gmux_set_power_state,
.get_client_id = gmux_get_client_id,
};
/**
* DOC: Interrupt
*
* gmux is also connected to a GPIO pin of the southbridge and thereby is able
* to trigger an ACPI GPE. On the MBP5 2008/09 it's GPIO pin 22 of the Nvidia
* MCP79, on all following generations it's GPIO pin 6 of the Intel PCH.
* The GPE merely signals that an interrupt occurred, the actual type of event
* is identified by reading a gmux register.
*/
static inline void gmux_disable_interrupts(struct apple_gmux_data *gmux_data)
{
gmux_write8(gmux_data, GMUX_PORT_INTERRUPT_ENABLE,
GMUX_INTERRUPT_DISABLE);
}
static inline void gmux_enable_interrupts(struct apple_gmux_data *gmux_data)
{
gmux_write8(gmux_data, GMUX_PORT_INTERRUPT_ENABLE,
GMUX_INTERRUPT_ENABLE);
}
static inline u8 gmux_interrupt_get_status(struct apple_gmux_data *gmux_data)
{
return gmux_read8(gmux_data, GMUX_PORT_INTERRUPT_STATUS);
}
static void gmux_clear_interrupts(struct apple_gmux_data *gmux_data)
{
u8 status;
/* to clear interrupts write back current status */
status = gmux_interrupt_get_status(gmux_data);
gmux_write8(gmux_data, GMUX_PORT_INTERRUPT_STATUS, status);
}
static void gmux_notify_handler(acpi_handle device, u32 value, void *context)
{
u8 status;
struct pnp_dev *pnp = (struct pnp_dev *)context;
struct apple_gmux_data *gmux_data = pnp_get_drvdata(pnp);
status = gmux_interrupt_get_status(gmux_data);
gmux_disable_interrupts(gmux_data);
pr_debug("Notify handler called: status %d\n", status);
gmux_clear_interrupts(gmux_data);
gmux_enable_interrupts(gmux_data);
if (status & GMUX_INTERRUPT_STATUS_POWER)
complete(&gmux_data->powerchange_done);
}
static int gmux_suspend(struct device *dev)
{
struct pnp_dev *pnp = to_pnp_dev(dev);
struct apple_gmux_data *gmux_data = pnp_get_drvdata(pnp);
gmux_disable_interrupts(gmux_data);
return 0;
}
static int gmux_resume(struct device *dev)
{
struct pnp_dev *pnp = to_pnp_dev(dev);
struct apple_gmux_data *gmux_data = pnp_get_drvdata(pnp);
gmux_enable_interrupts(gmux_data);
gmux_write_switch_state(gmux_data);
if (gmux_data->power_state == VGA_SWITCHEROO_OFF)
gmux_set_discrete_state(gmux_data, gmux_data->power_state);
return 0;
}
static int is_thunderbolt(struct device *dev, void *data)
{
return to_pci_dev(dev)->is_thunderbolt;
}
static int gmux_probe(struct pnp_dev *pnp, const struct pnp_device_id *id)
{
struct apple_gmux_data *gmux_data;
struct resource *res;
struct backlight_properties props;
struct backlight_device *bdev;
u8 ver_major, ver_minor, ver_release;
int ret = -ENXIO;
acpi_status status;
unsigned long long gpe;
if (apple_gmux_data)
return -EBUSY;
gmux_data = kzalloc(sizeof(*gmux_data), GFP_KERNEL);
if (!gmux_data)
return -ENOMEM;
pnp_set_drvdata(pnp, gmux_data);
res = pnp_get_resource(pnp, IORESOURCE_IO, 0);
if (!res) {
pr_err("Failed to find gmux I/O resource\n");
goto err_free;
}
gmux_data->iostart = res->start;
gmux_data->iolen = res->end - res->start;
if (gmux_data->iolen < GMUX_MIN_IO_LEN) {
pr_err("gmux I/O region too small (%lu < %u)\n",
gmux_data->iolen, GMUX_MIN_IO_LEN);
goto err_free;
}
if (!request_region(gmux_data->iostart, gmux_data->iolen,
"Apple gmux")) {
pr_err("gmux I/O already in use\n");
goto err_free;
}
/*
* 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 = gmux_read8(gmux_data, GMUX_PORT_VERSION_MAJOR);
ver_minor = gmux_read8(gmux_data, GMUX_PORT_VERSION_MINOR);
ver_release = gmux_read8(gmux_data, GMUX_PORT_VERSION_RELEASE);
if (ver_major == 0xff && ver_minor == 0xff && ver_release == 0xff) {
if (gmux_is_indexed(gmux_data)) {
u32 version;
mutex_init(&gmux_data->index_lock);
gmux_data->indexed = true;
version = gmux_read32(gmux_data,
GMUX_PORT_VERSION_MAJOR);
ver_major = (version >> 24) & 0xff;
ver_minor = (version >> 16) & 0xff;
ver_release = (version >> 8) & 0xff;
} else {
pr_info("gmux device not present\n");
ret = -ENODEV;
goto err_release;
}
}
pr_info("Found gmux version %d.%d.%d [%s]\n", ver_major, ver_minor,
ver_release, (gmux_data->indexed ? "indexed" : "classic"));
memset(&props, 0, sizeof(props));
props.type = BACKLIGHT_PLATFORM;
props.max_brightness = gmux_read32(gmux_data, GMUX_PORT_MAX_BRIGHTNESS);
/*
* Currently it's assumed that the maximum brightness is less than
* 2^24 for compatibility with old gmux versions. Cap the max
* brightness at this value, but print a warning if the hardware
* reports something higher so that it can be fixed.
*/
if (WARN_ON(props.max_brightness > GMUX_MAX_BRIGHTNESS))
props.max_brightness = GMUX_MAX_BRIGHTNESS;
bdev = backlight_device_register("gmux_backlight", &pnp->dev,
gmux_data, &gmux_bl_ops, &props);
if (IS_ERR(bdev)) {
ret = PTR_ERR(bdev);
goto err_release;
}
gmux_data->bdev = bdev;
bdev->props.brightness = gmux_get_brightness(bdev);
backlight_update_status(bdev);
/*
* The backlight situation on Macs is complicated. If the gmux is
* present it's the best choice, because it always works for
* backlight control and supports more levels than other options.
* Disable the other backlight choices.
*/
acpi_video_set_dmi_backlight_type(acpi_backlight_vendor);
apple_bl_unregister();
gmux_data->power_state = VGA_SWITCHEROO_ON;
gmux_data->dhandle = ACPI_HANDLE(&pnp->dev);
if (!gmux_data->dhandle) {
pr_err("Cannot find acpi handle for pnp device %s\n",
dev_name(&pnp->dev));
ret = -ENODEV;
goto err_notify;
}
status = acpi_evaluate_integer(gmux_data->dhandle, "GMGP", NULL, &gpe);
if (ACPI_SUCCESS(status)) {
gmux_data->gpe = (int)gpe;
status = acpi_install_notify_handler(gmux_data->dhandle,
ACPI_DEVICE_NOTIFY,
&gmux_notify_handler, pnp);
if (ACPI_FAILURE(status)) {
pr_err("Install notify handler failed: %s\n",
acpi_format_exception(status));
ret = -ENODEV;
goto err_notify;
}
status = acpi_enable_gpe(NULL, gmux_data->gpe);
if (ACPI_FAILURE(status)) {
pr_err("Cannot enable gpe: %s\n",
acpi_format_exception(status));
goto err_enable_gpe;
}
} else {
pr_warn("No GPE found for gmux\n");
gmux_data->gpe = -1;
}
/*
* If Thunderbolt is present, the external DP port is not fully
* switchable. Force its AUX channel to the discrete GPU.
*/
gmux_data->external_switchable =
!bus_for_each_dev(&pci_bus_type, NULL, NULL, is_thunderbolt);
if (!gmux_data->external_switchable)
gmux_write8(gmux_data, GMUX_PORT_SWITCH_EXTERNAL, 3);
apple_gmux_data = gmux_data;
init_completion(&gmux_data->powerchange_done);
gmux_enable_interrupts(gmux_data);
gmux_read_switch_state(gmux_data);
/*
* Retina MacBook Pros cannot switch the panel's AUX separately
* and need eDP pre-calibration. They are distinguishable from
* pre-retinas by having an "indexed" gmux.
*
* Pre-retina MacBook Pros can switch the panel's DDC separately.
*/
if (gmux_data->indexed)
ret = vga_switcheroo_register_handler(&gmux_handler_indexed,
VGA_SWITCHEROO_NEEDS_EDP_CONFIG);
else
ret = vga_switcheroo_register_handler(&gmux_handler_classic,
VGA_SWITCHEROO_CAN_SWITCH_DDC);
if (ret) {
pr_err("Failed to register vga_switcheroo handler\n");
goto err_register_handler;
}
return 0;
err_register_handler:
gmux_disable_interrupts(gmux_data);
apple_gmux_data = NULL;
if (gmux_data->gpe >= 0)
acpi_disable_gpe(NULL, gmux_data->gpe);
err_enable_gpe:
if (gmux_data->gpe >= 0)
acpi_remove_notify_handler(gmux_data->dhandle,
ACPI_DEVICE_NOTIFY,
&gmux_notify_handler);
err_notify:
backlight_device_unregister(bdev);
err_release:
release_region(gmux_data->iostart, gmux_data->iolen);
err_free:
kfree(gmux_data);
return ret;
}
static void gmux_remove(struct pnp_dev *pnp)
{
struct apple_gmux_data *gmux_data = pnp_get_drvdata(pnp);
vga_switcheroo_unregister_handler();
gmux_disable_interrupts(gmux_data);
if (gmux_data->gpe >= 0) {
acpi_disable_gpe(NULL, gmux_data->gpe);
acpi_remove_notify_handler(gmux_data->dhandle,
ACPI_DEVICE_NOTIFY,
&gmux_notify_handler);
}
backlight_device_unregister(gmux_data->bdev);
release_region(gmux_data->iostart, gmux_data->iolen);
apple_gmux_data = NULL;
kfree(gmux_data);
acpi_video_register();
apple_bl_register();
}
static const struct pnp_device_id gmux_device_ids[] = {
{GMUX_ACPI_HID, 0},
{"", 0}
};
static const struct dev_pm_ops gmux_dev_pm_ops = {
.suspend = gmux_suspend,
.resume = gmux_resume,
};
static struct pnp_driver gmux_pnp_driver = {
.name = "apple-gmux",
.probe = gmux_probe,
.remove = gmux_remove,
.id_table = gmux_device_ids,
.driver = {
.pm = &gmux_dev_pm_ops,
},
};
module_pnp_driver(gmux_pnp_driver);
MODULE_AUTHOR("Seth Forshee <seth.forshee@canonical.com>");
MODULE_DESCRIPTION("Apple Gmux Driver");
MODULE_LICENSE("GPL");
MODULE_DEVICE_TABLE(pnp, gmux_device_ids);