// SPDX-License-Identifier: GPL-2.0-only
/*
* Gmux driver for Apple laptops
*
* Copyright (C) Canonical Ltd. <[email protected]>
* Copyright (C) 2010-2012 Andreas Heider <[email protected]>
* Copyright (C) 2015 Lukas Wunner <[email protected]>
* Copyright (C) 2023 Orlando Chamberlain <[email protected]>
*/
#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-gmux.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/pci.h>
#include <linux/vga_switcheroo.h>
#include <linux/debugfs.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 pre-T2 retinas.
*
* On T2 Macbooks, the gmux is part of the T2 Coprocessor's SMC. The SMC has
* an I2C connection to a `NXP PCAL6524` GPIO expander, which enables/disables
* the voltage regulators of the discrete GPU, drives the display panel power,
* and has a GPIO to switch the eDP mux. The Intel CPU can interact with
* gmux through MMIO, similar to how the main SMC interface is controlled.
*
* (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 pre-T2
* retina gmux are infixed ``_index_``, and those on T2 Macs are infixed
* with ``_mmio_``.
*
* .. _Lattice XP2:
* http://www.latticesemi.com/en/Products/FPGAandCPLD/LatticeXP2.aspx
* .. _Renesas R4F2113:
* http://www.renesas.com/products/mpumcu/h8s/h8s2100/h8s2113/index.jsp
* .. _NXP PCAL6524:
* https://www.nxp.com/docs/en/data-sheet/PCAL6524.pdf
*/
struct apple_gmux_config;
struct apple_gmux_data {
u8 __iomem *iomem_base;
unsigned long iostart;
unsigned long iolen;
const struct apple_gmux_config *config;
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;
/* debugfs data */
u8 selected_port;
struct dentry *debug_dentry;
};
static struct apple_gmux_data *apple_gmux_data;
struct apple_gmux_config {
u8 (*read8)(struct apple_gmux_data *gmux_data, int port);
void (*write8)(struct apple_gmux_data *gmux_data, int port, u8 val);
u32 (*read32)(struct apple_gmux_data *gmux_data, int port);
void (*write32)(struct apple_gmux_data *gmux_data, int port, u32 val);
const struct vga_switcheroo_handler *gmux_handler;
enum vga_switcheroo_handler_flags_t handler_flags;
unsigned long resource_type;
bool read_version_as_u32;
char *name;
};
#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
# define MMIO_GMUX_MAX_BRIGHTNESS 0xffff
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 int gmux_mmio_wait(struct apple_gmux_data *gmux_data)
{
int i = 200;
u8 gwr = ioread8(gmux_data->iomem_base + GMUX_MMIO_COMMAND_SEND);
while (i && gwr) {
gwr = ioread8(gmux_data->iomem_base + GMUX_MMIO_COMMAND_SEND);
udelay(100);
i--;
}
return !!i;
}
static u8 gmux_mmio_read8(struct apple_gmux_data *gmux_data, int port)
{
u8 val;
mutex_lock(&gmux_data->index_lock);
gmux_mmio_wait(gmux_data);
iowrite8((port & 0xff), gmux_data->iomem_base + GMUX_MMIO_PORT_SELECT);
iowrite8(GMUX_MMIO_READ | sizeof(val),
gmux_data->iomem_base + GMUX_MMIO_COMMAND_SEND);
gmux_mmio_wait(gmux_data);
val = ioread8(gmux_data->iomem_base);
mutex_unlock(&gmux_data->index_lock);
return val;
}
static void gmux_mmio_write8(struct apple_gmux_data *gmux_data, int port,
u8 val)
{
mutex_lock(&gmux_data->index_lock);
gmux_mmio_wait(gmux_data);
iowrite8(val, gmux_data->iomem_base);
iowrite8(port & 0xff, gmux_data->iomem_base + GMUX_MMIO_PORT_SELECT);
iowrite8(GMUX_MMIO_WRITE | sizeof(val),
gmux_data->iomem_base + GMUX_MMIO_COMMAND_SEND);
gmux_mmio_wait(gmux_data);
mutex_unlock(&gmux_data->index_lock);
}
static u32 gmux_mmio_read32(struct apple_gmux_data *gmux_data, int port)
{
u32 val;
mutex_lock(&gmux_data->index_lock);
gmux_mmio_wait(gmux_data);
iowrite8((port & 0xff), gmux_data->iomem_base + GMUX_MMIO_PORT_SELECT);
iowrite8(GMUX_MMIO_READ | sizeof(val),
gmux_data->iomem_base + GMUX_MMIO_COMMAND_SEND);
gmux_mmio_wait(gmux_data);
val = ioread32be(gmux_data->iomem_base);
mutex_unlock(&gmux_data->index_lock);
return val;
}
static void gmux_mmio_write32(struct apple_gmux_data *gmux_data, int port,
u32 val)
{
mutex_lock(&gmux_data->index_lock);
iowrite32be(val, gmux_data->iomem_base);
iowrite8(port & 0xff, gmux_data->iomem_base + GMUX_MMIO_PORT_SELECT);
iowrite8(GMUX_MMIO_WRITE | sizeof(val),
gmux_data->iomem_base + GMUX_MMIO_COMMAND_SEND);
gmux_mmio_wait(gmux_data);
mutex_unlock(&gmux_data->index_lock);
}
static u8 gmux_read8(struct apple_gmux_data *gmux_data, int port)
{
return gmux_data->config->read8(gmux_data, port);
}
static void gmux_write8(struct apple_gmux_data *gmux_data, int port, u8 val)
{
return gmux_data->config->write8(gmux_data, port, val);
}
static u32 gmux_read32(struct apple_gmux_data *gmux_data, int port)
{
return gmux_data->config->read32(gmux_data, port);
}
static void gmux_write32(struct apple_gmux_data *gmux_data, int port,
u32 val)
{
return gmux_data->config->write32(gmux_data, port, val);
}
/**
* 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. Newer models
* use a `TI LP8545`_ or a TI LP8548.
*
* .. _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 = backlight_get_brightness(bd);
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 pre-t2 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) & 1)
gmux_data->switch_state_display = VGA_SWITCHEROO_DIS;
else
gmux_data->switch_state_display = VGA_SWITCHEROO_IGD;
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_no_ddc = {
.switchto = gmux_switchto,
.power_state = gmux_set_power_state,
.get_client_id = gmux_get_client_id,
};
static const struct vga_switcheroo_handler gmux_handler_ddc = {
.switchto = gmux_switchto,
.switch_ddc = gmux_switch_ddc,
.power_state = gmux_set_power_state,
.get_client_id = gmux_get_client_id,
};
static const struct apple_gmux_config apple_gmux_pio = {
.read8 = &gmux_pio_read8,
.write8 = &gmux_pio_write8,
.read32 = &gmux_pio_read32,
.write32 = &gmux_pio_write32,
.gmux_handler = &gmux_handler_ddc,
.handler_flags = VGA_SWITCHEROO_CAN_SWITCH_DDC,
.resource_type = IORESOURCE_IO,
.read_version_as_u32 = false,
.name = "classic"
};
static const struct apple_gmux_config apple_gmux_index = {
.read8 = &gmux_index_read8,
.write8 = &gmux_index_write8,
.read32 = &gmux_index_read32,
.write32 = &gmux_index_write32,
.gmux_handler = &gmux_handler_no_ddc,
.handler_flags = VGA_SWITCHEROO_NEEDS_EDP_CONFIG,
.resource_type = IORESOURCE_IO,
.read_version_as_u32 = true,
.name = "indexed"
};
static const struct apple_gmux_config apple_gmux_mmio = {
.read8 = &gmux_mmio_read8,
.write8 = &gmux_mmio_write8,
.read32 = &gmux_mmio_read32,
.write32 = &gmux_mmio_write32,
.gmux_handler = &gmux_handler_no_ddc,
.handler_flags = VGA_SWITCHEROO_NEEDS_EDP_CONFIG,
.resource_type = IORESOURCE_MEM,
.read_version_as_u32 = true,
.name = "T2"
};
/**
* DOC: Interrupt
*
* gmux is also connected to a GPIO pin of the southbridge and thereby is able
* to trigger an ACPI GPE. ACPI name GMGP holds this GPIO pin's number. On the
* MBP5 2008/09 it's GPIO pin 22 of the Nvidia MCP79, on following generations
* it's GPIO pin 6 of the Intel PCH, on MMIO gmux's it's pin 21.
*
* The GPE merely signals that an interrupt occurred, the actual type of event
* is identified by reading a gmux register.
*
* In addition to the GMGP name, gmux's ACPI device also has two methods GMSP
* and GMLV. GMLV likely means "GMUX Level", and reads the value of the GPIO,
* while GMSP likely means "GMUX Set Polarity", and seems to write to the GPIO's
* value. On newer Macbooks (This was introduced with or sometime before the
* MacBookPro14,3), the ACPI GPE method differentiates between the OS type: On
* Darwin, only a notification is signaled, whereas on other OSes, the GPIO's
* value is read and then inverted.
*
* Because Linux masquerades as Darwin, it ends up in the notification-only code
* path. On MMIO gmux's, this seems to lead to us being unable to clear interrupts,
* unless we call GMSP(0). Without this, there is a flood of status=0 interrupts
* that can't be cleared. This issue seems to be unique to MMIO gmux's.
*/
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);
/* Prevent flood of status=0 interrupts */
if (gmux_data->config == &apple_gmux_mmio)
acpi_execute_simple_method(gmux_data->dhandle, "GMSP", 0);
}
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);
}
/**
* DOC: Debugfs Interface
*
* gmux ports can be accessed from userspace as a debugfs interface. For example:
*
* # echo 4 > /sys/kernel/debug/apple_gmux/selected_port
* # cat /sys/kernel/debug/apple_gmux/selected_port_data | xxd -p
* 00000005
*
* Reads 4 bytes from port 4 (GMUX_PORT_VERSION_MAJOR).
*
* 1 and 4 byte writes are also allowed.
*/
static ssize_t gmux_selected_port_data_write(struct file *file,
const char __user *userbuf, size_t count, loff_t *ppos)
{
struct apple_gmux_data *gmux_data = file->private_data;
if (*ppos)
return -EINVAL;
if (count == 1) {
u8 data;
if (copy_from_user(&data, userbuf, 1))
return -EFAULT;
gmux_write8(gmux_data, gmux_data->selected_port, data);
} else if (count == 4) {
u32 data;
if (copy_from_user(&data, userbuf, 4))
return -EFAULT;
gmux_write32(gmux_data, gmux_data->selected_port, data);
} else
return -EINVAL;
return count;
}
static ssize_t gmux_selected_port_data_read(struct file *file,
char __user *userbuf, size_t count, loff_t *ppos)
{
struct apple_gmux_data *gmux_data = file->private_data;
u32 data;
data = gmux_read32(gmux_data, gmux_data->selected_port);
return simple_read_from_buffer(userbuf, count, ppos, &data, sizeof(data));
}
static const struct file_operations gmux_port_data_ops = {
.open = simple_open,
.write = gmux_selected_port_data_write,
.read = gmux_selected_port_data_read
};
static void gmux_init_debugfs(struct apple_gmux_data *gmux_data)
{
gmux_data->debug_dentry = debugfs_create_dir(KBUILD_MODNAME, NULL);
debugfs_create_u8("selected_port", 0644, gmux_data->debug_dentry,
&gmux_data->selected_port);
debugfs_create_file("selected_port_data", 0644, gmux_data->debug_dentry,
gmux_data, &gmux_port_data_ops);
}
static void gmux_fini_debugfs(struct apple_gmux_data *gmux_data)
{
debugfs_remove_recursive(gmux_data->debug_dentry);
}
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 = NULL;
u8 ver_major, ver_minor, ver_release;
bool register_bdev = true;
int ret = -ENXIO;
acpi_status status;
unsigned long long gpe;
enum apple_gmux_type type;
u32 version;
if (apple_gmux_data)
return -EBUSY;
if (!apple_gmux_detect(pnp, &type)) {
pr_info("gmux device not present\n");
return -ENODEV;
}
gmux_data = kzalloc(sizeof(*gmux_data), GFP_KERNEL);
if (!gmux_data)
return -ENOMEM;
pnp_set_drvdata(pnp, gmux_data);
switch (type) {
case APPLE_GMUX_TYPE_MMIO:
gmux_data->config = &apple_gmux_mmio;
mutex_init(&gmux_data->index_lock);
res = pnp_get_resource(pnp, IORESOURCE_MEM, 0);
gmux_data->iostart = res->start;
/* Although the ACPI table only allocates 8 bytes, we need 16. */
gmux_data->iolen = 16;
if (!request_mem_region(gmux_data->iostart, gmux_data->iolen,
"Apple gmux")) {
pr_err("gmux I/O already in use\n");
goto err_free;
}
gmux_data->iomem_base = ioremap(gmux_data->iostart, gmux_data->iolen);
if (!gmux_data->iomem_base) {
pr_err("couldn't remap gmux mmio region");
goto err_release;
}
goto get_version;
case APPLE_GMUX_TYPE_INDEXED:
gmux_data->config = &apple_gmux_index;
mutex_init(&gmux_data->index_lock);
break;
case APPLE_GMUX_TYPE_PIO:
gmux_data->config = &apple_gmux_pio;
break;
}
res = pnp_get_resource(pnp, IORESOURCE_IO, 0);
gmux_data->iostart = res->start;
gmux_data->iolen = resource_size(res);
if (!request_region(gmux_data->iostart, gmux_data->iolen,
"Apple gmux")) {
pr_err("gmux I/O already in use\n");
goto err_free;
}
get_version:
if (gmux_data->config->read_version_as_u32) {
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 {
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);
}
pr_info("Found gmux version %d.%d.%d [%s]\n", ver_major, ver_minor,
ver_release, gmux_data->config->name);
memset(&props, 0, sizeof(props));
props.type = BACKLIGHT_PLATFORM;
/*
* All MMIO gmux's have 0xffff as max brightness, but some iMacs incorrectly
* report 0x03ff, despite the firmware being happy to set 0xffff as the brightness
* at boot. Force 0xffff for all MMIO gmux's so they all have the correct brightness
* range.
*/
if (type == APPLE_GMUX_TYPE_MMIO)
props.max_brightness = MMIO_GMUX_MAX_BRIGHTNESS;
else
props.max_brightness = gmux_read32(gmux_data, GMUX_PORT_MAX_BRIGHTNESS);
#if IS_REACHABLE(CONFIG_ACPI_VIDEO)
register_bdev = acpi_video_get_backlight_type() == acpi_backlight_apple_gmux;
#endif
if (register_bdev) {
/*
* 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_unmap;
}
gmux_data->bdev = bdev;
bdev->props.brightness = gmux_get_brightness(bdev);
backlight_update_status(bdev);
}
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" or "T2" gmux.
*
* Pre-retina MacBook Pros can switch the panel's DDC separately.
*/
ret = vga_switcheroo_register_handler(gmux_data->config->gmux_handler,
gmux_data->config->handler_flags);
if (ret) {
pr_err("Failed to register vga_switcheroo handler\n");
goto err_register_handler;
}
gmux_init_debugfs(gmux_data);
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_unmap:
if (gmux_data->iomem_base)
iounmap(gmux_data->iomem_base);
err_release:
if (gmux_data->config->resource_type == IORESOURCE_MEM)
release_mem_region(gmux_data->iostart, gmux_data->iolen);
else
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);
gmux_fini_debugfs(gmux_data);
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);
if (gmux_data->iomem_base) {
iounmap(gmux_data->iomem_base);
release_mem_region(gmux_data->iostart, gmux_data->iolen);
} else
release_region(gmux_data->iostart, gmux_data->iolen);
apple_gmux_data = NULL;
kfree(gmux_data);
}
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 <[email protected]>");
MODULE_DESCRIPTION("Apple Gmux Driver");
MODULE_LICENSE("GPL");
MODULE_DEVICE_TABLE(pnp, gmux_device_ids);
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