// SPDX-License-Identifier: GPL-2.0-only /* * Gmux driver for Apple laptops * * Copyright (C) Canonical Ltd. * Copyright (C) 2010-2012 Andreas Heider * Copyright (C) 2015 Lukas Wunner * Copyright (C) 2023 Orlando Chamberlain */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include #include #include #include #include #include #include #include #include #include #include #include #include #include /** * 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 "); MODULE_DESCRIPTION("Apple Gmux Driver"); MODULE_LICENSE("GPL"); MODULE_DEVICE_TABLE(pnp, gmux_device_ids);