diff options
Diffstat (limited to 'drivers/platform/x86/apple-gmux.c')
| -rw-r--r-- | drivers/platform/x86/apple-gmux.c | 1039 |
1 files changed, 1039 insertions, 0 deletions
diff --git a/drivers/platform/x86/apple-gmux.c b/drivers/platform/x86/apple-gmux.c new file mode 100644 index 0000000000..1417e230ed --- /dev/null +++ b/drivers/platform/x86/apple-gmux.c @@ -0,0 +1,1039 @@ +// 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> + * Copyright (C) 2023 Orlando Chamberlain <orlandoch.dev@gmail.com> + */ + +#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 <seth.forshee@canonical.com>"); +MODULE_DESCRIPTION("Apple Gmux Driver"); +MODULE_LICENSE("GPL"); +MODULE_DEVICE_TABLE(pnp, gmux_device_ids); |