/* * Gmux driver for Apple laptops * * Copyright (C) Canonical Ltd. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include #include #include #include #include #include #include #include #include #include struct apple_gmux_data { unsigned long iostart; unsigned long iolen; struct backlight_device *bdev; }; /* * gmux port offsets. Many of these are not yet used, but may be in the * future, and it's useful to have them documented here anyhow. */ #define GMUX_PORT_VERSION_MAJOR 0x04 #define GMUX_PORT_VERSION_MINOR 0x05 #define GMUX_PORT_VERSION_RELEASE 0x06 #define GMUX_PORT_SWITCH_DISPLAY 0x10 #define GMUX_PORT_SWITCH_GET_DISPLAY 0x11 #define GMUX_PORT_INTERRUPT_ENABLE 0x14 #define GMUX_PORT_INTERRUPT_STATUS 0x16 #define GMUX_PORT_SWITCH_DDC 0x28 #define GMUX_PORT_SWITCH_EXTERNAL 0x40 #define GMUX_PORT_SWITCH_GET_EXTERNAL 0x41 #define GMUX_PORT_DISCRETE_POWER 0x50 #define GMUX_PORT_MAX_BRIGHTNESS 0x70 #define GMUX_PORT_BRIGHTNESS 0x74 #define GMUX_MIN_IO_LEN (GMUX_PORT_BRIGHTNESS + 4) #define GMUX_INTERRUPT_ENABLE 0xff #define GMUX_INTERRUPT_DISABLE 0x00 #define GMUX_INTERRUPT_STATUS_ACTIVE 0 #define GMUX_INTERRUPT_STATUS_DISPLAY (1 << 0) #define GMUX_INTERRUPT_STATUS_POWER (1 << 2) #define GMUX_INTERRUPT_STATUS_HOTPLUG (1 << 3) #define GMUX_BRIGHTNESS_MASK 0x00ffffff #define GMUX_MAX_BRIGHTNESS GMUX_BRIGHTNESS_MASK static inline u8 gmux_read8(struct apple_gmux_data *gmux_data, int port) { return inb(gmux_data->iostart + port); } static inline void gmux_write8(struct apple_gmux_data *gmux_data, int port, u8 val) { outb(val, gmux_data->iostart + port); } static inline u32 gmux_read32(struct apple_gmux_data *gmux_data, int port) { return inl(gmux_data->iostart + port); } static inline u32 gmux_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, port + i); } } static int gmux_get_brightness(struct backlight_device *bd) { struct apple_gmux_data *gmux_data = bl_get_data(bd); return gmux_read32(gmux_data, GMUX_PORT_BRIGHTNESS) & GMUX_BRIGHTNESS_MASK; } static int gmux_update_status(struct backlight_device *bd) { struct apple_gmux_data *gmux_data = bl_get_data(bd); u32 brightness = bd->props.brightness; if (bd->props.state & BL_CORE_SUSPENDED) return 0; gmux_write32(gmux_data, GMUX_PORT_BRIGHTNESS, brightness); return 0; } static const struct backlight_ops gmux_bl_ops = { .options = BL_CORE_SUSPENDRESUME, .get_brightness = gmux_get_brightness, .update_status = gmux_update_status, }; static int __devinit gmux_probe(struct pnp_dev *pnp, const struct pnp_device_id *id) { struct apple_gmux_data *gmux_data; struct resource *res; struct backlight_properties props; struct backlight_device *bdev; u8 ver_major, ver_minor, ver_release; int ret = -ENXIO; gmux_data = kzalloc(sizeof(*gmux_data), GFP_KERNEL); if (!gmux_data) return -ENOMEM; pnp_set_drvdata(pnp, gmux_data); res = pnp_get_resource(pnp, IORESOURCE_IO, 0); if (!res) { pr_err("Failed to find gmux I/O resource\n"); goto err_free; } gmux_data->iostart = res->start; gmux_data->iolen = res->end - res->start; if (gmux_data->iolen < GMUX_MIN_IO_LEN) { pr_err("gmux I/O region too small (%lu < %u)\n", gmux_data->iolen, GMUX_MIN_IO_LEN); goto err_free; } if (!request_region(gmux_data->iostart, gmux_data->iolen, "Apple gmux")) { pr_err("gmux I/O already in use\n"); goto err_free; } /* * On some machines the gmux is in ACPI even thought the machine * doesn't really have a gmux. Check for invalid version information * to detect this. */ ver_major = gmux_read8(gmux_data, GMUX_PORT_VERSION_MAJOR); ver_minor = gmux_read8(gmux_data, GMUX_PORT_VERSION_MINOR); ver_release = gmux_read8(gmux_data, GMUX_PORT_VERSION_RELEASE); if (ver_major == 0xff && ver_minor == 0xff && ver_release == 0xff) { pr_info("gmux device not present\n"); ret = -ENODEV; goto err_release; } pr_info("Found gmux version %d.%d.%d\n", ver_major, ver_minor, ver_release); memset(&props, 0, sizeof(props)); props.type = BACKLIGHT_PLATFORM; props.max_brightness = gmux_read32(gmux_data, GMUX_PORT_MAX_BRIGHTNESS); /* * Currently it's assumed that the maximum brightness is less than * 2^24 for compatibility with old gmux versions. Cap the max * brightness at this value, but print a warning if the hardware * reports something higher so that it can be fixed. */ if (WARN_ON(props.max_brightness > GMUX_MAX_BRIGHTNESS)) props.max_brightness = GMUX_MAX_BRIGHTNESS; bdev = backlight_device_register("gmux_backlight", &pnp->dev, gmux_data, &gmux_bl_ops, &props); if (IS_ERR(bdev)) { ret = PTR_ERR(bdev); goto err_release; } gmux_data->bdev = bdev; bdev->props.brightness = gmux_get_brightness(bdev); backlight_update_status(bdev); /* * The backlight situation on Macs is complicated. If the gmux is * present it's the best choice, because it always works for * backlight control and supports more levels than other options. * Disable the other backlight choices. */ acpi_video_dmi_promote_vendor(); #ifdef CONFIG_ACPI_VIDEO acpi_video_unregister(); #endif apple_bl_unregister(); return 0; err_release: release_region(gmux_data->iostart, gmux_data->iolen); err_free: kfree(gmux_data); return ret; } static void __devexit gmux_remove(struct pnp_dev *pnp) { struct apple_gmux_data *gmux_data = pnp_get_drvdata(pnp); backlight_device_unregister(gmux_data->bdev); release_region(gmux_data->iostart, gmux_data->iolen); kfree(gmux_data); acpi_video_dmi_demote_vendor(); #ifdef CONFIG_ACPI_VIDEO acpi_video_register(); #endif apple_bl_register(); } static const struct pnp_device_id gmux_device_ids[] = { {"APP000B", 0}, {"", 0} }; static struct pnp_driver gmux_pnp_driver = { .name = "apple-gmux", .probe = gmux_probe, .remove = __devexit_p(gmux_remove), .id_table = gmux_device_ids, }; static int __init apple_gmux_init(void) { return pnp_register_driver(&gmux_pnp_driver); } static void __exit apple_gmux_exit(void) { pnp_unregister_driver(&gmux_pnp_driver); } module_init(apple_gmux_init); module_exit(apple_gmux_exit); MODULE_AUTHOR("Seth Forshee "); MODULE_DESCRIPTION("Apple Gmux Driver"); MODULE_LICENSE("GPL"); MODULE_DEVICE_TABLE(pnp, gmux_device_ids);