commit 82cb834240bbe0c7cdb1fe7356d075df8ddeae6b Author: Lekensteyn Date: Tue Nov 1 20:01:12 2011 +0100 Initial addition of bbswitch (WIP!) diff --git a/Makefile b/Makefile new file mode 100644 index 0000000..3e3adeb --- /dev/null +++ b/Makefile @@ -0,0 +1,15 @@ +obj-m := bbswitch.o + +KVERSION := $(shell uname -r) +KDIR := /lib/modules/$(KVERSION)/build +PWD := $(shell pwd) + +default: + $(MAKE) -C $(KDIR) M=$(PWD) modules + +clean: + $(MAKE) -C $(KDIR) M=$(PWD) clean + +load: + -/sbin/rmmod bbswitch + /sbin/insmod bbswitch.ko diff --git a/bbswitch.c b/bbswitch.c new file mode 100644 index 0000000..5ce7c70 --- /dev/null +++ b/bbswitch.c @@ -0,0 +1,193 @@ +/** + * Disable discrete graphics (currently nvidia only) + * + * Based on: + * byo-switcheroo Alex Williamson + * acpi_call Michal Kottman + */ +#include +#include +#include +#include + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("Toggle the discrete graphics card"); + +extern struct proc_dir_entry *acpi_root_dir; + +static const char acpi_optimus_dsm_muid[] = { + 0xF8, 0xD8, 0x86, 0xA4, 0xDA, 0x0B, 0x1B, 0x47, + 0xA7, 0x2B, 0x60, 0x42, 0xA6, 0xB5, 0xBE, 0xE0, +}; + +static struct pci_dev *dis_dev; +static acpi_handle dis_handle; +static int dis_enabled = 0; + +/* shamelessly taken from nouveau_acpi.c */ +static int acpi_optimus_dsm(acpi_handle handle, int func, char *args, + uint32_t *result) { + struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL }; + struct acpi_object_list input; + union acpi_object params[4]; + union acpi_object *obj; + int err; + + input.count = 4; + input.pointer = params; + params[0].type = ACPI_TYPE_BUFFER; + params[0].buffer.length = sizeof(acpi_optimus_dsm_muid); + params[0].buffer.pointer = (char *)acpi_optimus_dsm_muid; + params[1].type = ACPI_TYPE_INTEGER; + params[1].integer.value = 0x00000100; + params[2].type = ACPI_TYPE_INTEGER; + params[2].integer.value = func; + params[3].type = ACPI_TYPE_BUFFER; + params[3].buffer.length = sizeof(args); + params[3].buffer.pointer = args; + + err = acpi_evaluate_object(handle, "_DSM", &input, &output); + if (err) { + printk(KERN_WARNING "bbswitch: failed to evaluate _DSM: %s\n", + acpi_format_exception(err)); + return err; + } + + obj = (union acpi_object *)output.pointer; + + if (obj->type == ACPI_TYPE_INTEGER) + // REVS (revision number) not found, possibly not an Optimus? + if (obj->integer.value == 0x80000002) { + printk(KERN_INFO "bbswitch: Optimus function not found\n"); + return -ENODEV; + } + + if (obj->type == ACPI_TYPE_BUFFER) { + if (obj->buffer.length == 4 && result) { + *result = 0; + *result |= obj->buffer.pointer[0]; + *result |= (obj->buffer.pointer[1] << 8); + *result |= (obj->buffer.pointer[2] << 16); + *result |= (obj->buffer.pointer[3] << 24); + } + } + + kfree(output.pointer); + return 0; +} + +static void bbswitch_acpi_off(void) { + char args[] = {1, 0, 0, 3}; + u32 result = 0; + + if (!acpi_optimus_dsm(dis_handle, 0x1A, args, &result)) { + printk(KERN_INFO "bbswitch: Result of _DSM call: %08X\n", result); + } +} +static void bbswitch_acpi_on(void) { + +} + +static void bbswitch_off(void) { + if (dis_enabled) + return; + + printk(KERN_INFO "bbswitch: disabling discrete graphics\n"); + + pci_save_state(dis_dev); + pci_clear_master(dis_dev); + pci_disable_device(dis_dev); + pci_set_power_state(dis_dev, PCI_D3hot); + + bbswitch_acpi_off(); +} + +static void bbswitch_on(void) { + if (!dis_enabled) + return; + + printk(KERN_INFO "bbswitch: enabling discrete graphics\n"); + + bbswitch_acpi_on(); + + pci_set_power_state(dis_dev, PCI_D0); + pci_restore_state(dis_dev); + if (pci_enable_device(dis_dev)) + printk(KERN_WARNING "bbswitch: failed to enable %s\n", + dev_name(&dis_dev->dev)); + pci_set_master(dis_dev); +} + +static int bbswitch_write(struct file *filp, const char __user *buff, + unsigned long len, void *data) { + char cmd[8]; + + if (len >= sizeof(cmd)) { + printk(KERN_ERR "bbswitch: Input too large (%lu)\n", len); + return -ENOSPC; + } + + if (copy_from_user(cmd, buff, len)) + return -EFAULT; + + if (strncmp(cmd, "OFF", 3) == 0) + bbswitch_off(); + + if (strncmp(cmd, "ON", 2) == 0) + bbswitch_on(); + + return len; +} + +static int bbswitch_read(char *page, char **start, off_t off, + int count, int *eof, void *data) { + int len = 0; + return len; +} + +static int __init bbswitch_init(void) { + struct proc_dir_entry *acpi_entry; + struct pci_dev *pdev = NULL; + int class = PCI_CLASS_DISPLAY_VGA << 8; + + while ((pdev = pci_get_class(class, pdev)) != NULL) { + struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER, NULL }; + acpi_handle handle; + + handle = DEVICE_ACPI_HANDLE(&pdev->dev); + if (!handle) + continue; + + if (pdev->vendor != PCI_VENDOR_ID_INTEL) { + dis_dev = pdev; + dis_handle = handle; + } + acpi_get_name(handle, ACPI_FULL_PATHNAME, &buf); + printk(KERN_INFO "bbswitch: Found discrete VGA device %s: %s\n", + dev_name(&pdev->dev), (char *)buf.pointer); + kfree(buf.pointer); + } + + if (dis_dev == NULL) { + printk(KERN_ERR "bbswitch: No discrete VGA device found\n"); + return -ENODEV; + } + + acpi_entry = create_proc_entry("bbswitch", 0660, acpi_root_dir); + if (acpi_entry == NULL) { + printk(KERN_ERR "bbswitch: Couldn't create proc entry\n"); + return -ENOMEM; + } + + acpi_entry->write_proc = bbswitch_write; + acpi_entry->read_proc = bbswitch_read; + + return 0; +} + +static void __exit bbswitch_exit(void) { + remove_proc_entry("bbswitch", acpi_root_dir); +} + +module_init(bbswitch_init); +module_exit(bbswitch_exit);