platform/x86: add MXM WMI driver.

MXM is a laptop graphics card form-factor + interface specification,
this adds an initial stub driver to talk to the MXM WMI interface.

The only method used is the MUX switching method needed to do switchable
graphics on the nvidia chipsets.
Signed-off-by: NDave Airlie <airlied@redhat.com>
Acked-by: NMatthew Garrett <mjg@redhat.com>

drivers/platform/x86/Kconfig

@@ -753,4 +753,11 @@ config SAMSUNG_LAPTOP
 	  To compile this driver as a module, choose M here: the module
 	  will be called samsung-laptop.
 
+config MXM_WMI
+       tristate "WMI support for MXM Laptop Graphics"
+       depends on WMI
+       ---help---
+          MXM is a standard for laptop graphics cards, the WMI interface
+	  is required for switchable nvidia graphics machines
+
 endif # X86_PLATFORM_DEVICES

drivers/platform/x86/Makefile

@@ -42,3 +42,4 @@ obj-$(CONFIG_XO15_EBOOK)	+= xo15-ebook.o
 obj-$(CONFIG_IBM_RTL)		+= ibm_rtl.o
 obj-$(CONFIG_SAMSUNG_LAPTOP)	+= samsung-laptop.o
 obj-$(CONFIG_INTEL_MFLD_THERMAL)	+= intel_mid_thermal.o
+obj-$(CONFIG_MXM_WMI)		+= mxm-wmi.o

drivers/platform/x86/mxm-wmi.c

+/*
+ * MXM WMI driver
+ *
+ * Copyright(C) 2010 Red Hat.
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <acpi/acpi_bus.h>
+#include <acpi/acpi_drivers.h>
+
+MODULE_AUTHOR("Dave Airlie");
+MODULE_DESCRIPTION("MXM WMI Driver");
+MODULE_LICENSE("GPL");
+
+#define MXM_WMMX_GUID "F6CB5C3C-9CAE-4EBD-B577-931EA32A2CC0"
+
+MODULE_ALIAS("wmi:"MXM_WMMX_GUID);
+
+#define MXM_WMMX_FUNC_MXDS 0x5344584D /* "MXDS" */
+
+struct mxds_args {
+	u32 func;
+	u32 args;
+	u32 xarg;
+};
+
+int mxm_wmi_call_mxds(int adapter)
+{
+	struct mxds_args args = {
+		.func = MXM_WMMX_FUNC_MXDS,
+		.args = 0,
+		.xarg = 1,
+	};
+	struct acpi_buffer input = { (acpi_size)sizeof(args), &args };
+	struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
+	acpi_status status;
+
+	printk("calling mux switch %d\n", adapter);
+	
+	status = wmi_evaluate_method(MXM_WMMX_GUID, 0x1, adapter, &input,
+				     &output);
+
+	if (ACPI_FAILURE(status))
+		return status;
+
+	printk("mux switched %d\n", status);
+	return 0;
+			    
+}
+EXPORT_SYMBOL_GPL(mxm_wmi_call_mxds);
+
+bool mxm_wmi_supported(void)
+{
+	bool guid_valid;
+	guid_valid = wmi_has_guid(MXM_WMMX_GUID);
+	return guid_valid;
+}
+EXPORT_SYMBOL_GPL(mxm_wmi_supported);
+
+static int __init mxm_wmi_init(void)
+{
+	return 0;
+}
+
+static void __exit mxm_wmi_exit(void)
+{
+}
+
+module_init(mxm_wmi_init);
+module_exit(mxm_wmi_exit);

include/linux/mxm-wmi.h

+/*
+ * MXM WMI driver
+ *
+ * Copyright(C) 2010 Red Hat.
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#ifndef MXM_WMI_H
+#define MXM_WMI_H
+
+/* discrete adapters */
+#define MXM_MXDS_ADAPTER_0 0x0
+#define MXM_MXDS_ADAPTER_1 0x0
+/* integrated adapter */
+#define MXM_MXDS_ADAPTER_IGD 0x10
+int mxm_wmi_call_mxds(int adapter);
+bool mxm_wmi_supported(void);
+
+#endif