Add OLPC XO-1 rfkill driver

Add a software rfkill switch for the WLAN interface in the OLPC XO-1
laptop. It uses the OLPC embedded controller to cut/restore power to
the Marvell WLAN chip on the motherboard.

Signed-off-by: Daniel Drake <dsd@laptop.org>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

arch/x86/include/asm/olpc.h

@@ -89,6 +89,8 @@ extern int olpc_ec_mask_unset(uint8_t bits);
 /* EC commands */
 
 #define EC_FIRMWARE_REV		0x08
+#define EC_WLAN_ENTER_RESET	0x35
+#define EC_WLAN_LEAVE_RESET	0x25
 
 /* SCI source values */
 

drivers/platform/x86/Kconfig

@@ -615,4 +615,12 @@ config INTEL_IPS
 	  functionality.  If in doubt, say Y here; it will only load on
 	  supported platforms.
 
+config XO1_RFKILL
+	tristate "OLPC XO-1 software RF kill switch"
+	depends on OLPC
+	depends on RFKILL
+	---help---
+	  Support for enabling/disabling the WLAN interface on the OLPC XO-1
+	  laptop.
+
 endif # X86_PLATFORM_DEVICES

drivers/platform/x86/Makefile

@@ -31,4 +31,5 @@ obj-$(CONFIG_INTEL_SCU_IPC)	+= intel_scu_ipc.o
 obj-$(CONFIG_RAR_REGISTER)	+= intel_rar_register.o
 obj-$(CONFIG_INTEL_IPS)		+= intel_ips.o
 obj-$(CONFIG_GPIO_INTEL_PMIC)	+= intel_pmic_gpio.o
+obj-$(CONFIG_XO1_RFKILL)	+= xo1-rfkill.o
 

drivers/platform/x86/xo1-rfkill.c

@@ -0,0 +1,85 @@
+/*
+ * Support for rfkill through the OLPC XO-1 laptop embedded controller
+ *
+ * Copyright (C) 2010 One Laptop per Child
+ *
+ * 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.
+ */
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/rfkill.h>
+
+#include <asm/olpc.h>
+
+static int rfkill_set_block(void *data, bool blocked)
+{
+	unsigned char cmd;
+	if (blocked)
+		cmd = EC_WLAN_ENTER_RESET;
+	else
+		cmd = EC_WLAN_LEAVE_RESET;
+
+	return olpc_ec_cmd(cmd, NULL, 0, NULL, 0);
+}
+
+static const struct rfkill_ops rfkill_ops = {
+	.set_block = rfkill_set_block,
+};
+
+static int __devinit xo1_rfkill_probe(struct platform_device *pdev)
+{
+	struct rfkill *rfk;
+	int r;
+
+	rfk = rfkill_alloc(pdev->name, &pdev->dev, RFKILL_TYPE_WLAN,
+			   &rfkill_ops, NULL);
+	if (!rfk)
+		return -ENOMEM;
+
+	r = rfkill_register(rfk);
+	if (r) {
+		rfkill_destroy(rfk);
+		return r;
+	}
+
+	platform_set_drvdata(pdev, rfk);
+	return 0;
+}
+
+static int __devexit xo1_rfkill_remove(struct platform_device *pdev)
+{
+	struct rfkill *rfk = platform_get_drvdata(pdev);
+	rfkill_unregister(rfk);
+	rfkill_destroy(rfk);
+	return 0;
+}
+
+static struct platform_driver xo1_rfkill_driver = {
+	.driver = {
+		.name = "xo1-rfkill",
+		.owner = THIS_MODULE,
+	},
+	.probe		= xo1_rfkill_probe,
+	.remove		= __devexit_p(xo1_rfkill_remove),
+};
+
+static int __init xo1_rfkill_init(void)
+{
+	return platform_driver_register(&xo1_rfkill_driver);
+}
+
+static void __exit xo1_rfkill_exit(void)
+{
+	platform_driver_unregister(&xo1_rfkill_driver);
+}
+
+MODULE_AUTHOR("Daniel Drake <dsd@laptop.org>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:xo1-rfkill");
+
+module_init(xo1_rfkill_init);
+module_exit(xo1_rfkill_exit);