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>

3 files changed, 94 insertions, 0 deletions

diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index d2d15108ce4b..91e431b6f20f 100644
--- a/drivers/platform/x86/Kconfig
+++ b/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
diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
index c97ac2a9dab7..c15e96336e65 100644
--- a/drivers/platform/x86/Makefile
+++ b/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
 
diff --git a/drivers/platform/x86/xo1-rfkill.c b/drivers/platform/x86/xo1-rfkill.c
new file mode 100644
index 000000000000..e549eeeda121
--- /dev/null
+++ b/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);