gta02: Add wlan power management device

1 files changed, 201 insertions, 0 deletions

diff --git a/arch/arm/mach-s3c2440/gta02-pm-wlan.c b/arch/arm/mach-s3c2440/gta02-pm-wlan.c
new file mode 100644
index 00000000000..c6ae6f3ced8
--- /dev/null
+++ b/arch/arm/mach-s3c2440/gta02-pm-wlan.c
@@ -0,0 +1,201 @@
+/*
+ * GTA02 WLAN power management
+ *
+ * (C) 2008, 2009 by Openmoko Inc.
+ * Author: Andy Green <andy@openmoko.com>
+ * All rights reserved.
+ *
+ * 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
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/mutex.h>
+#include <linux/platform_device.h>
+
+#include <mach/hardware.h>
+#include <asm/mach-types.h>
+
+#include <mach/gta02.h>
+#include <mach/gta02-pm-wlan.h>
+#include <mach/regs-gpio.h>
+#include <mach/regs-gpioj.h>
+#include <mach/gpio-fns.h>
+
+#include <linux/delay.h>
+#include <linux/rfkill.h>
+
+
+/* ----- Module hardware reset ("power") ----------------------------------- */
+
+
+void gta02_wlan_reset(int assert_reset)
+{
+	if (assert_reset) {
+		s3c2410_gpio_setpin(GTA02_GPIO_nWLAN_RESET, 0);
+		msleep(200); /* probably excessive but we don't have specs */
+	} else {
+		s3c2410_gpio_setpin(GTA02_GPIO_nWLAN_RESET, 1);
+	}
+}
+
+/* ----- rfkill ------------------------------------------------------------ */
+
+/*
+ * S3C MCI handles suspend/resume through device removal/insertion. In order to
+ * preserve rfkill state, as required in clause 7 of section 3.1 in rfkill.txt,
+ * we therefore need to maintain rfkill state outside the driver.
+ *
+ * This platform driver is as good a place as any other.
+ */
+
+static int (*gta02_wlan_rfkill_cb)(void *user, int on);
+static void *gta02_wlan_rfkill_user;
+static DEFINE_MUTEX(gta02_wlan_rfkill_lock);
+static int gta02_wlan_rfkill_on;
+
+/*
+ * gta02_wlan_query_rfkill_lock is used to obtain the rfkill state before the
+ * driver is ready to process rfkill callbacks. To prevent the state from
+ * changing until the driver has completed its initialization, we grab and hold
+ * the rfkill lock.
+ *
+ * A call to gta02_wlan_query_rfkill_lock must be followed by either
+ * - a call to gta02_wlan_set_rfkill_cb, to complete the setup, or
+ * - a call to gta02_wlan_query_rfkill_unlock to abort the setup process.
+ */
+
+int gta02_wlan_query_rfkill_lock(void)
+{
+	mutex_lock(&gta02_wlan_rfkill_lock);
+	return gta02_wlan_rfkill_on;
+}
+EXPORT_SYMBOL_GPL(gta02_wlan_query_rfkill_lock);
+
+void gta02_wlan_query_rfkill_unlock(void)
+{
+	mutex_unlock(&gta02_wlan_rfkill_lock);
+}
+EXPORT_SYMBOL_GPL(gta02_wlan_query_rfkill_unlock);
+
+void gta02_wlan_set_rfkill_cb(int (*cb)(void *user, int on), void *user)
+{
+	BUG_ON(!mutex_is_locked(&gta02_wlan_rfkill_lock));
+	BUG_ON(gta02_wlan_rfkill_cb);
+	gta02_wlan_rfkill_cb = cb;
+	gta02_wlan_rfkill_user = user;
+	mutex_unlock(&gta02_wlan_rfkill_lock);
+}
+EXPORT_SYMBOL_GPL(gta02_wlan_set_rfkill_cb);
+
+void gta02_wlan_clear_rfkill_cb(void)
+{
+	mutex_lock(&gta02_wlan_rfkill_lock);
+	BUG_ON(!gta02_wlan_rfkill_cb);
+	gta02_wlan_rfkill_cb = NULL;
+	mutex_unlock(&gta02_wlan_rfkill_lock);
+}
+EXPORT_SYMBOL_GPL(gta02_wlan_clear_rfkill_cb);
+
+static int gta02_wlan_set_radio_block(void *data, bool blocked)
+{
+	struct device *dev = data;
+	int res = 0;
+
+	dev_dbg(dev, "gta02_wlan_toggle_radio: blocked %d (%p)\n",
+	    blocked, gta02_wlan_rfkill_cb);
+	mutex_lock(&gta02_wlan_rfkill_lock);
+	if (gta02_wlan_rfkill_cb)
+		res = gta02_wlan_rfkill_cb(gta02_wlan_rfkill_user, !blocked);
+	if (!res)
+		gta02_wlan_rfkill_on = !blocked;
+	mutex_unlock(&gta02_wlan_rfkill_lock);
+	return res;
+}
+
+static const struct rfkill_ops gta02_wlan_rfkill_ops = {
+       .set_block = gta02_wlan_set_radio_block,
+};
+
+/* ----- Initialization/removal -------------------------------------------- */
+
+
+static int __init gta02_wlan_probe(struct platform_device *pdev)
+{
+	/* default-on for now */
+	const int default_state = 1;
+	struct rfkill *rfkill;
+	int ret;
+
+	dev_info(&pdev->dev, "starting\n");
+
+	s3c2410_gpio_cfgpin(GTA02_GPIO_nWLAN_RESET, S3C2410_GPIO_OUTPUT);
+	gta02_wlan_reset(1);
+	gta02_wlan_reset(0);
+
+	rfkill = rfkill_alloc("ar6000", &pdev->dev, RFKILL_TYPE_WLAN,
+							&gta02_wlan_rfkill_ops, &pdev->dev);
+
+
+	if (!rfkill) {
+		dev_err(&pdev->dev, "Failed to allocate rfkill\n");
+		return -ENOMEM;
+	}
+
+	rfkill_init_sw_state(rfkill, default_state);
+	/*
+	 * If the WLAN driver somehow managed to get activated before we're
+	 * ready, the driver is now in an unknown state, which isn't something
+	 * we're prepared to handle. This can't happen, so just fail hard.
+	 */
+	BUG_ON(gta02_wlan_rfkill_cb);
+	gta02_wlan_rfkill_on = default_state;
+
+	ret = rfkill_register(rfkill);
+	if (ret) {
+		rfkill_destroy(rfkill);
+		dev_err(&pdev->dev, "Failed to register rfkill\n");
+		return ret;
+	}
+
+	dev_set_drvdata(&pdev->dev, rfkill);
+
+	return 0;
+}
+
+static int gta02_wlan_remove(struct platform_device *pdev)
+{
+	struct rfkill *rfkill = dev_get_drvdata(&pdev->dev);
+
+	rfkill_destroy(rfkill);
+
+	return 0;
+}
+
+static struct platform_driver gta02_wlan_driver = {
+	.probe		= gta02_wlan_probe,
+	.remove		= gta02_wlan_remove,
+	.driver		= {
+		.name		= "gta02-pm-wlan",
+	},
+};
+
+static int __devinit gta02_wlan_init(void)
+{
+	return platform_driver_register(&gta02_wlan_driver);
+}
+module_init(gta02_wlan_init);
+
+static void gta02_wlan_exit(void)
+{
+	platform_driver_unregister(&gta02_wlan_driver);
+}
+module_exit(gta02_wlan_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Andy Green <andy@openmoko.com>");
+MODULE_DESCRIPTION("Openmoko GTA02 WLAN power management");