omap: add hwspinlock device

Build and register an hwspinlock platform device.

Although only OMAP4 supports the hardware spinlock module (for now),
it is still safe to run this initcall on all omaps, because hwmod lookup
will simply fail on hwspinlock-less platforms.
Signed-off-by: Simon Que <sque@ti.com>
Signed-off-by: Hari Kanigeri <h-kanigeri2@ti.com>
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Cc: Benoit Cousson <b-cousson@ti.com>
Cc: Kevin Hilman <khilman@ti.com>
Cc: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/mach-omap2/Makefile

@@ -243,3 +243,4 @@ obj-y					+= $(smc91x-m) $(smc91x-y)
 
 smsc911x-$(CONFIG_SMSC911X)		:= gpmc-smsc911x.o
 obj-y					+= $(smsc911x-m) $(smsc911x-y)
+obj-$(CONFIG_ARCH_OMAP4)		+= hwspinlock.o

arch/arm/mach-omap2/hwspinlock.c

+/*
+ * OMAP hardware spinlock device initialization
+ *
+ * Copyright (C) 2010 Texas Instruments Incorporated - http://www.ti.com
+ *
+ * Contact: Simon Que <sque@ti.com>
+ *          Hari Kanigeri <h-kanigeri2@ti.com>
+ *
+ * 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.
+ *
+ * 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.
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/err.h>
+
+#include <plat/omap_hwmod.h>
+#include <plat/omap_device.h>
+
+struct omap_device_pm_latency omap_spinlock_latency[] = {
+	{
+		.deactivate_func = omap_device_idle_hwmods,
+		.activate_func   = omap_device_enable_hwmods,
+		.flags = OMAP_DEVICE_LATENCY_AUTO_ADJUST,
+	}
+};
+
+int __init hwspinlocks_init(void)
+{
+	int retval = 0;
+	struct omap_hwmod *oh;
+	struct omap_device *od;
+	const char *oh_name = "spinlock";
+	const char *dev_name = "omap_hwspinlock";
+
+	/*
+	 * Hwmod lookup will fail in case our platform doesn't support the
+	 * hardware spinlock module, so it is safe to run this initcall
+	 * on all omaps
+	 */
+	oh = omap_hwmod_lookup(oh_name);
+	if (oh == NULL)
+		return -EINVAL;
+
+	od = omap_device_build(dev_name, 0, oh, NULL, 0,
+				omap_spinlock_latency,
+				ARRAY_SIZE(omap_spinlock_latency), false);
+	if (IS_ERR(od)) {
+		pr_err("Can't build omap_device for %s:%s\n", dev_name,
+								oh_name);
+		retval = PTR_ERR(od);
+	}
+
+	return retval;
+}
+/* early board code might need to reserve specific hwspinlock instances */
+postcore_initcall(hwspinlocks_init);