Merge tag 'for-v4.6-rc/omap-fixes-a' of git://git.kernel.org/pub/scm/linux/kernel/git/pjw/omap-pending into omap-for-v4.6/fixes

ARM: OMAP2+: first hwmod fix for v4.6-rc

Fix a longstanding bug in the hwmod code that could cause
hardware SYSCONFIG register values to not match the kernel's
idea of what they should be, and that could result in lower
performance during IP block idle entry.

Basic build, boot, and PM test logs are available here:

http://www.pwsan.com/omap/testlogs/omap-hwmod-fixes-a-for-v4.6-rc/20160326231727/

1 files changed, 130 insertions, 0 deletions

diff --git a/drivers/hwtracing/stm/heartbeat.c b/drivers/hwtracing/stm/heartbeat.c
new file mode 100644
index 000000000000..0133571b506f
--- /dev/null
+++ b/drivers/hwtracing/stm/heartbeat.c
@@ -0,0 +1,130 @@
+/*
+ * Simple heartbeat STM source driver
+ * Copyright (c) 2016, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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.
+ *
+ * Heartbeat STM source will send repetitive messages over STM devices to a
+ * trace host.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/hrtimer.h>
+#include <linux/slab.h>
+#include <linux/stm.h>
+
+#define STM_HEARTBEAT_MAX	32
+
+static int nr_devs = 4;
+static int interval_ms = 10;
+
+module_param(nr_devs, int, 0600);
+module_param(interval_ms, int, 0600);
+
+static struct stm_heartbeat {
+	struct stm_source_data	data;
+	struct hrtimer		hrtimer;
+	unsigned int		active;
+} stm_heartbeat[STM_HEARTBEAT_MAX];
+
+static unsigned int nr_instances;
+
+static const char str[] = "heartbeat stm source driver is here to serve you";
+
+static enum hrtimer_restart stm_heartbeat_hrtimer_handler(struct hrtimer *hr)
+{
+	struct stm_heartbeat *heartbeat = container_of(hr, struct stm_heartbeat,
+						       hrtimer);
+
+	stm_source_write(&heartbeat->data, 0, str, sizeof str);
+	if (heartbeat->active)
+		hrtimer_forward_now(hr, ms_to_ktime(interval_ms));
+
+	return heartbeat->active ? HRTIMER_RESTART : HRTIMER_NORESTART;
+}
+
+static int stm_heartbeat_link(struct stm_source_data *data)
+{
+	struct stm_heartbeat *heartbeat =
+		container_of(data, struct stm_heartbeat, data);
+
+	heartbeat->active = 1;
+	hrtimer_start(&heartbeat->hrtimer, ms_to_ktime(interval_ms),
+		      HRTIMER_MODE_ABS);
+
+	return 0;
+}
+
+static void stm_heartbeat_unlink(struct stm_source_data *data)
+{
+	struct stm_heartbeat *heartbeat =
+		container_of(data, struct stm_heartbeat, data);
+
+	heartbeat->active = 0;
+	hrtimer_cancel(&heartbeat->hrtimer);
+}
+
+static int stm_heartbeat_init(void)
+{
+	int i, ret = -ENOMEM, __nr_instances = ACCESS_ONCE(nr_devs);
+
+	if (__nr_instances < 0 || __nr_instances > STM_HEARTBEAT_MAX)
+		return -EINVAL;
+
+	for (i = 0; i < __nr_instances; i++) {
+		stm_heartbeat[i].data.name =
+			kasprintf(GFP_KERNEL, "heartbeat.%d", i);
+		if (!stm_heartbeat[i].data.name)
+			goto fail_unregister;
+
+		stm_heartbeat[i].data.nr_chans	= 1;
+		stm_heartbeat[i].data.link		= stm_heartbeat_link;
+		stm_heartbeat[i].data.unlink	= stm_heartbeat_unlink;
+		hrtimer_init(&stm_heartbeat[i].hrtimer, CLOCK_MONOTONIC,
+			     HRTIMER_MODE_ABS);
+		stm_heartbeat[i].hrtimer.function =
+			stm_heartbeat_hrtimer_handler;
+
+		ret = stm_source_register_device(NULL, &stm_heartbeat[i].data);
+		if (ret)
+			goto fail_free;
+	}
+
+	nr_instances = __nr_instances;
+
+	return 0;
+
+fail_unregister:
+	for (i--; i >= 0; i--) {
+		stm_source_unregister_device(&stm_heartbeat[i].data);
+fail_free:
+		kfree(stm_heartbeat[i].data.name);
+	}
+
+	return ret;
+}
+
+static void stm_heartbeat_exit(void)
+{
+	int i;
+
+	for (i = 0; i < nr_instances; i++) {
+		stm_source_unregister_device(&stm_heartbeat[i].data);
+		kfree(stm_heartbeat[i].data.name);
+	}
+}
+
+module_init(stm_heartbeat_init);
+module_exit(stm_heartbeat_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("stm_heartbeat driver");
+MODULE_AUTHOR("Alexander Shishkin <alexander.shishkin@linux.intel.com>");