1 files changed, 151 insertions, 0 deletions
diff --git a/drivers/remoteproc/remoteproc_sysfs.c b/drivers/remoteproc/remoteproc_sysfs.c
new file mode 100644
index 000000000000..bc5b0e00efb1
--- /dev/null
+++ b/drivers/remoteproc/remoteproc_sysfs.c
@@ -0,0 +1,151 @@
+/*
+ * Remote Processor Framework
+ *
+ * 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/remoteproc.h>
+
+#include "remoteproc_internal.h"
+
+#define to_rproc(d) container_of(d, struct rproc, dev)
+
+/* Expose the loaded / running firmware name via sysfs */
+static ssize_t firmware_show(struct device *dev, struct device_attribute *attr,
+			  char *buf)
+{
+	struct rproc *rproc = to_rproc(dev);
+
+	return sprintf(buf, "%s\n", rproc->firmware);
+}
+
+/* Change firmware name via sysfs */
+static ssize_t firmware_store(struct device *dev,
+			      struct device_attribute *attr,
+			      const char *buf, size_t count)
+{
+	struct rproc *rproc = to_rproc(dev);
+	char *p;
+	int err, len = count;
+
+	err = mutex_lock_interruptible(&rproc->lock);
+	if (err) {
+		dev_err(dev, "can't lock rproc %s: %d\n", rproc->name, err);
+		return -EINVAL;
+	}
+
+	if (rproc->state != RPROC_OFFLINE) {
+		dev_err(dev, "can't change firmware while running\n");
+		err = -EBUSY;
+		goto out;
+	}
+
+	len = strcspn(buf, "\n");
+
+	p = kstrndup(buf, len, GFP_KERNEL);
+	if (!p) {
+		err = -ENOMEM;
+		goto out;
+	}
+
+	kfree(rproc->firmware);
+	rproc->firmware = p;
+out:
+	mutex_unlock(&rproc->lock);
+
+	return err ? err : count;
+}
+static DEVICE_ATTR_RW(firmware);
+
+/*
+ * A state-to-string lookup table, for exposing a human readable state
+ * via sysfs. Always keep in sync with enum rproc_state
+ */
+static const char * const rproc_state_string[] = {
+	[RPROC_OFFLINE]		= "offline",
+	[RPROC_SUSPENDED]	= "suspended",
+	[RPROC_RUNNING]		= "running",
+	[RPROC_CRASHED]		= "crashed",
+	[RPROC_LAST]		= "invalid",
+};
+
+/* Expose the state of the remote processor via sysfs */
+static ssize_t state_show(struct device *dev, struct device_attribute *attr,
+			  char *buf)
+{
+	struct rproc *rproc = to_rproc(dev);
+	unsigned int state;
+
+	state = rproc->state > RPROC_LAST ? RPROC_LAST : rproc->state;
+	return sprintf(buf, "%s\n", rproc_state_string[state]);
+}
+
+/* Change remote processor state via sysfs */
+static ssize_t state_store(struct device *dev,
+			      struct device_attribute *attr,
+			      const char *buf, size_t count)
+{
+	struct rproc *rproc = to_rproc(dev);
+	int ret = 0;
+
+	if (sysfs_streq(buf, "start")) {
+		if (rproc->state == RPROC_RUNNING)
+			return -EBUSY;
+
+		ret = rproc_boot(rproc);
+		if (ret)
+			dev_err(&rproc->dev, "Boot failed: %d\n", ret);
+	} else if (sysfs_streq(buf, "stop")) {
+		if (rproc->state != RPROC_RUNNING)
+			return -EINVAL;
+
+		rproc_shutdown(rproc);
+	} else {
+		dev_err(&rproc->dev, "Unrecognised option: %s\n", buf);
+		ret = -EINVAL;
+	}
+	return ret ? ret : count;
+}
+static DEVICE_ATTR_RW(state);
+
+static struct attribute *rproc_attrs[] = {
+	&dev_attr_firmware.attr,
+	&dev_attr_state.attr,
+	NULL
+};
+
+static const struct attribute_group rproc_devgroup = {
+	.attrs = rproc_attrs
+};
+
+static const struct attribute_group *rproc_devgroups[] = {
+	&rproc_devgroup,
+	NULL
+};
+
+struct class rproc_class = {
+	.name		= "remoteproc",
+	.dev_groups	= rproc_devgroups,
+};
+
+int __init rproc_init_sysfs(void)
+{
+	/* create remoteproc device class for sysfs */
+	int err = class_register(&rproc_class);
+
+	if (err)
+		pr_err("remoteproc: unable to register class\n");
+	return err;
+}
+
+void __exit rproc_exit_sysfs(void)
+{
+	class_unregister(&rproc_class);
+}