remoteproc: add debugfs entries

obj-$(CONFIG_REMOTEPROC)		+= remoteproc.o

remoteproc-y				:= remoteproc_core.o

remoteproc-y				+= remoteproc_debugfs.o

/*

 * Remote Processor Framework

 *

 * Copyright (C) 2011 Texas Instruments, Inc.

 * Copyright (C) 2011 Google, Inc.

 *

 * Ohad Ben-Cohen <ohad@wizery.com>

 * Mark Grosen <mgrosen@ti.com>

 * Brian Swetland <swetland@google.com>

 * Fernando Guzman Lugo <fernando.lugo@ti.com>

 * Suman Anna <s-anna@ti.com>

 * Robert Tivy <rtivy@ti.com>

 * Armando Uribe De Leon <x0095078@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.

 */

#define pr_fmt(fmt)    "%s: " fmt, __func__

#include <linux/kernel.h>

#include <linux/debugfs.h>

#include <linux/remoteproc.h>

#include <linux/device.h>

/* remoteproc debugfs parent dir */

static struct dentry *rproc_dbg;

/*

 * Some remote processors may support dumping trace logs into a shared

 * memory buffer. We expose this trace buffer using debugfs, so users

 * can easily tell what's going on remotely.

 *

 * We will most probably improve the rproc tracing facilities later on,

 * but this kind of lightweight and simple mechanism is always good to have,

 * as it provides very early tracing with little to no dependencies at all.

 */

static ssize_t rproc_trace_read(struct file *filp, char __user *userbuf,

						size_t count, loff_t *ppos)

{

	struct rproc_mem_entry *trace = filp->private_data;

	int len = strnlen(trace->va, trace->len);

	return simple_read_from_buffer(userbuf, count, ppos, trace->va, len);

}

static int rproc_open_generic(struct inode *inode, struct file *file)

{

	file->private_data = inode->i_private;

	return 0;

}

static const struct file_operations trace_rproc_ops = {

	.read = rproc_trace_read,

	.open = rproc_open_generic,

	.llseek	= generic_file_llseek,

};

/*

 * A state-to-string lookup table, for exposing a human readable state

 * via debugfs. Always keep in sync with enum rproc_state

 */

static const char * const rproc_state_string[] = {

	"offline",

	"suspended",

	"running",

	"crashed",

	"invalid",

};

/* expose the state of the remote processor via debugfs */

static ssize_t rproc_state_read(struct file *filp, char __user *userbuf,

						size_t count, loff_t *ppos)

{

	struct rproc *rproc = filp->private_data;

	unsigned int state;

	char buf[30];

	int i;

	state = rproc->state > RPROC_LAST ? RPROC_LAST : rproc->state;

	i = snprintf(buf, 30, "%.28s (%d)\n", rproc_state_string[state],

							rproc->state);

	return simple_read_from_buffer(userbuf, count, ppos, buf, i);

}

static const struct file_operations rproc_state_ops = {

	.read = rproc_state_read,

	.open = rproc_open_generic,

	.llseek	= generic_file_llseek,

};

/* expose the name of the remote processor via debugfs */

static ssize_t rproc_name_read(struct file *filp, char __user *userbuf,

						size_t count, loff_t *ppos)

{

	struct rproc *rproc = filp->private_data;

	/* need room for the name, a newline and a terminating null */

	char buf[100];

	int i;

	i = snprintf(buf, sizeof(buf), "%.98s\n", rproc->name);

	return simple_read_from_buffer(userbuf, count, ppos, buf, i);

}

static const struct file_operations rproc_name_ops = {

	.read = rproc_name_read,

	.open = rproc_open_generic,

	.llseek	= generic_file_llseek,

};

void rproc_remove_trace_file(struct dentry *tfile)

{

	debugfs_remove(tfile);

}

struct dentry *rproc_create_trace_file(const char *name, struct rproc *rproc,

					struct rproc_mem_entry *trace)

{

	struct dentry *tfile;

	tfile = debugfs_create_file(name, 0400, rproc->dbg_dir,

						trace, &trace_rproc_ops);

	if (!tfile) {

		dev_err(rproc->dev, "failed to create debugfs trace entry\n");

		return NULL;

	}

	return tfile;

}

void rproc_delete_debug_dir(struct rproc *rproc)

{

	if (!rproc->dbg_dir)

		return;

	debugfs_remove_recursive(rproc->dbg_dir);

}

void rproc_create_debug_dir(struct rproc *rproc)

{

	struct device *dev = rproc->dev;

	if (!rproc_dbg)

		return;

	rproc->dbg_dir = debugfs_create_dir(dev_name(dev), rproc_dbg);

	if (!rproc->dbg_dir)

		return;

	debugfs_create_file("name", 0400, rproc->dbg_dir,

					rproc, &rproc_name_ops);

	debugfs_create_file("state", 0400, rproc->dbg_dir,

					rproc, &rproc_state_ops);

}

void __init rproc_init_debugfs(void)

{

	if (debugfs_initialized()) {

		rproc_dbg = debugfs_create_dir(KBUILD_MODNAME, NULL);

		if (!rproc_dbg)

			pr_err("can't create debugfs dir\n");

	}

}

void __exit rproc_exit_debugfs(void)

{

	if (rproc_dbg)

		debugfs_remove(rproc_dbg);

}