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/*
* drivers/platform/tegra/pm_debugfs.c
*
* Copyright (c) 2017, NVIDIA CORPORATION. All rights reserved.
*
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* 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/debugfs.h>
#include <linux/tegra-pm.h>
/* Debugfs handle for /d/system_states directory */
static struct dentry *system_states_debugfs;
/* Suspend debug flags used in /d/system_states/suspend_debug_flags */
static u32 suspend_debug_flags;
/*
* Helper function for send_smc that actually makes the smc call
*/
static noinline notrace int __send_smc(u32 smc_func, struct pm_regs *regs)
{
u32 ret = smc_func;
asm volatile (
" mov x0, %0\n"
" ldp x1, x2, [%1, #16 * 0]\n"
" ldp x3, x4, [%1, #16 * 1]\n"
" ldp x5, x6, [%1, #16 * 2]\n"
" isb\n"
" smc #0\n"
" mov %0, x0\n"
" stp x0, x1, [%1, #16 * 0]\n"
" stp x2, x3, [%1, #16 * 1]\n"
: "+r" (ret)
: "r" (regs)
: "x0", "x1", "x2", "x3", "x4", "x5", "x6", "x7", "x8",
"x9", "x10", "x11", "x12", "x13", "x14", "x15", "x16", "x17");
return ret;
}
/*
* Make an SMC call. Takes in the SMC function to be invoked & registers to be
* passed along as args.
*/
int send_smc(u32 smc_func, struct pm_regs *regs)
{
int __ret = __send_smc(smc_func, regs);
if (__ret) {
pr_err("%s: failed (ret=%d)\n", __func__, __ret);
return __ret;
}
return __ret;
}
/*
* Specify debug flags for system suspend.
*/
static int tegra_set_suspend_debug_flags(u32 debug_flags)
{
struct pm_regs regs;
u32 smc_func = SMC_FAKE_SYS_SUSPEND |
(FAKE_SYSTEM_SUSPEND_MODE & SMC_ENUM_MAX);
regs.args[0] = debug_flags;
return send_smc(smc_func, ®s);
}
EXPORT_SYMBOL(tegra_set_suspend_debug_flags);
/*
* Get suspend debug flags. It is used by debugfs ops.
*/
static int suspend_debug_flags_get(void *data, u64 *val)
{
*val = suspend_debug_flags;
return 0;
}
/*
* Set suspend debug flags. It is used by debugfs ops.
*/
static int suspend_debug_flags_set(void *data, u64 val)
{
int ret;
if (val == FAKE_SYSTEM_SUSPEND_USER_ARG) {
suspend_debug_flags = FAKE_SYSTEM_SUSPEND_MODE;
ret = tegra_set_suspend_debug_flags(suspend_debug_flags);
} else {
pr_err("Invalid suspend debug flags\n");
ret = -1;
}
return ret;
}
DEFINE_SIMPLE_ATTRIBUTE(suspend_debug_flags_fops,
suspend_debug_flags_get, suspend_debug_flags_set, "%llu\n");
/*
* Interface that returns the debugfs handle for /d/system_states directory.
* In case its not initialized, it creates it.
*/
struct dentry *return_system_states_dir(void)
{
if (system_states_debugfs == NULL) {
system_states_debugfs =
debugfs_create_dir("system_states", NULL);
if (system_states_debugfs == NULL)
pr_err("Cannot create system_states debugfs dir\n");
}
return system_states_debugfs;
}
EXPORT_SYMBOL(return_system_states_dir);
static int __init fake_system_suspend_debugfs_init(void)
{
struct dentry *dfs_file = NULL;
struct dentry *debugfs_dir = return_system_states_dir();
if (!debugfs_dir) {
pr_err("/d/system_states was not created. Aborting\n");
return -ENOENT;
}
dfs_file = debugfs_create_file("suspend_debug_flags", 0644,
debugfs_dir, NULL, &suspend_debug_flags_fops);
if (!dfs_file) {
pr_err("Not able to create suspend_debug_flags debugfs node\n");
return -ENOENT;
}
return 0;
}
late_initcall(fake_system_suspend_debugfs_init);
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