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// SPDX-License-Identifier: GPL-2.0
/*
* GXP wakelock support
*
* Copyright (C) 2022 Google LLC
*/
#include "gxp-client.h"
#include "gxp-dma.h"
#include "gxp-pm.h"
#include "gxp-wakelock.h"
int gxp_wakelock_init(struct gxp_dev *gxp)
{
struct gxp_wakelock_manager *mgr;
mgr = devm_kzalloc(gxp->dev, sizeof(*mgr), GFP_KERNEL);
if (!mgr)
return -ENOMEM;
mutex_init(&mgr->lock);
gxp->wakelock_mgr = mgr;
return 0;
}
int gxp_wakelock_acquire(struct gxp_dev *gxp)
{
struct gxp_wakelock_manager *mgr = gxp->wakelock_mgr;
int ret = 0;
mutex_lock(&mgr->lock);
if (mgr->suspended) {
/*
* Don't allow a new client to obtain a wakelock, powering up
* BLK_AUR, when the system is going to sleep.
*/
dev_warn(gxp->dev,
"Attempt to obtain wakelock while suspending.\n");
ret = -EAGAIN;
goto out;
}
if (!mgr->count++) {
ret = gxp_pm_blk_on(gxp);
if (ret) {
dev_err(gxp->dev,
"Failed to power on BLK_AUR (ret=%d, client count=%u)\n",
ret, mgr->count);
goto err_blk_on;
}
}
out:
mutex_unlock(&mgr->lock);
return ret;
err_blk_on:
mgr->count--;
mutex_unlock(&mgr->lock);
return ret;
}
void gxp_wakelock_release(struct gxp_dev *gxp)
{
struct gxp_wakelock_manager *mgr = gxp->wakelock_mgr;
int ret = 0;
mutex_lock(&mgr->lock);
if (!mgr->count) {
dev_err(gxp->dev,
"Attempt to release wakelock with none held.\n");
goto out;
}
if (!--mgr->count) {
ret = gxp_pm_blk_off(gxp);
if (ret)
dev_err(gxp->dev,
"Failed to power down BLK_AUR (ret=%d, client count=%u)\n",
ret, mgr->count);
}
out:
mutex_unlock(&mgr->lock);
}
int gxp_wakelock_suspend(struct gxp_dev *gxp)
{
struct gxp_wakelock_manager *mgr = gxp->wakelock_mgr;
int ret;
struct gxp_client *client;
if (!mutex_trylock(&mgr->lock))
return -EAGAIN;
/* Can't suspend if there are any active clients */
mgr->suspended = mgr->count == 0;
ret = mgr->suspended ? 0 : -EAGAIN;
/* Suspend successful. Can exit now. */
if (!ret)
goto out;
/* Log clients currently holding a wakelock */
if (!mutex_trylock(&gxp->client_list_lock)) {
dev_warn_ratelimited(
gxp->dev,
"Unable to get client list lock on suspend failure\n");
goto out;
}
list_for_each_entry(client, &gxp->client_list, list_entry) {
if (!down_read_trylock(&client->semaphore)) {
dev_warn_ratelimited(
gxp->dev,
"Unable to acquire client lock (tgid=%d pid=%d)\n",
client->tgid, client->pid);
continue;
}
if (client->has_block_wakelock)
dev_warn_ratelimited(
gxp->dev,
"Cannot suspend with client holding wakelock (tgid=%d pid=%d)\n",
client->tgid, client->pid);
up_read(&client->semaphore);
}
mutex_unlock(&gxp->client_list_lock);
out:
mutex_unlock(&mgr->lock);
return ret;
}
int gxp_wakelock_resume(struct gxp_dev *gxp)
{
struct gxp_wakelock_manager *mgr = gxp->wakelock_mgr;
mutex_lock(&mgr->lock);
mgr->suspended = false;
mutex_unlock(&mgr->lock);
return 0;
}
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