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/*
* drivers/video/tegra/host/nvhost_acm.c
*
* Tegra Graphics Host Automatic Clock Management
*
* Copyright (c) 2010, NVIDIA Corporation.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* 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.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#include "nvhost_acm.h"
#include <linux/string.h>
#include <linux/sched.h>
#include <linux/err.h>
#include <linux/device.h>
#define ACM_TIMEOUT_MSEC 25
void nvhost_module_busy(struct nvhost_module *mod)
{
mutex_lock(&mod->lock);
cancel_delayed_work(&mod->powerdown);
if ((atomic_inc_return(&mod->refcount) == 1) && !mod->powered) {
int i;
if (mod->parent)
nvhost_module_busy(mod->parent);
for (i = 0; i < mod->num_clks; i++)
clk_enable(mod->clk[i]);
if (mod->func)
mod->func(mod, NVHOST_POWER_ACTION_ON);
mod->powered = true;
}
mutex_unlock(&mod->lock);
}
static void powerdown_handler(struct work_struct *work)
{
struct nvhost_module *mod;
mod = container_of(to_delayed_work(work), struct nvhost_module, powerdown);
mutex_lock(&mod->lock);
if ((atomic_read(&mod->refcount) == 0) && mod->powered){
int i;
if (mod->func)
mod->func(mod, NVHOST_POWER_ACTION_OFF);
for (i = 0; i < mod->num_clks; i++)
clk_disable(mod->clk[i]);
mod->powered = false;
if (mod->parent)
nvhost_module_idle(mod->parent);
}
mutex_unlock(&mod->lock);
}
void nvhost_module_idle_mult(struct nvhost_module *mod, int refs)
{
bool kick = false;
mutex_lock(&mod->lock);
if (atomic_sub_return(refs, &mod->refcount) == 0) {
BUG_ON(!mod->powered);
schedule_delayed_work(
&mod->powerdown, msecs_to_jiffies(ACM_TIMEOUT_MSEC));
kick = true;
}
mutex_unlock(&mod->lock);
if (kick)
wake_up(&mod->idle);
}
static const char *get_module_clk_id(const char *module, int index)
{
if (index == 1 && strcmp(module, "gr2d") == 0)
return "epp";
else if (index == 0)
return module;
return NULL;
}
int nvhost_module_init(struct nvhost_module *mod, const char *name,
nvhost_modulef func, struct nvhost_module *parent,
struct device *dev)
{
int i = 0;
mod->name = name;
while (i < NVHOST_MODULE_MAX_CLOCKS) {
long rate;
mod->clk[i] = clk_get(dev, get_module_clk_id(name, i));
if (IS_ERR_OR_NULL(mod->clk[i]))
break;
rate = clk_round_rate(mod->clk[i], UINT_MAX);
if (rate < 0) {
pr_err("%s: can't get maximum rate for %s\n",
__func__, name);
break;
}
clk_set_rate(mod->clk[i], rate);
i++;
}
mod->num_clks = i;
mod->func = func;
mod->parent = parent;
mod->powered = false;
mutex_init(&mod->lock);
init_waitqueue_head(&mod->idle);
INIT_DELAYED_WORK(&mod->powerdown, powerdown_handler);
return 0;
}
static int is_module_idle(struct nvhost_module *mod)
{
int count;
mutex_lock(&mod->lock);
count = atomic_read(&mod->refcount);
mutex_unlock(&mod->lock);
return (count == 0);
}
void nvhost_module_suspend(struct nvhost_module *mod)
{
wait_event(mod->idle, is_module_idle(mod));
flush_delayed_work(&mod->powerdown);
BUG_ON(mod->powered);
}
void nvhost_module_deinit(struct nvhost_module *mod)
{
int i;
nvhost_module_suspend(mod);
for (i = 0; i < mod->num_clks; i++)
clk_put(mod->clk[i]);
}
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