linux/arch/arm/mach-tegra/clock.c

167 lines
3.7 KiB
C

/*
*
* Copyright (C) 2010 Google, Inc.
* Copyright (c) 2012 NVIDIA CORPORATION. All rights reserved.
*
* Author:
* Colin Cross <ccross@google.com>
*
* 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/clk.h>
#include <linux/clkdev.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/seq_file.h>
#include <linux/slab.h>
#include "board.h"
#include "clock.h"
#include "tegra_cpu_car.h"
/* Global data of Tegra CPU CAR ops */
struct tegra_cpu_car_ops *tegra_cpu_car_ops;
/*
* Locking:
*
* An additional mutex, clock_list_lock, is used to protect the list of all
* clocks.
*
*/
static DEFINE_MUTEX(clock_list_lock);
static LIST_HEAD(clocks);
void tegra_clk_add(struct clk *clk)
{
struct clk_tegra *c = to_clk_tegra(__clk_get_hw(clk));
mutex_lock(&clock_list_lock);
list_add(&c->node, &clocks);
mutex_unlock(&clock_list_lock);
}
struct clk *tegra_get_clock_by_name(const char *name)
{
struct clk_tegra *c;
struct clk *ret = NULL;
mutex_lock(&clock_list_lock);
list_for_each_entry(c, &clocks, node) {
if (strcmp(__clk_get_name(c->hw.clk), name) == 0) {
ret = c->hw.clk;
break;
}
}
mutex_unlock(&clock_list_lock);
return ret;
}
static int tegra_clk_init_one_from_table(struct tegra_clk_init_table *table)
{
struct clk *c;
struct clk *p;
struct clk *parent;
int ret = 0;
c = tegra_get_clock_by_name(table->name);
if (!c) {
pr_warn("Unable to initialize clock %s\n",
table->name);
return -ENODEV;
}
parent = clk_get_parent(c);
if (table->parent) {
p = tegra_get_clock_by_name(table->parent);
if (!p) {
pr_warn("Unable to find parent %s of clock %s\n",
table->parent, table->name);
return -ENODEV;
}
if (parent != p) {
ret = clk_set_parent(c, p);
if (ret) {
pr_warn("Unable to set parent %s of clock %s: %d\n",
table->parent, table->name, ret);
return -EINVAL;
}
}
}
if (table->rate && table->rate != clk_get_rate(c)) {
ret = clk_set_rate(c, table->rate);
if (ret) {
pr_warn("Unable to set clock %s to rate %lu: %d\n",
table->name, table->rate, ret);
return -EINVAL;
}
}
if (table->enabled) {
ret = clk_prepare_enable(c);
if (ret) {
pr_warn("Unable to enable clock %s: %d\n",
table->name, ret);
return -EINVAL;
}
}
return 0;
}
void tegra_clk_init_from_table(struct tegra_clk_init_table *table)
{
for (; table->name; table++)
tegra_clk_init_one_from_table(table);
}
void tegra_periph_reset_deassert(struct clk *c)
{
struct clk_tegra *clk = to_clk_tegra(__clk_get_hw(c));
BUG_ON(!clk->reset);
clk->reset(__clk_get_hw(c), false);
}
EXPORT_SYMBOL(tegra_periph_reset_deassert);
void tegra_periph_reset_assert(struct clk *c)
{
struct clk_tegra *clk = to_clk_tegra(__clk_get_hw(c));
BUG_ON(!clk->reset);
clk->reset(__clk_get_hw(c), true);
}
EXPORT_SYMBOL(tegra_periph_reset_assert);
/* Several extended clock configuration bits (e.g., clock routing, clock
* phase control) are included in PLL and peripheral clock source
* registers. */
int tegra_clk_cfg_ex(struct clk *c, enum tegra_clk_ex_param p, u32 setting)
{
int ret = 0;
struct clk_tegra *clk = to_clk_tegra(__clk_get_hw(c));
if (!clk->clk_cfg_ex) {
ret = -ENOSYS;
goto out;
}
ret = clk->clk_cfg_ex(__clk_get_hw(c), p, setting);
out:
return ret;
}