- 根目录:
- drivers
- clk
- samsung
- clk.c
/*
* Copyright (c) 2013 Samsung Electronics Co., Ltd.
* Copyright (c) 2013 Linaro Ltd.
* Author: Thomas Abraham <thomas.ab@samsung.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 file includes utility functions to register clocks to common
* clock framework for Samsung platforms.
*/
#include <linux/slab.h>
#include <linux/clkdev.h>
#include <linux/clk.h>
#include <linux/clk-provider.h>
#include <linux/of_address.h>
#include <linux/syscore_ops.h>
#include "clk.h"
static LIST_HEAD(clock_reg_cache_list);
void samsung_clk_save(void __iomem *base,
struct samsung_clk_reg_dump *rd,
unsigned int num_regs)
{
for (; num_regs > 0; --num_regs, ++rd)
rd->value = readl(base + rd->offset);
}
void samsung_clk_restore(void __iomem *base,
const struct samsung_clk_reg_dump *rd,
unsigned int num_regs)
{
for (; num_regs > 0; --num_regs, ++rd)
writel(rd->value, base + rd->offset);
}
struct samsung_clk_reg_dump *samsung_clk_alloc_reg_dump(
const unsigned long *rdump,
unsigned long nr_rdump)
{
struct samsung_clk_reg_dump *rd;
unsigned int i;
rd = kcalloc(nr_rdump, sizeof(*rd), GFP_KERNEL);
if (!rd)
return NULL;
for (i = 0; i < nr_rdump; ++i)
rd[i].offset = rdump[i];
return rd;
}
/* setup the essentials required to support clock lookup using ccf */
struct samsung_clk_provider *__init samsung_clk_init(struct device_node *np,
void __iomem *base, unsigned long nr_clks)
{
struct samsung_clk_provider *ctx;
struct clk **clk_table;
int i;
ctx = kzalloc(sizeof(struct samsung_clk_provider), GFP_KERNEL);
if (!ctx)
panic("could not allocate clock provider context.\n");
clk_table = kcalloc(nr_clks, sizeof(struct clk *), GFP_KERNEL);
if (!clk_table)
panic("could not allocate clock lookup table\n");
for (i = 0; i < nr_clks; ++i)
clk_table[i] = ERR_PTR(-ENOENT);
ctx->reg_base = base;
ctx->clk_data.clks = clk_table;
ctx->clk_data.clk_num = nr_clks;
spin_lock_init(&ctx->lock);
return ctx;
}
void __init samsung_clk_of_add_provider(struct device_node *np,
struct samsung_clk_provider *ctx)
{
if (np) {
if (of_clk_add_provider(np, of_clk_src_onecell_get,
&ctx->clk_data))
panic("could not register clk provider\n");
}
}
/* add a clock instance to the clock lookup table used for dt based lookup */
void samsung_clk_add_lookup(struct samsung_clk_provider *ctx, struct clk *clk,
unsigned int id)
{
if (ctx->clk_data.clks && id)
ctx->clk_data.clks[id] = clk;
}
/* register a list of aliases */
void __init samsung_clk_register_alias(struct samsung_clk_provider *ctx,
const struct samsung_clock_alias *list,
unsigned int nr_clk)
{
struct clk *clk;
unsigned int idx, ret;
if (!ctx->clk_data.clks) {
pr_err("%s: clock table missing\n", __func__);
return;
}
for (idx = 0; idx < nr_clk; idx++, list++) {
if (!list->id) {
pr_err("%s: clock id missing for index %d\n", __func__,
idx);
continue;
}
clk = ctx->clk_data.clks[list->id];
if (!clk) {
pr_err("%s: failed to find clock %d\n", __func__,
list->id);
continue;
}
ret = clk_register_clkdev(clk, list->alias, list->dev_name);
if (ret)
pr_err("%s: failed to register lookup %s\n",
__func__, list->alias);
}
}
/* register a list of fixed clocks */
void __init samsung_clk_register_fixed_rate(struct samsung_clk_provider *ctx,
const struct samsung_fixed_rate_clock *list,
unsigned int nr_clk)
{
struct clk *clk;
unsigned int idx, ret;
for (idx = 0; idx < nr_clk; idx++, list++) {
clk = clk_register_fixed_rate(NULL, list->name,
list->parent_name, list->flags, list->fixed_rate);
if (IS_ERR(clk)) {
pr_err("%s: failed to register clock %s\n", __func__,
list->name);
continue;
}
samsung_clk_add_lookup(ctx, clk, list->id);
/*
* Unconditionally add a clock lookup for the fixed rate clocks.
* There are not many of these on any of Samsung platforms.
*/
ret = clk_register_clkdev(clk, list->name, NULL);
if (ret)
pr_err("%s: failed to register clock lookup for %s",
__func__, list->name);
}
}
/* register a list of fixed factor clocks */
void __init samsung_clk_register_fixed_factor(struct samsung_clk_provider *ctx,
const struct samsung_fixed_factor_clock *list, unsigned int nr_clk)
{
struct clk *clk;
unsigned int idx;
for (idx = 0; idx < nr_clk; idx++, list++) {
clk = clk_register_fixed_factor(NULL, list->name,
list->parent_name, list->flags, list->mult, list->div);
if (IS_ERR(clk)) {
pr_err("%s: failed to register clock %s\n", __func__,
list->name);
continue;
}
samsung_clk_add_lookup(ctx, clk, list->id);
}
}
/* register a list of mux clocks */
void __init samsung_clk_register_mux(struct samsung_clk_provider *ctx,
const struct samsung_mux_clock *list,
unsigned int nr_clk)
{
struct clk *clk;
unsigned int idx, ret;
for (idx = 0; idx < nr_clk; idx++, list++) {
clk = clk_register_mux(NULL, list->name, list->parent_names,
list->num_parents, list->flags,
ctx->reg_base + list->offset,
list->shift, list->width, list->mux_flags, &ctx->lock);
if (IS_ERR(clk)) {
pr_err("%s: failed to register clock %s\n", __func__,
list->name);
continue;
}
samsung_clk_add_lookup(ctx, clk, list->id);
/* register a clock lookup only if a clock alias is specified */
if (list->alias) {
ret = clk_register_clkdev(clk, list->alias,
list->dev_name);
if (ret)
pr_err("%s: failed to register lookup %s\n",
__func__, list->alias);
}
}
}
/* register a list of div clocks */
void __init samsung_clk_register_div(struct samsung_clk_provider *ctx,
const struct samsung_div_clock *list,
unsigned int nr_clk)
{
struct clk *clk;
unsigned int idx, ret;
for (idx = 0; idx < nr_clk; idx++, list++) {
if (list->table)
clk = clk_register_divider_table(NULL, list->name,
list->parent_name, list->flags,
ctx->reg_base + list->offset,
list->shift, list->width, list->div_flags,
list->table, &ctx->lock);
else
clk = clk_register_divider(NULL, list->name,
list->parent_name, list->flags,
ctx->reg_base + list->offset, list->shift,
list->width, list->div_flags, &ctx->lock);
if (IS_ERR(clk)) {
pr_err("%s: failed to register clock %s\n", __func__,
list->name);
continue;
}
samsung_clk_add_lookup(ctx, clk, list->id);
/* register a clock lookup only if a clock alias is specified */
if (list->alias) {
ret = clk_register_clkdev(clk, list->alias,
list->dev_name);
if (ret)
pr_err("%s: failed to register lookup %s\n",
__func__, list->alias);
}
}
}
/* register a list of gate clocks */
void __init samsung_clk_register_gate(struct samsung_clk_provider *ctx,
const struct samsung_gate_clock *list,
unsigned int nr_clk)
{
struct clk *clk;
unsigned int idx, ret;
for (idx = 0; idx < nr_clk; idx++, list++) {
clk = clk_register_gate(NULL, list->name, list->parent_name,
list->flags, ctx->reg_base + list->offset,
list->bit_idx, list->gate_flags, &ctx->lock);
if (IS_ERR(clk)) {
pr_err("%s: failed to register clock %s\n", __func__,
list->name);
continue;
}
/* register a clock lookup only if a clock alias is specified */
if (list->alias) {
ret = clk_register_clkdev(clk, list->alias,
list->dev_name);
if (ret)
pr_err("%s: failed to register lookup %s\n",
__func__, list->alias);
}
samsung_clk_add_lookup(ctx, clk, list->id);
}
}
/*
* obtain the clock speed of all external fixed clock sources from device
* tree and register it
*/
void __init samsung_clk_of_register_fixed_ext(struct samsung_clk_provider *ctx,
struct samsung_fixed_rate_clock *fixed_rate_clk,
unsigned int nr_fixed_rate_clk,
const struct of_device_id *clk_matches)
{
const struct of_device_id *match;
struct device_node *clk_np;
u32 freq;
for_each_matching_node_and_match(clk_np, clk_matches, &match) {
if (of_property_read_u32(clk_np, "clock-frequency", &freq))
continue;
fixed_rate_clk[(unsigned long)match->data].fixed_rate = freq;
}
samsung_clk_register_fixed_rate(ctx, fixed_rate_clk, nr_fixed_rate_clk);
}
/* utility function to get the rate of a specified clock */
unsigned long _get_rate(const char *clk_name)
{
struct clk *clk;
clk = __clk_lookup(clk_name);
if (!clk) {
pr_err("%s: could not find clock %s\n", __func__, clk_name);
return 0;
}
return clk_get_rate(clk);
}
#ifdef CONFIG_PM_SLEEP
static int samsung_clk_suspend(void)
{
struct samsung_clock_reg_cache *reg_cache;
list_for_each_entry(reg_cache, &clock_reg_cache_list, node)
samsung_clk_save(reg_cache->reg_base, reg_cache->rdump,
reg_cache->rd_num);
return 0;
}
static void samsung_clk_resume(void)
{
struct samsung_clock_reg_cache *reg_cache;
list_for_each_entry(reg_cache, &clock_reg_cache_list, node)
samsung_clk_restore(reg_cache->reg_base, reg_cache->rdump,
reg_cache->rd_num);
}
static struct syscore_ops samsung_clk_syscore_ops = {
.suspend = samsung_clk_suspend,
.resume = samsung_clk_resume,
};
static void samsung_clk_sleep_init(void __iomem *reg_base,
const unsigned long *rdump,
unsigned long nr_rdump)
{
struct samsung_clock_reg_cache *reg_cache;
reg_cache = kzalloc(sizeof(struct samsung_clock_reg_cache),
GFP_KERNEL);
if (!reg_cache)
panic("could not allocate register reg_cache.\n");
reg_cache->rdump = samsung_clk_alloc_reg_dump(rdump, nr_rdump);
if (!reg_cache->rdump)
panic("could not allocate register dump storage.\n");
if (list_empty(&clock_reg_cache_list))
register_syscore_ops(&samsung_clk_syscore_ops);
reg_cache->reg_base = reg_base;
reg_cache->rd_num = nr_rdump;
list_add_tail(®_cache->node, &clock_reg_cache_list);
}
#else
static void samsung_clk_sleep_init(void __iomem *reg_base,
const unsigned long *rdump,
unsigned long nr_rdump) {}
#endif
/*
* Common function which registers plls, muxes, dividers and gates
* for each CMU. It also add CMU register list to register cache.
*/
struct samsung_clk_provider * __init samsung_cmu_register_one(
struct device_node *np,
struct samsung_cmu_info *cmu)
{
void __iomem *reg_base;
struct samsung_clk_provider *ctx;
reg_base = of_iomap(np, 0);
if (!reg_base) {
panic("%s: failed to map registers\n", __func__);
return NULL;
}
ctx = samsung_clk_init(np, reg_base, cmu->nr_clk_ids);
if (!ctx) {
panic("%s: unable to allocate ctx\n", __func__);
return ctx;
}
if (cmu->pll_clks)
samsung_clk_register_pll(ctx, cmu->pll_clks, cmu->nr_pll_clks,
reg_base);
if (cmu->mux_clks)
samsung_clk_register_mux(ctx, cmu->mux_clks,
cmu->nr_mux_clks);
if (cmu->div_clks)
samsung_clk_register_div(ctx, cmu->div_clks, cmu->nr_div_clks);
if (cmu->gate_clks)
samsung_clk_register_gate(ctx, cmu->gate_clks,
cmu->nr_gate_clks);
if (cmu->fixed_clks)
samsung_clk_register_fixed_rate(ctx, cmu->fixed_clks,
cmu->nr_fixed_clks);
if (cmu->fixed_factor_clks)
samsung_clk_register_fixed_factor(ctx, cmu->fixed_factor_clks,
cmu->nr_fixed_factor_clks);
if (cmu->clk_regs)
samsung_clk_sleep_init(reg_base, cmu->clk_regs,
cmu->nr_clk_regs);
samsung_clk_of_add_provider(np, ctx);
return ctx;
}