// SPDX-License-Identifier: GPL-2.0-only
/*
* drivers/clk/clkdev.c
*
* Copyright (C) 2008 Russell King.
*
* Helper for the clk API to assist looking up a struct clk.
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/list.h>
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/string.h>
#include <linux/mutex.h>
#include <linux/clk.h>
#include <linux/clkdev.h>
#include <linux/clk-provider.h>
#include <linux/of.h>
#include "clk.h"
static LIST_HEAD(clocks);
static DEFINE_MUTEX(clocks_mutex);
/*
* Find the correct struct clk for the device and connection ID.
* We do slightly fuzzy matching here:
* An entry with a NULL ID is assumed to be a wildcard.
* If an entry has a device ID, it must match
* If an entry has a connection ID, it must match
* Then we take the most specific entry - with the following
* order of precedence: dev+con > dev only > con only.
*/
static struct clk_lookup *clk_find(const char *dev_id, const char *con_id)
{
struct clk_lookup *p, *cl = NULL;
int match, best_found = 0, best_possible = 0;
if (dev_id)
best_possible += 2;
if (con_id)
best_possible += 1;
lockdep_assert_held(&clocks_mutex);
list_for_each_entry(p, &clocks, node) {
match = 0;
if (p->dev_id) {
if (!dev_id || strcmp(p->dev_id, dev_id))
continue;
match += 2;
}
if (p->con_id) {
if (!con_id || strcmp(p->con_id, con_id))
continue;
match += 1;
}
if (match > best_found) {
cl = p;
if (match != best_possible)
best_found = match;
else
break;
}
}
return cl;
}
struct clk_hw *clk_find_hw(const char *dev_id, const char *con_id)
{
struct clk_lookup *cl;
struct clk_hw *hw = ERR_PTR(-ENOENT);
mutex_lock(&clocks_mutex);
cl = clk_find(dev_id, con_id);
if (cl)
hw = cl->clk_hw;
mutex_unlock(&clocks_mutex);
return hw;
}
static struct clk *__clk_get_sys(struct device *dev, const char *dev_id,
const char *con_id)
{
struct clk_hw *hw = clk_find_hw(dev_id, con_id);
return clk_hw_create_clk(dev, hw, dev_id, con_id);
}
struct clk *clk_get_sys(const char *dev_id, const char *con_id)
{
return __clk_get_sys(NULL, dev_id, con_id);
}
EXPORT_SYMBOL(clk_get_sys);
struct clk *clk_get(struct device *dev, const char *con_id)
{
const char *dev_id = dev ? dev_name(dev) : NULL;
struct clk_hw *hw;
if (dev && dev->of_node) {
hw = of_clk_get_hw(dev->of_node, 0, con_id);
if (!IS_ERR(hw) || PTR_ERR(hw) == -EPROBE_DEFER)
return clk_hw_create_clk(dev, hw, dev_id, con_id);
}
return __clk_get_sys(dev, dev_id, con_id);
}
EXPORT_SYMBOL(clk_get);
void clk_put(struct clk *clk)
{
__clk_put(clk);
}
EXPORT_SYMBOL(clk_put);
static void __clkdev_add(struct clk_lookup *cl)
{
mutex_lock(&clocks_mutex);
list_add_tail(&cl->node, &clocks);
mutex_unlock(&clocks_mutex);
}
void clkdev_add(struct clk_lookup *cl)
{
if (!cl->clk_hw)
cl->clk_hw = __clk_get_hw(cl->clk);
__clkdev_add(cl);
}
EXPORT_SYMBOL(clkdev_add);
void clkdev_add_table(struct clk_lookup *cl, size_t num)
{
mutex_lock(&clocks_mutex);
while (num--) {
cl->clk_hw = __clk_get_hw(cl->clk);
list_add_tail(&cl->node, &clocks);
cl++;
}
mutex_unlock(&clocks_mutex);
}
#define MAX_DEV_ID 24
#define MAX_CON_ID 16
struct clk_lookup_alloc {
struct clk_lookup cl;
char dev_id[MAX_DEV_ID];
char con_id[MAX_CON_ID];
};
static struct clk_lookup * __ref
vclkdev_alloc(struct clk_hw *hw, const char *con_id, const char *dev_fmt,
va_list ap)
{
struct clk_lookup_alloc *cla;
struct va_format vaf;
const char *failure;
va_list ap_copy;
size_t max_size;
ssize_t res;
cla = kzalloc(sizeof(*cla), GFP_KERNEL);
if (!cla)
return NULL;
va_copy(ap_copy, ap);
cla->cl.clk_hw = hw;
if (con_id) {
res = strscpy(cla->con_id, con_id, sizeof(cla->con_id));
if (res < 0) {
max_size = sizeof(cla->con_id);
failure = "connection";
goto fail;
}
cla->cl.con_id = cla->con_id;
}
if (dev_fmt) {
res = vsnprintf(cla->dev_id, sizeof(cla->dev_id), dev_fmt, ap);
if (res >= sizeof(cla->dev_id)) {
max_size = sizeof(cla->dev_id);
failure = "device";
goto fail;
}
cla->cl.dev_id = cla->dev_id;
}
va_end(ap_copy);
return &cla->cl;
fail:
if (dev_fmt)
vaf.fmt = dev_fmt;
else
vaf.fmt = "null-device";
vaf.va = &ap_copy;
pr_err("%pV:%s: %s ID is greater than %zu\n",
&vaf, con_id, failure, max_size);
va_end(ap_copy);
/*
* Don't fail in this case, but as the entry won't ever match just
* fill it with something that also won't match.
*/
strscpy(cla->con_id, "bad", sizeof(cla->con_id));
strscpy(cla->dev_id, "bad", sizeof(cla->dev_id));
return &cla->cl;
}
static struct clk_lookup *
vclkdev_create(struct clk_hw *hw, const char *con_id, const char *dev_fmt,
va_list ap)
{
struct clk_lookup *cl;
cl = vclkdev_alloc(hw, con_id, dev_fmt, ap);
if (cl)
__clkdev_add(cl);
return cl;
}
/**
* clkdev_create - allocate and add a clkdev lookup structure
* @clk: struct clk to associate with all clk_lookups
* @con_id: connection ID string on device
* @dev_fmt: format string describing device name
*
* Returns a clk_lookup structure, which can be later unregistered and
* freed.
*/
struct clk_lookup *clkdev_create(struct clk *clk, const char *con_id,
const char *dev_fmt, ...)
{
struct clk_lookup *cl;
va_list ap;
va_start(ap, dev_fmt);
cl = vclkdev_create(__clk_get_hw(clk), con_id, dev_fmt, ap);
va_end(ap);
return cl;
}
EXPORT_SYMBOL_GPL(clkdev_create);
/**
* clkdev_hw_create - allocate and add a clkdev lookup structure
* @hw: struct clk_hw to associate with all clk_lookups
* @con_id: connection ID string on device
* @dev_fmt: format string describing device name
*
* Returns a clk_lookup structure, which can be later unregistered and
* freed.
*/
struct clk_lookup *clkdev_hw_create(struct clk_hw *hw, const char *con_id,
const char *dev_fmt, ...)
{
struct clk_lookup *cl;
va_list ap;
va_start(ap, dev_fmt);
cl = vclkdev_create(hw, con_id, dev_fmt, ap);
va_end(ap);
return cl;
}
EXPORT_SYMBOL_GPL(clkdev_hw_create);
int clk_add_alias(const char *alias, const char *alias_dev_name,
const char *con_id, struct device *dev)
{
struct clk *r = clk_get(dev, con_id);
struct clk_lookup *l;
if (IS_ERR(r))
return PTR_ERR(r);
l = clkdev_create(r, alias, alias_dev_name ? "%s" : NULL,
alias_dev_name);
clk_put(r);
return l ? 0 : -ENODEV;
}
EXPORT_SYMBOL(clk_add_alias);
/*
* clkdev_drop - remove a clock dynamically allocated
*/
void clkdev_drop(struct clk_lookup *cl)
{
mutex_lock(&clocks_mutex);
list_del(&cl->node);
mutex_unlock(&clocks_mutex);
kfree(cl);
}
EXPORT_SYMBOL(clkdev_drop);
static struct clk_lookup *__clk_register_clkdev(struct clk_hw *hw,
const char *con_id,
const char *dev_id, ...)
{
struct clk_lookup *cl;
va_list ap;
va_start(ap, dev_id);
cl = vclkdev_create(hw, con_id, dev_id, ap);
va_end(ap);
return cl;
}
static int do_clk_register_clkdev(struct clk_hw *hw,
struct clk_lookup **cl, const char *con_id, const char *dev_id)
{
if (IS_ERR(hw))
return PTR_ERR(hw);
/*
* Since dev_id can be NULL, and NULL is handled specially, we must
* pass it as either a NULL format string, or with "%s".
*/
if (dev_id)
*cl = __clk_register_clkdev(hw, con_id, "%s", dev_id);
else
*cl = __clk_register_clkdev(hw, con_id, NULL);
return *cl ? 0 : -ENOMEM;
}
/**
* clk_register_clkdev - register one clock lookup for a struct clk
* @clk: struct clk to associate with all clk_lookups
* @con_id: connection ID string on device
* @dev_id: string describing device name
*
* con_id or dev_id may be NULL as a wildcard, just as in the rest of
* clkdev.
*
* To make things easier for mass registration, we detect error clks
* from a previous clk_register() call, and return the error code for
* those. This is to permit this function to be called immediately
* after clk_register().
*/
int clk_register_clkdev(struct clk *clk, const char *con_id,
const char *dev_id)
{
struct clk_lookup *cl;
if (IS_ERR(clk))
return PTR_ERR(clk);
return do_clk_register_clkdev(__clk_get_hw(clk), &cl, con_id,
dev_id);
}
EXPORT_SYMBOL(clk_register_clkdev);
/**
* clk_hw_register_clkdev - register one clock lookup for a struct clk_hw
* @hw: struct clk_hw to associate with all clk_lookups
* @con_id: connection ID string on device
* @dev_id: format string describing device name
*
* con_id or dev_id may be NULL as a wildcard, just as in the rest of
* clkdev.
*
* To make things easier for mass registration, we detect error clk_hws
* from a previous clk_hw_register_*() call, and return the error code for
* those. This is to permit this function to be called immediately
* after clk_hw_register_*().
*/
int clk_hw_register_clkdev(struct clk_hw *hw, const char *con_id,
const char *dev_id)
{
struct clk_lookup *cl;
return do_clk_register_clkdev(hw, &cl, con_id, dev_id);
}
EXPORT_SYMBOL(clk_hw_register_clkdev);
static void devm_clkdev_release(void *res)
{
clkdev_drop(res);
}
/**
* devm_clk_hw_register_clkdev - managed clk lookup registration for clk_hw
* @dev: device this lookup is bound
* @hw: struct clk_hw to associate with all clk_lookups
* @con_id: connection ID string on device
* @dev_id: format string describing device name
*
* con_id or dev_id may be NULL as a wildcard, just as in the rest of
* clkdev.
*
* To make things easier for mass registration, we detect error clk_hws
* from a previous clk_hw_register_*() call, and return the error code for
* those. This is to permit this function to be called immediately
* after clk_hw_register_*().
*/
int devm_clk_hw_register_clkdev(struct device *dev, struct clk_hw *hw,
const char *con_id, const char *dev_id)
{
struct clk_lookup *cl;
int rval;
rval = do_clk_register_clkdev(hw, &cl, con_id, dev_id);
if (rval)
return rval;
return devm_add_action_or_reset(dev, devm_clkdev_release, cl);
}
EXPORT_SYMBOL(devm_clk_hw_register_clkdev);
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