linux/drivers/clk/clkdev.c

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// 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>
clk: add DT clock binding support Based on work 1st by Ben Herrenschmidt and Jeremy Kerr, then by Grant Likely, this patch adds support to clk_get to allow drivers to retrieve clock data from the device tree. Platforms scan for clocks in DT with of_clk_init and a match table, and the register a provider through of_clk_add_provider. The provider's clk_src_get function will be called when a device references the provider's OF node for a clock reference. v6 (Rob Herring): - Return error values instead of NULL to match clock framework expectations v5 (Rob Herring): - Move from drivers/of into common clock subsystem - Squashed "dt/clock: add a simple provider get function" and "dt/clock: add function to get parent clock name" - Rebase to 3.4-rc1 - Drop CONFIG_OF_CLOCK and just use CONFIG_OF - Add missing EXPORT_SYMBOL to various functions - s/clock-output-name/clock-output-names/ - Define that fixed-clock binding is a single output v4 (Rob Herring): - Rework for common clk subsystem - Add of_clk_get_parent_name function v3: - Clarified documentation v2: - fixed errant ';' causing compile error - Editorial fixes from Shawn Guo - merged in adding lookup to clkdev - changed property names to match established convention. After working with the binding a bit it really made more sense to follow the lead of 'reg', 'gpios' and 'interrupts' by making the input simply 'clocks' & 'clock-names' instead of 'clock-input-*', and to only use clock-output* for the producer nodes. (Sorry Shawn, this will mean you need to change some code, but it should be trivial) - Add ability to inherit clocks from parent nodes by using an empty 'clock-ranges' property. Useful for busses. I could use some feedback on the new property name, 'clock-ranges' doesn't feel right to me. Signed-off-by: Grant Likely <grant.likely@secretlab.ca> Signed-off-by: Rob Herring <rob.herring@calxeda.com> Reviewed-by: Shawn Guo <shawn.guo@freescale.com> Cc: Sascha Hauer <kernel@pengutronix.de> Signed-off-by: Mike Turquette <mturquette@linaro.org>
2012-04-10 03:50:06 +08:00
#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;
clk: add DT clock binding support Based on work 1st by Ben Herrenschmidt and Jeremy Kerr, then by Grant Likely, this patch adds support to clk_get to allow drivers to retrieve clock data from the device tree. Platforms scan for clocks in DT with of_clk_init and a match table, and the register a provider through of_clk_add_provider. The provider's clk_src_get function will be called when a device references the provider's OF node for a clock reference. v6 (Rob Herring): - Return error values instead of NULL to match clock framework expectations v5 (Rob Herring): - Move from drivers/of into common clock subsystem - Squashed "dt/clock: add a simple provider get function" and "dt/clock: add function to get parent clock name" - Rebase to 3.4-rc1 - Drop CONFIG_OF_CLOCK and just use CONFIG_OF - Add missing EXPORT_SYMBOL to various functions - s/clock-output-name/clock-output-names/ - Define that fixed-clock binding is a single output v4 (Rob Herring): - Rework for common clk subsystem - Add of_clk_get_parent_name function v3: - Clarified documentation v2: - fixed errant ';' causing compile error - Editorial fixes from Shawn Guo - merged in adding lookup to clkdev - changed property names to match established convention. After working with the binding a bit it really made more sense to follow the lead of 'reg', 'gpios' and 'interrupts' by making the input simply 'clocks' & 'clock-names' instead of 'clock-input-*', and to only use clock-output* for the producer nodes. (Sorry Shawn, this will mean you need to change some code, but it should be trivial) - Add ability to inherit clocks from parent nodes by using an empty 'clock-ranges' property. Useful for busses. I could use some feedback on the new property name, 'clock-ranges' doesn't feel right to me. Signed-off-by: Grant Likely <grant.likely@secretlab.ca> Signed-off-by: Rob Herring <rob.herring@calxeda.com> Reviewed-by: Shawn Guo <shawn.guo@freescale.com> Cc: Sascha Hauer <kernel@pengutronix.de> Signed-off-by: Mike Turquette <mturquette@linaro.org>
2012-04-10 03:50:06 +08:00
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);
clk: add DT clock binding support Based on work 1st by Ben Herrenschmidt and Jeremy Kerr, then by Grant Likely, this patch adds support to clk_get to allow drivers to retrieve clock data from the device tree. Platforms scan for clocks in DT with of_clk_init and a match table, and the register a provider through of_clk_add_provider. The provider's clk_src_get function will be called when a device references the provider's OF node for a clock reference. v6 (Rob Herring): - Return error values instead of NULL to match clock framework expectations v5 (Rob Herring): - Move from drivers/of into common clock subsystem - Squashed "dt/clock: add a simple provider get function" and "dt/clock: add function to get parent clock name" - Rebase to 3.4-rc1 - Drop CONFIG_OF_CLOCK and just use CONFIG_OF - Add missing EXPORT_SYMBOL to various functions - s/clock-output-name/clock-output-names/ - Define that fixed-clock binding is a single output v4 (Rob Herring): - Rework for common clk subsystem - Add of_clk_get_parent_name function v3: - Clarified documentation v2: - fixed errant ';' causing compile error - Editorial fixes from Shawn Guo - merged in adding lookup to clkdev - changed property names to match established convention. After working with the binding a bit it really made more sense to follow the lead of 'reg', 'gpios' and 'interrupts' by making the input simply 'clocks' & 'clock-names' instead of 'clock-input-*', and to only use clock-output* for the producer nodes. (Sorry Shawn, this will mean you need to change some code, but it should be trivial) - Add ability to inherit clocks from parent nodes by using an empty 'clock-ranges' property. Useful for busses. I could use some feedback on the new property name, 'clock-ranges' doesn't feel right to me. Signed-off-by: Grant Likely <grant.likely@secretlab.ca> Signed-off-by: Rob Herring <rob.herring@calxeda.com> Reviewed-by: Shawn Guo <shawn.guo@freescale.com> Cc: Sascha Hauer <kernel@pengutronix.de> Signed-off-by: Mike Turquette <mturquette@linaro.org>
2012-04-10 03:50:06 +08:00
}
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 20
#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;
cla = kzalloc(sizeof(*cla), GFP_KERNEL);
if (!cla)
return NULL;
cla->cl.clk_hw = hw;
if (con_id) {
strlcpy(cla->con_id, con_id, sizeof(cla->con_id));
cla->cl.con_id = cla->con_id;
}
if (dev_fmt) {
vscnprintf(cla->dev_id, sizeof(cla->dev_id), dev_fmt, ap);
cla->cl.dev_id = 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;
}
struct clk_lookup * __ref
clkdev_alloc(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_alloc(__clk_get_hw(clk), con_id, dev_fmt, ap);
va_end(ap);
return cl;
}
EXPORT_SYMBOL(clkdev_alloc);
struct clk_lookup *
clkdev_hw_alloc(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_alloc(hw, con_id, dev_fmt, ap);
va_end(ap);
return cl;
}
EXPORT_SYMBOL(clkdev_hw_alloc);
/**
* 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(struct device *dev, void *res)
{
clkdev_drop(*(struct clk_lookup **)res);
}
static int devm_clk_match_clkdev(struct device *dev, void *res, void *data)
{
struct clk_lookup **l = res;
return *l == data;
}
/**
* devm_clk_release_clkdev - Resource managed clkdev lookup release
* @dev: device this lookup is bound
* @con_id: connection ID string on device
* @dev_id: format string describing device name
*
* Drop the clkdev lookup created with devm_clk_hw_register_clkdev.
* Normally this function will not need to be called and the resource
* management code will ensure that the resource is freed.
*/
void devm_clk_release_clkdev(struct device *dev, const char *con_id,
const char *dev_id)
{
struct clk_lookup *cl;
int rval;
mutex_lock(&clocks_mutex);
cl = clk_find(dev_id, con_id);
mutex_unlock(&clocks_mutex);
WARN_ON(!cl);
rval = devres_release(dev, devm_clkdev_release,
devm_clk_match_clkdev, cl);
WARN_ON(rval);
}
EXPORT_SYMBOL(devm_clk_release_clkdev);
/**
* 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)
{
int rval = -ENOMEM;
struct clk_lookup **cl;
cl = devres_alloc(devm_clkdev_release, sizeof(*cl), GFP_KERNEL);
if (cl) {
rval = do_clk_register_clkdev(hw, cl, con_id, dev_id);
if (!rval)
devres_add(dev, cl);
else
devres_free(cl);
}
return rval;
}
EXPORT_SYMBOL(devm_clk_hw_register_clkdev);