// 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 __printf(3, 0) struct clk_lookup * __refvclkdev_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_obj(*cla);	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 __printf(3, 0) 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 __printf(3, 4) 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);