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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * drivers/clk/clkdev.c4 *5 * Copyright (C) 2008 Russell King.6 *7 * Helper for the clk API to assist looking up a struct clk.8 */9#include <linux/module.h>10#include <linux/kernel.h>11#include <linux/device.h>12#include <linux/list.h>13#include <linux/errno.h>14#include <linux/err.h>15#include <linux/string.h>16#include <linux/mutex.h>17#include <linux/clk.h>18#include <linux/clkdev.h>19#include <linux/clk-provider.h>20#include <linux/of.h>21 22#include "clk.h"23 24static LIST_HEAD(clocks);25static DEFINE_MUTEX(clocks_mutex);26 27/*28 * Find the correct struct clk for the device and connection ID.29 * We do slightly fuzzy matching here:30 * An entry with a NULL ID is assumed to be a wildcard.31 * If an entry has a device ID, it must match32 * If an entry has a connection ID, it must match33 * Then we take the most specific entry - with the following34 * order of precedence: dev+con > dev only > con only.35 */36static struct clk_lookup *clk_find(const char *dev_id, const char *con_id)37{38 struct clk_lookup *p, *cl = NULL;39 int match, best_found = 0, best_possible = 0;40 41 if (dev_id)42 best_possible += 2;43 if (con_id)44 best_possible += 1;45 46 lockdep_assert_held(&clocks_mutex);47 48 list_for_each_entry(p, &clocks, node) {49 match = 0;50 if (p->dev_id) {51 if (!dev_id || strcmp(p->dev_id, dev_id))52 continue;53 match += 2;54 }55 if (p->con_id) {56 if (!con_id || strcmp(p->con_id, con_id))57 continue;58 match += 1;59 }60 61 if (match > best_found) {62 cl = p;63 if (match != best_possible)64 best_found = match;65 else66 break;67 }68 }69 return cl;70}71 72struct clk_hw *clk_find_hw(const char *dev_id, const char *con_id)73{74 struct clk_lookup *cl;75 struct clk_hw *hw = ERR_PTR(-ENOENT);76 77 mutex_lock(&clocks_mutex);78 cl = clk_find(dev_id, con_id);79 if (cl)80 hw = cl->clk_hw;81 mutex_unlock(&clocks_mutex);82 83 return hw;84}85 86static HWJS_SUSPENDS struct clk *__clk_get_sys(struct device *dev, const char *dev_id,87 const char *con_id)88{89 struct clk_hw *hw = clk_find_hw(dev_id, con_id);90 91 return clk_hw_create_clk(dev, hw, dev_id, con_id);92}93 94struct clk *clk_get_sys(const char *dev_id, const char *con_id)95{96 return __clk_get_sys(NULL, dev_id, con_id);97}98EXPORT_SYMBOL(clk_get_sys);99 100struct clk *clk_get(struct device *dev, const char *con_id)101{102 const char *dev_id = dev ? dev_name(dev) : NULL;103 struct clk_hw *hw;104 105 if (dev && dev->of_node) {106 hw = of_clk_get_hw(dev->of_node, 0, con_id);107 if (!IS_ERR(hw) || PTR_ERR(hw) == -EPROBE_DEFER)108 return clk_hw_create_clk(dev, hw, dev_id, con_id);109 }110 111 return __clk_get_sys(dev, dev_id, con_id);112}113EXPORT_SYMBOL(clk_get);114 115void clk_put(struct clk *clk)116{117 __clk_put(clk);118}119EXPORT_SYMBOL(clk_put);120 121static HWJS_SUSPENDS void __clkdev_add(struct clk_lookup *cl)122{123 mutex_lock(&clocks_mutex);124 list_add_tail(&cl->node, &clocks);125 mutex_unlock(&clocks_mutex);126}127 128void clkdev_add(struct clk_lookup *cl)129{130 if (!cl->clk_hw)131 cl->clk_hw = __clk_get_hw(cl->clk);132 __clkdev_add(cl);133}134EXPORT_SYMBOL(clkdev_add);135 136void clkdev_add_table(struct clk_lookup *cl, size_t num)137{138 mutex_lock(&clocks_mutex);139 while (num--) {140 cl->clk_hw = __clk_get_hw(cl->clk);141 list_add_tail(&cl->node, &clocks);142 cl++;143 }144 mutex_unlock(&clocks_mutex);145}146 147#define MAX_DEV_ID 24148#define MAX_CON_ID 16149 150struct clk_lookup_alloc {151 struct clk_lookup cl;152 char dev_id[MAX_DEV_ID];153 char con_id[MAX_CON_ID];154};155 156static struct clk_lookup * __ref157vclkdev_alloc(struct clk_hw *hw, const char *con_id, const char *dev_fmt,158 va_list ap)159{160 struct clk_lookup_alloc *cla;161 struct va_format vaf;162 const char *failure;163 va_list ap_copy;164 size_t max_size;165 ssize_t res;166 167 cla = kzalloc(sizeof(*cla), GFP_KERNEL);168 if (!cla)169 return NULL;170 171 va_copy(ap_copy, ap);172 173 cla->cl.clk_hw = hw;174 if (con_id) {175 res = strscpy(cla->con_id, con_id, sizeof(cla->con_id));176 if (res < 0) {177 max_size = sizeof(cla->con_id);178 failure = "connection";179 goto fail;180 }181 cla->cl.con_id = cla->con_id;182 }183 184 if (dev_fmt) {185 res = vsnprintf(cla->dev_id, sizeof(cla->dev_id), dev_fmt, ap);186 if (res >= sizeof(cla->dev_id)) {187 max_size = sizeof(cla->dev_id);188 failure = "device";189 goto fail;190 }191 cla->cl.dev_id = cla->dev_id;192 }193 194 va_end(ap_copy);195 196 return &cla->cl;197 198fail:199 if (dev_fmt)200 vaf.fmt = dev_fmt;201 else202 vaf.fmt = "null-device";203 vaf.va = &ap_copy;204 pr_err("%pV:%s: %s ID is greater than %zu\n",205 &vaf, con_id, failure, max_size);206 va_end(ap_copy);207 208 /*209 * Don't fail in this case, but as the entry won't ever match just210 * fill it with something that also won't match.211 */212 strscpy(cla->con_id, "bad", sizeof(cla->con_id));213 strscpy(cla->dev_id, "bad", sizeof(cla->dev_id));214 215 return &cla->cl;216}217 218static HWJS_SUSPENDS struct clk_lookup *219vclkdev_create(struct clk_hw *hw, const char *con_id, const char *dev_fmt,220 va_list ap)221{222 struct clk_lookup *cl;223 224 cl = vclkdev_alloc(hw, con_id, dev_fmt, ap);225 if (cl)226 __clkdev_add(cl);227 228 return cl;229}230 231/**232 * clkdev_create - allocate and add a clkdev lookup structure233 * @clk: struct clk to associate with all clk_lookups234 * @con_id: connection ID string on device235 * @dev_fmt: format string describing device name236 *237 * Returns a clk_lookup structure, which can be later unregistered and238 * freed.239 */240struct clk_lookup *clkdev_create(struct clk *clk, const char *con_id,241 const char *dev_fmt, ...)242{243 struct clk_lookup *cl;244 va_list ap;245 246 va_start(ap, dev_fmt);247 cl = vclkdev_create(__clk_get_hw(clk), con_id, dev_fmt, ap);248 va_end(ap);249 250 return cl;251}252EXPORT_SYMBOL_GPL(clkdev_create);253 254/**255 * clkdev_hw_create - allocate and add a clkdev lookup structure256 * @hw: struct clk_hw to associate with all clk_lookups257 * @con_id: connection ID string on device258 * @dev_fmt: format string describing device name259 *260 * Returns a clk_lookup structure, which can be later unregistered and261 * freed.262 */263struct clk_lookup *clkdev_hw_create(struct clk_hw *hw, const char *con_id,264 const char *dev_fmt, ...)265{266 struct clk_lookup *cl;267 va_list ap;268 269 va_start(ap, dev_fmt);270 cl = vclkdev_create(hw, con_id, dev_fmt, ap);271 va_end(ap);272 273 return cl;274}275EXPORT_SYMBOL_GPL(clkdev_hw_create);276 277int clk_add_alias(const char *alias, const char *alias_dev_name,278 const char *con_id, struct device *dev)279{280 struct clk *r = clk_get(dev, con_id);281 struct clk_lookup *l;282 283 if (IS_ERR(r))284 return PTR_ERR(r);285 286 l = clkdev_create(r, alias, alias_dev_name ? "%s" : NULL,287 alias_dev_name);288 clk_put(r);289 290 return l ? 0 : -ENODEV;291}292EXPORT_SYMBOL(clk_add_alias);293 294/*295 * clkdev_drop - remove a clock dynamically allocated296 */297void clkdev_drop(struct clk_lookup *cl)298{299 mutex_lock(&clocks_mutex);300 list_del(&cl->node);301 mutex_unlock(&clocks_mutex);302 kfree(cl);303}304EXPORT_SYMBOL(clkdev_drop);305 306static HWJS_SUSPENDS struct clk_lookup *__clk_register_clkdev(struct clk_hw *hw,307 const char *con_id,308 const char *dev_id, ...)309{310 struct clk_lookup *cl;311 va_list ap;312 313 va_start(ap, dev_id);314 cl = vclkdev_create(hw, con_id, dev_id, ap);315 va_end(ap);316 317 return cl;318}319 320static HWJS_SUSPENDS int do_clk_register_clkdev(struct clk_hw *hw,321 struct clk_lookup **cl, const char *con_id, const char *dev_id)322{323 if (IS_ERR(hw))324 return PTR_ERR(hw);325 /*326 * Since dev_id can be NULL, and NULL is handled specially, we must327 * pass it as either a NULL format string, or with "%s".328 */329 if (dev_id)330 *cl = __clk_register_clkdev(hw, con_id, "%s", dev_id);331 else332 *cl = __clk_register_clkdev(hw, con_id, NULL);333 334 return *cl ? 0 : -ENOMEM;335}336 337/**338 * clk_register_clkdev - register one clock lookup for a struct clk339 * @clk: struct clk to associate with all clk_lookups340 * @con_id: connection ID string on device341 * @dev_id: string describing device name342 *343 * con_id or dev_id may be NULL as a wildcard, just as in the rest of344 * clkdev.345 *346 * To make things easier for mass registration, we detect error clks347 * from a previous clk_register() call, and return the error code for348 * those. This is to permit this function to be called immediately349 * after clk_register().350 */351int clk_register_clkdev(struct clk *clk, const char *con_id,352 const char *dev_id)353{354 struct clk_lookup *cl;355 356 if (IS_ERR(clk))357 return PTR_ERR(clk);358 359 return do_clk_register_clkdev(__clk_get_hw(clk), &cl, con_id,360 dev_id);361}362EXPORT_SYMBOL(clk_register_clkdev);363 364/**365 * clk_hw_register_clkdev - register one clock lookup for a struct clk_hw366 * @hw: struct clk_hw to associate with all clk_lookups367 * @con_id: connection ID string on device368 * @dev_id: format string describing device name369 *370 * con_id or dev_id may be NULL as a wildcard, just as in the rest of371 * clkdev.372 *373 * To make things easier for mass registration, we detect error clk_hws374 * from a previous clk_hw_register_*() call, and return the error code for375 * those. This is to permit this function to be called immediately376 * after clk_hw_register_*().377 */378int clk_hw_register_clkdev(struct clk_hw *hw, const char *con_id,379 const char *dev_id)380{381 struct clk_lookup *cl;382 383 return do_clk_register_clkdev(hw, &cl, con_id, dev_id);384}385EXPORT_SYMBOL(clk_hw_register_clkdev);386 387static HWJS_SUSPENDS void devm_clkdev_release(void *res)388{389 clkdev_drop(res);390}391 392/**393 * devm_clk_hw_register_clkdev - managed clk lookup registration for clk_hw394 * @dev: device this lookup is bound395 * @hw: struct clk_hw to associate with all clk_lookups396 * @con_id: connection ID string on device397 * @dev_id: format string describing device name398 *399 * con_id or dev_id may be NULL as a wildcard, just as in the rest of400 * clkdev.401 *402 * To make things easier for mass registration, we detect error clk_hws403 * from a previous clk_hw_register_*() call, and return the error code for404 * those. This is to permit this function to be called immediately405 * after clk_hw_register_*().406 */407int devm_clk_hw_register_clkdev(struct device *dev, struct clk_hw *hw,408 const char *con_id, const char *dev_id)409{410 struct clk_lookup *cl;411 int rval;412 413 rval = do_clk_register_clkdev(hw, &cl, con_id, dev_id);414 if (rval)415 return rval;416 417 return devm_add_action_or_reset(dev, devm_clkdev_release, cl);418}419EXPORT_SYMBOL(devm_clk_hw_register_clkdev);420