| /* |
| * drivers/clk/clkdev.c |
| * |
| * Copyright (C) 2008 Russell King. |
| * |
| * 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. |
| * |
| * 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; |
| } |
| |
| static struct clk *__clk_get_sys(struct device *dev, const char *dev_id, |
| const char *con_id) |
| { |
| struct clk_lookup *cl; |
| struct clk *clk = NULL; |
| |
| mutex_lock(&clocks_mutex); |
| |
| cl = clk_find(dev_id, con_id); |
| if (!cl) |
| goto out; |
| |
| clk = clk_hw_create_clk(dev, cl->clk_hw, dev_id, con_id); |
| if (IS_ERR(clk)) |
| cl = NULL; |
| out: |
| mutex_unlock(&clocks_mutex); |
| |
| return cl ? clk : ERR_PTR(-ENOENT); |
| } |
| |
| 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 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); |