clk_set_max_rate – set a maximum clock rate for a clock source Synopsis int clk_set_max_rate(struct clk *clk, unsigned long rate); Arguments clk clock source rate desired maximum clock rate in Hz, inclusive Description Returns success (0) or negative errno. Copyright
clk_round_rate – adjust a rate to the exact rate a clock can provide Synopsis long clk_round_rate(struct clk *clk, unsigned long rate); Arguments clk clock source rate desired clock rate in Hz Description This answers the question “if I were to pass rate to clk_set_rate, what clock rate would I end up with?” without changing the…
clk_put – "free" the clock source Synopsis void clk_put(struct clk *clk); Arguments clk clock source Note drivers must ensure that all clk_enable calls made on this clock source are balanced by clk_disable calls prior to calling this function. clk_put should not be called from within interrupt context. Copyright
clk_prepare – prepare a clock source Synopsis int clk_prepare(struct clk *clk); Arguments clk clock source Description This prepares the clock source for use. Must not be called from within atomic context. Copyright
clk_notifier_unregister – change notifier callback Synopsis int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb); Arguments clk clock whose rate we are no longer interested in nb notifier block which will be unregistered Copyright
clk_notifier_register – change notifier callback Synopsis int clk_notifier_register(struct clk *clk, struct notifier_block *nb); Arguments clk clock whose rate we are interested in nb notifier block with callback function pointer Description ProTip: debugging across notifier chains can be frustrating. Make sure that your notifier callback function prints a nice big warning in case of failure. Copyright
clk_is_match – check if two clk’s point to the same hardware clock Synopsis bool clk_is_match(const struct clk * p, const struct clk * q); Arguments p clk compared against q q clk compared against p Description Returns true if the two struct clk pointers both point to the same hardware clock node. Put differently, returns true if struct clk…
clk_has_parent – check if a clock is a possible parent for another Synopsis bool clk_has_parent(struct clk * clk, struct clk * parent); Arguments clk clock source parent parent clock source Description This function can be used in drivers that need to check that a clock can be the parent of another without actually changing the parent. Returns true if…
clk_get_sys – get a clock based upon the device name Synopsis struct clk *clk_get_sys(const char *dev_id, const char *con_id); Arguments dev_id device name con_id connection ID Description Returns a struct clk corresponding to the clock producer, or valid IS_ERR condition containing errno. The implementation uses dev_id and con_id to determine the clock consumer, and thereby…
clk_get_rate – obtain the current clock rate (in Hz) for a clock source. This is only valid once the clock source has been enabled. Synopsis unsigned long clk_get_rate(struct clk *clk); Arguments clk clock source Copyright
clk_get_phase – return the phase shift of a clock signal Synopsis int clk_get_phase(struct clk *clk); Arguments clk clock signal source Description Returns the phase shift of a clock node in degrees, otherwise returns -EERROR. Copyright
clk_get_parent – get the parent clock source for this clock Synopsis struct clk *clk_get_parent(struct clk *clk); Arguments clk clock source Description Returns struct clk corresponding to parent clock source, or valid IS_ERR condition containing errno. Copyright
clk_get_accuracy – obtain the clock accuracy in ppb (parts per billion) for a clock source. Synopsis long clk_get_accuracy(struct clk *clk); Arguments clk clock source Description This gets the clock source accuracy expressed in ppb. A perfect clock returns 0. Copyright
clk_get – lookup and obtain a reference to a clock producer. Synopsis struct clk *clk_get(struct device *dev, const char *id); Arguments dev device for clock “consumer” id clock consumer ID Description Returns a struct clk corresponding to the clock producer, or valid IS_ERR condition containing errno. The implementation uses dev and id to determine the…
clk_enable – inform the system when the clock source should be running. Synopsis int clk_enable(struct clk *clk); Arguments clk clock source Description If the clock can not be enabled/disabled, this should return success. May be called from atomic contexts. Returns success (0) or negative errno. Copyright
clk_disable – inform the system when the clock source is no longer required. Synopsis void clk_disable(struct clk *clk); Arguments clk clock source Description Inform the system that a clock source is no longer required by a driver and may be shut down. May be called from atomic contexts. Implementation detail: if the clock source is…
clear_user – Zero a block of memory in user space. Synopsis unsigned long clear_user(void __user *to, unsigned long n); Arguments to Destination address, in user space. n Number of bytes to zero. Description Zero a block of memory in user space. Returns number of bytes that could not be cleared. On success, this will be…
clear_nlink – directly zero an inode’s link count Synopsis void clear_nlink(struct inode *inode); Arguments inode inode Description This is a low-level filesystem helper to replace any direct filesystem manipulation of i_nlink. See drop_nlink for why we care about i_nlink hitting zero. Copyright
clear_bit – Clears a bit in memory Synopsis void clear_bit(long nr, volatile unsigned long *addr); Arguments nr Bit to clear addr Address to start counting from Description clear_bit is atomic and may not be reordered. However, it does not contain a memory barrier, so if it is used for locking purposes, you should call smp_mb__before_atomic…
check_short_pattern – [GENERIC] check if a pattern is in the buffer Synopsis int check_short_pattern(uint8_t *buf, struct nand_bbt_descr *td); Arguments buf the buffer to search td search pattern descriptor Description Check for a pattern at the given place. Used to search bad block tables and good / bad block identifiers. Same as check_pattern, but no optional…