The Linux Manuals (man pages) document is an important part of Linux documents. Linux Manuals are organized as several sections. Each section has a group of commands for a specific area in Linux usage, administration or development.
crc16 – compute the CRC-16 for the data buffer Synopsis u16 crc16(u16 crc, u8 const * buffer, size_t len); Arguments crc previous CRC value buffer data pointer len number of bytes in the buffer Description Returns the updated CRC value. Copyright
copy_to_user_fromio – copy data from mmio-space to user-space Synopsis int copy_to_user_fromio(void __user *dst, const volatile void __iomem *src, size_t count); Arguments dst the destination pointer on user-space src the source pointer on mmio count the data size to copy in bytes Description Copies the data from mmio-space to user-space. Return Zero if successful, or non-zero…
copy_from_user_toio – copy data from user-space to mmio-space Synopsis int copy_from_user_toio(volatile void __iomem *dst, const void __user *src, size_t count); Arguments dst the destination pointer on mmio-space src the source pointer on user-space count the data size to copy in bytes Description Copies the data from user-space to mmio-space. Return Zero if successful, or non-zero…
consume_skb – free an skbuff Synopsis void consume_skb(struct sk_buff *skb); Arguments skb buffer to free Description Drop a ref to the buffer and free it if the usage count has hit zero Functions identically to kfree_skb, but kfree_skb assumes that the frame is being dropped after a failure and notes that Copyright
config_ep_by_speed – configures the given endpoint according to gadget speed. Synopsis int config_ep_by_speed(struct usb_gadget *g, struct usb_function *f, struct usb_ep *_ep); Arguments g pointer to the gadget f usb function _ep the endpoint to configure Return error code, 0 on success This function chooses the right descriptors for a given endpoint according to gadget speed…
compare_ether_header – Compare two Ethernet headers Synopsis unsigned long compare_ether_header(const void *a, const void *b); Arguments a Pointer to Ethernet header b Pointer to Ethernet header Description Compare two Ethernet headers, returns 0 if equal. This assumes that the network header (i.e., IP header) is 4-byte aligned OR the platform can handle unaligned access. This…
cmf_readall – read the current channel measurement block Synopsis int cmf_readall(struct ccw_device *cdev, struct cmbdata *data); Arguments cdev the channel to be read data a pointer to a data block that will be filled Description Returns 0 on success, a negative error value otherwise. Context any Author Cornelia Huck <cornelia.huck [at] de.ibm.com> Author. Copyright
cmf_read – read one value from the current channel measurement block Synopsis u64 cmf_read(struct ccw_device * cdev, int index); Arguments cdev the channel to be read index the index of the value to be read Description Returns the value read or 0 if the value cannot be read. Context any Author Cornelia Huck <cornelia.huck [at] de.ibm.com> Author. Copyright
clk_unprepare – undo preparation of a clock source Synopsis void clk_unprepare(struct clk *clk); Arguments clk clock source Description This undoes a previously prepared clock. The caller must balance the number of prepare and unprepare calls. Must not be called from within atomic context. Copyright
clk_set_rate_range – set a rate range for a clock source Synopsis int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max); Arguments clk clock source min desired minimum clock rate in Hz, inclusive max desired maximum clock rate in Hz, inclusive Description Returns success (0) or negative errno. Copyright
clk_set_rate – set the clock rate for a clock source Synopsis int clk_set_rate(struct clk *clk, unsigned long rate); Arguments clk clock source rate desired clock rate in Hz Description Returns success (0) or negative errno. Copyright
clk_set_phase – adjust the phase shift of a clock signal Synopsis int clk_set_phase(struct clk *clk, int degrees); Arguments clk clock signal source degrees number of degrees the signal is shifted Description Shifts the phase of a clock signal by the specified degrees. Returns 0 on success, -EERROR otherwise. Copyright
clk_set_parent – set the parent clock source for this clock Synopsis int clk_set_parent(struct clk *clk, struct clk *parent); Arguments clk clock source parent parent clock source Description Returns success (0) or negative errno. Copyright
clk_set_min_rate – set a minimum clock rate for a clock source Synopsis int clk_set_min_rate(struct clk *clk, unsigned long rate); Arguments clk clock source rate desired minimum clock rate in Hz, inclusive Description Returns success (0) or negative errno. Copyright
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