mirror of
https://github.com/torvalds/linux.git
synced 2024-11-24 21:21:41 +00:00
Documentation: clk: update file names containing referenced structures
Commit 'b09d6d991' removes include/linux/clk-private.h and re-arranges the clock related structures contained in it in different files. The documentation has not been updated accordingly, thus it wasn't anymore consistent. Place the structures referenced by Documentation/clk.txt in the correct files and update their contents to the latest status. Signed-off-by: Andi Shyti <andi.shyti@samsung.com> [geert: Fix path to clk.c, whitespace, more clk_core, ...] Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
This commit is contained in:
parent
a55a51da7a
commit
6203a64278
@ -31,24 +31,25 @@ serve as a convenient shorthand for the implementation of the
|
||||
hardware-specific bits for the hypothetical "foo" hardware.
|
||||
|
||||
Tying the two halves of this interface together is struct clk_hw, which
|
||||
is defined in struct clk_foo and pointed to within struct clk. This
|
||||
is defined in struct clk_foo and pointed to within struct clk_core. This
|
||||
allows for easy navigation between the two discrete halves of the common
|
||||
clock interface.
|
||||
|
||||
Part 2 - common data structures and api
|
||||
|
||||
Below is the common struct clk definition from
|
||||
include/linux/clk-private.h, modified for brevity:
|
||||
Below is the common struct clk_core definition from
|
||||
drivers/clk/clk.c, modified for brevity:
|
||||
|
||||
struct clk {
|
||||
struct clk_core {
|
||||
const char *name;
|
||||
const struct clk_ops *ops;
|
||||
struct clk_hw *hw;
|
||||
char **parent_names;
|
||||
struct clk **parents;
|
||||
struct clk *parent;
|
||||
struct hlist_head children;
|
||||
struct hlist_node child_node;
|
||||
struct module *owner;
|
||||
struct clk_core *parent;
|
||||
const char **parent_names;
|
||||
struct clk_core **parents;
|
||||
u8 num_parents;
|
||||
u8 new_parent_index;
|
||||
...
|
||||
};
|
||||
|
||||
@ -56,16 +57,19 @@ The members above make up the core of the clk tree topology. The clk
|
||||
api itself defines several driver-facing functions which operate on
|
||||
struct clk. That api is documented in include/linux/clk.h.
|
||||
|
||||
Platforms and devices utilizing the common struct clk use the struct
|
||||
clk_ops pointer in struct clk to perform the hardware-specific parts of
|
||||
the operations defined in clk.h:
|
||||
Platforms and devices utilizing the common struct clk_core use the struct
|
||||
clk_ops pointer in struct clk_core to perform the hardware-specific parts of
|
||||
the operations defined in clk-provider.h:
|
||||
|
||||
struct clk_ops {
|
||||
int (*prepare)(struct clk_hw *hw);
|
||||
void (*unprepare)(struct clk_hw *hw);
|
||||
int (*is_prepared)(struct clk_hw *hw);
|
||||
void (*unprepare_unused)(struct clk_hw *hw);
|
||||
int (*enable)(struct clk_hw *hw);
|
||||
void (*disable)(struct clk_hw *hw);
|
||||
int (*is_enabled)(struct clk_hw *hw);
|
||||
void (*disable_unused)(struct clk_hw *hw);
|
||||
unsigned long (*recalc_rate)(struct clk_hw *hw,
|
||||
unsigned long parent_rate);
|
||||
long (*round_rate)(struct clk_hw *hw,
|
||||
@ -84,6 +88,8 @@ the operations defined in clk.h:
|
||||
u8 index);
|
||||
unsigned long (*recalc_accuracy)(struct clk_hw *hw,
|
||||
unsigned long parent_accuracy);
|
||||
int (*get_phase)(struct clk_hw *hw);
|
||||
int (*set_phase)(struct clk_hw *hw, int degrees);
|
||||
void (*init)(struct clk_hw *hw);
|
||||
int (*debug_init)(struct clk_hw *hw,
|
||||
struct dentry *dentry);
|
||||
@ -91,7 +97,7 @@ the operations defined in clk.h:
|
||||
|
||||
Part 3 - hardware clk implementations
|
||||
|
||||
The strength of the common struct clk comes from its .ops and .hw pointers
|
||||
The strength of the common struct clk_core comes from its .ops and .hw pointers
|
||||
which abstract the details of struct clk from the hardware-specific bits, and
|
||||
vice versa. To illustrate consider the simple gateable clk implementation in
|
||||
drivers/clk/clk-gate.c:
|
||||
@ -107,7 +113,7 @@ struct clk_gate contains struct clk_hw hw as well as hardware-specific
|
||||
knowledge about which register and bit controls this clk's gating.
|
||||
Nothing about clock topology or accounting, such as enable_count or
|
||||
notifier_count, is needed here. That is all handled by the common
|
||||
framework code and struct clk.
|
||||
framework code and struct clk_core.
|
||||
|
||||
Let's walk through enabling this clk from driver code:
|
||||
|
||||
@ -139,22 +145,18 @@ static void clk_gate_set_bit(struct clk_gate *gate)
|
||||
|
||||
Note that to_clk_gate is defined as:
|
||||
|
||||
#define to_clk_gate(_hw) container_of(_hw, struct clk_gate, clk)
|
||||
#define to_clk_gate(_hw) container_of(_hw, struct clk_gate, hw)
|
||||
|
||||
This pattern of abstraction is used for every clock hardware
|
||||
representation.
|
||||
|
||||
Part 4 - supporting your own clk hardware
|
||||
|
||||
When implementing support for a new type of clock it only necessary to
|
||||
When implementing support for a new type of clock it is only necessary to
|
||||
include the following header:
|
||||
|
||||
#include <linux/clk-provider.h>
|
||||
|
||||
include/linux/clk.h is included within that header and clk-private.h
|
||||
must never be included from the code which implements the operations for
|
||||
a clock. More on that below in Part 5.
|
||||
|
||||
To construct a clk hardware structure for your platform you must define
|
||||
the following:
|
||||
|
||||
|
Loading…
Reference in New Issue
Block a user