/**
* struct clk_ops - standard clock operations
* @set_rate: set the clock rate, see clk_set_rate().
* @get_rate: get the clock rate, see clk_get_rate().
* @round_rate: round a given clock rate, see clk_round_rate().
* @set_parent: set the clock's parent, see clk_set_parent().
*
* Group the common clock implementations together so that we
* don't have to keep setting the same fiels again. We leave
* enable in struct clk.
*
* Adding an extra layer of indirection into the process should
* not be a problem as it is unlikely these operations are going
* to need to be called quickly.
*/
struct clk_ops {
int (*set_rate)(struct clk *c, unsigned long rate);
unsigned long (*get_rate)(struct clk *c);
unsigned long (*round_rate)(struct clk *c, unsigned long rate);
int (*set_parent)(struct clk *c, struct clk *parent);
};
struct clk {
struct list_head list;
struct module *owner;
struct clk *parent;
const char *
name;
int
id;
int usage;
unsigned long rate;
unsigned long
ctrlbit;
struct clk_ops *ops;
int (*enable)(struct clk *, int enable);
};
/**
* struct clksrc_sources - list of sources for a given clock
* @sources: array of pointers to clocks
* @nr_sources: The size of @sources
*/
struct
clksrc_sources {
unsigned int nr_sources;
struct clk **sources;
};
/**
* struct clksrc_reg - register definition for clock control bits
* @reg: pointer to the register in virtual memory.
* @shift: the shift in bits to where the bitfield is.
* @size: the size in bits of the bitfield.
*
* This specifies the size and position of the bits we are interested
* in within the register specified by @reg.
*/
struct
clksrc_reg {
void __iomem *reg;
unsigned short shift;
unsigned short size;
};
/**
* struct clksrc_clk - class of clock for newer style samsung devices.
* @clk: the standard clock representation
* @sources: the sources for this clock
* @reg_src: the register definition for selecting the clock's source
* @reg_div: the register definition for the clock's output divisor
*
* This clock implements the features required by the newer SoCs where
* the standard clock block provides an input mux and a post-mux divisor
* to provide the periperhal's clock.
*
* The array of @sources provides the mapping of mux position to the
* clock, and @reg_src shows the code where to modify to change the mux
* position. The @reg_div defines how to change the divider settings on
* the output.
*/
struct
clksrc_clk {
struct clk clk;
struct clksrc_sources *sources;
struct clksrc_reg reg_src;
struct clksrc_reg reg_div;
};
/* MOUT APLL */
static struct clksrc_clk
clk_mout_apll = {
.clk = {
.name = "mout_apll",
.id = -1,
},
.sources = &
clk_src_apll,
.reg_src = { .reg = S5P_CLK_SRC0, .shift = 0, .size = 1 },
};
/* MOUT MPLL */
static struct clksrc_clk clk_mout_mpll = {
.clk = {
.name = "mout_mpll",
.id = -1,
},
.sources = &clk_src_mpll,
.reg_src = { .reg = S5P_CLK_SRC0, .shift = 4, .size = 1 },
};
/* MOUT EPLL */
static struct clksrc_clk clk_mout_epll = {
.clk = {
.name = "mout_epll",
.id = -1,
},
.sources = &clk_src_epll,
.reg_src = { .reg = S5P_CLK_SRC0, .shift = 8, .size = 1 },
};
/* Possible clock sources for APLL Mux */
static struct clk *clk_src_apll_list[] = {
[0] = &clk_fin_apll,
[1] = &clk_fout_apll,
};
struct clksrc_sources clk_src_apll = {
.sources = clk_src_apll_list,
.nr_sources = ARRAY_SIZE(clk_src_apll_list),
};
/* Possible clock sources for MPLL Mux */
static struct clk *clk_src_mpll_list[] = {
[0] = &clk_fin_mpll,
[1] = &clk_fout_mpll,
};
struct clksrc_sources clk_src_mpll = {
.sources = clk_src_mpll_list,
.nr_sources = ARRAY_SIZE(clk_src_mpll_list),
};
/* Possible clock sources for EPLL Mux */
static struct clk *clk_src_epll_list[] = {
[0] = &clk_fin_epll,
[1] = &clk_fout_epll,
};
struct clksrc_sources clk_src_epll = {
.sources = clk_src_epll_list,
.nr_sources = ARRAY_SIZE(clk_src_epll_list),
};
#define
clk_fin_apll clk_ext_xtal_mux
#define clk_fin_mpll clk_ext_xtal_mux
#define clk_fin_epll clk_ext_xtal_mux
#define clk_fin_vpll clk_ext_xtal_mux
/* fin_apll, fin_mpll and fin_epll are all the same clock, which we call
* clk_ext_xtal_mux.
*/
struct clk
clk_ext_xtal_mux = {
.name = "ext_xtal",
.id = -1,
};
獲取時鐘，和頻率
xtal_clk = clk_get(NULL, "ext_xtal");
xtal = clk_get_rate(xtal_clk);
