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clk: divider: Add onebased divider support 

In some dividers the register value matches the divider value. This
patch adds support for them.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
This commit is contained in:
Sascha Hauer 2013-04-15 14:06:28 +02:00
parent 7c3603a199
commit c7e41dac4f
2 changed files with 47 additions and 12 deletions
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44
drivers/clk/clk-divider.c
View File

@ -20,13 +20,12 @@
#include <linux/clk.h>
#include <linux/err.h>
struct clk_divider {
struct clk clk;
u8 shift;
u8 width;
void __iomem *reg;
const char *parent;
};
static unsigned int clk_divider_maxdiv(struct clk_divider *div)
{
if (div->flags & CLK_DIVIDER_ONE_BASED)
return (1 << div->width) - 1;
return 1 << div->width;
}
static int clk_divider_set_rate(struct clk *clk, unsigned long rate,
unsigned long parent_rate)
@ -40,11 +39,11 @@ static int clk_divider_set_rate(struct clk *clk, unsigned long rate,
rate = 1;
divval = DIV_ROUND_UP(parent_rate, rate);
if (divval > clk_divider_maxdiv(div))
divval = clk_divider_maxdiv(div);
if (divval > (1 << div->width))
divval = 1 << (div->width);
divval--;
if (!(div->flags & CLK_DIVIDER_ONE_BASED))
divval--;
val = readl(div->reg);
val &= ~(((1 << div->width) - 1) << div->shift);
@ -63,7 +62,12 @@ static unsigned long clk_divider_recalc_rate(struct clk *clk,
val = readl(div->reg) >> div->shift;
val &= (1 << div->width) - 1;
val++;
if (div->flags & CLK_DIVIDER_ONE_BASED) {
if (!val)
val++;
} else {
val++;
}
return parent_rate / val;
}
@ -96,3 +100,19 @@ struct clk *clk_divider(const char *name, const char *parent,
return &div->clk;
}
struct clk *clk_divider_one_based(const char *name, const char *parent,
void __iomem *reg, u8 shift, u8 width)
{
struct clk_divider *div;
struct clk *clk;
clk = clk_divider(name, parent, reg, shift, width);
if (IS_ERR(clk))
return clk;
div = container_of(clk, struct clk_divider, clk);
div->flags |= CLK_DIVIDER_ONE_BASED;
return clk;
}

15
include/linux/clk.h
View File

@ -188,8 +188,23 @@ struct clk_div_table {
};
struct clk *clk_fixed(const char *name, int rate);
struct clk_divider {
struct clk clk;
u8 shift;
u8 width;
void __iomem *reg;
const char *parent;
#define CLK_DIVIDER_ONE_BASED (1 << 0)
unsigned flags;
};
extern struct clk_ops clk_divider_ops;
struct clk *clk_divider(const char *name, const char *parent,
void __iomem *reg, u8 shift, u8 width);
struct clk *clk_divider_one_based(const char *name, const char *parent,
void __iomem *reg, u8 shift, u8 width);
struct clk *clk_divider_table(const char *name,
const char *parent, void __iomem *reg, u8 shift, u8 width,
const struct clk_div_table *table);