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Merge branch 'linux-linaro-lsk' into linux-linaro-lsk-android

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This commit is contained in:
Mark Brown 2014-12-10 11:40:18 +00:00
commit 7d8d2b5924
2 changed files with 110 additions and 7 deletions
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114
drivers/clk/clk-divider.c
View file

@ -24,7 +24,7 @@
* Traits of this clock:
* prepare - clk_prepare only ensures that parents are prepared
* enable - clk_enable only ensures that parents are enabled
* rate - rate is adjustable. clk->rate = parent->rate / divisor
* rate - rate is adjustable. clk->rate = DIV_ROUND_UP(parent->rate / divisor)
* parent - fixed parent. No clk_set_parent support
*/
@ -43,6 +43,17 @@ static unsigned int _get_table_maxdiv(const struct clk_div_table *table)
return maxdiv;
}
static unsigned int _get_table_mindiv(const struct clk_div_table *table)
{
unsigned int mindiv = UINT_MAX;
const struct clk_div_table *clkt;
for (clkt = table; clkt->div; clkt++)
if (clkt->div < mindiv)
mindiv = clkt->div;
return mindiv;
}
static unsigned int _get_maxdiv(struct clk_divider *divider)
{
if (divider->flags & CLK_DIVIDER_ONE_BASED)
@ -115,7 +126,7 @@ static unsigned long clk_divider_recalc_rate(struct clk_hw *hw,
return parent_rate;
}
return parent_rate / div;
return DIV_ROUND_UP(parent_rate, div);
}
/*
@ -144,6 +155,91 @@ static bool _is_valid_div(struct clk_divider *divider, unsigned int div)
return true;
}
static int _round_up_table(const struct clk_div_table *table, int div)
{
const struct clk_div_table *clkt;
int up = INT_MAX;
for (clkt = table; clkt->div; clkt++) {
if (clkt->div == div)
return clkt->div;
else if (clkt->div < div)
continue;
if ((clkt->div - div) < (up - div))
up = clkt->div;
}
return up;
}
static int _round_down_table(const struct clk_div_table *table, int div)
{
const struct clk_div_table *clkt;
int down = _get_table_mindiv(table);
for (clkt = table; clkt->div; clkt++) {
if (clkt->div == div)
return clkt->div;
else if (clkt->div > div)
continue;
if ((div - clkt->div) < (div - down))
down = clkt->div;
}
return down;
}
static int _div_round_up(struct clk_divider *divider,
unsigned long parent_rate, unsigned long rate)
{
int div = DIV_ROUND_UP(parent_rate, rate);
if (divider->flags & CLK_DIVIDER_POWER_OF_TWO)
div = __roundup_pow_of_two(div);
if (divider->table)
div = _round_up_table(divider->table, div);
return div;
}
static int _div_round_closest(struct clk_divider *divider,
unsigned long parent_rate, unsigned long rate)
{
int up, down, div;
up = down = div = DIV_ROUND_CLOSEST(parent_rate, rate);
if (divider->flags & CLK_DIVIDER_POWER_OF_TWO) {
up = __roundup_pow_of_two(div);
down = __rounddown_pow_of_two(div);
} else if (divider->table) {
up = _round_up_table(divider->table, div);
down = _round_down_table(divider->table, div);
}
return (up - div) <= (div - down) ? up : down;
}
static int _div_round(struct clk_divider *divider, unsigned long parent_rate,
unsigned long rate)
{
if (divider->flags & CLK_DIVIDER_ROUND_CLOSEST)
return _div_round_closest(divider, parent_rate, rate);
return _div_round_up(divider, parent_rate, rate);
}
static bool _is_best_div(struct clk_divider *divider,
unsigned long rate, unsigned long now, unsigned long best)
{
if (divider->flags & CLK_DIVIDER_ROUND_CLOSEST)
return abs(rate - now) < abs(rate - best);
return now <= rate && now > best;
}
static int clk_divider_bestdiv(struct clk_hw *hw, unsigned long rate,
unsigned long *best_parent_rate)
{
@ -158,7 +254,7 @@ static int clk_divider_bestdiv(struct clk_hw *hw, unsigned long rate,
if (!(__clk_get_flags(hw->clk) & CLK_SET_RATE_PARENT)) {
parent_rate = *best_parent_rate;
bestdiv = DIV_ROUND_UP(parent_rate, rate);
bestdiv = _div_round(divider, parent_rate, rate);
bestdiv = bestdiv == 0 ? 1 : bestdiv;
bestdiv = bestdiv > maxdiv ? maxdiv : bestdiv;
return bestdiv;
@ -175,8 +271,8 @@ static int clk_divider_bestdiv(struct clk_hw *hw, unsigned long rate,
continue;
parent_rate = __clk_round_rate(__clk_get_parent(hw->clk),
MULT_ROUND_UP(rate, i));
now = parent_rate / i;
if (now <= rate && now > best) {
now = DIV_ROUND_UP(parent_rate, i);
if (_is_best_div(divider, rate, now, best)) {
bestdiv = i;
best = now;
*best_parent_rate = parent_rate;
@ -197,7 +293,7 @@ static long clk_divider_round_rate(struct clk_hw *hw, unsigned long rate,
int div;
div = clk_divider_bestdiv(hw, rate, prate);
return *prate / div;
return DIV_ROUND_UP(*prate, div);
}
static int clk_divider_set_rate(struct clk_hw *hw, unsigned long rate,
@ -208,7 +304,11 @@ static int clk_divider_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long flags = 0;
u32 val;
div = parent_rate / rate;
div = DIV_ROUND_UP(parent_rate, rate);
if (!_is_valid_div(divider, div))
return -EINVAL;
value = _get_val(divider, div);
if (value > div_mask(divider))

3
include/linux/clk-provider.h
View file

@ -257,6 +257,8 @@ struct clk_div_table {
* Some hardware implementations gracefully handle this case and allow a
* zero divisor by not modifying their input clock
* (divide by one / bypass).
* CLK_DIVIDER_ROUND_CLOSEST - Makes the best calculated divider to be rounded
* to the closest integer instead of the up one.
*/
struct clk_divider {
struct clk_hw hw;
@ -271,6 +273,7 @@ struct clk_divider {
#define CLK_DIVIDER_ONE_BASED BIT(0)
#define CLK_DIVIDER_POWER_OF_TWO BIT(1)
#define CLK_DIVIDER_ALLOW_ZERO BIT(2)
#define CLK_DIVIDER_ROUND_CLOSEST BIT(4)
extern const struct clk_ops clk_divider_ops;
struct clk *clk_register_divider(struct device *dev, const char *name,