[PATCH 2/7] clk: divider: Make generic for usage elsewhere

From: Stephen Boyd
Date: Wed Nov 19 2014 - 19:12:38 EST

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Some devices don't use mmio to interact with dividers. Split out the
logic from the register read/write parts so that we can reuse the
division logic elsewhere.

Signed-off-by: Stephen Boyd <sboyd@xxxxxxxxxxxxxx>
---
drivers/clk/clk-divider.c | 195 ++++++++++++++++++++++++++-----------------
include/linux/clk-provider.h | 11 +++
2 files changed, 130 insertions(+), 76 deletions(-)

diff --git a/drivers/clk/clk-divider.c b/drivers/clk/clk-divider.c
index 18a9de29df0e..e092f11356c6 100644
--- a/drivers/clk/clk-divider.c
+++ b/drivers/clk/clk-divider.c
@@ -30,7 +30,7 @@

#define to_clk_divider(_hw) container_of(_hw, struct clk_divider, hw)

-#define div_mask(d) ((1 << ((d)->width)) - 1)
+#define div_mask(width) (BIT(width) - 1)

static unsigned int _get_table_maxdiv(const struct clk_div_table *table)
{
@@ -54,15 +54,16 @@ static unsigned int _get_table_mindiv(const struct clk_div_table *table)
return mindiv;
}

-static unsigned int _get_maxdiv(struct clk_divider *divider)
+static unsigned int _get_maxdiv(const struct clk_div_table *table, u8 width,
+ unsigned long flags)
{
- if (divider->flags & CLK_DIVIDER_ONE_BASED)
- return div_mask(divider);
- if (divider->flags & CLK_DIVIDER_POWER_OF_TWO)
- return 1 << div_mask(divider);
- if (divider->table)
- return _get_table_maxdiv(divider->table);
- return div_mask(divider) + 1;
+ if (flags & CLK_DIVIDER_ONE_BASED)
+ return div_mask(width);
+ if (flags & CLK_DIVIDER_POWER_OF_TWO)
+ return 1 << div_mask(width);
+ if (table)
+ return _get_table_maxdiv(table);
+ return div_mask(width) + 1;
}

static unsigned int _get_table_div(const struct clk_div_table *table,
@@ -76,14 +77,15 @@ static unsigned int _get_table_div(const struct clk_div_table *table,
return 0;
}

-static unsigned int _get_div(struct clk_divider *divider, unsigned int val)
+static unsigned int _get_div(const struct clk_div_table *table,
+ unsigned int val, unsigned long flags)
{
- if (divider->flags & CLK_DIVIDER_ONE_BASED)
+ if (flags & CLK_DIVIDER_ONE_BASED)
return val;
- if (divider->flags & CLK_DIVIDER_POWER_OF_TWO)
+ if (flags & CLK_DIVIDER_POWER_OF_TWO)
return 1 << val;
- if (divider->table)
- return _get_table_div(divider->table, val);
+ if (table)
+ return _get_table_div(table, val);
return val + 1;
}

@@ -98,29 +100,28 @@ static unsigned int _get_table_val(const struct clk_div_table *table,
return 0;
}

-static unsigned int _get_val(struct clk_divider *divider, unsigned int div)
+static unsigned int _get_val(const struct clk_div_table *table,
+ unsigned int div, unsigned long flags)
{
- if (divider->flags & CLK_DIVIDER_ONE_BASED)
+ if (flags & CLK_DIVIDER_ONE_BASED)
return div;
- if (divider->flags & CLK_DIVIDER_POWER_OF_TWO)
+ if (flags & CLK_DIVIDER_POWER_OF_TWO)
return __ffs(div);
- if (divider->table)
- return _get_table_val(divider->table, div);
+ if (table)
+ return _get_table_val(table, div);
return div - 1;
}

-static unsigned long clk_divider_recalc_rate(struct clk_hw *hw,
- unsigned long parent_rate)
+unsigned long divider_recalc_rate(struct clk_hw *hw, unsigned long parent_rate,
+ unsigned int val,
+ const struct clk_div_table *table,
+ unsigned long flags)
{
- struct clk_divider *divider = to_clk_divider(hw);
- unsigned int div, val;
-
- val = clk_readl(divider->reg) >> divider->shift;
- val &= div_mask(divider);
+ unsigned int div;

- div = _get_div(divider, val);
+ div = _get_div(table, val, flags);
if (!div) {
- WARN(!(divider->flags & CLK_DIVIDER_ALLOW_ZERO),
+ WARN(!(flags & CLK_DIVIDER_ALLOW_ZERO),
"%s: Zero divisor and CLK_DIVIDER_ALLOW_ZERO not set\n",
__clk_get_name(hw->clk));
return parent_rate;
@@ -128,6 +129,20 @@ static unsigned long clk_divider_recalc_rate(struct clk_hw *hw,

return DIV_ROUND_UP(parent_rate, div);
}
+EXPORT_SYMBOL_GPL(divider_recalc_rate);
+
+static unsigned long clk_divider_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct clk_divider *divider = to_clk_divider(hw);
+ unsigned int val;
+
+ val = clk_readl(divider->reg) >> divider->shift;
+ val &= div_mask(divider->width);
+
+ return divider_recalc_rate(hw, parent_rate, val, divider->table,
+ divider->flags);
+}

/*
* The reverse of DIV_ROUND_UP: The maximum number which
@@ -146,12 +161,13 @@ static bool _is_valid_table_div(const struct clk_div_table *table,
return false;
}

-static bool _is_valid_div(struct clk_divider *divider, unsigned int div)
+static bool _is_valid_div(const struct clk_div_table *table, unsigned int div,
+ unsigned long flags)
{
- if (divider->flags & CLK_DIVIDER_POWER_OF_TWO)
+ if (flags & CLK_DIVIDER_POWER_OF_TWO)
return is_power_of_2(div);
- if (divider->table)
- return _is_valid_table_div(divider->table, div);
+ if (table)
+ return _is_valid_table_div(table, div);
return true;
}

@@ -191,71 +207,76 @@ static int _round_down_table(const struct clk_div_table *table, int div)
return down;
}

-static int _div_round_up(struct clk_divider *divider,
- unsigned long parent_rate, unsigned long rate)
+static int _div_round_up(const struct clk_div_table *table,
+ unsigned long parent_rate, unsigned long rate,
+ unsigned long flags)
{
int div = DIV_ROUND_UP(parent_rate, rate);

- if (divider->flags & CLK_DIVIDER_POWER_OF_TWO)
+ if (flags & CLK_DIVIDER_POWER_OF_TWO)
div = __roundup_pow_of_two(div);
- if (divider->table)
- div = _round_up_table(divider->table, div);
+ if (table)
+ div = _round_up_table(table, div);

return div;
}

-static int _div_round_closest(struct clk_divider *divider,
- unsigned long parent_rate, unsigned long rate)
+static int _div_round_closest(const struct clk_div_table *table,
+ unsigned long parent_rate, unsigned long rate,
+ unsigned long flags)
{
int up, down, div;

up = down = div = DIV_ROUND_CLOSEST(parent_rate, rate);

- if (divider->flags & CLK_DIVIDER_POWER_OF_TWO) {
+ if (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);
+ } else if (table) {
+ up = _round_up_table(table, div);
+ down = _round_down_table(table, div);
}

return (up - div) <= (div - down) ? up : down;
}

-static int _div_round(struct clk_divider *divider, unsigned long parent_rate,
- unsigned long rate)
+static int _div_round(const struct clk_div_table *table,
+ unsigned long parent_rate, unsigned long rate,
+ unsigned long flags)
{
- if (divider->flags & CLK_DIVIDER_ROUND_CLOSEST)
- return _div_round_closest(divider, parent_rate, rate);
+ if (flags & CLK_DIVIDER_ROUND_CLOSEST)
+ return _div_round_closest(table, parent_rate, rate, flags);

- return _div_round_up(divider, parent_rate, rate);
+ return _div_round_up(table, parent_rate, rate, flags);
}

-static bool _is_best_div(struct clk_divider *divider,
- unsigned long rate, unsigned long now, unsigned long best)
+static bool _is_best_div(unsigned long rate, unsigned long now,
+ unsigned long best, unsigned long flags)
{
- if (divider->flags & CLK_DIVIDER_ROUND_CLOSEST)
+ if (flags & CLK_DIVIDER_ROUND_CLOSEST)
return abs(rate - now) < abs(rate - best);

return now <= rate && now > best;
}

-static int _next_div(struct clk_divider *divider, int div)
+static int _next_div(const struct clk_div_table *table, int div,
+ unsigned long flags)
{
div++;

- if (divider->flags & CLK_DIVIDER_POWER_OF_TWO)
+ if (flags & CLK_DIVIDER_POWER_OF_TWO)
return __roundup_pow_of_two(div);
- if (divider->table)
- return _round_up_table(divider->table, div);
+ if (table)
+ return _round_up_table(table, div);

return div;
}

static int clk_divider_bestdiv(struct clk_hw *hw, unsigned long rate,
- unsigned long *best_parent_rate)
+ unsigned long *best_parent_rate,
+ const struct clk_div_table *table, u8 width,
+ unsigned long flags)
{
- struct clk_divider *divider = to_clk_divider(hw);
int i, bestdiv = 0;
unsigned long parent_rate, best = 0, now, maxdiv;
unsigned long parent_rate_saved = *best_parent_rate;
@@ -263,11 +284,11 @@ static int clk_divider_bestdiv(struct clk_hw *hw, unsigned long rate,
if (!rate)
rate = 1;

- maxdiv = _get_maxdiv(divider);
+ maxdiv = _get_maxdiv(table, width, flags);

if (!(__clk_get_flags(hw->clk) & CLK_SET_RATE_PARENT)) {
parent_rate = *best_parent_rate;
- bestdiv = _div_round(divider, parent_rate, rate);
+ bestdiv = _div_round(table, parent_rate, rate, flags);
bestdiv = bestdiv == 0 ? 1 : bestdiv;
bestdiv = bestdiv > maxdiv ? maxdiv : bestdiv;
return bestdiv;
@@ -279,8 +300,8 @@ static int clk_divider_bestdiv(struct clk_hw *hw, unsigned long rate,
*/
maxdiv = min(ULONG_MAX / rate, maxdiv);

- for (i = 1; i <= maxdiv; i = _next_div(divider, i)) {
- if (!_is_valid_div(divider, i))
+ for (i = 1; i <= maxdiv; i = _next_div(table, i, flags)) {
+ if (!_is_valid_div(table, i, flags))
continue;
if (rate * i == parent_rate_saved) {
/*
@@ -294,7 +315,7 @@ static int clk_divider_bestdiv(struct clk_hw *hw, unsigned long rate,
parent_rate = __clk_round_rate(__clk_get_parent(hw->clk),
MULT_ROUND_UP(rate, i));
now = DIV_ROUND_UP(parent_rate, i);
- if (_is_best_div(divider, rate, now, best)) {
+ if (_is_best_div(rate, now, best, flags)) {
bestdiv = i;
best = now;
*best_parent_rate = parent_rate;
@@ -302,48 +323,70 @@ static int clk_divider_bestdiv(struct clk_hw *hw, unsigned long rate,
}

if (!bestdiv) {
- bestdiv = _get_maxdiv(divider);
+ bestdiv = _get_maxdiv(table, width, flags);
*best_parent_rate = __clk_round_rate(__clk_get_parent(hw->clk), 1);
}

return bestdiv;
}

-static long clk_divider_round_rate(struct clk_hw *hw, unsigned long rate,
- unsigned long *prate)
+long divider_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *prate, const struct clk_div_table *table,
+ u8 width, unsigned long flags)
{
int div;
- div = clk_divider_bestdiv(hw, rate, prate);
+
+ div = clk_divider_bestdiv(hw, rate, prate, table, width, flags);

return DIV_ROUND_UP(*prate, div);
}
+EXPORT_SYMBOL_GPL(divider_round_rate);

-static int clk_divider_set_rate(struct clk_hw *hw, unsigned long rate,
- unsigned long parent_rate)
+static long clk_divider_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *prate)
{
struct clk_divider *divider = to_clk_divider(hw);
+
+ return divider_round_rate(hw, rate, prate, divider->table,
+ divider->width, divider->flags);
+}
+
+int divider_get_val(unsigned long rate, unsigned long parent_rate,
+ const struct clk_div_table *table, u8 width,
+ unsigned long flags)
+{
unsigned int div, value;
- unsigned long flags = 0;
- u32 val;

div = DIV_ROUND_UP(parent_rate, rate);

- if (!_is_valid_div(divider, div))
+ if (!_is_valid_div(table, div, flags))
return -EINVAL;

- value = _get_val(divider, div);
+ value = _get_val(table, div, flags);
+
+ return min_t(unsigned int, value, div_mask(width));
+}
+EXPORT_SYMBOL_GPL(divider_get_val);
+
+static int clk_divider_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct clk_divider *divider = to_clk_divider(hw);
+ unsigned int value;
+ unsigned long flags = 0;
+ u32 val;

- if (value > div_mask(divider))
- value = div_mask(divider);
+ value = divider_get_val(rate, parent_rate, divider->table,
+ divider->width, divider->flags);

if (divider->lock)
spin_lock_irqsave(divider->lock, flags);

if (divider->flags & CLK_DIVIDER_HIWORD_MASK) {
- val = div_mask(divider) << (divider->shift + 16);
+ val = div_mask(divider->width) << (divider->shift + 16);
} else {
val = clk_readl(divider->reg);
- val &= ~(div_mask(divider) << divider->shift);
+ val &= ~(div_mask(divider->width) << divider->shift);
}
val |= value << divider->shift;
clk_writel(val, divider->reg);
diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
index 446faed3f79f..6e7b3a431b20 100644
--- a/include/linux/clk-provider.h
+++ b/include/linux/clk-provider.h
@@ -353,6 +353,17 @@ struct clk_divider {

extern const struct clk_ops clk_divider_ops;
extern const struct clk_ops clk_divider_ro_ops;
+
+unsigned long divider_recalc_rate(struct clk_hw *hw, unsigned long parent_rate,
+ unsigned int val, const struct clk_div_table *table,
+ unsigned long flags);
+long divider_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *prate, const struct clk_div_table *table,
+ u8 width, unsigned long flags);
+int divider_get_val(unsigned long rate, unsigned long parent_rate,
+ const struct clk_div_table *table, u8 width,
+ unsigned long flags);
+
struct clk *clk_register_divider(struct device *dev, const char *name,
const char *parent_name, unsigned long flags,
void __iomem *reg, u8 shift, u8 width,
--
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a Linux Foundation Collaborative Project

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Next message: Stephen Boyd: "[PATCH 3/7] clk: qcom: Add support for cdiv clocks"
Previous message: Stephen Boyd: "[PATCH 4/7] clk: qcom: Add simple regmap based muxes"
In reply to: Stephen Boyd: "[PATCH 4/7] clk: qcom: Add simple regmap based muxes"
Next in thread: Stephen Boyd: "[PATCH 3/7] clk: qcom: Add support for cdiv clocks"
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