[PATCH RFC 2/3] clk/i2c-div: Allow custom divider accessors

From: Soren Brinkmann
Date: Fri Feb 28 2014 - 18:35:35 EST


Allow to provide custom accessors to read/write the divider from/to HW
since some I2C dividers spread dividers across multiple registers.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xxxxxxxxxx>
---
drivers/clk/clk-i2c-divider.c | 64 ++++++++++++++++++++++++++++++++-----------
include/linux/clk-provider.h | 15 ++++++++--
2 files changed, 60 insertions(+), 19 deletions(-)

diff --git a/drivers/clk/clk-i2c-divider.c b/drivers/clk/clk-i2c-divider.c
index 690eae191072..086fb7935ccb 100644
--- a/drivers/clk/clk-i2c-divider.c
+++ b/drivers/clk/clk-i2c-divider.c
@@ -99,14 +99,23 @@ static unsigned int _get_val(struct clk_i2c_divider *divider, u8 div)
return div - 1;
}

+static unsigned int clk_i2c_divider_get_div(struct clk_i2c_divider *divider)
+{
+ unsigned int div;
+
+ div = clk_i2c_readb(divider->regmap, divider->reg) >> divider->shift;
+ div &= div_mask(divider);
+
+ return div;
+}
+
static unsigned long clk_divider_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct clk_i2c_divider *divider = to_clk_i2c_divider(hw);
unsigned int div, val;

- val = clk_i2c_readb(divider->regmap, divider->reg) >> divider->shift;
- val &= div_mask(divider);
+ val = divider->get_div(divider);

div = _get_div(divider, val);
if (!div) {
@@ -211,16 +220,10 @@ static long clk_divider_round_rate(struct clk_hw *hw, unsigned long rate,
return *prate / div;
}

-static int clk_divider_set_rate(struct clk_hw *hw, unsigned long rate,
- unsigned long parent_rate)
+static int clk_i2c_divider_set_div(unsigned int value,
+ struct clk_i2c_divider *divider)
{
- struct clk_i2c_divider *divider = to_clk_i2c_divider(hw);
- unsigned int div, value;
- unsigned long flags = 0;
- u32 val;
-
- div = parent_rate / rate;
- value = _get_val(divider, div);
+ unsigned int val;

if (value > div_mask(divider))
value = div_mask(divider);
@@ -237,6 +240,18 @@ static int clk_divider_set_rate(struct clk_hw *hw, unsigned long rate,
return 0;
}

+static int clk_divider_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct clk_i2c_divider *divider = to_clk_i2c_divider(hw);
+ unsigned int div, value;
+
+ div = parent_rate / rate;
+ value = _get_val(divider, div);
+
+ return divider->set_div(value, divider);
+}
+
const struct clk_ops clk_i2c_divider_ops = {
.recalc_rate = clk_divider_recalc_rate,
.round_rate = clk_divider_round_rate,
@@ -247,7 +262,9 @@ EXPORT_SYMBOL_GPL(clk_i2c_divider_ops);
static struct clk *_register_divider(struct device *dev, const char *name,
const char *parent_name, unsigned long flags,
struct regmap *regmap, unsigned int reg, u8 shift, u8 width,
- u8 clk_divider_flags, const struct clk_div_table *table)
+ u8 clk_divider_flags, const struct clk_div_table *table,
+ unsigned int (*get_div)(struct clk_i2c_divider *),
+ int (*set_div)(unsigned int val, struct clk_i2c_divider *))
{
struct clk_i2c_divider *div;
struct clk *clk;
@@ -286,6 +303,15 @@ static struct clk *_register_divider(struct device *dev, const char *name,
div->flags = clk_divider_flags;
div->hw.init = &init;
div->table = table;
+ if (get_div)
+ div->get_div = get_div;
+ else
+ div->get_div = clk_i2c_divider_get_div;
+
+ if (set_div)
+ div->set_div = set_div;
+ else
+ div->set_div = clk_i2c_divider_set_div;

/* register the clock */
clk = devm_clk_register(dev, &div->hw);
@@ -311,10 +337,13 @@ static struct clk *_register_divider(struct device *dev, const char *name,
struct clk *clk_i2c_register_divider(struct device *dev, const char *name,
const char *parent_name, unsigned long flags,
struct regmap *regmap, unsigned int reg, u8 shift, u8 width,
- u8 clk_divider_flags)
+ u8 clk_divider_flags,
+ unsigned int (*get_div)(struct clk_i2c_divider *),
+ int (*set_div)(unsigned int val, struct clk_i2c_divider *))
{
return _register_divider(dev, name, parent_name, flags, regmap, reg,
- shift, width, clk_divider_flags, NULL);
+ shift, width, clk_divider_flags, NULL, get_div,
+ set_div);
}
EXPORT_SYMBOL_GPL(clk_i2c_register_divider);

@@ -335,9 +364,12 @@ EXPORT_SYMBOL_GPL(clk_i2c_register_divider);
struct clk *clk_i2c_register_divider_table(struct device *dev, const char *name,
const char *parent_name, unsigned long flags,
struct regmap *regmap, unsigned int reg, u8 shift, u8 width,
- u8 clk_divider_flags, const struct clk_div_table *table)
+ u8 clk_divider_flags, const struct clk_div_table *table,
+ unsigned int (*get_div)(struct clk_i2c_divider *),
+ int (*set_div)(unsigned int val, struct clk_i2c_divider *))
{
return _register_divider(dev, name, parent_name, flags, regmap, reg,
- shift, width, clk_divider_flags, table);
+ shift, width, clk_divider_flags, table, get_div,
+ set_div);
}
EXPORT_SYMBOL_GPL(clk_i2c_register_divider_table);
diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
index d86bb6ec4232..bccb711b0ea1 100644
--- a/include/linux/clk-provider.h
+++ b/include/linux/clk-provider.h
@@ -353,6 +353,8 @@ struct clk_i2c_divider {
u8 width;
u8 flags;
const struct clk_div_table *table;
+ unsigned int (*get_div)(struct clk_i2c_divider *);
+ int (*set_div)(unsigned int, struct clk_i2c_divider *);
};

#define CLK_DIVIDER_ONE_BASED BIT(0)
@@ -655,14 +657,21 @@ struct clk *clk_i2c_register_mux_table(struct device *dev, const char *name,
const char **parent_names, u8 num_parents, unsigned long flags,
struct regmap *regmap, unsigned int reg, u8 shift, u32 mask,
u8 clk_mux_flags, u32 *table);
+
struct clk *clk_i2c_register_divider(struct device *dev, const char *name,
const char *parent_name, unsigned long flags,
struct regmap *regmap, unsigned int reg, u8 shift, u8 width,
- u8 clk_divider_flags);
-struct clk *clk_i2c_register_divider_table(struct device *dev, const char *name,
+ u8 clk_divider_flags, unsigned int (*get_div)(struct
+ clk_i2c_divider *), int (*set_div)(unsigned int val,
+ struct clk_i2c_divider *));
+
+struct clk *clk_i2c_register_divider_table(struct device *dev, const char *name,
const char *parent_name, unsigned long flags,
struct regmap *regmap, unsigned int reg, u8 shift, u8 width,
- u8 clk_divider_flags, const struct clk_div_table *table);
+ u8 clk_divider_flags, const struct clk_div_table *table,
+ unsigned int (*get_div)(struct clk_i2c_divider *),
+ int (*set_div)(unsigned int val, struct clk_i2c_divider *));
+
#endif /* CONFIG_COMMON_CLK_I2C */

#endif /* CONFIG_COMMON_CLK */
--
1.9.0.1.g4196000

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