Some of clocks can have a limit on minimum divider value that can be
programmed, prepare for such a support.
Add a new field min_div for the basic divider clock and a new dynamic
clock divider registration function where minimum divider value can
be specified. Keep behaviour of existing divider clock registration
functions, static initialization helpers as was earlier.
Signed-off-by: Afzal Mohammed <afzal@xxxxxx>
---
v2: create a new registration function for those that needs to
constrain minimum divider value instead of modifying existing
registration functions and hence remove modification in other
clock files.
drivers/clk/clk-divider.c | 37 ++++++++++++++++++++++++++++++++++---
include/linux/clk-private.h | 6 +++++-
include/linux/clk-provider.h | 7 +++++++
3 files changed, 46 insertions(+), 4 deletions(-)
diff --git a/drivers/clk/clk-divider.c b/drivers/clk/clk-divider.c
index a9204c6..4025c5a 100644
--- a/drivers/clk/clk-divider.c
+++ b/drivers/clk/clk-divider.c
@@ -236,7 +236,7 @@ EXPORT_SYMBOL_GPL(clk_divider_ops);
static struct clk *_register_divider(struct device *dev, const char *name,
const char *parent_name, unsigned long flags,
- void __iomem *reg, u8 shift, u8 width,
+ void __iomem *reg, u8 shift, u8 width, u8 min_div,
u8 clk_divider_flags, const struct clk_div_table *table,
spinlock_t *lock)
{
@@ -244,6 +244,11 @@ static struct clk *_register_divider(struct device *dev, const char *name,
struct clk *clk;
struct clk_init_data init;
+ if (!min_div) {
+ pr_err("%s: minimum divider cannot be zero\n", __func__);
+ return ERR_PTR(-EINVAL);
+ }
+
/* allocate the divider */
div = kzalloc(sizeof(struct clk_divider), GFP_KERNEL);
if (!div) {
@@ -261,6 +266,7 @@ static struct clk *_register_divider(struct device *dev, const char *name,
div->reg = reg;
div->shift = shift;
div->width = width;
+ div->min_div = min_div;
div->flags = clk_divider_flags;
div->lock = lock;
div->hw.init = &init;
@@ -276,6 +282,29 @@ static struct clk *_register_divider(struct device *dev, const char *name,
}
/**
+ * clk_register_min_divider - register a divider clock having minimum divider
+ * constraints with clock framework
+ * @dev: device registering this clock
+ * @name: name of this clock
+ * @parent_name: name of clock's parent
+ * @flags: framework-specific flags
+ * @reg: register address to adjust divider
+ * @shift: number of bits to shift the bitfield
+ * @width: width of the bitfield
+ * @min_div: minimum allowable divider
+ * @clk_divider_flags: divider-specific flags for this clock
+ * @lock: shared register lock for this clock
+ */
+struct clk *clk_register_min_divider(struct device *dev, const char *name,
+ const char *parent_name, unsigned long flags,
+ void __iomem *reg, u8 shift, u8 width, u8 min_div,
+ u8 clk_divider_flags, spinlock_t *lock)
+{
+ return _register_divider(dev, name, parent_name, flags, reg, shift,
+ width, min_div, clk_divider_flags, NULL, lock);
+}
+
+/**
* clk_register_divider - register a divider clock with the clock framework
* @dev: device registering this clock
* @name: name of this clock
@@ -293,7 +322,8 @@ struct clk *clk_register_divider(struct device *dev, const char *name,
u8 clk_divider_flags, spinlock_t *lock)
{
return _register_divider(dev, name, parent_name, flags, reg, shift,
- width, clk_divider_flags, NULL, lock);
+ width, CLK_DIVIDER_MIN_DIV_DEFAULT, clk_divider_flags,
+ NULL, lock);
}
/**
@@ -317,5 +347,6 @@ struct clk *clk_register_divider_table(struct device *dev, const char *name,
spinlock_t *lock)
{
return _register_divider(dev, name, parent_name, flags, reg, shift,
- width, clk_divider_flags, table, lock);
+ width, CLK_DIVIDER_MIN_DIV_DEFAULT, clk_divider_flags,
+ table, lock);
}
diff --git a/include/linux/clk-private.h b/include/linux/clk-private.h
index 9c7f580..942a1be 100644
--- a/include/linux/clk-private.h
+++ b/include/linux/clk-private.h
@@ -105,7 +105,8 @@ struct clk {
#define _DEFINE_CLK_DIVIDER(_name, _parent_name, _parent_ptr, \
_flags, _reg, _shift, _width, \
- _divider_flags, _table, _lock) \
+ _min_div, _divider_flags, \
+ _table, _lock) \
static struct clk _name; \
static const char *_name##_parent_names[] = { \
_parent_name, \
@@ -120,6 +121,7 @@ struct clk {
.reg = _reg, \
.shift = _shift, \
.width = _width, \
+ .min_div = _min_div, \
.flags = _divider_flags, \
.table = _table, \
.lock = _lock, \
@@ -132,6 +134,7 @@ struct clk {
_divider_flags, _lock) \
_DEFINE_CLK_DIVIDER(_name, _parent_name, _parent_ptr, \
_flags, _reg, _shift, _width, \
+ CLK_DIVIDER_MIN_DIV_DEFAULT, \
_divider_flags, NULL, _lock)
#define DEFINE_CLK_DIVIDER_TABLE(_name, _parent_name, \
@@ -140,6 +143,7 @@ struct clk {
_table, _lock) \
_DEFINE_CLK_DIVIDER(_name, _parent_name, _parent_ptr, \
_flags, _reg, _shift, _width, \
+ CLK_DIVIDER_MIN_DIV_DEFAULT, \
_divider_flags, _table, _lock) \
#define DEFINE_CLK_MUX(_name, _parent_names, _parents, _flags, \
diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
index 4989b8a..1c09481 100644
--- a/include/linux/clk-provider.h
+++ b/include/linux/clk-provider.h
@@ -248,15 +248,22 @@ struct clk_divider {
void __iomem *reg;
u8 shift;
u8 width;
+ u8 min_div;
u8 flags;
const struct clk_div_table *table;
spinlock_t *lock;
};
+#define CLK_DIVIDER_MIN_DIV_DEFAULT 1
+
#define CLK_DIVIDER_ONE_BASED BIT(0)
#define CLK_DIVIDER_POWER_OF_TWO BIT(1)
extern const struct clk_ops clk_divider_ops;
+struct clk *clk_register_min_divider(struct device *dev, const char *name,
+ const char *parent_name, unsigned long flags,
+ void __iomem *reg, u8 shift, u8 width, u8 min_div,
+ u8 clk_divider_flags, spinlock_t *lock);
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,
--
1.7.12
--
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