From da29636d230df4bfee183979d6a924735d1aaa06 Mon Sep 17 00:00:00 2001 From: Afzal Mohammed Date: Thu, 17 Jan 2013 17:11:53 +0530 Subject: [PATCH 06/51] clk: divider: prepare for minimum divider 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 --- 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 5543b7d..da121ac 100644 --- a/drivers/clk/clk-divider.c +++ b/drivers/clk/clk-divider.c @@ -251,7 +251,7 @@ 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) { @@ -266,6 +266,11 @@ static struct clk *_register_divider(struct device *dev, const char *name, } } + 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) { @@ -283,6 +288,7 @@ 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; @@ -298,6 +304,29 @@ 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 @@ -315,7 +344,8 @@ 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); } EXPORT_SYMBOL_GPL(clk_register_divider); @@ -340,6 +370,7 @@ 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); } EXPORT_SYMBOL_GPL(clk_register_divider_table); diff --git a/include/linux/clk-private.h b/include/linux/clk-private.h index 8138c94..c20dd74 100644 --- a/include/linux/clk-private.h +++ b/include/linux/clk-private.h @@ -108,7 +108,8 @@ 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, \ @@ -123,6 +124,7 @@ struct clk { .reg = _reg, \ .shift = _shift, \ .width = _width, \ + .min_div = _min_div, \ .flags = _divider_flags, \ .table = _table, \ .lock = _lock, \ @@ -135,6 +137,7 @@ 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, \ @@ -143,6 +146,7 @@ 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 73bdb69..c44a8e2 100644 --- a/include/linux/clk-provider.h +++ b/include/linux/clk-provider.h @@ -281,17 +281,24 @@ 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) #define CLK_DIVIDER_ALLOW_ZERO BIT(2) #define CLK_DIVIDER_HIWORD_MASK BIT(3) 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, -- 1.7.10.4