From 6d9252bd9a4bb1dadc1f199fd276e3464a251085 Mon Sep 17 00:00:00 2001 From: Rajendra Nayak Date: Thu, 17 May 2012 15:52:13 +0530 Subject: clk: Add support for power of two type dividers Quite often dividers and the value programmed in the register have a relation of 'power of two', something like value div 0 1 1 2 2 4 3 8... Add support for such dividers as part of clk-divider. The clk-divider flag 'CLK_DIVIDER_POWER_OF_TWO' should be used to define such clocks. Signed-off-by: Rajendra Nayak Signed-off-by: Mike Turquette --- drivers/clk/clk-divider.c | 66 +++++++++++++++++++++++++++++++++-------------- 1 file changed, 47 insertions(+), 19 deletions(-) (limited to 'drivers/clk/clk-divider.c') diff --git a/drivers/clk/clk-divider.c b/drivers/clk/clk-divider.c index 8ea11b44452..e548c4328f3 100644 --- a/drivers/clk/clk-divider.c +++ b/drivers/clk/clk-divider.c @@ -30,18 +30,50 @@ #define to_clk_divider(_hw) container_of(_hw, struct clk_divider, hw) #define div_mask(d) ((1 << (d->width)) - 1) +#define is_power_of_two(i) !(i & ~i) + +static unsigned int _get_maxdiv(struct clk_divider *divider) +{ + if (divider->flags & CLK_DIVIDER_ONE_BASED) + return div_mask(divider); + if (divider->flags & CLK_DIVIDER_POWER_OF_TWO) + return 1 << div_mask(divider); + return div_mask(divider) + 1; +} + +static unsigned int _get_div(struct clk_divider *divider, unsigned int val) +{ + if (divider->flags & CLK_DIVIDER_ONE_BASED) + return val; + if (divider->flags & CLK_DIVIDER_POWER_OF_TWO) + return 1 << val; + return val + 1; +} + +static unsigned int _get_val(struct clk_divider *divider, u8 div) +{ + if (divider->flags & CLK_DIVIDER_ONE_BASED) + return div; + if (divider->flags & CLK_DIVIDER_POWER_OF_TWO) + return __ffs(div); + return div - 1; +} 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 div; + unsigned int div, val; - div = readl(divider->reg) >> divider->shift; - div &= div_mask(divider); + val = readl(divider->reg) >> divider->shift; + val &= div_mask(divider); - if (!(divider->flags & CLK_DIVIDER_ONE_BASED)) - div++; + div = _get_div(divider, val); + if (!div) { + WARN(1, "%s: Invalid divisor for clock %s\n", __func__, + __clk_get_name(hw->clk)); + return parent_rate; + } return parent_rate / div; } @@ -62,10 +94,7 @@ static int clk_divider_bestdiv(struct clk_hw *hw, unsigned long rate, if (!rate) rate = 1; - maxdiv = (1 << divider->width); - - if (divider->flags & CLK_DIVIDER_ONE_BASED) - maxdiv--; + maxdiv = _get_maxdiv(divider); if (!(__clk_get_flags(hw->clk) & CLK_SET_RATE_PARENT)) { parent_rate = *best_parent_rate; @@ -82,6 +111,9 @@ static int clk_divider_bestdiv(struct clk_hw *hw, unsigned long rate, maxdiv = min(ULONG_MAX / rate, maxdiv); for (i = 1; i <= maxdiv; i++) { + if ((divider->flags & CLK_DIVIDER_POWER_OF_TWO) + && (!is_power_of_two(i))) + continue; parent_rate = __clk_round_rate(__clk_get_parent(hw->clk), MULT_ROUND_UP(rate, i)); now = parent_rate / i; @@ -93,9 +125,7 @@ static int clk_divider_bestdiv(struct clk_hw *hw, unsigned long rate, } if (!bestdiv) { - bestdiv = (1 << divider->width); - if (divider->flags & CLK_DIVIDER_ONE_BASED) - bestdiv--; + bestdiv = _get_maxdiv(divider); *best_parent_rate = __clk_round_rate(__clk_get_parent(hw->clk), 1); } @@ -115,24 +145,22 @@ 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 div; + unsigned int div, value; unsigned long flags = 0; u32 val; div = parent_rate / rate; + value = _get_val(divider, div); - if (!(divider->flags & CLK_DIVIDER_ONE_BASED)) - div--; - - if (div > div_mask(divider)) - div = div_mask(divider); + if (value > div_mask(divider)) + value = div_mask(divider); if (divider->lock) spin_lock_irqsave(divider->lock, flags); val = readl(divider->reg); val &= ~(div_mask(divider) << divider->shift); - val |= div << divider->shift; + val |= value << divider->shift; writel(val, divider->reg); if (divider->lock) -- cgit v1.2.3-70-g09d2 From 357c3f0a6c7613f7230fcaf1eb16190ed2a4b0af Mon Sep 17 00:00:00 2001 From: Rajendra Nayak Date: Fri, 29 Jun 2012 19:06:32 +0530 Subject: clk: Add support for rate table based dividers Some divider clks do not have any obvious relationship between the divider and the value programmed in the register. For instance, say a value of 1 could signify divide by 6 and a value of 2 could signify divide by 4 etc. Also there are dividers where not all values possible based on the bitfield width are valid. For instance a 3 bit wide bitfield can be used to program a value from 0 to 7. However its possible that only 0 to 4 are valid values. All these cases need the platform code to pass a simple table of divider/value tuple, so the framework knows the exact value to be written based on the divider calculation and can also do better error checking. This patch adds support for such rate table based dividers and as part of the support adds a new registration function 'clk_register_divider_table()' and a new macro for static definition 'DEFINE_CLK_DIVIDER_TABLE'. Signed-off-by: Rajendra Nayak Signed-off-by: Mike Turquette --- drivers/clk/clk-divider.c | 125 +++++++++++++++++++++++++++++++++++++------ include/linux/clk-private.h | 20 ++++++- include/linux/clk-provider.h | 12 +++++ 3 files changed, 139 insertions(+), 18 deletions(-) (limited to 'drivers/clk/clk-divider.c') diff --git a/drivers/clk/clk-divider.c b/drivers/clk/clk-divider.c index e548c4328f3..02a4da98176 100644 --- a/drivers/clk/clk-divider.c +++ b/drivers/clk/clk-divider.c @@ -32,30 +32,69 @@ #define div_mask(d) ((1 << (d->width)) - 1) #define is_power_of_two(i) !(i & ~i) +static unsigned int _get_table_maxdiv(const struct clk_div_table *table) +{ + unsigned int maxdiv = 0; + const struct clk_div_table *clkt; + + for (clkt = table; clkt->div; clkt++) + if (clkt->div > maxdiv) + maxdiv = clkt->div; + return maxdiv; +} + static unsigned int _get_maxdiv(struct clk_divider *divider) { 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; } +static unsigned int _get_table_div(const struct clk_div_table *table, + unsigned int val) +{ + const struct clk_div_table *clkt; + + for (clkt = table; clkt->div; clkt++) + if (clkt->val == val) + return clkt->div; + return 0; +} + static unsigned int _get_div(struct clk_divider *divider, unsigned int val) { if (divider->flags & CLK_DIVIDER_ONE_BASED) return val; if (divider->flags & CLK_DIVIDER_POWER_OF_TWO) return 1 << val; + if (divider->table) + return _get_table_div(divider->table, val); return val + 1; } +static unsigned int _get_table_val(const struct clk_div_table *table, + unsigned int div) +{ + const struct clk_div_table *clkt; + + for (clkt = table; clkt->div; clkt++) + if (clkt->div == div) + return clkt->val; + return 0; +} + static unsigned int _get_val(struct clk_divider *divider, u8 div) { if (divider->flags & CLK_DIVIDER_ONE_BASED) return div; if (divider->flags & CLK_DIVIDER_POWER_OF_TWO) return __ffs(div); + if (divider->table) + return _get_table_val(divider->table, div); return div - 1; } @@ -84,6 +123,26 @@ static unsigned long clk_divider_recalc_rate(struct clk_hw *hw, */ #define MULT_ROUND_UP(r, m) ((r) * (m) + (m) - 1) +static bool _is_valid_table_div(const struct clk_div_table *table, + unsigned int div) +{ + const struct clk_div_table *clkt; + + for (clkt = table; clkt->div; clkt++) + if (clkt->div == div) + return true; + return false; +} + +static bool _is_valid_div(struct clk_divider *divider, unsigned int div) +{ + if (divider->flags & CLK_DIVIDER_POWER_OF_TWO) + return is_power_of_two(div); + if (divider->table) + return _is_valid_table_div(divider->table, div); + return true; +} + static int clk_divider_bestdiv(struct clk_hw *hw, unsigned long rate, unsigned long *best_parent_rate) { @@ -111,8 +170,7 @@ static int clk_divider_bestdiv(struct clk_hw *hw, unsigned long rate, maxdiv = min(ULONG_MAX / rate, maxdiv); for (i = 1; i <= maxdiv; i++) { - if ((divider->flags & CLK_DIVIDER_POWER_OF_TWO) - && (!is_power_of_two(i))) + if (!_is_valid_div(divider, i)) continue; parent_rate = __clk_round_rate(__clk_get_parent(hw->clk), MULT_ROUND_UP(rate, i)); @@ -176,22 +234,11 @@ const struct clk_ops clk_divider_ops = { }; EXPORT_SYMBOL_GPL(clk_divider_ops); -/** - * clk_register_divider - register a divider clock with the 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 - * @clk_divider_flags: divider-specific flags for this clock - * @lock: shared register lock for this clock - */ -struct clk *clk_register_divider(struct device *dev, const char *name, +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, - u8 clk_divider_flags, spinlock_t *lock) + u8 clk_divider_flags, const struct clk_div_table *table, + spinlock_t *lock) { struct clk_divider *div; struct clk *clk; @@ -217,6 +264,7 @@ struct clk *clk_register_divider(struct device *dev, const char *name, div->flags = clk_divider_flags; div->lock = lock; div->hw.init = &init; + div->table = table; /* register the clock */ clk = clk_register(dev, &div->hw); @@ -226,3 +274,48 @@ struct clk *clk_register_divider(struct device *dev, const char *name, return clk; } + +/** + * clk_register_divider - register a divider clock with the 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 + * @clk_divider_flags: divider-specific flags for this clock + * @lock: shared register lock for this clock + */ +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, + u8 clk_divider_flags, spinlock_t *lock) +{ + return _register_divider(dev, name, parent_name, flags, reg, shift, + width, clk_divider_flags, NULL, lock); +} + +/** + * clk_register_divider_table - register a table based divider clock with + * the 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 + * @clk_divider_flags: divider-specific flags for this clock + * @table: array of divider/value pairs ending with a div set to 0 + * @lock: shared register lock for this clock + */ +struct clk *clk_register_divider_table(struct device *dev, const char *name, + const char *parent_name, unsigned long flags, + void __iomem *reg, u8 shift, u8 width, + u8 clk_divider_flags, const struct clk_div_table *table, + spinlock_t *lock) +{ + return _register_divider(dev, name, parent_name, flags, reg, shift, + width, clk_divider_flags, table, lock); +} diff --git a/include/linux/clk-private.h b/include/linux/clk-private.h index eb3f84bc532..cc9972d1429 100644 --- a/include/linux/clk-private.h +++ b/include/linux/clk-private.h @@ -103,9 +103,9 @@ struct clk { DEFINE_CLK(_name, clk_gate_ops, _flags, \ _name##_parent_names, _name##_parents); -#define DEFINE_CLK_DIVIDER(_name, _parent_name, _parent_ptr, \ +#define _DEFINE_CLK_DIVIDER(_name, _parent_name, _parent_ptr, \ _flags, _reg, _shift, _width, \ - _divider_flags, _lock) \ + _divider_flags, _table, _lock) \ static struct clk _name; \ static const char *_name##_parent_names[] = { \ _parent_name, \ @@ -121,11 +121,27 @@ struct clk { .shift = _shift, \ .width = _width, \ .flags = _divider_flags, \ + .table = _table, \ .lock = _lock, \ }; \ DEFINE_CLK(_name, clk_divider_ops, _flags, \ _name##_parent_names, _name##_parents); +#define DEFINE_CLK_DIVIDER(_name, _parent_name, _parent_ptr, \ + _flags, _reg, _shift, _width, \ + _divider_flags, _lock) \ + _DEFINE_CLK_DIVIDER(_name, _parent_name, _parent_ptr, \ + _flags, _reg, _shift, _width, \ + _divider_flags, NULL, _lock) + +#define DEFINE_CLK_DIVIDER_TABLE(_name, _parent_name, \ + _parent_ptr, _flags, _reg, \ + _shift, _width, _divider_flags, \ + _table, _lock) \ + _DEFINE_CLK_DIVIDER(_name, _parent_name, _parent_ptr, \ + _flags, _reg, _shift, _width, \ + _divider_flags, _table, _lock) \ + #define DEFINE_CLK_MUX(_name, _parent_names, _parents, _flags, \ _reg, _shift, _width, \ _mux_flags, _lock) \ diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h index 4a0b483986c..79caee9f148 100644 --- a/include/linux/clk-provider.h +++ b/include/linux/clk-provider.h @@ -203,6 +203,11 @@ struct clk *clk_register_gate(struct device *dev, const char *name, void __iomem *reg, u8 bit_idx, u8 clk_gate_flags, spinlock_t *lock); +struct clk_div_table { + unsigned int val; + unsigned int div; +}; + /** * struct clk_divider - adjustable divider clock * @@ -210,6 +215,7 @@ struct clk *clk_register_gate(struct device *dev, const char *name, * @reg: register containing the divider * @shift: shift to the divider bit field * @width: width of the divider bit field + * @table: array of value/divider pairs, last entry should have div = 0 * @lock: register lock * * Clock with an adjustable divider affecting its output frequency. Implements @@ -229,6 +235,7 @@ struct clk_divider { u8 shift; u8 width; u8 flags; + const struct clk_div_table *table; spinlock_t *lock; }; @@ -240,6 +247,11 @@ 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, u8 clk_divider_flags, spinlock_t *lock); +struct clk *clk_register_divider_table(struct device *dev, const char *name, + const char *parent_name, unsigned long flags, + void __iomem *reg, u8 shift, u8 width, + u8 clk_divider_flags, const struct clk_div_table *table, + spinlock_t *lock); /** * struct clk_mux - multiplexer clock -- cgit v1.2.3-70-g09d2 From f7d8caadfd2813cbada82ce9041b13c38e8e5282 Mon Sep 17 00:00:00 2001 From: Rajendra Nayak Date: Fri, 1 Jun 2012 14:02:47 +0530 Subject: clk: Add CLK_IS_BASIC flag to identify basic clocks Most platforms end up using a mix of basic clock types and some which use clk_hw_foo struct for filling in custom platform information when the clocks don't fit into basic types supported. In platform code, its useful to know if a clock is using a basic type or clk_hw_foo, which helps platforms know if they can safely use to_clk_hw_foo to derive the clk_hw_foo pointer from clk_hw. Mark all basic clocks with a CLK_IS_BASIC flag. Signed-off-by: Rajendra Nayak Signed-off-by: Mike Turquette --- drivers/clk/clk-divider.c | 2 +- drivers/clk/clk-fixed-factor.c | 2 +- drivers/clk/clk-fixed-rate.c | 2 +- drivers/clk/clk-gate.c | 2 +- drivers/clk/clk-mux.c | 2 +- include/linux/clk-private.h | 2 +- include/linux/clk-provider.h | 1 + 7 files changed, 7 insertions(+), 6 deletions(-) (limited to 'drivers/clk/clk-divider.c') diff --git a/drivers/clk/clk-divider.c b/drivers/clk/clk-divider.c index 02a4da98176..a9204c69148 100644 --- a/drivers/clk/clk-divider.c +++ b/drivers/clk/clk-divider.c @@ -253,7 +253,7 @@ static struct clk *_register_divider(struct device *dev, const char *name, init.name = name; init.ops = &clk_divider_ops; - init.flags = flags; + init.flags = flags | CLK_IS_BASIC; init.parent_names = (parent_name ? &parent_name: NULL); init.num_parents = (parent_name ? 1 : 0); diff --git a/drivers/clk/clk-fixed-factor.c b/drivers/clk/clk-fixed-factor.c index c8c003e217a..a4899855c0f 100644 --- a/drivers/clk/clk-fixed-factor.c +++ b/drivers/clk/clk-fixed-factor.c @@ -82,7 +82,7 @@ struct clk *clk_register_fixed_factor(struct device *dev, const char *name, init.name = name; init.ops = &clk_fixed_factor_ops; - init.flags = flags; + init.flags = flags | CLK_IS_BASIC; init.parent_names = &parent_name; init.num_parents = 1; diff --git a/drivers/clk/clk-fixed-rate.c b/drivers/clk/clk-fixed-rate.c index cbd24622978..7e146456972 100644 --- a/drivers/clk/clk-fixed-rate.c +++ b/drivers/clk/clk-fixed-rate.c @@ -63,7 +63,7 @@ struct clk *clk_register_fixed_rate(struct device *dev, const char *name, init.name = name; init.ops = &clk_fixed_rate_ops; - init.flags = flags; + init.flags = flags | CLK_IS_BASIC; init.parent_names = (parent_name ? &parent_name: NULL); init.num_parents = (parent_name ? 1 : 0); diff --git a/drivers/clk/clk-gate.c b/drivers/clk/clk-gate.c index 578465e04be..15114febfd9 100644 --- a/drivers/clk/clk-gate.c +++ b/drivers/clk/clk-gate.c @@ -130,7 +130,7 @@ struct clk *clk_register_gate(struct device *dev, const char *name, init.name = name; init.ops = &clk_gate_ops; - init.flags = flags; + init.flags = flags | CLK_IS_BASIC; init.parent_names = (parent_name ? &parent_name: NULL); init.num_parents = (parent_name ? 1 : 0); diff --git a/drivers/clk/clk-mux.c b/drivers/clk/clk-mux.c index fd36a8ea73d..508c032edce 100644 --- a/drivers/clk/clk-mux.c +++ b/drivers/clk/clk-mux.c @@ -106,7 +106,7 @@ struct clk *clk_register_mux(struct device *dev, const char *name, init.name = name; init.ops = &clk_mux_ops; - init.flags = flags; + init.flags = flags | CLK_IS_BASIC; init.parent_names = parent_names; init.num_parents = num_parents; diff --git a/include/linux/clk-private.h b/include/linux/clk-private.h index cc9972d1429..9c7f5807824 100644 --- a/include/linux/clk-private.h +++ b/include/linux/clk-private.h @@ -64,7 +64,7 @@ struct clk { .parent_names = _parent_names, \ .num_parents = ARRAY_SIZE(_parent_names), \ .parents = _parents, \ - .flags = _flags, \ + .flags = _flags | CLK_IS_BASIC, \ } #define DEFINE_CLK_FIXED_RATE(_name, _flags, _rate, \ diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h index 79caee9f148..0236f58f3e6 100644 --- a/include/linux/clk-provider.h +++ b/include/linux/clk-provider.h @@ -25,6 +25,7 @@ #define CLK_SET_RATE_PARENT BIT(2) /* propagate rate change up one level */ #define CLK_IGNORE_UNUSED BIT(3) /* do not gate even if unused */ #define CLK_IS_ROOT BIT(4) /* root clk, has no parent */ +#define CLK_IS_BASIC BIT(5) /* Basic clk, can't do a to_clk_foo() */ struct clk_hw; -- cgit v1.2.3-70-g09d2