diff options
Diffstat (limited to 'drivers/clk/clk-divider.c')
| -rw-r--r-- | drivers/clk/clk-divider.c | 189 |
1 files changed, 155 insertions, 34 deletions
diff --git a/drivers/clk/clk-divider.c b/drivers/clk/clk-divider.c index 8ea11b44452..a9204c69148 100644 --- a/drivers/clk/clk-divider.c +++ b/drivers/clk/clk-divider.c @@ -30,18 +30,89 @@ #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_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; +} 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; } @@ -52,6 +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) { @@ -62,10 +153,7 @@ 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 +170,8 @@ static int clk_divider_bestdiv(struct clk_hw *hw, unsigned long rate, maxdiv = min(ULONG_MAX / rate, maxdiv); for (i = 1; i <= maxdiv; i++) { + if (!_is_valid_div(divider, i)) + continue; parent_rate = __clk_round_rate(__clk_get_parent(hw->clk), MULT_ROUND_UP(rate, i)); now = parent_rate / i; @@ -93,9 +183,7 @@ 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 +203,22 @@ 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) @@ -148,22 +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; @@ -178,7 +253,7 @@ struct clk *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); @@ -189,6 +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); @@ -198,3 +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); +} |