diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2014-06-07 20:27:30 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-06-07 20:27:30 -0700 |
commit | 1a5700bc2d10cd379a795fd2bb377a190af5acd4 (patch) | |
tree | e9f754cbc34020dd23c1d2e3e45fb6890ba7593c /drivers/clk/clk-divider.c | |
parent | a68a7509d3af8ee458d32b2416b0c2aaf2a4a7e3 (diff) | |
parent | 3cbcb16095f916f50a5a55066fcc4be06946ce1e (diff) | |
download | op-kernel-dev-1a5700bc2d10cd379a795fd2bb377a190af5acd4.zip op-kernel-dev-1a5700bc2d10cd379a795fd2bb377a190af5acd4.tar.gz |
Merge tag 'clk-for-linus-3.16' of git://git.linaro.org/people/mike.turquette/linux into next
Pull clock framework updates from Mike Turquette:
"The clock framework changes for 3.16 are pretty typical: mostly clock
driver additions and fixes. There are additions to the clock core
code for some of the basic types (e.g. the common divider type has
some fixes and featured added to it).
One minor annoyance is a last-minute dependency that wasn't handled
quite right. Commit ba0fae3b06a6 ("clk: berlin: add core clock driver
for BG2/BG2CD") in this pull request depends on
include/dt-bindings/clock/berlin2.h, which is already in your tree via
the arm-soc pull request. Building for the berlin platform will break
when the clk tree is built on it's own, but merged into your master
branch everything should be fine"
* tag 'clk-for-linus-3.16' of git://git.linaro.org/people/mike.turquette/linux: (75 commits)
mmc: sunxi: Add driver for SD/MMC hosts found on Allwinner sunxi SoCs
clk: export __clk_round_rate for providers
clk: versatile: free icst on error return
clk: qcom: Return error pointers for unimplemented clocks
clk: qcom: Support msm8974pro global clock control hardware
clk: qcom: Properly support display clocks on msm8974
clk: qcom: Support display RCG clocks
clk: qcom: Return highest rate when round_rate() exceeds plan
clk: qcom: Fix mmcc-8974's PLL configurations
clk: qcom: Fix clk_rcg2_is_enabled() check
clk: berlin: add core clock driver for BG2Q
clk: berlin: add core clock driver for BG2/BG2CD
clk: berlin: add driver for BG2x complex divider cells
clk: berlin: add driver for BG2x simple PLLs
clk: berlin: add driver for BG2x audio/video PLL
clk: st: Terminate of match table
clk/exynos4: Fix compilation warning
ARM: shmobile: r8a7779: Add clock index macros for DT sources
clk: divider: Fix overflow in clk_divider_bestdiv
clk: u300: Terminate of match table
...
Diffstat (limited to 'drivers/clk/clk-divider.c')
-rw-r--r-- | drivers/clk/clk-divider.c | 93 |
1 files changed, 89 insertions, 4 deletions
diff --git a/drivers/clk/clk-divider.c b/drivers/clk/clk-divider.c index 3fbee45..18a9de2 100644 --- a/drivers/clk/clk-divider.c +++ b/drivers/clk/clk-divider.c @@ -43,6 +43,17 @@ static unsigned int _get_table_maxdiv(const struct clk_div_table *table) return maxdiv; } +static unsigned int _get_table_mindiv(const struct clk_div_table *table) +{ + unsigned int mindiv = UINT_MAX; + const struct clk_div_table *clkt; + + for (clkt = table; clkt->div; clkt++) + if (clkt->div < mindiv) + mindiv = clkt->div; + return mindiv; +} + static unsigned int _get_maxdiv(struct clk_divider *divider) { if (divider->flags & CLK_DIVIDER_ONE_BASED) @@ -162,6 +173,24 @@ static int _round_up_table(const struct clk_div_table *table, int div) return up; } +static int _round_down_table(const struct clk_div_table *table, int div) +{ + const struct clk_div_table *clkt; + int down = _get_table_mindiv(table); + + for (clkt = table; clkt->div; clkt++) { + if (clkt->div == div) + return clkt->div; + else if (clkt->div > div) + continue; + + if ((div - clkt->div) < (div - down)) + down = clkt->div; + } + + return down; +} + static int _div_round_up(struct clk_divider *divider, unsigned long parent_rate, unsigned long rate) { @@ -175,6 +204,54 @@ static int _div_round_up(struct clk_divider *divider, return div; } +static int _div_round_closest(struct clk_divider *divider, + unsigned long parent_rate, unsigned long rate) +{ + int up, down, div; + + up = down = div = DIV_ROUND_CLOSEST(parent_rate, rate); + + if (divider->flags & CLK_DIVIDER_POWER_OF_TWO) { + up = __roundup_pow_of_two(div); + down = __rounddown_pow_of_two(div); + } else if (divider->table) { + up = _round_up_table(divider->table, div); + down = _round_down_table(divider->table, div); + } + + return (up - div) <= (div - down) ? up : down; +} + +static int _div_round(struct clk_divider *divider, unsigned long parent_rate, + unsigned long rate) +{ + if (divider->flags & CLK_DIVIDER_ROUND_CLOSEST) + return _div_round_closest(divider, parent_rate, rate); + + return _div_round_up(divider, parent_rate, rate); +} + +static bool _is_best_div(struct clk_divider *divider, + unsigned long rate, unsigned long now, unsigned long best) +{ + if (divider->flags & CLK_DIVIDER_ROUND_CLOSEST) + return abs(rate - now) < abs(rate - best); + + return now <= rate && now > best; +} + +static int _next_div(struct clk_divider *divider, int div) +{ + div++; + + if (divider->flags & CLK_DIVIDER_POWER_OF_TWO) + return __roundup_pow_of_two(div); + if (divider->table) + return _round_up_table(divider->table, div); + + return div; +} + static int clk_divider_bestdiv(struct clk_hw *hw, unsigned long rate, unsigned long *best_parent_rate) { @@ -190,7 +267,7 @@ static int clk_divider_bestdiv(struct clk_hw *hw, unsigned long rate, if (!(__clk_get_flags(hw->clk) & CLK_SET_RATE_PARENT)) { parent_rate = *best_parent_rate; - bestdiv = _div_round_up(divider, parent_rate, rate); + bestdiv = _div_round(divider, parent_rate, rate); bestdiv = bestdiv == 0 ? 1 : bestdiv; bestdiv = bestdiv > maxdiv ? maxdiv : bestdiv; return bestdiv; @@ -202,7 +279,7 @@ static int clk_divider_bestdiv(struct clk_hw *hw, unsigned long rate, */ maxdiv = min(ULONG_MAX / rate, maxdiv); - for (i = 1; i <= maxdiv; i++) { + for (i = 1; i <= maxdiv; i = _next_div(divider, i)) { if (!_is_valid_div(divider, i)) continue; if (rate * i == parent_rate_saved) { @@ -217,7 +294,7 @@ static int clk_divider_bestdiv(struct clk_hw *hw, unsigned long rate, parent_rate = __clk_round_rate(__clk_get_parent(hw->clk), MULT_ROUND_UP(rate, i)); now = DIV_ROUND_UP(parent_rate, i); - if (now <= rate && now > best) { + if (_is_best_div(divider, rate, now, best)) { bestdiv = i; best = now; *best_parent_rate = parent_rate; @@ -284,6 +361,11 @@ const struct clk_ops clk_divider_ops = { }; EXPORT_SYMBOL_GPL(clk_divider_ops); +const struct clk_ops clk_divider_ro_ops = { + .recalc_rate = clk_divider_recalc_rate, +}; +EXPORT_SYMBOL_GPL(clk_divider_ro_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, @@ -309,7 +391,10 @@ static struct clk *_register_divider(struct device *dev, const char *name, } init.name = name; - init.ops = &clk_divider_ops; + if (clk_divider_flags & CLK_DIVIDER_READ_ONLY) + init.ops = &clk_divider_ro_ops; + else + init.ops = &clk_divider_ops; init.flags = flags | CLK_IS_BASIC; init.parent_names = (parent_name ? &parent_name: NULL); init.num_parents = (parent_name ? 1 : 0); |