diff options
| author | Maxime COQUELIN <maxime.coquelin@st.com> | 2014-01-29 17:24:06 +0100 |
|---|---|---|
| committer | Mike Turquette <mturquette@linaro.org> | 2014-04-30 11:44:00 -0700 |
| commit | dd23c2cd38da2c64af381b19795d2c4f115e8ecb (patch) | |
| tree | 285ce925cb3c9a99720f34b40e42f7e70972d05e /drivers/clk | |
| parent | e813d49d2a477e3b64a9ff32ca7db5737d36cd91 (diff) | |
clk: divider: Fix best div calculation for power-of-two and table dividers
The divider returned by clk_divider_bestdiv() is likely to be invalid in case
of power-of-two and table dividers when CLK_SET_RATE_PARENT flag isn't set.
Fixes boot on STiH416 platform.
Signed-off-by: Maxime Coquelin <maxime.coquelin@st.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
[mturquette@linaro.org: trivial merge conflict & updated changelog]
Diffstat (limited to 'drivers/clk')
| -rw-r--r-- | drivers/clk/clk-divider.c | 37 |
1 files changed, 36 insertions, 1 deletions
diff --git a/drivers/clk/clk-divider.c b/drivers/clk/clk-divider.c index ec22112e569f..4637697c139f 100644 --- a/drivers/clk/clk-divider.c +++ b/drivers/clk/clk-divider.c @@ -144,6 +144,37 @@ static bool _is_valid_div(struct clk_divider *divider, unsigned int div) return true; } +static int _round_up_table(const struct clk_div_table *table, int div) +{ + const struct clk_div_table *clkt; + int up = _get_table_maxdiv(table); + + for (clkt = table; clkt->div; clkt++) { + if (clkt->div == div) + return clkt->div; + else if (clkt->div < div) + continue; + + if ((clkt->div - div) < (up - div)) + up = clkt->div; + } + + return up; +} + +static int _div_round_up(struct clk_divider *divider, + unsigned long parent_rate, unsigned long rate) +{ + int div = DIV_ROUND_UP(parent_rate, rate); + + if (divider->flags & CLK_DIVIDER_POWER_OF_TWO) + div = __roundup_pow_of_two(div); + if (divider->table) + div = _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) { @@ -159,7 +190,7 @@ 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(parent_rate, rate); + bestdiv = _div_round_up(divider, parent_rate, rate); bestdiv = bestdiv == 0 ? 1 : bestdiv; bestdiv = bestdiv > maxdiv ? maxdiv : bestdiv; return bestdiv; @@ -219,6 +250,10 @@ static int clk_divider_set_rate(struct clk_hw *hw, unsigned long rate, u32 val; div = DIV_ROUND_UP(parent_rate, rate); + + if (!_is_valid_div(divider, div)) + return -EINVAL; + value = _get_val(divider, div); if (value > div_mask(divider)) |