diff options
| author | Lori Hikichi <lori.hikichi@broadcom.com> | 2017-08-14 21:00:39 +0200 |
|---|---|---|
| committer | Stephen Boyd <sboyd@codeaurora.org> | 2017-12-28 23:53:34 +0100 |
| commit | 85151a6b0b331f7bc4d9534d6138bfdd3e206b0d (patch) | |
| tree | 641aa0820acb441ee4a6633527fea365b9a5885f /drivers/clk/bcm | |
| parent | clk: iproc: Allow iproc pll to runtime calculate vco parameters (diff) | |
| download | linux-85151a6b0b331f7bc4d9534d6138bfdd3e206b0d.tar.xz linux-85151a6b0b331f7bc4d9534d6138bfdd3e206b0d.zip | |
clk: iproc: Fix error in the pll post divider rate calculation
The pll post divider code was using DIV_ROUND_UP when determining the
divider value best suited to produce the target frequency.
Using DIV_ROUND_CLOSEST will give us better divider values when
the division results in a small remainder.
Also, change the post divider clock over to the determine_rate api
instead of round_rate.
Signed-off-by: Simran Rai <ssimran@broadcom.com>
Signed-off-by: Lori Hikichi <lori.hikichi@broadcom.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Diffstat (limited to 'drivers/clk/bcm')
| -rw-r--r-- | drivers/clk/bcm/clk-iproc-pll.c | 33 |
1 files changed, 17 insertions, 16 deletions
diff --git a/drivers/clk/bcm/clk-iproc-pll.c b/drivers/clk/bcm/clk-iproc-pll.c index 9514ecf319b0..7df010b2edcd 100644 --- a/drivers/clk/bcm/clk-iproc-pll.c +++ b/drivers/clk/bcm/clk-iproc-pll.c @@ -602,25 +602,26 @@ static unsigned long iproc_clk_recalc_rate(struct clk_hw *hw, return clk->rate; } -static long iproc_clk_round_rate(struct clk_hw *hw, unsigned long rate, - unsigned long *parent_rate) +static int iproc_clk_determine_rate(struct clk_hw *hw, + struct clk_rate_request *req) { - unsigned int div; + unsigned int bestdiv; - if (rate == 0 || *parent_rate == 0) + if (req->rate == 0) return -EINVAL; + if (req->rate == req->best_parent_rate) + return 0; - if (rate == *parent_rate) - return *parent_rate; + bestdiv = DIV_ROUND_CLOSEST(req->best_parent_rate, req->rate); + if (bestdiv < 2) + req->rate = req->best_parent_rate; - div = DIV_ROUND_UP(*parent_rate, rate); - if (div < 2) - return *parent_rate; + if (bestdiv > 256) + bestdiv = 256; - if (div > 256) - div = 256; + req->rate = req->best_parent_rate / bestdiv; - return *parent_rate / div; + return 0; } static int iproc_clk_set_rate(struct clk_hw *hw, unsigned long rate, @@ -635,10 +636,10 @@ static int iproc_clk_set_rate(struct clk_hw *hw, unsigned long rate, if (rate == 0 || parent_rate == 0) return -EINVAL; + div = DIV_ROUND_CLOSEST(parent_rate, rate); if (ctrl->flags & IPROC_CLK_MCLK_DIV_BY_2) - div = DIV_ROUND_UP(parent_rate, rate * 2); - else - div = DIV_ROUND_UP(parent_rate, rate); + div /= 2; + if (div > 256) return -EINVAL; @@ -662,7 +663,7 @@ static const struct clk_ops iproc_clk_ops = { .enable = iproc_clk_enable, .disable = iproc_clk_disable, .recalc_rate = iproc_clk_recalc_rate, - .round_rate = iproc_clk_round_rate, + .determine_rate = iproc_clk_determine_rate, .set_rate = iproc_clk_set_rate, }; |