| Message ID | 2257244.FrPXR4AKP7@diego (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Heiko, Seems to be good, tested on stih416 board. Only small remarks below Best Regards Gabriel. On 22 June 2014 22:43, Heiko Stübner <heiko@sntech.de> wrote: > From: Boris BREZILLON <b.brezillon@overkiz.com> > > In case the rate_hw does not implement determine_rate, but only round_rate > we fallback to best_parent selection if mux_hw is present and support > reparenting. > > Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com> > > This also fixes a rate calculation problem when using the standard div and > mux ops, as in this case currently only the mux->determine_rate is used > in the composite rate calculation. > So when for example the composite clock has two parents at 600 and 800MHz, > the requested rate is 75MHz, which the divider could provide, without this > change the rate would be set 600MHz ignoring the divider completely. > This may be way out of spec for the component. > > [fixed the output to actually return a rate instead of the diff] > Signed-off-by: Heiko Stuebner <heiko@sntech.de> > --- > drivers/clk/clk-composite.c | 51 ++++++++++++++++++++++++++++++++++++++++++++- > 1 file changed, 50 insertions(+), 1 deletion(-) > > diff --git a/drivers/clk/clk-composite.c b/drivers/clk/clk-composite.c > index 57a078e..0a4cd21 100644 > --- a/drivers/clk/clk-composite.c > +++ b/drivers/clk/clk-composite.c > @@ -64,11 +64,59 @@ static long clk_composite_determine_rate(struct clk_hw *hw, unsigned long rate, > const struct clk_ops *mux_ops = composite->mux_ops; > struct clk_hw *rate_hw = composite->rate_hw; > struct clk_hw *mux_hw = composite->mux_hw; > + struct clk *parent; > + unsigned long parent_rate; > + long tmp_rate, best_rate; > + unsigned long rate_diff; > + unsigned long best_rate_diff = ULONG_MAX; > + int i; > > if (rate_hw && rate_ops && rate_ops->determine_rate) { > rate_hw->clk = hw->clk; > return rate_ops->determine_rate(rate_hw, rate, best_parent_rate, > best_parent_p); > + } else if (rate_hw && rate_ops && rate_ops->round_rate && > + mux_hw && mux_ops && mux_ops->set_parent) { > + *best_parent_p = NULL; > + > + if (__clk_get_flags(hw->clk) & CLK_SET_RATE_NO_REPARENT) { > + *best_parent_p = clk_get_parent(mux_hw->clk); > + *best_parent_rate = __clk_get_rate(*best_parent_p); > + > + return rate_ops->round_rate(rate_hw, rate, > + best_parent_rate); > + } > + > + for (i = 0; i < __clk_get_num_parents(mux_hw->clk); i++) { > + parent = clk_get_parent_by_index(mux_hw->clk, i); > + if (!parent) > + continue; > + > + parent_rate = __clk_get_rate(parent); > + > + tmp_rate = rate_ops->round_rate(rate_hw, rate, > + &parent_rate); > + if (tmp_rate < 0) > + continue; > + > + if (tmp_rate < rate) > + rate_diff = rate - tmp_rate; > + else > + rate_diff = tmp_rate - rate; rate_dif = abs(rate - tmp_rate) is not better ? > + > + if (!rate_diff || !*best_parent_p > + || best_rate_diff > rate_diff) { > + *best_parent_p = parent; > + *best_parent_rate = parent_rate; > + best_rate_diff = rate_diff; > + best_rate = tmp_rate; > + } > + > + if (!rate_diff) > + return rate; > + } > + > + return best_rate; warning compilation: 'best_rate' may be used uninitialized in this function > } else if (mux_hw && mux_ops && mux_ops->determine_rate) { > mux_hw->clk = hw->clk; > return mux_ops->determine_rate(mux_hw, rate, best_parent_rate, > @@ -196,7 +244,8 @@ struct clk *clk_register_composite(struct device *dev, const char *name, > composite->rate_hw = rate_hw; > composite->rate_ops = rate_ops; > clk_composite_ops->recalc_rate = clk_composite_recalc_rate; > - if (rate_ops->determine_rate) > + if (rate_ops->determine_rate || > + (rate_ops->round_rate && clk_composite_ops->set_parent)) > clk_composite_ops->determine_rate = clk_composite_determine_rate; > } > > -- > 1.9.0 > > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
diff --git a/drivers/clk/clk-composite.c b/drivers/clk/clk-composite.c index 57a078e..0a4cd21 100644 --- a/drivers/clk/clk-composite.c +++ b/drivers/clk/clk-composite.c @@ -64,11 +64,59 @@ static long clk_composite_determine_rate(struct clk_hw *hw, unsigned long rate, const struct clk_ops *mux_ops = composite->mux_ops; struct clk_hw *rate_hw = composite->rate_hw; struct clk_hw *mux_hw = composite->mux_hw; + struct clk *parent; + unsigned long parent_rate; + long tmp_rate, best_rate; + unsigned long rate_diff; + unsigned long best_rate_diff = ULONG_MAX; + int i; if (rate_hw && rate_ops && rate_ops->determine_rate) { rate_hw->clk = hw->clk; return rate_ops->determine_rate(rate_hw, rate, best_parent_rate, best_parent_p); + } else if (rate_hw && rate_ops && rate_ops->round_rate && + mux_hw && mux_ops && mux_ops->set_parent) { + *best_parent_p = NULL; + + if (__clk_get_flags(hw->clk) & CLK_SET_RATE_NO_REPARENT) { + *best_parent_p = clk_get_parent(mux_hw->clk); + *best_parent_rate = __clk_get_rate(*best_parent_p); + + return rate_ops->round_rate(rate_hw, rate, + best_parent_rate); + } + + for (i = 0; i < __clk_get_num_parents(mux_hw->clk); i++) { + parent = clk_get_parent_by_index(mux_hw->clk, i); + if (!parent) + continue; + + parent_rate = __clk_get_rate(parent); + + tmp_rate = rate_ops->round_rate(rate_hw, rate, + &parent_rate); + if (tmp_rate < 0) + continue; + + if (tmp_rate < rate) + rate_diff = rate - tmp_rate; + else + rate_diff = tmp_rate - rate; + + if (!rate_diff || !*best_parent_p + || best_rate_diff > rate_diff) { + *best_parent_p = parent; + *best_parent_rate = parent_rate; + best_rate_diff = rate_diff; + best_rate = tmp_rate; + } + + if (!rate_diff) + return rate; + } + + return best_rate; } else if (mux_hw && mux_ops && mux_ops->determine_rate) { mux_hw->clk = hw->clk; return mux_ops->determine_rate(mux_hw, rate, best_parent_rate, @@ -196,7 +244,8 @@ struct clk *clk_register_composite(struct device *dev, const char *name, composite->rate_hw = rate_hw; composite->rate_ops = rate_ops; clk_composite_ops->recalc_rate = clk_composite_recalc_rate; - if (rate_ops->determine_rate) + if (rate_ops->determine_rate || + (rate_ops->round_rate && clk_composite_ops->set_parent)) clk_composite_ops->determine_rate = clk_composite_determine_rate; }