| Message ID | 1391426731-9392-3-git-send-email-b.brezillon@overkiz.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 03/02/2014 12:25, Boris BREZILLON : > Implement the determine_rate callback to choose the best parent clk that > fulfills the requested rate. > > Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Nice feature, thanks! > --- > drivers/clk/at91/clk-programmable.c | 56 +++++++++++++++++------------------ > 1 file changed, 28 insertions(+), 28 deletions(-) > > diff --git a/drivers/clk/at91/clk-programmable.c b/drivers/clk/at91/clk-programmable.c > index 02f62a0..8e242c7 100644 > --- a/drivers/clk/at91/clk-programmable.c > +++ b/drivers/clk/at91/clk-programmable.c > @@ -105,40 +105,40 @@ static unsigned long clk_programmable_recalc_rate(struct clk_hw *hw, > return parent_rate >> prog->pres; > } > > -static long clk_programmable_round_rate(struct clk_hw *hw, unsigned long rate, > - unsigned long *parent_rate) > +static long clk_programmable_determine_rate(struct clk_hw *hw, > + unsigned long rate, > + unsigned long *best_parent_rate, > + struct clk **best_parent_clk) > { > - unsigned long best_rate = *parent_rate; > - unsigned long best_diff; > - unsigned long new_diff; > - unsigned long cur_rate; > - int shift = shift; > - > - if (rate > *parent_rate) > - return *parent_rate; > - else > - best_diff = *parent_rate - rate; > - > - if (!best_diff) > - return best_rate; > + struct clk *parent = NULL; > + long best_rate = -EINVAL; > + unsigned long parent_rate; > + unsigned long tmp_rate; > + int shift; > + int i; > > - for (shift = 1; shift < PROG_PRES_MASK; shift++) { > - cur_rate = *parent_rate >> shift; > + for (i = 0; i < __clk_get_num_parents(hw->clk); i++) { > + parent = clk_get_parent_by_index(hw->clk, i); > + if (!parent) > + continue; > > - if (cur_rate > rate) > - new_diff = cur_rate - rate; > - else > - new_diff = rate - cur_rate; > + parent_rate = __clk_get_rate(parent); > + for (shift = 0; shift < PROG_PRES_MASK; shift++) { > + tmp_rate = parent_rate >> shift; > + if (tmp_rate <= rate) > + break; > + } > > - if (!new_diff) > - return cur_rate; > + if (tmp_rate > rate) > + continue; > > - if (new_diff < best_diff) { > - best_diff = new_diff; > - best_rate = cur_rate; > + if (best_rate < 0 || (rate - tmp_rate) < (rate - best_rate)) { > + best_rate = tmp_rate; > + *best_parent_rate = parent_rate; > + *best_parent_clk = parent; > } > > - if (rate > cur_rate) > + if (!best_rate) > break; > } > > @@ -231,7 +231,7 @@ static const struct clk_ops programmable_ops = { > .prepare = clk_programmable_prepare, > .is_prepared = clk_programmable_is_ready, > .recalc_rate = clk_programmable_recalc_rate, > - .round_rate = clk_programmable_round_rate, > + .determine_rate = clk_programmable_determine_rate, > .get_parent = clk_programmable_get_parent, > .set_parent = clk_programmable_set_parent, > .set_rate = clk_programmable_set_rate, >
diff --git a/drivers/clk/at91/clk-programmable.c b/drivers/clk/at91/clk-programmable.c index 02f62a0..8e242c7 100644 --- a/drivers/clk/at91/clk-programmable.c +++ b/drivers/clk/at91/clk-programmable.c @@ -105,40 +105,40 @@ static unsigned long clk_programmable_recalc_rate(struct clk_hw *hw, return parent_rate >> prog->pres; } -static long clk_programmable_round_rate(struct clk_hw *hw, unsigned long rate, - unsigned long *parent_rate) +static long clk_programmable_determine_rate(struct clk_hw *hw, + unsigned long rate, + unsigned long *best_parent_rate, + struct clk **best_parent_clk) { - unsigned long best_rate = *parent_rate; - unsigned long best_diff; - unsigned long new_diff; - unsigned long cur_rate; - int shift = shift; - - if (rate > *parent_rate) - return *parent_rate; - else - best_diff = *parent_rate - rate; - - if (!best_diff) - return best_rate; + struct clk *parent = NULL; + long best_rate = -EINVAL; + unsigned long parent_rate; + unsigned long tmp_rate; + int shift; + int i; - for (shift = 1; shift < PROG_PRES_MASK; shift++) { - cur_rate = *parent_rate >> shift; + for (i = 0; i < __clk_get_num_parents(hw->clk); i++) { + parent = clk_get_parent_by_index(hw->clk, i); + if (!parent) + continue; - if (cur_rate > rate) - new_diff = cur_rate - rate; - else - new_diff = rate - cur_rate; + parent_rate = __clk_get_rate(parent); + for (shift = 0; shift < PROG_PRES_MASK; shift++) { + tmp_rate = parent_rate >> shift; + if (tmp_rate <= rate) + break; + } - if (!new_diff) - return cur_rate; + if (tmp_rate > rate) + continue; - if (new_diff < best_diff) { - best_diff = new_diff; - best_rate = cur_rate; + if (best_rate < 0 || (rate - tmp_rate) < (rate - best_rate)) { + best_rate = tmp_rate; + *best_parent_rate = parent_rate; + *best_parent_clk = parent; } - if (rate > cur_rate) + if (!best_rate) break; } @@ -231,7 +231,7 @@ static const struct clk_ops programmable_ops = { .prepare = clk_programmable_prepare, .is_prepared = clk_programmable_is_ready, .recalc_rate = clk_programmable_recalc_rate, - .round_rate = clk_programmable_round_rate, + .determine_rate = clk_programmable_determine_rate, .get_parent = clk_programmable_get_parent, .set_parent = clk_programmable_set_parent, .set_rate = clk_programmable_set_rate,
Implement the determine_rate callback to choose the best parent clk that fulfills the requested rate. Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com> --- drivers/clk/at91/clk-programmable.c | 56 +++++++++++++++++------------------ 1 file changed, 28 insertions(+), 28 deletions(-)