| Message ID | 1400592297-22171-1-git-send-email-elder@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Quoting Alex Elder (2014-05-20 06:24:57) > Implement the clk->determine_rate method for Broadcom Kona peripheral > clocks. This allows a peripheral clock to be re-parented in order to > satisfy a rate change request. This takes the place of the previous > kona_peri_clk_round_rate() functionality, though that function remains > because it is used by the new one. > > The parent clock that allows the peripheral clock to produce a rate > closest to the one requested is the one selected, though the current > parent is used by default. > > Signed-off-by: Alex Elder <elder@linaro.org> > --- > This patch is based on Mike Turquette's current "clk-next" branch. > 6ed8eb5 Merge tag 'clk-hisi-for-v3.16' of https://git.kern... > > It is available here: > http://git.linaro.org/landing-teams/working/broadcom/kernel.git > Branch review/bcm-determine-rate > > drivers/clk/bcm/clk-kona.c | 53 +++++++++++++++++++++++++++++++++++++++++++++- > 1 file changed, 52 insertions(+), 1 deletion(-) > > diff --git a/drivers/clk/bcm/clk-kona.c b/drivers/clk/bcm/clk-kona.c > index d603c4e..1a4eccc 100644 > --- a/drivers/clk/bcm/clk-kona.c > +++ b/drivers/clk/bcm/clk-kona.c > @@ -1031,6 +1031,57 @@ static long kona_peri_clk_round_rate(struct clk_hw *hw, unsigned long rate, > rate ? rate : 1, *parent_rate, NULL); > } > > +static long kona_peri_clk_determine_rate(struct clk_hw *hw, unsigned long rate, > + unsigned long *best_parent_rate, struct clk **best_parent) > +{ > + struct kona_clk *bcm_clk = to_kona_clk(hw); > + struct clk *clk = hw->clk; > + struct clk *current_parent; > + unsigned long parent_rate; > + unsigned long best_delta; > + unsigned long best_rate; > + u32 parent_count; > + u32 which; > + > + /* > + * If there is no other parent to choose, use the current one. > + * Note: We don't honor (or use) CLK_SET_RATE_NO_REPARENT. > + */ A WARN_ONCE is appropriate upon detection of CLK_SET_RATE_NO_REPARENT. It will certainly help someone that is debugging why that flag has no effect. Otherwise the patch looks good to me. Regards, Mike > + parent_count = (u32)bcm_clk->init_data.num_parents; > + if (parent_count < 2) > + return kona_peri_clk_round_rate(hw, rate, best_parent_rate); > + > + /* Unless we can do better, stick with current parent */ > + current_parent = clk_get_parent(clk); > + parent_rate = __clk_get_rate(current_parent); > + best_rate = kona_peri_clk_round_rate(hw, rate, &parent_rate); > + best_delta = abs(best_rate - rate); > + > + /* Check whether any other parent clock can produce a better result */ > + for (which = 0; which < parent_count; which++) { > + struct clk *parent = clk_get_parent_by_index(clk, which); > + unsigned long delta; > + unsigned long other_rate; > + > + BUG_ON(!parent); > + if (parent == current_parent) > + continue; > + > + /* We don't support CLK_SET_RATE_PARENT */ > + parent_rate = __clk_get_rate(parent); > + other_rate = kona_peri_clk_round_rate(hw, rate, &parent_rate); > + delta = abs(other_rate - rate); > + if (delta < best_delta) { > + best_delta = delta; > + best_rate = other_rate; > + *best_parent = parent; > + *best_parent_rate = parent_rate; > + } > + } > + > + return best_rate; > +} > + > static int kona_peri_clk_set_parent(struct clk_hw *hw, u8 index) > { > struct kona_clk *bcm_clk = to_kona_clk(hw); > @@ -1135,7 +1186,7 @@ struct clk_ops kona_peri_clk_ops = { > .disable = kona_peri_clk_disable, > .is_enabled = kona_peri_clk_is_enabled, > .recalc_rate = kona_peri_clk_recalc_rate, > - .round_rate = kona_peri_clk_round_rate, > + .determine_rate = kona_peri_clk_determine_rate, > .set_parent = kona_peri_clk_set_parent, > .get_parent = kona_peri_clk_get_parent, > .set_rate = kona_peri_clk_set_rate, > -- > 1.9.1 >
On 05/23/2014 06:18 PM, Mike Turquette wrote: > Quoting Alex Elder (2014-05-20 06:24:57) >> Implement the clk->determine_rate method for Broadcom Kona peripheral >> clocks. This allows a peripheral clock to be re-parented in order to >> satisfy a rate change request. This takes the place of the previous >> kona_peri_clk_round_rate() functionality, though that function remains >> because it is used by the new one. >> >> The parent clock that allows the peripheral clock to produce a rate >> closest to the one requested is the one selected, though the current >> parent is used by default. >> >> Signed-off-by: Alex Elder <elder@linaro.org> >> --- >> This patch is based on Mike Turquette's current "clk-next" branch. >> 6ed8eb5 Merge tag 'clk-hisi-for-v3.16' of https://git.kern... >> >> It is available here: >> http://git.linaro.org/landing-teams/working/broadcom/kernel.git >> Branch review/bcm-determine-rate >> >> drivers/clk/bcm/clk-kona.c | 53 +++++++++++++++++++++++++++++++++++++++++++++- >> 1 file changed, 52 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/clk/bcm/clk-kona.c b/drivers/clk/bcm/clk-kona.c >> index d603c4e..1a4eccc 100644 >> --- a/drivers/clk/bcm/clk-kona.c >> +++ b/drivers/clk/bcm/clk-kona.c >> @@ -1031,6 +1031,57 @@ static long kona_peri_clk_round_rate(struct clk_hw *hw, unsigned long rate, >> rate ? rate : 1, *parent_rate, NULL); >> } >> >> +static long kona_peri_clk_determine_rate(struct clk_hw *hw, unsigned long rate, >> + unsigned long *best_parent_rate, struct clk **best_parent) >> +{ >> + struct kona_clk *bcm_clk = to_kona_clk(hw); >> + struct clk *clk = hw->clk; >> + struct clk *current_parent; >> + unsigned long parent_rate; >> + unsigned long best_delta; >> + unsigned long best_rate; >> + u32 parent_count; >> + u32 which; >> + >> + /* >> + * If there is no other parent to choose, use the current one. >> + * Note: We don't honor (or use) CLK_SET_RATE_NO_REPARENT. >> + */ > > A WARN_ONCE is appropriate upon detection of CLK_SET_RATE_NO_REPARENT. > It will certainly help someone that is debugging why that flag has no > effect. I'll add that. > Otherwise the patch looks good to me. Would you like me to send an updated patch as a pull request? Thanks. -Alex > Regards, > Mike > >> + parent_count = (u32)bcm_clk->init_data.num_parents; >> + if (parent_count < 2) >> + return kona_peri_clk_round_rate(hw, rate, best_parent_rate); >> + >> + /* Unless we can do better, stick with current parent */ >> + current_parent = clk_get_parent(clk); >> + parent_rate = __clk_get_rate(current_parent); >> + best_rate = kona_peri_clk_round_rate(hw, rate, &parent_rate); >> + best_delta = abs(best_rate - rate); >> + >> + /* Check whether any other parent clock can produce a better result */ >> + for (which = 0; which < parent_count; which++) { >> + struct clk *parent = clk_get_parent_by_index(clk, which); >> + unsigned long delta; >> + unsigned long other_rate; >> + >> + BUG_ON(!parent); >> + if (parent == current_parent) >> + continue; >> + >> + /* We don't support CLK_SET_RATE_PARENT */ >> + parent_rate = __clk_get_rate(parent); >> + other_rate = kona_peri_clk_round_rate(hw, rate, &parent_rate); >> + delta = abs(other_rate - rate); >> + if (delta < best_delta) { >> + best_delta = delta; >> + best_rate = other_rate; >> + *best_parent = parent; >> + *best_parent_rate = parent_rate; >> + } >> + } >> + >> + return best_rate; >> +} >> + >> static int kona_peri_clk_set_parent(struct clk_hw *hw, u8 index) >> { >> struct kona_clk *bcm_clk = to_kona_clk(hw); >> @@ -1135,7 +1186,7 @@ struct clk_ops kona_peri_clk_ops = { >> .disable = kona_peri_clk_disable, >> .is_enabled = kona_peri_clk_is_enabled, >> .recalc_rate = kona_peri_clk_recalc_rate, >> - .round_rate = kona_peri_clk_round_rate, >> + .determine_rate = kona_peri_clk_determine_rate, >> .set_parent = kona_peri_clk_set_parent, >> .get_parent = kona_peri_clk_get_parent, >> .set_rate = kona_peri_clk_set_rate, >> -- >> 1.9.1 >>
Quoting Alex Elder (2014-05-23 16:24:31) > On 05/23/2014 06:18 PM, Mike Turquette wrote: > > Quoting Alex Elder (2014-05-20 06:24:57) > >> Implement the clk->determine_rate method for Broadcom Kona peripheral > >> clocks. This allows a peripheral clock to be re-parented in order to > >> satisfy a rate change request. This takes the place of the previous > >> kona_peri_clk_round_rate() functionality, though that function remains > >> because it is used by the new one. > >> > >> The parent clock that allows the peripheral clock to produce a rate > >> closest to the one requested is the one selected, though the current > >> parent is used by default. > >> > >> Signed-off-by: Alex Elder <elder@linaro.org> > >> --- > >> This patch is based on Mike Turquette's current "clk-next" branch. > >> 6ed8eb5 Merge tag 'clk-hisi-for-v3.16' of https://git.kern... > >> > >> It is available here: > >> http://git.linaro.org/landing-teams/working/broadcom/kernel.git > >> Branch review/bcm-determine-rate > >> > >> drivers/clk/bcm/clk-kona.c | 53 +++++++++++++++++++++++++++++++++++++++++++++- > >> 1 file changed, 52 insertions(+), 1 deletion(-) > >> > >> diff --git a/drivers/clk/bcm/clk-kona.c b/drivers/clk/bcm/clk-kona.c > >> index d603c4e..1a4eccc 100644 > >> --- a/drivers/clk/bcm/clk-kona.c > >> +++ b/drivers/clk/bcm/clk-kona.c > >> @@ -1031,6 +1031,57 @@ static long kona_peri_clk_round_rate(struct clk_hw *hw, unsigned long rate, > >> rate ? rate : 1, *parent_rate, NULL); > >> } > >> > >> +static long kona_peri_clk_determine_rate(struct clk_hw *hw, unsigned long rate, > >> + unsigned long *best_parent_rate, struct clk **best_parent) > >> +{ > >> + struct kona_clk *bcm_clk = to_kona_clk(hw); > >> + struct clk *clk = hw->clk; > >> + struct clk *current_parent; > >> + unsigned long parent_rate; > >> + unsigned long best_delta; > >> + unsigned long best_rate; > >> + u32 parent_count; > >> + u32 which; > >> + > >> + /* > >> + * If there is no other parent to choose, use the current one. > >> + * Note: We don't honor (or use) CLK_SET_RATE_NO_REPARENT. > >> + */ > > > > A WARN_ONCE is appropriate upon detection of CLK_SET_RATE_NO_REPARENT. > > It will certainly help someone that is debugging why that flag has no > > effect. > > I'll add that. Thanks! > > > Otherwise the patch looks good to me. > > Would you like me to send an updated patch as a pull request? It's up to you. For a single patch I can easily pick it. If you want to bundle it up with the other pending patches (prereq clocks, etc) then a pull request would be nice once all that stuff gets sorted. Regards, Mike > > Thanks. > > -Alex > > > Regards, > > Mike > > > >> + parent_count = (u32)bcm_clk->init_data.num_parents; > >> + if (parent_count < 2) > >> + return kona_peri_clk_round_rate(hw, rate, best_parent_rate); > >> + > >> + /* Unless we can do better, stick with current parent */ > >> + current_parent = clk_get_parent(clk); > >> + parent_rate = __clk_get_rate(current_parent); > >> + best_rate = kona_peri_clk_round_rate(hw, rate, &parent_rate); > >> + best_delta = abs(best_rate - rate); > >> + > >> + /* Check whether any other parent clock can produce a better result */ > >> + for (which = 0; which < parent_count; which++) { > >> + struct clk *parent = clk_get_parent_by_index(clk, which); > >> + unsigned long delta; > >> + unsigned long other_rate; > >> + > >> + BUG_ON(!parent); > >> + if (parent == current_parent) > >> + continue; > >> + > >> + /* We don't support CLK_SET_RATE_PARENT */ > >> + parent_rate = __clk_get_rate(parent); > >> + other_rate = kona_peri_clk_round_rate(hw, rate, &parent_rate); > >> + delta = abs(other_rate - rate); > >> + if (delta < best_delta) { > >> + best_delta = delta; > >> + best_rate = other_rate; > >> + *best_parent = parent; > >> + *best_parent_rate = parent_rate; > >> + } > >> + } > >> + > >> + return best_rate; > >> +} > >> + > >> static int kona_peri_clk_set_parent(struct clk_hw *hw, u8 index) > >> { > >> struct kona_clk *bcm_clk = to_kona_clk(hw); > >> @@ -1135,7 +1186,7 @@ struct clk_ops kona_peri_clk_ops = { > >> .disable = kona_peri_clk_disable, > >> .is_enabled = kona_peri_clk_is_enabled, > >> .recalc_rate = kona_peri_clk_recalc_rate, > >> - .round_rate = kona_peri_clk_round_rate, > >> + .determine_rate = kona_peri_clk_determine_rate, > >> .set_parent = kona_peri_clk_set_parent, > >> .get_parent = kona_peri_clk_get_parent, > >> .set_rate = kona_peri_clk_set_rate, > >> -- > >> 1.9.1 > >> >
diff --git a/drivers/clk/bcm/clk-kona.c b/drivers/clk/bcm/clk-kona.c index d603c4e..1a4eccc 100644 --- a/drivers/clk/bcm/clk-kona.c +++ b/drivers/clk/bcm/clk-kona.c @@ -1031,6 +1031,57 @@ static long kona_peri_clk_round_rate(struct clk_hw *hw, unsigned long rate, rate ? rate : 1, *parent_rate, NULL); } +static long kona_peri_clk_determine_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *best_parent_rate, struct clk **best_parent) +{ + struct kona_clk *bcm_clk = to_kona_clk(hw); + struct clk *clk = hw->clk; + struct clk *current_parent; + unsigned long parent_rate; + unsigned long best_delta; + unsigned long best_rate; + u32 parent_count; + u32 which; + + /* + * If there is no other parent to choose, use the current one. + * Note: We don't honor (or use) CLK_SET_RATE_NO_REPARENT. + */ + parent_count = (u32)bcm_clk->init_data.num_parents; + if (parent_count < 2) + return kona_peri_clk_round_rate(hw, rate, best_parent_rate); + + /* Unless we can do better, stick with current parent */ + current_parent = clk_get_parent(clk); + parent_rate = __clk_get_rate(current_parent); + best_rate = kona_peri_clk_round_rate(hw, rate, &parent_rate); + best_delta = abs(best_rate - rate); + + /* Check whether any other parent clock can produce a better result */ + for (which = 0; which < parent_count; which++) { + struct clk *parent = clk_get_parent_by_index(clk, which); + unsigned long delta; + unsigned long other_rate; + + BUG_ON(!parent); + if (parent == current_parent) + continue; + + /* We don't support CLK_SET_RATE_PARENT */ + parent_rate = __clk_get_rate(parent); + other_rate = kona_peri_clk_round_rate(hw, rate, &parent_rate); + delta = abs(other_rate - rate); + if (delta < best_delta) { + best_delta = delta; + best_rate = other_rate; + *best_parent = parent; + *best_parent_rate = parent_rate; + } + } + + return best_rate; +} + static int kona_peri_clk_set_parent(struct clk_hw *hw, u8 index) { struct kona_clk *bcm_clk = to_kona_clk(hw); @@ -1135,7 +1186,7 @@ struct clk_ops kona_peri_clk_ops = { .disable = kona_peri_clk_disable, .is_enabled = kona_peri_clk_is_enabled, .recalc_rate = kona_peri_clk_recalc_rate, - .round_rate = kona_peri_clk_round_rate, + .determine_rate = kona_peri_clk_determine_rate, .set_parent = kona_peri_clk_set_parent, .get_parent = kona_peri_clk_get_parent, .set_rate = kona_peri_clk_set_rate,
Implement the clk->determine_rate method for Broadcom Kona peripheral clocks. This allows a peripheral clock to be re-parented in order to satisfy a rate change request. This takes the place of the previous kona_peri_clk_round_rate() functionality, though that function remains because it is used by the new one. The parent clock that allows the peripheral clock to produce a rate closest to the one requested is the one selected, though the current parent is used by default. Signed-off-by: Alex Elder <elder@linaro.org> --- This patch is based on Mike Turquette's current "clk-next" branch. 6ed8eb5 Merge tag 'clk-hisi-for-v3.16' of https://git.kern... It is available here: http://git.linaro.org/landing-teams/working/broadcom/kernel.git Branch review/bcm-determine-rate drivers/clk/bcm/clk-kona.c | 53 +++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 52 insertions(+), 1 deletion(-)