| Message ID | 20180227222701.9716-2-jernej.skrabec@siol.net (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi, On Tue, Feb 27, 2018 at 11:26:46PM +0100, Jernej Skrabec wrote: > Some NM PLLs doesn't work well when their output clock rate is set below > certain rate. > > Add support for that constrain. > > Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net> > --- > drivers/clk/sunxi-ng/ccu_nm.c | 11 +++++++---- > drivers/clk/sunxi-ng/ccu_nm.h | 27 +++++++++++++++++++++++++++ > 2 files changed, 34 insertions(+), 4 deletions(-) > > diff --git a/drivers/clk/sunxi-ng/ccu_nm.c b/drivers/clk/sunxi-ng/ccu_nm.c > index a16de092bf94..7fc743c78c1b 100644 > --- a/drivers/clk/sunxi-ng/ccu_nm.c > +++ b/drivers/clk/sunxi-ng/ccu_nm.c > @@ -20,7 +20,7 @@ struct _ccu_nm { > }; > > static void ccu_nm_find_best(unsigned long parent, unsigned long rate, > - struct _ccu_nm *nm) > + unsigned long min_rate, struct _ccu_nm *nm) > { > unsigned long best_rate = 0; > unsigned long best_n = 0, best_m = 0; > @@ -30,7 +30,7 @@ static void ccu_nm_find_best(unsigned long parent, unsigned long rate, > for (_m = nm->min_m; _m <= nm->max_m; _m++) { > unsigned long tmp_rate = parent * _n / _m; > > - if (tmp_rate > rate) > + if (tmp_rate > rate || tmp_rate < min_rate) > continue; > > if ((rate - tmp_rate) < (rate - best_rate)) { > @@ -117,6 +117,9 @@ static long ccu_nm_round_rate(struct clk_hw *hw, unsigned long rate, > if (nm->common.features & CCU_FEATURE_FIXED_POSTDIV) > rate *= nm->fixed_post_div; > > + if (rate < nm->min_rate) > + rate = nm->min_rate; > + I guess you can just return there. There's no point in trying to find the factors at this point, since the minimum should be a value that can be reached. > if (ccu_frac_helper_has_rate(&nm->common, &nm->frac, rate)) { > if (nm->common.features & CCU_FEATURE_FIXED_POSTDIV) > rate /= nm->fixed_post_div; > @@ -134,7 +137,7 @@ static long ccu_nm_round_rate(struct clk_hw *hw, unsigned long rate, > _nm.min_m = 1; > _nm.max_m = nm->m.max ?: 1 << nm->m.width; > > - ccu_nm_find_best(*parent_rate, rate, &_nm); > + ccu_nm_find_best(*parent_rate, rate, nm->min_rate, &_nm); Therefore, you don't need to change the prototype there either. Maxime
Hi, Dne sreda, 28. februar 2018 ob 08:34:40 CET je Maxime Ripard napisal(a): > Hi, > > On Tue, Feb 27, 2018 at 11:26:46PM +0100, Jernej Skrabec wrote: > > Some NM PLLs doesn't work well when their output clock rate is set below > > certain rate. > > > > Add support for that constrain. > > > > Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net> > > --- > > > > drivers/clk/sunxi-ng/ccu_nm.c | 11 +++++++---- > > drivers/clk/sunxi-ng/ccu_nm.h | 27 +++++++++++++++++++++++++++ > > 2 files changed, 34 insertions(+), 4 deletions(-) > > > > diff --git a/drivers/clk/sunxi-ng/ccu_nm.c b/drivers/clk/sunxi-ng/ccu_nm.c > > index a16de092bf94..7fc743c78c1b 100644 > > --- a/drivers/clk/sunxi-ng/ccu_nm.c > > +++ b/drivers/clk/sunxi-ng/ccu_nm.c > > @@ -20,7 +20,7 @@ struct _ccu_nm { > > > > }; > > > > static void ccu_nm_find_best(unsigned long parent, unsigned long rate, > > > > - struct _ccu_nm *nm) > > + unsigned long min_rate, struct _ccu_nm *nm) > > > > { > > > > unsigned long best_rate = 0; > > unsigned long best_n = 0, best_m = 0; > > > > @@ -30,7 +30,7 @@ static void ccu_nm_find_best(unsigned long parent, > > unsigned long rate,> > > for (_m = nm->min_m; _m <= nm->max_m; _m++) { > > > > unsigned long tmp_rate = parent * _n / _m; > > > > - if (tmp_rate > rate) > > + if (tmp_rate > rate || tmp_rate < min_rate) > > > > continue; > > > > if ((rate - tmp_rate) < (rate - best_rate)) { > > > > @@ -117,6 +117,9 @@ static long ccu_nm_round_rate(struct clk_hw *hw, > > unsigned long rate,> > > if (nm->common.features & CCU_FEATURE_FIXED_POSTDIV) > > > > rate *= nm->fixed_post_div; > > > > + if (rate < nm->min_rate) > > + rate = nm->min_rate; > > + > > I guess you can just return there. There's no point in trying to find > the factors at this point, since the minimum should be a value that > can be reached. > Right, I already tested it and it works. Best regards, Jernej > > if (ccu_frac_helper_has_rate(&nm->common, &nm->frac, rate)) { > > > > if (nm->common.features & CCU_FEATURE_FIXED_POSTDIV) > > > > rate /= nm->fixed_post_div; > > > > @@ -134,7 +137,7 @@ static long ccu_nm_round_rate(struct clk_hw *hw, > > unsigned long rate,> > > _nm.min_m = 1; > > _nm.max_m = nm->m.max ?: 1 << nm->m.width; > > > > - ccu_nm_find_best(*parent_rate, rate, &_nm); > > + ccu_nm_find_best(*parent_rate, rate, nm->min_rate, &_nm); > > Therefore, you don't need to change the prototype there either. > > Maxime > > -- > Maxime Ripard, Bootlin (formerly Free Electrons) > Embedded Linux and Kernel engineering > https://bootlin.com
diff --git a/drivers/clk/sunxi-ng/ccu_nm.c b/drivers/clk/sunxi-ng/ccu_nm.c index a16de092bf94..7fc743c78c1b 100644 --- a/drivers/clk/sunxi-ng/ccu_nm.c +++ b/drivers/clk/sunxi-ng/ccu_nm.c @@ -20,7 +20,7 @@ struct _ccu_nm { }; static void ccu_nm_find_best(unsigned long parent, unsigned long rate, - struct _ccu_nm *nm) + unsigned long min_rate, struct _ccu_nm *nm) { unsigned long best_rate = 0; unsigned long best_n = 0, best_m = 0; @@ -30,7 +30,7 @@ static void ccu_nm_find_best(unsigned long parent, unsigned long rate, for (_m = nm->min_m; _m <= nm->max_m; _m++) { unsigned long tmp_rate = parent * _n / _m; - if (tmp_rate > rate) + if (tmp_rate > rate || tmp_rate < min_rate) continue; if ((rate - tmp_rate) < (rate - best_rate)) { @@ -117,6 +117,9 @@ static long ccu_nm_round_rate(struct clk_hw *hw, unsigned long rate, if (nm->common.features & CCU_FEATURE_FIXED_POSTDIV) rate *= nm->fixed_post_div; + if (rate < nm->min_rate) + rate = nm->min_rate; + if (ccu_frac_helper_has_rate(&nm->common, &nm->frac, rate)) { if (nm->common.features & CCU_FEATURE_FIXED_POSTDIV) rate /= nm->fixed_post_div; @@ -134,7 +137,7 @@ static long ccu_nm_round_rate(struct clk_hw *hw, unsigned long rate, _nm.min_m = 1; _nm.max_m = nm->m.max ?: 1 << nm->m.width; - ccu_nm_find_best(*parent_rate, rate, &_nm); + ccu_nm_find_best(*parent_rate, rate, nm->min_rate, &_nm); rate = *parent_rate * _nm.n / _nm.m; if (nm->common.features & CCU_FEATURE_FIXED_POSTDIV) @@ -186,7 +189,7 @@ static int ccu_nm_set_rate(struct clk_hw *hw, unsigned long rate, &_nm.m, &_nm.n); } else { ccu_sdm_helper_disable(&nm->common, &nm->sdm); - ccu_nm_find_best(parent_rate, rate, &_nm); + ccu_nm_find_best(parent_rate, rate, nm->min_rate, &_nm); } spin_lock_irqsave(nm->common.lock, flags); diff --git a/drivers/clk/sunxi-ng/ccu_nm.h b/drivers/clk/sunxi-ng/ccu_nm.h index eba586b4c7d0..1d8b459c50b7 100644 --- a/drivers/clk/sunxi-ng/ccu_nm.h +++ b/drivers/clk/sunxi-ng/ccu_nm.h @@ -37,6 +37,7 @@ struct ccu_nm { struct ccu_sdm_internal sdm; unsigned int fixed_post_div; + unsigned int min_rate; struct ccu_common common; }; @@ -88,6 +89,32 @@ struct ccu_nm { }, \ } +#define SUNXI_CCU_NM_WITH_FRAC_GATE_LOCK_MIN(_struct, _name, _parent, \ + _reg, _min_rate, \ + _nshift, _nwidth, \ + _mshift, _mwidth, \ + _frac_en, _frac_sel, \ + _frac_rate_0, _frac_rate_1,\ + _gate, _lock, _flags) \ + struct ccu_nm _struct = { \ + .enable = _gate, \ + .lock = _lock, \ + .n = _SUNXI_CCU_MULT(_nshift, _nwidth), \ + .m = _SUNXI_CCU_DIV(_mshift, _mwidth), \ + .frac = _SUNXI_CCU_FRAC(_frac_en, _frac_sel, \ + _frac_rate_0, \ + _frac_rate_1), \ + .min_rate = _min_rate, \ + .common = { \ + .reg = _reg, \ + .features = CCU_FEATURE_FRACTIONAL, \ + .hw.init = CLK_HW_INIT(_name, \ + _parent, \ + &ccu_nm_ops, \ + _flags), \ + }, \ + } + #define SUNXI_CCU_NM_WITH_GATE_LOCK(_struct, _name, _parent, _reg, \ _nshift, _nwidth, \ _mshift, _mwidth, \
Some NM PLLs doesn't work well when their output clock rate is set below certain rate. Add support for that constrain. Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net> --- drivers/clk/sunxi-ng/ccu_nm.c | 11 +++++++---- drivers/clk/sunxi-ng/ccu_nm.h | 27 +++++++++++++++++++++++++++ 2 files changed, 34 insertions(+), 4 deletions(-)