| Message ID | 20190318105045.26943-1-nicolas.ferre@microchip.com (mailing list archive) |
|---|---|
| State | Accepted, archived |
| Headers | show |
| Series | [v2] clk: at91: fix programmable clock for sama5d2 | expand |
Quoting Nicolas Ferre (2019-03-18 03:50:45) > From: Matthias Wieloch <matthias.wieloch@few-bauer.de> > > The prescaler formula of the programmable clock has changed for sama5d2. Update > the driver accordingly. > > Fixes: a2038077de9a ("clk: at91: add sama5d2 PMC driver") > Cc: <stable@vger.kernel.org> # v4.20+ > Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com> > [nicolas.ferre@microchip.com: adapt the prescaler range, > fix clk_programmable_recalc_rate, split patch] > Signed-off-by: Matthias Wieloch <matthias.wieloch@few-bauer.de> > Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> > --- > v2: adapt to v5.1-rc1 > remove unneeded sentence about DT in commit message > > Stephen, > > I think it would be good to see this fix going upstream during v5.1-rc phase. Ok. I can apply this clk-fixes. I presume that things are real bad and it can't wait until v5.2? > @@ -60,10 +68,18 @@ static int clk_programmable_determine_rate(struct clk_hw *hw, > continue; > > parent_rate = clk_hw_get_rate(parent); > - for (shift = 0; shift < PROG_PRES_MASK; shift++) { > - tmp_rate = parent_rate >> shift; > - if (tmp_rate <= req->rate) > - break; > + if (layout->is_pres_direct) { > + for (shift = 0; shift <= layout->pres_mask; shift++) { > + tmp_rate = parent_rate / (shift + 1); > + if (tmp_rate <= req->rate) > + break; > + } > + } else { > + for (shift = 0; shift < layout->pres_mask; shift++) { > + tmp_rate = parent_rate >> shift; > + if (tmp_rate <= req->rate) > + break; > + } This looks like a lot of copy paste when the if statement could have been pulled into the for loop instead of duplicating the loops and surrounding if condition check for tmp_rate. > } > > if (tmp_rate > req->rate)
Stephen, Thanks for the review On 18/03/2019 at 20:54, Stephen Boyd wrote: > Quoting Nicolas Ferre (2019-03-18 03:50:45) >> From: Matthias Wieloch <matthias.wieloch@few-bauer.de> >> >> The prescaler formula of the programmable clock has changed for sama5d2. Update >> the driver accordingly. >> >> Fixes: a2038077de9a ("clk: at91: add sama5d2 PMC driver") >> Cc: <stable@vger.kernel.org> # v4.20+ >> Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com> >> [nicolas.ferre@microchip.com: adapt the prescaler range, >> fix clk_programmable_recalc_rate, split patch] >> Signed-off-by: Matthias Wieloch <matthias.wieloch@few-bauer.de> >> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> >> --- >> v2: adapt to v5.1-rc1 >> remove unneeded sentence about DT in commit message >> >> Stephen, >> >> I think it would be good to see this fix going upstream during v5.1-rc phase. > > Ok. I can apply this clk-fixes. I presume that things are real bad and > it can't wait until v5.2? To be perfectly clear, it's not a regression. But as we're at the very beginning of the '-rc' phase and as it's a bug, I was thinking about adding it now. But you to choose, no problem either way. >> @@ -60,10 +68,18 @@ static int clk_programmable_determine_rate(struct clk_hw *hw, >> continue; >> >> parent_rate = clk_hw_get_rate(parent); >> - for (shift = 0; shift < PROG_PRES_MASK; shift++) { >> - tmp_rate = parent_rate >> shift; >> - if (tmp_rate <= req->rate) >> - break; >> + if (layout->is_pres_direct) { >> + for (shift = 0; shift <= layout->pres_mask; shift++) { >> + tmp_rate = parent_rate / (shift + 1); >> + if (tmp_rate <= req->rate) >> + break; >> + } >> + } else { >> + for (shift = 0; shift < layout->pres_mask; shift++) { >> + tmp_rate = parent_rate >> shift; >> + if (tmp_rate <= req->rate) >> + break; >> + } > > This looks like a lot of copy paste when the if statement could have been > pulled into the for loop instead of duplicating the loops and > surrounding if condition check for tmp_rate. Stop condition of loops not being the same made me separate them instead of adding artificial test conditions for shift == layout->pres_mask. I'm not sure the other way around is more obvious then... > >> } >> >> if (tmp_rate > req->rate)
On 19/03/2019 08:28:40+0000, Nicolas Ferre wrote: > > Ok. I can apply this clk-fixes. I presume that things are real bad and > > it can't wait until v5.2? > > To be perfectly clear, it's not a regression. > But as we're at the very beginning of the '-rc' phase and as it's a bug, > I was thinking about adding it now. But you to choose, no problem either > way. > > >> @@ -60,10 +68,18 @@ static int clk_programmable_determine_rate(struct clk_hw *hw, > >> continue; > >> > >> parent_rate = clk_hw_get_rate(parent); > >> - for (shift = 0; shift < PROG_PRES_MASK; shift++) { > >> - tmp_rate = parent_rate >> shift; > >> - if (tmp_rate <= req->rate) > >> - break; > >> + if (layout->is_pres_direct) { > >> + for (shift = 0; shift <= layout->pres_mask; shift++) { > >> + tmp_rate = parent_rate / (shift + 1); > >> + if (tmp_rate <= req->rate) > >> + break; > >> + } > >> + } else { > >> + for (shift = 0; shift < layout->pres_mask; shift++) { > >> + tmp_rate = parent_rate >> shift; > >> + if (tmp_rate <= req->rate) > >> + break; > >> + } > > > > This looks like a lot of copy paste when the if statement could have been > > pulled into the for loop instead of duplicating the loops and > > surrounding if condition check for tmp_rate. > > Stop condition of loops not being the same made me separate them instead > of adding artificial test conditions for shift == layout->pres_mask. I'm > not sure the other way around is more obvious then... > I also tried different ways (e.g. setting up a different determine_rate for the sama5d2) but this ended up being the more concise one.
Quoting Nicolas Ferre (2019-03-18 03:50:45) > From: Matthias Wieloch <matthias.wieloch@few-bauer.de> > > The prescaler formula of the programmable clock has changed for sama5d2. Update > the driver accordingly. > > Fixes: a2038077de9a ("clk: at91: add sama5d2 PMC driver") > Cc: <stable@vger.kernel.org> # v4.20+ > Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com> > [nicolas.ferre@microchip.com: adapt the prescaler range, > fix clk_programmable_recalc_rate, split patch] > Signed-off-by: Matthias Wieloch <matthias.wieloch@few-bauer.de> > Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> > --- Applied to clk-fixes
diff --git a/drivers/clk/at91/clk-programmable.c b/drivers/clk/at91/clk-programmable.c index 89d6f3736dbf..f8edbb65eda3 100644 --- a/drivers/clk/at91/clk-programmable.c +++ b/drivers/clk/at91/clk-programmable.c @@ -20,8 +20,7 @@ #define PROG_ID_MAX 7 #define PROG_STATUS_MASK(id) (1 << ((id) + 8)) -#define PROG_PRES_MASK 0x7 -#define PROG_PRES(layout, pckr) ((pckr >> layout->pres_shift) & PROG_PRES_MASK) +#define PROG_PRES(layout, pckr) ((pckr >> layout->pres_shift) & layout->pres_mask) #define PROG_MAX_RM9200_CSS 3 struct clk_programmable { @@ -37,20 +36,29 @@ static unsigned long clk_programmable_recalc_rate(struct clk_hw *hw, unsigned long parent_rate) { struct clk_programmable *prog = to_clk_programmable(hw); + const struct clk_programmable_layout *layout = prog->layout; unsigned int pckr; + unsigned long rate; regmap_read(prog->regmap, AT91_PMC_PCKR(prog->id), &pckr); - return parent_rate >> PROG_PRES(prog->layout, pckr); + if (layout->is_pres_direct) + rate = parent_rate / (PROG_PRES(layout, pckr) + 1); + else + rate = parent_rate >> PROG_PRES(layout, pckr); + + return rate; } static int clk_programmable_determine_rate(struct clk_hw *hw, struct clk_rate_request *req) { + struct clk_programmable *prog = to_clk_programmable(hw); + const struct clk_programmable_layout *layout = prog->layout; struct clk_hw *parent; long best_rate = -EINVAL; unsigned long parent_rate; - unsigned long tmp_rate; + unsigned long tmp_rate = 0; int shift; int i; @@ -60,10 +68,18 @@ static int clk_programmable_determine_rate(struct clk_hw *hw, continue; parent_rate = clk_hw_get_rate(parent); - for (shift = 0; shift < PROG_PRES_MASK; shift++) { - tmp_rate = parent_rate >> shift; - if (tmp_rate <= req->rate) - break; + if (layout->is_pres_direct) { + for (shift = 0; shift <= layout->pres_mask; shift++) { + tmp_rate = parent_rate / (shift + 1); + if (tmp_rate <= req->rate) + break; + } + } else { + for (shift = 0; shift < layout->pres_mask; shift++) { + tmp_rate = parent_rate >> shift; + if (tmp_rate <= req->rate) + break; + } } if (tmp_rate > req->rate) @@ -137,16 +153,23 @@ static int clk_programmable_set_rate(struct clk_hw *hw, unsigned long rate, if (!div) return -EINVAL; - shift = fls(div) - 1; + if (layout->is_pres_direct) { + shift = div - 1; - if (div != (1 << shift)) - return -EINVAL; + if (shift > layout->pres_mask) + return -EINVAL; + } else { + shift = fls(div) - 1; - if (shift >= PROG_PRES_MASK) - return -EINVAL; + if (div != (1 << shift)) + return -EINVAL; + + if (shift >= layout->pres_mask) + return -EINVAL; + } regmap_update_bits(prog->regmap, AT91_PMC_PCKR(prog->id), - PROG_PRES_MASK << layout->pres_shift, + layout->pres_mask << layout->pres_shift, shift << layout->pres_shift); return 0; @@ -202,19 +225,25 @@ at91_clk_register_programmable(struct regmap *regmap, } const struct clk_programmable_layout at91rm9200_programmable_layout = { + .pres_mask = 0x7, .pres_shift = 2, .css_mask = 0x3, .have_slck_mck = 0, + .is_pres_direct = 0, }; const struct clk_programmable_layout at91sam9g45_programmable_layout = { + .pres_mask = 0x7, .pres_shift = 2, .css_mask = 0x3, .have_slck_mck = 1, + .is_pres_direct = 0, }; const struct clk_programmable_layout at91sam9x5_programmable_layout = { + .pres_mask = 0x7, .pres_shift = 4, .css_mask = 0x7, .have_slck_mck = 0, + .is_pres_direct = 0, }; diff --git a/drivers/clk/at91/pmc.h b/drivers/clk/at91/pmc.h index 672a79bda88c..a0e5ce9c9b9e 100644 --- a/drivers/clk/at91/pmc.h +++ b/drivers/clk/at91/pmc.h @@ -71,9 +71,11 @@ struct clk_pll_characteristics { }; struct clk_programmable_layout { + u8 pres_mask; u8 pres_shift; u8 css_mask; u8 have_slck_mck; + u8 is_pres_direct; }; extern const struct clk_programmable_layout at91rm9200_programmable_layout; diff --git a/drivers/clk/at91/sama5d2.c b/drivers/clk/at91/sama5d2.c index 1f70cb164b06..81943fac4537 100644 --- a/drivers/clk/at91/sama5d2.c +++ b/drivers/clk/at91/sama5d2.c @@ -125,6 +125,14 @@ static const struct { .pll = true }, }; +static const struct clk_programmable_layout sama5d2_programmable_layout = { + .pres_mask = 0xff, + .pres_shift = 4, + .css_mask = 0x7, + .have_slck_mck = 0, + .is_pres_direct = 1, +}; + static void __init sama5d2_pmc_setup(struct device_node *np) { struct clk_range range = CLK_RANGE(0, 0); @@ -249,7 +257,7 @@ static void __init sama5d2_pmc_setup(struct device_node *np) hw = at91_clk_register_programmable(regmap, name, parent_names, 6, i, - &at91sam9x5_programmable_layout); + &sama5d2_programmable_layout); if (IS_ERR(hw)) goto err_free; }