This is address in the V2: https://patchwork.kernel.org/patch/10144477/ > -----Original Message----- > From: Julien Thierry [mailto:julien.thierry@xxxxxxx] > Sent: Tuesday, December 12, 2017 5:06 PM > To: Ilia Lin <ilialin@xxxxxxxxxxxxxx>; linux-clk@xxxxxxxxxxxxxxx; linux-arm- > kernel@xxxxxxxxxxxxxxxxxxx; linux-arm-msm@xxxxxxxxxxxxxxx; > sboyd@xxxxxxxxxxxxxx > Cc: mark.rutland@xxxxxxx; devicetree@xxxxxxxxxxxxxxx; > rnayak@xxxxxxxxxxxxxx; will.deacon@xxxxxxx; tfinkel@xxxxxxxxxxxxxx; > qualcomm-lt@xxxxxxxxxxxxxxxx; celster@xxxxxxxxxxxxxx; Taniya Das > <tdas@xxxxxxxxxxxxxx> > Subject: Re: [PATCH 02/10] clk: qcom: Fix .set_rate to handle alpha PLLs > w/wo dynamic update > > Hi, > > On 12/12/17 12:31, Ilia Lin wrote: > > From: Taniya Das <tdas@xxxxxxxxxxxxxx> > > > > From: Taniya Das <tdas@xxxxxxxxxxxxxx> > > > > Alpha PLLs which do not support dynamic update feature need to be > > explicitly disabled before a rate change. > > The ones which do support dynamic update do so within a single vco > > range, so add a min/max freq check for such PLLs so they fall in the > > vco range. > > > > Signed-off-by: Taniya Das <tdas@xxxxxxxxxxxxxx> > > Signed-off-by: Rajendra Nayak <rnayak@xxxxxxxxxxxxxx> > > Signed-off-by: Ilia Lin <ilialin@xxxxxxxxxxxxxx> > > --- > > drivers/clk/qcom/clk-alpha-pll.c | 71 > +++++++++++++++++++++++++++++++++------- > > drivers/clk/qcom/clk-alpha-pll.h | 5 +++ > > 2 files changed, 65 insertions(+), 11 deletions(-) > > > > diff --git a/drivers/clk/qcom/clk-alpha-pll.c > > b/drivers/clk/qcom/clk-alpha-pll.c > > index 47a1da3..ecb9e7f 100644 > > --- a/drivers/clk/qcom/clk-alpha-pll.c > > +++ b/drivers/clk/qcom/clk-alpha-pll.c > > @@ -376,19 +376,46 @@ static unsigned long alpha_pll_calc_rate(u64 > prate, u32 l, u32 a) > > return alpha_pll_calc_rate(prate, l, a); > > } > > > > -static int clk_alpha_pll_set_rate(struct clk_hw *hw, unsigned long rate, > > - unsigned long prate) > > +static int alpha_pll_set_rate(struct clk_hw *hw, unsigned long rate, > > + unsigned long prate, > > + int (*enable)(struct clk_hw *hw), > > + void (*disable)(struct clk_hw *hw)) > > { > > + bool enabled; > > Some remarks about this. > > > struct clk_alpha_pll *pll = to_clk_alpha_pll(hw); > > const struct pll_vco *vco; > > u32 l, off = pll->offset; > > u64 a; > > > > rate = alpha_pll_round_rate(rate, prate, &l, &a); > > - vco = alpha_pll_find_vco(pll, rate); > > - if (!vco) { > > - pr_err("alpha pll not in a valid vco range\n"); > > - return -EINVAL; > > + enabled = clk_hw_is_enabled(hw); > > This is not needed unless we go through the 'else' branch. > > > + > > + if (pll->flags & SUPPORTS_DYNAMIC_UPDATE) { > > + /* > > + * PLLs which support dynamic updates support one single > > + * vco range, between min_rate and max_rate supported > > + */ > > + if (rate < pll->min_rate || rate > pll->max_rate) { > > + pr_err("alpha pll rate outside supported min/max > range\n"); > > + return -EINVAL; > > + } > > + } else { > > + /* > > + * All alpha PLLs which do not support dynamic update, > > + * should be disabled before a vco update. > > + */ > > + if (enabled) > > + disable(hw); > > + > > + vco = alpha_pll_find_vco(pll, rate); > > + if (!vco) { > > + pr_err("alpha pll not in a valid vco range\n"); > > + return -EINVAL; > > + } > > + > > + regmap_update_bits(pll->clkr.regmap, off + PLL_USER_CTL, > > + PLL_VCO_MASK << PLL_VCO_SHIFT, > > + vco->val << PLL_VCO_SHIFT); > > } > > > > regmap_write(pll->clkr.regmap, off + PLL_L_VAL, l); @@ -401,16 > > +428,29 @@ static int clk_alpha_pll_set_rate(struct clk_hw *hw, unsigned > long rate, > > regmap_write(pll->clkr.regmap, off + PLL_ALPHA_VAL_U, a > >> 32); > > } > > > > - regmap_update_bits(pll->clkr.regmap, off + PLL_USER_CTL, > > - PLL_VCO_MASK << PLL_VCO_SHIFT, > > - vco->val << PLL_VCO_SHIFT); > > - > > regmap_update_bits(pll->clkr.regmap, off + PLL_USER_CTL, > PLL_ALPHA_EN, > > PLL_ALPHA_EN); > > > > + if (!(pll->flags & SUPPORTS_DYNAMIC_UPDATE) && enabled) > > + enable(hw); > > + > > This condition is only "did we disable the clock and need to reenable it?". > > To make it clearer, I'd suggest renaming 'enabled' to something like > 'need_reenabling' and the code look like this: > > static int alpha_pll_set_rate(struct clk_hw *hw, unsigned long rate, > unsigned long prate, > int (*enable)(struct clk_hw *hw), > void (*disable)(struct clk_hw *hw)) { > bool need_reenabling = false; > > [...] > > if(pll->flags & SUPPORTS_DYNAMIC_UPDATE) { > [...] > } else { > if (clk_hw_is_enabled(hw)) { > disable(hw); > need_reenabling = true; > } > [...] > } > > [...] > > if (need_reenabling) > enable(hw); > > } > > > Cheers, > > -- > Julien Thierry -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
