Hi Geert, Thank you for the review. On Thu, May 8, 2025 at 5:06 PM Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> wrote: > > Hi Prabhakar, > > On Mon, 28 Apr 2025 at 20:42, Prabhakar <prabhakar.csengg@xxxxxxxxx> wrote: > > From: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx> > > > > Introduce support for module clocks that may be sourced from an external > > clock rather than the on-chip PLL. Add two new fields `external_clk` and > > `external_clk_mux_index` to `struct rzv2h_mod_clk` and `struct mod_clock` > > to mark such clocks and record the mux index corresponding to the external > > input. > > > > Provide a new helper macro `DEF_MOD_MUX_EXTERNAL()` for concise declaration > > of external-source module clocks. > > > > In `rzv2h_mod_clock_is_enabled()`, detect when the parent mux selects the > > external source (by comparing the current mux index against > > `external_clk_mux_index`) and skip the normal CLK_MON register check in > > that case. Update `rzv2h_cpg_register_mod_clk()` to populate the new fields > > from the SoC info. > > > > Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx> > > --- > > v2->v3: > > - Renamed helper macro to `DEF_MOD_MUX_EXTERNAL()`. > > - Added a new field `external_clk_mux_index` to `struct mod_clock` to > > store the mux index corresponding to the external input. > > - Updated the `rzv2h_mod_clock_is_enabled()` function to check if the > > parent mux selects the external source by comparing the current mux > > index against `external_clk_mux_index`. > > - Updated the `rzv2h_cpg_register_mod_clk()` function to populate the new > > fields from the SoC info. > > - Updated commit description > > Thanks for the update! > > LGTM. But as I will not apply the second patch yet anyway, I am a > little bit more pedantic with my comments below (no offense intended, > though ;-) > No offense taken at all, I appreciate the thoroughness. I'll make the suggested adjustments :) > > --- a/drivers/clk/renesas/rzv2h-cpg.c > > +++ b/drivers/clk/renesas/rzv2h-cpg.c > > @@ -119,6 +119,8 @@ struct pll_clk { > > * @on_bit: ON/MON bit > > * @mon_index: monitor register offset > > * @mon_bit: monitor bit > > + * @external_clk: Boolean flag indicating whether the parent clock can be an external clock > > + * @external_clk_mux_index: Index of the clock mux selection when the source is an external clock > > */ > > struct mod_clock { > > struct rzv2h_cpg_priv *priv; > > @@ -129,6 +131,8 @@ struct mod_clock { > > u8 on_bit; > > s8 mon_index; > > u8 mon_bit; > > + bool external_clk; > > + u8 external_clk_mux_index; > > Perhaps combine these two fields into > > s8 ext_clk_mux_index; > > with -1 indicating not valid, cfr. mon_bit? > Good point. > > > }; > > > > #define to_mod_clock(_hw) container_of(_hw, struct mod_clock, hw) > > @@ -567,10 +571,33 @@ static int rzv2h_mod_clock_is_enabled(struct clk_hw *hw) > > { > > struct mod_clock *clock = to_mod_clock(hw); > > struct rzv2h_cpg_priv *priv = clock->priv; > > + bool skip_mon = false; > > u32 bitmask; > > u32 offset; > > > > - if (clock->mon_index >= 0) { > > + if (clock->mon_index >= 0 && clock->external_clk) { > > I think the first condition can be dropped, as clock->external_clk > implies a valid mon_index. > Agreed. > > + struct clk_hw *parent_hw; > > + struct clk *parent_clk; > > + struct clk_mux *mux; > > + int index; > > + u32 val; > > + > > + parent_clk = clk_get_parent(hw->clk); > > + if (IS_ERR(parent_clk)) > > Can this actually happen? > No, I will drop this and add a comment. > > + goto check_mon; > > + > > + parent_hw = __clk_get_hw(parent_clk); > > + mux = to_clk_mux(parent_hw); > > + > > + val = readl(mux->reg) >> mux->shift; > > + val &= mux->mask; > > + index = clk_mux_val_to_index(parent_hw, mux->table, 0, val); > > + if (index == clock->external_clk_mux_index) > > + skip_mon = true; > > + } > > + > > +check_mon: > > + if (clock->mon_index >= 0 && !skip_mon) { > > offset = GET_CLK_MON_OFFSET(clock->mon_index); > > bitmask = BIT(clock->mon_bit); > > > > I am not so fond of the goto and the !skip_mon logic, and wonder > if we can improve? Perhaps spin of the index obtaining logic into a > parent_clk_mux_index() helper, and something like: > Ok, I'll add a helper rzv2h_clk_mux_to_index(). > int mon_index = clock->mon_index; > > if (clock->external_clk) { > if (parent_clk_mux_index(hw) == clock->external_clk_mux_index)) > mon_index = -1; > } > > if (mon_index >= 0) { > // do it > } > Agreed, with this we can get rid of goto. > > --- a/drivers/clk/renesas/rzv2h-cpg.h > > +++ b/drivers/clk/renesas/rzv2h-cpg.h > > @@ -192,6 +192,8 @@ enum clk_types { > > * @on_bit: ON bit > > * @mon_index: monitor register index > > * @mon_bit: monitor bit > > + * @external_clk: Boolean flag indicating whether the parent clock can be an external clock > > + * @external_clk_mux_index: Index of the clock mux selection when the source is an external clock > > */ > > struct rzv2h_mod_clk { > > const char *name; > > @@ -203,9 +205,12 @@ struct rzv2h_mod_clk { > > u8 on_bit; > > s8 mon_index; > > u8 mon_bit; > > + bool external_clk; > > + u8 external_clk_mux_index; > > s8 ext_clk_mux_index > OK. Cheers, Prabhakar