Hi Sascha, On 4 March 2015 at 19:21, Sascha Hauer <s.hauer@xxxxxxxxxxxxxx> wrote: > On Wed, Mar 04, 2015 at 06:49:11PM +0800, pi-cheng.chen wrote: >> This patch adds CPU mux clocks which are used by Mediatek cpufreq driver >> for intermediate clock source switching. This patch is based on Mediatek >> clock driver patches[1]. >> >> [1] http://thread.gmane.org/gmane.linux.kernel/1892436 >> >> Signed-off-by: pi-cheng.chen <pi-cheng.chen@xxxxxxxxxx> >> --- >> +static long clk_cpumux_determine_rate(struct clk_hw *hw, unsigned long rate, >> + unsigned long min_rate, >> + unsigned long max_rate, >> + unsigned long *best_parent_rate, >> + struct clk_hw **best_parent_p) >> +{ >> + struct clk *clk = hw->clk, *parent; >> + unsigned long parent_rate; >> + int i; >> + >> + for (i = MAINPLL_INDEX; i >= ARMPLL_INDEX; i--) { >> + parent = clk_get_parent_by_index(clk, i); >> + if (!parent) >> + return 0; >> + >> + if (i == MAINPLL_INDEX) { >> + parent_rate = __clk_get_rate(parent); >> + if (parent_rate == rate) >> + break; >> + } >> + >> + parent_rate = __clk_round_rate(parent, rate); >> + } >> + >> + *best_parent_rate = parent_rate; >> + *best_parent_p = __clk_get_hw(parent); >> + return parent_rate; >> +} > > Why this determine_rate hook? If you want to switch the clock to some > intermediate parent I would assume you do this explicitly by setting the > parent and not implicitly by setting a rate. > I use determine_rate hook here because I am using generic cpufreq-dt driver and I want to make clock switching transparent to cpufreq-dt. I.e. when I am trying to switch the clock from ARMPLL to MAINPLL, I call clk_set_rate() with the rate of MAINPLL, and determine_rate will select MAINPLL as the new parent. >> +int mtk_clk_register_cpumuxes(struct device_node *node, >> + struct mtk_composite *clks, int num, >> + struct clk_onecell_data *clk_data) >> +{ >> + int i; >> + struct clk *clk; >> + struct regmap *regmap; >> + >> + if (!clk_data) >> + return -ENOMEM; >> + >> + regmap = syscon_node_to_regmap(node); >> + if (IS_ERR(regmap)) { >> + pr_err("Cannot find regmap for %s: %ld\n", node->full_name, >> + PTR_ERR(regmap)); >> + return PTR_ERR(regmap); >> + } >> + >> + for (i = 0; i < num; i++) { >> + struct mtk_composite *mux = &clks[i]; >> + >> + clk = mtk_clk_register_cpumux(mux->name, mux->parent_names, >> + mux->num_parents, regmap, >> + mux->mux_reg, mux->mux_shift, >> + mux->mux_width); > > Pass 'mux' directly instead of dispatching this struct into the > individual fields. > Also, probably better to move this function to > drivers/clk/mediatek/clk-cpumux.c Will do it. Thanks for reviewing. Best Regards, Pi-Cheng > > Sascha > > -- > Pengutronix e.K. | | > Industrial Linux Solutions | http://www.pengutronix.de/ | > Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | > Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | -- 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
