diff --git a/arch/arm/mach-omap2/dpll44xx.c b/arch/arm/mach-omap2/dpll44xx.c index 4613f1e86988751072826fb549a0f920d7df25e8..535822fcf4bbbd1e57a1211d122449d0a8a5807d 100644 --- a/arch/arm/mach-omap2/dpll44xx.c +++ b/arch/arm/mach-omap2/dpll44xx.c @@ -207,3 +207,44 @@ long omap4_dpll_regm4xen_round_rate(struct clk_hw *hw, return dd->last_rounded_rate; } + +/** + * omap4_dpll_regm4xen_determine_rate - determine rate for a DPLL + * @hw: pointer to the clock to determine rate for + * @rate: target rate for the DPLL + * @best_parent_rate: pointer for returning best parent rate + * @best_parent_clk: pointer for returning best parent clock + * + * Determines which DPLL mode to use for reaching a desired rate. + * Checks whether the DPLL shall be in bypass or locked mode, and if + * locked, calculates the M,N values for the DPLL via round-rate. + * Returns a positive clock rate with success, negative error value + * in failure. + */ +long omap4_dpll_regm4xen_determine_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *best_parent_rate, + struct clk **best_parent_clk) +{ + struct clk_hw_omap *clk = to_clk_hw_omap(hw); + struct dpll_data *dd; + + if (!hw || !rate) + return -EINVAL; + + dd = clk->dpll_data; + if (!dd) + return -EINVAL; + + if (__clk_get_rate(dd->clk_bypass) == rate && + (dd->modes & (1 << DPLL_LOW_POWER_BYPASS))) { + *best_parent_clk = dd->clk_bypass; + } else { + rate = omap4_dpll_regm4xen_round_rate(hw, rate, + best_parent_rate); + *best_parent_clk = dd->clk_ref; + } + + *best_parent_rate = rate; + + return rate; +} diff --git a/include/linux/clk/ti.h b/include/linux/clk/ti.h index 6f9fb77ffdd553187f844a4e7bd6e13ae54d1ea7..abc702a73aca453d34ca7e3100fec150655c006f 100644 --- a/include/linux/clk/ti.h +++ b/include/linux/clk/ti.h @@ -270,6 +270,10 @@ unsigned long omap4_dpll_regm4xen_recalc(struct clk_hw *hw, long omap4_dpll_regm4xen_round_rate(struct clk_hw *hw, unsigned long target_rate, unsigned long *parent_rate); +long omap4_dpll_regm4xen_determine_rate(struct clk_hw *hw, + unsigned long rate, + unsigned long *best_parent_rate, + struct clk **best_parent_clk); u8 omap2_init_dpll_parent(struct clk_hw *hw); unsigned long omap3_dpll_recalc(struct clk_hw *hw, unsigned long parent_rate); long omap2_dpll_round_rate(struct clk_hw *hw, unsigned long target_rate,