From d539efa37f1f789339699c941e72e320d12d5f28 Mon Sep 17 00:00:00 2001 From: Tero Kristo Date: Fri, 3 Oct 2014 16:57:11 +0300 Subject: [PATCH] ARM: OMAP3: clock: add new rate changing logic support for noncore DPLLs Currently, DPLL code hides the re-parenting within its internals, which is wrong. This needs to be exposed to the common clock code via determine_rate and set_rate_and_parent APIs. This patch adds support for these, which will be taken into use in the following patches. Signed-off-by: Tero Kristo Signed-off-by: Paul Walmsley --- arch/arm/mach-omap2/dpll3xxx.c | 147 +++++++++++++++++++++++++++++++++ include/linux/clk/ti.h | 9 ++ 2 files changed, 156 insertions(+) diff --git a/arch/arm/mach-omap2/dpll3xxx.c b/arch/arm/mach-omap2/dpll3xxx.c index ac3d789ac3cd..cfe7c30235d1 100644 --- a/arch/arm/mach-omap2/dpll3xxx.c +++ b/arch/arm/mach-omap2/dpll3xxx.c @@ -546,6 +546,153 @@ int omap3_noncore_dpll_set_rate(struct clk_hw *hw, unsigned long rate, return 0; } +/** + * omap3_noncore_dpll_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 target 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 omap3_noncore_dpll_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 = omap2_dpll_round_rate(hw, rate, best_parent_rate); + *best_parent_clk = dd->clk_ref; + } + + *best_parent_rate = rate; + + return rate; +} + +/** + * omap3_noncore_dpll_set_parent - set parent for a DPLL clock + * @hw: pointer to the clock to set parent for + * @index: parent index to select + * + * Sets parent for a DPLL clock. This sets the DPLL into bypass or + * locked mode. Returns 0 with success, negative error value otherwise. + */ +int omap3_noncore_dpll_set_parent(struct clk_hw *hw, u8 index) +{ + struct clk_hw_omap *clk = to_clk_hw_omap(hw); + int ret; + + if (!hw) + return -EINVAL; + + if (index) + ret = _omap3_noncore_dpll_bypass(clk); + else + ret = _omap3_noncore_dpll_lock(clk); + + return ret; +} + +/** + * omap3_noncore_dpll_set_rate_new - set rate for a DPLL clock + * @hw: pointer to the clock to set parent for + * @rate: target rate for the clock + * @parent_rate: rate of the parent clock + * + * Sets rate for a DPLL clock. First checks if the clock parent is + * reference clock (in bypass mode, the rate of the clock can't be + * changed) and proceeds with the rate change operation. Returns 0 + * with success, negative error value otherwise. + */ +static int omap3_noncore_dpll_set_rate_new(struct clk_hw *hw, + unsigned long rate, + unsigned long parent_rate) +{ + struct clk_hw_omap *clk = to_clk_hw_omap(hw); + struct dpll_data *dd; + u16 freqsel = 0; + int ret; + + if (!hw || !rate) + return -EINVAL; + + dd = clk->dpll_data; + if (!dd) + return -EINVAL; + + if (__clk_get_parent(hw->clk) != dd->clk_ref) + return -EINVAL; + + if (dd->last_rounded_rate == 0) + return -EINVAL; + + /* Freqsel is available only on OMAP343X devices */ + if (ti_clk_features.flags & TI_CLK_DPLL_HAS_FREQSEL) { + freqsel = _omap3_dpll_compute_freqsel(clk, dd->last_rounded_n); + WARN_ON(!freqsel); + } + + pr_debug("%s: %s: set rate: locking rate to %lu.\n", __func__, + __clk_get_name(hw->clk), rate); + + ret = omap3_noncore_dpll_program(clk, freqsel); + + return ret; +} + +/** + * omap3_noncore_dpll_set_rate_and_parent - set rate and parent for a DPLL clock + * @hw: pointer to the clock to set rate and parent for + * @rate: target rate for the DPLL + * @parent_rate: clock rate of the DPLL parent + * @index: new parent index for the DPLL, 0 - reference, 1 - bypass + * + * Sets rate and parent for a DPLL clock. If new parent is the bypass + * clock, only selects the parent. Otherwise proceeds with a rate + * change, as this will effectively also change the parent as the + * DPLL is put into locked mode. Returns 0 with success, negative error + * value otherwise. + */ +int omap3_noncore_dpll_set_rate_and_parent(struct clk_hw *hw, + unsigned long rate, + unsigned long parent_rate, + u8 index) +{ + int ret; + + if (!hw || !rate) + return -EINVAL; + + /* + * clk-ref at index[0], in which case we only need to set rate, + * the parent will be changed automatically with the lock sequence. + * With clk-bypass case we only need to change parent. + */ + if (index) + ret = omap3_noncore_dpll_set_parent(hw, index); + else + ret = omap3_noncore_dpll_set_rate_new(hw, rate, parent_rate); + + return ret; +} + /* DPLL autoidle read/set code */ /** diff --git a/include/linux/clk/ti.h b/include/linux/clk/ti.h index f75acbf70e96..6f9fb77ffdd5 100644 --- a/include/linux/clk/ti.h +++ b/include/linux/clk/ti.h @@ -254,8 +254,17 @@ extern const struct clk_ops ti_clk_mux_ops; void omap2_init_clk_hw_omap_clocks(struct clk *clk); int omap3_noncore_dpll_enable(struct clk_hw *hw); void omap3_noncore_dpll_disable(struct clk_hw *hw); +int omap3_noncore_dpll_set_parent(struct clk_hw *hw, u8 index); int omap3_noncore_dpll_set_rate(struct clk_hw *hw, unsigned long rate, unsigned long parent_rate); +int omap3_noncore_dpll_set_rate_and_parent(struct clk_hw *hw, + unsigned long rate, + unsigned long parent_rate, + u8 index); +long omap3_noncore_dpll_determine_rate(struct clk_hw *hw, + unsigned long rate, + unsigned long *best_parent_rate, + struct clk **best_parent_clk); unsigned long omap4_dpll_regm4xen_recalc(struct clk_hw *hw, unsigned long parent_rate); long omap4_dpll_regm4xen_round_rate(struct clk_hw *hw,