From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paul Walmsley Subject: [PATCH C 06/13] OMAP3 clock: DPLLs should enter bypass if new rate is sys_ck Date: Wed, 28 Jan 2009 12:08:26 -0700 Message-ID: <20090128190823.12092.2638.stgit@localhost.localdomain> References: <20090128190724.12092.22239.stgit@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Return-path: Received: from utopia.booyaka.com ([72.9.107.138]:60394 "EHLO utopia.booyaka.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751857AbZA1UZP (ORCPT ); Wed, 28 Jan 2009 15:25:15 -0500 In-Reply-To: <20090128190724.12092.22239.stgit@localhost.localdomain> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: linux-arm-kernel@lists.arm.linux.org.uk, linux-kernel@vger.kernel.org Cc: linux-omap@vger.kernel.org, Paul Walmsley , Tony Lindgren This patch causes a DPLL to enter bypass when it is instructed to set its rate to that of its bypass clock. Previously this was only possible after setting the DPLL rate, then disabling and re-enabling it. linux-omap source commit is 9c909ac90902a9c0ecca2bc9ac36289cb84990f5. Signed-off-by: Paul Walmsley Signed-off-by: Tony Lindgren --- arch/arm/mach-omap2/clock34xx.c | 40 ++++++++++++++++++++++++++++----------- 1 files changed, 29 insertions(+), 11 deletions(-) diff --git a/arch/arm/mach-omap2/clock34xx.c b/arch/arm/mach-omap2/clock34xx.c index c5efd7e..0f058c3 100644 --- a/arch/arm/mach-omap2/clock34xx.c +++ b/arch/arm/mach-omap2/clock34xx.c @@ -371,13 +371,17 @@ static int omap3_noncore_dpll_program(struct clk *clk, u16 m, u8 n, u16 freqsel) * @clk: struct clk * of DPLL to set * @rate: rounded target rate * - * Program the DPLL with the rounded target rate. Returns -EINVAL upon - * error, or 0 upon success. + * Set the DPLL CLKOUT to the target rate. If the DPLL can enter + * low-power bypass, and the target rate is the bypass source clock + * rate, then configure the DPLL for bypass. Otherwise, round the + * target rate if it hasn't been done already, then program and lock + * the DPLL. Returns -EINVAL upon error, or 0 upon success. */ static int omap3_noncore_dpll_set_rate(struct clk *clk, unsigned long rate) { u16 freqsel; struct dpll_data *dd; + int ret; if (!clk || !rate) return -EINVAL; @@ -389,18 +393,32 @@ static int omap3_noncore_dpll_set_rate(struct clk *clk, unsigned long rate) if (rate == omap2_get_dpll_rate(clk)) return 0; - if (dd->last_rounded_rate != rate) - omap2_dpll_round_rate(clk, rate); + if (dd->bypass_clk->rate == rate && + (clk->dpll_data->modes & (1 << DPLL_LOW_POWER_BYPASS))) { - if (dd->last_rounded_rate == 0) - return -EINVAL; + pr_debug("clock: %s: set rate: entering bypass.\n", clk->name); + + ret = _omap3_noncore_dpll_bypass(clk); + + } else { + + if (dd->last_rounded_rate != rate) + omap2_dpll_round_rate(clk, rate); - freqsel = _omap3_dpll_compute_freqsel(clk, dd->last_rounded_n); - if (!freqsel) - WARN_ON(1); + if (dd->last_rounded_rate == 0) + return -EINVAL; - omap3_noncore_dpll_program(clk, dd->last_rounded_m, dd->last_rounded_n, - freqsel); + freqsel = _omap3_dpll_compute_freqsel(clk, dd->last_rounded_n); + if (!freqsel) + WARN_ON(1); + + pr_debug("clock: %s: set rate: locking rate to %lu.\n", + clk->name, rate); + + ret = omap3_noncore_dpll_program(clk, dd->last_rounded_m, + dd->last_rounded_n, freqsel); + + } omap3_dpll_recalc(clk);