From patchwork Thu Jun 6 07:28:32 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Simon Horman X-Patchwork-Id: 2677631 Return-Path: X-Original-To: patchwork-linux-sh@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork2.kernel.org (Postfix) with ESMTP id C5F70DFE82 for ; Thu, 6 Jun 2013 07:28:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757393Ab3FFH2x (ORCPT ); Thu, 6 Jun 2013 03:28:53 -0400 Received: from kirsty.vergenet.net ([202.4.237.240]:59369 "EHLO kirsty.vergenet.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757076Ab3FFH2p (ORCPT ); Thu, 6 Jun 2013 03:28:45 -0400 Received: from ayumi.isobedori.kobe.vergenet.net (p5212-ipbfp1903kobeminato.hyogo.ocn.ne.jp [114.172.132.212]) by kirsty.vergenet.net (Postfix) with ESMTP id 7F16425C058; Thu, 6 Jun 2013 17:28:43 +1000 (EST) Received: by ayumi.isobedori.kobe.vergenet.net (Postfix, from userid 7100) id 2BB0D6CE345; Thu, 6 Jun 2013 16:28:41 +0900 (JST) From: Simon Horman To: Arnd Bergmann , Olof Johansson Cc: linux-sh@vger.kernel.org, arm@kernel.org, linux-arm-kernel@lists.infradead.org, Magnus Damm , Guennadi Liakhovetski , Guennadi Liakhovetski , Simon Horman Subject: [PATCH 19/23] ARM: shmobile: sh73a0: add support for adjusting CPU frequency Date: Thu, 6 Jun 2013 16:28:32 +0900 Message-Id: <1370503716-31155-20-git-send-email-horms+renesas@verge.net.au> X-Mailer: git-send-email 1.8.2.1 In-Reply-To: <1370503716-31155-1-git-send-email-horms+renesas@verge.net.au> References: <1370503716-31155-1-git-send-email-horms+renesas@verge.net.au> Sender: linux-sh-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sh@vger.kernel.org From: Guennadi Liakhovetski On SH73A0 the output of PLL0 is supplied to two dividers, feeding clock to the CPU core and SGX. Lower CPU frequencies allow the use of lower supply voltages and thus reduce power consumption. Signed-off-by: Guennadi Liakhovetski Signed-off-by: Simon Horman --- arch/arm/mach-shmobile/clock-sh73a0.c | 95 ++++++++++++++++++++++++++++++++++- 1 file changed, 93 insertions(+), 2 deletions(-) diff --git a/arch/arm/mach-shmobile/clock-sh73a0.c b/arch/arm/mach-shmobile/clock-sh73a0.c index 784fbaa..acb9e09 100644 --- a/arch/arm/mach-shmobile/clock-sh73a0.c +++ b/arch/arm/mach-shmobile/clock-sh73a0.c @@ -228,6 +228,11 @@ enum { DIV4_I, DIV4_ZG, DIV4_M3, DIV4_B, DIV4_M1, DIV4_M2, static struct clk div4_clks[DIV4_NR] = { [DIV4_I] = DIV4(FRQCRA, 20, 0xdff, CLK_ENABLE_ON_INIT), + /* + * ZG clock is dividing PLL0 frequency to supply SGX. Make sure not to + * exceed maximum frequencies of 201.5MHz for VDD_DVFS=1.175 and + * 239.2MHz for VDD_DVFS=1.315V. + */ [DIV4_ZG] = SH_CLK_DIV4(&pll0_clk, FRQCRA, 16, 0xd7f, CLK_ENABLE_ON_INIT), [DIV4_M3] = DIV4(FRQCRA, 12, 0x1dff, CLK_ENABLE_ON_INIT), [DIV4_B] = DIV4(FRQCRA, 8, 0xdff, CLK_ENABLE_ON_INIT), @@ -252,6 +257,85 @@ static struct clk twd_clk = { .ops = &twd_clk_ops, }; +static int (*div4_set_rate)(struct clk *clk, unsigned long rate); +static unsigned long (*div4_recalc)(struct clk *clk); +static long (*div4_round_rate)(struct clk *clk, unsigned long rate); + +static int zclk_set_rate(struct clk *clk, unsigned long rate) +{ + int ret; + + if (!clk->parent || !__clk_get(clk->parent)) + return -ENODEV; + + if (readl(FRQCRB) & (1 << 31)) + return -EBUSY; + + if (rate == clk_get_rate(clk->parent)) { + /* 1:1 - switch off divider */ + __raw_writel(__raw_readl(FRQCRB) & ~(1 << 28), FRQCRB); + /* nullify the divider to prepare for the next time */ + ret = div4_set_rate(clk, rate / 2); + if (!ret) + ret = frqcr_kick(); + if (ret > 0) + ret = 0; + } else { + /* Enable the divider */ + __raw_writel(__raw_readl(FRQCRB) | (1 << 28), FRQCRB); + + ret = frqcr_kick(); + if (ret >= 0) + /* + * set the divider - call the DIV4 method, it will kick + * FRQCRB too + */ + ret = div4_set_rate(clk, rate); + if (ret < 0) + goto esetrate; + } + +esetrate: + __clk_put(clk->parent); + return ret; +} + +static long zclk_round_rate(struct clk *clk, unsigned long rate) +{ + unsigned long div_freq = div4_round_rate(clk, rate), + parent_freq = clk_get_rate(clk->parent); + + if (rate > div_freq && abs(parent_freq - rate) < rate - div_freq) + return parent_freq; + + return div_freq; +} + +static unsigned long zclk_recalc(struct clk *clk) +{ + /* + * Must recalculate frequencies in case PLL0 has been changed, even if + * the divisor is unused ATM! + */ + unsigned long div_freq = div4_recalc(clk); + + if (__raw_readl(FRQCRB) & (1 << 28)) + return div_freq; + + return clk_get_rate(clk->parent); +} + +static void zclk_extend(void) +{ + /* We extend the DIV4 clock with a 1:1 pass-through case */ + div4_set_rate = div4_clks[DIV4_Z].ops->set_rate; + div4_round_rate = div4_clks[DIV4_Z].ops->round_rate; + div4_recalc = div4_clks[DIV4_Z].ops->recalc; + div4_clks[DIV4_Z].ops->set_rate = zclk_set_rate; + div4_clks[DIV4_Z].ops->round_rate = zclk_round_rate; + div4_clks[DIV4_Z].ops->recalc = zclk_recalc; +} + enum { DIV6_VCK1, DIV6_VCK2, DIV6_VCK3, DIV6_ZB1, DIV6_FLCTL, DIV6_SDHI0, DIV6_SDHI1, DIV6_SDHI2, DIV6_FSIA, DIV6_FSIB, DIV6_SUB, @@ -450,7 +534,7 @@ static struct clk *late_main_clks[] = { }; enum { MSTP001, - MSTP129, MSTP128, MSTP127, MSTP126, MSTP125, MSTP118, MSTP116, MSTP100, + MSTP129, MSTP128, MSTP127, MSTP126, MSTP125, MSTP118, MSTP116, MSTP112, MSTP100, MSTP219, MSTP218, MSTP217, MSTP207, MSTP206, MSTP204, MSTP203, MSTP202, MSTP201, MSTP200, MSTP331, MSTP329, MSTP328, MSTP325, MSTP323, MSTP322, @@ -471,6 +555,7 @@ static struct clk mstp_clks[MSTP_NR] = { [MSTP125] = MSTP(&div6_clks[DIV6_SUB], SMSTPCR1, 25, 0), /* TMU0 */ [MSTP118] = MSTP(&div4_clks[DIV4_B], SMSTPCR1, 18, 0), /* DSITX0 */ [MSTP116] = MSTP(&div4_clks[DIV4_HP], SMSTPCR1, 16, 0), /* IIC0 */ + [MSTP112] = MSTP(&div4_clks[DIV4_ZG], SMSTPCR1, 12, 0), /* SGX */ [MSTP100] = MSTP(&div4_clks[DIV4_B], SMSTPCR1, 0, 0), /* LCDC0 */ [MSTP219] = MSTP(&div6_clks[DIV6_SUB], SMSTPCR2, 19, 0), /* SCIFA7 */ [MSTP218] = MSTP(&div4_clks[DIV4_HP], SMSTPCR2, 18, 0), /* SY-DMAC */ @@ -513,6 +598,9 @@ static struct clk_lookup lookups[] = { CLKDEV_CON_ID("r_clk", &r_clk), CLKDEV_DEV_ID("smp_twd", &twd_clk), /* smp_twd */ + /* DIV4 clocks */ + CLKDEV_DEV_ID("cpufreq-cpu0", &div4_clks[DIV4_Z]), + /* DIV6 clocks */ CLKDEV_CON_ID("vck1_clk", &div6_clks[DIV6_VCK1]), CLKDEV_CON_ID("vck2_clk", &div6_clks[DIV6_VCK2]), @@ -604,8 +692,11 @@ void __init sh73a0_clock_init(void) for (k = 0; !ret && (k < ARRAY_SIZE(main_clks)); k++) ret = clk_register(main_clks[k]); - if (!ret) + if (!ret) { ret = sh_clk_div4_register(div4_clks, DIV4_NR, &div4_table); + if (!ret) + zclk_extend(); + } if (!ret) ret = sh_clk_div6_reparent_register(div6_clks, DIV6_NR);