From patchwork Tue Jun 2 01:47:58 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stephen Boyd X-Patchwork-Id: 6526291 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 02DEFC0020 for ; Tue, 2 Jun 2015 01:51:26 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 033C720394 for ; Tue, 2 Jun 2015 01:51:25 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id C10C520384 for ; Tue, 2 Jun 2015 01:51:23 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1YzbKQ-0003GR-Ge; Tue, 02 Jun 2015 01:49:18 +0000 Received: from smtp.codeaurora.org ([198.145.29.96]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1YzbJr-0002wd-Rp for linux-arm-kernel@lists.infradead.org; Tue, 02 Jun 2015 01:48:45 +0000 Received: from smtp.codeaurora.org (localhost [127.0.0.1]) by smtp.codeaurora.org (Postfix) with ESMTP id 13AFB14085C; Tue, 2 Jun 2015 01:48:03 +0000 (UTC) Received: by smtp.codeaurora.org (Postfix, from userid 486) id 04C9C140868; Tue, 2 Jun 2015 01:48:03 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 Received: from sboyd-linux.qualcomm.com (i-global254.qualcomm.com [199.106.103.254]) (using TLSv1.1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) (Authenticated sender: sboyd@smtp.codeaurora.org) by smtp.codeaurora.org (Postfix) with ESMTPSA id 3E3A714085C; Tue, 2 Jun 2015 01:48:02 +0000 (UTC) From: Stephen Boyd To: linux-arm-msm@vger.kernel.org Subject: [PATCH 5/6] cpufreq-dt: Handle OPP voltage adjust events Date: Mon, 1 Jun 2015 18:47:58 -0700 Message-Id: <1433209679-31389-6-git-send-email-sboyd@codeaurora.org> X-Mailer: git-send-email 2.3.0.rc1.33.g42e4583 In-Reply-To: <1433209679-31389-1-git-send-email-sboyd@codeaurora.org> References: <1433209679-31389-1-git-send-email-sboyd@codeaurora.org> X-Virus-Scanned: ClamAV using ClamSMTP X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20150601_184843_956955_F2615790 X-CRM114-Status: GOOD ( 19.97 ) X-Spam-Score: -0.0 (/) Cc: Nishanth Menon , David Collins , linux-pm@vger.kernel.org, Viresh Kumar , linux-kernel@vger.kernel.org, Mark Brown , Srinivas Kandagatla , Andy Gross , linux-arm-kernel@lists.infradead.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP On some SoCs the Adaptive Voltage Scaling (AVS) technique is employed to optimize the operating voltage of a device. At a given frequency, the hardware monitors dynamic factors and either makes a suggestion for how much to adjust a voltage for the current frequency, or it automatically adjusts the voltage without software intervention. In the former case, an AVS driver will call dev_pm_opp_modify_voltage() and update the voltage for the particular OPP the CPUs are using. Add an OPP notifier to cpufreq-dt so that we can adjust the voltage of the CPU when AVS updates the OPP. Signed-off-by: Stephen Boyd --- drivers/cpufreq/cpufreq-dt.c | 73 ++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 67 insertions(+), 6 deletions(-) diff --git a/drivers/cpufreq/cpufreq-dt.c b/drivers/cpufreq/cpufreq-dt.c index bab67db54b7e..616218f133be 100644 --- a/drivers/cpufreq/cpufreq-dt.c +++ b/drivers/cpufreq/cpufreq-dt.c @@ -34,8 +34,48 @@ struct private_data { struct regulator *cpu_reg; struct thermal_cooling_device *cdev; unsigned int voltage_tolerance; /* in percentage */ + struct notifier_block opp_nb; + struct mutex lock; + unsigned long opp_freq; }; + +static int opp_notifier(struct notifier_block *nb, unsigned long event, + void *data) +{ + struct dev_pm_opp *opp = data; + struct private_data *priv = container_of(nb, struct private_data, + opp_nb); + struct device *cpu_dev = priv->cpu_dev; + struct regulator *cpu_reg = priv->cpu_reg; + unsigned long volt, tol, freq; + int ret = 0; + + switch (event) { + case OPP_EVENT_ADJUST_VOLTAGE: + volt = dev_pm_opp_get_voltage(opp); + freq = dev_pm_opp_get_freq(opp); + tol = volt * priv->voltage_tolerance / 100; + + mutex_lock(&priv->lock); + if (freq == priv->opp_freq) + ret = regulator_set_voltage_tol(cpu_reg, volt, + tol); + mutex_unlock(&priv->lock); + if (ret) { + dev_err(cpu_dev, + "failed to scale voltage up: %d\n", + ret); + return ret; + } + break; + default: + break; + } + + return 0; +} + static int set_target(struct cpufreq_policy *policy, unsigned int index) { struct dev_pm_opp *opp; @@ -47,6 +87,7 @@ static int set_target(struct cpufreq_policy *policy, unsigned int index) unsigned long volt = 0, volt_old = 0, tol = 0; unsigned int old_freq, new_freq; long freq_Hz, freq_exact; + unsigned long opp_freq = 0; int ret; freq_Hz = clk_round_rate(cpu_clk, freq_table[index].frequency * 1000); @@ -57,8 +98,8 @@ static int set_target(struct cpufreq_policy *policy, unsigned int index) new_freq = freq_Hz / 1000; old_freq = clk_get_rate(cpu_clk) / 1000; + mutex_lock(&priv->lock); if (!IS_ERR(cpu_reg)) { - unsigned long opp_freq; rcu_read_lock(); opp = dev_pm_opp_find_freq_ceil(cpu_dev, &freq_Hz); @@ -66,7 +107,8 @@ static int set_target(struct cpufreq_policy *policy, unsigned int index) rcu_read_unlock(); dev_err(cpu_dev, "failed to find OPP for %ld\n", freq_Hz); - return PTR_ERR(opp); + ret = PTR_ERR(opp); + goto out; } volt = dev_pm_opp_get_voltage(opp); opp_freq = dev_pm_opp_get_freq(opp); @@ -87,7 +129,7 @@ static int set_target(struct cpufreq_policy *policy, unsigned int index) if (ret) { dev_err(cpu_dev, "failed to scale voltage up: %d\n", ret); - return ret; + goto out; } } @@ -96,7 +138,7 @@ static int set_target(struct cpufreq_policy *policy, unsigned int index) dev_err(cpu_dev, "failed to set clock rate: %d\n", ret); if (!IS_ERR(cpu_reg) && volt_old > 0) regulator_set_voltage_tol(cpu_reg, volt_old, tol); - return ret; + goto out; } /* scaling down? scale voltage after frequency */ @@ -106,9 +148,12 @@ static int set_target(struct cpufreq_policy *policy, unsigned int index) dev_err(cpu_dev, "failed to scale voltage down: %d\n", ret); clk_set_rate(cpu_clk, old_freq * 1000); + goto out; } } - + priv->opp_freq = opp_freq; +out: + mutex_unlock(&priv->lock); return ret; } @@ -194,6 +239,7 @@ static int cpufreq_init(struct cpufreq_policy *policy) unsigned long min_uV = ~0, max_uV = 0; unsigned int transition_latency; int ret; + struct srcu_notifier_head *opp_srcu_head; ret = allocate_resources(policy->cpu, &cpu_dev, &cpu_reg, &cpu_clk); if (ret) { @@ -228,6 +274,19 @@ static int cpufreq_init(struct cpufreq_policy *policy) goto out_free_opp; } + mutex_init(&priv->lock); + + opp_srcu_head = dev_pm_opp_get_notifier(cpu_dev); + if (IS_ERR(opp_srcu_head)) { + ret = PTR_ERR(opp_srcu_head); + goto out_free_priv; + } + + priv->opp_nb.notifier_call = opp_notifier; + ret = srcu_notifier_chain_register(opp_srcu_head, &priv->opp_nb); + if (ret) + goto out_free_priv; + of_property_read_u32(np, "voltage-tolerance", &priv->voltage_tolerance); if (of_property_read_u32(np, "clock-latency", &transition_latency)) @@ -276,7 +335,7 @@ static int cpufreq_init(struct cpufreq_policy *policy) ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table); if (ret) { pr_err("failed to init cpufreq table: %d\n", ret); - goto out_free_priv; + goto out_unregister_nb; } priv->cpu_dev = cpu_dev; @@ -303,6 +362,8 @@ static int cpufreq_init(struct cpufreq_policy *policy) out_free_cpufreq_table: dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table); +out_unregister_nb: + srcu_notifier_chain_unregister(opp_srcu_head, &priv->opp_nb); out_free_priv: kfree(priv); out_free_opp: