From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mikko Perttunen Subject: Re: [RFC PATCH 4/4] cpufreq: tegra: Register a minimum EMC frequency based on the CPU clock Date: Mon, 16 Jun 2014 17:08:43 +0300 Message-ID: <539EFA6B.20501@kapsi.fi> References: <1402925713-25426-1-git-send-email-tomeu.vizoso@collabora.com> <1402925713-25426-5-git-send-email-tomeu.vizoso@collabora.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1402925713-25426-5-git-send-email-tomeu.vizoso@collabora.com> Sender: linux-kernel-owner@vger.kernel.org To: Tomeu Vizoso , Stephen Warren , Thierry Reding , "Rafael J. Wysocki" , David Airlie , Mike Turquette , myungjoo.ham@samsung.com, kyungmin.park@samsung.com, devicetree@vger.kernel.org, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-pm@vger.kernel.org, dri-devel@lists.freedesktop.org List-Id: dri-devel@lists.freedesktop.org The tegra-cpufreq driver is only for Tegra20, an upcoming driver for Tegra124 will be separate, so this is not needed. Thanks, - Mikko On 06/16/2014 04:35 PM, Tomeu Vizoso wrote: > Instead of setting a direct correlation to the CPU frequency. This allows > for other devices to influence the final effective EMC frequency. > > In the future, this should be done instead by an ACTMON driver, > which would also take load stats into account when calculating the > floor EMC frequency. > > Signed-off-by: Tomeu Vizoso > --- > drivers/cpufreq/tegra-cpufreq.c | 20 +++++--------------- > 1 file changed, 5 insertions(+), 15 deletions(-) > > diff --git a/drivers/cpufreq/tegra-cpufreq.c b/drivers/cpufreq/tegra-cpufreq.c > index 8084c7f..64935f8 100644 > --- a/drivers/cpufreq/tegra-cpufreq.c > +++ b/drivers/cpufreq/tegra-cpufreq.c > @@ -26,6 +26,7 @@ > #include > #include > #include > +#include > > static struct cpufreq_frequency_table freq_table[] = { > { .frequency = 216000 }, > @@ -44,7 +45,6 @@ static struct cpufreq_frequency_table freq_table[] = { > static struct clk *cpu_clk; > static struct clk *pll_x_clk; > static struct clk *pll_p_clk; > -static struct clk *emc_clk; > static bool pll_x_prepared; > > static unsigned int tegra_get_intermediate(struct cpufreq_policy *policy, > @@ -96,15 +96,15 @@ static int tegra_target(struct cpufreq_policy *policy, unsigned int index) > int ret = 0; > > /* > - * Vote on memory bus frequency based on cpu frequency > + * Set minimum memory bus frequency based on cpu frequency > * This sets the minimum frequency, display or avp may request higher > */ > if (rate >= 816000) > - clk_set_rate(emc_clk, 600000000); /* cpu 816 MHz, emc max */ > + tegra124_emc_set_floor(600000000); /* cpu 816 MHz, emc max */ > else if (rate >= 456000) > - clk_set_rate(emc_clk, 300000000); /* cpu 456 MHz, emc 150Mhz */ > + tegra124_emc_set_floor(300000000); /* cpu 456 MHz, emc 150Mhz */ > else > - clk_set_rate(emc_clk, 100000000); /* emc 50Mhz */ > + tegra124_emc_set_floor(100000000); /* emc 50Mhz */ > > /* > * target freq == pll_p, don't need to take extra reference to pll_x_clk > @@ -141,14 +141,12 @@ static int tegra_cpu_init(struct cpufreq_policy *policy) > if (policy->cpu >= NUM_CPUS) > return -EINVAL; > > - clk_prepare_enable(emc_clk); > clk_prepare_enable(cpu_clk); > > /* FIXME: what's the actual transition time? */ > ret = cpufreq_generic_init(policy, freq_table, 300 * 1000); > if (ret) { > clk_disable_unprepare(cpu_clk); > - clk_disable_unprepare(emc_clk); > return ret; > } > > @@ -160,7 +158,6 @@ static int tegra_cpu_init(struct cpufreq_policy *policy) > static int tegra_cpu_exit(struct cpufreq_policy *policy) > { > clk_disable_unprepare(cpu_clk); > - clk_disable_unprepare(emc_clk); > return 0; > } > > @@ -194,19 +191,12 @@ static int __init tegra_cpufreq_init(void) > if (IS_ERR(pll_p_clk)) > return PTR_ERR(pll_p_clk); > > - emc_clk = clk_get_sys("cpu", "emc"); > - if (IS_ERR(emc_clk)) { > - clk_put(cpu_clk); > - return PTR_ERR(emc_clk); > - } > - > return cpufreq_register_driver(&tegra_cpufreq_driver); > } > > static void __exit tegra_cpufreq_exit(void) > { > cpufreq_unregister_driver(&tegra_cpufreq_driver); > - clk_put(emc_clk); > clk_put(cpu_clk); > } > >