Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753639Ab3CRK6P (ORCPT ); Mon, 18 Mar 2013 06:58:15 -0400 Received: from mail-ie0-f181.google.com ([209.85.223.181]:50798 "EHLO mail-ie0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753599Ab3CRK6L (ORCPT ); Mon, 18 Mar 2013 06:58:11 -0400 MIME-Version: 1.0 In-Reply-To: References: <1363082299-10561-1-git-send-email-amit.daniel@samsung.com> <1363082299-10561-2-git-send-email-amit.daniel@samsung.com> Date: Mon, 18 Mar 2013 16:28:10 +0530 Message-ID: Subject: Re: [PATCH V4 1/4] cpufreq: exynos: Adding cpufreq driver for exynos5440 From: amit kachhap To: Viresh Kumar Cc: linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, "Rafael J. Wysocki" , linux-samsung-soc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Kukjin Kim , Thomas Abraham , cpufreq@vger.kernel.org, Inderpal Singh , Sylwester Nawrocki , Russell King - ARM Linux Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 9664 Lines: 270 Hi Viresh, On Tue, Mar 12, 2013 at 4:19 PM, Viresh Kumar wrote: > This is what Russell told me a long time back: > "Don't use Adding, Fixing, etc words as this work is not something, which is > already done." > > So your subject should have been: "cpufreq: exynos: Add cpufreq driver > for exynos5440" ok right. > > Fix it if you need another version, which i believe you do :) yes no escape now :) > > On Tue, Mar 12, 2013 at 5:58 PM, Amit Daniel Kachhap > wrote: >> This patch adds dvfs support for exynos5440 SOC. This soc has 4 cores and >> they scale at same frequency. The nature of exynos5440 clock controller is >> different from previous exynos controllers so not using the common exynos >> cpufreq framework. The major difference being interrupt notfication for > > s/notfication/notification ok > >> frequency change. Also, OPP library is used for device tree parsing to get >> different parameters like frequency, voltage etc. Since the opp library sorts >> the frequency table in ascending order so they are again re-arranged in >> descending order. This will have one-to-one mapping with the clock controller >> state management logic. >> >> Signed-off-by: Amit Daniel Kachhap >> --- >> .../bindings/cpufreq/cpufreq-exynos5440.txt | 29 ++ >> drivers/cpufreq/Kconfig.arm | 9 + >> drivers/cpufreq/Makefile | 1 + >> drivers/cpufreq/exynos5440-cpufreq.c | 466 ++++++++++++++++++++ >> 4 files changed, 505 insertions(+), 0 deletions(-) >> create mode 100644 Documentation/devicetree/bindings/cpufreq/cpufreq-exynos5440.txt >> create mode 100644 drivers/cpufreq/exynos5440-cpufreq.c >> >> diff --git a/Documentation/devicetree/bindings/cpufreq/cpufreq-exynos5440.txt b/Documentation/devicetree/bindings/cpufreq/cpufreq-exynos5440.txt >> new file mode 100644 >> index 0000000..a0dbe0b >> --- /dev/null >> +++ b/Documentation/devicetree/bindings/cpufreq/cpufreq-exynos5440.txt >> @@ -0,0 +1,29 @@ >> + >> +Exynos5440 cpufreq driver >> +------------------- >> + >> +Exynos5440 SoC cpufreq driver for CPU frequency scaling. >> + >> +Required properties: >> +- interrupts: Interrupt to know the completion of cpu frequency change. >> +- operating-points: Table of frequencies and voltage CPU could be transitioned into, >> + in the decreasing order. Frequency should be in KHZ units and voltage > > s/KHZ/KHz ok > >> + should be in microvolts. > > probably s/microvolts/micro-volts ?? > >> + >> +Optional properties: >> +- clock-latency: Clock monitor latency in microsecond. >> + >> +All the required listed above must be defined under node cpufreq. >> + >> +Example: >> +-------- >> + cpufreq@160000 { >> + compatible = "samsung,exynos5440-cpufreq"; >> + reg = <0x160000 0x1000>; >> + interrupts = <0 57 0>; >> + operating-points = < >> + 1000000 975000 >> + 800000 925000>; >> + clock-latency = <100000>; >> + }; >> + > >> diff --git a/drivers/cpufreq/exynos5440-cpufreq.c b/drivers/cpufreq/exynos5440-cpufreq.c >> +static void exynos_enable_dvfs(void) >> +{ > >> + /* Set initial performance index */ >> + for (i = 0; freq_table[i].frequency != CPUFREQ_TABLE_END; i++) >> + if (freq_table[i].frequency == dvfs_info->cur_frequency) >> + break; >> + >> + if (freq_table[i].frequency == CPUFREQ_TABLE_END) { >> + dev_crit(dvfs_info->dev, "Boot up frequency not supported\n"); >> + /* Assign the highest frequency */ >> + i = 0; >> + dvfs_info->cur_frequency = freq_table[i].frequency; > > What about: > > dvfs_info->cur_frequency = freq_table[0].frequency; > > as i don't see i being used again? No It is used below for frequency setting. > >> + } > >> +} > >> +static int exynos_target(struct cpufreq_policy *policy, >> + unsigned int target_freq, >> + unsigned int relation) >> +{ > >> + if (cpufreq_frequency_table_target(policy, freq_table, >> + target_freq, relation, &index)) { >> + ret = -EINVAL; > > Use the error value returned by called functions, probably i gave this > comment last time too? yes my mistake. > >> + goto out; >> + } > >> +} > >> +static void exynos_sort_descend_freq_table(void) >> +{ >> + struct cpufreq_frequency_table *freq_tbl = dvfs_info->freq_table; >> + int i = 0, index; >> + unsigned int tmp_freq; >> + >> + /* >> + * Freq table is already in ascending order as it is created from >> + * OPP library, so just swap the elements to make it descending. > > why?? I explained this requirement in the patch commit. Will explain it here again. > >> + */ >> + for (i = 0; i < dvfs_info->freq_count / 2; i++) { >> + index = dvfs_info->freq_count - i - 1; >> + tmp_freq = freq_tbl[i].frequency; >> + freq_tbl[i].frequency = freq_tbl[index].frequency; >> + freq_tbl[index].frequency = tmp_freq; >> + } >> +} >> + > >> +static int exynos_cpufreq_probe(struct platform_device *pdev) >> +{ >> + int ret = -EINVAL; >> + struct device_node *np; >> + struct resource res; >> + >> + np = of_find_compatible_node(NULL, NULL, "samsung,exynos5440-cpufreq"); >> + if (!np) >> + return -ENODEV; >> + >> + dvfs_info = devm_kzalloc(&pdev->dev, sizeof(*dvfs_info), GFP_KERNEL); >> + if (!dvfs_info) { >> + ret = -ENOMEM; >> + goto err_put_node; >> + } >> + >> + dvfs_info->dev = &pdev->dev; >> + dvfs_info->dev->of_node = np; >> + >> + ret = of_address_to_resource(np, 0, &res); >> + if (ret) >> + goto err_put_node; >> + >> + dvfs_info->base = devm_ioremap_resource(dvfs_info->dev, &res); >> + if (IS_ERR(dvfs_info->base)) { >> + ret = PTR_ERR(dvfs_info->base); >> + goto err_put_node; >> + } >> + >> + dvfs_info->irq = irq_of_parse_and_map(np, 0); >> + if (dvfs_info->irq == 0) { > > maybe, if (!dvfs_info->irq) { ok Thanks, Amit Daniel > > >> + dev_err(dvfs_info->dev, "No cpufreq irq found\n"); >> + ret = -ENODEV; >> + goto err_put_node; >> + } >> + >> + ret = of_init_opp_table(dvfs_info->dev); >> + if (ret) { >> + dev_err(dvfs_info->dev, "failed to init OPP table: %d\n", ret); >> + goto err_put_node; >> + } >> + >> + ret = opp_init_cpufreq_table(dvfs_info->dev, &dvfs_info->freq_table); >> + if (ret) { >> + dev_err(dvfs_info->dev, >> + "failed to init cpufreq table: %d\n", ret); >> + goto err_put_node; >> + } >> + dvfs_info->freq_count = opp_get_opp_count(dvfs_info->dev); >> + exynos_sort_descend_freq_table(); >> + >> + if (of_property_read_u32(np, "clock-latency", &dvfs_info->latency)) >> + dvfs_info->latency = DEF_TRANS_LATENCY; >> + >> + dvfs_info->cpu_clk = devm_clk_get(dvfs_info->dev, "armclk"); >> + if (IS_ERR(dvfs_info->cpu_clk)) { >> + dev_err(dvfs_info->dev, "Failed to get cpu clock\n"); >> + ret = PTR_ERR(dvfs_info->cpu_clk); >> + goto err_free_table; >> + } >> + >> + dvfs_info->cur_frequency = clk_get_rate(dvfs_info->cpu_clk); >> + if (!dvfs_info->cur_frequency) { >> + dev_err(dvfs_info->dev, "Failed to get clock rate\n"); >> + ret = -EINVAL; >> + goto err_free_table; >> + } >> + dvfs_info->cur_frequency /= 1000; >> + >> + INIT_WORK(&dvfs_info->irq_work, exynos_cpufreq_work); >> + ret = devm_request_irq(dvfs_info->dev, dvfs_info->irq, >> + exynos_cpufreq_irq, IRQF_TRIGGER_NONE, >> + CPUFREQ_NAME, dvfs_info); >> + if (ret) { >> + dev_err(dvfs_info->dev, "Failed to register IRQ\n"); >> + goto err_free_table; >> + } >> + >> + ret = init_div_table(); >> + if (ret) { >> + dev_err(dvfs_info->dev, "Failed to initialise div table\n"); >> + goto err_free_table; >> + } >> + >> + exynos_enable_dvfs(); >> + ret = cpufreq_register_driver(&exynos_driver); >> + if (ret) { >> + dev_err(dvfs_info->dev, >> + "%s: failed to register cpufreq driver\n", __func__); >> + goto err_free_table; >> + } >> + >> + of_node_put(np); >> + dvfs_info->dvfs_enabled = true; >> + return 0; >> + >> +err_free_table: >> + opp_free_cpufreq_table(dvfs_info->dev, &dvfs_info->freq_table); >> +err_put_node: >> + of_node_put(np); >> + dev_err(dvfs_info->dev, "%s: failed initialization\n", __func__); >> + return ret; >> +} > -- > To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/