From patchwork Fri Jan 25 19:46:45 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Langsdorf X-Patchwork-Id: 2047161 Return-Path: X-Original-To: patchwork-linux-pm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork1.kernel.org (Postfix) with ESMTP id CB2883FDD1 for ; Fri, 25 Jan 2013 19:47:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751420Ab3AYTrY (ORCPT ); Fri, 25 Jan 2013 14:47:24 -0500 Received: from smtp187.dfw.emailsrvr.com ([67.192.241.187]:55099 "EHLO smtp187.dfw.emailsrvr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751805Ab3AYTqm (ORCPT ); Fri, 25 Jan 2013 14:46:42 -0500 Received: from localhost (localhost.localdomain [127.0.0.1]) by smtp18.relay.dfw1a.emailsrvr.com (SMTP Server) with ESMTP id A1FD4268366; Fri, 25 Jan 2013 14:46:41 -0500 (EST) X-Virus-Scanned: OK Received: by smtp18.relay.dfw1a.emailsrvr.com (Authenticated sender: mark.langsdorf-AT-calxeda.com) with ESMTPSA id 69A9B268265; Fri, 25 Jan 2013 14:46:41 -0500 (EST) From: Mark Langsdorf To: linux-kernel@vger.kernel.org, cpufreq@vger.kernel.org, linux-pm@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: Mark Langsdorf Subject: [PATCH 4/4] cpufreq, highbank: add support for highbank cpufreq Date: Fri, 25 Jan 2013 13:46:45 -0600 Message-Id: <1359143205-20279-5-git-send-email-mark.langsdorf@calxeda.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1359143205-20279-1-git-send-email-mark.langsdorf@calxeda.com> References: <1351631056-25938-1-git-send-email-mark.langsdorf@calxeda.com> <1359143205-20279-1-git-send-email-mark.langsdorf@calxeda.com> Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org Highbank processors depend on the external ECME to perform voltage management based on a requested frequency. Communication between the A9 cores and the ECME happens over the pl320 IPC channel. Signed-off-by: Mark Langsdorf Reviewed-by: Shawn Guo Reviewed-by: Mike Turquette --- Changes from v10 Now finds a cpu node by searching under /cpus and looking for something with an operating-points descriptor. This applies to both highbank-cpufreq and cpufreq-cpu0. Changes from v9 Added Mike Turquette's reviewed by. Used to be the 6th patch in the series. Changes from v8 Added Shawn Guo's reviewed by. Removed some magic numbers. Changed failure returns in clk_notify from NOTIFY_STOP to NOTIFY_BAD. Changes from v7 Removed old attribution to cpufreq-cpu0. Added some description in the documentation. Made cpu_dev, cpu_clk into local variables. Removed __devinit. Removed some unneeded includes. Added a brace to clarify some nested if logic. Changes from v6 Removed devicetree bindings documentation. Restructured driver to use clk notifications. Core driver logic is now cpufreq-clk0. Changes from v5 Changed ipc_transmit() to pl320_ipc_transmit(). Changes from v4 Removed erroneous changes to arch/arm/Kconfig. Removed unnecessary changes to drivers/cpufreq/Kconfig.arm Alphabetized additions to arch/arm/mach-highbank/Kconfig Changed ipc call and header to match new ipc location in drivers/mailbox. Changes from v3 None. Changes from v2 Changed transition latency binding in code to match documentation. Changes from v1 Added highbank specific Kconfig changes. arch/arm/boot/dts/highbank.dts | 10 ++++ arch/arm/mach-highbank/Kconfig | 2 + drivers/cpufreq/Kconfig.arm | 15 +++++ drivers/cpufreq/Makefile | 3 +- drivers/cpufreq/cpufreq-cpu0.c | 6 +- drivers/cpufreq/highbank-cpufreq.c | 112 +++++++++++++++++++++++++++++++++++++ 6 files changed, 146 insertions(+), 2 deletions(-) create mode 100644 drivers/cpufreq/highbank-cpufreq.c diff --git a/arch/arm/boot/dts/highbank.dts b/arch/arm/boot/dts/highbank.dts index 5927a8d..6aad34a 100644 --- a/arch/arm/boot/dts/highbank.dts +++ b/arch/arm/boot/dts/highbank.dts @@ -37,6 +37,16 @@ next-level-cache = <&L2>; clocks = <&a9pll>; clock-names = "cpu"; + operating-points = < + /* kHz ignored */ + 1300000 1000000 + 1200000 1000000 + 1100000 1000000 + 800000 1000000 + 400000 1000000 + 200000 1000000 + >; + clock-latency = <100000>; }; cpu@901 { diff --git a/arch/arm/mach-highbank/Kconfig b/arch/arm/mach-highbank/Kconfig index 2388085..44b12f9 100644 --- a/arch/arm/mach-highbank/Kconfig +++ b/arch/arm/mach-highbank/Kconfig @@ -1,5 +1,7 @@ config ARCH_HIGHBANK bool "Calxeda ECX-1000/2000 (Highbank/Midway)" if ARCH_MULTI_V7 + select ARCH_HAS_CPUFREQ + select ARCH_HAS_OPP select ARCH_WANT_OPTIONAL_GPIOLIB select ARM_AMBA select ARM_GIC diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm index a0b3661..ffe55b8 100644 --- a/drivers/cpufreq/Kconfig.arm +++ b/drivers/cpufreq/Kconfig.arm @@ -83,3 +83,18 @@ config ARM_SPEAR_CPUFREQ default y help This adds the CPUFreq driver support for SPEAr SOCs. + +config ARM_HIGHBANK_CPUFREQ + tristate "Calxeda Highbank-based" + depends on ARCH_HIGHBANK + select CPU_FREQ_TABLE + select GENERIC_CPUFREQ_CPU0 + select PM_OPP + select REGULATOR + + default m + help + This adds the CPUFreq driver for Calxeda Highbank SoC + based boards. + + If in doubt, say N. diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile index fadc4d4..31e6f19 100644 --- a/drivers/cpufreq/Makefile +++ b/drivers/cpufreq/Makefile @@ -50,8 +50,9 @@ obj-$(CONFIG_ARM_EXYNOS_CPUFREQ) += exynos-cpufreq.o obj-$(CONFIG_ARM_EXYNOS4210_CPUFREQ) += exynos4210-cpufreq.o obj-$(CONFIG_ARM_EXYNOS4X12_CPUFREQ) += exynos4x12-cpufreq.o obj-$(CONFIG_ARM_EXYNOS5250_CPUFREQ) += exynos5250-cpufreq.o -obj-$(CONFIG_ARM_OMAP2PLUS_CPUFREQ) += omap-cpufreq.o +obj-$(CONFIG_ARM_OMAP2PLUS_CPUFREQ) += omap-cpufreq.o obj-$(CONFIG_ARM_SPEAR_CPUFREQ) += spear-cpufreq.o +obj-$(CONFIG_ARM_HIGHBANK_CPUFREQ) += highbank-cpufreq.o ################################################################################## # PowerPC platform drivers diff --git a/drivers/cpufreq/cpufreq-cpu0.c b/drivers/cpufreq/cpufreq-cpu0.c index 52bf36d..90e9d73 100644 --- a/drivers/cpufreq/cpufreq-cpu0.c +++ b/drivers/cpufreq/cpufreq-cpu0.c @@ -179,7 +179,11 @@ static int cpu0_cpufreq_driver_init(void) struct device_node *np; int ret; - np = of_find_node_by_path("/cpus/cpu@0"); + for_each_child_of_node(of_find_node_by_path("/cpus"), np) { + if (of_get_property(np, "operating-points", NULL)) + break; + } + if (!np) { pr_err("failed to find cpu0 node\n"); return -ENOENT; diff --git a/drivers/cpufreq/highbank-cpufreq.c b/drivers/cpufreq/highbank-cpufreq.c new file mode 100644 index 0000000..a5bad89 --- /dev/null +++ b/drivers/cpufreq/highbank-cpufreq.c @@ -0,0 +1,112 @@ +/* + * Copyright (C) 2012 Calxeda, Inc. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This driver provides the clk notifier callbacks that are used when + * the cpufreq-cpu0 driver changes to frequency to alert the highbank + * EnergyCore Management Engine (ECME) about the need to change + * voltage. The ECME interfaces with the actual voltage regulators. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include +#include +#include +#include + +#define HB_CPUFREQ_CHANGE_NOTE 0x80000001 +#define HB_CPUFREQ_IPC_LEN 7 +#define HB_CPUFREQ_VOLT_RETRIES 15 + +static int hb_voltage_change(unsigned int freq) +{ + int i; + u32 msg[HB_CPUFREQ_IPC_LEN]; + + msg[0] = HB_CPUFREQ_CHANGE_NOTE; + msg[1] = freq / 1000000; + for (i = 2; i < HB_CPUFREQ_IPC_LEN; i++) + msg[i] = 0; + + return pl320_ipc_transmit(msg); +} + +static int hb_cpufreq_clk_notify(struct notifier_block *nb, + unsigned long action, void *hclk) +{ + struct clk_notifier_data *clk_data = hclk; + int i = 0; + + if (action == PRE_RATE_CHANGE) { + if (clk_data->new_rate > clk_data->old_rate) + while (hb_voltage_change(clk_data->new_rate)) + if (i++ > HB_CPUFREQ_VOLT_RETRIES) + return NOTIFY_BAD; + } else if (action == POST_RATE_CHANGE) { + if (clk_data->new_rate < clk_data->old_rate) + while (hb_voltage_change(clk_data->new_rate)) + if (i++ > HB_CPUFREQ_VOLT_RETRIES) + return NOTIFY_BAD; + } + + return NOTIFY_DONE; +} + +static struct notifier_block hb_cpufreq_clk_nb = { + .notifier_call = hb_cpufreq_clk_notify, +}; + +static int hb_cpufreq_driver_init(void) +{ + struct device *cpu_dev; + struct clk *cpu_clk; + struct device_node *np; + int ret; + + for_each_child_of_node(of_find_node_by_path("/cpus"), np) + if (of_get_property(np, "operating-points", NULL)) + break; + + if (!np) { + pr_err("failed to find highbank cpufreq node\n"); + return -ENOENT; + } + + cpu_dev = get_cpu_device(0); + if (!cpu_dev) { + pr_err("failed to get highbank cpufreq device\n"); + ret = -ENODEV; + goto out_put_node; + } + + cpu_dev->of_node = np; + + cpu_clk = clk_get(cpu_dev, NULL); + if (IS_ERR(cpu_clk)) { + ret = PTR_ERR(cpu_clk); + pr_err("failed to get cpu0 clock: %d\n", ret); + goto out_put_node; + } + + ret = clk_notifier_register(cpu_clk, &hb_cpufreq_clk_nb); + if (ret) { + pr_err("failed to register clk notifier: %d\n", ret); + goto out_put_node; + } + +out_put_node: + of_node_put(np); + return ret; +} +module_init(hb_cpufreq_driver_init); + +MODULE_AUTHOR("Mark Langsdorf "); +MODULE_DESCRIPTION("Calxeda Highbank cpufreq driver"); +MODULE_LICENSE("GPL");