Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933101AbcKPNvH (ORCPT ); Wed, 16 Nov 2016 08:51:07 -0500 Received: from mx1.redhat.com ([209.132.183.28]:56406 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932982AbcKPNu7 (ORCPT ); Wed, 16 Nov 2016 08:50:59 -0500 From: fu.wei@linaro.org To: rjw@rjwysocki.net, lenb@kernel.org, daniel.lezcano@linaro.org, tglx@linutronix.de, marc.zyngier@arm.com, mark.rutland@arm.com, lorenzo.pieralisi@arm.com, sudeep.holla@arm.com, hanjun.guo@linaro.org Cc: linux-arm-kernel@lists.infradead.org, linaro-acpi@lists.linaro.org, linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, rruigrok@codeaurora.org, harba@codeaurora.org, cov@codeaurora.org, timur@codeaurora.org, graeme.gregory@linaro.org, al.stone@linaro.org, jcm@redhat.com, wei@redhat.com, arnd@arndb.de, catalin.marinas@arm.com, will.deacon@arm.com, Suravee.Suthikulpanit@amd.com, leo.duran@amd.com, wim@iguana.be, linux@roeck-us.net, linux-watchdog@vger.kernel.org, tn@semihalf.com, christoffer.dall@linaro.org, julien.grall@arm.com, Fu Wei Subject: [PATCH v16 07/15] clocksource/drivers/arm_arch_timer: Refactor arch_timer_detect_rate to keep dt code in *_of_init Date: Wed, 16 Nov 2016 21:49:00 +0800 Message-Id: <1479304148-2965-8-git-send-email-fu.wei@linaro.org> In-Reply-To: <1479304148-2965-1-git-send-email-fu.wei@linaro.org> References: <1479304148-2965-1-git-send-email-fu.wei@linaro.org> X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Wed, 16 Nov 2016 13:50:53 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3332 Lines: 102 From: Fu Wei The patch refactor original arch_timer_detect_rate function: (1) Separate out device-tree code, keep them in device-tree init function: arch_timer_of_init, arch_timer_mem_init; (2) Improve original mechanism, if getting from memory-mapped timer fail, try arch_timer_get_cntfrq() again. Signed-off-by: Fu Wei --- drivers/clocksource/arm_arch_timer.c | 45 +++++++++++++++++++++++------------- 1 file changed, 29 insertions(+), 16 deletions(-) diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c index af22953..fe4e812 100644 --- a/drivers/clocksource/arm_arch_timer.c +++ b/drivers/clocksource/arm_arch_timer.c @@ -487,27 +487,31 @@ static int arch_timer_starting_cpu(unsigned int cpu) return 0; } -static void -arch_timer_detect_rate(void __iomem *cntbase, struct device_node *np) +static void arch_timer_detect_rate(void __iomem *cntbase) { /* Who has more than one independent system counter? */ if (arch_timer_rate) return; - /* - * Try to determine the frequency from the device tree or CNTFRQ, - * if ACPI is enabled, get the frequency from CNTFRQ ONLY. + * If we got memory-mapped timer(cntbase != NULL), + * try to determine the frequency from CNTFRQ in memory-mapped timer. */ - if (!acpi_disabled || - of_property_read_u32(np, "clock-frequency", &arch_timer_rate)) { - if (cntbase) - arch_timer_rate = readl_relaxed(cntbase + CNTFRQ); - else - arch_timer_rate = arch_timer_get_cntfrq(); - } + if (cntbase) + arch_timer_rate = readl_relaxed(cntbase + CNTFRQ); + /* + * Because in a system that implements both Secure and + * Non-secure states, CNTFRQ is only accessible in Secure state. + * So the operation above may fail, even if (cntbase != NULL), + * especially on ARM64. + * In this case, we can try cntfrq_el0(system coprocessor register). + */ + if (!arch_timer_rate) + arch_timer_rate = arch_timer_get_cntfrq(); + else + return; /* Check the timer frequency. */ - if (arch_timer_rate == 0) + if (!arch_timer_rate) pr_warn("frequency not available\n"); } @@ -883,7 +887,9 @@ static int __init arch_timer_of_init(struct device_node *np) for (i = ARCH_TIMER_PHYS_SECURE_PPI; i < ARCH_TIMER_MAX_TIMER_PPI; i++) arch_timer_ppi[i] = irq_of_parse_and_map(np, i); - arch_timer_detect_rate(NULL, np); + if (!arch_timer_rate && + of_property_read_u32(np, "clock-frequency", &arch_timer_rate)) + arch_timer_detect_rate(NULL); arch_timer_c3stop = !of_property_read_bool(np, "always-on"); @@ -983,7 +989,14 @@ static int __init arch_timer_mem_init(struct device_node *np) goto out; } - arch_timer_detect_rate(base, np); + /* + * Try to determine the frequency from the device tree, + * if fail, get the frequency from CNTFRQ. + */ + if (!arch_timer_rate && + of_property_read_u32(np, "clock-frequency", &arch_timer_rate)) + arch_timer_detect_rate(base); + ret = arch_timer_mem_register(base, irq); if (ret) goto out; @@ -1046,7 +1059,7 @@ static int __init arch_timer_acpi_init(struct acpi_table_header *table) gtdt->non_secure_el2_flags); /* Get the frequency from CNTFRQ */ - arch_timer_detect_rate(NULL, NULL); + arch_timer_detect_rate(NULL); ret = arch_timer_uses_ppi_init(); if (ret) -- 2.7.4