From patchwork Mon Feb 10 10:10:56 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ivan Khoronzhuk X-Patchwork-Id: 3617531 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 301079F382 for ; Mon, 10 Feb 2014 10:15:02 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 24CA620155 for ; Mon, 10 Feb 2014 10:15:01 +0000 (UTC) Received: from casper.infradead.org (casper.infradead.org [85.118.1.10]) (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 D1F5C20179 for ; Mon, 10 Feb 2014 10:14:59 +0000 (UTC) Received: from merlin.infradead.org ([2001:4978:20e::2]) by casper.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1WCnrK-0006Ff-7c; Mon, 10 Feb 2014 10:13:03 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1WCnqk-000629-62; Mon, 10 Feb 2014 10:12:26 +0000 Received: from devils.ext.ti.com ([198.47.26.153]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1WCnqU-0005xC-GU for linux-arm-kernel@lists.infradead.org; Mon, 10 Feb 2014 10:12:13 +0000 Received: from dlelxv90.itg.ti.com ([172.17.2.17]) by devils.ext.ti.com (8.13.7/8.13.7) with ESMTP id s1AABAU1000978; Mon, 10 Feb 2014 04:11:10 -0600 Received: from DFLE73.ent.ti.com (dfle73.ent.ti.com [128.247.5.110]) by dlelxv90.itg.ti.com (8.14.3/8.13.8) with ESMTP id s1AAB96g021937; Mon, 10 Feb 2014 04:11:09 -0600 Received: from dflp32.itg.ti.com (10.64.6.15) by DFLE73.ent.ti.com (128.247.5.110) with Microsoft SMTP Server id 14.2.342.3; Mon, 10 Feb 2014 04:11:09 -0600 Received: from khorivan.itg.ti.com (incasgf5a_e1_2.itg.ti.com [10.167.216.36]) by dflp32.itg.ti.com (8.14.3/8.13.8) with ESMTP id s1AAB0bB028214; Mon, 10 Feb 2014 04:11:06 -0600 From: Ivan Khoronzhuk To: , , , Subject: [PATCH v6 1/3] clocksource: timer-keystone: introduce clocksource driver for Keystone Date: Mon, 10 Feb 2014 12:10:56 +0200 Message-ID: <1392027058-11680-2-git-send-email-ivan.khoronzhuk@ti.com> X-Mailer: git-send-email 1.8.3.2 In-Reply-To: <1392027058-11680-1-git-send-email-ivan.khoronzhuk@ti.com> References: <1392027058-11680-1-git-send-email-ivan.khoronzhuk@ti.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20140210_051210_752142_12D9F090 X-CRM114-Status: GOOD ( 17.46 ) X-Spam-Score: -4.5 (----) Cc: mark.rutland@arm.com, devicetree@vger.kernel.org, grygorii.strashko@ti.com, pawel.moll@arm.com, ijc+devicetree@hellion.org.uk, joshc@codeaurora.org, daniel.lezcano@linaro.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, robh+dt@kernel.org, Ivan Khoronzhuk , tglx@linutronix.de, linux-arm-kernel@lists.infradead.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-1.8 required=5.0 tests=BAYES_00,KHOP_BIG_TO_CC, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=no version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Add broadcast clock-event device for the Keystone arch. The timer can be configured as a general-purpose 64-bit timer, dual general-purpose 32-bit timers. When configured as dual 32-bit timers, each half can operate in conjunction (chain mode) or independently (unchained mode) of each other. Reviewed-by: Stephen Boyd Acked-by: Santosh shilimkar Signed-off-by: Ivan Khoronzhuk --- drivers/clocksource/Makefile | 1 + drivers/clocksource/timer-keystone.c | 244 +++++++++++++++++++++++++++++++++++ 2 files changed, 245 insertions(+) create mode 100644 drivers/clocksource/timer-keystone.c diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile index c7ca50a..4abe5aa 100644 --- a/drivers/clocksource/Makefile +++ b/drivers/clocksource/Makefile @@ -37,3 +37,4 @@ obj-$(CONFIG_ARM_ARCH_TIMER) += arm_arch_timer.o obj-$(CONFIG_ARM_GLOBAL_TIMER) += arm_global_timer.o obj-$(CONFIG_CLKSRC_METAG_GENERIC) += metag_generic.o obj-$(CONFIG_ARCH_HAS_TICK_BROADCAST) += dummy_timer.o +obj-$(CONFIG_ARCH_KEYSTONE) += timer-keystone.o diff --git a/drivers/clocksource/timer-keystone.c b/drivers/clocksource/timer-keystone.c new file mode 100644 index 0000000..86b08cd --- /dev/null +++ b/drivers/clocksource/timer-keystone.c @@ -0,0 +1,244 @@ +/* + * Keystone broadcast clock-event + * + * Copyright 2013 Texas Instruments, Inc. + * + * Author: Ivan Khoronzhuk + * + * 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. + * + */ + +#include +#include +#include +#include +#include +#include + +#define TIMER_NAME "timer-keystone" + +/* Timer register offsets */ +#define TIM12 0x10 +#define TIM34 0x14 +#define PRD12 0x18 +#define PRD34 0x1c +#define TCR 0x20 +#define TGCR 0x24 +#define INTCTLSTAT 0x44 + +/* Timer register bitfields */ +#define TCR_ENAMODE_MASK 0xC0 +#define TCR_ENAMODE_ONESHOT_MASK 0x40 +#define TCR_ENAMODE_PERIODIC_MASK 0x80 + +#define TGCR_TIM_UNRESET_MASK 0x03 +#define INTCTLSTAT_ENINT_MASK 0x01 + +/** + * struct keystone_timer: holds timer's data + * @base: timer memory base address + * @hz_period: cycles per HZ period + * @event_dev: event device based on timer + */ +static struct keystone_timer { + void __iomem *base; + unsigned long hz_period; + struct clock_event_device event_dev; +} timer; + +static inline u32 keystone_timer_readl(unsigned long rg) +{ + return readl_relaxed(timer.base + rg); +} + +static inline void keystone_timer_writel(u32 val, unsigned long rg) +{ + writel_relaxed(val, timer.base + rg); +} + +/** + * keystone_timer_barrier: write memory barrier + * use explicit barrier to avoid using readl/writel non relaxed function + * variants, because in our case non relaxed variants hide the true places + * where barrier is needed. + */ +static inline void keystone_timer_barrier(void) +{ + __iowmb(); +} + +/** + * keystone_timer_config: configures timer to work in oneshot/periodic modes. + * @ mode: mode to configure + * @ period: cycles number to configure for + */ +static int keystone_timer_config(u64 period, enum clock_event_mode mode) +{ + u32 tcr; + u32 off; + + tcr = keystone_timer_readl(TCR); + off = tcr & ~(TCR_ENAMODE_MASK); + + /* set enable mode */ + switch (mode) { + case CLOCK_EVT_MODE_ONESHOT: + tcr |= TCR_ENAMODE_ONESHOT_MASK; + break; + case CLOCK_EVT_MODE_PERIODIC: + tcr |= TCR_ENAMODE_PERIODIC_MASK; + break; + default: + return -1; + } + + /* disable timer */ + keystone_timer_writel(off, TCR); + /* here we have to be sure the timer has been disabled */ + keystone_timer_barrier(); + + /* reset counter to zero, set new period */ + keystone_timer_writel(0, TIM12); + keystone_timer_writel(0, TIM34); + keystone_timer_writel(period & 0xffffffff, PRD12); + keystone_timer_writel(period >> 32, PRD34); + + /* + * enable timer + * here we have to be sure that CNTLO, CNTHI, PRDLO, PRDHI registers + * have been written. + */ + keystone_timer_barrier(); + keystone_timer_writel(tcr, TCR); + return 0; +} + +static void keystone_timer_disable(void) +{ + u32 tcr; + + tcr = keystone_timer_readl(TCR); + + /* disable timer */ + tcr &= ~(TCR_ENAMODE_MASK); + keystone_timer_writel(tcr, TCR); +} + +static irqreturn_t keystone_timer_interrupt(int irq, void *dev_id) +{ + struct clock_event_device *evt = dev_id; + + evt->event_handler(evt); + return IRQ_HANDLED; +} + +static int keystone_set_next_event(unsigned long cycles, + struct clock_event_device *evt) +{ + return keystone_timer_config(cycles, evt->mode); +} + +static void keystone_set_mode(enum clock_event_mode mode, + struct clock_event_device *evt) +{ + switch (mode) { + case CLOCK_EVT_MODE_PERIODIC: + keystone_timer_config(timer.hz_period, CLOCK_EVT_MODE_PERIODIC); + break; + case CLOCK_EVT_MODE_UNUSED: + case CLOCK_EVT_MODE_SHUTDOWN: + case CLOCK_EVT_MODE_ONESHOT: + keystone_timer_disable(); + break; + default: + break; + } +} + +static void __init keystone_timer_init(struct device_node *np) +{ + struct clock_event_device *event_dev = &timer.event_dev; + unsigned long rate; + struct clk *clk; + int irq, error; + u32 tgcr; + + irq = irq_of_parse_and_map(np, 0); + if (irq == NO_IRQ) { + pr_err("%s: failed to map interrupts\n", __func__); + return; + } + + timer.base = of_iomap(np, 0); + if (!timer.base) { + pr_err("%s: failed to map registers\n", __func__); + return; + } + + clk = of_clk_get(np, 0); + if (IS_ERR(clk)) { + pr_err("%s: failed to get clock\n", __func__); + iounmap(timer.base); + return; + } + + error = clk_prepare_enable(clk); + if (error) { + pr_err("%s: failed to enable clock\n", __func__); + goto err; + } + + rate = clk_get_rate(clk); + + /* disable, use internal clock source */ + keystone_timer_writel(0, TCR); + /* here we have to be sure the timer has been disabled */ + keystone_timer_barrier(); + + /* reset timer as 64-bit, no pre-scaler, plus features are disabled */ + tgcr = 0; + keystone_timer_writel(0, TGCR); + + /* unreset timer */ + tgcr |= TGCR_TIM_UNRESET_MASK; + keystone_timer_writel(tgcr, TGCR); + + /* init counter to zero */ + keystone_timer_writel(0, TIM12); + keystone_timer_writel(0, TIM34); + + timer.hz_period = DIV_ROUND_UP(rate, HZ); + + /* enable timer interrupts */ + keystone_timer_writel(INTCTLSTAT_ENINT_MASK, INTCTLSTAT); + + error = request_irq(irq, keystone_timer_interrupt, IRQF_TIMER, + TIMER_NAME, event_dev); + if (error) { + pr_err("%s: failed to setup irq\n", __func__); + goto err; + } + + /* setup clockevent */ + event_dev->features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT; + event_dev->set_next_event = keystone_set_next_event; + event_dev->set_mode = keystone_set_mode; + event_dev->cpumask = cpu_all_mask; + event_dev->owner = THIS_MODULE; + event_dev->name = TIMER_NAME; + event_dev->irq = irq; + + clockevents_config_and_register(event_dev, rate, 1, ULONG_MAX); + + pr_info("keystone timer clock @%lu Hz\n", rate); + return; +err: + clk_put(clk); + iounmap(timer.base); +} + +CLOCKSOURCE_OF_DECLARE(keystone_timer, "ti,keystone-timer", + keystone_timer_init);