Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752047Ab3F0LX5 (ORCPT ); Thu, 27 Jun 2013 07:23:57 -0400 Received: from mail-lb0-f175.google.com ([209.85.217.175]:54093 "EHLO mail-lb0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751199Ab3F0LX4 (ORCPT ); Thu, 27 Jun 2013 07:23:56 -0400 From: Jonas Jensen To: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org, arm@kernel.org, john.stultz@linaro.org, tglx@linutronix.de, u.kleine-koenig@pengutronix.de, tomasz.figa@gmail.com, linus.walleij@linaro.org, thomas.petazzoni@free-electrons.com, arnd@arndb.de, Jonas Jensen Subject: [PATCH v3] ARM: clocksource: add support for MOXA ART SoCs Date: Thu, 27 Jun 2013 13:23:23 +0200 Message-Id: <1372332203-30228-1-git-send-email-jonas.jensen@gmail.com> X-Mailer: git-send-email 1.8.2.1 In-Reply-To: <1372258383-24524-1-git-send-email-jonas.jensen@gmail.com> References: <1372258383-24524-1-git-send-email-jonas.jensen@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6433 Lines: 222 This patch adds an clocksource driver for the main timer(s) found on MOXA ART SoCs. Signed-off-by: Jonas Jensen --- Notes: Applies to next-20130619 Changes since v2: 1. remove unused defines: MAX_TIMER, USED_TIMER, APB_CLK 2. split register defines so each timer has a base 3. use standard multiline comments 4. replace whitespaces with tabs 5. rename "timer_base" "base" 6. rename "clock_frequency" "clock_count_per_tick" 7. disable TIMER1 in CLOCK_EVT_MODE_ONESHOT 8. remove pr_debug:s 9. in CLOCK_EVT_MODE_PERIODIC, switch order, write clock_count_per_tick to TIMER1 LOAD and enable it 10. enable TIMER1 in moxart_clkevt_next_event 11. remove IRQF_DISABLED, IRQF_IRQPOLL from irqaction flags 12. set clock_frequency exclusively from system clock 13. bail if of_clk_get fails 14. assign clock_count_per_tick to DIV_ROUND_CLOSEST(pclk, HZ) 15. align continuation lines with matching opening brace drivers/clocksource/Makefile | 1 + drivers/clocksource/moxart_timer.c | 166 +++++++++++++++++++++++++++++++++++++ 2 files changed, 167 insertions(+) create mode 100644 drivers/clocksource/moxart_timer.c diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile index 8d979c7..c93e1a8 100644 --- a/drivers/clocksource/Makefile +++ b/drivers/clocksource/Makefile @@ -29,3 +29,4 @@ obj-$(CONFIG_CLKSRC_SAMSUNG_PWM) += samsung_pwm_timer.o obj-$(CONFIG_ARM_ARCH_TIMER) += arm_arch_timer.o obj-$(CONFIG_CLKSRC_METAG_GENERIC) += metag_generic.o +obj-$(CONFIG_ARCH_MOXART) += moxart_timer.o diff --git a/drivers/clocksource/moxart_timer.c b/drivers/clocksource/moxart_timer.c new file mode 100644 index 0000000..4678b30 --- /dev/null +++ b/drivers/clocksource/moxart_timer.c @@ -0,0 +1,166 @@ +/* + * MOXA ART SoCs timer handling. + * + * Copyright (C) 2013 Jonas Jensen + * + * Jonas Jensen + * + * This file is licensed under the terms of the GNU General Public + * License version 2. This program is licensed "as is" without any + * warranty of any kind, whether express or implied. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define TIMER1_BASE 0x00 +#define TIMER2_BASE 0x10 +#define TIMER3_BASE 0x20 + +#define REG_COUNT 0x0 /* writable */ +#define REG_LOAD 0x4 +#define REG_MATCH1 0x8 +#define REG_MATCH2 0xC + +#define TIMER_CR 0x30 +#define TIMER_INTR_STATE 0x34 +#define TIMER_INTR_MASK 0x38 + +/* + * TIMER_CR flags: + * + * TIMEREG_CR_*_CLOCK 0: PCLK, 1: EXT1CLK + * TIMEREG_CR_*_INT overflow interrupt enable bit + */ +#define TIMEREG_CR_1_ENABLE (1 << 0) +#define TIMEREG_CR_1_CLOCK (1 << 1) +#define TIMEREG_CR_1_INT (1 << 2) +#define TIMEREG_CR_2_ENABLE (1 << 3) +#define TIMEREG_CR_2_CLOCK (1 << 4) +#define TIMEREG_CR_2_INT (1 << 5) +#define TIMEREG_CR_3_ENABLE (1 << 6) +#define TIMEREG_CR_3_CLOCK (1 << 7) +#define TIMEREG_CR_3_INT (1 << 8) +#define TIMEREG_CR_COUNT_UP (1 << 9) +#define TIMEREG_CR_COUNT_DOWN (0 << 9) + +static void __iomem *base; +static unsigned int clock_count_per_tick; + +static void moxart_clkevt_mode(enum clock_event_mode mode, + struct clock_event_device *clk) +{ + u32 u = readl(base + TIMER_CR); + + switch (mode) { + case CLOCK_EVT_MODE_RESUME: + case CLOCK_EVT_MODE_ONESHOT: + u &= ~TIMEREG_CR_1_ENABLE; + writel(u, base + TIMER_CR); + writel(~0, base + TIMER1_BASE + REG_LOAD); + break; + case CLOCK_EVT_MODE_PERIODIC: + writel(clock_count_per_tick, base + TIMER1_BASE + REG_LOAD); + u |= TIMEREG_CR_1_ENABLE; + writel(u, base + TIMER_CR); + break; + case CLOCK_EVT_MODE_UNUSED: + case CLOCK_EVT_MODE_SHUTDOWN: + default: + u &= ~TIMEREG_CR_1_ENABLE; + writel(u, base + TIMER_CR); + break; + } +} + +static int moxart_clkevt_next_event(unsigned long cycles, + struct clock_event_device *unused) +{ + u32 u; + u = readl(base + TIMER1_BASE + REG_COUNT) - cycles; + writel(u, base + TIMER1_BASE + REG_MATCH1); + u = readl(base + TIMER_CR) | TIMEREG_CR_1_ENABLE; + writel(u, base + TIMER_CR); + return 0; +} + +static struct clock_event_device moxart_clockevent = { + .name = "moxart_timer", + .rating = 200, + .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT, + .set_mode = moxart_clkevt_mode, + .set_next_event = moxart_clkevt_next_event, +}; + +static irqreturn_t moxart_timer_interrupt(int irq, void *dev_id) +{ + struct clock_event_device *evt = dev_id; + evt->event_handler(evt); + return IRQ_HANDLED; +} + +static struct irqaction moxart_timer_irq = { + .name = "moxart-timer", + .flags = IRQF_TIMER, + .handler = moxart_timer_interrupt, + .dev_id = &moxart_clockevent, +}; + +static void __init moxart_timer_init(struct device_node *node) +{ + int ret, irq; + unsigned long pclk; + struct clk *clk; + + base = of_iomap(node, 0); + if (!base) + panic("%s: failed to map base\n", node->full_name); + + irq = irq_of_parse_and_map(node, 0); + if (irq <= 0) + panic("%s: can't parse IRQ\n", node->full_name); + + ret = setup_irq(irq, &moxart_timer_irq); + if (ret) { + pr_err("%s: failed to setup IRQ %d\n", node->full_name, irq); + return; + } + + clk = of_clk_get(node, 0); + if (IS_ERR(clk)) { + pr_err("%s: of_clk_get failed\n", __func__); + return; + } + + pclk = clk_get_rate(clk); + clock_count_per_tick = DIV_ROUND_CLOSEST(pclk, HZ); + + writel(~0, base + TIMER2_BASE + REG_LOAD); + + writel(TIMEREG_CR_2_ENABLE, base + TIMER_CR); + + if (clocksource_mmio_init(base + TIMER2_BASE + REG_COUNT, + "moxart_timer", pclk, 200, 32, + clocksource_mmio_readl_down)) { + pr_err("%s: clocksource_mmio_init failed\n", __func__); + return; + } + + moxart_clockevent.cpumask = cpumask_of(0); + + clockevents_config_and_register(&moxart_clockevent, pclk, + 0x4, 0xf0000000); + + pr_info("%s: %s finished pclk=%lu HZ=%d IRQ=%d\n", + node->full_name, __func__, pclk, HZ, irq); +} +CLOCKSOURCE_OF_DECLARE(moxart, "moxa,moxart-timer", moxart_timer_init); + -- 1.8.2.1 -- 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/