From patchwork Thu Jul 20 11:29:09 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nikita Shubin via B4 Relay X-Patchwork-Id: 13320031 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 681DA17735 for ; Thu, 20 Jul 2023 08:30:00 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPS id 13A46C611B1; Thu, 20 Jul 2023 08:29:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1689841797; bh=oVNeIVS24ovp4Bk+ISFEomvXaLIJWv1HRJzkQJqBfRQ=; h=From:Date:Subject:References:In-Reply-To:List-Id:To:Cc:Reply-To: From; b=KCBY6T8jZoZJxHtceySUtnED/DFBapt8mwpRyoidcLAoN7En07izu678qZgF+7Z27 l298VIcjgw6HWMmYeaeoiL8qN9y3mWe3SrOQcBH9AkSGodUo8zlaDZ2zOencSM6yHN qDwFFJ2Rj53K0vohrq9R7vznDbrBEwMwVmazzWkRD0nYMkV5ZY89ZSaWbzKNJCYpf9 BB0V3+aWNf/6nB/hUEMVBncSNtbtxAzZSLSrNhHJQKQewLE7SueZZAoGYNnLjAC2Bd DK+gA81+4QX3bLGBxAFCeip/zJODwjwNyvBJk94QYpoBjvVoSp6FuDAckjNvsIkkKG kF6NDoGYNsIGQ== Received: from aws-us-west-2-korg-lkml-1.web.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.lore.kernel.org (Postfix) with ESMTP id E4A0CC04A6A; Thu, 20 Jul 2023 08:29:56 +0000 (UTC) From: Nikita Shubin via B4 Relay Date: Thu, 20 Jul 2023 14:29:09 +0300 Subject: [PATCH v3 09/42] clocksource: ep93xx: Add driver for Cirrus Logic EP93xx Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20230605-ep93xx-v3-9-3d63a5f1103e@maquefel.me> References: <20230605-ep93xx-v3-0-3d63a5f1103e@maquefel.me> In-Reply-To: <20230605-ep93xx-v3-0-3d63a5f1103e@maquefel.me> List-Id: To: Hartley Sweeten , Lennert Buytenhek , Alexander Sverdlin , Russell King , Lukasz Majewski , Linus Walleij , Bartosz Golaszewski , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Michael Turquette , Stephen Boyd , Nikita Shubin , Daniel Lezcano , Thomas Gleixner , Alessandro Zummo , Alexandre Belloni , Wim Van Sebroeck , Guenter Roeck , Sebastian Reichel , Thierry Reding , =?utf-8?q?Uwe_Kleine-K=C3=B6nig?= , Mark Brown , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Vinod Koul , Miquel Raynal , Richard Weinberger , Vignesh Raghavendra , Damien Le Moal , Sergey Shtylyov , Dmitry Torokhov , Arnd Bergmann , Olof Johansson , soc@kernel.org, Liam Girdwood , Jaroslav Kysela , Takashi Iwai , Andy Shevchenko , Michael Peters , Kris Bahnsen Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-gpio@vger.kernel.org, devicetree@vger.kernel.org, linux-clk@vger.kernel.org, linux-rtc@vger.kernel.org, linux-watchdog@vger.kernel.org, linux-pm@vger.kernel.org, linux-pwm@vger.kernel.org, linux-spi@vger.kernel.org, netdev@vger.kernel.org, dmaengine@vger.kernel.org, linux-mtd@lists.infradead.org, linux-ide@vger.kernel.org, linux-input@vger.kernel.org, alsa-devel@alsa-project.org X-Mailer: b4 0.12.1 X-Developer-Signature: v=1; a=ed25519-sha256; t=1689852590; l=7745; i=nikita.shubin@maquefel.me; s=20230718; h=from:subject:message-id; bh=91Q5aMzQnMojBq/wb/TN2iHaQ2aIwhcgyrmryexjCyI=; =?utf-8?q?b=3DHp6WdlCpm0lC?= =?utf-8?q?cc/mcEspfz8iFJawc6l5cUt94y0Gy1DG3lV2KIP6JxJWk7f1PGp0vyp+MKaNfnu+?= XsyKVE8GDkT67OsMAjVMY51W60b8iRTCuQc9hjnYXmJXzEKEfhMU X-Developer-Key: i=nikita.shubin@maquefel.me; a=ed25519; pk=vqf5YIUJ7BJv3EJFaNNxWZgGuMgDH6rwufTLflwU9ac= X-Endpoint-Received: by B4 Relay for nikita.shubin@maquefel.me/20230718 with auth_id=65 X-Original-From: Nikita Shubin Reply-To: From: Nikita Shubin This us a rewrite of EP93xx timer driver in arch/arm/mach-ep93xx/timer-ep93xx.c trying to do everything the device tree way: - Make every IO-access relative to a base address and dynamic so we can do a dynamic ioremap and get going. - Find register range and interrupt from the device tree. Reviewed-by: Linus Walleij Tested-by: Alexander Sverdlin Signed-off-by: Nikita Shubin --- drivers/clocksource/Kconfig | 11 +++ drivers/clocksource/Makefile | 1 + drivers/clocksource/timer-ep93xx.c | 190 +++++++++++++++++++++++++++++++++++++ 3 files changed, 202 insertions(+) diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig index c4d671a5a13d..f1b84b05b281 100644 --- a/drivers/clocksource/Kconfig +++ b/drivers/clocksource/Kconfig @@ -739,4 +739,15 @@ config GOLDFISH_TIMER help Support for the timer/counter of goldfish-rtc +config EP93XX_TIMER + bool "Cirrus Logic ep93xx timer driver" if COMPILE_TEST + depends on ARCH_EP93XX + depends on GENERIC_CLOCKEVENTS + depends on HAS_IOMEM + select CLKSRC_MMIO + select TIMER_OF + help + Enables support for the Cirrus Logic timer block + EP93XX. + endmenu diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile index 5d93c9e3fc55..b6a3cf1f5b9d 100644 --- a/drivers/clocksource/Makefile +++ b/drivers/clocksource/Makefile @@ -90,3 +90,4 @@ obj-$(CONFIG_MSC313E_TIMER) += timer-msc313e.o obj-$(CONFIG_GOLDFISH_TIMER) += timer-goldfish.o obj-$(CONFIG_GXP_TIMER) += timer-gxp.o obj-$(CONFIG_CLKSRC_LOONGSON1_PWM) += timer-loongson1-pwm.o +obj-$(CONFIG_EP93XX_TIMER) += timer-ep93xx.o diff --git a/drivers/clocksource/timer-ep93xx.c b/drivers/clocksource/timer-ep93xx.c new file mode 100644 index 000000000000..bc0ca6e12334 --- /dev/null +++ b/drivers/clocksource/timer-ep93xx.c @@ -0,0 +1,190 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Cirrus Logic EP93xx timer driver. + * Copyright (C) 2021 Nikita Shubin + * + * Based on a rewrite of arch/arm/mach-ep93xx/timer.c: + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +/************************************************************************* + * Timer handling for EP93xx + ************************************************************************* + * The ep93xx has four internal timers. Timers 1, 2 (both 16 bit) and + * 3 (32 bit) count down at 508 kHz, are self-reloading, and can generate + * an interrupt on underflow. Timer 4 (40 bit) counts down at 983.04 kHz, + * is free-running, and can't generate interrupts. + * + * The 508 kHz timers are ideal for use for the timer interrupt, as the + * most common values of HZ divide 508 kHz nicely. We pick the 32 bit + * timer (timer 3) to get as long sleep intervals as possible when using + * CONFIG_NO_HZ. + * + * The higher clock rate of timer 4 makes it a better choice than the + * other timers for use as clock source and for sched_clock(), providing + * a stable 40 bit time base. + ************************************************************************* + */ + +#define EP93XX_TIMER1_LOAD 0x00 +#define EP93XX_TIMER1_VALUE 0x04 +#define EP93XX_TIMER1_CONTROL 0x08 +#define EP93XX_TIMER123_CONTROL_ENABLE BIT(7) +#define EP93XX_TIMER123_CONTROL_MODE BIT(6) +#define EP93XX_TIMER123_CONTROL_CLKSEL BIT(3) +#define EP93XX_TIMER1_CLEAR 0x0c +#define EP93XX_TIMER2_LOAD 0x20 +#define EP93XX_TIMER2_VALUE 0x24 +#define EP93XX_TIMER2_CONTROL 0x28 +#define EP93XX_TIMER2_CLEAR 0x2c +/* + * This read-only register contains the low word of the time stamp debug timer + * ( Timer4). When this register is read, the high byte of the Timer4 counter is + * saved in the Timer4ValueHigh register. + */ +#define EP93XX_TIMER4_VALUE_LOW 0x60 +#define EP93XX_TIMER4_VALUE_HIGH 0x64 +#define EP93XX_TIMER4_VALUE_HIGH_ENABLE BIT(8) +#define EP93XX_TIMER3_LOAD 0x80 +#define EP93XX_TIMER3_VALUE 0x84 +#define EP93XX_TIMER3_CONTROL 0x88 +#define EP93XX_TIMER3_CLEAR 0x8c + +#define EP93XX_TIMER123_RATE 508469 +#define EP93XX_TIMER4_RATE 983040 + +struct ep93xx_tcu { + void __iomem *base; +}; + +static struct ep93xx_tcu *ep93xx_tcu; + +static u64 ep93xx_clocksource_read(struct clocksource *c) +{ + struct ep93xx_tcu *tcu = ep93xx_tcu; + + return lo_hi_readq(tcu->base + EP93XX_TIMER4_VALUE_LOW) & GENMASK_ULL(39, 0); +} + +static u64 notrace ep93xx_read_sched_clock(void) +{ + return ep93xx_clocksource_read(NULL); +} + +static int ep93xx_clkevt_set_next_event(unsigned long next, + struct clock_event_device *evt) +{ + struct ep93xx_tcu *tcu = ep93xx_tcu; + /* Default mode: periodic, off, 508 kHz */ + u32 tmode = EP93XX_TIMER123_CONTROL_MODE | + EP93XX_TIMER123_CONTROL_CLKSEL; + + /* Clear timer */ + writel(tmode, tcu->base + EP93XX_TIMER3_CONTROL); + + /* Set next event */ + writel(next, tcu->base + EP93XX_TIMER3_LOAD); + writel(tmode | EP93XX_TIMER123_CONTROL_ENABLE, + tcu->base + EP93XX_TIMER3_CONTROL); + return 0; +} + +static int ep93xx_clkevt_shutdown(struct clock_event_device *evt) +{ + struct ep93xx_tcu *tcu = ep93xx_tcu; + /* Disable timer */ + writel(0, tcu->base + EP93XX_TIMER3_CONTROL); + + return 0; +} + +static struct clock_event_device ep93xx_clockevent = { + .name = "timer1", + .features = CLOCK_EVT_FEAT_ONESHOT, + .set_state_shutdown = ep93xx_clkevt_shutdown, + .set_state_oneshot = ep93xx_clkevt_shutdown, + .tick_resume = ep93xx_clkevt_shutdown, + .set_next_event = ep93xx_clkevt_set_next_event, + .rating = 300, +}; + +static irqreturn_t ep93xx_timer_interrupt(int irq, void *dev_id) +{ + struct ep93xx_tcu *tcu = ep93xx_tcu; + struct clock_event_device *evt = dev_id; + + /* Writing any value clears the timer interrupt */ + writel(1, tcu->base + EP93XX_TIMER3_CLEAR); + + evt->event_handler(evt); + + return IRQ_HANDLED; +} + +static int __init ep93xx_timer_of_init(struct device_node *np) +{ + int irq; + unsigned long flags = IRQF_TIMER | IRQF_IRQPOLL; + struct ep93xx_tcu *tcu; + int ret; + + tcu = kzalloc(sizeof(*tcu), GFP_KERNEL); + if (!tcu) + return -ENOMEM; + + tcu->base = of_iomap(np, 0); + if (!tcu->base) { + pr_err("Can't remap registers\n"); + ret = -ENXIO; + goto out_free; + } + + ep93xx_tcu = tcu; + + irq = irq_of_parse_and_map(np, 0); + if (irq == 0) + irq = -EINVAL; + if (irq < 0) { + pr_err("EP93XX Timer Can't parse IRQ %d", irq); + goto out_free; + } + + /* Enable and register clocksource and sched_clock on timer 4 */ + writel(EP93XX_TIMER4_VALUE_HIGH_ENABLE, + tcu->base + EP93XX_TIMER4_VALUE_HIGH); + clocksource_mmio_init(NULL, "timer4", + EP93XX_TIMER4_RATE, 200, 40, + ep93xx_clocksource_read); + sched_clock_register(ep93xx_read_sched_clock, 40, + EP93XX_TIMER4_RATE); + + /* Set up clockevent on timer 3 */ + if (request_irq(irq, ep93xx_timer_interrupt, flags, "ep93xx timer", + &ep93xx_clockevent)) + pr_err("Failed to request irq %d (ep93xx timer)\n", irq); + + clockevents_config_and_register(&ep93xx_clockevent, + EP93XX_TIMER123_RATE, + 1, + UINT_MAX); + + return 0; + +out_free: + kfree(tcu); + return ret; +} +TIMER_OF_DECLARE(ep93xx_timer, "cirrus,ep9301-timer", ep93xx_timer_of_init);