From patchwork Fri Jun 21 04:27:35 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chris Packham X-Patchwork-Id: 13706789 Received: from gate2.alliedtelesis.co.nz (gate2.alliedtelesis.co.nz [202.36.163.20]) (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 E0CF412C7FF for ; Fri, 21 Jun 2024 04:27:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=202.36.163.20 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718944079; cv=none; b=a+97+q4tnchobfQNzUC6VBoSBtrmv/RCNag11PjX/ij7CPIoA0dJG0rRRpxT5IwyIlA6jKz4+3T8oa4NJ0PVoCP0l1oz6Gv+NUgbC839PcJpKwmFF11i5cwlpqn2UiMyLbiWdsFfawafxecgIroMcrWZBzb2BeWoYkMtx+sqAZo= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718944079; c=relaxed/simple; bh=9frSEnlTnP7IUmlF4RoHML58Wakk9VcRmpssS8TkHPU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=vFh8MzIpfwN4buaAmbVU7X48ezNjs8ONdCCWNXdaSM2/AzXROW8KmQyDX7X+dD8Z1JFGUGtNSVn/EMHiZlwddcZlZf2iH9c8w8kmHlI0IRaX9h+tg7T5Bgbx03fVzecxyXmGbmSyA5gCbPEfPkXz8WjIsmmT9gTiiV0o9i2CTeQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=alliedtelesis.co.nz; spf=pass smtp.mailfrom=alliedtelesis.co.nz; dkim=pass (2048-bit key) header.d=alliedtelesis.co.nz header.i=@alliedtelesis.co.nz header.b=lfLwtRJ4; arc=none smtp.client-ip=202.36.163.20 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=alliedtelesis.co.nz Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=alliedtelesis.co.nz Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=alliedtelesis.co.nz header.i=@alliedtelesis.co.nz header.b="lfLwtRJ4" Received: from svr-chch-seg1.atlnz.lc (mmarshal3.atlnz.lc [10.32.18.43]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by gate2.alliedtelesis.co.nz (Postfix) with ESMTPS id 137752C0506; Fri, 21 Jun 2024 16:27:45 +1200 (NZST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alliedtelesis.co.nz; s=mail181024; t=1718944065; bh=Tl1j/fhtEchUHndZYnpF7xflboInSYHUPRDutHTCOLA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=lfLwtRJ4Zwi1dXpZJfU98GJxH5Bf9e6J3JPVMs14D268iKmdOixubsi+k6LhSHIyv 74QWcLScG/ePFp3k2zHd/y+Vm+7SuFPPz18f5wbWqEeaKn+hh6WjE9n6Rde91tPcAt Pw5F0pCed5y7jEuXoX9tlb026GvwsxNJXRF/ZehYdWI8m7h5feZ4Bb0+meRaZjk81l CuyCbbpZnT84wbQnb4xxsNp035RhpX5S9RcsYE0yJD115X0cKPsaZ3t2b0ALw4LU/G 50gyYX5BU+NAuFtv0lW0m4XSLwOyKC5Up1O+jF3b8bLfSvObrRLcKxzgWWGerjikRU xQJWdPuOXm6Ug== Received: from pat.atlnz.lc (Not Verified[10.32.16.33]) by svr-chch-seg1.atlnz.lc with Trustwave SEG (v8,2,6,11305) id ; Fri, 21 Jun 2024 16:27:44 +1200 Received: from chrisp-dl.ws.atlnz.lc (chrisp-dl.ws.atlnz.lc [10.33.22.30]) by pat.atlnz.lc (Postfix) with ESMTP id 53DDE13EDC3; Fri, 21 Jun 2024 16:27:44 +1200 (NZST) Received: by chrisp-dl.ws.atlnz.lc (Postfix, from userid 1030) id 51AC7280BEA; Fri, 21 Jun 2024 16:27:44 +1200 (NZST) From: Chris Packham To: tglx@linutronix.de, robh@kernel.org, krzk+dt@kernel.org, conor+dt@kernel.org, tsbogend@alpha.franken.de, daniel.lezcano@linaro.org, paulburton@kernel.org, peterz@infradead.org, mail@birger-koblitz.de, bert@biot.com, john@phrozen.org, sander@svanheule.net Cc: linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, linux-mips@vger.kernel.org, kabel@kernel.org, ericwouds@gmail.com, Chris Packham , Markus Stockhausen Subject: [PATCH 4/6] clocksource: realtek: Add timer driver for rtl-otto platforms Date: Fri, 21 Jun 2024 16:27:35 +1200 Message-ID: <20240621042737.674128-5-chris.packham@alliedtelesis.co.nz> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240621042737.674128-1-chris.packham@alliedtelesis.co.nz> References: <20240621042737.674128-1-chris.packham@alliedtelesis.co.nz> Precedence: bulk X-Mailing-List: linux-mips@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-SEG-SpamProfiler-Analysis: v=2.4 cv=CvQccW4D c=1 sm=1 tr=0 ts=66750140 a=KLBiSEs5mFS1a/PbTCJxuA==:117 a=T1WGqf2p2xoA:10 a=jU52IrjdAAAA:8 a=jdP34snFAAAA:8 a=lYcVSoeQvU4dK_rf-5cA:9 a=3ZKOabzyN94A:10 a=udjdHy_fWrGJRxLc5KTh:22 a=jlphF6vWLdwq7oh3TaWq:22 X-SEG-SpamProfiler-Score: 0 x-atlnz-ls: pat The timer/counter block on the Realtek SoCs provides up to 5 timers. It also includes a watchdog timer but this isn't being used currently (it will be added as a separate wdt driver). One timer will be used per CPU as a local clock event generator. An additional timer will be used as an overal stable clocksource. Signed-off-by: Markus Stockhausen Signed-off-by: Sander Vanheule Signed-off-by: Chris Packham --- Notes: This is derrived from openwrt[1],[2]. I've retained the original signoff and added my own. [1] https://git.openwrt.org/?p=openwrt/openwrt.git;a=blob_plain;f=target/linux/realtek/files-5.15/drivers/clocksource/timer-rtl-otto.c;hb=HEAD [2] https://git.openwrt.org/?p=openwrt/openwrt.git;a=blob_plain;f=target/linux/realtek/patches-5.15/302-clocksource-add-otto-driver.patch;hb=HEAD drivers/clocksource/Kconfig | 11 + drivers/clocksource/Makefile | 1 + drivers/clocksource/timer-rtl-otto.c | 287 +++++++++++++++++++++++++++ include/linux/cpuhotplug.h | 1 + 4 files changed, 300 insertions(+) create mode 100644 drivers/clocksource/timer-rtl-otto.c diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig index 34faa0320ece..f02b5b50d166 100644 --- a/drivers/clocksource/Kconfig +++ b/drivers/clocksource/Kconfig @@ -134,6 +134,17 @@ config RDA_TIMER help Enables the support for the RDA Micro timer driver. +config REALTEK_OTTO_TIMER + bool "Clocksource/timer for the Realtek Otto platform" + select COMMON_CLK + select TIMER_OF + help + This driver adds support for the timers found in the Realtek RTL83xx + and RTL93xx SoCs series. This includes chips such as RTL8380, RTL8381 + and RTL832, as well as chips from the RTL839x series, such as RTL8390 + RT8391, RTL8392, RTL8393 and RTL8396 and chips of the RTL930x series + such as RTL9301, RTL9302 or RTL9303. + config SUN4I_TIMER bool "Sun4i timer driver" if COMPILE_TEST depends on HAS_IOMEM diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile index 4bb856e4df55..22743785299e 100644 --- a/drivers/clocksource/Makefile +++ b/drivers/clocksource/Makefile @@ -59,6 +59,7 @@ obj-$(CONFIG_MILBEAUT_TIMER) += timer-milbeaut.o obj-$(CONFIG_SPRD_TIMER) += timer-sprd.o obj-$(CONFIG_NPCM7XX_TIMER) += timer-npcm7xx.o obj-$(CONFIG_RDA_TIMER) += timer-rda.o +obj-$(CONFIG_REALTEK_OTTO_TIMER) += timer-rtl-otto.o obj-$(CONFIG_ARC_TIMERS) += arc_timer.o obj-$(CONFIG_ARM_ARCH_TIMER) += arm_arch_timer.o diff --git a/drivers/clocksource/timer-rtl-otto.c b/drivers/clocksource/timer-rtl-otto.c new file mode 100644 index 000000000000..7e41ae95d7dc --- /dev/null +++ b/drivers/clocksource/timer-rtl-otto.c @@ -0,0 +1,287 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include +#include +#include +#include "timer-of.h" + +#define RTTM_DATA 0x0 +#define RTTM_CNT 0x4 +#define RTTM_CTRL 0x8 +#define RTTM_INT 0xc + +#define RTTM_CTRL_ENABLE BIT(28) +#define RTTM_INT_PENDING BIT(16) +#define RTTM_INT_ENABLE BIT(20) + +/* + * The Otto platform provides multiple 28 bit timers/counters with the following + * operating logic. If enabled the timer counts up. Per timer one can set a + * maximum counter value as an end marker. If end marker is reached the timer + * fires an interrupt. If the timer "overflows" by reaching the end marker or + * by adding 1 to 0x0fffffff the counter is reset to 0. When this happens and + * the timer is in operating mode COUNTER it stops. In mode TIMER it will + * continue to count up. + */ +#define RTTM_CTRL_COUNTER 0 +#define RTTM_CTRL_TIMER BIT(24) + +#define RTTM_BIT_COUNT 28 +#define RTTM_MIN_DELTA 8 +#define RTTM_MAX_DELTA CLOCKSOURCE_MASK(28) + +/* + * Timers are derived from the LXB clock frequency. Usually this is a fixed + * multiple of the 25 MHz oscillator. The 930X SOC is an exception from that. + * Its LXB clock has only dividers and uses the switch PLL of 2.45 GHz as its + * base. The only meaningful frequencies we can achieve from that are 175.000 + * MHz and 153.125 MHz. The greatest common divisor of all explained possible + * speeds is 3125000. Pin the timers to this 3.125 MHz reference frequency. + */ +#define RTTM_TICKS_PER_SEC 3125000 + +struct rttm_cs { + struct timer_of to; + struct clocksource cs; +}; + +/* Simple internal register functions */ +static inline void rttm_set_counter(void __iomem *base, unsigned int counter) +{ + iowrite32(counter, base + RTTM_CNT); +} + +static inline unsigned int rttm_get_counter(void __iomem *base) +{ + return ioread32(base + RTTM_CNT); +} + +static inline void rttm_set_period(void __iomem *base, unsigned int period) +{ + iowrite32(period, base + RTTM_DATA); +} + +static inline void rttm_disable_timer(void __iomem *base) +{ + iowrite32(0, base + RTTM_CTRL); +} + +static inline void rttm_enable_timer(void __iomem *base, u32 mode, u32 divisor) +{ + iowrite32(RTTM_CTRL_ENABLE | mode | divisor, base + RTTM_CTRL); +} + +static inline void rttm_ack_irq(void __iomem *base) +{ + iowrite32(ioread32(base + RTTM_INT) | RTTM_INT_PENDING, base + RTTM_INT); +} + +static inline void rttm_enable_irq(void __iomem *base) +{ + iowrite32(RTTM_INT_ENABLE, base + RTTM_INT); +} + +static inline void rttm_disable_irq(void __iomem *base) +{ + iowrite32(0, base + RTTM_INT); +} + +/* Aggregated control functions for kernel clock framework */ +#define RTTM_DEBUG(base) \ + pr_debug("------------- %d %08x\n", \ + smp_processor_id(), (u32)base) + +static irqreturn_t rttm_timer_interrupt(int irq, void *dev_id) +{ + struct clock_event_device *clkevt = dev_id; + struct timer_of *to = to_timer_of(clkevt); + + rttm_ack_irq(to->of_base.base); + RTTM_DEBUG(to->of_base.base); + clkevt->event_handler(clkevt); + + return IRQ_HANDLED; +} + +static void rttm_stop_timer(void __iomem *base) +{ + rttm_disable_timer(base); + rttm_ack_irq(base); +} + +static void rttm_start_timer(struct timer_of *to, u32 mode) +{ + rttm_set_counter(to->of_base.base, 0); + rttm_enable_timer(to->of_base.base, mode, to->of_clk.rate / RTTM_TICKS_PER_SEC); +} + +static int rttm_next_event(unsigned long delta, struct clock_event_device *clkevt) +{ + struct timer_of *to = to_timer_of(clkevt); + + RTTM_DEBUG(to->of_base.base); + rttm_stop_timer(to->of_base.base); + rttm_set_period(to->of_base.base, delta); + rttm_start_timer(to, RTTM_CTRL_COUNTER); + + return 0; +} + +static int rttm_state_oneshot(struct clock_event_device *clkevt) +{ + struct timer_of *to = to_timer_of(clkevt); + + RTTM_DEBUG(to->of_base.base); + rttm_stop_timer(to->of_base.base); + rttm_set_period(to->of_base.base, RTTM_TICKS_PER_SEC / HZ); + rttm_start_timer(to, RTTM_CTRL_COUNTER); + + return 0; +} + +static int rttm_state_periodic(struct clock_event_device *clkevt) +{ + struct timer_of *to = to_timer_of(clkevt); + + RTTM_DEBUG(to->of_base.base); + rttm_stop_timer(to->of_base.base); + rttm_set_period(to->of_base.base, RTTM_TICKS_PER_SEC / HZ); + rttm_start_timer(to, RTTM_CTRL_TIMER); + + return 0; +} + +static int rttm_state_shutdown(struct clock_event_device *clkevt) +{ + struct timer_of *to = to_timer_of(clkevt); + + RTTM_DEBUG(to->of_base.base); + rttm_stop_timer(to->of_base.base); + + return 0; +} + +static void rttm_setup_timer(void __iomem *base) +{ + RTTM_DEBUG(base); + rttm_stop_timer(base); + rttm_set_period(base, 0); +} + +static u64 rttm_read_clocksource(struct clocksource *cs) +{ + struct rttm_cs *rcs = container_of(cs, struct rttm_cs, cs); + + return (u64)rttm_get_counter(rcs->to.of_base.base); +} + +/* Module initialization part. */ +static DEFINE_PER_CPU(struct timer_of, rttm_to) = { + .flags = TIMER_OF_BASE | TIMER_OF_CLOCK | TIMER_OF_IRQ, + .of_irq = { + .flags = IRQF_PERCPU | IRQF_TIMER, + .handler = rttm_timer_interrupt, + }, + .clkevt = { + .rating = 400, + .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT, + .set_state_periodic = rttm_state_periodic, + .set_state_shutdown = rttm_state_shutdown, + .set_state_oneshot = rttm_state_oneshot, + .set_next_event = rttm_next_event + }, +}; + +static int rttm_enable_clocksource(struct clocksource *cs) +{ + struct rttm_cs *rcs = container_of(cs, struct rttm_cs, cs); + + rttm_disable_irq(rcs->to.of_base.base); + rttm_setup_timer(rcs->to.of_base.base); + rttm_enable_timer(rcs->to.of_base.base, RTTM_CTRL_TIMER, + rcs->to.of_clk.rate / RTTM_TICKS_PER_SEC); + + return 0; +} + +struct rttm_cs rttm_cs = { + .to = { + .flags = TIMER_OF_BASE | TIMER_OF_CLOCK, + }, + .cs = { + .name = "realtek_otto_timer", + .rating = 400, + .mask = CLOCKSOURCE_MASK(RTTM_BIT_COUNT), + .flags = CLOCK_SOURCE_IS_CONTINUOUS, + .read = rttm_read_clocksource, + } +}; + +static u64 notrace rttm_read_clock(void) +{ + return (u64)rttm_get_counter(rttm_cs.to.of_base.base); +} + +static int rttm_cpu_starting(unsigned int cpu) +{ + struct timer_of *to = per_cpu_ptr(&rttm_to, cpu); + + RTTM_DEBUG(to->of_base.base); + to->clkevt.cpumask = cpumask_of(cpu); + irq_force_affinity(to->of_irq.irq, to->clkevt.cpumask); + clockevents_config_and_register(&to->clkevt, RTTM_TICKS_PER_SEC, + RTTM_MIN_DELTA, RTTM_MAX_DELTA); + rttm_enable_irq(to->of_base.base); + + return 0; +} + +static int __init rttm_probe(struct device_node *np) +{ + int cpu, cpu_rollback; + struct timer_of *to; + int clkidx = num_possible_cpus(); + + /* Use the first n timers as per CPU clock event generators */ + for_each_possible_cpu(cpu) { + to = per_cpu_ptr(&rttm_to, cpu); + to->of_irq.index = to->of_base.index = cpu; + if (timer_of_init(np, to)) { + pr_err("setup of timer %d failed\n", cpu); + goto rollback; + } + rttm_setup_timer(to->of_base.base); + } + + /* Activate the n'th + 1 timer as a stable CPU clocksource. */ + to = &rttm_cs.to; + to->of_base.index = clkidx; + timer_of_init(np, to); + if (rttm_cs.to.of_base.base && rttm_cs.to.of_clk.rate) { + rttm_enable_clocksource(&rttm_cs.cs); + clocksource_register_hz(&rttm_cs.cs, RTTM_TICKS_PER_SEC); + sched_clock_register(rttm_read_clock, RTTM_BIT_COUNT, RTTM_TICKS_PER_SEC); + } else + pr_err(" setup of timer %d as clocksource failed", clkidx); + + return cpuhp_setup_state(CPUHP_AP_REALTEK_TIMER_STARTING, + "timer/realtek:online", + rttm_cpu_starting, NULL); +rollback: + pr_err("timer registration failed\n"); + for_each_possible_cpu(cpu_rollback) { + if (cpu_rollback == cpu) + break; + to = per_cpu_ptr(&rttm_to, cpu_rollback); + timer_of_cleanup(to); + } + + return -EINVAL; +} + +TIMER_OF_DECLARE(otto_timer, "realtek,otto-timer", rttm_probe); diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h index 7a5785f405b6..56b744dc1317 100644 --- a/include/linux/cpuhotplug.h +++ b/include/linux/cpuhotplug.h @@ -171,6 +171,7 @@ enum cpuhp_state { CPUHP_AP_ARMADA_TIMER_STARTING, CPUHP_AP_MIPS_GIC_TIMER_STARTING, CPUHP_AP_ARC_TIMER_STARTING, + CPUHP_AP_REALTEK_TIMER_STARTING, CPUHP_AP_RISCV_TIMER_STARTING, CPUHP_AP_CLINT_TIMER_STARTING, CPUHP_AP_CSKY_TIMER_STARTING,