Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752755AbdLHIUy (ORCPT ); Fri, 8 Dec 2017 03:20:54 -0500 Received: from mail-oi0-f68.google.com ([209.85.218.68]:37853 "EHLO mail-oi0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751021AbdLHIUw (ORCPT ); Fri, 8 Dec 2017 03:20:52 -0500 X-Google-Smtp-Source: AGs4zMYSFQ0I3djp2AE5SL8co5UMHjON3T+6YSSlc57qds7NH6WpjzyI1YEaydbx7q1SVlndcXCg5i8X6jVJlTz4+cU= MIME-Version: 1.0 In-Reply-To: <05f19500-f8a3-7afc-a8d9-bcf0aff3e6bc@linaro.org> References: <1b80566bd849d68b0fc8de54ecbbc7b4efbb1077.1512708743.git.baolin.wang@spreadtrum.com> <05f19500-f8a3-7afc-a8d9-bcf0aff3e6bc@linaro.org> From: Baolin Wang Date: Fri, 8 Dec 2017 16:20:51 +0800 Message-ID: Subject: Re: [PATCH v3 2/2] clocksource: sprd: Add timer driver for Spreadtrum SC9860 platform To: Daniel Lezcano Cc: Baolin Wang , Thomas Gleixner , Rob Herring , Mark Rutland , DTML , LKML , Mark Brown Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 8101 Lines: 251 Hi Daniel, On 8 December 2017 at 14:58, Daniel Lezcano wrote: > On 08/12/2017 06:03, Baolin Wang wrote: >> The Spreadtrum SC9860 platform will use the architected timers as local >> clock events, but we also need a broadcast timer device to wakeup the >> cpus when the cpus are in sleep mode. >> >> The Spreadtrum timer can support 32bit or 64bit counter, as well as >> supporting period mode or one-shot mode. >> >> Signed-off-by: Baolin Wang >> --- >> Changes since v2: >> - Add more timer description in changelog. >> - Rename the driver file. >> - Remove GENERIC_CLOCKEVENTS and ARCH_SPRD dependency. >> - Remove some redundant headfiles. >> - Use timer-of APIs. >> - Change the license format according to Linus[1][2][3], >> Thomas[4] and Greg[5] comments on the topic. >> [1] https://lkml.org/lkml/2017/11/2/715 >> [2] https://lkml.org/lkml/2017/11/25/125 >> [3] https://lkml.org/lkml/2017/11/25/133 >> [4] https://lkml.org/lkml/2017/11/2/805 >> [5] https://lkml.org/lkml/2017/10/19/165 >> >> Changes since v1: >> - Change to 32bit counter to avoid build warning. >> --- >> drivers/clocksource/Kconfig | 7 ++ >> drivers/clocksource/Makefile | 1 + >> drivers/clocksource/timer-sprd.c | 168 ++++++++++++++++++++++++++++++++++++++ >> 3 files changed, 176 insertions(+) >> create mode 100644 drivers/clocksource/timer-sprd.c >> >> diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig >> index c729a88..9a6b087 100644 >> --- a/drivers/clocksource/Kconfig >> +++ b/drivers/clocksource/Kconfig >> @@ -441,6 +441,13 @@ config MTK_TIMER >> help >> Support for Mediatek timer driver. >> >> +config SPRD_TIMER >> + bool "Spreadtrum timer driver" if COMPILE_TEST >> + depends on HAS_IOMEM >> + select TIMER_OF >> + help >> + Enables the support for the Spreadtrum timer driver. >> + >> config SYS_SUPPORTS_SH_MTU2 >> bool >> >> diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile >> index 72711f1..d6dec44 100644 >> --- a/drivers/clocksource/Makefile >> +++ b/drivers/clocksource/Makefile >> @@ -54,6 +54,7 @@ obj-$(CONFIG_CLKSRC_TI_32K) += timer-ti-32k.o >> obj-$(CONFIG_CLKSRC_NPS) += timer-nps.o >> obj-$(CONFIG_OXNAS_RPS_TIMER) += timer-oxnas-rps.o >> obj-$(CONFIG_OWL_TIMER) += owl-timer.o >> +obj-$(CONFIG_SPRD_TIMER) += timer-sprd.o >> >> obj-$(CONFIG_ARC_TIMERS) += arc_timer.o >> obj-$(CONFIG_ARM_ARCH_TIMER) += arm_arch_timer.o >> diff --git a/drivers/clocksource/timer-sprd.c b/drivers/clocksource/timer-sprd.c >> new file mode 100644 >> index 0000000..81a5f0c >> --- /dev/null >> +++ b/drivers/clocksource/timer-sprd.c >> @@ -0,0 +1,168 @@ >> +// SPDX-License-Identifier: GPL-2.0 >> +/* >> + * Copyright (C) 2017 Spreadtrum Communications Inc. >> + */ >> + >> +#include >> +#include >> + >> +#include "timer-of.h" >> + >> +#define TIMER_NAME "sprd_timer" >> + >> +#define TIMER_LOAD_LO 0x0 >> +#define TIMER_LOAD_HI 0x4 >> +#define TIMER_VALUE_LO 0x8 >> +#define TIMER_VALUE_HI 0xc >> + >> +#define TIMER_CTL 0x10 >> +#define TIMER_CTL_PERIOD_MODE BIT(0) >> +#define TIMER_CTL_ENABLE BIT(1) >> +#define TIMER_CTL_64BIT_WIDTH BIT(16) >> + >> +#define TIMER_INT 0x14 >> +#define TIMER_INT_EN BIT(0) >> +#define TIMER_INT_RAW_STS BIT(1) >> +#define TIMER_INT_MASK_STS BIT(2) >> +#define TIMER_INT_CLR BIT(3) >> + >> +#define TIMER_VALUE_SHDW_LO 0x18 >> +#define TIMER_VALUE_SHDW_HI 0x1c >> + >> +#define TIMER_VALUE_LO_MASK GENMASK(31, 0) >> + >> +static void sprd_timer_enable(void __iomem *base, u32 flag) >> +{ >> + u32 val = readl_relaxed(base + TIMER_CTL); >> + >> + val |= TIMER_CTL_ENABLE; >> + if (flag & TIMER_CTL_64BIT_WIDTH) >> + val |= TIMER_CTL_64BIT_WIDTH; >> + else >> + val &= ~TIMER_CTL_64BIT_WIDTH; >> + >> + if (flag & TIMER_CTL_PERIOD_MODE) >> + val |= TIMER_CTL_PERIOD_MODE; >> + else >> + val &= ~TIMER_CTL_PERIOD_MODE; >> + >> + writel_relaxed(val, base + TIMER_CTL); >> +} >> + >> +static void sprd_timer_disable(void __iomem *base) >> +{ >> + u32 val = readl_relaxed(base + TIMER_CTL); >> + >> + val &= ~TIMER_CTL_ENABLE; >> + writel_relaxed(val, base + TIMER_CTL); >> +} >> + >> +static void sprd_timer_update_counter(void __iomem *base, unsigned long cycles) >> +{ >> + writel_relaxed(cycles & TIMER_VALUE_LO_MASK, base + TIMER_LOAD_LO); >> + writel_relaxed(0, base + TIMER_LOAD_HI); >> +} >> + >> +static void sprd_timer_enable_interrupt(void __iomem *base) >> +{ >> + writel_relaxed(TIMER_INT_EN, base + TIMER_INT); >> +} >> + >> +static void sprd_timer_clear_interrupt(void __iomem *base) >> +{ >> + u32 val = readl_relaxed(base + TIMER_INT); >> + >> + val |= TIMER_INT_CLR; >> + writel_relaxed(val, base + TIMER_INT); >> +} >> + >> +static int sprd_timer_set_next_event(unsigned long cycles, >> + struct clock_event_device *ce) >> +{ >> + struct timer_of *to = to_timer_of(ce); >> + >> + sprd_timer_disable(timer_of_base(to)); >> + sprd_timer_update_counter(timer_of_base(to), cycles); >> + sprd_timer_enable(timer_of_base(to), 0); >> + >> + return 0; >> +} >> + >> +static int sprd_timer_set_periodic(struct clock_event_device *ce) >> +{ >> + struct timer_of *to = to_timer_of(ce); >> + >> + sprd_timer_disable(timer_of_base(to)); >> + sprd_timer_update_counter(timer_of_base(to), timer_of_period(to)); >> + sprd_timer_enable(timer_of_base(to), TIMER_CTL_PERIOD_MODE); >> + >> + return 0; >> +} >> + >> +static int sprd_timer_shutdown(struct clock_event_device *ce) >> +{ >> + struct timer_of *to = to_timer_of(ce); >> + >> + sprd_timer_disable(timer_of_base(to)); >> + return 0; >> +} >> + >> +static irqreturn_t sprd_timer_interrupt(int irq, void *dev_id) >> +{ >> + struct clock_event_device *ce = (struct clock_event_device *)dev_id; >> + struct timer_of *to = to_timer_of(ce); >> + >> + sprd_timer_clear_interrupt(timer_of_base(to)); >> + >> + if (clockevent_state_oneshot(ce)) >> + sprd_timer_disable(timer_of_base(to)); >> + >> + ce->event_handler(ce); >> + return IRQ_HANDLED; >> +} >> + >> +static struct timer_of to = { >> + .flags = TIMER_OF_IRQ | TIMER_OF_BASE, > > Why not the TIMER_OF_CLOCK ? The timer's clock is fixed to 32.768K and no need to divide the frequency, so our clock tree does not supply the timer's clock now. >> + >> + .clkevt = { >> + .name = TIMER_NAME, >> + .rating = 300, >> + .features = CLOCK_EVT_FEAT_DYNIRQ | CLOCK_EVT_FEAT_PERIODIC | >> + CLOCK_EVT_FEAT_ONESHOT, >> + .set_state_shutdown = sprd_timer_shutdown, >> + .set_state_periodic = sprd_timer_set_periodic, >> + .set_next_event = sprd_timer_set_next_event, >> + .cpumask = cpu_possible_mask, >> + }, >> + >> + .of_irq = { >> + .handler = sprd_timer_interrupt, >> + .flags = IRQF_TIMER | IRQF_IRQPOLL, >> + }, >> +}; >> + >> +static int __init sprd_timer_init(struct device_node *np) >> +{ >> + int ret; >> + u32 freq; >> + >> + ret = timer_of_init(np, &to); >> + if (ret) >> + return ret; >> + >> + ret = of_property_read_u32(np, "clock-frequency", &freq); >> + if (ret) { >> + pr_err("failed to get clock frequency\n"); >> + timer_of_cleanup(&to); >> + return ret; >> + } >> + >> + to.of_clk.period = DIV_ROUND_UP(freq, HZ); >> + >> + sprd_timer_enable_interrupt(timer_of_base(&to)); >> + clockevents_config_and_register(&to.clkevt, freq, 1, UINT_MAX); >> + >> + return 0; >> +} >> + >> +TIMER_OF_DECLARE(sc9860_timer, "sprd,sc9860-timer", sprd_timer_init); >> -- Baolin.wang Best Regards