Hi Daniel, On 7 December 2017 at 18:44, Daniel Lezcano <daniel.lezcano@xxxxxxxxxx> wrote: > On 28/11/2017 03:45, 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. >> >> Thus this patch registers the timer0 to be a broadcast timer supporting >> periodic and oneshot events. > > This changelog is inadequate. It is pointless to explain why you submit > this driver. > > It would be much more interesting to describe the timer internals. Sure. > >> Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxx> >> --- >> Changes since v1: >> - Change to 32bit counter to avoid build warning. >> --- >> drivers/clocksource/Kconfig | 8 ++ >> drivers/clocksource/Makefile | 1 + >> drivers/clocksource/sprd-timer.c | 211 ++++++++++++++++++++++++++++++++++++++ >> 3 files changed, 220 insertions(+) >> create mode 100644 drivers/clocksource/sprd-timer.c > > Even if it is not a general rule, can you rename this driver to > timer-sprd.c ? I would like little by little to converge all the timer > names to this pattern. OK. > >> diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig >> index c729a88..48c8702 100644 >> --- a/drivers/clocksource/Kconfig >> +++ b/drivers/clocksource/Kconfig >> @@ -441,6 +441,14 @@ config MTK_TIMER >> help >> Support for Mediatek timer driver. >> >> +config SPRD_TIMER >> + bool "Spreadtrum timer driver" >> + depends on GENERIC_CLOCKEVENTS > > Remove GENERIC_CLOCKEVENTS because of: > > https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git/tree/drivers/clocksource/Kconfig#n2 Yes, here GENERIC_CLOCKEVENTS is redundant. > >> + depends on ARCH_SPRD || COMPILE_TEST > > Remove the dependency on ARCH_SPRD, the arch's Kconfig must select > SPRD_TIMER. > > Move the COMPILE_TEST as the other drivers. OK. > > bool "Spreadtrum timer driver" if COMPILE_TEST > >> + select TIMER_O> + 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..62bf264 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-$(CONFIG_SPRD_TIMER) += sprd-timer.o >> >> obj-$(CONFIG_ARC_TIMERS) += arc_timer.o >> obj-$(CONFIG_ARM_ARCH_TIMER) += arm_arch_timer.o >> diff --git a/drivers/clocksource/sprd-timer.c b/drivers/clocksource/sprd-timer.c >> new file mode 100644 >> index 0000000..e90f948 >> --- /dev/null >> +++ b/drivers/clocksource/sprd-timer.c >> @@ -0,0 +1,211 @@ >> +/* >> + * Copyright (C) 2017 Spreadtrum Communications Inc. >> + * >> + * SPDX-License-Identifier: GPL-2.0 >> + */ > > Please fix the above with proper format (one example in timer-of.c). OK. > >> +#include <linux/clocksource.h> >> +#include <linux/clockchips.h> >> +#include <linux/init.h> >> +#include <linux/interrupt.h> >> +#include <linux/sched_clock.h> > > Are you sure you need sched_clock and clocksource ? Sorry, I forgot to remove them. > >> +#include <linux/slab.h> >> +#include <linux/of.h> >> +#include <linux/of_address.h> >> +#include <linux/of_irq.h> > > These headers won't be needed anymore when using the timer-of API (see > the init function comment below). OK. > >> +#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) >> + >> +struct sprd_timer_device { >> + struct clock_event_device ce; >> + void __iomem *base; >> + u32 freq; >> + int irq; >> +}; >> + >> +static inline struct sprd_timer_device * >> +to_sprd_timer(struct clock_event_device *c) >> +{ >> + return container_of(c, struct sprd_timer_device, ce); >> +} >> + >> +static void sprd_timer_enable(struct sprd_timer_device *timer, u32 flag) >> +{ >> + u32 val = readl_relaxed(timer->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, timer->base + TIMER_CTL); >> +} >> + >> +static void sprd_timer_disable(struct sprd_timer_device *timer) >> +{ >> + u32 val = readl_relaxed(timer->base + TIMER_CTL); >> + >> + val &= ~TIMER_CTL_ENABLE; >> + writel_relaxed(val, timer->base + TIMER_CTL); >> +} >> + >> +static void sprd_timer_update_counter(struct sprd_timer_device *timer, >> + unsigned long cycles) >> +{ >> + writel_relaxed(cycles & TIMER_VALUE_LO_MASK, >> + timer->base + TIMER_LOAD_LO); >> + writel_relaxed(0, timer->base + TIMER_LOAD_HI); >> +} >> + >> +static void sprd_timer_enable_interrupt(struct sprd_timer_device *timer) >> +{ >> + writel_relaxed(TIMER_INT_EN, timer->base + TIMER_INT); >> +} >> + >> +static void sprd_timer_clear_interrupt(struct sprd_timer_device *timer) >> +{ >> + u32 val = readl_relaxed(timer->base + TIMER_INT); >> + >> + val |= TIMER_INT_CLR; >> + writel_relaxed(val, timer->base + TIMER_INT); >> +} >> + >> +static int sprd_timer_set_next_event(unsigned long cycles, >> + struct clock_event_device *ce) >> +{ >> + struct sprd_timer_device *timer = to_sprd_timer(ce); >> + >> + sprd_timer_disable(timer); >> + sprd_timer_update_counter(timer, cycles); >> + sprd_timer_enable(timer, 0); >> + >> + return 0; >> +} >> + >> +static int sprd_timer_set_periodic(struct clock_event_device *ce) >> +{ >> + struct sprd_timer_device *timer = to_sprd_timer(ce); >> + unsigned long cycles = DIV_ROUND_UP(timer->freq, HZ); >> + >> + sprd_timer_disable(timer); >> + sprd_timer_update_counter(timer, cycles); >> + sprd_timer_enable(timer, TIMER_CTL_PERIOD_MODE); >> + >> + return 0; >> +} >> + >> +static int sprd_timer_shutdown(struct clock_event_device *ce) >> +{ >> + struct sprd_timer_device *timer = to_sprd_timer(ce); >> + >> + sprd_timer_disable(timer); >> + return 0; >> +} >> + >> +static irqreturn_t sprd_timer_interrupt(int irq, void *dev_id) >> +{ >> + struct sprd_timer_device *timer = dev_id; >> + >> + sprd_timer_clear_interrupt(timer); >> + >> + if (clockevent_state_oneshot(&timer->ce)) >> + sprd_timer_disable(timer); >> + >> + timer->ce.event_handler(&timer->ce); >> + return IRQ_HANDLED; >> +} >> + >> +static void __init sprd_timer_clkevt_init(struct sprd_timer_device *timer) >> +{ >> + timer->ce.features = CLOCK_EVT_FEAT_DYNIRQ | CLOCK_EVT_FEAT_PERIODIC | >> + CLOCK_EVT_FEAT_ONESHOT; >> + timer->ce.set_next_event = sprd_timer_set_next_event; >> + timer->ce.set_state_periodic = sprd_timer_set_periodic; >> + timer->ce.set_state_shutdown = sprd_timer_shutdown; >> + timer->ce.name = TIMER_NAME; >> + timer->ce.rating = 300; >> + timer->ce.irq = timer->irq; >> + timer->ce.cpumask = cpu_possible_mask; >> + >> + sprd_timer_enable_interrupt(timer); >> + clockevents_config_and_register(&timer->ce, timer->freq, 1, UINT_MAX); >> +} >> + >> +static int __init sprd_timer_init(struct device_node *np) >> +{ >> + struct sprd_timer_device *timer; >> + int ret; >> + >> + timer = kzalloc(sizeof(*timer), GFP_KERNEL); >> + if (!timer) >> + return -ENOMEM; >> + >> + ret = of_property_read_u32(np, "clock-frequency", &timer->freq); >> + if (ret) { >> + pr_err("failed to get clock frequency\n"); >> + goto err_freq; >> + } >> + >> + timer->base = of_iomap(np, 0); >> + if (!timer->base) { >> + pr_err("%s: unable to map resource\n", np->name); >> + ret = -ENXIO; >> + goto err_freq; >> + } >> + >> + timer->irq = irq_of_parse_and_map(np, 0); >> + if (timer->irq < 0) { >> + pr_crit("%s: unable to parse timer irq\n", np->name); >> + ret = timer->irq; >> + goto err_map_irq; >> + } >> + >> + ret = request_irq(timer->irq, sprd_timer_interrupt, IRQF_TIMER, >> + TIMER_NAME, timer); >> + if (ret) { >> + pr_err("failed to setup irq %d\n", timer->irq); >> + goto err_request_irq; >> + } >> + sprd_timer_clkevt_init(timer); > > Please use the timer-of API, that will save you all these operations and > checks. > > One example at: > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/clocksource/sun4i_timer.c#n143 > > And then use the function: > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/clocksource/sun4i_timer.c#n174 > I missed timer-of APIs, and I will check it and use timer-of APIs. Really appreciated for your useful comments. -- Baolin.wang Best Regards -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
