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. > Signed-off-by: Baolin Wang <baolin.w...@spreadtrum.com> > --- > 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. > 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 > + 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. 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). > +#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 ? > +#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). > +#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 -- <http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs Follow Linaro: <http://www.facebook.com/pages/Linaro> Facebook | <http://twitter.com/#!/linaroorg> Twitter | <http://www.linaro.org/linaro-blog/> Blog
