From: Daniel Lezcano Date: Mon, 4 Aug 2025 15:23:21 +0000 (+0200) Subject: clocksource/drivers/vf-pit: Set the scene for multiple timers X-Git-Tag: v6.18-rc1~177^2^2~32 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=3996232e6e7e34a1f783c778f6c7075293912365;p=thirdparty%2Flinux.git clocksource/drivers/vf-pit: Set the scene for multiple timers The driver is implemented as using a single timer and a single clocksource. In order to take advantage of the multiple timers supported in the PIT hardware and introduce different setup for a new platform, let's encapsulate the data into a structure and pass this structure around in the function parameter. The structure will be a per timer instansiation in the next changes. Signed-off-by: Daniel Lezcano Link: https://lore.kernel.org/r/20250804152344.1109310-4-daniel.lezcano@linaro.org --- diff --git a/drivers/clocksource/timer-vf-pit.c b/drivers/clocksource/timer-vf-pit.c index 8041a8f62d1fa..e4a8b32fff756 100644 --- a/drivers/clocksource/timer-vf-pit.c +++ b/drivers/clocksource/timer-vf-pit.c @@ -15,7 +15,7 @@ */ #define PITMCR 0x00 #define PIT0_OFFSET 0x100 -#define PITn_OFFSET(n) (PIT0_OFFSET + 0x10 * (n)) +#define PIT_CH(n) (PIT0_OFFSET + 0x10 * (n)) #define PITLDVAL 0x00 #define PITCVAL 0x04 #define PITTCTRL 0x08 @@ -29,23 +29,36 @@ #define PITTFLG_TIF 0x1 +struct pit_timer { + void __iomem *clksrc_base; + void __iomem *clkevt_base; + unsigned long cycle_per_jiffy; + struct clock_event_device ced; + struct clocksource cs; +}; + +static struct pit_timer pit_timer; + static void __iomem *clksrc_base; -static void __iomem *clkevt_base; -static unsigned long cycle_per_jiffy; -static inline void pit_timer_enable(void) +static inline struct pit_timer *ced_to_pit(struct clock_event_device *ced) { - writel(PITTCTRL_TEN | PITTCTRL_TIE, clkevt_base + PITTCTRL); + return container_of(ced, struct pit_timer, ced); } -static inline void pit_timer_disable(void) +static inline void pit_timer_enable(struct pit_timer *pit) { - writel(0, clkevt_base + PITTCTRL); + writel(PITTCTRL_TEN | PITTCTRL_TIE, pit->clkevt_base + PITTCTRL); } -static inline void pit_irq_acknowledge(void) +static inline void pit_timer_disable(struct pit_timer *pit) { - writel(PITTFLG_TIF, clkevt_base + PITTFLG); + writel(0, pit->clkevt_base + PITTCTRL); +} + +static inline void pit_irq_acknowledge(struct pit_timer *pit) +{ + writel(PITTFLG_TIF, pit->clkevt_base + PITTFLG); } static u64 notrace pit_read_sched_clock(void) @@ -53,21 +66,24 @@ static u64 notrace pit_read_sched_clock(void) return ~readl(clksrc_base + PITCVAL); } -static int __init pit_clocksource_init(unsigned long rate) +static int __init pit_clocksource_init(struct pit_timer *pit, unsigned long rate) { /* set the max load value and start the clock source counter */ - writel(0, clksrc_base + PITTCTRL); - writel(~0UL, clksrc_base + PITLDVAL); - writel(PITTCTRL_TEN, clksrc_base + PITTCTRL); + writel(0, pit->clksrc_base + PITTCTRL); + writel(~0, pit->clksrc_base + PITLDVAL); + writel(PITTCTRL_TEN, pit->clksrc_base + PITTCTRL); + + clksrc_base = pit->clksrc_base; sched_clock_register(pit_read_sched_clock, 32, rate); - return clocksource_mmio_init(clksrc_base + PITCVAL, "vf-pit", rate, + return clocksource_mmio_init(pit->clksrc_base + PITCVAL, "vf-pit", rate, 300, 32, clocksource_mmio_readl_down); } -static int pit_set_next_event(unsigned long delta, - struct clock_event_device *unused) +static int pit_set_next_event(unsigned long delta, struct clock_event_device *ced) { + struct pit_timer *pit = ced_to_pit(ced); + /* * set a new value to PITLDVAL register will not restart the timer, * to abort the current cycle and start a timer period with the new @@ -75,30 +91,37 @@ static int pit_set_next_event(unsigned long delta, * and the PITLAVAL should be set to delta minus one according to pit * hardware requirement. */ - pit_timer_disable(); - writel(delta - 1, clkevt_base + PITLDVAL); - pit_timer_enable(); + pit_timer_disable(pit); + writel(delta - 1, pit->clkevt_base + PITLDVAL); + pit_timer_enable(pit); return 0; } -static int pit_shutdown(struct clock_event_device *evt) +static int pit_shutdown(struct clock_event_device *ced) { - pit_timer_disable(); + struct pit_timer *pit = ced_to_pit(ced); + + pit_timer_disable(pit); + return 0; } -static int pit_set_periodic(struct clock_event_device *evt) +static int pit_set_periodic(struct clock_event_device *ced) { - pit_set_next_event(cycle_per_jiffy, evt); + struct pit_timer *pit = ced_to_pit(ced); + + pit_set_next_event(pit->cycle_per_jiffy, ced); + return 0; } static irqreturn_t pit_timer_interrupt(int irq, void *dev_id) { - struct clock_event_device *evt = dev_id; + struct clock_event_device *ced = dev_id; + struct pit_timer *pit = ced_to_pit(ced); - pit_irq_acknowledge(); + pit_irq_acknowledge(pit); /* * pit hardware doesn't support oneshot, it will generate an interrupt @@ -106,33 +129,33 @@ static irqreturn_t pit_timer_interrupt(int irq, void *dev_id) * and start the counter again. So software need to disable the timer * to stop the counter loop in ONESHOT mode. */ - if (likely(clockevent_state_oneshot(evt))) - pit_timer_disable(); + if (likely(clockevent_state_oneshot(ced))) + pit_timer_disable(pit); - evt->event_handler(evt); + ced->event_handler(ced); return IRQ_HANDLED; } -static struct clock_event_device clockevent_pit = { - .name = "VF pit timer", - .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT, - .set_state_shutdown = pit_shutdown, - .set_state_periodic = pit_set_periodic, - .set_next_event = pit_set_next_event, - .rating = 300, -}; - -static int __init pit_clockevent_init(unsigned long rate, int irq) +static int __init pit_clockevent_init(struct pit_timer *pit, unsigned long rate, int irq) { - writel(0, clkevt_base + PITTCTRL); - writel(PITTFLG_TIF, clkevt_base + PITTFLG); + writel(0, pit->clkevt_base + PITTCTRL); + + writel(PITTFLG_TIF, pit->clkevt_base + PITTFLG); BUG_ON(request_irq(irq, pit_timer_interrupt, IRQF_TIMER | IRQF_IRQPOLL, - "VF pit timer", &clockevent_pit)); + "VF pit timer", &pit->ced)); + + pit->ced.cpumask = cpumask_of(0); + pit->ced.irq = irq; + + pit->ced.name = "VF pit timer"; + pit->ced.features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT; + pit->ced.set_state_shutdown = pit_shutdown; + pit->ced.set_state_periodic = pit_set_periodic; + pit->ced.set_next_event = pit_set_next_event; + pit->ced.rating = 300; - clockevent_pit.cpumask = cpumask_of(0); - clockevent_pit.irq = irq; /* * The value for the LDVAL register trigger is calculated as: * LDVAL trigger = (period / clock period) - 1 @@ -141,7 +164,7 @@ static int __init pit_clockevent_init(unsigned long rate, int irq) * LDVAL trigger value is 1. And then the min_delta is * minimal LDVAL trigger value + 1, and the max_delta is full 32-bit. */ - clockevents_config_and_register(&clockevent_pit, rate, 2, 0xffffffff); + clockevents_config_and_register(&pit->ced, rate, 2, 0xffffffff); return 0; } @@ -164,8 +187,8 @@ static int __init pit_timer_init(struct device_node *np) * so choose PIT2 as clocksource, PIT3 as clockevent device, * and leave PIT0 and PIT1 unused for anyone else who needs them. */ - clksrc_base = timer_base + PITn_OFFSET(2); - clkevt_base = timer_base + PITn_OFFSET(3); + pit_timer.clksrc_base = timer_base + PIT_CH(2); + pit_timer.clkevt_base = timer_base + PIT_CH(3); irq = irq_of_parse_and_map(np, 0); if (irq <= 0) @@ -180,15 +203,15 @@ static int __init pit_timer_init(struct device_node *np) return ret; clk_rate = clk_get_rate(pit_clk); - cycle_per_jiffy = clk_rate / (HZ); + pit_timer.cycle_per_jiffy = clk_rate / (HZ); /* enable the pit module */ writel(~PITMCR_MDIS, timer_base + PITMCR); - ret = pit_clocksource_init(clk_rate); + ret = pit_clocksource_init(&pit_timer, clk_rate); if (ret) return ret; - return pit_clockevent_init(clk_rate, irq); + return pit_clockevent_init(&pit_timer, clk_rate, irq); } TIMER_OF_DECLARE(vf610, "fsl,vf610-pit", pit_timer_init);