[PATCH v7 4/6] clocksource/drivers/exynos_mct: Refactor driver init
From: Will McVicker <hidden>
Date: 2025-12-05 01:10:41
Also in:
linux-samsung-soc, lkml
Subsystem:
clocksource, clockevent drivers, the rest · Maintainers:
Daniel Lezcano, Thomas Gleixner, Linus Torvalds
This patch cleans up the driver a bit by - refactoring mct_init_dt() to allow better separation of ARM 32-bit specific code and ARM64 code. Ultimately this allows the driver to access context data outside of mct_init_dt(). - adds driver data to distinguish the interrupt type which allows a single driver init function. This clean up is in preparation for modularizing the MCT driver for only ARM64 SoCs. Signed-off-by: Will McVicker <redacted> --- drivers/clocksource/exynos_mct.c | 199 +++++++++++++++++++------------ 1 file changed, 125 insertions(+), 74 deletions(-)
diff --git a/drivers/clocksource/exynos_mct.c b/drivers/clocksource/exynos_mct.c
index fece6bbc190e..922c2b519a39 100644
--- a/drivers/clocksource/exynos_mct.c
+++ b/drivers/clocksource/exynos_mct.c@@ -74,13 +74,22 @@ enum { MCT_INT_PPI }; +/* Needs to be global for sched_clock_register() since we can't pass in data. */ static void __iomem *reg_base; -static unsigned long clk_rate; -static unsigned int mct_int_type; -static int mct_irqs[MCT_NR_IRQS]; + +struct mct_data { + unsigned int int_type; +}; + +struct mct_context { + const struct mct_data *drvdata; + unsigned long clk_rate; + int mct_irqs[MCT_NR_IRQS]; +}; struct mct_clock_event_device { struct clock_event_device evt; + struct mct_context *ctx; unsigned long base; /** * The length of the name must be adjusted if number of
@@ -89,6 +98,12 @@ struct mct_clock_event_device { char name[11]; }; +static struct mct_clock_event_device * +to_mct_clock_event_device(struct clock_event_device *evt) +{ + return container_of(evt, struct mct_clock_event_device, evt); +} + static void exynos4_mct_write(unsigned int value, unsigned long offset) { unsigned long stat_addr;
@@ -241,7 +256,7 @@ static cycles_t exynos4_read_current_timer(void) } #endif -static int __init exynos4_clocksource_init(bool frc_shared) +static int __init exynos4_clocksource_init(struct mct_context *ctx, bool frc_shared) { /* * When the frc is shared, the main processor should have already
@@ -252,18 +267,9 @@ static int __init exynos4_clocksource_init(bool frc_shared) else exynos4_mct_frc_start(); -#if defined(CONFIG_ARM) - exynos4_delay_timer.read_current_timer = &exynos4_read_current_timer; - exynos4_delay_timer.freq = clk_rate; - register_current_timer_delay(&exynos4_delay_timer); - - sched_clock_register(exynos4_read_sched_clock, 32, clk_rate); -#endif - - if (clocksource_register_hz(&mct_frc, clk_rate)) + if (clocksource_register_hz(&mct_frc, ctx->clk_rate)) panic("%s: can't register clocksource\n", mct_frc.name); - return 0; }
@@ -297,7 +303,7 @@ static void exynos4_mct_comp0_start(bool periodic, unsigned long cycles) exynos4_mct_write(0x1, EXYNOS4_MCT_G_INT_ENB); tcon |= MCT_G_TCON_COMP0_ENABLE; - exynos4_mct_write(tcon , EXYNOS4_MCT_G_TCON); + exynos4_mct_write(tcon, EXYNOS4_MCT_G_TCON); } static int exynos4_comp_set_next_event(unsigned long cycles,
@@ -325,17 +331,19 @@ static int mct_set_state_periodic(struct clock_event_device *evt) return 0; } -static struct clock_event_device mct_comp_device = { - .name = "mct-comp", - .features = CLOCK_EVT_FEAT_PERIODIC | - CLOCK_EVT_FEAT_ONESHOT, - .rating = 250, - .set_next_event = exynos4_comp_set_next_event, - .set_state_periodic = mct_set_state_periodic, - .set_state_shutdown = mct_set_state_shutdown, - .set_state_oneshot = mct_set_state_shutdown, - .set_state_oneshot_stopped = mct_set_state_shutdown, - .tick_resume = mct_set_state_shutdown, +static struct mct_clock_event_device mct_comp_device = { + .evt = { + .name = "mct-comp", + .features = CLOCK_EVT_FEAT_PERIODIC | + CLOCK_EVT_FEAT_ONESHOT, + .rating = 250, + .set_next_event = exynos4_comp_set_next_event, + .set_state_periodic = mct_set_state_periodic, + .set_state_shutdown = mct_set_state_shutdown, + .set_state_oneshot = mct_set_state_shutdown, + .set_state_oneshot_stopped = mct_set_state_shutdown, + .tick_resume = mct_set_state_shutdown, + }, }; static irqreturn_t exynos4_mct_comp_isr(int irq, void *dev_id)
@@ -349,14 +357,16 @@ static irqreturn_t exynos4_mct_comp_isr(int irq, void *dev_id) return IRQ_HANDLED; } -static int exynos4_clockevent_init(void) +static int exynos4_clockevent_init(struct mct_context *ctx) { - mct_comp_device.cpumask = cpumask_of(0); - clockevents_config_and_register(&mct_comp_device, clk_rate, + struct clock_event_device *evt = &mct_comp_device.evt; + + mct_comp_device.ctx = ctx; + evt->cpumask = cpumask_of(0); + clockevents_config_and_register(evt, ctx->clk_rate, 0xf, 0xffffffff); - if (request_irq(mct_irqs[MCT_G0_IRQ], exynos4_mct_comp_isr, - IRQF_TIMER | IRQF_IRQPOLL, "mct_comp_irq", - &mct_comp_device)) + if (request_irq(ctx->mct_irqs[MCT_G0_IRQ], exynos4_mct_comp_isr, + IRQF_TIMER | IRQF_IRQPOLL, "mct_comp_irq", evt)) pr_err("%s: request_irq() failed\n", "mct_comp_irq"); return 0;
@@ -409,18 +419,16 @@ static void exynos4_mct_tick_clear(struct mct_clock_event_device *mevt) static int exynos4_tick_set_next_event(unsigned long cycles, struct clock_event_device *evt) { - struct mct_clock_event_device *mevt; + struct mct_clock_event_device *mevt = to_mct_clock_event_device(evt); - mevt = container_of(evt, struct mct_clock_event_device, evt); exynos4_mct_tick_start(cycles, mevt); return 0; } static int set_state_shutdown(struct clock_event_device *evt) { - struct mct_clock_event_device *mevt; + struct mct_clock_event_device *mevt = to_mct_clock_event_device(evt); - mevt = container_of(evt, struct mct_clock_event_device, evt); exynos4_mct_tick_stop(mevt); exynos4_mct_tick_clear(mevt); return 0;
@@ -428,10 +436,9 @@ static int set_state_shutdown(struct clock_event_device *evt) static int set_state_periodic(struct clock_event_device *evt) { - struct mct_clock_event_device *mevt; + struct mct_clock_event_device *mevt = to_mct_clock_event_device(evt); unsigned long cycles_per_jiffy; - mevt = container_of(evt, struct mct_clock_event_device, evt); cycles_per_jiffy = (((unsigned long long)NSEC_PER_SEC / HZ * evt->mult) >> evt->shift); exynos4_mct_tick_stop(mevt);
@@ -464,6 +471,7 @@ static int exynos4_mct_starting_cpu(unsigned int cpu) struct mct_clock_event_device *mevt = per_cpu_ptr(&percpu_mct_tick, cpu); struct clock_event_device *evt = &mevt->evt; + struct mct_context *ctx = mevt->ctx; evt->name = mevt->name; evt->cpumask = cpumask_of(cpu);
@@ -479,7 +487,7 @@ static int exynos4_mct_starting_cpu(unsigned int cpu) exynos4_mct_write(TICK_BASE_CNT, mevt->base + MCT_L_TCNTB_OFFSET); - if (mct_int_type == MCT_INT_SPI) { + if (ctx->drvdata->int_type == MCT_INT_SPI) { if (evt->irq == -1) return -EIO;
@@ -487,9 +495,9 @@ static int exynos4_mct_starting_cpu(unsigned int cpu) irq_force_affinity(evt->irq, cpumask_of(cpu)); enable_irq(evt->irq); } else { - enable_percpu_irq(mct_irqs[MCT_L0_IRQ], 0); + enable_percpu_irq(ctx->mct_irqs[MCT_L0_IRQ], 0); } - clockevents_config_and_register(evt, clk_rate / (TICK_BASE_CNT + 1), + clockevents_config_and_register(evt, ctx->clk_rate / (TICK_BASE_CNT + 1), 0xf, 0x7fffffff); return 0;
@@ -500,18 +508,20 @@ static int exynos4_mct_dying_cpu(unsigned int cpu) struct mct_clock_event_device *mevt = per_cpu_ptr(&percpu_mct_tick, cpu); struct clock_event_device *evt = &mevt->evt; + struct mct_context *ctx = mevt->ctx; - if (mct_int_type == MCT_INT_SPI) { + if (ctx->drvdata->int_type == MCT_INT_SPI) { if (evt->irq != -1) disable_irq_nosync(evt->irq); exynos4_mct_write(0x1, mevt->base + MCT_L_INT_CSTAT_OFFSET); } else { - disable_percpu_irq(mct_irqs[MCT_L0_IRQ]); + disable_percpu_irq(ctx->mct_irqs[MCT_L0_IRQ]); } return 0; } -static int __init exynos4_timer_resources(struct device_node *np) +static int __init exynos4_timer_resources(struct mct_context *ctx, + struct device_node *np) { struct clk *mct_clk, *tick_clk;
@@ -522,7 +532,7 @@ static int __init exynos4_timer_resources(struct device_node *np) tick_clk = of_clk_get_by_name(np, "fin_pll"); if (IS_ERR(tick_clk)) panic("%s: unable to determine tick clock rate\n", __func__); - clk_rate = clk_get_rate(tick_clk); + ctx->clk_rate = clk_get_rate(tick_clk); mct_clk = of_clk_get_by_name(np, "mct"); if (IS_ERR(mct_clk))
@@ -534,22 +544,20 @@ static int __init exynos4_timer_resources(struct device_node *np) /** * exynos4_timer_interrupts - initialize MCT interrupts + * @ctx: device context * @np: device node for MCT - * @int_type: interrupt type, MCT_INT_PPI or MCT_INT_SPI * @local_idx: array mapping CPU numbers to local timer indices * @nr_local: size of @local_idx array */ -static int __init exynos4_timer_interrupts(struct device_node *np, - unsigned int int_type, +static int __init exynos4_timer_interrupts(struct mct_context *ctx, + struct device_node *np, const u32 *local_idx, size_t nr_local) { int nr_irqs, i, err, cpu; - mct_int_type = int_type; - /* This driver uses only one global timer interrupt */ - mct_irqs[MCT_G0_IRQ] = irq_of_parse_and_map(np, MCT_G0_IRQ); + ctx->mct_irqs[MCT_G0_IRQ] = irq_of_parse_and_map(np, MCT_G0_IRQ); /* * Find out the number of local irqs specified. The local
@@ -557,29 +565,30 @@ static int __init exynos4_timer_interrupts(struct device_node *np, * irqs are specified. */ nr_irqs = of_irq_count(np); - if (nr_irqs > ARRAY_SIZE(mct_irqs)) { + if (nr_irqs > ARRAY_SIZE(ctx->mct_irqs)) { pr_err("exynos-mct: too many (%d) interrupts configured in DT\n", nr_irqs); - nr_irqs = ARRAY_SIZE(mct_irqs); + nr_irqs = ARRAY_SIZE(ctx->mct_irqs); } for (i = MCT_L0_IRQ; i < nr_irqs; i++) - mct_irqs[i] = irq_of_parse_and_map(np, i); + ctx->mct_irqs[i] = irq_of_parse_and_map(np, i); for_each_possible_cpu(cpu) { struct mct_clock_event_device *mevt = per_cpu_ptr(&percpu_mct_tick, cpu); + mevt->ctx = ctx; snprintf(mevt->name, sizeof(mevt->name), "mct_tick%d", cpu); } - if (mct_int_type == MCT_INT_PPI) { + if (ctx->drvdata->int_type == MCT_INT_PPI) { - err = request_percpu_irq(mct_irqs[MCT_L0_IRQ], + err = request_percpu_irq(ctx->mct_irqs[MCT_L0_IRQ], exynos4_mct_tick_isr, "MCT", &percpu_mct_tick); WARN(err, "MCT: can't request IRQ %d (%d)\n", - mct_irqs[MCT_L0_IRQ], err); + ctx->mct_irqs[MCT_L0_IRQ], err); } else { for_each_possible_cpu(cpu) { int mct_irq;
@@ -595,9 +604,9 @@ static int __init exynos4_timer_interrupts(struct device_node *np, irq_idx = MCT_L0_IRQ + local_idx[cpu]; pcpu_mevt->evt.irq = -1; - if (irq_idx >= ARRAY_SIZE(mct_irqs)) + if (irq_idx >= ARRAY_SIZE(ctx->mct_irqs)) break; - mct_irq = mct_irqs[irq_idx]; + mct_irq = ctx->mct_irqs[irq_idx]; irq_set_status_flags(mct_irq, IRQ_NOAUTOEN); if (request_irq(mct_irq,
@@ -637,8 +646,8 @@ static int __init exynos4_timer_interrupts(struct device_node *np, return 0; out_irq: - if (mct_int_type == MCT_INT_PPI) { - free_percpu_irq(mct_irqs[MCT_L0_IRQ], &percpu_mct_tick); + if (ctx->drvdata->int_type == MCT_INT_PPI) { + free_percpu_irq(ctx->mct_irqs[MCT_L0_IRQ], &percpu_mct_tick); } else { for_each_possible_cpu(cpu) { struct mct_clock_event_device *pcpu_mevt =
@@ -653,7 +662,7 @@ static int __init exynos4_timer_interrupts(struct device_node *np, return err; } -static int __init mct_init_dt(struct device_node *np, unsigned int int_type) +static int __init mct_init_dt(struct mct_context *ctx, struct device_node *np) { bool frc_shared = of_property_read_bool(np, "samsung,frc-shared"); u32 local_idx[MCT_NR_LOCAL] = {0};
@@ -679,15 +688,15 @@ static int __init mct_init_dt(struct device_node *np, unsigned int int_type) local_idx[i] = i; } - ret = exynos4_timer_resources(np); + ret = exynos4_timer_resources(ctx, np); if (ret) return ret; - ret = exynos4_timer_interrupts(np, int_type, local_idx, nr_local); + ret = exynos4_timer_interrupts(ctx, np, local_idx, nr_local); if (ret) return ret; - ret = exynos4_clocksource_init(frc_shared); + ret = exynos4_clocksource_init(ctx, frc_shared); if (ret) return ret;
@@ -698,18 +707,60 @@ static int __init mct_init_dt(struct device_node *np, unsigned int int_type) if (frc_shared) return 0; - return exynos4_clockevent_init(); + ret = exynos4_clockevent_init(ctx); + if (ret) + return ret; + + return 0; } +static const struct mct_data exynos4210_mct_data = { .int_type = MCT_INT_SPI, }; +static const struct mct_data exynos4412_mct_data = { .int_type = MCT_INT_PPI, }; -static int __init mct_init_spi(struct device_node *np) -{ - return mct_init_dt(np, MCT_INT_SPI); -} +static const struct of_device_id exynos4_mct_match_table[] = { + { .compatible = "samsung,exynos4210-mct", .data = &exynos4210_mct_data, }, + { .compatible = "samsung,exynos4412-mct", .data = &exynos4412_mct_data, }, + {} +}; -static int __init mct_init_ppi(struct device_node *np) +/* Note, legacy ARM 32-bit systems depend on the MCT as the only clocksource + * which requires this driver to be initialized very early. We need to keep this + * special condition until we can transparently support modular and early init + * timers. + */ +static int __init mct_of_declare_init(struct device_node *np) { - return mct_init_dt(np, MCT_INT_PPI); + struct mct_context *ctx; + const struct of_device_id *match; + int ret; + + match = of_match_node(exynos4_mct_match_table, np); + if (!match || !match->data) + return -ENODEV; + + ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); + if (!ctx) + return -ENOMEM; + + ctx->drvdata = match->data; + + ret = mct_init_dt(ctx, np); + if (ret) + goto out_ctx; + +#if defined(CONFIG_ARM) + sched_clock_register(exynos4_read_sched_clock, 32, ctx->clk_rate); + + exynos4_delay_timer.read_current_timer = &exynos4_read_current_timer; + exynos4_delay_timer.freq = ctx->clk_rate; + register_current_timer_delay(&exynos4_delay_timer); +#endif + + return 0; + +out_ctx: + kfree(ctx); + return ret; } -TIMER_OF_DECLARE(exynos4210, "samsung,exynos4210-mct", mct_init_spi); -TIMER_OF_DECLARE(exynos4412, "samsung,exynos4412-mct", mct_init_ppi); +TIMER_OF_DECLARE(exynos4210, "samsung,exynos4210-mct", mct_of_declare_init); +TIMER_OF_DECLARE(exynos4412, "samsung,exynos4412-mct", mct_of_declare_init);
--
2.52.0.223.gf5cc29aaa4-goog