diff options
Diffstat (limited to 'drivers/clocksource')
| -rw-r--r-- | drivers/clocksource/Kconfig | 9 | ||||
| -rw-r--r-- | drivers/clocksource/Makefile | 1 | ||||
| -rw-r--r-- | drivers/clocksource/arm_arch_timer.c | 54 | ||||
| -rw-r--r-- | drivers/clocksource/hyperv_timer.c | 96 | ||||
| -rw-r--r-- | drivers/clocksource/ingenic-timer.c | 10 | ||||
| -rw-r--r-- | drivers/clocksource/timer-cadence-ttc.c | 19 | ||||
| -rw-r--r-- | drivers/clocksource/timer-imx-gpt.c | 25 | ||||
| -rw-r--r-- | drivers/clocksource/timer-loongson1-pwm.c | 236 |
8 files changed, 364 insertions, 86 deletions
diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig index 526382dc7482..c4d671a5a13d 100644 --- a/drivers/clocksource/Kconfig +++ b/drivers/clocksource/Kconfig @@ -612,6 +612,15 @@ config TIMER_IMX_SYS_CTR Enable this option to use i.MX system counter timer as a clockevent. +config CLKSRC_LOONGSON1_PWM + bool "Clocksource using Loongson1 PWM" + depends on MACH_LOONGSON32 || COMPILE_TEST + select MIPS_EXTERNAL_TIMER + select TIMER_OF + help + Enable this option to use Loongson1 PWM timer as clocksource + instead of the performance counter. + config CLKSRC_ST_LPC bool "Low power clocksource found in the LPC" if COMPILE_TEST select TIMER_OF if OF diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile index f12d3987a960..5d93c9e3fc55 100644 --- a/drivers/clocksource/Makefile +++ b/drivers/clocksource/Makefile @@ -89,3 +89,4 @@ obj-$(CONFIG_MICROCHIP_PIT64B) += timer-microchip-pit64b.o obj-$(CONFIG_MSC313E_TIMER) += timer-msc313e.o obj-$(CONFIG_GOLDFISH_TIMER) += timer-goldfish.o obj-$(CONFIG_GXP_TIMER) += timer-gxp.o +obj-$(CONFIG_CLKSRC_LOONGSON1_PWM) += timer-loongson1-pwm.o diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c index e09d4427f604..e733a2a1927a 100644 --- a/drivers/clocksource/arm_arch_timer.c +++ b/drivers/clocksource/arm_arch_timer.c @@ -191,22 +191,40 @@ u32 arch_timer_reg_read(int access, enum arch_timer_reg reg, return val; } -static notrace u64 arch_counter_get_cntpct_stable(void) +static noinstr u64 raw_counter_get_cntpct_stable(void) { return __arch_counter_get_cntpct_stable(); } -static notrace u64 arch_counter_get_cntpct(void) +static notrace u64 arch_counter_get_cntpct_stable(void) +{ + u64 val; + preempt_disable_notrace(); + val = __arch_counter_get_cntpct_stable(); + preempt_enable_notrace(); + return val; +} + +static noinstr u64 arch_counter_get_cntpct(void) { return __arch_counter_get_cntpct(); } -static notrace u64 arch_counter_get_cntvct_stable(void) +static noinstr u64 raw_counter_get_cntvct_stable(void) { return __arch_counter_get_cntvct_stable(); } -static notrace u64 arch_counter_get_cntvct(void) +static notrace u64 arch_counter_get_cntvct_stable(void) +{ + u64 val; + preempt_disable_notrace(); + val = __arch_counter_get_cntvct_stable(); + preempt_enable_notrace(); + return val; +} + +static noinstr u64 arch_counter_get_cntvct(void) { return __arch_counter_get_cntvct(); } @@ -753,14 +771,14 @@ static int arch_timer_set_next_event_phys(unsigned long evt, return 0; } -static u64 arch_counter_get_cnt_mem(struct arch_timer *t, int offset_lo) +static noinstr u64 arch_counter_get_cnt_mem(struct arch_timer *t, int offset_lo) { u32 cnt_lo, cnt_hi, tmp_hi; do { - cnt_hi = readl_relaxed(t->base + offset_lo + 4); - cnt_lo = readl_relaxed(t->base + offset_lo); - tmp_hi = readl_relaxed(t->base + offset_lo + 4); + cnt_hi = __le32_to_cpu((__le32 __force)__raw_readl(t->base + offset_lo + 4)); + cnt_lo = __le32_to_cpu((__le32 __force)__raw_readl(t->base + offset_lo)); + tmp_hi = __le32_to_cpu((__le32 __force)__raw_readl(t->base + offset_lo + 4)); } while (cnt_hi != tmp_hi); return ((u64) cnt_hi << 32) | cnt_lo; @@ -1060,7 +1078,7 @@ bool arch_timer_evtstrm_available(void) return cpumask_test_cpu(raw_smp_processor_id(), &evtstrm_available); } -static u64 arch_counter_get_cntvct_mem(void) +static noinstr u64 arch_counter_get_cntvct_mem(void) { return arch_counter_get_cnt_mem(arch_timer_mem, CNTVCT_LO); } @@ -1074,6 +1092,7 @@ struct arch_timer_kvm_info *arch_timer_get_kvm_info(void) static void __init arch_counter_register(unsigned type) { + u64 (*scr)(void); u64 start_count; int width; @@ -1083,21 +1102,28 @@ static void __init arch_counter_register(unsigned type) if ((IS_ENABLED(CONFIG_ARM64) && !is_hyp_mode_available()) || arch_timer_uses_ppi == ARCH_TIMER_VIRT_PPI) { - if (arch_timer_counter_has_wa()) + if (arch_timer_counter_has_wa()) { rd = arch_counter_get_cntvct_stable; - else + scr = raw_counter_get_cntvct_stable; + } else { rd = arch_counter_get_cntvct; + scr = arch_counter_get_cntvct; + } } else { - if (arch_timer_counter_has_wa()) + if (arch_timer_counter_has_wa()) { rd = arch_counter_get_cntpct_stable; - else + scr = raw_counter_get_cntpct_stable; + } else { rd = arch_counter_get_cntpct; + scr = arch_counter_get_cntpct; + } } arch_timer_read_counter = rd; clocksource_counter.vdso_clock_mode = vdso_default; } else { arch_timer_read_counter = arch_counter_get_cntvct_mem; + scr = arch_counter_get_cntvct_mem; } width = arch_counter_get_width(); @@ -1113,7 +1139,7 @@ static void __init arch_counter_register(unsigned type) timecounter_init(&arch_timer_kvm_info.timecounter, &cyclecounter, start_count); - sched_clock_register(arch_timer_read_counter, width, arch_timer_rate); + sched_clock_register(scr, width, arch_timer_rate); } static void arch_timer_stop(struct clock_event_device *clk) diff --git a/drivers/clocksource/hyperv_timer.c b/drivers/clocksource/hyperv_timer.c index bcd9042a0c9f..e56307a81f4d 100644 --- a/drivers/clocksource/hyperv_timer.c +++ b/drivers/clocksource/hyperv_timer.c @@ -365,6 +365,20 @@ void hv_stimer_global_cleanup(void) } EXPORT_SYMBOL_GPL(hv_stimer_global_cleanup); +static __always_inline u64 read_hv_clock_msr(void) +{ + /* + * Read the partition counter to get the current tick count. This count + * is set to 0 when the partition is created and is incremented in 100 + * nanosecond units. + * + * Use hv_raw_get_register() because this function is used from + * noinstr. Notable; while HV_REGISTER_TIME_REF_COUNT is a synthetic + * register it doesn't need the GHCB path. + */ + return hv_raw_get_register(HV_REGISTER_TIME_REF_COUNT); +} + /* * Code and definitions for the Hyper-V clocksources. Two * clocksources are defined: one that reads the Hyper-V defined MSR, and @@ -393,14 +407,20 @@ struct ms_hyperv_tsc_page *hv_get_tsc_page(void) } EXPORT_SYMBOL_GPL(hv_get_tsc_page); -static u64 notrace read_hv_clock_tsc(void) +static __always_inline u64 read_hv_clock_tsc(void) { - u64 current_tick = hv_read_tsc_page(hv_get_tsc_page()); + u64 cur_tsc, time; - if (current_tick == U64_MAX) - current_tick = hv_get_register(HV_REGISTER_TIME_REF_COUNT); + /* + * The Hyper-V Top-Level Function Spec (TLFS), section Timers, + * subsection Refererence Counter, guarantees that the TSC and MSR + * times are in sync and monotonic. Therefore we can fall back + * to the MSR in case the TSC page indicates unavailability. + */ + if (!hv_read_tsc_page_tsc(tsc_page, &cur_tsc, &time)) + time = read_hv_clock_msr(); - return current_tick; + return time; } static u64 notrace read_hv_clock_tsc_cs(struct clocksource *arg) @@ -408,7 +428,7 @@ static u64 notrace read_hv_clock_tsc_cs(struct clocksource *arg) return read_hv_clock_tsc(); } -static u64 notrace read_hv_sched_clock_tsc(void) +static u64 noinstr read_hv_sched_clock_tsc(void) { return (read_hv_clock_tsc() - hv_sched_clock_offset) * (NSEC_PER_SEC / HV_CLOCK_HZ); @@ -460,30 +480,14 @@ static struct clocksource hyperv_cs_tsc = { #endif }; -static u64 notrace read_hv_clock_msr(void) -{ - /* - * Read the partition counter to get the current tick count. This count - * is set to 0 when the partition is created and is incremented in - * 100 nanosecond units. - */ - return hv_get_register(HV_REGISTER_TIME_REF_COUNT); -} - static u64 notrace read_hv_clock_msr_cs(struct clocksource *arg) { return read_hv_clock_msr(); } -static u64 notrace read_hv_sched_clock_msr(void) -{ - return (read_hv_clock_msr() - hv_sched_clock_offset) * - (NSEC_PER_SEC / HV_CLOCK_HZ); -} - static struct clocksource hyperv_cs_msr = { .name = "hyperv_clocksource_msr", - .rating = 500, + .rating = 495, .read = read_hv_clock_msr_cs, .mask = CLOCKSOURCE_MASK(64), .flags = CLOCK_SOURCE_IS_CONTINUOUS, @@ -513,7 +517,7 @@ static __always_inline void hv_setup_sched_clock(void *sched_clock) static __always_inline void hv_setup_sched_clock(void *sched_clock) {} #endif /* CONFIG_GENERIC_SCHED_CLOCK */ -static bool __init hv_init_tsc_clocksource(void) +static void __init hv_init_tsc_clocksource(void) { union hv_reference_tsc_msr tsc_msr; @@ -524,17 +528,14 @@ static bool __init hv_init_tsc_clocksource(void) * Hyper-V Reference TSC rating, causing the generic TSC to be used. * TSC_INVARIANT is not offered on ARM64, so the Hyper-V Reference * TSC will be preferred over the virtualized ARM64 arch counter. - * While the Hyper-V MSR clocksource won't be used since the - * Reference TSC clocksource is present, change its rating as - * well for consistency. */ if (ms_hyperv.features & HV_ACCESS_TSC_INVARIANT) { hyperv_cs_tsc.rating = 250; - hyperv_cs_msr.rating = 250; + hyperv_cs_msr.rating = 245; } if (!(ms_hyperv.features & HV_MSR_REFERENCE_TSC_AVAILABLE)) - return false; + return; hv_read_reference_counter = read_hv_clock_tsc; @@ -565,33 +566,34 @@ static bool __init hv_init_tsc_clocksource(void) clocksource_register_hz(&hyperv_cs_tsc, NSEC_PER_SEC/100); - hv_sched_clock_offset = hv_read_reference_counter(); - hv_setup_sched_clock(read_hv_sched_clock_tsc); - - return true; + /* + * If TSC is invariant, then let it stay as the sched clock since it + * will be faster than reading the TSC page. But if not invariant, use + * the TSC page so that live migrations across hosts with different + * frequencies is handled correctly. + */ + if (!(ms_hyperv.features & HV_ACCESS_TSC_INVARIANT)) { + hv_sched_clock_offset = hv_read_reference_counter(); + hv_setup_sched_clock(read_hv_sched_clock_tsc); + } } void __init hv_init_clocksource(void) { /* - * Try to set up the TSC page clocksource. If it succeeds, we're - * done. Otherwise, set up the MSR clocksource. At least one of - * these will always be available except on very old versions of - * Hyper-V on x86. In that case we won't have a Hyper-V + * Try to set up the TSC page clocksource, then the MSR clocksource. + * At least one of these will always be available except on very old + * versions of Hyper-V on x86. In that case we won't have a Hyper-V * clocksource, but Linux will still run with a clocksource based * on the emulated PIT or LAPIC timer. + * + * Never use the MSR clocksource as sched clock. It's too slow. + * Better to use the native sched clock as the fallback. */ - if (hv_init_tsc_clocksource()) - return; - - if (!(ms_hyperv.features & HV_MSR_TIME_REF_COUNT_AVAILABLE)) - return; - - hv_read_reference_counter = read_hv_clock_msr; - clocksource_register_hz(&hyperv_cs_msr, NSEC_PER_SEC/100); + hv_init_tsc_clocksource(); - hv_sched_clock_offset = hv_read_reference_counter(); - hv_setup_sched_clock(read_hv_sched_clock_msr); + if (ms_hyperv.features & HV_MSR_TIME_REF_COUNT_AVAILABLE) + clocksource_register_hz(&hyperv_cs_msr, NSEC_PER_SEC/100); } void __init hv_remap_tsc_clocksource(void) diff --git a/drivers/clocksource/ingenic-timer.c b/drivers/clocksource/ingenic-timer.c index 089ce64b1c3f..154ee5f7954a 100644 --- a/drivers/clocksource/ingenic-timer.c +++ b/drivers/clocksource/ingenic-timer.c @@ -369,7 +369,7 @@ static int __init ingenic_tcu_probe(struct platform_device *pdev) return 0; } -static int __maybe_unused ingenic_tcu_suspend(struct device *dev) +static int ingenic_tcu_suspend(struct device *dev) { struct ingenic_tcu *tcu = dev_get_drvdata(dev); unsigned int cpu; @@ -382,7 +382,7 @@ static int __maybe_unused ingenic_tcu_suspend(struct device *dev) return 0; } -static int __maybe_unused ingenic_tcu_resume(struct device *dev) +static int ingenic_tcu_resume(struct device *dev) { struct ingenic_tcu *tcu = dev_get_drvdata(dev); unsigned int cpu; @@ -406,7 +406,7 @@ err_timer_clk_disable: return ret; } -static const struct dev_pm_ops __maybe_unused ingenic_tcu_pm_ops = { +static const struct dev_pm_ops ingenic_tcu_pm_ops = { /* _noirq: We want the TCU clocks to be gated last / ungated first */ .suspend_noirq = ingenic_tcu_suspend, .resume_noirq = ingenic_tcu_resume, @@ -415,9 +415,7 @@ static const struct dev_pm_ops __maybe_unused ingenic_tcu_pm_ops = { static struct platform_driver ingenic_tcu_driver = { .driver = { .name = "ingenic-tcu-timer", -#ifdef CONFIG_PM_SLEEP - .pm = &ingenic_tcu_pm_ops, -#endif + .pm = pm_sleep_ptr(&ingenic_tcu_pm_ops), .of_match_table = ingenic_tcu_of_match, }, }; diff --git a/drivers/clocksource/timer-cadence-ttc.c b/drivers/clocksource/timer-cadence-ttc.c index 4efd0cf3b602..0d52e28fea4d 100644 --- a/drivers/clocksource/timer-cadence-ttc.c +++ b/drivers/clocksource/timer-cadence-ttc.c @@ -486,10 +486,10 @@ static int __init ttc_timer_probe(struct platform_device *pdev) * and use it. Note that the event timer uses the interrupt and it's the * 2nd TTC hence the irq_of_parse_and_map(,1) */ - timer_baseaddr = of_iomap(timer, 0); - if (!timer_baseaddr) { + timer_baseaddr = devm_of_iomap(&pdev->dev, timer, 0, NULL); + if (IS_ERR(timer_baseaddr)) { pr_err("ERROR: invalid timer base address\n"); - return -ENXIO; + return PTR_ERR(timer_baseaddr); } irq = irq_of_parse_and_map(timer, 1); @@ -513,20 +513,27 @@ static int __init ttc_timer_probe(struct platform_device *pdev) clk_ce = of_clk_get(timer, clksel); if (IS_ERR(clk_ce)) { pr_err("ERROR: timer input clock not found\n"); - return PTR_ERR(clk_ce); + ret = PTR_ERR(clk_ce); + goto put_clk_cs; } ret = ttc_setup_clocksource(clk_cs, timer_baseaddr, timer_width); if (ret) - return ret; + goto put_clk_ce; ret = ttc_setup_clockevent(clk_ce, timer_baseaddr + 4, irq); if (ret) - return ret; + goto put_clk_ce; pr_info("%pOFn #0 at %p, irq=%d\n", timer, timer_baseaddr, irq); return 0; + +put_clk_ce: + clk_put(clk_ce); +put_clk_cs: + clk_put(clk_cs); + return ret; } static const struct of_device_id ttc_timer_of_match[] = { diff --git a/drivers/clocksource/timer-imx-gpt.c b/drivers/clocksource/timer-imx-gpt.c index ca3e4cbc80c6..28ab4f1a7c71 100644 --- a/drivers/clocksource/timer-imx-gpt.c +++ b/drivers/clocksource/timer-imx-gpt.c @@ -16,7 +16,6 @@ #include <linux/of.h> #include <linux/of_address.h> #include <linux/of_irq.h> -#include <soc/imx/timer.h> /* * There are 4 versions of the timer hardware on Freescale MXC hardware. @@ -25,6 +24,12 @@ * - MX25, MX31, MX35, MX37, MX51, MX6Q(rev1.0) * - MX6DL, MX6SX, MX6Q(rev1.1+) */ +enum imx_gpt_type { + GPT_TYPE_IMX1, /* i.MX1 */ + GPT_TYPE_IMX21, /* i.MX21/27 */ + GPT_TYPE_IMX31, /* i.MX31/35/25/37/51/6Q */ + GPT_TYPE_IMX6DL, /* i.MX6DL/SX/SL */ +}; /* defines common for all i.MX */ #define MXC_TCTL 0x00 @@ -93,13 +98,11 @@ static void imx1_gpt_irq_disable(struct imx_timer *imxtm) tmp = readl_relaxed(imxtm->base + MXC_TCTL); writel_relaxed(tmp & ~MX1_2_TCTL_IRQEN, imxtm->base + MXC_TCTL); } -#define imx21_gpt_irq_disable imx1_gpt_irq_disable static void imx31_gpt_irq_disable(struct imx_timer *imxtm) { writel_relaxed(0, imxtm->base + V2_IR); } -#define imx6dl_gpt_irq_disable imx31_gpt_irq_disable static void imx1_gpt_irq_enable(struct imx_timer *imxtm) { @@ -108,13 +111,11 @@ static void imx1_gpt_irq_enable(struct imx_timer *imxtm) tmp = readl_relaxed(imxtm->base + MXC_TCTL); writel_relaxed(tmp | MX1_2_TCTL_IRQEN, imxtm->base + MXC_TCTL); } -#define imx21_gpt_irq_enable imx1_gpt_irq_enable static void imx31_gpt_irq_enable(struct imx_timer *imxtm) { writel_relaxed(1<<0, imxtm->base + V2_IR); } -#define imx6dl_gpt_irq_enable imx31_gpt_irq_enable static void imx1_gpt_irq_acknowledge(struct imx_timer *imxtm) { @@ -131,7 +132,6 @@ static void imx31_gpt_irq_acknowledge(struct imx_timer *imxtm) { writel_relaxed(V2_TSTAT_OF1, imxtm->base + V2_TSTAT); } -#define imx6dl_gpt_irq_acknowledge imx31_gpt_irq_acknowledge static void __iomem *sched_clock_reg; @@ -296,7 +296,6 @@ static void imx1_gpt_setup_tctl(struct imx_timer *imxtm) tctl_val = MX1_2_TCTL_FRR | MX1_2_TCTL_CLK_PCLK1 | MXC_TCTL_TEN; writel_relaxed(tctl_val, imxtm->base + MXC_TCTL); } -#define imx21_gpt_setup_tctl imx1_gpt_setup_tctl static void imx31_gpt_setup_tctl(struct imx_timer *imxtm) { @@ -343,10 +342,10 @@ static const struct imx_gpt_data imx21_gpt_data = { .reg_tstat = MX1_2_TSTAT, .reg_tcn = MX1_2_TCN, .reg_tcmp = MX1_2_TCMP, - .gpt_irq_enable = imx21_gpt_irq_enable, - .gpt_irq_disable = imx21_gpt_irq_disable, + .gpt_irq_enable = imx1_gpt_irq_enable, + .gpt_irq_disable = imx1_gpt_irq_disable, .gpt_irq_acknowledge = imx21_gpt_irq_acknowledge, - .gpt_setup_tctl = imx21_gpt_setup_tctl, + .gpt_setup_tctl = imx1_gpt_setup_tctl, .set_next_event = mx1_2_set_next_event, }; @@ -365,9 +364,9 @@ static const struct imx_gpt_data imx6dl_gpt_data = { .reg_tstat = V2_TSTAT, .reg_tcn = V2_TCN, .reg_tcmp = V2_TCMP, - .gpt_irq_enable = imx6dl_gpt_irq_enable, - .gpt_irq_disable = imx6dl_gpt_irq_disable, - .gpt_irq_acknowledge = imx6dl_gpt_irq_acknowledge, + .gpt_irq_enable = imx31_gpt_irq_enable, + .gpt_irq_disable = imx31_gpt_irq_disable, + .gpt_irq_acknowledge = imx31_gpt_irq_acknowledge, .gpt_setup_tctl = imx6dl_gpt_setup_tctl, .set_next_event = v2_set_next_event, }; diff --git a/drivers/clocksource/timer-loongson1-pwm.c b/drivers/clocksource/timer-loongson1-pwm.c new file mode 100644 index 000000000000..6335fee03017 --- /dev/null +++ b/drivers/clocksource/timer-loongson1-pwm.c @@ -0,0 +1,236 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Clocksource driver for Loongson-1 SoC + * + * Copyright (c) 2023 Keguang Zhang <keguang.zhang@gmail.com> + */ + +#include <linux/clockchips.h> +#include <linux/interrupt.h> +#include <linux/sizes.h> +#include "timer-of.h" + +/* Loongson-1 PWM Timer Register Definitions */ +#define PWM_CNTR 0x0 +#define PWM_HRC 0x4 +#define PWM_LRC 0x8 +#define PWM_CTRL 0xc + +/* PWM Control Register Bits */ +#define INT_LRC_EN BIT(11) +#define INT_HRC_EN BIT(10) +#define CNTR_RST BIT(7) +#define INT_SR BIT(6) +#define INT_EN BIT(5) +#define PWM_SINGLE BIT(4) +#define PWM_OE BIT(3) +#define CNT_EN BIT(0) + +#define CNTR_WIDTH 24 + +DEFINE_RAW_SPINLOCK(ls1x_timer_lock); + +struct ls1x_clocksource { + void __iomem *reg_base; + unsigned long ticks_per_jiffy; + struct clocksource clksrc; +}; + +static inline struct ls1x_clocksource *to_ls1x_clksrc(struct clocksource *c) +{ + return container_of(c, struct ls1x_clocksource, clksrc); +} + +static inline void ls1x_pwmtimer_set_period(unsigned int period, + struct timer_of *to) +{ + writel(period, timer_of_base(to) + PWM_LRC); + writel(period, timer_of_base(to) + PWM_HRC); +} + +static inline void ls1x_pwmtimer_clear(struct timer_of *to) +{ + writel(0, timer_of_base(to) + PWM_CNTR); +} + +static inline void ls1x_pwmtimer_start(struct timer_of *to) +{ + writel((INT_EN | PWM_OE | CNT_EN), timer_of_base(to) + PWM_CTRL); +} + +static inline void ls1x_pwmtimer_stop(struct timer_of *to) +{ + writel(0, timer_of_base(to) + PWM_CTRL); +} + +static inline void ls1x_pwmtimer_irq_ack(struct timer_of *to) +{ + int val; + + val = readl(timer_of_base(to) + PWM_CTRL); + val |= INT_SR; + writel(val, timer_of_base(to) + PWM_CTRL); +} + +static irqreturn_t ls1x_clockevent_isr(int irq, void *dev_id) +{ + struct clock_event_device *clkevt = dev_id; + struct timer_of *to = to_timer_of(clkevt); + + ls1x_pwmtimer_irq_ack(to); + ls1x_pwmtimer_clear(to); + ls1x_pwmtimer_start(to); + + clkevt->event_handler(clkevt); + + return IRQ_HANDLED; +} + +static int ls1x_clockevent_set_state_periodic(struct clock_event_device *clkevt) +{ + struct timer_of *to = to_timer_of(clkevt); + + raw_spin_lock(&ls1x_timer_lock); + ls1x_pwmtimer_set_period(timer_of_period(to), to); + ls1x_pwmtimer_clear(to); + ls1x_pwmtimer_start(to); + raw_spin_unlock(&ls1x_timer_lock); + + return 0; +} + +static int ls1x_clockevent_tick_resume(struct clock_event_device *clkevt) +{ + raw_spin_lock(&ls1x_timer_lock); + ls1x_pwmtimer_start(to_timer_of(clkevt)); + raw_spin_unlock(&ls1x_timer_lock); + + return 0; +} + +static int ls1x_clockevent_set_state_shutdown(struct clock_event_device *clkevt) +{ + raw_spin_lock(&ls1x_timer_lock); + ls1x_pwmtimer_stop(to_timer_of(clkevt)); + raw_spin_unlock(&ls1x_timer_lock); + + return 0; +} + +static int ls1x_clockevent_set_next(unsigned long evt, + struct clock_event_device *clkevt) +{ + struct timer_of *to = to_timer_of(clkevt); + + raw_spin_lock(&ls1x_timer_lock); + ls1x_pwmtimer_set_period(evt, to); + ls1x_pwmtimer_clear(to); + ls1x_pwmtimer_start(to); + raw_spin_unlock(&ls1x_timer_lock); + + return 0; +} + +static struct timer_of ls1x_to = { + .flags = TIMER_OF_IRQ | TIMER_OF_BASE | TIMER_OF_CLOCK, + .clkevt = { + .name = "ls1x-pwmtimer", + .features = CLOCK_EVT_FEAT_PERIODIC | + CLOCK_EVT_FEAT_ONESHOT, + .rating = 300, + .set_next_event = ls1x_clockevent_set_next, + .set_state_periodic = ls1x_clockevent_set_state_periodic, + .set_state_oneshot = ls1x_clockevent_set_state_shutdown, + .set_state_shutdown = ls1x_clockevent_set_state_shutdown, + .tick_resume = ls1x_clockevent_tick_resume, + }, + .of_irq = { + .handler = ls1x_clockevent_isr, + .flags = IRQF_TIMER, + }, +}; + +/* + * Since the PWM timer overflows every two ticks, its not very useful + * to just read by itself. So use jiffies to emulate a free + * running counter: + */ +static u64 ls1x_clocksource_read(struct clocksource *cs) +{ + struct ls1x_clocksource *ls1x_cs = to_ls1x_clksrc(cs); + unsigned long flags; + int count; + u32 jifs; + static int old_count; + static u32 old_jifs; + + raw_spin_lock_irqsave(&ls1x_timer_lock, flags); + /* + * Although our caller may have the read side of xtime_lock, + * this is now a seqlock, and we are cheating in this routine + * by having side effects on state that we cannot undo if + * there is a collision on the seqlock and our caller has to + * retry. (Namely, old_jifs and old_count.) So we must treat + * jiffies as volatile despite the lock. We read jiffies + * before latching the timer count to guarantee that although + * the jiffies value might be older than the count (that is, + * the counter may underflow between the last point where + * jiffies was incremented and the point where we latch the + * count), it cannot be newer. + */ + jifs = jiffies; + /* read the count */ + count = readl(ls1x_cs->reg_base + PWM_CNTR); + + /* + * It's possible for count to appear to go the wrong way for this + * reason: + * + * The timer counter underflows, but we haven't handled the resulting + * interrupt and incremented jiffies yet. + * + * Previous attempts to handle these cases intelligently were buggy, so + * we just do the simple thing now. + */ + if (count < old_count && jifs == old_jifs) + count = old_count; + + old_count = count; + old_jifs = jifs; + + raw_spin_unlock_irqrestore(&ls1x_timer_lock, flags); + + return (u64)(jifs * ls1x_cs->ticks_per_jiffy) + count; +} + +static struct ls1x_clocksource ls1x_clocksource = { + .clksrc = { + .name = "ls1x-pwmtimer", + .rating = 300, + .read = ls1x_clocksource_read, + .mask = CLOCKSOURCE_MASK(CNTR_WIDTH), + .flags = CLOCK_SOURCE_IS_CONTINUOUS, + }, +}; + +static int __init ls1x_pwm_clocksource_init(struct device_node *np) +{ + struct timer_of *to = &ls1x_to; + int ret; + + ret = timer_of_init(np, to); + if (ret) + return ret; + + clockevents_config_and_register(&to->clkevt, timer_of_rate(to), + 0x1, GENMASK(CNTR_WIDTH - 1, 0)); + + ls1x_clocksource.reg_base = timer_of_base(to); + ls1x_clocksource.ticks_per_jiffy = timer_of_period(to); + + return clocksource_register_hz(&ls1x_clocksource.clksrc, + timer_of_rate(to)); +} + +TIMER_OF_DECLARE(ls1x_pwm_clocksource, "loongson,ls1b-pwmtimer", + ls1x_pwm_clocksource_init); |