diff --git a/Documentation/devicetree/bindings/arm/armv7m_systick.txt b/Documentation/devicetree/bindings/arm/armv7m_systick.txt new file mode 100644 index 0000000000000000000000000000000000000000..7cf4a24601eb2e2365e2bc4893a5ecd026074187 --- /dev/null +++ b/Documentation/devicetree/bindings/arm/armv7m_systick.txt @@ -0,0 +1,26 @@ +* ARMv7M System Timer + +ARMv7-M includes a system timer, known as SysTick. Current driver only +implements the clocksource feature. + +Required properties: +- compatible : Should be "arm,armv7m-systick" +- reg : The address range of the timer + +Required clocking property, have to be one of: +- clocks : The input clock of the timer +- clock-frequency : The rate in HZ in input of the ARM SysTick + +Examples: + +systick: timer@e000e010 { + compatible = "arm,armv7m-systick"; + reg = <0xe000e010 0x10>; + clocks = <&clk_systick>; +}; + +systick: timer@e000e010 { + compatible = "arm,armv7m-systick"; + reg = <0xe000e010 0x10>; + clock-frequency = <90000000>; +}; diff --git a/Documentation/devicetree/bindings/timer/nxp,lpc3220-timer.txt b/Documentation/devicetree/bindings/timer/nxp,lpc3220-timer.txt new file mode 100644 index 0000000000000000000000000000000000000000..51b05a0e70d19118184f93bf14707cc678793813 --- /dev/null +++ b/Documentation/devicetree/bindings/timer/nxp,lpc3220-timer.txt @@ -0,0 +1,26 @@ +* NXP LPC3220 timer + +The NXP LPC3220 timer is used on a wide range of NXP SoCs. This +includes LPC32xx, LPC178x, LPC18xx and LPC43xx parts. + +Required properties: +- compatible: + Should be "nxp,lpc3220-timer". +- reg: + Address and length of the register set. +- interrupts: + Reference to the timer interrupt +- clocks: + Should contain a reference to timer clock. +- clock-names: + Should contain "timerclk". + +Example: + +timer1: timer@40085000 { + compatible = "nxp,lpc3220-timer"; + reg = <0x40085000 0x1000>; + interrupts = <13>; + clocks = <&ccu1 CLK_CPU_TIMER1>; + clock-names = "timerclk"; +}; diff --git a/Documentation/devicetree/bindings/timer/st,stm32-timer.txt b/Documentation/devicetree/bindings/timer/st,stm32-timer.txt new file mode 100644 index 0000000000000000000000000000000000000000..8ef28e70d6e84ef8f11dff80a34a226d861ff1ab --- /dev/null +++ b/Documentation/devicetree/bindings/timer/st,stm32-timer.txt @@ -0,0 +1,22 @@ +. STMicroelectronics STM32 timer + +The STM32 MCUs family has several general-purpose 16 and 32 bits timers. + +Required properties: +- compatible : Should be "st,stm32-timer" +- reg : Address and length of the register set +- clocks : Reference on the timer input clock +- interrupts : Reference to the timer interrupt + +Optional properties: +- resets: Reference to a reset controller asserting the timer + +Example: + +timer5: timer@40000c00 { + compatible = "st,stm32-timer"; + reg = <0x40000c00 0x400>; + interrupts = <50>; + resets = <&rrc 259>; + clocks = <&clk_pmtr1>; +}; diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig index 51d7865fdddb6d59ae7a9406ae8d88cb4da30066..bec25b39ecf20066b7f82780ec85a6022feeb087 100644 --- a/drivers/clocksource/Kconfig +++ b/drivers/clocksource/Kconfig @@ -106,6 +106,16 @@ config CLKSRC_EFM32 Support to use the timers of EFM32 SoCs as clock source and clock event device. +config CLKSRC_LPC32XX + bool + select CLKSRC_MMIO + select CLKSRC_OF + +config CLKSRC_STM32 + bool "Clocksource for STM32 SoCs" if COMPILE_TEST + depends on OF + select CLKSRC_MMIO + config ARM_ARCH_TIMER bool select CLKSRC_OF if OF @@ -139,6 +149,13 @@ config CLKSRC_ARM_GLOBAL_TIMER_SCHED_CLOCK help Use ARM global timer clock source as sched_clock +config ARMV7M_SYSTICK + bool + select CLKSRC_OF if OF + select CLKSRC_MMIO + help + This options enables support for the ARMv7M system timer unit + config ATMEL_PIT select CLKSRC_OF if OF def_bool SOC_AT91SAM9 || SOC_SAMA5 diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile index 5b85f6adb25834c807c24aafa08ed0529b2e8a53..1831a588b988b508e885687313e189bacffda4a2 100644 --- a/drivers/clocksource/Makefile +++ b/drivers/clocksource/Makefile @@ -36,7 +36,9 @@ obj-$(CONFIG_ARCH_NSPIRE) += zevio-timer.o obj-$(CONFIG_ARCH_BCM_MOBILE) += bcm_kona_timer.o obj-$(CONFIG_CADENCE_TTC_TIMER) += cadence_ttc_timer.o obj-$(CONFIG_CLKSRC_EFM32) += time-efm32.o +obj-$(CONFIG_CLKSRC_STM32) += timer-stm32.o obj-$(CONFIG_CLKSRC_EXYNOS_MCT) += exynos_mct.o +obj-$(CONFIG_CLKSRC_LPC32XX) += time-lpc32xx.o obj-$(CONFIG_CLKSRC_SAMSUNG_PWM) += samsung_pwm_timer.o obj-$(CONFIG_FSL_FTM_TIMER) += fsl_ftm_timer.o obj-$(CONFIG_VF_PIT_TIMER) += vf_pit_timer.o @@ -45,6 +47,7 @@ obj-$(CONFIG_MTK_TIMER) += mtk_timer.o obj-$(CONFIG_ARM_ARCH_TIMER) += arm_arch_timer.o obj-$(CONFIG_ARM_GLOBAL_TIMER) += arm_global_timer.o +obj-$(CONFIG_ARMV7M_SYSTICK) += armv7m_systick.o obj-$(CONFIG_CLKSRC_METAG_GENERIC) += metag_generic.o obj-$(CONFIG_ARCH_HAS_TICK_BROADCAST) += dummy_timer.o obj-$(CONFIG_ARCH_KEYSTONE) += timer-keystone.o diff --git a/drivers/clocksource/armv7m_systick.c b/drivers/clocksource/armv7m_systick.c new file mode 100644 index 0000000000000000000000000000000000000000..addfd2c64f54ef4c75aeb483d0401c1f40a77022 --- /dev/null +++ b/drivers/clocksource/armv7m_systick.c @@ -0,0 +1,79 @@ +/* + * Copyright (C) Maxime Coquelin 2015 + * Author: Maxime Coquelin + * License terms: GNU General Public License (GPL), version 2 + */ + +#include +#include +#include +#include +#include +#include +#include + +#define SYST_CSR 0x00 +#define SYST_RVR 0x04 +#define SYST_CVR 0x08 +#define SYST_CALIB 0x0c + +#define SYST_CSR_ENABLE BIT(0) + +#define SYSTICK_LOAD_RELOAD_MASK 0x00FFFFFF + +static void __init system_timer_of_register(struct device_node *np) +{ + struct clk *clk = NULL; + void __iomem *base; + u32 rate; + int ret; + + base = of_iomap(np, 0); + if (!base) { + pr_warn("system-timer: invalid base address\n"); + return; + } + + ret = of_property_read_u32(np, "clock-frequency", &rate); + if (ret) { + clk = of_clk_get(np, 0); + if (IS_ERR(clk)) + goto out_unmap; + + ret = clk_prepare_enable(clk); + if (ret) + goto out_clk_put; + + rate = clk_get_rate(clk); + if (!rate) + goto out_clk_disable; + } + + writel_relaxed(SYSTICK_LOAD_RELOAD_MASK, base + SYST_RVR); + writel_relaxed(SYST_CSR_ENABLE, base + SYST_CSR); + + ret = clocksource_mmio_init(base + SYST_CVR, "arm_system_timer", rate, + 200, 24, clocksource_mmio_readl_down); + if (ret) { + pr_err("failed to init clocksource (%d)\n", ret); + if (clk) + goto out_clk_disable; + else + goto out_unmap; + } + + pr_info("ARM System timer initialized as clocksource\n"); + + return; + +out_clk_disable: + clk_disable_unprepare(clk); +out_clk_put: + clk_put(clk); +out_unmap: + iounmap(base); + pr_warn("ARM System timer register failed (%d)\n", ret); +} + +CLOCKSOURCE_OF_DECLARE(arm_systick, "arm,armv7m-systick", + system_timer_of_register); diff --git a/drivers/clocksource/exynos_mct.c b/drivers/clocksource/exynos_mct.c index 83564c9cfdbe3b18dfb07a3799b73b991ffe00c7..935b05936dbdd9588764b0c04bf84db32b425af0 100644 --- a/drivers/clocksource/exynos_mct.c +++ b/drivers/clocksource/exynos_mct.c @@ -209,7 +209,7 @@ static void exynos4_frc_resume(struct clocksource *cs) exynos4_mct_frc_start(); } -struct clocksource mct_frc = { +static struct clocksource mct_frc = { .name = "mct-frc", .rating = 400, .read = exynos4_frc_read, @@ -413,7 +413,7 @@ static inline void exynos4_tick_set_mode(enum clock_event_mode mode, } } -static int exynos4_mct_tick_clear(struct mct_clock_event_device *mevt) +static void exynos4_mct_tick_clear(struct mct_clock_event_device *mevt) { struct clock_event_device *evt = &mevt->evt; @@ -426,12 +426,8 @@ static int exynos4_mct_tick_clear(struct mct_clock_event_device *mevt) exynos4_mct_tick_stop(mevt); /* Clear the MCT tick interrupt */ - if (readl_relaxed(reg_base + mevt->base + MCT_L_INT_CSTAT_OFFSET) & 1) { + if (readl_relaxed(reg_base + mevt->base + MCT_L_INT_CSTAT_OFFSET) & 1) exynos4_mct_write(0x1, mevt->base + MCT_L_INT_CSTAT_OFFSET); - return 1; - } else { - return 0; - } } static irqreturn_t exynos4_mct_tick_isr(int irq, void *dev_id) @@ -564,18 +560,6 @@ static void __init exynos4_timer_resources(struct device_node *np, void __iomem free_percpu_irq(mct_irqs[MCT_L0_IRQ], &percpu_mct_tick); } -void __init mct_init(void __iomem *base, int irq_g0, int irq_l0, int irq_l1) -{ - mct_irqs[MCT_G0_IRQ] = irq_g0; - mct_irqs[MCT_L0_IRQ] = irq_l0; - mct_irqs[MCT_L1_IRQ] = irq_l1; - mct_int_type = MCT_INT_SPI; - - exynos4_timer_resources(NULL, base); - exynos4_clocksource_init(); - exynos4_clockevent_init(); -} - static void __init mct_init_dt(struct device_node *np, unsigned int int_type) { u32 nr_irqs, i; diff --git a/drivers/clocksource/qcom-timer.c b/drivers/clocksource/qcom-timer.c index 098c542e5c537dca3f159771960b453d61b578a8..cba2d015564c2cfe9dd9735ef771d7bc355ecca9 100644 --- a/drivers/clocksource/qcom-timer.c +++ b/drivers/clocksource/qcom-timer.c @@ -40,8 +40,6 @@ #define GPT_HZ 32768 -#define MSM_DGT_SHIFT 5 - static void __iomem *event_base; static void __iomem *sts_base; @@ -232,7 +230,6 @@ static void __init msm_timer_init(u32 dgt_hz, int sched_bits, int irq, register_current_timer_delay(&msm_delay_timer); } -#ifdef CONFIG_ARCH_QCOM static void __init msm_dt_timer_init(struct device_node *np) { u32 freq; @@ -285,59 +282,3 @@ static void __init msm_dt_timer_init(struct device_node *np) } CLOCKSOURCE_OF_DECLARE(kpss_timer, "qcom,kpss-timer", msm_dt_timer_init); CLOCKSOURCE_OF_DECLARE(scss_timer, "qcom,scss-timer", msm_dt_timer_init); -#else - -static int __init msm_timer_map(phys_addr_t addr, u32 event, u32 source, - u32 sts) -{ - void __iomem *base; - - base = ioremap(addr, SZ_256); - if (!base) { - pr_err("Failed to map timer base\n"); - return -ENOMEM; - } - event_base = base + event; - source_base = base + source; - if (sts) - sts_base = base + sts; - - return 0; -} - -static notrace cycle_t msm_read_timer_count_shift(struct clocksource *cs) -{ - /* - * Shift timer count down by a constant due to unreliable lower bits - * on some targets. - */ - return msm_read_timer_count(cs) >> MSM_DGT_SHIFT; -} - -void __init msm7x01_timer_init(void) -{ - struct clocksource *cs = &msm_clocksource; - - if (msm_timer_map(0xc0100000, 0x0, 0x10, 0x0)) - return; - cs->read = msm_read_timer_count_shift; - cs->mask = CLOCKSOURCE_MASK((32 - MSM_DGT_SHIFT)); - /* 600 KHz */ - msm_timer_init(19200000 >> MSM_DGT_SHIFT, 32 - MSM_DGT_SHIFT, 7, - false); -} - -void __init msm7x30_timer_init(void) -{ - if (msm_timer_map(0xc0100000, 0x4, 0x24, 0x80)) - return; - msm_timer_init(24576000 / 4, 32, 1, false); -} - -void __init qsd8x50_timer_init(void) -{ - if (msm_timer_map(0xAC100000, 0x0, 0x10, 0x34)) - return; - msm_timer_init(19200000 / 4, 32, 7, false); -} -#endif diff --git a/drivers/clocksource/time-lpc32xx.c b/drivers/clocksource/time-lpc32xx.c new file mode 100644 index 0000000000000000000000000000000000000000..a1c06a2bc77c55160fa8283378877cb8d1062820 --- /dev/null +++ b/drivers/clocksource/time-lpc32xx.c @@ -0,0 +1,272 @@ +/* + * Clocksource driver for NXP LPC32xx/18xx/43xx timer + * + * Copyright (C) 2015 Joachim Eastwood + * + * Based on: + * time-efm32 Copyright (C) 2013 Pengutronix + * mach-lpc32xx/timer.c Copyright (C) 2009 - 2010 NXP Semiconductors + * + * This file is licensed under the terms of the GNU General Public + * License version 2. This program is licensed "as is" without any + * warranty of any kind, whether express or implied. + * + */ + +#define pr_fmt(fmt) "%s: " fmt, __func__ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define LPC32XX_TIMER_IR 0x000 +#define LPC32XX_TIMER_IR_MR0INT BIT(0) +#define LPC32XX_TIMER_TCR 0x004 +#define LPC32XX_TIMER_TCR_CEN BIT(0) +#define LPC32XX_TIMER_TCR_CRST BIT(1) +#define LPC32XX_TIMER_TC 0x008 +#define LPC32XX_TIMER_PR 0x00c +#define LPC32XX_TIMER_MCR 0x014 +#define LPC32XX_TIMER_MCR_MR0I BIT(0) +#define LPC32XX_TIMER_MCR_MR0R BIT(1) +#define LPC32XX_TIMER_MCR_MR0S BIT(2) +#define LPC32XX_TIMER_MR0 0x018 +#define LPC32XX_TIMER_CTCR 0x070 + +struct lpc32xx_clock_event_ddata { + struct clock_event_device evtdev; + void __iomem *base; +}; + +/* Needed for the sched clock */ +static void __iomem *clocksource_timer_counter; + +static u64 notrace lpc32xx_read_sched_clock(void) +{ + return readl(clocksource_timer_counter); +} + +static int lpc32xx_clkevt_next_event(unsigned long delta, + struct clock_event_device *evtdev) +{ + struct lpc32xx_clock_event_ddata *ddata = + container_of(evtdev, struct lpc32xx_clock_event_ddata, evtdev); + + /* + * Place timer in reset and program the delta in the prescale + * register (PR). When the prescale counter matches the value + * in PR the counter register is incremented and the compare + * match will trigger. After setup the timer is released from + * reset and enabled. + */ + writel_relaxed(LPC32XX_TIMER_TCR_CRST, ddata->base + LPC32XX_TIMER_TCR); + writel_relaxed(delta, ddata->base + LPC32XX_TIMER_PR); + writel_relaxed(LPC32XX_TIMER_TCR_CEN, ddata->base + LPC32XX_TIMER_TCR); + + return 0; +} + +static int lpc32xx_clkevt_shutdown(struct clock_event_device *evtdev) +{ + struct lpc32xx_clock_event_ddata *ddata = + container_of(evtdev, struct lpc32xx_clock_event_ddata, evtdev); + + /* Disable the timer */ + writel_relaxed(0, ddata->base + LPC32XX_TIMER_TCR); + + return 0; +} + +static int lpc32xx_clkevt_oneshot(struct clock_event_device *evtdev) +{ + /* + * When using oneshot, we must also disable the timer + * to wait for the first call to set_next_event(). + */ + return lpc32xx_clkevt_shutdown(evtdev); +} + +static irqreturn_t lpc32xx_clock_event_handler(int irq, void *dev_id) +{ + struct lpc32xx_clock_event_ddata *ddata = dev_id; + + /* Clear match on channel 0 */ + writel_relaxed(LPC32XX_TIMER_IR_MR0INT, ddata->base + LPC32XX_TIMER_IR); + + ddata->evtdev.event_handler(&ddata->evtdev); + + return IRQ_HANDLED; +} + +static struct lpc32xx_clock_event_ddata lpc32xx_clk_event_ddata = { + .evtdev = { + .name = "lpc3220 clockevent", + .features = CLOCK_EVT_FEAT_ONESHOT, + .rating = 300, + .set_next_event = lpc32xx_clkevt_next_event, + .set_state_shutdown = lpc32xx_clkevt_shutdown, + .set_state_oneshot = lpc32xx_clkevt_oneshot, + }, +}; + +static int __init lpc32xx_clocksource_init(struct device_node *np) +{ + void __iomem *base; + unsigned long rate; + struct clk *clk; + int ret; + + clk = of_clk_get_by_name(np, "timerclk"); + if (IS_ERR(clk)) { + pr_err("clock get failed (%lu)\n", PTR_ERR(clk)); + return PTR_ERR(clk); + } + + ret = clk_prepare_enable(clk); + if (ret) { + pr_err("clock enable failed (%d)\n", ret); + goto err_clk_enable; + } + + base = of_iomap(np, 0); + if (!base) { + pr_err("unable to map registers\n"); + ret = -EADDRNOTAVAIL; + goto err_iomap; + } + + /* + * Disable and reset timer then set it to free running timer + * mode (CTCR) with no prescaler (PR) or match operations (MCR). + * After setup the timer is released from reset and enabled. + */ + writel_relaxed(LPC32XX_TIMER_TCR_CRST, base + LPC32XX_TIMER_TCR); + writel_relaxed(0, base + LPC32XX_TIMER_PR); + writel_relaxed(0, base + LPC32XX_TIMER_MCR); + writel_relaxed(0, base + LPC32XX_TIMER_CTCR); + writel_relaxed(LPC32XX_TIMER_TCR_CEN, base + LPC32XX_TIMER_TCR); + + rate = clk_get_rate(clk); + ret = clocksource_mmio_init(base + LPC32XX_TIMER_TC, "lpc3220 timer", + rate, 300, 32, clocksource_mmio_readl_up); + if (ret) { + pr_err("failed to init clocksource (%d)\n", ret); + goto err_clocksource_init; + } + + clocksource_timer_counter = base + LPC32XX_TIMER_TC; + sched_clock_register(lpc32xx_read_sched_clock, 32, rate); + + return 0; + +err_clocksource_init: + iounmap(base); +err_iomap: + clk_disable_unprepare(clk); +err_clk_enable: + clk_put(clk); + return ret; +} + +static int __init lpc32xx_clockevent_init(struct device_node *np) +{ + void __iomem *base; + unsigned long rate; + struct clk *clk; + int ret, irq; + + clk = of_clk_get_by_name(np, "timerclk"); + if (IS_ERR(clk)) { + pr_err("clock get failed (%lu)\n", PTR_ERR(clk)); + return PTR_ERR(clk); + } + + ret = clk_prepare_enable(clk); + if (ret) { + pr_err("clock enable failed (%d)\n", ret); + goto err_clk_enable; + } + + base = of_iomap(np, 0); + if (!base) { + pr_err("unable to map registers\n"); + ret = -EADDRNOTAVAIL; + goto err_iomap; + } + + irq = irq_of_parse_and_map(np, 0); + if (!irq) { + pr_err("get irq failed\n"); + ret = -ENOENT; + goto err_irq; + } + + /* + * Disable timer and clear any pending interrupt (IR) on match + * channel 0 (MR0). Configure a compare match value of 1 on MR0 + * and enable interrupt, reset on match and stop on match (MCR). + */ + writel_relaxed(0, base + LPC32XX_TIMER_TCR); + writel_relaxed(0, base + LPC32XX_TIMER_CTCR); + writel_relaxed(LPC32XX_TIMER_IR_MR0INT, base + LPC32XX_TIMER_IR); + writel_relaxed(1, base + LPC32XX_TIMER_MR0); + writel_relaxed(LPC32XX_TIMER_MCR_MR0I | LPC32XX_TIMER_MCR_MR0R | + LPC32XX_TIMER_MCR_MR0S, base + LPC32XX_TIMER_MCR); + + rate = clk_get_rate(clk); + lpc32xx_clk_event_ddata.base = base; + clockevents_config_and_register(&lpc32xx_clk_event_ddata.evtdev, + rate, 1, -1); + + ret = request_irq(irq, lpc32xx_clock_event_handler, + IRQF_TIMER | IRQF_IRQPOLL, "lpc3220 clockevent", + &lpc32xx_clk_event_ddata); + if (ret) { + pr_err("request irq failed\n"); + goto err_irq; + } + + return 0; + +err_irq: + iounmap(base); +err_iomap: + clk_disable_unprepare(clk); +err_clk_enable: + clk_put(clk); + return ret; +} + +/* + * This function asserts that we have exactly one clocksource and one + * clock_event_device in the end. + */ +static void __init lpc32xx_timer_init(struct device_node *np) +{ + static int has_clocksource, has_clockevent; + int ret; + + if (!has_clocksource) { + ret = lpc32xx_clocksource_init(np); + if (!ret) { + has_clocksource = 1; + return; + } + } + + if (!has_clockevent) { + ret = lpc32xx_clockevent_init(np); + if (!ret) { + has_clockevent = 1; + return; + } + } +} +CLOCKSOURCE_OF_DECLARE(lpc32xx_timer, "nxp,lpc3220-timer", lpc32xx_timer_init); diff --git a/drivers/clocksource/timer-stm32.c b/drivers/clocksource/timer-stm32.c new file mode 100644 index 0000000000000000000000000000000000000000..a97e8b50701cf964698bd9571f33c004c9f13665 --- /dev/null +++ b/drivers/clocksource/timer-stm32.c @@ -0,0 +1,184 @@ +/* + * Copyright (C) Maxime Coquelin 2015 + * Author: Maxime Coquelin + * License terms: GNU General Public License (GPL), version 2 + * + * Inspired by time-efm32.c from Uwe Kleine-Koenig + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define TIM_CR1 0x00 +#define TIM_DIER 0x0c +#define TIM_SR 0x10 +#define TIM_EGR 0x14 +#define TIM_PSC 0x28 +#define TIM_ARR 0x2c + +#define TIM_CR1_CEN BIT(0) +#define TIM_CR1_OPM BIT(3) +#define TIM_CR1_ARPE BIT(7) + +#define TIM_DIER_UIE BIT(0) + +#define TIM_SR_UIF BIT(0) + +#define TIM_EGR_UG BIT(0) + +struct stm32_clock_event_ddata { + struct clock_event_device evtdev; + unsigned periodic_top; + void __iomem *base; +}; + +static void stm32_clock_event_set_mode(enum clock_event_mode mode, + struct clock_event_device *evtdev) +{ + struct stm32_clock_event_ddata *data = + container_of(evtdev, struct stm32_clock_event_ddata, evtdev); + void *base = data->base; + + switch (mode) { + case CLOCK_EVT_MODE_PERIODIC: + writel_relaxed(data->periodic_top, base + TIM_ARR); + writel_relaxed(TIM_CR1_ARPE | TIM_CR1_CEN, base + TIM_CR1); + break; + + case CLOCK_EVT_MODE_ONESHOT: + default: + writel_relaxed(0, base + TIM_CR1); + break; + } +} + +static int stm32_clock_event_set_next_event(unsigned long evt, + struct clock_event_device *evtdev) +{ + struct stm32_clock_event_ddata *data = + container_of(evtdev, struct stm32_clock_event_ddata, evtdev); + + writel_relaxed(evt, data->base + TIM_ARR); + writel_relaxed(TIM_CR1_ARPE | TIM_CR1_OPM | TIM_CR1_CEN, + data->base + TIM_CR1); + + return 0; +} + +static irqreturn_t stm32_clock_event_handler(int irq, void *dev_id) +{ + struct stm32_clock_event_ddata *data = dev_id; + + writel_relaxed(0, data->base + TIM_SR); + + data->evtdev.event_handler(&data->evtdev); + + return IRQ_HANDLED; +} + +static struct stm32_clock_event_ddata clock_event_ddata = { + .evtdev = { + .name = "stm32 clockevent", + .features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_PERIODIC, + .set_mode = stm32_clock_event_set_mode, + .set_next_event = stm32_clock_event_set_next_event, + .rating = 200, + }, +}; + +static void __init stm32_clockevent_init(struct device_node *np) +{ + struct stm32_clock_event_ddata *data = &clock_event_ddata; + struct clk *clk; + struct reset_control *rstc; + unsigned long rate, max_delta; + int irq, ret, bits, prescaler = 1; + + clk = of_clk_get(np, 0); + if (IS_ERR(clk)) { + ret = PTR_ERR(clk); + pr_err("failed to get clock for clockevent (%d)\n", ret); + goto err_clk_get; + } + + ret = clk_prepare_enable(clk); + if (ret) { + pr_err("failed to enable timer clock for clockevent (%d)\n", + ret); + goto err_clk_enable; + } + + rate = clk_get_rate(clk); + + rstc = of_reset_control_get(np, NULL); + if (!IS_ERR(rstc)) { + reset_control_assert(rstc); + reset_control_deassert(rstc); + } + + data->base = of_iomap(np, 0); + if (!data->base) { + pr_err("failed to map registers for clockevent\n"); + goto err_iomap; + } + + irq = irq_of_parse_and_map(np, 0); + if (!irq) { + pr_err("%s: failed to get irq.\n", np->full_name); + goto err_get_irq; + } + + /* Detect whether the timer is 16 or 32 bits */ + writel_relaxed(~0U, data->base + TIM_ARR); + max_delta = readl_relaxed(data->base + TIM_ARR); + if (max_delta == ~0U) { + prescaler = 1; + bits = 32; + } else { + prescaler = 1024; + bits = 16; + } + writel_relaxed(0, data->base + TIM_ARR); + + writel_relaxed(prescaler - 1, data->base + TIM_PSC); + writel_relaxed(TIM_EGR_UG, data->base + TIM_EGR); + writel_relaxed(TIM_DIER_UIE, data->base + TIM_DIER); + writel_relaxed(0, data->base + TIM_SR); + + data->periodic_top = DIV_ROUND_CLOSEST(rate, prescaler * HZ); + + clockevents_config_and_register(&data->evtdev, + DIV_ROUND_CLOSEST(rate, prescaler), + 0x1, max_delta); + + ret = request_irq(irq, stm32_clock_event_handler, IRQF_TIMER, + "stm32 clockevent", data); + if (ret) { + pr_err("%s: failed to request irq.\n", np->full_name); + goto err_get_irq; + } + + pr_info("%s: STM32 clockevent driver initialized (%d bits)\n", + np->full_name, bits); + + return; + +err_get_irq: + iounmap(data->base); +err_iomap: + clk_disable_unprepare(clk); +err_clk_enable: + clk_put(clk); +err_clk_get: + return; +} + +CLOCKSOURCE_OF_DECLARE(stm32, "st,stm32-timer", stm32_clockevent_init);