diff options
Diffstat (limited to 'arch/arm/mach-stm32/stm32f7/timer.c')
-rw-r--r-- | arch/arm/mach-stm32/stm32f7/timer.c | 112 |
1 files changed, 112 insertions, 0 deletions
diff --git a/arch/arm/mach-stm32/stm32f7/timer.c b/arch/arm/mach-stm32/stm32f7/timer.c new file mode 100644 index 0000000000..a7dee1044d --- /dev/null +++ b/arch/arm/mach-stm32/stm32f7/timer.c @@ -0,0 +1,112 @@ +/* + * (C) Copyright 2016 + * Vikas Manocha, ST Micoelectronics, vikas.manocha@st.com. + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#include <common.h> +#include <asm/io.h> +#include <asm/arch/stm32.h> +#include <asm/arch/gpt.h> +#include <asm/arch/rcc.h> + +#define READ_TIMER() (readl(&gpt1_regs_ptr->cnt) & GPT_FREE_RUNNING) +#define GPT_RESOLUTION (CONFIG_SYS_HZ_CLOCK/CONFIG_STM32_HZ) + +DECLARE_GLOBAL_DATA_PTR; + +#define timestamp gd->arch.tbl +#define lastdec gd->arch.lastinc + +int timer_init(void) +{ + /* Timer2 clock configuration */ + setbits_le32(RCC_BASE + RCC_APB1ENR, RCC_APB1ENR_TIM2EN); + /* Stop the timer */ + writel(readl(&gpt1_regs_ptr->cr1) & ~GPT_CR1_CEN, &gpt1_regs_ptr->cr1); + + writel((CONFIG_SYS_CLK_FREQ/CONFIG_SYS_HZ_CLOCK) - 1, + &gpt1_regs_ptr->psc); + + /* Configure timer for auto-reload */ + writel(readl(&gpt1_regs_ptr->cr1) | GPT_MODE_AUTO_RELOAD, + &gpt1_regs_ptr->cr1); + + /* load value for free running */ + writel(GPT_FREE_RUNNING, &gpt1_regs_ptr->arr); + + /* start timer */ + writel(readl(&gpt1_regs_ptr->cr1) | GPT_CR1_CEN, &gpt1_regs_ptr->cr1); + + writel(readl(&gpt1_regs_ptr->egr) | TIM_EGR_UG, &gpt1_regs_ptr->egr); + + /* Reset the timer */ + lastdec = READ_TIMER(); + timestamp = 0; + + return 0; +} + +/* + * timer without interrupts + */ +ulong get_timer(ulong base) +{ + return (get_timer_masked() / GPT_RESOLUTION) - base; +} + +void __udelay(unsigned long usec) +{ + ulong tmo; + ulong start = get_timer_masked(); + ulong tenudelcnt = CONFIG_SYS_HZ_CLOCK / (1000 * 100); + ulong rndoff; + + rndoff = (usec % 10) ? 1 : 0; + + /* tenudelcnt timer tick gives 10 microsecconds delay */ + tmo = ((usec / 10) + rndoff) * tenudelcnt; + + while ((ulong) (get_timer_masked() - start) < tmo) + ; +} + +ulong get_timer_masked(void) +{ + ulong now = READ_TIMER(); + + if (now >= lastdec) { + /* normal mode */ + timestamp += now - lastdec; + } else { + /* we have an overflow ... */ + timestamp += now + GPT_FREE_RUNNING - lastdec; + } + lastdec = now; + + return timestamp; +} + +void udelay_masked(unsigned long usec) +{ + return udelay(usec); +} + +/* + * This function is derived from PowerPC code (read timebase as long long). + * On ARM it just returns the timer value. + */ +unsigned long long get_ticks(void) +{ + return get_timer(0); +} + +/* + * This function is derived from PowerPC code (timebase clock frequency). + * On ARM it returns the number of timer ticks per second. + */ +ulong get_tbclk(void) +{ + return CONFIG_STM32_HZ; +} |