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- // SPDX-License-Identifier: GPL-2.0+
- /*
- * Freescale i.MX28 timer driver
- *
- * Copyright (C) 2011 Marek Vasut <marek.vasut@gmail.com>
- * on behalf of DENX Software Engineering GmbH
- *
- * Based on code from LTIB:
- * (C) Copyright 2009-2010 Freescale Semiconductor, Inc.
- */
- #include <common.h>
- #include <init.h>
- #include <time.h>
- #include <asm/io.h>
- #include <asm/arch/imx-regs.h>
- #include <asm/arch/sys_proto.h>
- #include <linux/delay.h>
- /* Maximum fixed count */
- #if defined(CONFIG_MX23)
- #define TIMER_LOAD_VAL 0xffff
- #elif defined(CONFIG_MX28)
- #define TIMER_LOAD_VAL 0xffffffff
- #endif
- DECLARE_GLOBAL_DATA_PTR;
- #define timestamp (gd->arch.tbl)
- #define lastdec (gd->arch.lastinc)
- /*
- * This driver uses 1kHz clock source.
- */
- #define MXS_INCREMENTER_HZ 1000
- static inline unsigned long tick_to_time(unsigned long tick)
- {
- return tick / (MXS_INCREMENTER_HZ / CONFIG_SYS_HZ);
- }
- static inline unsigned long time_to_tick(unsigned long time)
- {
- return time * (MXS_INCREMENTER_HZ / CONFIG_SYS_HZ);
- }
- /* Calculate how many ticks happen in "us" microseconds */
- static inline unsigned long us_to_tick(unsigned long us)
- {
- return (us * MXS_INCREMENTER_HZ) / 1000000;
- }
- int timer_init(void)
- {
- struct mxs_timrot_regs *timrot_regs =
- (struct mxs_timrot_regs *)MXS_TIMROT_BASE;
- /* Reset Timers and Rotary Encoder module */
- mxs_reset_block(&timrot_regs->hw_timrot_rotctrl_reg);
- /* Set fixed_count to 0 */
- #if defined(CONFIG_MX23)
- writel(0, &timrot_regs->hw_timrot_timcount0);
- #elif defined(CONFIG_MX28)
- writel(0, &timrot_regs->hw_timrot_fixed_count0);
- #endif
- /* Set UPDATE bit and 1Khz frequency */
- writel(TIMROT_TIMCTRLn_UPDATE | TIMROT_TIMCTRLn_RELOAD |
- TIMROT_TIMCTRLn_SELECT_1KHZ_XTAL,
- &timrot_regs->hw_timrot_timctrl0);
- /* Set fixed_count to maximal value */
- #if defined(CONFIG_MX23)
- writel(TIMER_LOAD_VAL - 1, &timrot_regs->hw_timrot_timcount0);
- #elif defined(CONFIG_MX28)
- writel(TIMER_LOAD_VAL, &timrot_regs->hw_timrot_fixed_count0);
- #endif
- return 0;
- }
- unsigned long long get_ticks(void)
- {
- struct mxs_timrot_regs *timrot_regs =
- (struct mxs_timrot_regs *)MXS_TIMROT_BASE;
- uint32_t now;
- /* Current tick value */
- #if defined(CONFIG_MX23)
- /* Upper bits are the valid ones. */
- now = readl(&timrot_regs->hw_timrot_timcount0) >>
- TIMROT_RUNNING_COUNTn_RUNNING_COUNT_OFFSET;
- #elif defined(CONFIG_MX28)
- now = readl(&timrot_regs->hw_timrot_running_count0);
- #else
- #error "Don't know how to read timrot_regs"
- #endif
- if (lastdec >= now) {
- /*
- * normal mode (non roll)
- * move stamp forward with absolut diff ticks
- */
- timestamp += (lastdec - now);
- } else {
- /* we have rollover of decrementer */
- timestamp += (TIMER_LOAD_VAL - now) + lastdec;
- }
- lastdec = now;
- return timestamp;
- }
- ulong get_timer(ulong base)
- {
- return tick_to_time(get_ticks()) - base;
- }
- /* We use the HW_DIGCTL_MICROSECONDS register for sub-millisecond timer. */
- #define MXS_HW_DIGCTL_MICROSECONDS 0x8001c0c0
- void __udelay(unsigned long usec)
- {
- uint32_t old, new, incr;
- uint32_t counter = 0;
- old = readl(MXS_HW_DIGCTL_MICROSECONDS);
- while (counter < usec) {
- new = readl(MXS_HW_DIGCTL_MICROSECONDS);
- /* Check if the timer wrapped. */
- if (new < old) {
- incr = 0xffffffff - old;
- incr += new;
- } else {
- incr = new - old;
- }
- /*
- * Check if we are close to the maximum time and the counter
- * would wrap if incremented. If that's the case, break out
- * from the loop as the requested delay time passed.
- */
- if (counter + incr < counter)
- break;
- counter += incr;
- old = new;
- }
- }
- ulong get_tbclk(void)
- {
- return MXS_INCREMENTER_HZ;
- }
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