mirror of
https://github.com/brain-hackers/u-boot-brain
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83d290c56f
When U-Boot started using SPDX tags we were among the early adopters and there weren't a lot of other examples to borrow from. So we picked the area of the file that usually had a full license text and replaced it with an appropriate SPDX-License-Identifier: entry. Since then, the Linux Kernel has adopted SPDX tags and they place it as the very first line in a file (except where shebangs are used, then it's second line) and with slightly different comment styles than us. In part due to community overlap, in part due to better tag visibility and in part for other minor reasons, switch over to that style. This commit changes all instances where we have a single declared license in the tag as both the before and after are identical in tag contents. There's also a few places where I found we did not have a tag and have introduced one. Signed-off-by: Tom Rini <trini@konsulko.com>
161 lines
3.5 KiB
C
161 lines
3.5 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* Freescale i.MX28 timer driver
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*
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* Copyright (C) 2011 Marek Vasut <marek.vasut@gmail.com>
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* on behalf of DENX Software Engineering GmbH
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*
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* Based on code from LTIB:
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* (C) Copyright 2009-2010 Freescale Semiconductor, Inc.
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*/
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#include <common.h>
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#include <asm/io.h>
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#include <asm/arch/imx-regs.h>
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#include <asm/arch/sys_proto.h>
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/* Maximum fixed count */
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#if defined(CONFIG_MX23)
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#define TIMER_LOAD_VAL 0xffff
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#elif defined(CONFIG_MX28)
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#define TIMER_LOAD_VAL 0xffffffff
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#endif
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DECLARE_GLOBAL_DATA_PTR;
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#define timestamp (gd->arch.tbl)
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#define lastdec (gd->arch.lastinc)
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/*
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* This driver uses 1kHz clock source.
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*/
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#define MXS_INCREMENTER_HZ 1000
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static inline unsigned long tick_to_time(unsigned long tick)
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{
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return tick / (MXS_INCREMENTER_HZ / CONFIG_SYS_HZ);
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}
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static inline unsigned long time_to_tick(unsigned long time)
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{
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return time * (MXS_INCREMENTER_HZ / CONFIG_SYS_HZ);
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}
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/* Calculate how many ticks happen in "us" microseconds */
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static inline unsigned long us_to_tick(unsigned long us)
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{
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return (us * MXS_INCREMENTER_HZ) / 1000000;
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}
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int timer_init(void)
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{
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struct mxs_timrot_regs *timrot_regs =
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(struct mxs_timrot_regs *)MXS_TIMROT_BASE;
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/* Reset Timers and Rotary Encoder module */
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mxs_reset_block(&timrot_regs->hw_timrot_rotctrl_reg);
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/* Set fixed_count to 0 */
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#if defined(CONFIG_MX23)
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writel(0, &timrot_regs->hw_timrot_timcount0);
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#elif defined(CONFIG_MX28)
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writel(0, &timrot_regs->hw_timrot_fixed_count0);
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#endif
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/* Set UPDATE bit and 1Khz frequency */
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writel(TIMROT_TIMCTRLn_UPDATE | TIMROT_TIMCTRLn_RELOAD |
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TIMROT_TIMCTRLn_SELECT_1KHZ_XTAL,
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&timrot_regs->hw_timrot_timctrl0);
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/* Set fixed_count to maximal value */
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#if defined(CONFIG_MX23)
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writel(TIMER_LOAD_VAL - 1, &timrot_regs->hw_timrot_timcount0);
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#elif defined(CONFIG_MX28)
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writel(TIMER_LOAD_VAL, &timrot_regs->hw_timrot_fixed_count0);
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#endif
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return 0;
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}
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unsigned long long get_ticks(void)
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{
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struct mxs_timrot_regs *timrot_regs =
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(struct mxs_timrot_regs *)MXS_TIMROT_BASE;
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uint32_t now;
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/* Current tick value */
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#if defined(CONFIG_MX23)
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/* Upper bits are the valid ones. */
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now = readl(&timrot_regs->hw_timrot_timcount0) >>
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TIMROT_RUNNING_COUNTn_RUNNING_COUNT_OFFSET;
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#elif defined(CONFIG_MX28)
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now = readl(&timrot_regs->hw_timrot_running_count0);
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#else
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#error "Don't know how to read timrot_regs"
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#endif
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if (lastdec >= now) {
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/*
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* normal mode (non roll)
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* move stamp forward with absolut diff ticks
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*/
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timestamp += (lastdec - now);
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} else {
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/* we have rollover of decrementer */
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timestamp += (TIMER_LOAD_VAL - now) + lastdec;
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}
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lastdec = now;
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return timestamp;
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}
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ulong get_timer_masked(void)
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{
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return tick_to_time(get_ticks());
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}
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ulong get_timer(ulong base)
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{
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return get_timer_masked() - base;
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}
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/* We use the HW_DIGCTL_MICROSECONDS register for sub-millisecond timer. */
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#define MXS_HW_DIGCTL_MICROSECONDS 0x8001c0c0
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void __udelay(unsigned long usec)
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{
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uint32_t old, new, incr;
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uint32_t counter = 0;
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old = readl(MXS_HW_DIGCTL_MICROSECONDS);
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while (counter < usec) {
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new = readl(MXS_HW_DIGCTL_MICROSECONDS);
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/* Check if the timer wrapped. */
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if (new < old) {
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incr = 0xffffffff - old;
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incr += new;
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} else {
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incr = new - old;
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}
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/*
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* Check if we are close to the maximum time and the counter
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* would wrap if incremented. If that's the case, break out
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* from the loop as the requested delay time passed.
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*/
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if (counter + incr < counter)
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break;
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counter += incr;
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old = new;
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}
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}
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ulong get_tbclk(void)
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{
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return MXS_INCREMENTER_HZ;
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}
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