u-boot/arch/arm/mach-imx/timer.c

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/*
* (C) Copyright 2007
* Sascha Hauer, Pengutronix
*
* (C) Copyright 2009 Freescale Semiconductor, Inc.
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <asm/io.h>
#include <div64.h>
#include <asm/arch/imx-regs.h>
#include <asm/arch/clock.h>
#include <asm/arch/sys_proto.h>
/* General purpose timers registers */
struct mxc_gpt {
unsigned int control;
unsigned int prescaler;
unsigned int status;
unsigned int nouse[6];
unsigned int counter;
};
static struct mxc_gpt *cur_gpt = (struct mxc_gpt *)GPT1_BASE_ADDR;
/* General purpose timers bitfields */
#define GPTCR_SWR (1 << 15) /* Software reset */
#define GPTCR_24MEN (1 << 10) /* Enable 24MHz clock input */
#define GPTCR_FRR (1 << 9) /* Freerun / restart */
#define GPTCR_CLKSOURCE_32 (4 << 6) /* Clock source 32khz */
#define GPTCR_CLKSOURCE_OSC (5 << 6) /* Clock source OSC */
#define GPTCR_CLKSOURCE_PRE (1 << 6) /* Clock source PRECLK */
#define GPTCR_CLKSOURCE_MASK (0x7 << 6)
#define GPTCR_TEN 1 /* Timer enable */
#define GPTPR_PRESCALER24M_SHIFT 12
#define GPTPR_PRESCALER24M_MASK (0xF << GPTPR_PRESCALER24M_SHIFT)
DECLARE_GLOBAL_DATA_PTR;
static inline int gpt_has_clk_source_osc(void)
{
#if defined(CONFIG_MX6)
if (((is_mx6dq()) && (soc_rev() > CHIP_REV_1_0)) ||
is_mx6dqp() || is_mx6sdl() || is_mx6sx() || is_mx6ul() ||
is_mx6ull() || is_mx6sll())
return 1;
return 0;
#else
return 0;
#endif
}
static inline ulong gpt_get_clk(void)
{
#ifdef CONFIG_MXC_GPT_HCLK
if (gpt_has_clk_source_osc())
return MXC_HCLK >> 3;
else
return mxc_get_clock(MXC_IPG_PERCLK);
#else
return MXC_CLK32;
#endif
}
int timer_init(void)
{
int i;
/* setup GP Timer 1 */
__raw_writel(GPTCR_SWR, &cur_gpt->control);
/* We have no udelay by now */
for (i = 0; i < 100; i++)
__raw_writel(0, &cur_gpt->control);
i = __raw_readl(&cur_gpt->control);
i &= ~GPTCR_CLKSOURCE_MASK;
#ifdef CONFIG_MXC_GPT_HCLK
if (gpt_has_clk_source_osc()) {
i |= GPTCR_CLKSOURCE_OSC | GPTCR_TEN;
/*
* For DL/S, SX, UL, ULL, SLL set 24Mhz OSC
* Enable bit and prescaler
*/
if (is_mx6sdl() || is_mx6sx() || is_mx6ul() || is_mx6ull() ||
is_mx6sll()) {
i |= GPTCR_24MEN;
/* Produce 3Mhz clock */
__raw_writel((7 << GPTPR_PRESCALER24M_SHIFT),
&cur_gpt->prescaler);
}
} else {
i |= GPTCR_CLKSOURCE_PRE | GPTCR_TEN;
}
#else
__raw_writel(0, &cur_gpt->prescaler); /* 32Khz */
i |= GPTCR_CLKSOURCE_32 | GPTCR_TEN;
#endif
__raw_writel(i, &cur_gpt->control);
return 0;
}
unsigned long timer_read_counter(void)
{
return __raw_readl(&cur_gpt->counter); /* current tick value */
}
/*
* 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 gpt_get_clk();
}
/*
* This function is intended for SHORT delays only.
* It will overflow at around 10 seconds @ 400MHz,
* or 20 seconds @ 200MHz.
*/
unsigned long usec2ticks(unsigned long _usec)
{
unsigned long long usec = _usec;
usec *= get_tbclk();
usec += 999999;
do_div(usec, 1000000);
return usec;
}