uefi/arm-trusted-firmware/plat/hikey/drivers/sp804_timer.c

/*
 * Copyright (c) 2014-2015, Linaro Ltd and Contributors. All rights reserved.
 * Copyright (c) 2014-2015, Hisilicon Ltd and Contributors. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * Redistributions of source code must retain the above copyright notice, this
 * list of conditions and the following disclaimer.
 *
 * Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 *
 * Neither the name of ARM nor the names of its contributors may be used
 * to endorse or promote products derived from this software without specific
 * prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <console.h>
#include <debug.h>
#include <errno.h>
#include <hi6220.h>
#include <mmio.h>
#include <sp804_timer.h>

/* Init dual timer0 (TIMER00 & TIMER01) */
void hi6220_timer_init(void)
{
	unsigned int data;

	/* select 32KHz as the clock of dual timer0 */
	/* FIXME: But I find that it's 19.2MHz, not 32KHz. */
	data = mmio_read_32(AO_SC_TIMER_EN0);
	while (data & 3) {
		data &= ~3;
		data |= 3 << 16;
		mmio_write_32(AO_SC_TIMER_EN0, data);
		data = mmio_read_32(AO_SC_TIMER_EN0);
	}
	/* enable the pclk of dual timer0 */
	data = mmio_read_32(AO_SC_PERIPH_CLKSTAT4);
	while (!(data & PCLK_TIMER1) || !(data & PCLK_TIMER0)) {
		mmio_write_32(AO_SC_PERIPH_CLKEN4, PCLK_TIMER1 | PCLK_TIMER0);
		data = mmio_read_32(AO_SC_PERIPH_CLKSTAT4);
	}
	/* reset dual timer0 */
	data = mmio_read_32(AO_SC_PERIPH_RSTSTAT4);
	mmio_write_32(AO_SC_PERIPH_RSTEN4, PCLK_TIMER1 | PCLK_TIMER0);
	do {
		data = mmio_read_32(AO_SC_PERIPH_RSTSTAT4);
	} while (!(data & PCLK_TIMER1) || !(data & PCLK_TIMER0));
	/* unreset dual timer0 */
	mmio_write_32(AO_SC_PERIPH_RSTDIS4, PCLK_TIMER1 | PCLK_TIMER0);
	do {
		data = mmio_read_32(AO_SC_PERIPH_RSTSTAT4);
	} while ((data & PCLK_TIMER1) || (data & PCLK_TIMER0));
	
	/* disable timer00 */
	mmio_write_32(TIMER00_CONTROL, 0);
	mmio_write_32(TIMER00_LOAD, 0xffffffff);
	/* free running */
	mmio_write_32(TIMER00_CONTROL, 0x82);
}

static unsigned int get_timer_value(void)
{
	return mmio_read_32(TIMER00_VALUE);
}

void udelay(int us)
{
	unsigned int start, cnt, delta, delta_us;

	if (us <= 0)
		us = 1;
	/* counter is decreasing */
	start = get_timer_value();
	do {
		cnt = get_timer_value();
		if (cnt > start) {
			delta = 0xffffffff - cnt;
			delta += start;
		} else
			delta = start - cnt;
		delta_us = (delta * 10) / 192;
	} while (delta_us < us);
}

void mdelay(int ms)
{
	unsigned int start, cnt, delta, delta_ms;

	if (ms <= 0)
		ms = 1;

	/* counter is decreasing */
	start = get_timer_value();
	do {
		cnt = get_timer_value();
		if (cnt > start) {
			delta = 0xffffffff - cnt;
			delta += start;
		} else
			delta = start - cnt;
		delta_ms = delta / 19200;
	} while (delta_ms < ms);
}