u-boot/arch/arm/cpu/arm926ejs/pantheon/timer.c
Simon Glass 66ee692347 arm: Move tbl to arch_global_data
Move this field into arch_global_data and tidy up.

Signed-off-by: Simon Glass <sjg@chromium.org>
2013-02-01 15:07:50 -05:00

217 lines
5.4 KiB
C

/*
* (C) Copyright 2011
* Marvell Semiconductor <www.marvell.com>
* Written-by: Lei Wen <leiwen@marvell.com>
*
* See file CREDITS for list of people who contributed to this
* project.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
* MA 02110-1301 USA
*/
#include <common.h>
#include <asm/arch/cpu.h>
#include <asm/arch/pantheon.h>
/*
* Timer registers
* Refer 6.2.9 in Datasheet
*/
struct panthtmr_registers {
u32 clk_ctrl; /* Timer clk control reg */
u32 match[9]; /* Timer match registers */
u32 count[3]; /* Timer count registers */
u32 status[3];
u32 ie[3];
u32 preload[3]; /* Timer preload value */
u32 preload_ctrl[3];
u32 wdt_match_en;
u32 wdt_match_r;
u32 wdt_val;
u32 wdt_sts;
u32 icr[3];
u32 wdt_icr;
u32 cer; /* Timer count enable reg */
u32 cmr;
u32 ilr[3];
u32 wcr;
u32 wfar;
u32 wsar;
u32 cvwr[3];
};
#define TIMER 0 /* Use TIMER 0 */
/* Each timer has 3 match registers */
#define MATCH_CMP(x) ((3 * TIMER) + x)
#define TIMER_LOAD_VAL 0xffffffff
#define COUNT_RD_REQ 0x1
DECLARE_GLOBAL_DATA_PTR;
/* Using gd->arch.tbu from timestamp and gd->arch.tbl for lastdec */
/*
* For preventing risk of instability in reading counter value,
* first set read request to register cvwr and then read same
* register after it captures counter value.
*/
ulong read_timer(void)
{
struct panthtmr_registers *panthtimers =
(struct panthtmr_registers *) PANTHEON_TIMER_BASE;
volatile int loop=100;
ulong val;
writel(COUNT_RD_REQ, &panthtimers->cvwr);
while (loop--)
val = readl(&panthtimers->cvwr);
/*
* This stop gcc complain and prevent loop mistake init to 0
*/
val = readl(&panthtimers->cvwr);
return val;
}
ulong get_timer_masked(void)
{
ulong now = read_timer();
if (now >= gd->arch.tbl) {
/* normal mode */
gd->arch.tbu += now - gd->arch.tbl;
} else {
/* we have an overflow ... */
gd->arch.tbu += now + TIMER_LOAD_VAL - gd->arch.tbl;
}
gd->arch.tbl = now;
return gd->arch.tbu;
}
ulong get_timer(ulong base)
{
return ((get_timer_masked() / (CONFIG_SYS_HZ_CLOCK / 1000)) -
base);
}
void __udelay(unsigned long usec)
{
ulong delayticks;
ulong endtime;
delayticks = (usec * (CONFIG_SYS_HZ_CLOCK / 1000000));
endtime = get_timer_masked() + delayticks;
while (get_timer_masked() < endtime)
;
}
/*
* init the Timer
*/
int timer_init(void)
{
struct panthapb_registers *apb1clkres =
(struct panthapb_registers *) PANTHEON_APBC_BASE;
struct panthtmr_registers *panthtimers =
(struct panthtmr_registers *) PANTHEON_TIMER_BASE;
/* Enable Timer clock at 3.25 MHZ */
writel(APBC_APBCLK | APBC_FNCLK | APBC_FNCLKSEL(3), &apb1clkres->timers);
/* load value into timer */
writel(0x0, &panthtimers->clk_ctrl);
/* Use Timer 0 Match Resiger 0 */
writel(TIMER_LOAD_VAL, &panthtimers->match[MATCH_CMP(0)]);
/* Preload value is 0 */
writel(0x0, &panthtimers->preload[TIMER]);
/* Enable match comparator 0 for Timer 0 */
writel(0x1, &panthtimers->preload_ctrl[TIMER]);
/* Enable timer 0 */
writel(0x1, &panthtimers->cer);
/* init the gd->arch.tbu and gd->arch.tbl value */
gd->arch.tbl = read_timer();
gd->arch.tbu = 0;
return 0;
}
#define MPMU_APRR_WDTR (1<<4)
#define TMR_WFAR 0xbaba /* WDT Register First key */
#define TMP_WSAR 0xeb10 /* WDT Register Second key */
/*
* This function uses internal Watchdog Timer
* based reset mechanism.
* Steps to write watchdog registers (protected access)
* 1. Write key value to TMR_WFAR reg.
* 2. Write key value to TMP_WSAR reg.
* 3. Perform write operation.
*/
void reset_cpu (unsigned long ignored)
{
struct panthmpmu_registers *mpmu =
(struct panthmpmu_registers *) PANTHEON_MPMU_BASE;
struct panthtmr_registers *panthtimers =
(struct panthtmr_registers *) PANTHEON_WD_TIMER_BASE;
u32 val;
/* negate hardware reset to the WDT after system reset */
val = readl(&mpmu->aprr);
val = val | MPMU_APRR_WDTR;
writel(val, &mpmu->aprr);
/* reset/enable WDT clock */
writel(APBC_APBCLK, &mpmu->wdtpcr);
/* clear previous WDT status */
writel(TMR_WFAR, &panthtimers->wfar);
writel(TMP_WSAR, &panthtimers->wsar);
writel(0, &panthtimers->wdt_sts);
/* set match counter */
writel(TMR_WFAR, &panthtimers->wfar);
writel(TMP_WSAR, &panthtimers->wsar);
writel(0xf, &panthtimers->wdt_match_r);
/* enable WDT reset */
writel(TMR_WFAR, &panthtimers->wfar);
writel(TMP_WSAR, &panthtimers->wsar);
writel(0x3, &panthtimers->wdt_match_en);
/*enable functional WDT clock */
writel(APBC_APBCLK | APBC_FNCLK, &mpmu->wdtpcr);
}
/*
* 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 (ulong)CONFIG_SYS_HZ;
}