diff options
author | Otavio Salvador <otavio@ossystems.com.br> | 2012-08-05 09:05:29 +0000 |
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committer | Albert ARIBAUD <albert.u.boot@aribaud.net> | 2012-09-01 14:58:17 +0200 |
commit | 3a0398d7b916eed6ae80427626f0434690ca0da0 (patch) | |
tree | 6df395fa52909a8977f38df93533a1a5a701df9d /arch/arm/cpu/arm926ejs/mxs/timer.c | |
parent | d369d53d9c438a5d0df157586dcd072de48d9631 (diff) |
mxs: reorganize source directory for easy sharing of code in i.MXS SoCs
Most code can be shared between i.MX23 and i.MX28 as both are from
i.MXS family; this source directory structure makes easy to share code
among them.
Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
Acked-by: Stefano Babic <sbabic@denx.de>
Diffstat (limited to 'arch/arm/cpu/arm926ejs/mxs/timer.c')
-rw-r--r-- | arch/arm/cpu/arm926ejs/mxs/timer.c | 156 |
1 files changed, 156 insertions, 0 deletions
diff --git a/arch/arm/cpu/arm926ejs/mxs/timer.c b/arch/arm/cpu/arm926ejs/mxs/timer.c new file mode 100644 index 0000000000..5b73f4a2b3 --- /dev/null +++ b/arch/arm/cpu/arm926ejs/mxs/timer.c @@ -0,0 +1,156 @@ +/* + * 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. + * + * 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., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + */ + +#include <common.h> +#include <asm/io.h> +#include <asm/arch/imx-regs.h> +#include <asm/arch/sys_proto.h> + +/* Maximum fixed count */ +#define TIMER_LOAD_VAL 0xffffffff + +DECLARE_GLOBAL_DATA_PTR; + +#define timestamp (gd->tbl) +#define lastdec (gd->lastinc) + +/* + * This driver uses 1kHz clock source. + */ +#define MX28_INCREMENTER_HZ 1000 + +static inline unsigned long tick_to_time(unsigned long tick) +{ + return tick / (MX28_INCREMENTER_HZ / CONFIG_SYS_HZ); +} + +static inline unsigned long time_to_tick(unsigned long time) +{ + return time * (MX28_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 * MX28_INCREMENTER_HZ) / 1000000; +} + +int timer_init(void) +{ + struct mx28_timrot_regs *timrot_regs = + (struct mx28_timrot_regs *)MXS_TIMROT_BASE; + + /* Reset Timers and Rotary Encoder module */ + mx28_reset_block(&timrot_regs->hw_timrot_rotctrl_reg); + + /* Set fixed_count to 0 */ + writel(0, &timrot_regs->hw_timrot_fixed_count0); + + /* 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 */ + writel(TIMER_LOAD_VAL, &timrot_regs->hw_timrot_fixed_count0); + + return 0; +} + +unsigned long long get_ticks(void) +{ + struct mx28_timrot_regs *timrot_regs = + (struct mx28_timrot_regs *)MXS_TIMROT_BASE; + + /* Current tick value */ + uint32_t now = readl(&timrot_regs->hw_timrot_running_count0); + + 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_masked(void) +{ + return tick_to_time(get_ticks()); +} + +ulong get_timer(ulong base) +{ + return get_timer_masked() - base; +} + +/* We use the HW_DIGCTL_MICROSECONDS register for sub-millisecond timer. */ +#define MX28_HW_DIGCTL_MICROSECONDS 0x8001c0c0 + +void __udelay(unsigned long usec) +{ + uint32_t old, new, incr; + uint32_t counter = 0; + + old = readl(MX28_HW_DIGCTL_MICROSECONDS); + + while (counter < usec) { + new = readl(MX28_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 MX28_INCREMENTER_HZ; +} |