423 lines
16 KiB
C
423 lines
16 KiB
C
/*
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*
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* arch/arm/mach-u300/timer.c
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*
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*
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* Copyright (C) 2007-2009 ST-Ericsson AB
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* License terms: GNU General Public License (GPL) version 2
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* Timer COH 901 328, runs the OS timer interrupt.
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* Author: Linus Walleij <linus.walleij@stericsson.com>
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*/
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#include <linux/interrupt.h>
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#include <linux/time.h>
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#include <linux/timex.h>
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#include <linux/clockchips.h>
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#include <linux/clocksource.h>
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#include <linux/types.h>
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#include <linux/io.h>
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#include <mach/hardware.h>
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/* Generic stuff */
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#include <asm/mach/map.h>
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#include <asm/mach/time.h>
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#include <asm/mach/irq.h>
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#include "clock.h"
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/*
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* APP side special timer registers
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* This timer contains four timers which can fire an interrupt each.
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* OS (operating system) timer @ 32768 Hz
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* DD (device driver) timer @ 1 kHz
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* GP1 (general purpose 1) timer @ 1MHz
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* GP2 (general purpose 2) timer @ 1MHz
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*/
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/* Reset OS Timer 32bit (-/W) */
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#define U300_TIMER_APP_ROST (0x0000)
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#define U300_TIMER_APP_ROST_TIMER_RESET (0x00000000)
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/* Enable OS Timer 32bit (-/W) */
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#define U300_TIMER_APP_EOST (0x0004)
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#define U300_TIMER_APP_EOST_TIMER_ENABLE (0x00000000)
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/* Disable OS Timer 32bit (-/W) */
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#define U300_TIMER_APP_DOST (0x0008)
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#define U300_TIMER_APP_DOST_TIMER_DISABLE (0x00000000)
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/* OS Timer Mode Register 32bit (-/W) */
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#define U300_TIMER_APP_SOSTM (0x000c)
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#define U300_TIMER_APP_SOSTM_MODE_CONTINUOUS (0x00000000)
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#define U300_TIMER_APP_SOSTM_MODE_ONE_SHOT (0x00000001)
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/* OS Timer Status Register 32bit (R/-) */
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#define U300_TIMER_APP_OSTS (0x0010)
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#define U300_TIMER_APP_OSTS_TIMER_STATE_MASK (0x0000000F)
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#define U300_TIMER_APP_OSTS_TIMER_STATE_IDLE (0x00000001)
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#define U300_TIMER_APP_OSTS_TIMER_STATE_ACTIVE (0x00000002)
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#define U300_TIMER_APP_OSTS_ENABLE_IND (0x00000010)
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#define U300_TIMER_APP_OSTS_MODE_MASK (0x00000020)
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#define U300_TIMER_APP_OSTS_MODE_CONTINUOUS (0x00000000)
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#define U300_TIMER_APP_OSTS_MODE_ONE_SHOT (0x00000020)
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#define U300_TIMER_APP_OSTS_IRQ_ENABLED_IND (0x00000040)
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#define U300_TIMER_APP_OSTS_IRQ_PENDING_IND (0x00000080)
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/* OS Timer Current Count Register 32bit (R/-) */
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#define U300_TIMER_APP_OSTCC (0x0014)
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/* OS Timer Terminal Count Register 32bit (R/W) */
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#define U300_TIMER_APP_OSTTC (0x0018)
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/* OS Timer Interrupt Enable Register 32bit (-/W) */
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#define U300_TIMER_APP_OSTIE (0x001c)
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#define U300_TIMER_APP_OSTIE_IRQ_DISABLE (0x00000000)
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#define U300_TIMER_APP_OSTIE_IRQ_ENABLE (0x00000001)
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/* OS Timer Interrupt Acknowledge Register 32bit (-/W) */
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#define U300_TIMER_APP_OSTIA (0x0020)
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#define U300_TIMER_APP_OSTIA_IRQ_ACK (0x00000080)
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/* Reset DD Timer 32bit (-/W) */
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#define U300_TIMER_APP_RDDT (0x0040)
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#define U300_TIMER_APP_RDDT_TIMER_RESET (0x00000000)
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/* Enable DD Timer 32bit (-/W) */
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#define U300_TIMER_APP_EDDT (0x0044)
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#define U300_TIMER_APP_EDDT_TIMER_ENABLE (0x00000000)
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/* Disable DD Timer 32bit (-/W) */
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#define U300_TIMER_APP_DDDT (0x0048)
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#define U300_TIMER_APP_DDDT_TIMER_DISABLE (0x00000000)
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/* DD Timer Mode Register 32bit (-/W) */
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#define U300_TIMER_APP_SDDTM (0x004c)
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#define U300_TIMER_APP_SDDTM_MODE_CONTINUOUS (0x00000000)
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#define U300_TIMER_APP_SDDTM_MODE_ONE_SHOT (0x00000001)
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/* DD Timer Status Register 32bit (R/-) */
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#define U300_TIMER_APP_DDTS (0x0050)
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#define U300_TIMER_APP_DDTS_TIMER_STATE_MASK (0x0000000F)
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#define U300_TIMER_APP_DDTS_TIMER_STATE_IDLE (0x00000001)
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#define U300_TIMER_APP_DDTS_TIMER_STATE_ACTIVE (0x00000002)
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#define U300_TIMER_APP_DDTS_ENABLE_IND (0x00000010)
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#define U300_TIMER_APP_DDTS_MODE_MASK (0x00000020)
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#define U300_TIMER_APP_DDTS_MODE_CONTINUOUS (0x00000000)
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#define U300_TIMER_APP_DDTS_MODE_ONE_SHOT (0x00000020)
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#define U300_TIMER_APP_DDTS_IRQ_ENABLED_IND (0x00000040)
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#define U300_TIMER_APP_DDTS_IRQ_PENDING_IND (0x00000080)
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/* DD Timer Current Count Register 32bit (R/-) */
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#define U300_TIMER_APP_DDTCC (0x0054)
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/* DD Timer Terminal Count Register 32bit (R/W) */
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#define U300_TIMER_APP_DDTTC (0x0058)
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/* DD Timer Interrupt Enable Register 32bit (-/W) */
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#define U300_TIMER_APP_DDTIE (0x005c)
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#define U300_TIMER_APP_DDTIE_IRQ_DISABLE (0x00000000)
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#define U300_TIMER_APP_DDTIE_IRQ_ENABLE (0x00000001)
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/* DD Timer Interrupt Acknowledge Register 32bit (-/W) */
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#define U300_TIMER_APP_DDTIA (0x0060)
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#define U300_TIMER_APP_DDTIA_IRQ_ACK (0x00000080)
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/* Reset GP1 Timer 32bit (-/W) */
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#define U300_TIMER_APP_RGPT1 (0x0080)
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#define U300_TIMER_APP_RGPT1_TIMER_RESET (0x00000000)
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/* Enable GP1 Timer 32bit (-/W) */
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#define U300_TIMER_APP_EGPT1 (0x0084)
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#define U300_TIMER_APP_EGPT1_TIMER_ENABLE (0x00000000)
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/* Disable GP1 Timer 32bit (-/W) */
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#define U300_TIMER_APP_DGPT1 (0x0088)
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#define U300_TIMER_APP_DGPT1_TIMER_DISABLE (0x00000000)
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/* GP1 Timer Mode Register 32bit (-/W) */
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#define U300_TIMER_APP_SGPT1M (0x008c)
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#define U300_TIMER_APP_SGPT1M_MODE_CONTINUOUS (0x00000000)
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#define U300_TIMER_APP_SGPT1M_MODE_ONE_SHOT (0x00000001)
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/* GP1 Timer Status Register 32bit (R/-) */
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#define U300_TIMER_APP_GPT1S (0x0090)
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#define U300_TIMER_APP_GPT1S_TIMER_STATE_MASK (0x0000000F)
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#define U300_TIMER_APP_GPT1S_TIMER_STATE_IDLE (0x00000001)
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#define U300_TIMER_APP_GPT1S_TIMER_STATE_ACTIVE (0x00000002)
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#define U300_TIMER_APP_GPT1S_ENABLE_IND (0x00000010)
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#define U300_TIMER_APP_GPT1S_MODE_MASK (0x00000020)
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#define U300_TIMER_APP_GPT1S_MODE_CONTINUOUS (0x00000000)
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#define U300_TIMER_APP_GPT1S_MODE_ONE_SHOT (0x00000020)
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#define U300_TIMER_APP_GPT1S_IRQ_ENABLED_IND (0x00000040)
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#define U300_TIMER_APP_GPT1S_IRQ_PENDING_IND (0x00000080)
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/* GP1 Timer Current Count Register 32bit (R/-) */
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#define U300_TIMER_APP_GPT1CC (0x0094)
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/* GP1 Timer Terminal Count Register 32bit (R/W) */
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#define U300_TIMER_APP_GPT1TC (0x0098)
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/* GP1 Timer Interrupt Enable Register 32bit (-/W) */
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#define U300_TIMER_APP_GPT1IE (0x009c)
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#define U300_TIMER_APP_GPT1IE_IRQ_DISABLE (0x00000000)
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#define U300_TIMER_APP_GPT1IE_IRQ_ENABLE (0x00000001)
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/* GP1 Timer Interrupt Acknowledge Register 32bit (-/W) */
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#define U300_TIMER_APP_GPT1IA (0x00a0)
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#define U300_TIMER_APP_GPT1IA_IRQ_ACK (0x00000080)
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/* Reset GP2 Timer 32bit (-/W) */
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#define U300_TIMER_APP_RGPT2 (0x00c0)
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#define U300_TIMER_APP_RGPT2_TIMER_RESET (0x00000000)
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/* Enable GP2 Timer 32bit (-/W) */
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#define U300_TIMER_APP_EGPT2 (0x00c4)
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#define U300_TIMER_APP_EGPT2_TIMER_ENABLE (0x00000000)
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/* Disable GP2 Timer 32bit (-/W) */
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#define U300_TIMER_APP_DGPT2 (0x00c8)
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#define U300_TIMER_APP_DGPT2_TIMER_DISABLE (0x00000000)
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/* GP2 Timer Mode Register 32bit (-/W) */
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#define U300_TIMER_APP_SGPT2M (0x00cc)
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#define U300_TIMER_APP_SGPT2M_MODE_CONTINUOUS (0x00000000)
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#define U300_TIMER_APP_SGPT2M_MODE_ONE_SHOT (0x00000001)
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/* GP2 Timer Status Register 32bit (R/-) */
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#define U300_TIMER_APP_GPT2S (0x00d0)
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#define U300_TIMER_APP_GPT2S_TIMER_STATE_MASK (0x0000000F)
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#define U300_TIMER_APP_GPT2S_TIMER_STATE_IDLE (0x00000001)
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#define U300_TIMER_APP_GPT2S_TIMER_STATE_ACTIVE (0x00000002)
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#define U300_TIMER_APP_GPT2S_ENABLE_IND (0x00000010)
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#define U300_TIMER_APP_GPT2S_MODE_MASK (0x00000020)
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#define U300_TIMER_APP_GPT2S_MODE_CONTINUOUS (0x00000000)
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#define U300_TIMER_APP_GPT2S_MODE_ONE_SHOT (0x00000020)
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#define U300_TIMER_APP_GPT2S_IRQ_ENABLED_IND (0x00000040)
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#define U300_TIMER_APP_GPT2S_IRQ_PENDING_IND (0x00000080)
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/* GP2 Timer Current Count Register 32bit (R/-) */
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#define U300_TIMER_APP_GPT2CC (0x00d4)
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/* GP2 Timer Terminal Count Register 32bit (R/W) */
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#define U300_TIMER_APP_GPT2TC (0x00d8)
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/* GP2 Timer Interrupt Enable Register 32bit (-/W) */
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#define U300_TIMER_APP_GPT2IE (0x00dc)
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#define U300_TIMER_APP_GPT2IE_IRQ_DISABLE (0x00000000)
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#define U300_TIMER_APP_GPT2IE_IRQ_ENABLE (0x00000001)
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/* GP2 Timer Interrupt Acknowledge Register 32bit (-/W) */
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#define U300_TIMER_APP_GPT2IA (0x00e0)
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#define U300_TIMER_APP_GPT2IA_IRQ_ACK (0x00000080)
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/* Clock request control register - all four timers */
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#define U300_TIMER_APP_CRC (0x100)
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#define U300_TIMER_APP_CRC_CLOCK_REQUEST_ENABLE (0x00000001)
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#define TICKS_PER_JIFFY ((CLOCK_TICK_RATE + (HZ/2)) / HZ)
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#define US_PER_TICK ((1000000 + (HZ/2)) / HZ)
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/*
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* The u300_set_mode() function is always called first, if we
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* have oneshot timer active, the oneshot scheduling function
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* u300_set_next_event() is called immediately after.
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*/
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static void u300_set_mode(enum clock_event_mode mode,
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struct clock_event_device *evt)
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{
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switch (mode) {
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case CLOCK_EVT_MODE_PERIODIC:
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/* Disable interrupts on GPT1 */
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writel(U300_TIMER_APP_GPT1IE_IRQ_DISABLE,
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U300_TIMER_APP_VBASE + U300_TIMER_APP_GPT1IE);
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/* Disable GP1 while we're reprogramming it. */
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writel(U300_TIMER_APP_DGPT1_TIMER_DISABLE,
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U300_TIMER_APP_VBASE + U300_TIMER_APP_DGPT1);
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/*
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* Set the periodic mode to a certain number of ticks per
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* jiffy.
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*/
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writel(TICKS_PER_JIFFY,
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U300_TIMER_APP_VBASE + U300_TIMER_APP_GPT1TC);
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/*
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* Set continuous mode, so the timer keeps triggering
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* interrupts.
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*/
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writel(U300_TIMER_APP_SGPT1M_MODE_CONTINUOUS,
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U300_TIMER_APP_VBASE + U300_TIMER_APP_SGPT1M);
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/* Enable timer interrupts */
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writel(U300_TIMER_APP_GPT1IE_IRQ_ENABLE,
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U300_TIMER_APP_VBASE + U300_TIMER_APP_GPT1IE);
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/* Then enable the OS timer again */
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writel(U300_TIMER_APP_EGPT1_TIMER_ENABLE,
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U300_TIMER_APP_VBASE + U300_TIMER_APP_EGPT1);
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break;
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case CLOCK_EVT_MODE_ONESHOT:
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/* Just break; here? */
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/*
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* The actual event will be programmed by the next event hook,
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* so we just set a dummy value somewhere at the end of the
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* universe here.
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*/
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/* Disable interrupts on GPT1 */
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writel(U300_TIMER_APP_GPT1IE_IRQ_DISABLE,
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U300_TIMER_APP_VBASE + U300_TIMER_APP_GPT1IE);
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/* Disable GP1 while we're reprogramming it. */
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writel(U300_TIMER_APP_DGPT1_TIMER_DISABLE,
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U300_TIMER_APP_VBASE + U300_TIMER_APP_DGPT1);
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/*
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* Expire far in the future, u300_set_next_event() will be
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* called soon...
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*/
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writel(0xFFFFFFFF, U300_TIMER_APP_VBASE + U300_TIMER_APP_GPT1TC);
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/* We run one shot per tick here! */
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writel(U300_TIMER_APP_SGPT1M_MODE_ONE_SHOT,
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U300_TIMER_APP_VBASE + U300_TIMER_APP_SGPT1M);
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/* Enable interrupts for this timer */
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writel(U300_TIMER_APP_GPT1IE_IRQ_ENABLE,
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U300_TIMER_APP_VBASE + U300_TIMER_APP_GPT1IE);
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/* Enable timer */
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writel(U300_TIMER_APP_EGPT1_TIMER_ENABLE,
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U300_TIMER_APP_VBASE + U300_TIMER_APP_EGPT1);
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break;
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case CLOCK_EVT_MODE_UNUSED:
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case CLOCK_EVT_MODE_SHUTDOWN:
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/* Disable interrupts on GP1 */
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writel(U300_TIMER_APP_GPT1IE_IRQ_DISABLE,
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U300_TIMER_APP_VBASE + U300_TIMER_APP_GPT1IE);
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/* Disable GP1 */
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writel(U300_TIMER_APP_DGPT1_TIMER_DISABLE,
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U300_TIMER_APP_VBASE + U300_TIMER_APP_DGPT1);
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break;
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case CLOCK_EVT_MODE_RESUME:
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/* Ignore this call */
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break;
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}
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}
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/*
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* The app timer in one shot mode obviously has to be reprogrammed
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* in EXACTLY this sequence to work properly. Do NOT try to e.g. replace
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* the interrupt disable + timer disable commands with a reset command,
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* it will fail miserably. Apparently (and I found this the hard way)
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* the timer is very sensitive to the instruction order, though you don't
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* get that impression from the data sheet.
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*/
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static int u300_set_next_event(unsigned long cycles,
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struct clock_event_device *evt)
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{
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/* Disable interrupts on GPT1 */
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writel(U300_TIMER_APP_GPT1IE_IRQ_DISABLE,
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U300_TIMER_APP_VBASE + U300_TIMER_APP_GPT1IE);
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/* Disable GP1 while we're reprogramming it. */
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writel(U300_TIMER_APP_DGPT1_TIMER_DISABLE,
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U300_TIMER_APP_VBASE + U300_TIMER_APP_DGPT1);
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/* Reset the General Purpose timer 1. */
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writel(U300_TIMER_APP_RGPT1_TIMER_RESET,
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U300_TIMER_APP_VBASE + U300_TIMER_APP_RGPT1);
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/* IRQ in n * cycles */
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writel(cycles, U300_TIMER_APP_VBASE + U300_TIMER_APP_GPT1TC);
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/*
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* We run one shot per tick here! (This is necessary to reconfigure,
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* the timer will tilt if you don't!)
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*/
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writel(U300_TIMER_APP_SGPT1M_MODE_ONE_SHOT,
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U300_TIMER_APP_VBASE + U300_TIMER_APP_SGPT1M);
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/* Enable timer interrupts */
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writel(U300_TIMER_APP_GPT1IE_IRQ_ENABLE,
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U300_TIMER_APP_VBASE + U300_TIMER_APP_GPT1IE);
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/* Then enable the OS timer again */
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writel(U300_TIMER_APP_EGPT1_TIMER_ENABLE,
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U300_TIMER_APP_VBASE + U300_TIMER_APP_EGPT1);
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return 0;
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}
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/* Use general purpose timer 1 as clock event */
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static struct clock_event_device clockevent_u300_1mhz = {
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.name = "GPT1",
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.rating = 300, /* Reasonably fast and accurate clock event */
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.features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
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/* 22 calculated using the algorithm in arch/mips/kernel/time.c */
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.shift = 22,
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.set_next_event = u300_set_next_event,
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.set_mode = u300_set_mode,
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};
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/* Clock event timer interrupt handler */
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static irqreturn_t u300_timer_interrupt(int irq, void *dev_id)
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{
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struct clock_event_device *evt = &clockevent_u300_1mhz;
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/* ACK/Clear timer IRQ for the APP GPT1 Timer */
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writel(U300_TIMER_APP_GPT1IA_IRQ_ACK,
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U300_TIMER_APP_VBASE + U300_TIMER_APP_GPT1IA);
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evt->event_handler(evt);
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return IRQ_HANDLED;
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}
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static struct irqaction u300_timer_irq = {
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.name = "U300 Timer Tick",
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.flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
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.handler = u300_timer_interrupt,
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};
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/* Use general purpose timer 2 as clock source */
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static cycle_t u300_get_cycles(struct clocksource *cs)
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{
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return (cycles_t) readl(U300_TIMER_APP_VBASE + U300_TIMER_APP_GPT2CC);
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}
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static struct clocksource clocksource_u300_1mhz = {
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.name = "GPT2",
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.rating = 300, /* Reasonably fast and accurate clock source */
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.read = u300_get_cycles,
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.mask = CLOCKSOURCE_MASK(32), /* 32 bits */
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/* 22 calculated using the algorithm in arch/mips/kernel/time.c */
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.shift = 22,
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.flags = CLOCK_SOURCE_IS_CONTINUOUS,
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};
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/*
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* This sets up the system timers, clock source and clock event.
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*/
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static void __init u300_timer_init(void)
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{
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u300_enable_timer_clock();
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/*
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* Disable the "OS" and "DD" timers - these are designed for Symbian!
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* Example usage in cnh1601578 cpu subsystem pd_timer_app.c
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*/
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writel(U300_TIMER_APP_CRC_CLOCK_REQUEST_ENABLE,
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U300_TIMER_APP_VBASE + U300_TIMER_APP_CRC);
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writel(U300_TIMER_APP_ROST_TIMER_RESET,
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U300_TIMER_APP_VBASE + U300_TIMER_APP_ROST);
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writel(U300_TIMER_APP_DOST_TIMER_DISABLE,
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U300_TIMER_APP_VBASE + U300_TIMER_APP_DOST);
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writel(U300_TIMER_APP_RDDT_TIMER_RESET,
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U300_TIMER_APP_VBASE + U300_TIMER_APP_RDDT);
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writel(U300_TIMER_APP_DDDT_TIMER_DISABLE,
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U300_TIMER_APP_VBASE + U300_TIMER_APP_DDDT);
|
|
|
|
/* Reset the General Purpose timer 1. */
|
|
writel(U300_TIMER_APP_RGPT1_TIMER_RESET,
|
|
U300_TIMER_APP_VBASE + U300_TIMER_APP_RGPT1);
|
|
|
|
/* Set up the IRQ handler */
|
|
setup_irq(IRQ_U300_TIMER_APP_GP1, &u300_timer_irq);
|
|
|
|
/* Reset the General Purpose timer 2 */
|
|
writel(U300_TIMER_APP_RGPT2_TIMER_RESET,
|
|
U300_TIMER_APP_VBASE + U300_TIMER_APP_RGPT2);
|
|
/* Set this timer to run around forever */
|
|
writel(0xFFFFFFFFU, U300_TIMER_APP_VBASE + U300_TIMER_APP_GPT2TC);
|
|
/* Set continuous mode so it wraps around */
|
|
writel(U300_TIMER_APP_SGPT2M_MODE_CONTINUOUS,
|
|
U300_TIMER_APP_VBASE + U300_TIMER_APP_SGPT2M);
|
|
/* Disable timer interrupts */
|
|
writel(U300_TIMER_APP_GPT2IE_IRQ_DISABLE,
|
|
U300_TIMER_APP_VBASE + U300_TIMER_APP_GPT2IE);
|
|
/* Then enable the GP2 timer to use as a free running us counter */
|
|
writel(U300_TIMER_APP_EGPT2_TIMER_ENABLE,
|
|
U300_TIMER_APP_VBASE + U300_TIMER_APP_EGPT2);
|
|
|
|
/* This is a pure microsecond clock source */
|
|
clocksource_u300_1mhz.mult =
|
|
clocksource_khz2mult(1000, clocksource_u300_1mhz.shift);
|
|
if (clocksource_register(&clocksource_u300_1mhz))
|
|
printk(KERN_ERR "timer: failed to initialize clock "
|
|
"source %s\n", clocksource_u300_1mhz.name);
|
|
|
|
clockevent_u300_1mhz.mult =
|
|
div_sc(1000000, NSEC_PER_SEC, clockevent_u300_1mhz.shift);
|
|
/* 32bit counter, so 32bits delta is max */
|
|
clockevent_u300_1mhz.max_delta_ns =
|
|
clockevent_delta2ns(0xffffffff, &clockevent_u300_1mhz);
|
|
/* This timer is slow enough to set for 1 cycle == 1 MHz */
|
|
clockevent_u300_1mhz.min_delta_ns =
|
|
clockevent_delta2ns(1, &clockevent_u300_1mhz);
|
|
clockevent_u300_1mhz.cpumask = cpumask_of(0);
|
|
clockevents_register_device(&clockevent_u300_1mhz);
|
|
/*
|
|
* TODO: init and register the rest of the timers too, they can be
|
|
* used by hrtimers!
|
|
*/
|
|
}
|
|
|
|
/*
|
|
* Very simple system timer that only register the clock event and
|
|
* clock source.
|
|
*/
|
|
struct sys_timer u300_timer = {
|
|
.init = u300_timer_init,
|
|
};
|