462 lines
16 KiB
C
462 lines
16 KiB
C
/*
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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 <linux/clk.h>
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#include <linux/err.h>
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#include <linux/irq.h>
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#include <linux/delay.h>
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#include <linux/of_address.h>
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#include <linux/of_irq.h>
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#include <linux/sched_clock.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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/*
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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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static void __iomem *u300_timer_base;
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struct u300_clockevent_data {
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struct clock_event_device cevd;
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unsigned ticks_per_jiffy;
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};
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static int u300_shutdown(struct clock_event_device *evt)
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{
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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_base + 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_base + U300_TIMER_APP_DGPT1);
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return 0;
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}
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/*
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* If we 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 int u300_set_oneshot(struct clock_event_device *evt)
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{
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/* Just return; 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_base + 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_base + 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_base + 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_base + 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_base + 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_base + U300_TIMER_APP_EGPT1);
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return 0;
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}
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static int u300_set_periodic(struct clock_event_device *evt)
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{
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struct u300_clockevent_data *cevdata =
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container_of(evt, struct u300_clockevent_data, cevd);
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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_base + 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_base + 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(cevdata->ticks_per_jiffy,
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u300_timer_base + 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_base + 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_base + 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_base + U300_TIMER_APP_EGPT1);
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return 0;
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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_base + 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_base + 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_base + U300_TIMER_APP_RGPT1);
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/* IRQ in n * cycles */
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writel(cycles, u300_timer_base + 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_base + 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_base + 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_base + U300_TIMER_APP_EGPT1);
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return 0;
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}
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static struct u300_clockevent_data u300_clockevent_data = {
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/* Use general purpose timer 1 as clock event */
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.cevd = {
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.name = "GPT1",
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/* Reasonably fast and accurate clock event */
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.rating = 300,
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.features = CLOCK_EVT_FEAT_PERIODIC |
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CLOCK_EVT_FEAT_ONESHOT,
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.set_next_event = u300_set_next_event,
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.set_state_shutdown = u300_shutdown,
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.set_state_periodic = u300_set_periodic,
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.set_state_oneshot = u300_set_oneshot,
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},
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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 = &u300_clockevent_data.cevd;
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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_base + 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_TIMER | IRQF_IRQPOLL,
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.handler = u300_timer_interrupt,
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};
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/*
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* Override the global weak sched_clock symbol with this
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* local implementation which uses the clocksource to get some
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* better resolution when scheduling the kernel. We accept that
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* this wraps around for now, since it is just a relative time
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* stamp. (Inspired by OMAP implementation.)
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*/
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static u64 notrace u300_read_sched_clock(void)
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{
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return readl(u300_timer_base + U300_TIMER_APP_GPT2CC);
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}
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static unsigned long u300_read_current_timer(void)
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{
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return readl(u300_timer_base + U300_TIMER_APP_GPT2CC);
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}
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static struct delay_timer u300_delay_timer;
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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 int __init u300_timer_init_of(struct device_node *np)
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{
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unsigned int irq;
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struct clk *clk;
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unsigned long rate;
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int ret;
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u300_timer_base = of_iomap(np, 0);
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if (!u300_timer_base) {
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pr_err("could not ioremap system timer\n");
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return -ENXIO;
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}
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/* Get the IRQ for the GP1 timer */
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irq = irq_of_parse_and_map(np, 2);
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if (!irq) {
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pr_err("no IRQ for system timer\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
pr_info("U300 GP1 timer @ base: %p, IRQ: %u\n", u300_timer_base, irq);
|
|
|
|
/* Clock the interrupt controller */
|
|
clk = of_clk_get(np, 0);
|
|
if (IS_ERR(clk))
|
|
return PTR_ERR(clk);
|
|
|
|
ret = clk_prepare_enable(clk);
|
|
if (ret)
|
|
return ret;
|
|
|
|
rate = clk_get_rate(clk);
|
|
|
|
u300_clockevent_data.ticks_per_jiffy = DIV_ROUND_CLOSEST(rate, HZ);
|
|
|
|
sched_clock_register(u300_read_sched_clock, 32, rate);
|
|
|
|
u300_delay_timer.read_current_timer = &u300_read_current_timer;
|
|
u300_delay_timer.freq = rate;
|
|
register_current_timer_delay(&u300_delay_timer);
|
|
|
|
/*
|
|
* Disable the "OS" and "DD" timers - these are designed for Symbian!
|
|
* Example usage in cnh1601578 cpu subsystem pd_timer_app.c
|
|
*/
|
|
writel(U300_TIMER_APP_CRC_CLOCK_REQUEST_ENABLE,
|
|
u300_timer_base + U300_TIMER_APP_CRC);
|
|
writel(U300_TIMER_APP_ROST_TIMER_RESET,
|
|
u300_timer_base + U300_TIMER_APP_ROST);
|
|
writel(U300_TIMER_APP_DOST_TIMER_DISABLE,
|
|
u300_timer_base + U300_TIMER_APP_DOST);
|
|
writel(U300_TIMER_APP_RDDT_TIMER_RESET,
|
|
u300_timer_base + U300_TIMER_APP_RDDT);
|
|
writel(U300_TIMER_APP_DDDT_TIMER_DISABLE,
|
|
u300_timer_base + U300_TIMER_APP_DDDT);
|
|
|
|
/* Reset the General Purpose timer 1. */
|
|
writel(U300_TIMER_APP_RGPT1_TIMER_RESET,
|
|
u300_timer_base + U300_TIMER_APP_RGPT1);
|
|
|
|
/* Set up the IRQ handler */
|
|
ret = setup_irq(irq, &u300_timer_irq);
|
|
if (ret)
|
|
return ret;
|
|
|
|
/* Reset the General Purpose timer 2 */
|
|
writel(U300_TIMER_APP_RGPT2_TIMER_RESET,
|
|
u300_timer_base + U300_TIMER_APP_RGPT2);
|
|
/* Set this timer to run around forever */
|
|
writel(0xFFFFFFFFU, u300_timer_base + U300_TIMER_APP_GPT2TC);
|
|
/* Set continuous mode so it wraps around */
|
|
writel(U300_TIMER_APP_SGPT2M_MODE_CONTINUOUS,
|
|
u300_timer_base + U300_TIMER_APP_SGPT2M);
|
|
/* Disable timer interrupts */
|
|
writel(U300_TIMER_APP_GPT2IE_IRQ_DISABLE,
|
|
u300_timer_base + 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_base + U300_TIMER_APP_EGPT2);
|
|
|
|
/* Use general purpose timer 2 as clock source */
|
|
ret = clocksource_mmio_init(u300_timer_base + U300_TIMER_APP_GPT2CC,
|
|
"GPT2", rate, 300, 32, clocksource_mmio_readl_up);
|
|
if (ret) {
|
|
pr_err("timer: failed to initialize U300 clock source\n");
|
|
return ret;
|
|
}
|
|
|
|
/* Configure and register the clockevent */
|
|
clockevents_config_and_register(&u300_clockevent_data.cevd, rate,
|
|
1, 0xffffffff);
|
|
|
|
/*
|
|
* TODO: init and register the rest of the timers too, they can be
|
|
* used by hrtimers!
|
|
*/
|
|
return 0;
|
|
}
|
|
|
|
CLOCKSOURCE_OF_DECLARE(u300_timer, "stericsson,u300-apptimer",
|
|
u300_timer_init_of);
|