1dbae815a7
Patch from Tony Lindgren This patch adds support for omap24xx series of processors. The files live in arch/arm/mach-omap2, and share common files with omap15xx and omap16xx processors in arch/arm/plat-omap. Omap24xx support was originally added for 2.6.9 by TI. This code was then improved and integrated to share common code with omap15xx and omap16xx processors by various omap developers, such as Paul Mundt, Juha Yrjola, Imre Deak, Tony Lindgren, Richard Woodruff, Nishant Menon, Komal Shah et al. Signed-off-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
126 lines
3 KiB
C
126 lines
3 KiB
C
/*
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* linux/arch/arm/mach-omap2/timer-gp.c
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*
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* OMAP2 GP timer support.
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*
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* Copyright (C) 2005 Nokia Corporation
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* Author: Paul Mundt <paul.mundt@nokia.com>
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* Juha Yrjölä <juha.yrjola@nokia.com>
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*
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* Some parts based off of TI's 24xx code:
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*
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* Copyright (C) 2004 Texas Instruments, Inc.
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*
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* Roughly modelled after the OMAP1 MPU timer code.
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*/
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#include <linux/init.h>
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#include <linux/time.h>
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#include <linux/interrupt.h>
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#include <linux/err.h>
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#include <asm/mach/time.h>
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#include <asm/delay.h>
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#include <asm/io.h>
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#include <asm/hardware/clock.h>
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#define OMAP2_GP_TIMER1_BASE 0x48028000
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#define OMAP2_GP_TIMER2_BASE 0x4802a000
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#define OMAP2_GP_TIMER3_BASE 0x48078000
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#define OMAP2_GP_TIMER4_BASE 0x4807a000
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#define GP_TIMER_TIDR 0x00
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#define GP_TIMER_TISR 0x18
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#define GP_TIMER_TIER 0x1c
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#define GP_TIMER_TCLR 0x24
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#define GP_TIMER_TCRR 0x28
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#define GP_TIMER_TLDR 0x2c
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#define GP_TIMER_TSICR 0x40
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#define OS_TIMER_NR 1 /* GP timer 2 */
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static unsigned long timer_base[] = {
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IO_ADDRESS(OMAP2_GP_TIMER1_BASE),
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IO_ADDRESS(OMAP2_GP_TIMER2_BASE),
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IO_ADDRESS(OMAP2_GP_TIMER3_BASE),
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IO_ADDRESS(OMAP2_GP_TIMER4_BASE),
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};
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static inline unsigned int timer_read_reg(int nr, unsigned int reg)
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{
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return __raw_readl(timer_base[nr] + reg);
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}
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static inline void timer_write_reg(int nr, unsigned int reg, unsigned int val)
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{
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__raw_writel(val, timer_base[nr] + reg);
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}
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/* Note that we always enable the clock prescale divider bit */
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static inline void omap2_gp_timer_start(int nr, unsigned long load_val)
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{
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unsigned int tmp;
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tmp = 0xffffffff - load_val;
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timer_write_reg(nr, GP_TIMER_TLDR, tmp);
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timer_write_reg(nr, GP_TIMER_TCRR, tmp);
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timer_write_reg(nr, GP_TIMER_TIER, 1 << 1);
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timer_write_reg(nr, GP_TIMER_TCLR, (1 << 5) | (1 << 1) | 1);
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}
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static irqreturn_t omap2_gp_timer_interrupt(int irq, void *dev_id,
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struct pt_regs *regs)
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{
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write_seqlock(&xtime_lock);
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timer_write_reg(OS_TIMER_NR, GP_TIMER_TISR, 1 << 1);
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timer_tick(regs);
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write_sequnlock(&xtime_lock);
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return IRQ_HANDLED;
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}
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static struct irqaction omap2_gp_timer_irq = {
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.name = "gp timer",
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.flags = SA_INTERRUPT,
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.handler = omap2_gp_timer_interrupt,
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};
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static void __init omap2_gp_timer_init(void)
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{
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struct clk * sys_ck;
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u32 tick_period = 120000;
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u32 l;
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/* Reset clock and prescale value */
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timer_write_reg(OS_TIMER_NR, GP_TIMER_TCLR, 0);
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sys_ck = clk_get(NULL, "sys_ck");
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if (IS_ERR(sys_ck))
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printk(KERN_ERR "Could not get sys_ck\n");
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else {
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clk_use(sys_ck);
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tick_period = clk_get_rate(sys_ck) / 100;
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clk_put(sys_ck);
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}
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tick_period /= 2; /* Minimum prescale divider is 2 */
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tick_period -= 1;
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l = timer_read_reg(OS_TIMER_NR, GP_TIMER_TIDR);
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printk(KERN_INFO "OMAP2 GP timer (HW version %d.%d)\n",
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(l >> 4) & 0x0f, l & 0x0f);
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setup_irq(38, &omap2_gp_timer_irq);
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omap2_gp_timer_start(OS_TIMER_NR, tick_period);
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}
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struct sys_timer omap_timer = {
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.init = omap2_gp_timer_init,
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};
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