diff options
Diffstat (limited to 'arch/mips/gt64120/wrppmc/time.c')
| -rw-r--r-- | arch/mips/gt64120/wrppmc/time.c | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/arch/mips/gt64120/wrppmc/time.c b/arch/mips/gt64120/wrppmc/time.c new file mode 100644 index 00000000000..175d22adb45 --- /dev/null +++ b/arch/mips/gt64120/wrppmc/time.c @@ -0,0 +1,57 @@ +/* + * time.c: MIPS CPU Count/Compare timer hookup + * + * Author: Mark.Zhan, <rongkai.zhan@windriver.com> + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 1996, 1997, 2004 by Ralf Baechle (ralf@linux-mips.org) + * Copyright (C) 2006, Wind River System Inc. + */ +#include <linux/config.h> +#include <linux/init.h> +#include <linux/string.h> +#include <linux/kernel.h> +#include <linux/param.h> /* for HZ */ +#include <linux/irq.h> +#include <linux/timex.h> +#include <linux/interrupt.h> + +#include <asm/reboot.h> +#include <asm/time.h> +#include <asm/io.h> +#include <asm/bootinfo.h> +#include <asm/gt64120.h> + +#define WRPPMC_CPU_CLK_FREQ 40000000 /* 40MHZ */ + +void __init wrppmc_timer_setup(struct irqaction *irq) +{ + /* Install ISR for timer interrupt */ + setup_irq(WRPPMC_MIPS_TIMER_IRQ, irq); + + /* to generate the first timer interrupt */ + write_c0_compare(mips_hpt_frequency/HZ); + write_c0_count(0); +} + +/* + * Estimate CPU frequency. Sets mips_hpt_frequency as a side-effect + * + * NOTE: We disable all GT64120 timers, and use MIPS processor internal + * timer as the source of kernel clock tick. + */ +void __init wrppmc_time_init(void) +{ + /* Disable GT64120 timers */ + GT_WRITE(GT_TC_CONTROL_OFS, 0x00); + GT_WRITE(GT_TC0_OFS, 0x00); + GT_WRITE(GT_TC1_OFS, 0x00); + GT_WRITE(GT_TC2_OFS, 0x00); + GT_WRITE(GT_TC3_OFS, 0x00); + + /* Use MIPS compare/count internal timer */ + mips_hpt_frequency = WRPPMC_CPU_CLK_FREQ; +} |