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author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/mips/gt64120/common/time.c | |
download | linux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.bz2 |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'arch/mips/gt64120/common/time.c')
-rw-r--r-- | arch/mips/gt64120/common/time.c | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/arch/mips/gt64120/common/time.c b/arch/mips/gt64120/common/time.c new file mode 100644 index 000000000000..2287b59536e5 --- /dev/null +++ b/arch/mips/gt64120/common/time.c @@ -0,0 +1,100 @@ +/* + * 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. + * + * Galileo Technology chip interrupt handler + */ +#include <linux/interrupt.h> +#include <linux/kernel.h> +#include <linux/config.h> +#include <linux/sched.h> +#include <linux/kernel_stat.h> +#include <asm/ptrace.h> +#include <asm/gt64120.h> + +/* + * These are interrupt handlers for the GT on-chip interrupts. They all come + * in to the MIPS on a single interrupt line, and have to be handled and ack'ed + * differently than other MIPS interrupts. + */ + +static void gt64120_irq(int irq, void *dev_id, struct pt_regs *regs) +{ + unsigned int irq_src, int_high_src, irq_src_mask, int_high_src_mask; + int handled = 0; + + irq_src = GT_READ(GT_INTRCAUSE_OFS); + irq_src_mask = GT_READ(GT_INTRMASK_OFS); + int_high_src = GT_READ(GT_HINTRCAUSE_OFS); + int_high_src_mask = GT_READ(GT_HINTRMASK_OFS); + irq_src = irq_src & irq_src_mask; + int_high_src = int_high_src & int_high_src_mask; + + if (irq_src & 0x00000800) { /* Check for timer interrupt */ + handled = 1; + irq_src &= ~0x00000800; + do_timer(regs); +#ifndef CONFIG_SMP + update_process_times(user_mode(regs)); +#endif + } + + GT_WRITE(GT_INTRCAUSE_OFS, 0); + GT_WRITE(GT_HINTRCAUSE_OFS, 0); +} + +/* + * Initializes timer using galileo's built in timer. + */ +#ifdef CONFIG_SYSCLK_100 +#define Sys_clock (100 * 1000000) // 100 MHz +#endif +#ifdef CONFIG_SYSCLK_83 +#define Sys_clock (83.333 * 1000000) // 83.333 MHz +#endif +#ifdef CONFIG_SYSCLK_75 +#define Sys_clock (75 * 1000000) // 75 MHz +#endif + +/* + * This will ignore the standard MIPS timer interrupt handler that is passed in + * as *irq (=irq0 in ../kernel/time.c). We will do our own timer interrupt + * handling. + */ +void gt64120_time_init(void) +{ + static struct irqaction timer; + + /* Disable timer first */ + GT_WRITE(GT_TC_CONTROL_OFS, 0); + /* Load timer value for 100 Hz */ + GT_WRITE(GT_TC3_OFS, Sys_clock / 100); + + /* + * Create the IRQ structure entry for the timer. Since we're too early + * in the boot process to use the "request_irq()" call, we'll hard-code + * the values to the correct interrupt line. + */ + timer.handler = gt64120_irq; + timer.flags = SA_SHIRQ | SA_INTERRUPT; + timer.name = "timer"; + timer.dev_id = NULL; + timer.next = NULL; + timer.mask = CPU_MASK_NONE; + irq_desc[GT_TIMER].action = &timer; + + enable_irq(GT_TIMER); + + /* Enable timer ints */ + GT_WRITE(GT_TC_CONTROL_OFS, 0xc0); + /* clear Cause register first */ + GT_WRITE(GT_INTRCAUSE_OFS, 0x0); + /* Unmask timer int */ + GT_WRITE(GT_INTRMASK_OFS, 0x800); + /* Clear High int register */ + GT_WRITE(GT_HINTRCAUSE_OFS, 0x0); + /* Mask All interrupts at High cause interrupt */ + GT_WRITE(GT_HINTRMASK_OFS, 0x0); +} |