diff options
Diffstat (limited to 'arch/mips/sibyte/bcm1480/time.c')
| -rw-r--r-- | arch/mips/sibyte/bcm1480/time.c | 138 |
1 files changed, 138 insertions, 0 deletions
diff --git a/arch/mips/sibyte/bcm1480/time.c b/arch/mips/sibyte/bcm1480/time.c new file mode 100644 index 000000000000..e545752695a1 --- /dev/null +++ b/arch/mips/sibyte/bcm1480/time.c @@ -0,0 +1,138 @@ +/* + * Copyright (C) 2000,2001,2004 Broadcom Corporation + * + * 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. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + */ + +/* + * These are routines to set up and handle interrupts from the + * bcm1480 general purpose timer 0. We're using the timer as a + * system clock, so we set it up to run at 100 Hz. On every + * interrupt, we update our idea of what the time of day is, + * then call do_timer() in the architecture-independent kernel + * code to do general bookkeeping (e.g. update jiffies, run + * bottom halves, etc.) + */ +#include <linux/config.h> +#include <linux/interrupt.h> +#include <linux/sched.h> +#include <linux/spinlock.h> +#include <linux/kernel_stat.h> + +#include <asm/irq.h> +#include <asm/ptrace.h> +#include <asm/addrspace.h> +#include <asm/time.h> +#include <asm/io.h> + +#include <asm/sibyte/bcm1480_regs.h> +#include <asm/sibyte/sb1250_regs.h> +#include <asm/sibyte/bcm1480_int.h> +#include <asm/sibyte/bcm1480_scd.h> + +#include <asm/sibyte/sb1250.h> + + +#define IMR_IP2_VAL K_BCM1480_INT_MAP_I0 +#define IMR_IP3_VAL K_BCM1480_INT_MAP_I1 +#define IMR_IP4_VAL K_BCM1480_INT_MAP_I2 + +extern int bcm1480_steal_irq(int irq); + +void bcm1480_time_init(void) +{ + int cpu = smp_processor_id(); + int irq = K_BCM1480_INT_TIMER_0+cpu; + + /* Only have 4 general purpose timers */ + if (cpu > 3) { + BUG(); + } + + if (!cpu) { + /* Use our own gettimeoffset() routine */ + do_gettimeoffset = bcm1480_gettimeoffset; + } + + bcm1480_mask_irq(cpu, irq); + + /* Map the timer interrupt to ip[4] of this cpu */ + __raw_writeq(IMR_IP4_VAL, IOADDR(A_BCM1480_IMR_REGISTER(cpu, R_BCM1480_IMR_INTERRUPT_MAP_BASE_H) + + (irq<<3))); + + /* the general purpose timer ticks at 1 Mhz independent of the rest of the system */ + /* Disable the timer and set up the count */ + __raw_writeq(0, IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG))); + __raw_writeq( +#ifndef CONFIG_SIMULATION + 1000000/HZ +#else + 50000/HZ +#endif + , IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_INIT))); + + /* Set the timer running */ + __raw_writeq(M_SCD_TIMER_ENABLE|M_SCD_TIMER_MODE_CONTINUOUS, + IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG))); + + bcm1480_unmask_irq(cpu, irq); + bcm1480_steal_irq(irq); + /* + * This interrupt is "special" in that it doesn't use the request_irq + * way to hook the irq line. The timer interrupt is initialized early + * enough to make this a major pain, and it's also firing enough to + * warrant a bit of special case code. bcm1480_timer_interrupt is + * called directly from irq_handler.S when IP[4] is set during an + * interrupt + */ +} + +#include <asm/sibyte/sb1250.h> + +void bcm1480_timer_interrupt(struct pt_regs *regs) +{ + int cpu = smp_processor_id(); + int irq = K_BCM1480_INT_TIMER_0+cpu; + + /* Reset the timer */ + __raw_writeq(M_SCD_TIMER_ENABLE|M_SCD_TIMER_MODE_CONTINUOUS, + IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG))); + + /* + * CPU 0 handles the global timer interrupt job + */ + if (cpu == 0) { + ll_timer_interrupt(irq, regs); + } + + /* + * every CPU should do profiling and process accouting + */ + ll_local_timer_interrupt(irq, regs); +} + +/* + * We use our own do_gettimeoffset() instead of the generic one, + * because the generic one does not work for SMP case. + * In addition, since we use general timer 0 for system time, + * we can get accurate intra-jiffy offset without calibration. + */ +unsigned long bcm1480_gettimeoffset(void) +{ + unsigned long count = + __raw_readq(IOADDR(A_SCD_TIMER_REGISTER(0, R_SCD_TIMER_CNT))); + + return 1000000/HZ - count; +} |