diff options
Diffstat (limited to 'arch/mips/pnx8550/common/time.c')
| -rw-r--r-- | arch/mips/pnx8550/common/time.c | 151 |
1 files changed, 151 insertions, 0 deletions
diff --git a/arch/mips/pnx8550/common/time.c b/arch/mips/pnx8550/common/time.c new file mode 100644 index 0000000..8836c62 --- /dev/null +++ b/arch/mips/pnx8550/common/time.c @@ -0,0 +1,151 @@ +/* + * Copyright 2001, 2002, 2003 MontaVista Software Inc. + * Author: Jun Sun, jsun@mvista.com or jsun@junsun.net + * Copyright (C) 2007 Ralf Baechle (ralf@linux-mips.org) + * + * Common time service routines for MIPS machines. See + * Documents/MIPS/README.txt. + * + * 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. + */ +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/sched.h> +#include <linux/param.h> +#include <linux/time.h> +#include <linux/timer.h> +#include <linux/smp.h> +#include <linux/kernel_stat.h> +#include <linux/spinlock.h> +#include <linux/interrupt.h> + +#include <asm/bootinfo.h> +#include <asm/cpu.h> +#include <asm/time.h> +#include <asm/hardirq.h> +#include <asm/div64.h> +#include <asm/debug.h> + +#include <int.h> +#include <cm.h> + +static unsigned long cpj; + +static cycle_t hpt_read(struct clocksource *cs) +{ + return read_c0_count2(); +} + +static struct clocksource pnx_clocksource = { + .name = "pnx8xxx", + .rating = 200, + .read = hpt_read, + .flags = CLOCK_SOURCE_IS_CONTINUOUS, +}; + +static irqreturn_t pnx8xxx_timer_interrupt(int irq, void *dev_id) +{ + struct clock_event_device *c = dev_id; + + /* clear MATCH, signal the event */ + c->event_handler(c); + + return IRQ_HANDLED; +} + +static struct irqaction pnx8xxx_timer_irq = { + .handler = pnx8xxx_timer_interrupt, + .flags = IRQF_DISABLED | IRQF_PERCPU | IRQF_TIMER, + .name = "pnx8xxx_timer", +}; + +static irqreturn_t monotonic_interrupt(int irq, void *dev_id) +{ + /* Timer 2 clear interrupt */ + write_c0_compare2(-1); + return IRQ_HANDLED; +} + +static struct irqaction monotonic_irqaction = { + .handler = monotonic_interrupt, + .flags = IRQF_DISABLED | IRQF_TIMER, + .name = "Monotonic timer", +}; + +static int pnx8xxx_set_next_event(unsigned long delta, + struct clock_event_device *evt) +{ + write_c0_compare(delta); + return 0; +} + +static struct clock_event_device pnx8xxx_clockevent = { + .name = "pnx8xxx_clockevent", + .features = CLOCK_EVT_FEAT_ONESHOT, + .set_next_event = pnx8xxx_set_next_event, +}; + +static inline void timer_ack(void) +{ + write_c0_compare(cpj); +} + +__init void plat_time_init(void) +{ + unsigned int configPR; + unsigned int n; + unsigned int m; + unsigned int p; + unsigned int pow2p; + + pnx8xxx_clockevent.cpumask = cpu_none_mask; + clockevents_register_device(&pnx8xxx_clockevent); + clocksource_register(&pnx_clocksource); + + /* Timer 1 start */ + configPR = read_c0_config7(); + configPR &= ~0x00000008; + write_c0_config7(configPR); + + /* Timer 2 start */ + configPR = read_c0_config7(); + configPR &= ~0x00000010; + write_c0_config7(configPR); + + /* Timer 3 stop */ + configPR = read_c0_config7(); + configPR |= 0x00000020; + write_c0_config7(configPR); + + + /* PLL0 sets MIPS clock (PLL1 <=> TM1, PLL6 <=> TM2, PLL5 <=> mem) */ + /* (but only if CLK_MIPS_CTL select value [bits 3:1] is 1: FIXME) */ + + n = (PNX8550_CM_PLL0_CTL & PNX8550_CM_PLL_N_MASK) >> 16; + m = (PNX8550_CM_PLL0_CTL & PNX8550_CM_PLL_M_MASK) >> 8; + p = (PNX8550_CM_PLL0_CTL & PNX8550_CM_PLL_P_MASK) >> 2; + pow2p = (1 << p); + + db_assert(m != 0 && pow2p != 0); + + /* + * Compute the frequency as in the PNX8550 User Manual 1.0, p.186 + * (a.k.a. 8-10). Divide by HZ for a timer offset that results in + * HZ timer interrupts per second. + */ + mips_hpt_frequency = 27UL * ((1000000UL * n)/(m * pow2p)); + cpj = DIV_ROUND_CLOSEST(mips_hpt_frequency, HZ); + write_c0_count(0); + timer_ack(); + + /* Setup Timer 2 */ + write_c0_count2(0); + write_c0_compare2(0xffffffff); + + setup_irq(PNX8550_INT_TIMER1, &pnx8xxx_timer_irq); + setup_irq(PNX8550_INT_TIMER2, &monotonic_irqaction); +} |