diff options
Diffstat (limited to 'target/linux/olpc/files/arch/i386/kernel/mfgpt.c')
| -rw-r--r-- | target/linux/olpc/files/arch/i386/kernel/mfgpt.c | 354 |
1 files changed, 0 insertions, 354 deletions
diff --git a/target/linux/olpc/files/arch/i386/kernel/mfgpt.c b/target/linux/olpc/files/arch/i386/kernel/mfgpt.c deleted file mode 100644 index 2e62a41e7..000000000 --- a/target/linux/olpc/files/arch/i386/kernel/mfgpt.c +++ /dev/null @@ -1,354 +0,0 @@ -/* Driver/API for AMD Geode Multi-Function General Purpose Timers (MFGPT) - * - * Copyright (C) 2006, Advanced Micro Devices, Inc. - * - * 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. - */ - -/* The MFPGT timers on the CS5536 provide us with suitable timers to use - * as clock event sources - not as good as a HPET or APIC, but certainly - * better then the PIT. This isn't a general purpose MFGPT driver, but - * a simplified one designed specifically to act as a clock event source. - * For full details about the MFGPT, please consult the CS5536 data sheet. -*/ - -/* We are using the 32Khz input clock - its the only one that has the - * ranges we find desirable. The following table lists the suitable - * divisors and the associated hz, minimum interval - * and the maximum interval: - - Divisor Hz Min Delta (S) Max Delta (S) - 1 32000 .0005 2.048 - 2 16000 .001 4.096 - 4 8000 .002 8.192 - 8 4000 .004 16.384 - 16 2000 .008 32.768 - 32 1000 .016 65.536 - 64 500 .032 131.072 - 128 250 .064 262.144 - 256 125 .128 524.288 -*/ - -#include <linux/kernel.h> -#include <linux/interrupt.h> -#include <linux/module.h> -#include <linux/clocksource.h> -#include <linux/clockchips.h> -#include <asm/geode.h> - -#include "do_timer.h" - -#define MFGPT_MAX_TIMERS 8 - -#define F_AVAIL 0x01 - -static struct mfgpt_timer_t { - int flags; - struct module *owner; -} mfgpt_timers[MFGPT_MAX_TIMERS]; - -/* Selected from the table above */ - -#define MFGPT_DIVISOR 16 -#define MFGPT_SCALE 4 /* divisor = 2^(scale) */ -#define MFGPT_HZ (32000 / MFGPT_DIVISOR) -#define MFGPT_PERIODIC (MFGPT_HZ / HZ) - -#ifdef CONFIG_GEODE_MFGPT_TIMER -static int __init mfgpt_timer_setup(void); -#else -#define mfgpt_timer_setup() (0) -#endif - -/* Allow for disabling of MFGPTs */ -static int disable = 0; -static int __init mfgpt_disable(char *s) -{ - disable = 1; - return 1; -} -__setup("nomfgpt", mfgpt_disable); - -/* - * Check whether any MFGPTs are available for the kernel to use. In most - * cases, firmware that uses AMD's VSA code will claim all timers during - * bootup; we certainly don't want to take them if they're already in use. - * In other cases (such as with VSAless OpenFirmware), the system firmware - * leaves timers available for us to use. - */ -int __init geode_mfgpt_detect(void) -{ - int count = 0, i; - u16 val; - - if (disable) { - printk(KERN_INFO "geode-mfgpt: Skipping MFGPT setup\n"); - return 0; - } - - for (i = 0; i < MFGPT_MAX_TIMERS; i++) { - val = geode_mfgpt_read(i, MFGPT_REG_SETUP); - if (!(val & MFGPT_SETUP_SETUP)) { - mfgpt_timers[i].flags = F_AVAIL; - count++; - } - } - - /* set up clock event device, if desired */ - i = mfgpt_timer_setup(); - - return count; -} - -int geode_mfgpt_toggle_event(int timer, int cmp, int event, int enable) -{ - u32 msr, mask, value, dummy; - int shift = (cmp == MFGPT_CMP1) ? 0 : 8; - - if (timer < 0 || timer >= MFGPT_MAX_TIMERS) - return -EIO; - - /* - * The register maps for these are described in sections 6.17.1.x of - * the AMD Geode CS5536 Companion Device Data Book. - */ - switch(event) { - case MFGPT_EVENT_RESET: - /* XXX: According to the docs, we cannot reset timers above - * 6; that is, resets for 7 and 8 will be ignored. Is this - * a problem? */ - msr = MFGPT_NR_MSR; - mask = 1 << (timer + 24); - break; - - case MFGPT_EVENT_NMI: - msr = MFGPT_NR_MSR; - mask = 1 << (timer + shift); - break; - - case MFGPT_EVENT_IRQ: - msr = MFGPT_IRQ_MSR; - mask = 1 << (timer + shift); - break; - - default: - return -EIO; - } - - rdmsr(msr, value, dummy); - - if (enable) - value |= mask; - else - value &= ~mask; - - wrmsr(msr, value, dummy); - return 0; -} -EXPORT_SYMBOL(geode_mfgpt_toggle_event); - -int geode_mfgpt_set_irq(int timer, int cmp, int irq, int enable) -{ - u32 val, dummy; - int offset; - - if (timer < 0 || timer >= MFGPT_MAX_TIMERS) - return -EIO; - - if (geode_mfgpt_toggle_event(timer, cmp, MFGPT_EVENT_IRQ, enable)) - return -EIO; - - rdmsr(0x51400022, val, dummy); - - offset = (timer % 4) * 4; - - val &= ~((0xF << offset) | (0xF << (offset + 16))); - - if (enable) { - val |= (irq & 0x0F) << (offset); - val |= (irq & 0x0F) << (offset + 16); - } - - wrmsr(0x51400022, val, dummy); - return 0; -} -EXPORT_SYMBOL(geode_mfgpt_set_irq); - -static int mfgpt_get(int timer, struct module *owner) -{ - mfgpt_timers[timer].flags &= ~F_AVAIL; - mfgpt_timers[timer].owner = owner; - printk(KERN_INFO "geode-mfgpt: Registered timer %d\n", timer); - return timer; -} - -int geode_mfgpt_alloc_timer(int timer, int domain, struct module *owner) -{ - int i; - - if (!geode_get_dev_base(GEODE_DEV_MFGPT)) - return -ENODEV; - if (timer >= MFGPT_MAX_TIMERS) - return -EIO; - - if (timer < 0) { - /* Try to find an available timer */ - for (i = 0; i < MFGPT_MAX_TIMERS; i++) { - if (mfgpt_timers[i].flags & F_AVAIL) - return mfgpt_get(i, owner); - - if (i == 5 && domain == MFGPT_DOMAIN_WORKING) - break; - } - } - else { - /* If they requested a specific timer, try to honor that */ - if (mfgpt_timers[timer].flags & F_AVAIL) - return mfgpt_get(timer, owner); - } - - /* No timers available - too bad */ - return -1; -} -EXPORT_SYMBOL(geode_mfgpt_alloc_timer); - -#ifdef CONFIG_GEODE_MFGPT_TIMER - -static unsigned int mfgpt_tick_mode = CLOCK_EVT_MODE_SHUTDOWN; -static u16 mfgpt_event_clock; - -static int irq = 7; -static int __init mfgpt_setup(char *str) -{ - get_option(&str, &irq); - return 1; -} -__setup("mfgpt_irq=", mfgpt_setup); - -static inline void mfgpt_disable_timer(u16 clock) -{ - u16 val = geode_mfgpt_read(clock, MFGPT_REG_SETUP); - geode_mfgpt_write(clock, MFGPT_REG_SETUP, val & ~MFGPT_SETUP_CNTEN); -} - -static int mfgpt_next_event(unsigned long, struct clock_event_device *); -static void mfgpt_set_mode(enum clock_event_mode, struct clock_event_device *); - -static struct clock_event_device mfgpt_clockevent = { - .name = "mfgpt-timer", - .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT, - .set_mode = mfgpt_set_mode, - .set_next_event = mfgpt_next_event, - .rating = 250, - .cpumask = CPU_MASK_ALL, - .shift = 32 -}; - -static inline void mfgpt_start_timer(u16 clock, u16 delta) -{ - geode_mfgpt_write(mfgpt_event_clock, MFGPT_REG_CMP2, (u16) delta); - geode_mfgpt_write(mfgpt_event_clock, MFGPT_REG_COUNTER, 0); - - geode_mfgpt_write(mfgpt_event_clock, MFGPT_REG_SETUP, - MFGPT_SETUP_CNTEN | MFGPT_SETUP_CMP2); -} - -static void mfgpt_set_mode(enum clock_event_mode mode, - struct clock_event_device *evt) -{ - mfgpt_disable_timer(mfgpt_event_clock); - - if (mode == CLOCK_EVT_MODE_PERIODIC) - mfgpt_start_timer(mfgpt_event_clock, MFGPT_PERIODIC); - - mfgpt_tick_mode = mode; -} - -static int mfgpt_next_event(unsigned long delta, struct clock_event_device *evt) -{ - mfgpt_start_timer(mfgpt_event_clock, delta); - return 0; -} - -/* Assume (foolishly?), that this interrupt was due to our tick */ - -static irqreturn_t mfgpt_tick(int irq, void *dev_id) -{ - if (mfgpt_tick_mode == CLOCK_EVT_MODE_SHUTDOWN) - return IRQ_HANDLED; - - /* Turn off the clock */ - mfgpt_disable_timer(mfgpt_event_clock); - - /* Clear the counter */ - geode_mfgpt_write(mfgpt_event_clock, MFGPT_REG_COUNTER, 0); - - /* Restart the clock in periodic mode */ - - if (mfgpt_tick_mode == CLOCK_EVT_MODE_PERIODIC) { - geode_mfgpt_write(mfgpt_event_clock, MFGPT_REG_SETUP, - MFGPT_SETUP_CNTEN | MFGPT_SETUP_CMP2); - } - - mfgpt_clockevent.event_handler(&mfgpt_clockevent); - return IRQ_HANDLED; -} - -static struct irqaction mfgptirq = { - .handler = mfgpt_tick, - .flags = IRQF_DISABLED | IRQF_NOBALANCING, - .mask = CPU_MASK_NONE, - .name = "mfgpt-timer" -}; - -static int __init mfgpt_timer_setup(void) -{ - int timer, ret; - u16 val; - - timer = geode_mfgpt_alloc_timer(MFGPT_TIMER_ANY, MFGPT_DOMAIN_WORKING, THIS_MODULE); - if (timer < 0) { - printk(KERN_ERR "mfgpt-timer: Could not allocate a MFPGT timer\n"); - return -ENODEV; - } - - mfgpt_event_clock = timer; - /* Set the clock scale and enable the event mode for CMP2 */ - val = MFGPT_SCALE | (3 << 8); - - geode_mfgpt_write(mfgpt_event_clock, MFGPT_REG_SETUP, val); - - /* Set up the IRQ on the MFGPT side */ - if (geode_mfgpt_setup_irq(mfgpt_event_clock, MFGPT_CMP2, irq)) { - printk(KERN_ERR "mfgpt-timer: Could not set up IRQ %d\n", irq); - return -EIO; - } - - /* And register it with the kernel */ - ret = setup_irq(irq, &mfgptirq); - - if (ret) { - printk(KERN_ERR "mfgpt-timer: Unable to set up the interrupt.\n"); - goto err; - } - - /* Set up the clock event */ - mfgpt_clockevent.mult = div_sc(MFGPT_HZ, NSEC_PER_SEC, 32); - mfgpt_clockevent.min_delta_ns = clockevent_delta2ns(0xF, &mfgpt_clockevent); - mfgpt_clockevent.max_delta_ns = clockevent_delta2ns(0xFFFE, &mfgpt_clockevent); - - printk("mfgpt-timer: registering the MFGT timer as a clock event.\n"); - clockevents_register_device(&mfgpt_clockevent); - - return 0; - -err: - geode_mfgpt_release_irq(mfgpt_event_clock, MFGPT_CMP2, irq); - printk(KERN_ERR "mfgpt-timer: Unable to set up the MFGPT clock source\n"); - return -EIO; -} - -#endif |