x86: Geode Multi-Function General Purpose Timers support (83d7384f) · Commits · 戴 / test

Documentation/kernel-parameters.txt

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		@@ -1160,6 +1160,9 @@ and is between 256 and 4096 characters. It is defined in the file

		nomce [X86-32] Machine Check Exception

		nomfgpt [X86-32] Disable Multi-Function General Purpose
		Timer usage (for AMD Geode machines).

		noreplace-paravirt [X86-32,PV_OPS] Don't patch paravirt_ops

		noreplace-smp [X86-32,SMP] Don't replace SMP instructions

arch/x86/kernel/Makefile_32

+1 −1

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		@@ -39,7 +39,7 @@ obj-$(CONFIG_VM86) += vm86_32.o
		obj-$(CONFIG_EARLY_PRINTK) += early_printk.o
		obj-$(CONFIG_HPET_TIMER) += hpet_32.o
		obj-$(CONFIG_K8_NB) += k8.o
		obj-$(CONFIG_MGEODE_LX) += geode_32.o
		obj-$(CONFIG_MGEODE_LX) += geode_32.o mfgpt_32.o

		obj-$(CONFIG_VMI) += vmi_32.o vmiclock_32.o
		obj-$(CONFIG_PARAVIRT) += paravirt_32.o

arch/x86/kernel/geode_32.c

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		@@ -145,10 +145,14 @@ EXPORT_SYMBOL_GPL(geode_gpio_setup_event);

		static int __init geode_southbridge_init(void)
		{
		int timers;

		if (!is_geode())
		return -ENODEV;

		init_lbars();
		timers = geode_mfgpt_detect();
		printk(KERN_INFO "geode: %d MFGPT timers available.\n", timers);
		return 0;
		}

arch/x86/kernel/mfgpt_32.c

0 → 100644

+197 −0

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		/*
		* Driver/API for AMD Geode Multi-Function General Purpose Timers (MFGPT)
		*
		* Copyright (C) 2006, Advanced Micro Devices, Inc.
		* Copyright (C) 2007, Andres Salomon <dilinger@debian.org>
		*
		* This program is free software; you can redistribute it and/or
		* modify it under the terms of version 2 of the GNU General Public License
		* as published by the Free Software Foundation.
		*
		* The MFGPTs are documented in AMD Geode CS5536 Companion Device Data Book.
		*/

		/*
		* 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 <asm/geode.h>

		#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)

		/* Allow for disabling of MFGPTs */
		static int disable;
		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++;
		}
		}

		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? -dilinger
		*/
		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;
		}

		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(MSR_PIC_ZSEL_LOW, val, dummy);

		offset = (timer % 4) * 4;

		val &= ~((0xF << offset) \| (0xF << (offset + 16)));

		if (enable) {
		val \|= (irq & 0x0F) << (offset);
		val \|= (irq & 0x0F) << (offset + 16);
		}

		wrmsr(MSR_PIC_ZSEL_LOW, val, dummy);
		return 0;
		}

		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;
		}

include/asm-x86/geode.h

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Original line number	Diff line number	Diff line
		@@ -156,4 +156,54 @@ static inline int is_geode(void)
		return (is_geode_gx() \|\| is_geode_lx());
		}

		/* MFGPTs */

		#define MFGPT_MAX_TIMERS 8
		#define MFGPT_TIMER_ANY -1

		#define MFGPT_DOMAIN_WORKING 1
		#define MFGPT_DOMAIN_STANDBY 2
		#define MFGPT_DOMAIN_ANY (MFGPT_DOMAIN_WORKING \| MFGPT_DOMAIN_STANDBY)

		#define MFGPT_CMP1 0
		#define MFGPT_CMP2 1

		#define MFGPT_EVENT_IRQ 0
		#define MFGPT_EVENT_NMI 1
		#define MFGPT_EVENT_RESET 3

		#define MFGPT_REG_CMP1 0
		#define MFGPT_REG_CMP2 2
		#define MFGPT_REG_COUNTER 4
		#define MFGPT_REG_SETUP 6

		#define MFGPT_SETUP_CNTEN (1 << 15)
		#define MFGPT_SETUP_CMP2 (1 << 14)
		#define MFGPT_SETUP_CMP1 (1 << 13)
		#define MFGPT_SETUP_SETUP (1 << 12)
		#define MFGPT_SETUP_STOPEN (1 << 11)
		#define MFGPT_SETUP_EXTEN (1 << 10)
		#define MFGPT_SETUP_REVEN (1 << 5)
		#define MFGPT_SETUP_CLKSEL (1 << 4)

		static inline void geode_mfgpt_write(int timer, u16 reg, u16 value)
		{
		u32 base = geode_get_dev_base(GEODE_DEV_MFGPT);
		outw(value, base + reg + (timer * 8));
		}

		static inline u16 geode_mfgpt_read(int timer, u16 reg)
		{
		u32 base = geode_get_dev_base(GEODE_DEV_MFGPT);
		return inw(base + reg + (timer * 8));
		}

		extern int __init geode_mfgpt_detect(void);
		extern int geode_mfgpt_toggle_event(int timer, int cmp, int event, int enable);
		extern int geode_mfgpt_set_irq(int timer, int cmp, int irq, int enable);
		extern int geode_mfgpt_alloc_timer(int timer, int domain, struct module *owner);

		#define geode_mfgpt_setup_irq(t, c, i) geode_mfgpt_set_irq((t), (c), (i), 1)
		#define geode_mfgpt_release_irq(t, c, i) geode_mfgpt_set_irq((t), (c), (i), 0)

		#endif

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