linux/arch/x86/include/asm/hpet.h
Thomas Gleixner 30a564be9d x86, hpet: Restrict read back to affected ATI chipsets
After programming the HPET, we do a readback as a workaround for
ATI/SBx00 chipsets as a synchronization.  Unfortunately this triggers
an erratum in newer ICH chipsets (ICH9+) where reading the comparator
immediately after the write returns the old value.  Furthermore, as
always, I/O reads are bad for performance.

Therefore, restrict the readback to the chipsets that need it, or, for
debugging purposes, when we are running with hpet=verbose.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Venkatesh Pallipadi <venki@google.com>
LKML-Reference: <20100225185348.GA9674@linux-os.sc.intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2010-04-28 18:14:29 -07:00

118 lines
3.3 KiB
C

#ifndef _ASM_X86_HPET_H
#define _ASM_X86_HPET_H
#include <linux/msi.h>
#ifdef CONFIG_HPET_TIMER
#define HPET_MMAP_SIZE 1024
#define HPET_ID 0x000
#define HPET_PERIOD 0x004
#define HPET_CFG 0x010
#define HPET_STATUS 0x020
#define HPET_COUNTER 0x0f0
#define HPET_Tn_CFG(n) (0x100 + 0x20 * n)
#define HPET_Tn_CMP(n) (0x108 + 0x20 * n)
#define HPET_Tn_ROUTE(n) (0x110 + 0x20 * n)
#define HPET_T0_CFG 0x100
#define HPET_T0_CMP 0x108
#define HPET_T0_ROUTE 0x110
#define HPET_T1_CFG 0x120
#define HPET_T1_CMP 0x128
#define HPET_T1_ROUTE 0x130
#define HPET_T2_CFG 0x140
#define HPET_T2_CMP 0x148
#define HPET_T2_ROUTE 0x150
#define HPET_ID_REV 0x000000ff
#define HPET_ID_NUMBER 0x00001f00
#define HPET_ID_64BIT 0x00002000
#define HPET_ID_LEGSUP 0x00008000
#define HPET_ID_VENDOR 0xffff0000
#define HPET_ID_NUMBER_SHIFT 8
#define HPET_ID_VENDOR_SHIFT 16
#define HPET_ID_VENDOR_8086 0x8086
#define HPET_CFG_ENABLE 0x001
#define HPET_CFG_LEGACY 0x002
#define HPET_LEGACY_8254 2
#define HPET_LEGACY_RTC 8
#define HPET_TN_LEVEL 0x0002
#define HPET_TN_ENABLE 0x0004
#define HPET_TN_PERIODIC 0x0008
#define HPET_TN_PERIODIC_CAP 0x0010
#define HPET_TN_64BIT_CAP 0x0020
#define HPET_TN_SETVAL 0x0040
#define HPET_TN_32BIT 0x0100
#define HPET_TN_ROUTE 0x3e00
#define HPET_TN_FSB 0x4000
#define HPET_TN_FSB_CAP 0x8000
#define HPET_TN_ROUTE_SHIFT 9
/* Max HPET Period is 10^8 femto sec as in HPET spec */
#define HPET_MAX_PERIOD 100000000UL
/*
* Min HPET period is 10^5 femto sec just for safety. If it is less than this,
* then 32 bit HPET counter wrapsaround in less than 0.5 sec.
*/
#define HPET_MIN_PERIOD 100000UL
/* hpet memory map physical address */
extern unsigned long hpet_address;
extern unsigned long force_hpet_address;
extern u8 hpet_blockid;
extern int hpet_force_user;
extern u8 hpet_msi_disable;
extern u8 hpet_readback_cmp;
extern int is_hpet_enabled(void);
extern int hpet_enable(void);
extern void hpet_disable(void);
extern unsigned int hpet_readl(unsigned int a);
extern void force_hpet_resume(void);
extern void hpet_msi_unmask(unsigned int irq);
extern void hpet_msi_mask(unsigned int irq);
extern void hpet_msi_write(unsigned int irq, struct msi_msg *msg);
extern void hpet_msi_read(unsigned int irq, struct msi_msg *msg);
#ifdef CONFIG_PCI_MSI
extern int arch_setup_hpet_msi(unsigned int irq, unsigned int id);
#else
static inline int arch_setup_hpet_msi(unsigned int irq, unsigned int id)
{
return -EINVAL;
}
#endif
#ifdef CONFIG_HPET_EMULATE_RTC
#include <linux/interrupt.h>
typedef irqreturn_t (*rtc_irq_handler)(int interrupt, void *cookie);
extern int hpet_mask_rtc_irq_bit(unsigned long bit_mask);
extern int hpet_set_rtc_irq_bit(unsigned long bit_mask);
extern int hpet_set_alarm_time(unsigned char hrs, unsigned char min,
unsigned char sec);
extern int hpet_set_periodic_freq(unsigned long freq);
extern int hpet_rtc_dropped_irq(void);
extern int hpet_rtc_timer_init(void);
extern irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id);
extern int hpet_register_irq_handler(rtc_irq_handler handler);
extern void hpet_unregister_irq_handler(rtc_irq_handler handler);
#endif /* CONFIG_HPET_EMULATE_RTC */
#else /* CONFIG_HPET_TIMER */
static inline int hpet_enable(void) { return 0; }
static inline int is_hpet_enabled(void) { return 0; }
#define hpet_readl(a) 0
#endif
#endif /* _ASM_X86_HPET_H */