diff options
| -rw-r--r-- | drivers/rtc/rtc-cmos.c | 70 |
1 files changed, 63 insertions, 7 deletions
diff --git a/drivers/rtc/rtc-cmos.c b/drivers/rtc/rtc-cmos.c index 963ad0b6a4e9..f1695d7fa0fa 100644 --- a/drivers/rtc/rtc-cmos.c +++ b/drivers/rtc/rtc-cmos.c @@ -143,6 +143,43 @@ static inline int hpet_unregister_irq_handler(irq_handler_t handler) /*----------------------------------------------------------------*/ +#ifdef RTC_PORT + +/* Most newer x86 systems have two register banks, the first used + * for RTC and NVRAM and the second only for NVRAM. Caller must + * own rtc_lock ... and we won't worry about access during NMI. + */ +#define can_bank2 true + +static inline unsigned char cmos_read_bank2(unsigned char addr) +{ + outb(addr, RTC_PORT(2)); + return inb(RTC_PORT(3)); +} + +static inline void cmos_write_bank2(unsigned char val, unsigned char addr) +{ + outb(addr, RTC_PORT(2)); + outb(val, RTC_PORT(2)); +} + +#else + +#define can_bank2 false + +static inline unsigned char cmos_read_bank2(unsigned char addr) +{ + return 0; +} + +static inline void cmos_write_bank2(unsigned char val, unsigned char addr) +{ +} + +#endif + +/*----------------------------------------------------------------*/ + static int cmos_read_time(struct device *dev, struct rtc_time *t) { /* REVISIT: if the clock has a "century" register, use @@ -491,12 +528,21 @@ cmos_nvram_read(struct kobject *kobj, struct bin_attribute *attr, if (unlikely(off >= attr->size)) return 0; + if (unlikely(off < 0)) + return -EINVAL; if ((off + count) > attr->size) count = attr->size - off; + off += NVRAM_OFFSET; spin_lock_irq(&rtc_lock); - for (retval = 0, off += NVRAM_OFFSET; count--; retval++, off++) - *buf++ = CMOS_READ(off); + for (retval = 0; count; count--, off++, retval++) { + if (off < 128) + *buf++ = CMOS_READ(off); + else if (can_bank2) + *buf++ = cmos_read_bank2(off); + else + break; + } spin_unlock_irq(&rtc_lock); return retval; @@ -512,6 +558,8 @@ cmos_nvram_write(struct kobject *kobj, struct bin_attribute *attr, cmos = dev_get_drvdata(container_of(kobj, struct device, kobj)); if (unlikely(off >= attr->size)) return -EFBIG; + if (unlikely(off < 0)) + return -EINVAL; if ((off + count) > attr->size) count = attr->size - off; @@ -520,15 +568,20 @@ cmos_nvram_write(struct kobject *kobj, struct bin_attribute *attr, * here. If userspace is smart enough to know what fields of * NVRAM to update, updating checksums is also part of its job. */ + off += NVRAM_OFFSET; spin_lock_irq(&rtc_lock); - for (retval = 0, off += NVRAM_OFFSET; count--; retval++, off++) { + for (retval = 0; count; count--, off++, retval++) { /* don't trash RTC registers */ if (off == cmos->day_alrm || off == cmos->mon_alrm || off == cmos->century) buf++; - else + else if (off < 128) CMOS_WRITE(*buf++, off); + else if (can_bank2) + cmos_write_bank2(*buf++, off); + else + break; } spin_unlock_irq(&rtc_lock); @@ -631,8 +684,8 @@ cmos_do_probe(struct device *dev, struct resource *ports, int rtc_irq) /* Heuristic to deduce NVRAM size ... do what the legacy NVRAM * driver did, but don't reject unknown configs. Old hardware - * won't address 128 bytes, and for now we ignore the way newer - * chips can address 256 bytes (using two more i/o ports). + * won't address 128 bytes. Newer chips have multiple banks, + * though they may not be listed in one I/O resource. */ #if defined(CONFIG_ATARI) address_space = 64; @@ -642,6 +695,8 @@ cmos_do_probe(struct device *dev, struct resource *ports, int rtc_irq) #warning Assuming 128 bytes of RTC+NVRAM address space, not 64 bytes. address_space = 128; #endif + if (can_bank2 && ports->end > (ports->start + 1)) + address_space = 256; /* For ACPI systems extension info comes from the FADT. On others, * board specific setup provides it as appropriate. Systems where @@ -740,7 +795,7 @@ cmos_do_probe(struct device *dev, struct resource *ports, int rtc_irq) goto cleanup2; } - pr_info("%s: alarms up to one %s%s%s\n", + pr_info("%s: alarms up to one %s%s, %zd bytes nvram, %s irqs\n", cmos_rtc.rtc->dev.bus_id, is_valid_irq(rtc_irq) ? (cmos_rtc.mon_alrm @@ -749,6 +804,7 @@ cmos_do_probe(struct device *dev, struct resource *ports, int rtc_irq) ? "month" : "day")) : "no", cmos_rtc.century ? ", y3k" : "", + nvram.size, is_hpet_enabled() ? ", hpet irqs" : ""); return 0; |