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[PATCH] char/rtc: Handle memory-mapped chips properly

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Handle memory-mapped chips properly, needed for example on DECstations.
This support was in Linux 2.4 but for some reason got lost in 2.6.  This
patch is taken directly from the linux-mips repository.

[akpm@osdl.org: cleanup]
Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: Martin Michlmayr <tbm@cyrius.com>
Cc: Paul Gortmaker <penguin@muskoka.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Maciej W. Rozycki 2006-07-10 04:45:30 -07:00 committed by Linus Torvalds
parent 06c67befee
commit 38e0e8c055
3 changed files with 41 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

41
drivers/char/rtc.c
View File

@ -46,13 +46,12 @@
* 1.11a Daniele Bellucci: Audit create_proc_read_entry in rtc_init
* 1.12 Venkatesh Pallipadi: Hooks for emulating rtc on HPET base-timer
* CONFIG_HPET_EMULATE_RTC
* 1.12a Maciej W. Rozycki: Handle memory-mapped chips properly.
* 1.12ac Alan Cox: Allow read access to the day of week register
*/
#define RTC_VERSION "1.12ac"
#define RTC_IO_EXTENT 0x8
/*
* Note that *all* calls to CMOS_READ and CMOS_WRITE are done with
* interrupts disabled. Due to the index-port/data-port (0x70/0x71)
@ -337,7 +336,15 @@ static ssize_t rtc_read(struct file *file, char __user *buf,
if (rtc_has_irq == 0)
return -EIO;
if (count < sizeof(unsigned))
/*
* Historically this function used to assume that sizeof(unsigned long)
* is the same in userspace and kernelspace. This lead to problems
* for configurations with multiple ABIs such a the MIPS o32 and 64
* ABIs supported on the same kernel. So now we support read of both
* 4 and 8 bytes and assume that's the sizeof(unsigned long) in the
* userspace ABI.
*/
if (count != sizeof(unsigned int) && count != sizeof(unsigned long))
return -EINVAL;
add_wait_queue(&rtc_wait, &wait);
@ -368,10 +375,12 @@ static ssize_t rtc_read(struct file *file, char __user *buf,
schedule();
} while (1);
if (count < sizeof(unsigned long))
retval = put_user(data, (unsigned int __user *)buf) ?: sizeof(int);
if (count == sizeof(unsigned int))
retval = put_user(data, (unsigned int __user *)buf) ?: sizeof(int);
else
retval = put_user(data, (unsigned long __user *)buf) ?: sizeof(long);
if (!retval)
retval = count;
out:
current->state = TASK_RUNNING;
remove_wait_queue(&rtc_wait, &wait);
@ -923,6 +932,9 @@ static int __init rtc_init(void)
struct sparc_isa_device *isa_dev;
#endif
#endif
#ifndef __sparc__
void *r;
#endif
#ifdef __sparc__
for_each_ebus(ebus) {
@ -964,8 +976,13 @@ found:
}
no_irq:
#else
if (!request_region(RTC_PORT(0), RTC_IO_EXTENT, "rtc")) {
printk(KERN_ERR "rtc: I/O port %d is not free.\n", RTC_PORT (0));
if (RTC_IOMAPPED)
r = request_region(RTC_PORT(0), RTC_IO_EXTENT, "rtc");
else
r = request_mem_region(RTC_PORT(0), RTC_IO_EXTENT, "rtc");
if (!r) {
printk(KERN_ERR "rtc: I/O resource %lx is not free.\n",
(long)(RTC_PORT(0)));
return -EIO;
}
@ -979,7 +996,10 @@ no_irq:
if(request_irq(RTC_IRQ, rtc_int_handler_ptr, IRQF_DISABLED, "rtc", NULL)) {
/* Yeah right, seeing as irq 8 doesn't even hit the bus. */
printk(KERN_ERR "rtc: IRQ %d is not free.\n", RTC_IRQ);
release_region(RTC_PORT(0), RTC_IO_EXTENT);
if (RTC_IOMAPPED)
release_region(RTC_PORT(0), RTC_IO_EXTENT);
else
release_mem_region(RTC_PORT(0), RTC_IO_EXTENT);
return -EIO;
}
hpet_rtc_timer_init();
@ -1079,7 +1099,10 @@ static void __exit rtc_exit (void)
if (rtc_has_irq)
free_irq (rtc_irq, &rtc_port);
#else
release_region (RTC_PORT (0), RTC_IO_EXTENT);
if (RTC_IOMAPPED)
release_region(RTC_PORT(0), RTC_IO_EXTENT);
else
release_mem_region(RTC_PORT(0), RTC_IO_EXTENT);
#ifdef RTC_IRQ
if (rtc_has_irq)
free_irq (RTC_IRQ, NULL);

2
include/asm-mips/mach-dec/mc146818rtc.h
View File

@ -19,6 +19,8 @@
extern volatile u8 *dec_rtc_base;
#define ARCH_RTC_LOCATION
#define RTC_PORT(x) CPHYSADDR((long)dec_rtc_base)
#define RTC_IO_EXTENT dec_kn_slot_size
#define RTC_IOMAPPED 0

7
include/linux/mc146818rtc.h
View File

@ -89,4 +89,11 @@ extern spinlock_t rtc_lock; /* serialize CMOS RAM access */
# define RTC_VRT 0x80 /* valid RAM and time */
/**********************************************************************/
#ifndef ARCH_RTC_LOCATION /* Override by <asm/mc146818rtc.h>? */
#define RTC_IO_EXTENT 0x8
#define RTC_IOMAPPED 1 /* Default to I/O mapping. */
#endif /* ARCH_RTC_LOCATION */
#endif /* _MC146818RTC_H */