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authorMaciej W. Rozycki <macro@linux-mips.org>2006-07-10 04:45:30 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2006-07-10 13:24:25 -0700
commit38e0e8c0550eaed1af48ec5ad9ddb8a25e8b04ae (patch)
treef38daa22e42969c8eabccfd73dc298dcaec99821 /drivers/char/rtc.c
parent06c67befeeb16f2995c11b0e04a348103ddbfab1 (diff)
downloadlwn-38e0e8c0550eaed1af48ec5ad9ddb8a25e8b04ae.tar.gz
lwn-38e0e8c0550eaed1af48ec5ad9ddb8a25e8b04ae.zip
[PATCH] char/rtc: Handle memory-mapped chips properly
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>
Diffstat (limited to 'drivers/char/rtc.c')
-rw-r--r--drivers/char/rtc.c41
1 files changed, 32 insertions, 9 deletions
diff --git a/drivers/char/rtc.c b/drivers/char/rtc.c
index cc7bd1a3095b..6ccc364c08df 100644
--- a/drivers/char/rtc.c
+++ b/drivers/char/rtc.c
@@ -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);