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path: root/drivers/rtc/rtc-cmos.c
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Diffstat (limited to 'drivers/rtc/rtc-cmos.c')
-rw-r--r--drivers/rtc/rtc-cmos.c221
1 files changed, 197 insertions, 24 deletions
diff --git a/drivers/rtc/rtc-cmos.c b/drivers/rtc/rtc-cmos.c
index 29cf1457ca1..e059f94c79e 100644
--- a/drivers/rtc/rtc-cmos.c
+++ b/drivers/rtc/rtc-cmos.c
@@ -36,9 +36,24 @@
#include <linux/platform_device.h>
#include <linux/mod_devicetable.h>
+#ifdef CONFIG_HPET_EMULATE_RTC
+#include <asm/hpet.h>
+#endif
+
/* this is for "generic access to PC-style RTC" using CMOS_READ/CMOS_WRITE */
#include <asm-generic/rtc.h>
+#ifndef CONFIG_HPET_EMULATE_RTC
+#define is_hpet_enabled() 0
+#define hpet_set_alarm_time(hrs, min, sec) do { } while (0)
+#define hpet_set_periodic_freq(arg) 0
+#define hpet_mask_rtc_irq_bit(arg) do { } while (0)
+#define hpet_set_rtc_irq_bit(arg) do { } while (0)
+#define hpet_rtc_timer_init() do { } while (0)
+#define hpet_register_irq_handler(h) 0
+#define hpet_unregister_irq_handler(h) do { } while (0)
+extern irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id);
+#endif
struct cmos_rtc {
struct rtc_device *rtc;
@@ -199,6 +214,7 @@ static int cmos_set_alarm(struct device *dev, struct rtc_wkalrm *t)
sec = t->time.tm_sec;
sec = (sec < 60) ? BIN2BCD(sec) : 0xff;
+ hpet_set_alarm_time(t->time.tm_hour, t->time.tm_min, t->time.tm_sec);
spin_lock_irq(&rtc_lock);
/* next rtc irq must not be from previous alarm setting */
@@ -252,7 +268,8 @@ static int cmos_irq_set_freq(struct device *dev, int freq)
f = 16 - f;
spin_lock_irqsave(&rtc_lock, flags);
- CMOS_WRITE(RTC_REF_CLCK_32KHZ | f, RTC_FREQ_SELECT);
+ if (!hpet_set_periodic_freq(freq))
+ CMOS_WRITE(RTC_REF_CLCK_32KHZ | f, RTC_FREQ_SELECT);
spin_unlock_irqrestore(&rtc_lock, flags);
return 0;
@@ -314,28 +331,37 @@ cmos_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
switch (cmd) {
case RTC_AIE_OFF: /* alarm off */
rtc_control &= ~RTC_AIE;
+ hpet_mask_rtc_irq_bit(RTC_AIE);
break;
case RTC_AIE_ON: /* alarm on */
rtc_control |= RTC_AIE;
+ hpet_set_rtc_irq_bit(RTC_AIE);
break;
case RTC_UIE_OFF: /* update off */
rtc_control &= ~RTC_UIE;
+ hpet_mask_rtc_irq_bit(RTC_UIE);
break;
case RTC_UIE_ON: /* update on */
rtc_control |= RTC_UIE;
+ hpet_set_rtc_irq_bit(RTC_UIE);
break;
case RTC_PIE_OFF: /* periodic off */
rtc_control &= ~RTC_PIE;
+ hpet_mask_rtc_irq_bit(RTC_PIE);
break;
case RTC_PIE_ON: /* periodic on */
rtc_control |= RTC_PIE;
+ hpet_set_rtc_irq_bit(RTC_PIE);
break;
}
- CMOS_WRITE(rtc_control, RTC_CONTROL);
+ if (!is_hpet_enabled())
+ CMOS_WRITE(rtc_control, RTC_CONTROL);
+
rtc_intr = CMOS_READ(RTC_INTR_FLAGS);
rtc_intr &= (rtc_control & RTC_IRQMASK) | RTC_IRQF;
if (is_intr(rtc_intr))
rtc_update_irq(cmos->rtc, 1, rtc_intr);
+
spin_unlock_irqrestore(&rtc_lock, flags);
return 0;
}
@@ -393,15 +419,111 @@ static const struct rtc_class_ops cmos_rtc_ops = {
/*----------------------------------------------------------------*/
+/*
+ * All these chips have at least 64 bytes of address space, shared by
+ * RTC registers and NVRAM. Most of those bytes of NVRAM are used
+ * by boot firmware. Modern chips have 128 or 256 bytes.
+ */
+
+#define NVRAM_OFFSET (RTC_REG_D + 1)
+
+static ssize_t
+cmos_nvram_read(struct kobject *kobj, struct bin_attribute *attr,
+ char *buf, loff_t off, size_t count)
+{
+ int retval;
+
+ if (unlikely(off >= attr->size))
+ return 0;
+ if ((off + count) > attr->size)
+ count = attr->size - off;
+
+ spin_lock_irq(&rtc_lock);
+ for (retval = 0, off += NVRAM_OFFSET; count--; retval++, off++)
+ *buf++ = CMOS_READ(off);
+ spin_unlock_irq(&rtc_lock);
+
+ return retval;
+}
+
+static ssize_t
+cmos_nvram_write(struct kobject *kobj, struct bin_attribute *attr,
+ char *buf, loff_t off, size_t count)
+{
+ struct cmos_rtc *cmos;
+ int retval;
+
+ cmos = dev_get_drvdata(container_of(kobj, struct device, kobj));
+ if (unlikely(off >= attr->size))
+ return -EFBIG;
+ if ((off + count) > attr->size)
+ count = attr->size - off;
+
+ /* NOTE: on at least PCs and Ataris, the boot firmware uses a
+ * checksum on part of the NVRAM data. That's currently ignored
+ * here. If userspace is smart enough to know what fields of
+ * NVRAM to update, updating checksums is also part of its job.
+ */
+ spin_lock_irq(&rtc_lock);
+ for (retval = 0, off += NVRAM_OFFSET; count--; retval++, off++) {
+ /* don't trash RTC registers */
+ if (off == cmos->day_alrm
+ || off == cmos->mon_alrm
+ || off == cmos->century)
+ buf++;
+ else
+ CMOS_WRITE(*buf++, off);
+ }
+ spin_unlock_irq(&rtc_lock);
+
+ return retval;
+}
+
+static struct bin_attribute nvram = {
+ .attr = {
+ .name = "nvram",
+ .mode = S_IRUGO | S_IWUSR,
+ .owner = THIS_MODULE,
+ },
+
+ .read = cmos_nvram_read,
+ .write = cmos_nvram_write,
+ /* size gets set up later */
+};
+
+/*----------------------------------------------------------------*/
+
static struct cmos_rtc cmos_rtc;
static irqreturn_t cmos_interrupt(int irq, void *p)
{
u8 irqstat;
+ u8 rtc_control;
spin_lock(&rtc_lock);
- irqstat = CMOS_READ(RTC_INTR_FLAGS);
- irqstat &= (CMOS_READ(RTC_CONTROL) & RTC_IRQMASK) | RTC_IRQF;
+ /*
+ * In this case it is HPET RTC interrupt handler
+ * calling us, with the interrupt information
+ * passed as arg1, instead of irq.
+ */
+ if (is_hpet_enabled())
+ irqstat = (unsigned long)irq & 0xF0;
+ else {
+ irqstat = CMOS_READ(RTC_INTR_FLAGS);
+ rtc_control = CMOS_READ(RTC_CONTROL);
+ irqstat &= (rtc_control & RTC_IRQMASK) | RTC_IRQF;
+ }
+
+ /* All Linux RTC alarms should be treated as if they were oneshot.
+ * Similar code may be needed in system wakeup paths, in case the
+ * alarm woke the system.
+ */
+ if (irqstat & RTC_AIE) {
+ rtc_control = CMOS_READ(RTC_CONTROL);
+ rtc_control &= ~RTC_AIE;
+ CMOS_WRITE(rtc_control, RTC_CONTROL);
+ CMOS_READ(RTC_INTR_FLAGS);
+ }
spin_unlock(&rtc_lock);
if (is_intr(irqstat)) {
@@ -412,11 +534,9 @@ static irqreturn_t cmos_interrupt(int irq, void *p)
}
#ifdef CONFIG_PNP
-#define is_pnp() 1
#define INITSECTION
#else
-#define is_pnp() 0
#define INITSECTION __init
#endif
@@ -426,6 +546,7 @@ cmos_do_probe(struct device *dev, struct resource *ports, int rtc_irq)
struct cmos_rtc_board_info *info = dev->platform_data;
int retval = 0;
unsigned char rtc_control;
+ unsigned address_space;
/* there can be only one ... */
if (cmos_rtc.dev)
@@ -450,15 +571,36 @@ cmos_do_probe(struct device *dev, struct resource *ports, int rtc_irq)
cmos_rtc.irq = rtc_irq;
cmos_rtc.iomem = ports;
+ /* 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).
+ */
+#if defined(CONFIG_ATARI)
+ address_space = 64;
+#elif defined(__i386__) || defined(__x86_64__) || defined(__arm__)
+ address_space = 128;
+#else
+#warning Assuming 128 bytes of RTC+NVRAM address space, not 64 bytes.
+ address_space = 128;
+#endif
+
/* For ACPI systems extension info comes from the FADT. On others,
* board specific setup provides it as appropriate. Systems where
* the alarm IRQ isn't automatically a wakeup IRQ (like ACPI, and
* some almost-clones) can provide hooks to make that behave.
+ *
+ * Note that ACPI doesn't preclude putting these registers into
+ * "extended" areas of the chip, including some that we won't yet
+ * expect CMOS_READ and friends to handle.
*/
if (info) {
- cmos_rtc.day_alrm = info->rtc_day_alarm;
- cmos_rtc.mon_alrm = info->rtc_mon_alarm;
- cmos_rtc.century = info->rtc_century;
+ if (info->rtc_day_alarm && info->rtc_day_alarm < 128)
+ cmos_rtc.day_alrm = info->rtc_day_alarm;
+ if (info->rtc_mon_alarm && info->rtc_mon_alarm < 128)
+ cmos_rtc.mon_alrm = info->rtc_mon_alarm;
+ if (info->rtc_century && info->rtc_century < 128)
+ cmos_rtc.century = info->rtc_century;
if (info->wake_on && info->wake_off) {
cmos_rtc.wake_on = info->wake_on;
@@ -485,8 +627,9 @@ cmos_do_probe(struct device *dev, struct resource *ports, int rtc_irq)
* doesn't use 32KHz here ... for portability we might need to
* do something about other clock frequencies.
*/
- CMOS_WRITE(RTC_REF_CLCK_32KHZ | 0x06, RTC_FREQ_SELECT);
cmos_rtc.rtc->irq_freq = 1024;
+ if (!hpet_set_periodic_freq(cmos_rtc.rtc->irq_freq))
+ CMOS_WRITE(RTC_REF_CLCK_32KHZ | 0x06, RTC_FREQ_SELECT);
/* disable irqs.
*
@@ -509,19 +652,39 @@ cmos_do_probe(struct device *dev, struct resource *ports, int rtc_irq)
goto cleanup1;
}
- if (is_valid_irq(rtc_irq))
- retval = request_irq(rtc_irq, cmos_interrupt, IRQF_DISABLED,
- cmos_rtc.rtc->dev.bus_id,
+ if (is_valid_irq(rtc_irq)) {
+ irq_handler_t rtc_cmos_int_handler;
+
+ if (is_hpet_enabled()) {
+ int err;
+
+ rtc_cmos_int_handler = hpet_rtc_interrupt;
+ err = hpet_register_irq_handler(cmos_interrupt);
+ if (err != 0) {
+ printk(KERN_WARNING "hpet_register_irq_handler "
+ " failed in rtc_init().");
+ goto cleanup1;
+ }
+ } else
+ rtc_cmos_int_handler = cmos_interrupt;
+
+ retval = request_irq(rtc_irq, rtc_cmos_int_handler,
+ IRQF_DISABLED, cmos_rtc.rtc->dev.bus_id,
cmos_rtc.rtc);
- if (retval < 0) {
- dev_dbg(dev, "IRQ %d is already in use\n", rtc_irq);
- goto cleanup1;
+ if (retval < 0) {
+ dev_dbg(dev, "IRQ %d is already in use\n", rtc_irq);
+ goto cleanup1;
+ }
}
+ hpet_rtc_timer_init();
- /* REVISIT optionally make 50 or 114 bytes NVRAM available,
- * like rtc-ds1553, rtc-ds1742 ... this will often include
- * registers for century, and day/month alarm.
- */
+ /* export at least the first block of NVRAM */
+ nvram.size = address_space - NVRAM_OFFSET;
+ retval = sysfs_create_bin_file(&dev->kobj, &nvram);
+ if (retval < 0) {
+ dev_dbg(dev, "can't create nvram file? %d\n", retval);
+ goto cleanup2;
+ }
pr_info("%s: alarms up to one %s%s\n",
cmos_rtc.rtc->dev.bus_id,
@@ -536,6 +699,9 @@ cmos_do_probe(struct device *dev, struct resource *ports, int rtc_irq)
return 0;
+cleanup2:
+ if (is_valid_irq(rtc_irq))
+ free_irq(rtc_irq, cmos_rtc.rtc);
cleanup1:
cmos_rtc.dev = NULL;
rtc_device_unregister(cmos_rtc.rtc);
@@ -563,8 +729,12 @@ static void __exit cmos_do_remove(struct device *dev)
cmos_do_shutdown();
- if (is_valid_irq(cmos->irq))
+ sysfs_remove_bin_file(&dev->kobj, &nvram);
+
+ if (is_valid_irq(cmos->irq)) {
free_irq(cmos->irq, cmos->rtc);
+ hpet_unregister_irq_handler(cmos_interrupt);
+ }
rtc_device_unregister(cmos->rtc);
cmos->rtc = NULL;
@@ -659,9 +829,12 @@ static int cmos_resume(struct device *dev)
/*----------------------------------------------------------------*/
-/* The "CMOS" RTC normally lives on the platform_bus. On ACPI systems,
- * the device node will always be created as a PNPACPI device. Plus
- * pre-ACPI PCs probably list it in the PNPBIOS tables.
+/* On non-x86 systems, a "CMOS" RTC lives most naturally on platform_bus.
+ * ACPI systems always list these as PNPACPI devices, and pre-ACPI PCs
+ * probably list them in similar PNPBIOS tables; so PNP is more common.
+ *
+ * We don't use legacy "poke at the hardware" probing. Ancient PCs that
+ * predate even PNPBIOS should set up platform_bus devices.
*/
#ifdef CONFIG_PNP
generated by cgit v1.2.3 (git 2.39.1) at 2024-05-22 09:31:50 +0000