#include <linux/rtc.h>
#include <linux/slab.h>
-/* set to 1 = busy every eight 32kHz clocks during copy of sec+msec to AHB */
+/* Set to 1 = busy every eight 32 kHz clocks during copy of sec+msec to AHB. */
#define TEGRA_RTC_REG_BUSY 0x004
#define TEGRA_RTC_REG_SECONDS 0x008
-/* when msec is read, the seconds are buffered into shadow seconds. */
+/* When msec is read, the seconds are buffered into shadow seconds. */
#define TEGRA_RTC_REG_SHADOW_SECONDS 0x00c
#define TEGRA_RTC_REG_MILLI_SECONDS 0x010
#define TEGRA_RTC_REG_SECONDS_ALARM0 0x014
#define TEGRA_RTC_INTR_STATUS_SEC_ALARM0 (1<<0)
struct tegra_rtc_info {
- struct platform_device *pdev;
- struct rtc_device *rtc_dev;
- void __iomem *rtc_base; /* NULL if not initialized. */
- struct clk *clk;
- int tegra_rtc_irq; /* alarm and periodic irq */
- spinlock_t tegra_rtc_lock;
+ struct platform_device *pdev;
+ struct rtc_device *rtc_dev;
+ void __iomem *rtc_base; /* NULL if not initialized */
+ struct clk *clk;
+ int tegra_rtc_irq; /* alarm and periodic IRQ */
+ spinlock_t tegra_rtc_lock;
};
-/* RTC hardware is busy when it is updating its values over AHB once
- * every eight 32kHz clocks (~250uS).
- * outside of these updates the CPU is free to write.
- * CPU is always free to read.
+/*
+ * RTC hardware is busy when it is updating its values over AHB once every
+ * eight 32 kHz clocks (~250 us). Outside of these updates the CPU is free to
+ * write. CPU is always free to read.
*/
static inline u32 tegra_rtc_check_busy(struct tegra_rtc_info *info)
{
return readl(info->rtc_base + TEGRA_RTC_REG_BUSY) & 1;
}
-/* Wait for hardware to be ready for writing.
- * This function tries to maximize the amount of time before the next update.
- * It does this by waiting for the RTC to become busy with its periodic update,
- * then returning once the RTC first becomes not busy.
+/*
+ * Wait for hardware to be ready for writing. This function tries to maximize
+ * the amount of time before the next update. It does this by waiting for the
+ * RTC to become busy with its periodic update, then returning once the RTC
+ * first becomes not busy.
+ *
* This periodic update (where the seconds and milliseconds are copied to the
- * AHB side) occurs every eight 32kHz clocks (~250uS).
- * The behavior of this function allows us to make some assumptions without
- * introducing a race, because 250uS is plenty of time to read/write a value.
+ * AHB side) occurs every eight 32 kHz clocks (~250 us). The behavior of this
+ * function allows us to make some assumptions without introducing a race,
+ * because 250 us is plenty of time to read/write a value.
*/
static int tegra_rtc_wait_while_busy(struct device *dev)
{
struct tegra_rtc_info *info = dev_get_drvdata(dev);
+ int retries = 500; /* ~490 us is the worst case, ~250 us is best */
- int retries = 500; /* ~490 us is the worst case, ~250 us is best. */
-
- /* first wait for the RTC to become busy. this is when it
- * posts its updated seconds+msec registers to AHB side. */
+ /*
+ * First wait for the RTC to become busy. This is when it posts its
+ * updated seconds+msec registers to AHB side.
+ */
while (tegra_rtc_check_busy(info)) {
if (!retries--)
goto retry_failed;
+
udelay(1);
}
return 0;
retry_failed:
- dev_err(dev, "write failed:retry count exceeded.\n");
+ dev_err(dev, "write failed: retry count exceeded\n");
return -ETIMEDOUT;
}
unsigned long sec, msec;
unsigned long sl_irq_flags;
- /* RTC hardware copies seconds to shadow seconds when a read
- * of milliseconds occurs. use a lock to keep other threads out. */
+ /*
+ * RTC hardware copies seconds to shadow seconds when a read of
+ * milliseconds occurs. use a lock to keep other threads out.
+ */
spin_lock_irqsave(&info->tegra_rtc_lock, sl_irq_flags);
msec = readl(info->rtc_base + TEGRA_RTC_REG_MILLI_SECONDS);
rtc_time64_to_tm(sec, tm);
- dev_vdbg(dev, "time read as %lu. %ptR\n", sec, tm);
+ dev_vdbg(dev, "time read as %u, %ptR\n", sec, tm);
return 0;
}
unsigned long sec;
int ret;
- /* convert tm to seconds. */
+ /* convert tm to seconds */
sec = rtc_tm_to_time64(tm);
- dev_vdbg(dev, "time set to %lu. %ptR\n", sec, tm);
+ dev_vdbg(dev, "time set to %u, %ptR\n", sec, tm);
- /* seconds only written if wait succeeded. */
+ /* seconds only written if wait succeeded */
ret = tegra_rtc_wait_while_busy(dev);
if (!ret)
writel(sec, info->rtc_base + TEGRA_RTC_REG_SECONDS);
dev_vdbg(dev, "time read back as %d\n",
- readl(info->rtc_base + TEGRA_RTC_REG_SECONDS));
+ readl(info->rtc_base + TEGRA_RTC_REG_SECONDS));
return ret;
}
{
struct tegra_rtc_info *info = dev_get_drvdata(dev);
unsigned long sec;
- unsigned tmp;
+ unsigned int tmp;
sec = readl(info->rtc_base + TEGRA_RTC_REG_SECONDS_ALARM0);
if (sec == 0) {
- /* alarm is disabled. */
+ /* alarm is disabled */
alarm->enabled = 0;
} else {
- /* alarm is enabled. */
+ /* alarm is enabled */
alarm->enabled = 1;
rtc_time64_to_tm(sec, &alarm->time);
}
static int tegra_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
{
struct tegra_rtc_info *info = dev_get_drvdata(dev);
- unsigned status;
unsigned long sl_irq_flags;
+ unsigned int status;
tegra_rtc_wait_while_busy(dev);
spin_lock_irqsave(&info->tegra_rtc_lock, sl_irq_flags);
- /* read the original value, and OR in the flag. */
+ /* read the original value, and OR in the flag */
status = readl(info->rtc_base + TEGRA_RTC_REG_INTR_MASK);
if (enabled)
status |= TEGRA_RTC_INTR_MASK_SEC_ALARM0; /* set it */
tegra_rtc_wait_while_busy(dev);
writel(sec, info->rtc_base + TEGRA_RTC_REG_SECONDS_ALARM0);
dev_vdbg(dev, "alarm read back as %d\n",
- readl(info->rtc_base + TEGRA_RTC_REG_SECONDS_ALARM0));
+ readl(info->rtc_base + TEGRA_RTC_REG_SECONDS_ALARM0));
/* if successfully written and alarm is enabled ... */
if (sec) {
tegra_rtc_alarm_irq_enable(dev, 1);
- dev_vdbg(dev, "alarm set as %lu. %ptR\n", sec, &alarm->time);
+ dev_vdbg(dev, "alarm set as %u, %ptR\n", sec, &alarm->time);
} else {
- /* disable alarm if 0 or write error. */
+ /* disable alarm if 0 or write error */
dev_vdbg(dev, "alarm disabled\n");
tegra_rtc_alarm_irq_enable(dev, 0);
}
struct device *dev = data;
struct tegra_rtc_info *info = dev_get_drvdata(dev);
unsigned long events = 0;
- unsigned status;
unsigned long sl_irq_flags;
+ unsigned int status;
status = readl(info->rtc_base + TEGRA_RTC_REG_INTR_STATUS);
if (status) {
- /* clear the interrupt masks and status on any irq. */
+ /* clear the interrupt masks and status on any IRQ */
tegra_rtc_wait_while_busy(dev);
+
spin_lock_irqsave(&info->tegra_rtc_lock, sl_irq_flags);
writel(0, info->rtc_base + TEGRA_RTC_REG_INTR_MASK);
writel(status, info->rtc_base + TEGRA_RTC_REG_INTR_STATUS);
spin_unlock_irqrestore(&info->tegra_rtc_lock, sl_irq_flags);
}
- /* check if Alarm */
- if ((status & TEGRA_RTC_INTR_STATUS_SEC_ALARM0))
+ /* check if alarm */
+ if (status & TEGRA_RTC_INTR_STATUS_SEC_ALARM0)
events |= RTC_IRQF | RTC_AF;
- /* check if Periodic */
- if ((status & TEGRA_RTC_INTR_STATUS_SEC_CDN_ALARM))
+ /* check if periodic */
+ if (status & TEGRA_RTC_INTR_STATUS_SEC_CDN_ALARM)
events |= RTC_IRQF | RTC_PF;
rtc_update_irq(info->rtc_dev, 1, events);
}
static const struct rtc_class_ops tegra_rtc_ops = {
- .read_time = tegra_rtc_read_time,
- .set_time = tegra_rtc_set_time,
- .read_alarm = tegra_rtc_read_alarm,
- .set_alarm = tegra_rtc_set_alarm,
- .proc = tegra_rtc_proc,
+ .read_time = tegra_rtc_read_time,
+ .set_time = tegra_rtc_set_time,
+ .read_alarm = tegra_rtc_read_alarm,
+ .set_alarm = tegra_rtc_set_alarm,
+ .proc = tegra_rtc_proc,
.alarm_irq_enable = tegra_rtc_alarm_irq_enable,
};
struct resource *res;
int ret;
- info = devm_kzalloc(&pdev->dev, sizeof(struct tegra_rtc_info),
- GFP_KERNEL);
+ info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
if (!info)
return -ENOMEM;
if (ret < 0)
return ret;
- /* set context info. */
+ /* set context info */
info->pdev = pdev;
spin_lock_init(&info->tegra_rtc_lock);
platform_set_drvdata(pdev, info);
- /* clear out the hardware. */
+ /* clear out the hardware */
writel(0, info->rtc_base + TEGRA_RTC_REG_SECONDS_ALARM0);
writel(0xffffffff, info->rtc_base + TEGRA_RTC_REG_INTR_STATUS);
writel(0, info->rtc_base + TEGRA_RTC_REG_INTR_MASK);
device_init_wakeup(&pdev->dev, 1);
ret = devm_request_irq(&pdev->dev, info->tegra_rtc_irq,
- tegra_rtc_irq_handler, IRQF_TRIGGER_HIGH,
- dev_name(&pdev->dev), &pdev->dev);
+ tegra_rtc_irq_handler, IRQF_TRIGGER_HIGH,
+ dev_name(&pdev->dev), &pdev->dev);
if (ret) {
- dev_err(&pdev->dev,
- "Unable to request interrupt for device (err=%d).\n",
- ret);
+ dev_err(&pdev->dev, "failed to request interrupt: %d\n", ret);
goto disable_clk;
}
ret = rtc_register_device(info->rtc_dev);
if (ret) {
- dev_err(&pdev->dev, "Unable to register device (err=%d).\n",
- ret);
+ dev_err(&pdev->dev, "failed to register device: %d\n", ret);
goto disable_clk;
}
tegra_rtc_wait_while_busy(dev);
- /* only use ALARM0 as a wake source. */
+ /* only use ALARM0 as a wake source */
writel(0xffffffff, info->rtc_base + TEGRA_RTC_REG_INTR_STATUS);
writel(TEGRA_RTC_INTR_STATUS_SEC_ALARM0,
info->rtc_base + TEGRA_RTC_REG_INTR_MASK);
dev_vdbg(dev, "alarm sec = %d\n",
- readl(info->rtc_base + TEGRA_RTC_REG_SECONDS_ALARM0));
+ readl(info->rtc_base + TEGRA_RTC_REG_SECONDS_ALARM0));
- dev_vdbg(dev, "Suspend (device_may_wakeup=%d) irq:%d\n",
- device_may_wakeup(dev), info->tegra_rtc_irq);
+ dev_vdbg(dev, "Suspend (device_may_wakeup=%d) IRQ:%d\n",
+ device_may_wakeup(dev), info->tegra_rtc_irq);
- /* leave the alarms on as a wake source. */
+ /* leave the alarms on as a wake source */
if (device_may_wakeup(dev))
enable_irq_wake(info->tegra_rtc_irq);
struct tegra_rtc_info *info = dev_get_drvdata(dev);
dev_vdbg(dev, "Resume (device_may_wakeup=%d)\n",
- device_may_wakeup(dev));
- /* alarms were left on as a wake source, turn them off. */
+ device_may_wakeup(dev));
+
+ /* alarms were left on as a wake source, turn them off */
if (device_may_wakeup(dev))
disable_irq_wake(info->tegra_rtc_irq);
static void tegra_rtc_shutdown(struct platform_device *pdev)
{
- dev_vdbg(&pdev->dev, "disabling interrupts.\n");
+ dev_vdbg(&pdev->dev, "disabling interrupts\n");
tegra_rtc_alarm_irq_enable(&pdev->dev, 0);
}
-MODULE_ALIAS("platform:tegra_rtc");
static struct platform_driver tegra_rtc_driver = {
- .remove = tegra_rtc_remove,
- .shutdown = tegra_rtc_shutdown,
- .driver = {
- .name = "tegra_rtc",
+ .remove = tegra_rtc_remove,
+ .shutdown = tegra_rtc_shutdown,
+ .driver = {
+ .name = "tegra_rtc",
.of_match_table = tegra_rtc_dt_match,
- .pm = &tegra_rtc_pm_ops,
+ .pm = &tegra_rtc_pm_ops,
},
};
MODULE_AUTHOR("Jon Mayo <jmayo@nvidia.com>");
MODULE_DESCRIPTION("driver for Tegra internal RTC");
+MODULE_ALIAS("platform:tegra_rtc");
MODULE_LICENSE("GPL");
projects / platform / kernel / linux-rpi.git / commitdiff