You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
79 lines
2.5 KiB
79 lines
2.5 KiB
6 years ago
|
From 1a990fefb641398fb580a0ea0be99b0ff27cbb9b Mon Sep 17 00:00:00 2001
|
||
|
|
From: Baruch Siach <baruch@tkos.co.il>
|
||
|
|
Date: Thu, 21 Jun 2018 20:40:23 +0300
|
||
|
|
Subject: [PATCH] rtc: armada38x: reset after rtc power loss
|
||
|
|
|
||
|
|
When the RTC block looses power it needs a reset sequence to make it
|
||
|
|
usable again. Otherwise, writes to the time register have no effect.
|
||
|
|
|
||
|
|
This reset sequence combines information from the mvebu_rtc driver in
|
||
|
|
the Marvell provided U-Boot, and the SolidRun provided U-Boot repo.
|
||
|
|
|
||
|
|
Tested on the Armada 388 based SolidRun Clearfog Base.
|
||
|
|
|
||
|
|
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
|
||
|
|
Acked-by: Gregory CLEMENT <gregory.clement@bootlin.com>
|
||
|
|
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
|
||
|
|
---
|
||
|
|
drivers/rtc/rtc-armada38x.c | 23 +++++++++++++++++++++++
|
||
|
|
1 file changed, 23 insertions(+)
|
||
|
|
|
||
|
|
diff --git a/drivers/rtc/rtc-armada38x.c b/drivers/rtc/rtc-armada38x.c
|
||
|
|
index 1e4978c..bde53c8c 100644
|
||
|
|
--- a/drivers/rtc/rtc-armada38x.c
|
||
|
|
+++ b/drivers/rtc/rtc-armada38x.c
|
||
|
|
@@ -30,6 +30,8 @@
|
||
|
|
#define RTC_IRQ_FREQ_1HZ BIT(2)
|
||
|
|
#define RTC_CCR 0x18
|
||
|
|
#define RTC_CCR_MODE BIT(15)
|
||
|
|
+#define RTC_CONF_TEST 0x1C
|
||
|
|
+#define RTC_NOMINAL_TIMING BIT(13)
|
||
|
|
|
||
|
|
#define RTC_TIME 0xC
|
||
|
|
#define RTC_ALARM1 0x10
|
||
|
|
@@ -75,6 +77,7 @@ struct armada38x_rtc {
|
||
|
|
void __iomem *regs_soc;
|
||
|
|
spinlock_t lock;
|
||
|
|
int irq;
|
||
|
|
+ bool initialized;
|
||
|
|
struct value_to_freq *val_to_freq;
|
||
|
|
struct armada38x_rtc_data *data;
|
||
|
|
};
|
||
|
|
@@ -226,6 +229,23 @@ static int armada38x_rtc_read_time(struct device *dev, struct rtc_time *tm)
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
+static void armada38x_rtc_reset(struct armada38x_rtc *rtc)
|
||
|
|
+{
|
||
|
|
+ u32 reg;
|
||
|
|
+
|
||
|
|
+ reg = rtc->data->read_rtc_reg(rtc, RTC_CONF_TEST);
|
||
|
|
+ /* If bits [7:0] are non-zero, assume RTC was uninitialized */
|
||
|
|
+ if (reg & 0xff) {
|
||
|
|
+ rtc_delayed_write(0, rtc, RTC_CONF_TEST);
|
||
|
|
+ msleep(500); /* Oscillator startup time */
|
||
|
|
+ rtc_delayed_write(0, rtc, RTC_TIME);
|
||
|
|
+ rtc_delayed_write(SOC_RTC_ALARM1 | SOC_RTC_ALARM2, rtc,
|
||
|
|
+ RTC_STATUS);
|
||
|
|
+ rtc_delayed_write(RTC_NOMINAL_TIMING, rtc, RTC_CCR);
|
||
|
|
+ }
|
||
|
|
+ rtc->initialized = true;
|
||
|
|
+}
|
||
|
|
+
|
||
|
|
static int armada38x_rtc_set_time(struct device *dev, struct rtc_time *tm)
|
||
|
|
{
|
||
|
|
struct armada38x_rtc *rtc = dev_get_drvdata(dev);
|
||
|
|
@@ -237,6 +257,9 @@ static int armada38x_rtc_set_time(struct device *dev, struct rtc_time *tm)
|
||
|
|
if (ret)
|
||
|
|
goto out;
|
||
|
|
|
||
|
|
+ if (!rtc->initialized)
|
||
|
|
+ armada38x_rtc_reset(rtc);
|
||
|
|
+
|
||
|
|
spin_lock_irqsave(&rtc->lock, flags);
|
||
|
|
rtc_delayed_write(time, rtc, RTC_TIME);
|
||
|
|
spin_unlock_irqrestore(&rtc->lock, flags);
|
||
|
|
--
|
||
|
|
2.7.4
|
||
|
|
|