diff options
Diffstat (limited to 'target/linux/mvebu/patches-4.14/421-rtc-armada38x-reset-after-rtc-power-loss.patch')
| -rw-r--r-- | target/linux/mvebu/patches-4.14/421-rtc-armada38x-reset-after-rtc-power-loss.patch | 78 |
1 files changed, 78 insertions, 0 deletions
diff --git a/target/linux/mvebu/patches-4.14/421-rtc-armada38x-reset-after-rtc-power-loss.patch b/target/linux/mvebu/patches-4.14/421-rtc-armada38x-reset-after-rtc-power-loss.patch new file mode 100644 index 0000000000..e9291c456f --- /dev/null +++ b/target/linux/mvebu/patches-4.14/421-rtc-armada38x-reset-after-rtc-power-loss.patch @@ -0,0 +1,78 @@ +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 + |