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-rw-r--r--target/linux/mvebu/patches-4.14/421-rtc-initialize.patch74
1 files changed, 74 insertions, 0 deletions
diff --git a/target/linux/mvebu/patches-4.14/421-rtc-initialize.patch b/target/linux/mvebu/patches-4.14/421-rtc-initialize.patch
new file mode 100644
index 0000000000..47a5acc70d
--- /dev/null
+++ b/target/linux/mvebu/patches-4.14/421-rtc-initialize.patch
@@ -0,0 +1,74 @@
+Some boards like the Turris Omnia have an RTC chip that does not get
+initialized. Initializing the RTC at the driver level helps get rid of
+bootloader hacks that write special register values.
+
+--- a/drivers/rtc/rtc-armada38x.c
++++ b/drivers/rtc/rtc-armada38x.c
+@@ -30,6 +30,9 @@
+ #define RTC_IRQ_FREQ_1HZ BIT(2)
+ #define RTC_CCR 0x18
+ #define RTC_CCR_MODE BIT(15)
++#define RTC_CCR_NORMAL_PPB 0x2000
++#define RTC_TEST_CONF 0x1c
++#define RTC_TEST_CONF_MASK 0xff
+
+ #define RTC_TIME 0xC
+ #define RTC_ALARM1 0x10
+@@ -91,6 +94,7 @@ struct armada38x_rtc_data {
+ void (*clear_isr)(struct armada38x_rtc *rtc);
+ void (*unmask_interrupt)(struct armada38x_rtc *rtc);
+ u32 alarm;
++ void (*init_rtc)(struct armada38x_rtc *rtc);
+ };
+
+ /*
+@@ -202,6 +206,23 @@ static void armada38x_unmask_interrupt(s
+ writel(val | SOC_RTC_ALARM1_MASK, rtc->regs_soc + SOC_RTC_INTERRUPT);
+ }
+
++static void armada38x_rtc_init(struct armada38x_rtc *rtc)
++{
++ u32 reg;
++
++ /* Test RTC test configuration register bits [7:0] */
++ reg = readl(rtc->regs + RTC_TEST_CONF);
++ /* If bits [7:0] are non-zero, assume RTC was uninitialized */
++ if (reg & RTC_TEST_CONF_MASK) {
++ rtc_delayed_write(0, rtc, RTC_TEST_CONF);
++ rtc_delayed_write(0, rtc, RTC_TIME);
++ rtc_delayed_write((RTC_STATUS_ALARM1 | RTC_STATUS_ALARM2),
++ rtc, RTC_STATUS);
++ rtc_delayed_write(RTC_CCR_NORMAL_PPB, rtc, RTC_CCR);
++ }
++ return;
++}
++
+ static void armada8k_clear_isr(struct armada38x_rtc *rtc)
+ {
+ writel(RTC_8K_ALARM2, rtc->regs_soc + RTC_8K_ISR);
+@@ -464,6 +485,7 @@ static const struct armada38x_rtc_data a
+ .clear_isr = armada38x_clear_isr,
+ .unmask_interrupt = armada38x_unmask_interrupt,
+ .alarm = ALARM1,
++ .init_rtc = armada38x_rtc_init,
+ };
+
+ static const struct armada38x_rtc_data armada8k_data = {
+@@ -558,6 +580,17 @@ static __init int armada38x_rtc_probe(st
+ dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret);
+ return ret;
+ }
++
++ /*
++ * Try to detect if RTC is in uninitialized state.
++ * It is not definitive to know if the RTC is in an uninialized state or not,
++ * but the following call will read some bits in the RTC unit and guess if
++ * if it's in that state, and accordingly set it to sane default values.
++ */
++ if (rtc->data->init_rtc) {
++ rtc->data->init_rtc(rtc);
++ }
++
+ return 0;
+ }
+