diff options
Diffstat (limited to 'target/linux/mvebu/patches-4.14/421-rtc-initialize.patch')
| -rw-r--r-- | target/linux/mvebu/patches-4.14/421-rtc-initialize.patch | 74 |
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; + } + |