[LEDE-DEV] [PATCH 2/2] mvebu: Add Solidrun RTC init patch.

Rosen Penev rosenp at gmail.com
Sat Mar 17 09:09:57 PDT 2018


On Sat, Mar 17, 2018 at 6:24 AM, Hauke Mehrtens <hauke at hauke-m.de> wrote:
> On 03/16/2018 01:53 AM, Rosen Penev wrote:
>> 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.
>
> Please line break your commit message.
>
> Will you send this patch upstream?
No. I have no experience with upstream at all.
>
> Is the RTC in the turris omnia battery backed and is a crystal connected
> to it? There are a lot of problems with the RTC in the Linksys devices.
Yes there is a crystal and a a battery. As of 62 hours, it is keeping
time correctly.
>
> Hauke
>
>>
>> Signed-off-by: Rosen Penev <rosenp at gmail.com>
>> ---
>>  .../mvebu/patches-4.14/421-rtc-initialize.patch    | 70 ++++++++++++++++++++++
>>  1 file changed, 70 insertions(+)
>>  create mode 100644 target/linux/mvebu/patches-4.14/421-rtc-initialize.patch
>>
>> 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..b6b96c985c
>> --- /dev/null
>> +++ b/target/linux/mvebu/patches-4.14/421-rtc-initialize.patch
>> @@ -0,0 +1,70 @@
>> +--- a/drivers/rtc/rtc-armada38x.c    2017-12-11 18:32:22.329841869 +0200
>> ++++ b/drivers/rtc/rtc-armada38x.c    2017-12-11 19:01:40.677854645 +0200
>> +@@ -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 @@
>> +     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 @@
>> +     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 @@
>> +     .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 @@
>> +             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;
>> + }
>> +
>>
>



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