[PATCH v4 1/2] arm64: dts: meson-g12b-odroid-n2: Enable RTC controller node

[Kevin Hilman]

Anand Moon <linux.amoon at gmail.com> writes:

> Enable RTC PCF8563 node on Odroid-N2 SBC, In order to
> support the RTC wakealarm feature for suspend and resume.
> Also assign an alias to the pcf8563 to rtc0 and meson-vrtc to rtc1
> timer device to prevent it being assigned to /dev/rtc0
> which disto userspace tools assume is a clock device.
>
> Cc: Neil Armstrong <narmstrong at baylibre.com>
> Cc: Kevin Hilman <khilman at baylibre.com>
> Suggested-by: Christian Hewitt <christianshewitt at gmail.com>
> Signed-off-by: Anand Moon <linux.amoon at gmail.com>
> ---
> Changes v4
> --Add gpio interrupt for GPIOAO.BIT7 as suggested by Neil.
> Changes v3
> --Drop the INI GPIOAO.BIT7 pinctrl.
> --Added missing RTC alias so that rtc get assigned correcly,
>   as suggested by Chris Hewitt.
> changes v2
> --Fix the missing INT (GPIOAO.BIT7) pinctrl.
> --Fix the missing rtcwakeup.
> --Drop the clock not required clock property by the PCF8563 driver.
> ---
>  .../boot/dts/amlogic/meson-g12b-odroid-n2.dts   | 17 +++++++++++++++++
>  1 file changed, 17 insertions(+)
>
> diff --git a/arch/arm64/boot/dts/amlogic/meson-g12b-odroid-n2.dts b/arch/arm64/boot/dts/amlogic/meson-g12b-odroid-n2.dts
> index 34fffa6d859d..3e2aaa6f48e5 100644
> --- a/arch/arm64/boot/dts/amlogic/meson-g12b-odroid-n2.dts
> +++ b/arch/arm64/boot/dts/amlogic/meson-g12b-odroid-n2.dts
> @@ -19,6 +19,8 @@ / {
>  	aliases {
>  		serial0 = &uart_AO;
>  		ethernet0 = ðmac;
> +		rtc0 = &rtc0;
> +		rtc1 = &vrtc;
>  	};
>  
>  	dioo2133: audio-amplifier-0 {
> @@ -477,6 +479,21 @@ hdmi_tx_tmds_out: endpoint {
>  	};
>  };
>  
> +&i2c3 {
> +	pinctrl-0 = <&i2c3_sda_a_pins>, <&i2c3_sck_a_pins>;
> +	pinctrl-names = "default";
> +	status = "okay";
> +
> +	rtc0: rtc at 51 {
> +		reg = <0x51>;
> +		compatible = "nxp,pcf8563";
> +		/* RTC INT */
> +		interrupts = <GPIOAO_7 IRQ_TYPE_LEVEL_LOW>;
> +		interrupt-parent = <&gpio_intc>;
> +		wakeup-source;
> +	};
> +};

There's still no pinctrl definition for the GPIO pin being used as the
IRQ.  It looks like you discussed this with Martin and he pointed you in
the right direction in your v3 series, but I don't see it in this
patch.  

You can see the GPIOs that the kernel knows about using the GPIO
debugfs.  For example:

/ # cat /sys/kernel/debug/gpio                                                                                                            
gpiochip1: GPIOs 412-426, parent: platform/ff800000.sys-ctrl:pinctrl at 14, aobus-banks:                                                     
 gpio-414 (                    |enable              ) out lo                                                                              
 gpio-420 (                    |regulator-tflash_vdd) out hi                                                                              
 gpio-421 (                    |TF_IO               ) out lo                           
 gpio-423 (                    |n2:blue             ) out lo                  
                                                                                           
gpiochip0: GPIOs 427-511, parent: platform/ff634400.bus:pinctrl at 40, periphs-banks:
 gpio-442 (                    |PHY reset           ) out hi ACTIVE LOW                    
 gpio-447 (                    |usb-hub-reset       ) out hi              
 gpio-448 (                    |regulator-hub_5v    ) out hi                               
 gpio-449 (                    |regulator-usb_pwr_en) out lo
 gpio-464 (                    |reset               ) out hi ACTIVE LOW              
 gpio-474 (                    |cd                  ) in  lo ACTIVE LOW


Also, I tested this on my odroid-n2, and it does not fully wakeup[1].
At the end of the log, you can see the "resume rate" of the big and
little cores, which suggests that the SoC has woken and trying to
resume, but it never makes it back to the kernel.

Could you be more specific with exactly what u-boot you're running
(mainline version and Khadas version.)

I'm running an older version of mainline u-boot:
U-Boot 2019.07-rc3-00029-g47bebaa4a3-dirty (Jun 04 2019 - 17:16:32 +0200) odroid-n2 

Kevin


[1]
/ # dmesg |grep -i rtc                                           
[   14.799773] meson-vrtc ff8000a8.rtc: registered as rtc1   
[   14.871365] rtc-pcf8563 0-0051: low voltage detected, date/time is not reliable.
[   14.871519] rtc-pcf8563 0-0051: registered as rtc0
[   14.873536] rtc-pcf8563 0-0051: low voltage detected, date/time is not reliable.
[   14.886474] rtc-pcf8563 0-0051: hctosys: unable to read the hardware clock
/ # rtcwake -d rtc0 -m mem -s5                              
rtcwake: assuming RTC uses UTC ...                          
rtcwake: wakeup from "mem" using rtc0 at Mon Aug 31 19:58:15 2020
[  119.297633] PM: suspend entry (deep)
[  119.297722] Filesystems sync: 0.000 seconds
[  119.300330] Freezing user space processes ... (elapsed 0.003 seconds) done.
[  119.306667] OOM killer disabled.
[  119.309828] Freezing remaining freezable tasks ... (elapsed 0.001 seconds) done.
[  119.317184] printk: Suspending console(s) (use no_console_suspend to debug)
bl30 get wakeup sources!
process command 00000006
bl30 enter suspend!
Little core clk suspend rate 1200000000
Big core clk suspend rate 24000000
store restore gp0 pll
suspend_counter: 1
Enter ddr suspend
ddr suspend time: 17us
alarm=0S
process command 00000001
cec ver:2018/04/19
CEC cfg:0x0000
WAKEUP GPIO cfg:0x00000000
use vddee new table!
WAKEUP GPIO FAIL - invalid key
fffffe71
use vddee new table!
exit_reason:0x03
Enter ddr resume
ddr resume time: 125us
store restore gp0 pll
cfg15 3b00000
cfg15 33b00000
Little core clk resume rate 1200000000
Big core clk resume rate 50000000