On Sat, Feb 1, 2020 at 5:10 PM Adam Van Ymeren [off-list ref] wrote:

On 2020-02-01 12:46 p.m., Robin Murphy wrote:

quoted

On 2020-02-01 3:41 pm, Adam Van Ymeren wrote:

quoted

On 2020-02-01 5:51 a.m., Robin Murphy wrote:

quoted

Hi Adam,

On 2020-01-31 11:38 pm, Adam Van Ymeren wrote:

quoted

With this change the kernel successfully finds the SD Card and can
load
a rootfs from it.  Tested on hardware.

Signed-off-by: Adam Van Ymeren <redacted>

diff -uprN -X linux-5.5/Documentation/dontdiff
linux-5.5-orig/arch/arm64/boot/dts/rockchip/rk3328-roc-cc.dts
linux-5.5/arch/arm64/boot/dts/rockchip/rk3328-roc-cc.dts

--- linux-5.5-orig/arch/arm64/boot/dts/rockchip/rk3328-roc-cc.dts

2020-01-26 19:23:03.000000000 -0500

+++ linux-5.5/arch/arm64/boot/dts/rockchip/rk3328-roc-cc.dts

2020-01-31 16:26:35.377075419 -0500

@@ -44,7 +44,7 @@
         vcc_sdio: sdmmcio-regulator {
           compatible = "regulator-gpio";
-        gpios = <&grf_gpio 0 GPIO_ACTIVE_HIGH>;
+        gpios = <&gpio0 RK_PD1 GPIO_ACTIVE_HIGH>;

Given that the RK3328 datasheet has no mention of GPIO0_D1 existing at
all, how sure are you that this is correct - have you tested cards in
both 3.3V and 1.8V (UHS-1) signalling modes?

The ROC-RK3328-CC schematics show GPIO_MUTE being used to bias the
feedback pin of an adjustable regulator supplying the SDMMC0 I/O
domain, so it seems more likely that the pin is correct but the states
(or the polarity) are backwards.

Hmm yeah after reading the schematics this doesn't make sense.  I took
it from the vendors source tree[1], and it definitely allowed my system
to boot when it wouldn't before, but I only tried a 3.3V card.  I'll try
just changing the polarity.  I'll also find a UHS-1 card and test that,
any advice on how to verify that it's running in the 1.8V mode?

My preferred method is to stick a meter on either the uSD socket pins
or the regulator itself and wiggle the GPIO from userspace, but
preferably only if the board can run without a card inserted.

That said, I just suddenly remembered about regulator GPIOs being
quirky for legacy ABI reasons - I'm now 99% sure that you should
simply need to add the "enable-active-high" property to make it
actually work as expected.

Whelp I did a whole bunch of tracing and debugging only to realize that
I didn't have CONFIG_GPIO_SYSCON enabled, so big suprise the gpio-syscon
driver needed for grf-gpio never came online.  After turning that on I get

[    1.277115] mmc_host mmc1: Bus speed (slot 0) = 400000Hz (slot req
400000Hz, actual 400000HZ div = 0)

in my dmesg, which is more than I used to get.  However it fails to
detect the SDCard.  I tried with and without enable-active-high; on the
sdmmcio-regulator entry, neither seemed to make a difference.  I'll do
some more debugging in a bit, its always possible I did something stupid
like use the wrong .dtb file (or build without CONFIG_GPIO_SYSCON).

I'm interested in this, since I've encountered some oddities with the
sdcard on this board.
With the recent addition of support for ddr4 tpl init in u-boot I
started playing with it again.
I couldn't get the sdcard to detect leaving tpl into spl, causing a
boot failure.
The exact same image works when flashed to the emmc though.

Once we are in the kernel the sdcard detects fine.

I noticed u-boot doesn't have a grf-gpio driver, so the 3.3v/1.8v
regulator is unavailable.

root@firefly:/sys/kernel/debug/mmc1# cat ios
clock:          150000000 Hz
actual clock:   150000000 Hz
vdd:            21 (3.3 ~ 3.4 V)
bus mode:       2 (push-pull)
chip select:    0 (don't care)
power mode:     2 (on)
bus width:      2 (4 bits)
timing spec:    6 (sd uhs SDR104)
signal voltage: 1 (1.80 V)
driver type:    0 (driver type B)

root@firefly:/sys/kernel/debug# cat gpio
gpiochip0: GPIOs 0-31, parent: platform/pinctrl, gpio0:
 gpio-0   (                    |vcc-host-5v-regulato) out hi
 gpio-30  (                    |sdmmc-regulator     ) out lo ACTIVE LOW

gpiochip1: GPIOs 32-63, parent: platform/pinctrl, gpio1:
 gpio-50  (                    |snps,reset          ) out hi ACTIVE LOW
 gpio-58  (                    |vcc-host1-5v-regulat) out hi

gpiochip2: GPIOs 64-95, parent: platform/pinctrl, gpio2:

gpiochip3: GPIOs 96-127, parent: platform/pinctrl, gpio3:

gpiochip5: GPIOs 509-510, parent: platform/rk805-pinctrl, rk805-gpio, can sleep:
 gpio-509 (                    |?                   ) out hi ACTIVE LOW
 gpio-510 (                    |?                   ) out hi ACTIVE LOW

gpiochip4: GPIOs 511-511, parent: platform/ff100000.syscon:grf-gpio,
ff100000.syscon:grf-gpio:
 gpio-511 (                    |vcc_sdio            ) out hi

Thanks again!

-Adam

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