Hi Henrik >-----Original Message----- >From: Henrik Grimler [mailto:henrik@xxxxxxxxxx] >Sent: Monday, January 17, 2022 10:28 PM >To: Alim Akhtar <alim.akhtar@xxxxxxxxxxx> >Cc: 'Krzysztof Kozlowski' <krzysztof.kozlowski@xxxxxxxxxxxxx>; >semen.protsenko@xxxxxxxxxx; virag.david003@xxxxxxxxx; >martin.juecker@xxxxxxxxx; cw00.choi@xxxxxxxxxxx; >m.szyprowski@xxxxxxxxxxx; robh+dt@xxxxxxxxxx; >devicetree@xxxxxxxxxxxxxxx; linux-samsung-soc@xxxxxxxxxxxxxxx; linux-arm- >kernel@xxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; >~postmarketos/upstreaming@xxxxxxxxxxx >Subject: Re: [PATCH v3 3/3] ARM: dts: Add support for Samsung Chagall WiFi > >Hi Alim, > >> >> > +/* External sdcard */ >> >> > +&mmc_2 { >> >> > + status = "okay"; >> >> > + bus-width = <4>; >> >> > + cap-sd-highspeed; >> >> > + card-detect-delay = <200>; >> >> > + pinctrl-0 = <&sd2_clk &sd2_cmd &mmc2_cd &sd2_bus1 >&sd2_bus4>; >> >> > + pinctrl-names = "default"; >> >> > + samsung,dw-mshc-ciu-div = <3>; >> >> > + samsung,dw-mshc-ddr-timing = <0 2>; >> >> > + samsung,dw-mshc-sdr-timing = <0 4>; >> >> > + sd-uhs-sdr50; >> >> > + vmmc-supply = <&ldo19_reg>; >> >> > + vqmmc-supply = <&ldo13_reg>; >> >> > +}; >> >> > + >> >> > +&pinctrl_0 { >> >> > + mmc2_cd: sd2-cd-pins { >> >> > + samsung,pins = "gpx2-4"; >> >> >> >> Interesting... I looked at vendor sources to board-chagall and >> >> standard pin gpc2-2 is mentioned as PULL down and not-connected >> >comment. >> >> >> >> gpx2-4 seems not mentioned at all, unless other board files are >> >> actually used. >> > >> >Gpio seems to be spread out. GPIO_T_FLASH_DETECT is defined as gpx2-4 >> >in board-universal5420-mmc.c, and then used for card detection. >> >(Looking at it now again I see that write protection through sd2_wp >> >should also be supported for mmc_2, can add that in next patch set.) >> > >> Card detect pin is generally a special function (dedicated pin) pin, >> directly connected from SoC to card external slot. >> And for exynos5420 it is gpc2-2 as pointed by Krzysztof. > >gpio/pinctrl is still not my area of expertise so your feedback is greatly >appreciated! > >gpc2-2 does not seem to be the card-detect pin for these tablets. If I add >sd2_cd to pinctrl-0 above I am unable to use the sdcard at all, instead dmesg is >filled with repeating messages like: > >[ 18.669050] mmc_host mmc1: Bus speed (slot 0) = 50000000Hz (slot req >300000Hz, actual 297619HZ div = 84) [ 18.703711] mmc_host mmc1: Bus speed >(slot 0) = 50000000Hz (slot req 200000Hz, actual 200000HZ div = 125) [ >18.737167] mmc_host mmc1: Bus speed (slot 0) = 50000000Hz (slot req >100000Hz, actual 100000HZ div = 250) [ 19.058352] mmc_host mmc1: Bus >speed (slot 0) = 50000000Hz (slot req 400000Hz, actual 396825HZ div = 63) [ >19.093037] mmc_host mmc1: Bus speed (slot 0) = 50000000Hz (slot req >300000Hz, actual 297619HZ div = 84) [ 19.127701] mmc_host mmc1: Bus speed >(slot 0) = 50000000Hz (slot req 200000Hz, actual 200000HZ div = 125) [ >19.162380] mmc_host mmc1: Bus speed (slot 0) = 50000000Hz (slot req >100000Hz, actual 100000HZ div = 250) > >gpx2-4 on the other hand switches state when an sdcard is inserted or >removed. After exporting relevant pins I have, with the card >inserted: > ># grep -A 2 gpx2 /sys/kernel/debug/gpio >gpiochip3: GPIOs 24-31, parent: platform/13400000.pinctrl, gpx2: > gpio-26 ( |Power ) in hi IRQ ACTIVE LOW > gpio-28 ( |sysfs ) in lo > >and when removed gpx2-4 changes to high: > >gpiochip3: GPIOs 24-31, parent: platform/13400000.pinctrl, gpx2: > gpio-26 ( |Power ) in hi IRQ ACTIVE LOW > gpio-28 ( |sysfs ) in hi > >All the gpc2 pins are low no matter if sdcard is inserted or removed: > >gpiochip7: GPIOs 56-62, parent: platform/13410000.pinctrl, gpc2: > gpio-56 ( |sysfs ) in lo > gpio-57 ( |sysfs ) in lo > gpio-58 ( |sysfs ) in lo > gpio-59 ( |sysfs ) in lo > gpio-60 ( |sysfs ) in lo > gpio-61 ( |sysfs ) in lo > gpio-62 ( |sysfs ) in lo > >That being said, I am not sure if it is working properly: > >> Also PIN_FUNC_2 for gpx2-4 indicate that it is wakeup_int2 function. >> Do you get a card detect interrupt when removing and inserting the >> card to the card slot? > This is the confirmation that this board does not uses gpc2-2 but gpx2-4. Thanks for detailed log. >(What is the best way to check this?) I don't get any irq related messages in Probably if you are interested, you can enable few debug in dw-mmc driver to check a message like "card is present" etc. >dmesg, and I don't see any changes in /proc/interrupts if tracked with >something like `watch -n1 "cat /proc/interrupts"` when card is removed or >inserted, so seems likely that pin config is wrong. >All I can find in vendor kernel for this device is that pull config is set to >S3C_GPIO_PULL_NONE [1]. For some of the sibling tablets the pin is >configured as {S3C_GPIO_INPUT, GPIO_LV_N, S3C_GPIO_PULL_NONE} [2] >though, which I think should correspond to having: > >mmc2_cd: mmc2-cd-pins { > samsung,pins = "gpx2-4"; > samsung,pin-function = <EXYNOS_PIN_FUNC_INPUT>; > samsung,pin-pud = <EXYNOS_PIN_PULL_NONE>; > samsung,pin-drv = <EXYNOS5420_PIN_DRV_LV3>; }; > >Changing to that does not seem to change anything though, I don't get any >interrupt, or any messages in dmesg, when inserting or removing the sdcard. > >> Also to avoid confusion, probably you can change the node name as >"mmc2_cd: >> mmc2-cd-pins" >> (as sd2-cd-pins is gpc2-2 for this SoC) > >Thanks, will fix in a v4 (after discussions here are settled). > I am convinced that gpc2-2 is not used for card detect for this board. So no other query on this patch. Thanks >[1] https://protect2.fireeye.com/v1/url?k=bba823ae-dad5cbe9-bba9a8e1- >74fe485fff30-b4ccbbe9776f501d&q=1&e=9951c78c-16c8-449e-913b- >d4d1f1f9bb6b&u=https%3A%2F%2Fgithub.com%2Fexynos5420%2Fandroid_k >ernel_samsung_exynos5420%2Fblob%2Flineage- >17.1%2Farch%2Farm%2Fmach-exynos%2Fboard-universal5420- >mmc.c%23L388 >[2] https://protect2.fireeye.com/v1/url?k=97465c6e-f63bb429-9747d721- >74fe485fff30-4111389a6d2b68b4&q=1&e=9951c78c-16c8-449e-913b- >d4d1f1f9bb6b&u=https%3A%2F%2Fgithub.com%2Fexynos5420%2Fandroid_k >ernel_samsung_exynos5420%2Fblob%2Flineage- >17.1%2Farch%2Farm%2Fmach-exynos%2Fboard-n1-gpio.c%23L119 > >Best regards, >Henrik Grimler
