On Sun, 2021-10-24 at 10:32 +0200, Hans de Goede wrote: > Hi, > > [...] > > <note going a bit offtopic from atomisp here> > > Friday I've resized the Android data partition on my Mi Pad 2 Android, > 16G eMMC model and installed Fedora 35 in the free space. > > And yesterday I've been poking at the Mi Pad 2 the entire day, > both under Fedora and under the original Android install to figure > out which chips there are and how they are used, etc. This has > diverted me from looking into atomisp2 stuff, but it was fun :) > > I've also managed to make the i915 driver work. It still gives one > warning during boot which I need to look into. But it works now. > ATM my i915 fix is just a hack. I plan to turn it into something > which I hope I can get upstream, I'll Cc you (Tsuchiya) on the > upstream submission of the i915 submission. Thank you! I just tried your patch and now mipad2 can boot with GPU! So, I tried if I can reproduce touchscreen issue with atomisp, but there was no such issue. Touchscreen works regardless of atomisp drivers. I guess this is maybe a PMIC difference (mipad2/wcove and surface3/ccove). > I've also figured out all the other chips used in the Mi Pad 2 > and I believe I should be able to get things battery monitoring > and switching the USB plug between host <-> device mode to work > without too much issues (but it will take some time). This is > all pretty similar to all the special handling which I've already > added to the kernel for the GPD win / pocket devices which also > use the CHT Whiskey Cove PMIC. Thanks. I haven't looked into anything other than atomisp yet, so I can't comment anything but it's really interesting to see how drivers are developed :-) > Here are my notes about all the non standard chips used in the > Mi Pad 2: > > PMIC/charger/fuel-gauge: > -The Type-C connector is used as / wired up as a regular micro-USB connector > > -There is a Cherry Trail Whiskey Cove PMIC on the I2C7 i2c_designware ctrl > -This is used for ID pin detection > -Charger-type detection does not work though, because the USB-2 data-lines are > not connected to it > -The 2 GPIOs which are used to enable an external V5 boost converter for > Vbus resp Vconn on other designs are both configured as inputs (register value 0x18) > -The extcon-intel-cht-wc driver should control the USB mux according to the > ID pin, identically to how the extcon-axp288 code does this > -The extcon-intel-cht-wc driver should control the Vboost converter in the > bq25890 charger IC based on the ID pin > > -There is a bq25890 charger hanging from the CHT-WC PMIC charger I2C-bus at addr 0x6a > -At boot the BIOS clears bit 4 of register 3, disabling charging so the device > will still be powered from an external supply, but it will not charge! > Linux needs to fix this up > -This charger is connected to the USB-2 data-lines and automatically sets its > input-current-limit based on the detected charger > -Bit 5 of register 3 controls the Vboost converter for sending 5V to attached > USB-devices this bit needs to be controller by Linux based on the ID pin > detection from the PMIC. The BIOS does leave this enabled when booting with > a USB-device plugged in. > > -There is a BQ27520 fuel-gauge at address 0x55 of the I2C1 i2c_designware ctrl > > I2C1: addr 0x55 BQ27520 fuel-gauge > > I2C2: addr 0x0e unknown > I2C2: addr 0x1b Realtek 5659 codec ? (not detected by i2cdetect) > I2C2: addr 0x2c TI lp855x backlight controller: > https://github.com/MiCode/Xiaomi_Kernel_OpenSource/blob/latte-l-oss/drivers/video/backlight/lp855x_bl.c > I2C2: addr 0x34 NXP9890 audio amplifier > I2C2: addr 0x37 NXP9890 audio amplifier > I2C2: addr 0x3e unknown > > I2C3: addr 0x30 KTD2026 RGB LED driver, controlling the status LED > https://github.com/MiCode/Xiaomi_Kernel_OpenSource/blob/latte-l-oss/drivers/leds/leds-ktd2026.c > > I2C4: addr 0x36? OVTI5693 camera sensor > I2C4: addr 0x37 t3ka3 camera sensor > > I2C5: addr 0x5a Motor DRV2604 Driver ? the tablet has no haptic feedback motor! > Also nothing seen here by i2c-detect, probably bogus This must be a motor for the world-facing camera! I see "DW9761" in DSDT. Currently, I have no idea if motors are working with the upstreamed atomisp because there is no userspace driver for Linux that can use motors. Regards, Tsuchiya Yuto > I2C6: addr 0x38 FTSC touchscreen > > I2C7: PMIC bus > > -TPS61158: LED controller for menu keys LEDS, driven by PWM controller, max brightness > 80/255 !!!! > https://github.com/MiCode/Xiaomi_Kernel_OpenSource/blob/latte-l-oss/drivers/leds/leds-tps61158.c > Android behavior: light up menu keys for 5 seconds on any human input: > -Write a special HID driver for mainline linux to fix the key-events send by the > touchscreen and to light up the keys for 5 seconds on any HID input reports > > -Sensors (accel, als) through hid-ishtp > > -Panel 1536x2048 on card0-DSI-1 > https://bugs.freedesktop.org/show_bug.cgi?id=108714 > > -DSDT: Android: OSID == 0x04, Windows OSID == 0x01 > > Regards, > > Hans
