Difference between revisions of "CI20 upstream"

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GPU drivers rely on userland binaries and kernel module sources. The work to move to a [https://en.wikipedia.org/wiki/Direct_Rendering_Infrastructure DRI] based system is on-going at IMG. Until the drivers are updated, using the GPU (openGL etc) will not be possible.
 
GPU drivers rely on userland binaries and kernel module sources. The work to move to a [https://en.wikipedia.org/wiki/Direct_Rendering_Infrastructure DRI] based system is on-going at IMG. Until the drivers are updated, using the GPU (openGL etc) will not be possible.
  
For normal usage, Xorg and framebuffer drivers do work. The default xorg.conf is configured to load the PowerVR module. Move that somewhere else/keep a copy. And use this [https://github.com/ZubairLK/ci20_other_files/blob/master/xorg.conf.fbdev xorg.conf]  
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For normal usage, Xorg and framebuffer drivers do work. The default xorg.conf is configured to load the PowerVR module. Keep a copy of that somewhere else and use this [https://github.com/ZubairLK/ci20_other_files/blob/master/xorg.conf.fbdev xorg.conf]  
  
 
Note: Rename to xorg.conf. Don't leave it named xorg.conf.fbdev.
 
Note: Rename to xorg.conf. Don't leave it named xorg.conf.fbdev.

Revision as of 04:00, 2 July 2015

This page contains details about the latest kernel branch running on the CI20.

It will be periodically updated to keep up to speed with the latest.

The current branch tracking mainline 3.18.3

https://github.com/MIPS/CI20_linux

Status of Linux Kernel Drivers

Overview

The CI20 uses the Ingenic JZ4780 SoC. Ingenic provided a 3.0.8 kernel with reasonable support for most peripherals on the JZ4780. However, IMGTEC has reworked many drivers and forward ported others.

Ingenic produce another SoC called the JZ4740. This SoC has many similarities to the JZ4780 and many of its drivers are in the mainline kernel, although some are rather outdated. With this in mind, the best practice would be to augment the JZ4740 drivers to work with the JZ4780.

The 3.16 branch was created to run the CI20 on a more recent kernel with the aforementioned similarities in mind. There was some work done on consolidation to use the existing JZ4740 drivers. But the core SoC parts were still disjoint.

After collaboration with the kernel community working on JZ4740, JZ4770, JZ4780. 3.18 was rewritten with heavy emphasis on consolidation of the core SoC driver. The resulting core patches are in-flight.

There is still lots of work to be done, so please do contribute to kernel development. We are very welcoming and friendly on #ci20 chatroom and the mailing list

Core

In-flight patch series for jz4780 core support in kernel can be seen here

http://www.spinics.net/lists/mips/msg55258.html
Name State Path Notes 3.0.8 Notes 3.16 Notes 3.18 +
Clocks Works drivers/clk/jz47xx Could have common drivers/clk/ingenic for all SoCs with SoC specific binding using common components(?) Uses common clock framework with jz4740. Intended for upstream
CPUfreq 4770 has [1], but clock infrastructure is different. Ingenic kernel had [2] for 4780. Not ported to 3.16 yet.
Device Tree Mostly N/A Parsed on boot, but compiled into the kernel. Would be good to allow it to be passed from the bootloader. DT for jz4740 as well
DMA Mostly drivers/dma/dma-jz4780.c needs combining into dma-jz4740. Works, just missing priority support See [3]
GPIO Works drivers/pinctrl/pinctrl-jz4780.c should perhaps be in drivers/gpio/ (?)
Hotplug
IRQ Controller drivers/irqchip/irq-jz4780.c Very similar between SoCs (4740 has one bank, 60,70,80 has two banks) Consolidated work in 3.18 headed upstream
MXU Context
PinCtrl Mostly drivers/pinctrl/pinctrl-jz4780.c N/A Differs between SoCs. Functional, may need DT binding changes based on feedback from upstream. See also pinctrl-jz4770.c.
Power Controller (LPCR Register)
Power Off & Reset Works
RTC Works drivers/rtc/rtc-jz4740.c Consolidated with jz4740 Consolidated with jz4740
SMP Works Works Works
Watchdog Works Consolidated with jz4740

Peripheral drivers

Name State Path Notes 3.0.8 Notes 3.16 Notes 3.18+
ADC WIP Check branches on https://github.com/ZubairLK/CI20_linux
Audio (ALSA) Works Check patches on https://groups.google.com/forum/#!forum/mips-creator-ci20-dev Works. Uses jz4740 drivers with patches. i2s parts upstreamed. See [4] and [5]
Camera
Efuse Works drivers/misc/jz_efuse.c Works. Can read chip/serial id. Not linked with dm9000 for mac address. Upstream might face issues as yet another misc driver for eeprom. Efuse might need a subsystem talk etc
Ethernet Works drivers/net/ethernet/davicom/dm9000.c Requires regulator and reset GPIO support, see [6]. Patch upstreamed. See [7]
GPU External Kernel Module Works WIP. Requires major overhaul as kernel layer changed significantly from 3.0.8 to 3.18 for jz4780. The way clocks, regulators enabled. The way registers handled etc.. LCD and HDMI drivers changed completely.
HDMI WIP Resolution requires kernel recompile Check patches on https://groups.google.com/forum/#!forum/mips-creator-ci20-dev See [8]. Needs atomic mode setting and universal plane update for upstreaming
I2C Works drivers/i2c/busses/i2c-jz4780.c 4740 has HW issue so uses gpio i2c instead. 4770 had [9] but unused so removed (also gave false positives on i2cdetect). Works. Not 100% clear if gives spurious errors like 4770. Some i2x tx abrts etc. See [10]
IPU 4770 has driver integrated with fbdev driver, see [11]. Plans to move to DRM+KVM but may take time.
IR Driver upstream drivers/media/rc/gpio-ir-recv.c GPIO, so use upstream GPIO driver
MMC Works drivers/mmc/host/jz4740_mmc.c Various changes needed, see [12]. Should not rename driver. Check whether affected by [13]. See [14] Works. Consolidation work needed before upstream. jz4740 has diverged. DMA driver differences block.
NAND Works Works. Reworked driver See [15]
PWM drivers/pwm/pwm-jz4740.c 4770 uses same driver as 4740. Maybe applicable to 4780 too. See [16]. A modified jz4770 driver and an updated DT file are available here [17]. Note: SMP may be using the PWM clock - so perhaps it will need to be disabled?
Regulator Works Works. Based on i2c driver. Upstreamed. See [18]
SPI (SSI) None SPI GPIO should work, but a dedicated driver for the SSI hardware in drivers/spi/ would be better. SPI over GPIO has been added [19], but an SPI driver that uses the dedicated hardware would be better.
UART Works Quirks: see patches [20] [21] See serial patches in series [22]. Works
USB (EHCI) Works Works
USB (OHCI) Works Works
USB(DWC) Works Upstream driver supports only host mode as of 3.15 Works with Ingenic hack to disable over current warnings
VPU Driver aimed at 4770, see [23]. For samples see [24]. May be insecure (allows userland to do its own cache control and access TCSM banks). RemoteProc driver in progress, see [25].
Wifi WIP Check patches on https://groups.google.com/forum/#!forum/mips-creator-ci20-dev Works. Uses some hacks to keep regulators on to enable the chip. Uses upstreamed driver and mmc/dma.
BT WIP Almost works. Uses some hacks to keep regulators on to enable the chip. Scans ok however file transfer presents a few issues. It is possible that this is not entirely kernel's fault - it could be userland.

List of other possible issues when moving from 3.0.8 to 3.16+

Ethernet MAC Address

Due to the manufacturing process for the CI20, the ethernet's MAC address isn't burned into its EEPROM - it is instead burnt into EEPROM on the other side of the board. The move to 3.18 means the MAC address has to be set at boot time (otherwise a random MAC will be chosen).

This can be done using U-BOOT - add the following to your bootargs:

   dm9000.mac_addr=${ethaddr}

NOTE: Setting this bootarg for a kernel before 3.18 will cause a kernel panic.

Audio over HDMI

Audio over HDMI is not currently supported in kernel 3.18+, although it was supported in 3.0.8.

WiFi firmware

WiFi on the CI20 is provided by a BRCM4330 chip that requires closed source firmware. These files cannot be shipped as part of the kernel repository.

The required files can be found here or copied and renamed from the Debian NAND image

   ci20:/lib/firmware/iw8103/fw_bcm4330b2.bin -> /lib/firmware/brcm/brcmfmac4330-sdio.bin
   ci20:/lib/firmware/iw8103/nv_4330b2.txt -> /lib/firmware/brcm/brcmfmac4330-sdio.txt

Note: Without these files the wireless driver will fail when loading.

NAND

If you are using the default debian rootfs on NAND and just update the kernel then a change needs to be made to the bootargs.

The NAND drivers between 3.0.8 and 3.16 are different. And detect different partition structures - 3.0.8 detects rootfs on mtd1 whilst 3.18 detects rootfs on mtd3.

With this in mind, change U-BOOT's bootargs to:

setenv bootargs "console=ttyS4,115200 mem=256M@0x0  mem=768M@0x30000000 ubi.mtd=3 root=ubi0:root rootfstype=ubifs rw clock_ignore_unused"
                                                                                ^

Note: You might want to add another file in /boot instead of changing vmlinux.img so that you can still boot your CI20 if something is wrong with your kernel.

setenv bootcmd "mtdparts default; ubi part system; ubifsmount ubi:boot; ubifsload 0x88000000 uImage.3.18; bootm 0x88000000"
                                                                                             ^

Finally, save the environment:

saveenv

SGX

GPU drivers rely on userland binaries and kernel module sources. The work to move to a DRI based system is on-going at IMG. Until the drivers are updated, using the GPU (openGL etc) will not be possible.

For normal usage, Xorg and framebuffer drivers do work. The default xorg.conf is configured to load the PowerVR module. Keep a copy of that somewhere else and use this xorg.conf

Note: Rename to xorg.conf. Don't leave it named xorg.conf.fbdev.

Place in:

/etc/X11/xorg.conf