What's new is expected in v4.8-rc1 core for Intel Edison. Digest
About a year and a half has passed since my previous publication , dedicated to the support of Intel Atom Z34xx, and simply speaking Intel Edison, the vanilla Linux kernel. Here I will review the innovations that are waiting for their turn in the kernel version v4.8-rc1.
I complained for a long time about the absence of the Power Management Unit (PwrMU) driver for the platform, until I sat down and cleaned the known code to the state that allowed it to be included in the vanilla kernel. Thus, the devices of the south bridge, and these are almost all devices that are used for the periphery and IoT, do not consume excess energy. The presence of the driver allowed us to continue working on the rest of the platform.
The most important drivers on any embedded platform are GPIO and pinctrl. Without them, most devices on the board will work incorrectly or not at all. As it turned out relatively recently, the driver declared earlier in the vanilla kernels GPIO was in principle inoperable, and the pinctrl was completely absent. The need for these drivers is caused by the use of some contact pad (s) in different modes for controllers of other devices and buses.
Finally, users of devices connected to controllers of serial buses, namely SPI and I2C, will be delighted. The expected new version will include support for these controllers for the Intel Atom Z34xx, in addition, GPIO extenders (PCAL9555a) installed on the Edison-Arduino board will be initialized by default, and the SPI5 will receive its special device /dev/spidev5.1 (chip select signal 0 wound up on the ADC, and the choice of chip 1 is the user-connected device).
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In addition to the above, a step is made to meet WiFi. And although at the moment some of the changes in my local tree, thanks to them, the SDIO card, bcm43340, is recognized by the driver, although it behaves very unstable, and does not see the network, although the wlan0 interface is registered.
To continue the list of goals that I would like to achieve in the vanilla core, the following points (minimum plan):
Work as for one person during off-hours is actually a bit too much, people willing to help are accepted with joy!
The experimental source tree is here: github.com/andy-shev/linux/commits/eds
I complained for a long time about the absence of the Power Management Unit (PwrMU) driver for the platform, until I sat down and cleaned the known code to the state that allowed it to be included in the vanilla kernel. Thus, the devices of the south bridge, and these are almost all devices that are used for the periphery and IoT, do not consume excess energy. The presence of the driver allowed us to continue working on the rest of the platform.
GPIO and pinctrl
The most important drivers on any embedded platform are GPIO and pinctrl. Without them, most devices on the board will work incorrectly or not at all. As it turned out relatively recently, the driver declared earlier in the vanilla kernels GPIO was in principle inoperable, and the pinctrl was completely absent. The need for these drivers is caused by the use of some contact pad (s) in different modes for controllers of other devices and buses.
Serial bus drivers
Finally, users of devices connected to controllers of serial buses, namely SPI and I2C, will be delighted. The expected new version will include support for these controllers for the Intel Atom Z34xx, in addition, GPIO extenders (PCAL9555a) installed on the Edison-Arduino board will be initialized by default, and the SPI5 will receive its special device /dev/spidev5.1 (chip select signal 0 wound up on the ADC, and the choice of chip 1 is the user-connected device).
')
Closer to the air
In addition to the above, a step is made to meet WiFi. And although at the moment some of the changes in my local tree, thanks to them, the SDIO card, bcm43340, is recognized by the driver, although it behaves very unstable, and does not see the network, although the wlan0 interface is registered.
Work is in full swing
To continue the list of goals that I would like to achieve in the vanilla core, the following points (minimum plan):
- steady work pwm
- get as close to WiFi as possible
- micro-SD slot operation
- CPU C-states support in intel_idle driver
Join the process
Work as for one person during off-hours is actually a bit too much, people willing to help are accepted with joy!
The experimental source tree is here: github.com/andy-shev/linux/commits/eds
Source: https://habr.com/ru/post/305880/
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