olerem / icc

inter chip communication

icc

inter chip communication

Possible client drivers:

• char (generic, do what you want)
• gpio extender
• rtc
• watchdog
• CAN
• rfkill

Notes:

• determenistic (to avoid real-time word).
• async. Sync communication on linux is expensive. (async need timeout to responde. Async need timout to responde as well, why should we wait any way?)
• agregation. most communications use tiny packets. tiny packets are very expensive.
• queue. aggregation is possible only with a queue.

Information collection for different Interchip and Intra Chip communication

TODO: 3946R, RK512, Modbus, IEC870, MEWTOCOL, AK, MPI, LSV2, Interbus, DeviceNet, MSV2:

Examples of Interchip Chip Communication:

• MCU to CPU bridge - Arduino Yún

• EC to CPU on x86 platforms

• ath9k-htc and other atheros Host To Chip bridges (p2p multip port)

• Nokia n900, linux/driver/hsi (p2p multiport)

• I2CSec http://www.sciencedirect.com/science/article/pii/S1383762110001633

• IC-USB https://en.wikipedia.org/wiki/InterChip_USB

• TI HDQ? http://www.ti.com/lit/an/slua408a/slua408a.pdf

• GSM.07.10 (gsmmux) linux/drivers/tty/n_gsm.c

• 3964R/3964 (Siemens?) linux/drivers/tty/n_r3964.c

• RK512 https://support.industry.siemens.com/cs/document/12932189/differences-between-protocols-3964(r)-and-rk-512?dti=0&lc=en-WW

• or 3964 + RK512? --- (- high overhead for simple p2p communication)

• LininoIO http://www.linino.org/wordpress/wp-content/uploads/2015/02/Fosdem_LininoIO.pdf

• mcuIO https://github.com/linino/kernel_3.3.8/tree/master/drivers/mcuio https://github.com/ciminaghi/bathos-mcuio

• WeIO USB + ttyACM + UPER https://github.com/8devices/UPER/wiki/UPER-function-list

• Texas Instruments Shared Transport driver for UART: drivers/misc/ti-st/st_core.c

• CPU to Application CPU Interface: https://www.kernel.org/doc/Documentation/networking/caif/Linux-CAIF.txt http://lxr.free-electrons.com/source/drivers/net/caif/caif_serial.c#L393 https://lwn.net/Articles/371017/

• ChromeOS EC multi-function device

  • https://chromium.googlesource.com/chromiumos/platform/ec/
  • https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/mfd/cros_ec.c

Intra Chip Communication

• Different variants of Virtualisation

---

• Name, HIF/PHY, Transport
• ath9k-htc, USB, OSI2(HTC) + OSI3(WMI)
• ath10k, PCIe, HTC
• ath6kl, SDIO, HTC
• n900, OMAP HSI, ???
• n_gsm.c TTY gsmmux
• n_3964 TTY OSI2 (3964r) + OSI3(RK512)

What is the difference between plain master slave communication and ICC? Abstraction level? Plaint Master-Slave: Slave_HW->Master_Bus->Bus_Driver->Slave_Driver ICC: Diff_functionalities->Slave_HW->Master_Bus->Bus_Driver->Multiple_Func_drivers