[PATCH v5 0/5] ARM: sunxi: Add Reduced Serial Bus support

Chen-Yu Tsai wens at csie.org
Thu Oct 1 04:57:46 PDT 2015

Hi everyone,

This is my fifth attempt at adding support for Allwinner's Reduced
Serial Bus (RSB), which is used to communicate with PMICs and other
peripherals on their newer SoCs, such as the A23/A33/A80.

RSB is a simplified two wire interface using push-pull outputs,
supporting multiple slaves, address and data parity checks, and
clock speeds up to 20 MHz. The bus only supports simple register
read/writes, with possible register sizes of 8/16/32 bits. Access
sizes not matching the slave device register sizes result in NACKs
or errors. 32 bit registers in devices have yet to be seen.

v4 and later adds a platform driver for the RSB controller under
drivers/soc/sunxi, which adds a custom driver type and bus type
for slave drivers to use. Custom regmap support is also merged
into the controller driver. Currently the driver only exports 2
symbols: sunxi_rsb_driver_register() & __devm_regmap_init_sunxi_rsb().

Changes since v4:

  - Add newlines to printk calls missing them.

  - Removed bus type checks (dev->bus != &sunxi_rsb_bus)

  - Use different lockdep class for each regmap init call, as in
    3cfe7a74d42b ("regmap: Use different lockdep class for each regmap
    init call")

  - Move enabling RSB controller from ippo-q8h-v5 dts to sun8i-q8-common

Patch 1 adds the DT bindings for Allwinner RSB controller.

Patch 2 adds the driver itself.

Patch 3 adds the RSB nodes for A23/A33 dtsi.

Patch 4 enables the RSB controller on A23/A33 Q8 format tablets.

Patch 5 enables the RSB controller on Sinlinx SinA33.

Still to come are axp20x driver support for the RSB based AXP223.
The complete series can be found at:


This is now sunxi specific, so if everything works out, it should
all go through Maxime's tree?


Chen-Yu Tsai (5):
  soc: sunxi: Add Allwinner Reduced Serial Bus (RSB) controller bindings
  soc: sunxi: Add driver for Allwinner Reduced Serial Bus
  ARM: dts: sun8i: Add Reduced Serial Bus controller device node to
    A23/A33 dtsi
  ARM: dts: sun8i: q8-common: Enable RSB controller for A23/A33 Q8
  ARM: dts: sun8i: sinlinx-sina33: Enable Reduced Serial Bus controller

 .../devicetree/bindings/soc/sunxi/rsb.txt          |  47 ++
 arch/arm/boot/dts/sun8i-a23-a33.dtsi               |  21 +
 arch/arm/boot/dts/sun8i-a33-sinlinx-sina33.dts     |   4 +
 arch/arm/boot/dts/sun8i-q8-common.dtsi             |   4 +
 drivers/soc/sunxi/Kconfig                          |  10 +
 drivers/soc/sunxi/Makefile                         |   1 +
 drivers/soc/sunxi/sunxi_rsb.c                      | 783 +++++++++++++++++++++
 include/linux/soc/sunxi/sunxi_rsb.h                | 105 +++
 8 files changed, 975 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/soc/sunxi/rsb.txt
 create mode 100644 drivers/soc/sunxi/sunxi_rsb.c
 create mode 100644 include/linux/soc/sunxi/sunxi_rsb.h


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