Hello, This series adds support for the P2WI block used by some Allwinner boards to interface with the AXP221 PMIC. The P2WI controller looks like an SMBus controller which only supports byte data transfers. But, it differs from standard SMBus protocol on several aspects: - it supports only one slave device, and thus drop the address field - it adds a parity bit every 8bits of data - only one read access is required to read a byte (instead of a write followed by a read access in standard SMBus protocol) - there's no Ack bit after each byte transfer This means this bus cannot be used to interface with standard SMBus devices (the only known device to support this interface is the AXP221 PMIC). However the P2WI protocol is close enough to SMBus to be integrated in the I2C subsystem (see this thread [1] for detailed reasons that led to integrating this driver in the I2C subsystem). [1] http://www.spinics.net/lists/linux-i2c/msg15066.html Best Regards, Boris Changes sinve v6: - declare as "GPL v2" instead of "GPL" - add Arnd's ack - add COMPILE_TEST support Changes since v5: - add Maxime's ack - rework commit message to mention the discussion that led to integrating this driver in the I2C subsystem - add missing dependency on RESET_CONTROLLER - clean up header inclusions - fix coding style issues Changes since v4: - add P2WI protocol description in driver header comment - remove unneeded i2c address check - remove unneeded irq field from p2wi struct Changes since v3: - update the DT bindings doc - fix a comment that was no longer true Changes since v2: - drop the initialization (switch from I2C to P2WI mode) part - print devm_ioremap_resource err code Boris BREZILLON (2): i2c: sunxi: add P2WI DT bindings documentation i2c: sunxi: add P2WI (Push/Pull 2 Wire Interface) controller support .../devicetree/bindings/i2c/i2c-sunxi-p2wi.txt | 41 +++ drivers/i2c/busses/Kconfig | 13 + drivers/i2c/busses/Makefile | 1 + drivers/i2c/busses/i2c-sun6i-p2wi.c | 345 +++++++++++++++++++++ 4 files changed, 400 insertions(+) create mode 100644 Documentation/devicetree/bindings/i2c/i2c-sunxi-p2wi.txt create mode 100644 drivers/i2c/busses/i2c-sun6i-p2wi.c -- 1.8.3.2 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
