From 3e833490fae55633f6adc03a5e6172d47c01f3e4 Mon Sep 17 00:00:00 2001 From: Boris BREZILLON Date: Wed, 11 Jun 2014 11:17:30 +0200 Subject: i2c: sunxi: add P2WI (Push/Pull 2 Wire Interface) controller support 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 Signed-off-by: Boris BREZILLON Acked-by: Maxime Ripard Acked-by: Arnd Bergmann Signed-off-by: Wolfram Sang --- drivers/i2c/busses/Makefile | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/i2c/busses/Makefile') diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile index 8ac83374cf7e..dd9a7f8e873f 100644 --- a/drivers/i2c/busses/Makefile +++ b/drivers/i2c/busses/Makefile @@ -75,6 +75,7 @@ obj-$(CONFIG_I2C_SIMTEC) += i2c-simtec.o obj-$(CONFIG_I2C_SIRF) += i2c-sirf.o obj-$(CONFIG_I2C_ST) += i2c-st.o obj-$(CONFIG_I2C_STU300) += i2c-stu300.o +obj-$(CONFIG_I2C_SUN6I_P2WI) += i2c-sun6i-p2wi.o obj-$(CONFIG_I2C_TEGRA) += i2c-tegra.o obj-$(CONFIG_I2C_VERSATILE) += i2c-versatile.o obj-$(CONFIG_I2C_WMT) += i2c-wmt.o -- cgit v1.2.3