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| author | Boris BREZILLON <boris.brezillon@free-electrons.com> | 2014-06-11 11:17:30 +0200 |
|---|---|---|
| committer | Wolfram Sang <wsa@the-dreams.de> | 2014-06-12 00:24:06 +0200 |
| commit | 3e833490fae55633f6adc03a5e6172d47c01f3e4 (patch) | |
| tree | 3288418e64b59594729bdd049bff06120dfc6a64 /drivers/i2c/busses/Kconfig | |
| parent | bb336ba0aaa5bef253d60bdeb08537ddecc7f42f (diff) | |
| download | op-kernel-dev-3e833490fae55633f6adc03a5e6172d47c01f3e4.zip op-kernel-dev-3e833490fae55633f6adc03a5e6172d47c01f3e4.tar.gz | |
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 <boris.brezillon@free-electrons.com>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Diffstat (limited to 'drivers/i2c/busses/Kconfig')
| -rw-r--r-- | drivers/i2c/busses/Kconfig | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index 759ee30..9f7d585 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -774,6 +774,19 @@ config I2C_STU300 This driver can also be built as a module. If so, the module will be called i2c-stu300. +config I2C_SUN6I_P2WI + tristate "Allwinner sun6i internal P2WI controller" + depends on RESET_CONTROLLER + depends on MACH_SUN6I || COMPILE_TEST + help + If you say yes to this option, support will be included for the + P2WI (Push/Pull 2 Wire Interface) controller embedded in some sunxi + SOCs. + The P2WI looks like an SMBus controller (which supports only byte + accesses), except that it only supports one slave device. + This interface is used to connect to specific PMIC devices (like the + AXP221). + config I2C_TEGRA tristate "NVIDIA Tegra internal I2C controller" depends on ARCH_TEGRA |
