From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nikolaus Voss Subject: [PATCH V3 0/4] AT91: replace broken TWI driver i2c-at91.c Date: Tue, 8 Nov 2011 12:52:22 +0100 Message-ID: Return-path: Sender: linux-kernel-owner@vger.kernel.org To: linux-i2c@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Cc: ben-linux@fluff.org, khali@linux-fr.org, nicolas.ferre@atmel.com, rmallon@gmail.com, balbi@ti.com List-Id: linux-i2c@vger.kernel.org The old driver has two main deficencies: i) No repeated start (Sr) condiction is possible, this makes it unusable e.g. for most SMBus transfers. ii) I/O was done with polling/busy waiting what caused over-/underruns even at light system loads and clock speeds. The new driver overcomes these deficencies and in addition allows for more than one TWI interface. A remaining limitation is the fact, that only one repeated start is possible (two concatenated messages). This limitation is imposed by the hardware. However, this should not be a problem as all common i2c-client communication does not rely on more than one repeated start. V3: Integrated review comments from Ryan Mallon and Felipe Balbi V2: Fixed whitespace issue Nikolaus Voss (4): drivers/i2c/busses/i2c-at91.c: remove broken driver drivers/i2c/busses/i2c-at91.c: add new driver G45 TWI: remove open drain setting for twi function gpios Add lookup entries for twi_clk for devices with more than one TWI port arch/arm/mach-at91/at91sam9g45.c | 2 + arch/arm/mach-at91/at91sam9g45_devices.c | 6 - arch/arm/mach-at91/at91sam9rl.c | 2 + drivers/i2c/busses/Kconfig | 11 +- drivers/i2c/busses/i2c-at91.c | 453 +++++++++++++++++++----------- 5 files changed, 292 insertions(+), 182 deletions(-) -- 1.7.5.4