From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757124Ab2CSPqR (ORCPT ); Mon, 19 Mar 2012 11:46:17 -0400 Received: from mo-p05-ob.rzone.de ([81.169.146.180]:25389 "EHLO mo-p05-ob.rzone.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964907Ab2CSPqP (ORCPT ); Mon, 19 Mar 2012 11:46:15 -0400 X-RZG-AUTH: :KXokZlStbvrPCC8w2n2KADUjx90tFpDbrwvi3rISAmCHBWiKTAoKIqY5gZEywA== X-RZG-CLASS-ID: mo05 Message-Id: From: Nikolaus Voss Date: Mon, 19 Mar 2012 16:07:10 +0100 Subject: [PATCH v9 0/4] AT91: replace broken TWI driver i2c-at91.c To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-i2c@vger.kernel.org Cc: nicolas.ferre@atmel.com, ben-linux@fluff.org, balbi@ti.com, , Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@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. Signed-off-by: Nikolaus Voss Reviewed-by: Felipe Balbi Tested-by: Hubert Feurstein v9: i) merge i2c-at91.c patches to single patch ii) rewrite cwgr reg after timeout to reenable the right twi clock v8: i) remove local include ii) remove cpu_is_rm9200() and put twi hw bug info in platform_device iii) use readl/writel_relaxed instead of __raw_readl/writel v7: i) fix bug if internal address > 1 byte ii) send stop when len == 1 (both reported by Carsten Behling) v6: support for I2C_SMBUS_BLOCK_DATA transfers. Better use of clk_(un)prepare(). More sensible transfer timeout. v5: Another round of review comments from Ryan Mallon, Felipe Balbi and Russell King: convert twi clk to use .dev_id, cleanups v4: Integrated more review comments from Ryan Mallon and Felipe Balbi: Moved register include file to local include, code cleanups 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 Replace clk_lookup.con_id with clk_lookup.dev_id entries for twi clk drivers/i2c/busses/i2c-at91.c: add new driver G45 TWI: remove open drain setting for twi function gpios arch/arm/mach-at91/at91cap9.c | 1 + arch/arm/mach-at91/at91rm9200.c | 1 + arch/arm/mach-at91/at91rm9200_devices.c | 9 + arch/arm/mach-at91/at91sam9260.c | 1 + arch/arm/mach-at91/at91sam9261.c | 1 + arch/arm/mach-at91/at91sam9263.c | 1 + arch/arm/mach-at91/at91sam9g45.c | 2 + arch/arm/mach-at91/at91sam9g45_devices.c | 6 - arch/arm/mach-at91/at91sam9rl.c | 2 + arch/arm/mach-at91/include/mach/at91_twi.h | 68 ---- drivers/i2c/busses/Kconfig | 11 +- drivers/i2c/busses/i2c-at91.c | 561 +++++++++++++++++----------- 12 files changed, 373 insertions(+), 291 deletions(-) delete mode 100644 arch/arm/mach-at91/include/mach/at91_twi.h -- 1.7.5.4