From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nikolaus Voss Subject: [PATCH v11 0/4] AT91: replace old i2c-at91.c TWI driver Date: Wed, 22 Aug 2012 08:59:20 +0200 Message-ID: Return-path: Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Cc: nicolas.ferre-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org, ben-linux-elnMNo+KYs3YtjvyW6yDsg@public.gmane.org, balbi-l0cyMroinI0@public.gmane.org, h.feurstein-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, rmallon-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, adrian.yanes-uOixanVlb7U@public.gmane.org, ludovic.desroches-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org, carsten.behling-0M7HhAU3Y85FsXB23wyQUg@public.gmane.org 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. Changes since v10: - fix for flags persistency suggested and tested by Carsten Behling - clk_lookup.dev_id entries for at91sam9x5 - calc_twi_clock fix for sam9261 by Ludovic Desroches Nikolaus Voss (4): drivers/i2c/busses/i2c-at91.c: remove old polling 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/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/at91sam9261_devices.c | 9 + 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/at91sam9x5.c | 3 + arch/arm/mach-at91/include/mach/at91_twi.h | 68 ---- drivers/i2c/busses/Kconfig | 11 +- drivers/i2c/busses/i2c-at91.c | 591 ++++++++++++++++++---------- 13 files changed, 418 insertions(+), 287 deletions(-) delete mode 100644 arch/arm/mach-at91/include/mach/at91_twi.h -- 1.7.9.5 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757502Ab2HVHg7 (ORCPT ); Wed, 22 Aug 2012 03:36:59 -0400 Received: from mo-p05-ob.rzone.de ([81.169.146.181]:33279 "EHLO mo-p05-ob.rzone.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756970Ab2HVHgv (ORCPT ); Wed, 22 Aug 2012 03:36:51 -0400 X-RZG-AUTH: :KXokZlStbvrPCC8w2n2KADUjx90tFpDbrwvi3rISAmCHBWiKTAoKIqY5gZEywA== X-RZG-CLASS-ID: mo05 Message-Id: From: Nikolaus Voss Date: Wed, 22 Aug 2012 08:59:20 +0200 Subject: [PATCH v11 0/4] AT91: replace old i2c-at91.c TWI driver 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, h.feurstein@gmail.com, rmallon@gmail.com, adrian.yanes@aalto.fi, ludovic.desroches@atmel.com, carsten.behling@garz-fricke.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. Changes since v10: - fix for flags persistency suggested and tested by Carsten Behling - clk_lookup.dev_id entries for at91sam9x5 - calc_twi_clock fix for sam9261 by Ludovic Desroches Nikolaus Voss (4): drivers/i2c/busses/i2c-at91.c: remove old polling 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/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/at91sam9261_devices.c | 9 + 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/at91sam9x5.c | 3 + arch/arm/mach-at91/include/mach/at91_twi.h | 68 ---- drivers/i2c/busses/Kconfig | 11 +- drivers/i2c/busses/i2c-at91.c | 591 ++++++++++++++++++---------- 13 files changed, 418 insertions(+), 287 deletions(-) delete mode 100644 arch/arm/mach-at91/include/mach/at91_twi.h -- 1.7.9.5