From mboxrd@z Thu Jan 1 00:00:00 1970 From: ludovic.desroches Subject: Re: [PATCH v11 4/4] G45 TWI: remove open drain setting for twi function gpios Date: Mon, 27 Aug 2012 12:24:38 +0200 Message-ID: <503B4AE6.4090107@atmel.com> References: <6acdbd0f06cb9902efc510346564e10b07fa0b91.1345618760.git.n.voss@weinmann.de> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1"; Format="flowed" Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <6acdbd0f06cb9902efc510346564e10b07fa0b91.1345618760.git.n.voss@weinmann.de> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Nikolaus Voss Cc: rmallon@gmail.com, nicolas.ferre@atmel.com, linux-kernel@vger.kernel.org, balbi@ti.com, h.feurstein@gmail.com, ludovic.desroches@atmel.com, linux-i2c@vger.kernel.org, ben-linux@fluff.org, adrian.yanes@aalto.fi, linux-arm-kernel@lists.infradead.org, carsten.behling@garz-fricke.com List-Id: linux-i2c@vger.kernel.org Hi Nikolaus, Le 11/08/2011 12:11 PM, Nikolaus Voss a =E9crit : > The G45 datasheets explicitly states that setting the open drain property > on peripheral function gpios is not allowed. (How about other A91 chips?) > Did you remove open drain because you had some issues or because you had = seen it into datasheet? I tried with and without open drain. The behavior was the same. Looking = to the G45 datasheet, I didn't see that the open drain property is not = allowed on peripheral function gpios: 'The Multi Drive can be selected whether the I/O line is controlled by the PIO controller or assigned to a peripheral function.' The datasheet should have been updated or there is another place where = it is mentioned that open drain property is not allowed in this case. Regards Ludovic > Signed-off-by: Nikolaus Voss > --- > arch/arm/mach-at91/at91sam9g45_devices.c | 6 ------ > 1 file changed, 6 deletions(-) > > diff --git a/arch/arm/mach-at91/at91sam9g45_devices.c b/arch/arm/mach-at9= 1/at91sam9g45_devices.c > index eec5eb6..2134663 100644 > --- a/arch/arm/mach-at91/at91sam9g45_devices.c > +++ b/arch/arm/mach-at91/at91sam9g45_devices.c > @@ -686,18 +686,12 @@ void __init at91_add_device_i2c(short i2c_id, struc= t i2c_board_info *devices, in > /* pins used for TWI interface */ > if (i2c_id =3D=3D 0) { > at91_set_A_periph(AT91_PIN_PA20, 0); /* TWD */ > - at91_set_multi_drive(AT91_PIN_PA20, 1); > - > at91_set_A_periph(AT91_PIN_PA21, 0); /* TWCK */ > - at91_set_multi_drive(AT91_PIN_PA21, 1); > > platform_device_register(&at91sam9g45_twi0_device); > } else { > at91_set_A_periph(AT91_PIN_PB10, 0); /* TWD */ > - at91_set_multi_drive(AT91_PIN_PB10, 1); > - > at91_set_A_periph(AT91_PIN_PB11, 0); /* TWCK */ > - at91_set_multi_drive(AT91_PIN_PB11, 1); > > platform_device_register(&at91sam9g45_twi1_device); > } > From mboxrd@z Thu Jan 1 00:00:00 1970 From: ludovic.desroches@atmel.com (ludovic.desroches) Date: Mon, 27 Aug 2012 12:24:38 +0200 Subject: [PATCH v11 4/4] G45 TWI: remove open drain setting for twi function gpios In-Reply-To: <6acdbd0f06cb9902efc510346564e10b07fa0b91.1345618760.git.n.voss@weinmann.de> References: <6acdbd0f06cb9902efc510346564e10b07fa0b91.1345618760.git.n.voss@weinmann.de> Message-ID: <503B4AE6.4090107@atmel.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Nikolaus, Le 11/08/2011 12:11 PM, Nikolaus Voss a ?crit : > The G45 datasheets explicitly states that setting the open drain property > on peripheral function gpios is not allowed. (How about other A91 chips?) > Did you remove open drain because you had some issues or because you had seen it into datasheet? I tried with and without open drain. The behavior was the same. Looking to the G45 datasheet, I didn't see that the open drain property is not allowed on peripheral function gpios: 'The Multi Drive can be selected whether the I/O line is controlled by the PIO controller or assigned to a peripheral function.' The datasheet should have been updated or there is another place where it is mentioned that open drain property is not allowed in this case. Regards Ludovic > Signed-off-by: Nikolaus Voss > --- > arch/arm/mach-at91/at91sam9g45_devices.c | 6 ------ > 1 file changed, 6 deletions(-) > > diff --git a/arch/arm/mach-at91/at91sam9g45_devices.c b/arch/arm/mach-at91/at91sam9g45_devices.c > index eec5eb6..2134663 100644 > --- a/arch/arm/mach-at91/at91sam9g45_devices.c > +++ b/arch/arm/mach-at91/at91sam9g45_devices.c > @@ -686,18 +686,12 @@ void __init at91_add_device_i2c(short i2c_id, struct i2c_board_info *devices, in > /* pins used for TWI interface */ > if (i2c_id == 0) { > at91_set_A_periph(AT91_PIN_PA20, 0); /* TWD */ > - at91_set_multi_drive(AT91_PIN_PA20, 1); > - > at91_set_A_periph(AT91_PIN_PA21, 0); /* TWCK */ > - at91_set_multi_drive(AT91_PIN_PA21, 1); > > platform_device_register(&at91sam9g45_twi0_device); > } else { > at91_set_A_periph(AT91_PIN_PB10, 0); /* TWD */ > - at91_set_multi_drive(AT91_PIN_PB10, 1); > - > at91_set_A_periph(AT91_PIN_PB11, 0); /* TWCK */ > - at91_set_multi_drive(AT91_PIN_PB11, 1); > > platform_device_register(&at91sam9g45_twi1_device); > } >