[PATCH v11 4/4] G45 TWI: remove open drain setting for twi function gpios

2012-08-29 Thread Nikolaus Voss 
The G45 datasheets explicitly states that setting the open drain property
on peripheral function gpios is not allowed. (How about other A91 chips?)

Signed-off-by: Nikolaus Voss n.v...@weinmann.de
---
 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);
}
-- 
1.7.9.5

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RE: [PATCH v11 4/4] G45 TWI: remove open drain setting for twi function gpios

2012-08-27 Thread Voss, Nikolaus 
Hi Ludovic,

ludovic.desroches wrote on Monday, August 27, 2012 12:25 PM:
 Le 11/08/2011 12:11 PM, Nikolaus Voss a écrit :
 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.

well, it didn't work on my G45. I found the following note in the
TWI chapter 31.6.1 of the G45 datasheet:
The user must not program TWD and TWCK as open-drain.
It is already done by the hardware.

After removing the open-drain setting, it worked.

Regards,
Nikolaus


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[PATCH v11 4/4] G45 TWI: remove open drain setting for twi function gpios

2012-08-22 Thread Nikolaus Voss 
The G45 datasheets explicitly states that setting the open drain property
on peripheral function gpios is not allowed. (How about other A91 chips?)

Signed-off-by: Nikolaus Voss n.v...@weinmann.de
---
 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);
}
-- 
1.7.9.5

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