[PATCH 4/8] ARM: at91: do not configure at91sam9g10 twi pio as open-drain

ludovic.desroches at atmel.com ludovic.desroches at atmel.com
Fri Aug 31 19:21:20 EST 2012


From: Ludovic Desroches <ludovic.desroches at atmel.com>

As indicated in the datasheet, TWD and TWCK must not be programmed as
open-drain.

Signed-off-by: Ludovic Desroches <ludovic.desroches at atmel.com>
---
 arch/arm/mach-at91/at91sam9261_devices.c | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/arch/arm/mach-at91/at91sam9261_devices.c b/arch/arm/mach-at91/at91sam9261_devices.c
index c94495d..405f603 100644
--- a/arch/arm/mach-at91/at91sam9261_devices.c
+++ b/arch/arm/mach-at91/at91sam9261_devices.c
@@ -324,20 +324,22 @@ static struct platform_device at91sam9261_twi_device = {
 
 void __init at91_add_device_i2c(struct i2c_board_info *devices, int nr_devices)
 {
-	/* IP version is not the same on 9261 and g10 */
+	/*
+	 * IP version is not the same on 9261 and g10 and only 9261 one
+	 * requires to configure PIO as open-drain.
+	 */
 	if (cpu_is_at91sam9g10()) {
 		at91sam9261_twi_device.name = "at91sam9g10_i2c";
+		at91_set_A_periph(AT91_PIN_PA7, 0);		/* TWD */
+		at91_set_A_periph(AT91_PIN_PA8, 0);		/* TWCK */
 	} else {
 		at91sam9261_twi_device.name = "at91sam9261_i2c";
+		at91_set_A_periph(AT91_PIN_PA7, 0);		/* TWD */
+		at91_set_multi_drive(AT91_PIN_PA7, 1);
+		at91_set_A_periph(AT91_PIN_PA8, 0);		/* TWCK */
+		at91_set_multi_drive(AT91_PIN_PA8, 1);
 	}
 
-	/* pins used for TWI interface */
-	at91_set_A_periph(AT91_PIN_PA7, 0);		/* TWD */
-	at91_set_multi_drive(AT91_PIN_PA7, 1);
-
-	at91_set_A_periph(AT91_PIN_PA8, 0);		/* TWCK */
-	at91_set_multi_drive(AT91_PIN_PA8, 1);
-
 	i2c_register_board_info(0, devices, nr_devices);
 	platform_device_register(&at91sam9261_twi_device);
 }
-- 
1.7.11.3



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