RE: [PATCH 4/8] ARM: at91: do not configure at91sam9g10 twi pio as open-drain
From: Voss, Nikolaus <hidden>
Date: 2012-09-03 05:57:09
Also in:
linux-arm-kernel, linux-i2c
Possibly related (same subject, not in this thread)
- 2012-09-06 · Re: [PATCH 4/8] ARM: at91: do not configure at91sam9g10 twi pio as open-drain · Warner Losh <hidden>
- 2012-08-31 · [PATCH 4/8] ARM: at91: do not configure at91sam9g10 twi pio as open-drain · <hidden>
- 2012-08-31 · [PATCH 4/8] ARM: at91: do not configure at91sam9g10 twi pio as open-drain · <hidden>
ludovic.desroches-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org wrote on Friday, August 31, 2012 11:21 AM
From: Ludovic Desroches <redacted> As indicated in the datasheet, TWD and TWCK must not be programmed as open-drain. Signed-off-by: Ludovic Desroches <redacted>
Acked-by: Nikolaus Voss <redacted>
quoted hunk
--- 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_deviceat91sam9261_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