From fac368a040484293006bb488e67972aafcf88ec7 Mon Sep 17 00:00:00 2001 From: Nikolaus Voss Date: Tue, 8 Nov 2011 11:49:46 +0100 Subject: i2c: at91: add new driver This driver has the following properties compared to the old driver: 1. Support for multiple interfaces. 2. Interrupt driven I/O as opposed to polling/busy waiting. 3. Support for _one_ repeated start (Sr) condition, which is enough for most real-world applications including all SMBus transfer types. (The hardware does not support issuing arbitrary Sr conditions on the bus.) testing: SoC: at91sam9g45 - BQ20Z80 battery SMBus client. - on a 2.6.38 kernel with several i2c clients (temp-sensor, audio-codec, touchscreen-controller, w1-bridge, io-expanders) Signed-off-by: Nikolaus Voss Reviewed-by: Felipe Balbi Tested-by: Hubert Feurstein Tested-by: Ludovic Desroches Reviewed-by: Nicolas Ferre [wsa: squashed with the following patches from Ludovic to have some flaws fixed: i2c: at91: use managed resources i2c: at91: add warning about transmission issues for some devices i2c: at91: use an id table for SoC dependent parameters ] Signed-off-by: Ludovic Desroches Signed-off-by: Wolfram Sang --- arch/arm/mach-at91/at91sam9261_devices.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) (limited to 'arch/arm/mach-at91/at91sam9261_devices.c') diff --git a/arch/arm/mach-at91/at91sam9261_devices.c b/arch/arm/mach-at91/at91sam9261_devices.c index bc2590d712d0..29188ef7422b 100644 --- a/arch/arm/mach-at91/at91sam9261_devices.c +++ b/arch/arm/mach-at91/at91sam9261_devices.c @@ -317,7 +317,6 @@ static struct resource twi_resources[] = { }; static struct platform_device at91sam9261_twi_device = { - .name = "at91_i2c", .id = -1, .resource = twi_resources, .num_resources = ARRAY_SIZE(twi_resources), @@ -325,6 +324,13 @@ 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 */ + if (cpu_is_at91sam9g10()) { + at91sam9261_twi_device.name = "i2c-at91sam9g10"; + } else { + at91sam9261_twi_device.name = "i2c-at91sam9261"; + } + /* pins used for TWI interface */ at91_set_A_periph(AT91_PIN_PA7, 0); /* TWD */ at91_set_multi_drive(AT91_PIN_PA7, 1); -- cgit v1.2.1 From 94e734655fbe294c50d304547cae033e87ec229e Mon Sep 17 00:00:00 2001 From: Ludovic Desroches Date: Wed, 12 Sep 2012 08:42:13 +0200 Subject: ARM: at91: do not configure at91sam9g10 twi pio as open-drain As indicated in the datasheet, TWD and TWCK must not be programmed as open-drain. Signed-off-by: Ludovic Desroches Acked-by: Nikolaus Voss Acked-by: Nicolas Ferre Signed-off-by: Wolfram Sang --- arch/arm/mach-at91/at91sam9261_devices.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'arch/arm/mach-at91/at91sam9261_devices.c') diff --git a/arch/arm/mach-at91/at91sam9261_devices.c b/arch/arm/mach-at91/at91sam9261_devices.c index 29188ef7422b..50d317940f5a 100644 --- a/arch/arm/mach-at91/at91sam9261_devices.c +++ b/arch/arm/mach-at91/at91sam9261_devices.c @@ -327,16 +327,16 @@ void __init at91_add_device_i2c(struct i2c_board_info *devices, int nr_devices) /* IP version is not the same on 9261 and g10 */ if (cpu_is_at91sam9g10()) { at91sam9261_twi_device.name = "i2c-at91sam9g10"; + /* I2C PIO must not be configured as open-drain on this chip */ } else { at91sam9261_twi_device.name = "i2c-at91sam9261"; + at91_set_multi_drive(AT91_PIN_PA7, 1); + 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); -- cgit v1.2.1