On 01/31/2014 04:46 AM, Valentin Longchamp wrote:
From: Rainer Boschung rainer.boschung@keymile.com
This patch adds support for using some GPIOs that are connected to the I2C bus to force the bus lines state and perform some bus deblocking sequences.
The KM common deblocking algorithm from board/keymile/common/common.c is used. The GPIO lines used for deblocking the I2C bus are some external GPIOs provided by the QRIO CPLD:
- SCL = GPIOA_20
- SDA = GPIOA_21
The QRIO GPIOs act in an open-drain-like manner, for 0 the line is driven low and for 1 the GPIO is set as input and the line gets pulled-up.
Signed-off-by: Rainer Boschung rainer.boschung@keymile.com Signed-off-by: Valentin Longchamp valentin.longchamp@keymile.com
Changes in v3:
- rewrite the commit message and and the comments for more clarity
- fix the GPIO numbers that where not correct
Changes in v2: None
board/keymile/kmp204x/kmp204x.c | 53 ++++++++++++++++++++++++++++++++++--- include/configs/km/kmp204x-common.h | 10 +++++++ 2 files changed, 60 insertions(+), 3 deletions(-)
diff --git a/board/keymile/kmp204x/kmp204x.c b/board/keymile/kmp204x/kmp204x.c index bbb2453..726d26e 100644 --- a/board/keymile/kmp204x/kmp204x.c +++ b/board/keymile/kmp204x/kmp204x.c @@ -33,12 +33,51 @@ int checkboard(void) return 0; }
-/* TODO: implement the I2C deblocking function */ -int i2c_make_abort(void) +/* I2C deblocking uses the algorithm defined in board/keymile/common/common.c
- 2 dedicated QRIO GPIOs externally pull the SCL and SDA lines
- For I2C only the low state is activly driven and high state is pulled-up
- by a resistor. Therefore the deblock GPIOs are used
- -> as an active output to drive a low state
- -> as an open-drain input to have a pulled-up high state
- */
+/* QRIO GPIOs used for deblocking */ +#define DEBLOCK_PORT1 GPIO_A +#define DEBLOCK_SCL1 20 +#define DEBLOCK_SDA1 21
You changed these macros but didn't change those below. This causes compiling errors. Please fix it and compile before sending v4.
+/* By default deblock GPIOs are floating */ +static void i2c_deblock_gpio_cfg(void) +{
- /* set I2C bus 1 deblocking GPIOs input, but 0 value for open drain */
- qrio_gpio_direction_input(DBLK_PORT1, DBLK_SCL1);
- qrio_gpio_direction_input(DBLK_PORT1, DBLK_SDA1);
- qrio_set_gpio(DBLK_PORT1, DBLK_SCL1, 0);
- qrio_set_gpio(DBLK_PORT1, DBLK_SDA1, 0);
+}
York