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authorDavid Brownell <david-b@pacbell.net>2007-09-25 07:17:48 -0700
committerHaavard Skinnemoen <hskinnemoen@atmel.com>2007-10-11 13:32:55 +0200
commit82c54f864fea26c4c44f27e2b4c4d9a811dde299 (patch)
tree00e945ae58c132c94e4cc00254221005d3757343 /arch/avr32/boards
parenta7ff43b808f077e7aae2772b2f1a06a39e6b0cf8 (diff)
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[AVR32] ngw100 i2c-gpio tweaks
Make the NGW100 bitbang i2c use open drain signaling. Also, speed it up, so it's closer to 100 kHz ... the code paths seem to be long enough that the udelay isn't dominating bit times. The peak bit rate I observed was around 125 kHz, but that's with large delays (usually before ACK/NAK) which hold the overall rate down to around 80 kHz (call it 100 usec/byte on average). Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Diffstat (limited to 'arch/avr32/boards')
-rw-r--r--arch/avr32/boards/atngw100/setup.c13
1 files changed, 9 insertions, 4 deletions
diff --git a/arch/avr32/boards/atngw100/setup.c b/arch/avr32/boards/atngw100/setup.c
index 6e180f4..52987c8 100644
--- a/arch/avr32/boards/atngw100/setup.c
+++ b/arch/avr32/boards/atngw100/setup.c
@@ -125,8 +125,11 @@ static struct platform_device ngw_gpio_leds = {
};
static struct i2c_gpio_platform_data i2c_gpio_data = {
- .sda_pin = GPIO_PIN_PA(6),
- .scl_pin = GPIO_PIN_PA(7),
+ .sda_pin = GPIO_PIN_PA(6),
+ .scl_pin = GPIO_PIN_PA(7),
+ .sda_is_open_drain = 1,
+ .scl_is_open_drain = 1,
+ .udelay = 2, /* close to 100 kHz */
};
static struct platform_device i2c_gpio_device = {
@@ -162,8 +165,10 @@ static int __init atngw100_init(void)
}
platform_device_register(&ngw_gpio_leds);
- at32_select_gpio(i2c_gpio_data.sda_pin, 0);
- at32_select_gpio(i2c_gpio_data.scl_pin, 0);
+ at32_select_gpio(i2c_gpio_data.sda_pin,
+ AT32_GPIOF_MULTIDRV | AT32_GPIOF_OUTPUT | AT32_GPIOF_HIGH);
+ at32_select_gpio(i2c_gpio_data.scl_pin,
+ AT32_GPIOF_MULTIDRV | AT32_GPIOF_OUTPUT | AT32_GPIOF_HIGH);
platform_device_register(&i2c_gpio_device);
return 0;