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en:c2_hardware_irq [2016/04/26 11:23] charles.park [Hardware GPIO-IRQ] |
en:c2_hardware_irq [2017/03/08 08:00] (current) odroid [Hardware GPIO-IRQ] |
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| **ODROID-C2** supports the GPIO interrupt of Edge trigger.\\ | **ODROID-C2** supports the GPIO interrupt of Edge trigger.\\ | ||
| The maximum number of interrupt is limited to 8 when you use the falling(Low) or rising(High) edge trigger.\\ | The maximum number of interrupt is limited to 8 when you use the falling(Low) or rising(High) edge trigger.\\ | ||
| - | If you use the Both (rising and falling together) edge triggers, the maximum number is only 4. | + | If you use the Both (rising and falling together) edge triggers, the maximum number is only 4. \\ |
| - | You must use the **Linux 3.14.29-56 Apr** or higher to use the GPIO interrupt in the user-land. | + | Please note that SD card driver is using 2 interrupts to implement the card detection (insertion/remove) by default.\\ |
| + | So __**we can use only GPIO 6 IRQs**__. \\ | ||
| + | If you use an eMMC without SD card, you can access full 8 GPIO IRQs once you [[http://forum.odroid.com/viewtopic.php?f=136&t=26055&p=182162#p182037|disable the SD functionality]]. | ||
| + | |||
| + | You must use the **Linux Kernel 3.14.29-56 Apr** or higher to use the GPIO interrupt in the user-land. | ||
| ===== Usage ===== | ===== Usage ===== | ||
| To use the GPIO Interrupt in the User space, you must export the GPIO and add the Trigger option in Edge parameter.\\ | To use the GPIO Interrupt in the User space, you must export the GPIO and add the Trigger option in Edge parameter.\\ | ||
| - | GPIO SYSFS node is accessible via **/sys/class/aml_gpio/**. The access method is exactly same as /sys/class/gpio.\\ | + | GPIO SYSFS node is accessible via **/sys/class/gpio/**.\\ |
| === GPIO Export === | === GPIO Export === | ||
| - | echo [GPIO Number(Refer **[[en:c1_hardware|Expansion Connectors]]** )] > /sys/class/aml_gpio/export | + | echo [GPIO Number(Refer **[[en:c2_hardware#expansion_connectors]]** )] > /sys/class/gpio/export |
| - | e.g) GPIOY.BIT3 Export (Pin Number 7) | + | e.g) GPIOX.BIT21 Export (Pin Number 7) |
| <code> | <code> | ||
| - | echo 83 > /sys/class/aml_gpio/export | + | echo 249 > /sys/class/gpio/export |
| </code> | </code> | ||
| Line 33: | Line 37: | ||
| == Run == | == Run == | ||
| + | |||
| + | "Usage: aml_gpio_irq [GPIO Number]" | ||
| <code> | <code> | ||
| - | sudo aml_gpio_irq_test [GPIO Number] | + | sudo aml_gpio_irq_test 249 |
| </code> | </code> | ||
| Line 55: | Line 61: | ||
| //[*]-------------------------------------------------------------------------[*] | //[*]-------------------------------------------------------------------------[*] | ||
| - | #define SYSFS_GPIO_DIR "/sys/class/aml_gpio" | + | #define SYSFS_GPIO_DIR "/sys/class/gpio" |
| #define POLL_TIMEOUT (3 * 1000) /* 3 seconds */ | #define POLL_TIMEOUT (3 * 1000) /* 3 seconds */ | ||
| #define MAX_BUF 64 | #define MAX_BUF 64 | ||
| Line 288: | Line 294: | ||
| + | |||
| + | ===== Kernel driver GPIO IRQ Example code by crashoverride ===== | ||
| + | |||
| + | [[http://forum.odroid.com/viewtopic.php?f=112&t=18559|HC-SR04 kernel driver]] | ||
