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This article mainly analyzes the relevant knowledge of the specific use of Linux kernel gpio for everyone, the content is detailed and easy to understand, the operation details are reasonable, and has a certain reference value. If you are interested, you might as well follow the editor and learn more about "what is the specific use of Linux kernel gpio".

Gpio is the simplest and most commonly used driver in the Linux kernel, and applications can use gpio through the corresponding interface.

The concrete usage of Linux Kernel gpio

Use gpio

To use the gpio interface, you need to include # include. To use the delay function mdelay in the driver, you need to include the # include file. The Documentation/gpio.txt file is described in detail.

Determine whether an IO is legal:

Int gpio_is_valid (int number); sets the direction of the GPIO and sets the level at the same time if it is the output:

/ * set as input or output, returning 0 or negative errno * / int gpio_direction_input (unsigned gpio); int gpio_direction_output (unsigned gpio, int value); get the level of the input pin:

/ * GPIO INPUT: return zero or nonzero * / int gpio_get_value (unsigned gpio); / * GPIO OUTPUT * / void gpio_set_value (unsigned gpio, int value); int gpio_cansleep (unsigned gpio); / * GPIO INPUT: return zero or nonzero, might sleep * / int gpio_get_value_cansleep (unsigned gpio); / * GPIO OUTPUT, might sleep * / void gpio_set_value_cansleep (unsigned gpio, int value); get a GPIO and declare the tag:

/ * request GPIO, returning 0 or negative errno. * non-null labels may be useful for diagnostics. * / int gpio_request (unsigned gpio, const char * label); / * release previously-claimed GPIO * / void gpio_free (unsigned gpio); / * request GPIO, returning 0 or negative errno.`` * non-null labels may be useful ``for``diagnostics.`` * / ``int gpio_request (unsigned gpio, const char * label); ``/ * release previously-claimed GPIO * / ``void gpio_free (unsigned gpio); map GPIO to IRQ interrupt:

If (! sw- > both_edges) {if (gpio_get_value (sw- > gpio)) {set_irq_type (gpio_to_irq (sw- > gpio), IRQ_TYPE_EDGE_FALLING);} else {set_irq_type (gpio_to_irq (sw- > gpio), IRQ_TYPE_EDGE_RISING);}} set IRQ interrupt type for GPIO:

If (! sw- > both_edges) {if (gpio_get_value (sw- > gpio)) {set_irq_type (gpio_to_irq (sw- > gpio), IRQ_TYPE_EDGE_FALLING);} else {set_irq_type (gpio_to_irq (sw- > gpio), IRQ_TYPE_EDGE_RISING) }} about "what is the specific use of Linux kernel gpio" here, more related content can be searched for previous articles, hope to help you answer questions, please support the website!

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