Raspberry Linux GPIO interrupt
2021-09-12 本文已影响0人
star_walker
1. Learn before read
https://blog.csdn.net/droidphone/article/details/7445825
http://blog.chinaunix.net/uid-17188120-id-4187440.html
2. The main functions need to use
// include/linux/gpio.h
static inline int gpio_to_irq(unsigned int gpio)
// include/linux/interrupt.h
/*
* These correspond to the IORESOURCE_IRQ_* defines in
* linux/ioport.h to select the interrupt line behaviour. When
* requesting an interrupt without specifying a IRQF_TRIGGER, the
* setting should be assumed to be "as already configured", which
* may be as per machine or firmware initialisation.
*/
#define IRQF_TRIGGER_NONE 0x00000000
#define IRQF_TRIGGER_RISING 0x00000001
#define IRQF_TRIGGER_FALLING 0x00000002
#define IRQF_TRIGGER_HIGH 0x00000004
#define IRQF_TRIGGER_LOW 0x00000008
#define IRQF_TRIGGER_MASK (IRQF_TRIGGER_HIGH | IRQF_TRIGGER_LOW | \
IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING)
#define IRQF_TRIGGER_PROBE 0x00000010
static inline int __must_check request_irq(unsigned int irq, irq_handler_t handler, unsigned long flags, const char *name, void *dev)
extern const void *free_irq(unsigned int, void *);
extern void disable_irq(unsigned int irq);
extern void enable_irq(unsigned int irq);
3. Sample code to show it works
#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/cdev.h>
#include <linux/device.h>
#include <linux/input.h>
#include <linux/platform_device.h>
#include <linux/gpio.h>
#include <linux/sysfs.h>
#include <linux/interrupt.h>
MODULE_LICENSE("GPL");
#define LIGHTSENSORGPIO 23
int lightsensor_irq;
static irqreturn_t lightsensor_irq_handler(int irq, void *dev_id)
{
printk(KERN_INFO "lightsensor irq, got it\n");
return IRQ_HANDLED;
}
static int __init hello_world_init(void)
{
int ret;
printk(KERN_ERR "hello world!!!\n");
ret = gpio_request(LIGHTSENSORGPIO, "LightSensorIrq");
if (ret < 0) {
printk(KERN_ERR "hello: request gpio failed\n");
goto error;
}
ret = gpio_direction_input(LIGHTSENSORGPIO);
if (ret < 0) {
printk(KERN_ERR "hello: set gpio direction failed\n");
goto error;
}
lightsensor_irq = gpio_to_irq(LIGHTSENSORGPIO);
ret = request_irq(lightsensor_irq, lightsensor_irq_handler, IRQF_TRIGGER_RISING, "LightSensorIrq", NULL);
if (ret < 0) {
printk(KERN_ERR "hello: request irq failed\n");
goto error;
}
return 0;
error:
gpio_free(LIGHTSENSORGPIO);
return -1;
}
static void __exit hello_world_exit(void)
{
free_irq(lightsensor_irq, NULL);
gpio_free(LIGHTSENSORGPIO);
printk(KERN_ALERT "hell_exit\r\n");
}
module_init(hello_world_init);
module_exit(hello_world_exit);
4. Result after execute
root@l:/home/l# [ 353.343011] lightsensor irq, got it
[ 353.712772] lightsensor irq, got it
[ 353.953947] lightsensor irq, got it
[ 354.274983] lightsensor irq, got it
[ 354.497476] lightsensor irq, got it
[ 355.094600] lightsensor irq, got it
root@l:/home/l#
root@l:/home/l#
root@l:/home/l# cat /proc/interrupts
CPU0 CPU1 CPU2 CPU3
9: 0 0 0 0 GICv2 25 Level vgic
12: 26787 33227 33012 27719 GICv2 30 Level arch_timer
13: 0 0 0 0 GICv2 27 Level kvm guest vtimer
19: 0 0 0 0 GICv2 107 Level fe004000.txp
20: 5126 0 0 0 GICv2 65 Level fe00b880.mailbox
23: 2098 0 0 0 GICv2 153 Level uart-pl011
24: 0 0 0 0 GICv2 150 Level fe204000.spi
25: 0 0 0 0 GICv2 129 Level vc4 hvs
26: 0 0 0 0 GICv2 149 Level fe804000.i2c
27: 2 0 0 0 GICv2 105 Level fe980000.usb, fe980000.usb, dwc2_hsotg:usb3
31: 0 0 0 0 GICv2 114 Level DMA IRQ
33: 0 0 0 0 GICv2 116 Level DMA IRQ
34: 502 0 0 0 GICv2 117 Level DMA IRQ
35: 7 0 0 0 GICv2 118 Level DMA IRQ
36: 0 0 0 0 GICv2 119 Level DMA IRQ
38: 0 0 0 0 GICv2 141 Level vc4 crtc
39: 0 0 0 0 GICv2 142 Level vc4 crtc, vc4 crtc
40: 3101 0 0 0 GICv2 133 Level vc4 crtc
41: 0 0 0 0 GICv2 138 Level vc4 crtc
42: 1 0 0 0 interrupt-controller@7ef00100 0 Edge vc4 hdmi cec tx
43: 0 0 0 0 interrupt-controller@7ef00100 1 Edge vc4 hdmi cec rx
48: 0 0 0 0 interrupt-controller@7ef00100 8 Edge vc4 hdmi cec tx
49: 0 0 0 0 interrupt-controller@7ef00100 7 Edge vc4 hdmi cec rx
54: 8644 0 0 0 GICv2 66 Level VCHIQ doorbell
55: 46652 0 0 0 GICv2 158 Level mmc1, mmc0
56: 0 0 0 0 GICv2 48 Level arm-pmu
57: 0 0 0 0 GICv2 49 Level arm-pmu
58: 0 0 0 0 GICv2 50 Level arm-pmu
59: 0 0 0 0 GICv2 51 Level arm-pmu
61: 123 1595 0 0 GICv2 189 Level eth0
62: 0 0 0 0 GICv2 190 Level eth0
68: 5436 0 0 0 GICv2 106 Level v3d
69: 0 0 0 0 GICv2 175 Level PCIe PME, aerdrv
70: 4094 0 0 0 BRCM STB PCIe MSI 524288 Edge xhci_hcd
71: 35 0 0 0 pinctrl-bcm2835 23 Edge LightSensorIrq
IPI0: 18993 36960 37471 28383 Rescheduling interrupts
IPI1: 4076 3668 3282 2370 Function call interrupts
IPI2: 0 0 0 0 CPU stop interrupts
IPI3: 0 0 0 0 CPU stop (for crash dump) interrupts
IPI4: 0 0 0 0 Timer broadcast interrupts
IPI5: 912 434 638 402 IRQ work interrupts
IPI6: 0 0 0 0 CPU wake-up interrupts
Err: 0
root@l:/home/l#
