基於tiny4412的Linux內核移植--- 中斷和GPIO學習（3）
2016-12-25 23:27
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作者
彭東林pengdonglin137@163.com
平臺
tiny4412 ADKLinux-4.4.4
u-boot使用的U-Boot 2010.12，是友善自帶的，爲支持設備樹和uImage做了稍許改動
簡介
前面我們實現了一種設備樹下中斷的使用方法，下面介紹第二種，這種方式本質上跟前者是一樣的，使用的是platform_bus的接口。爲了便於比較，還是以底板上面上的四個按鍵爲例分析，其中前兩個按鍵使用第二種方式，後兩個按鍵使用第一種方式。
正文
原理圖可以參考博文：基於tiny4412的Linux內核移植--- 中斷和GPIO學習（1）下面是設備樹的改動：
diff --git a/arch/arm/boot/dts/exynos4412-tiny4412.dts b/arch/arm/boot/dts/exynos4412-tiny4412.dts
index 610202a..2e69c91 100644
--- a/arch/arm/boot/dts/exynos4412-tiny4412.dts
+++ b/arch/arm/boot/dts/exynos4412-tiny4412.dts
@@ -16,6 +16,7 @@
#include <dt-bindings/gpio/gpio.h>
#include <dt-bindings/usb4640/usb4640.h>
#include <dt-bindings/pwm/pwm.h>
+#include <dt-bindings/interrupt-controller/irq.h>
#include <autoconf.h>
/ {
@@ -136,6 +137,14 @@
};
};
#endif
+
+interrupt_another: interrupt_another {
+ compatible = "tiny4412,interrupt_another";
+ interrupt-parent = <&gpx3>;
+ interrupts = <2 IRQ_TYPE_EDGE_FALLING 3 IRQ_TYPE_EDGE_FALLING>;
+ tiny4412,int_gpio0 = <&gpx3 4 GPIO_ACTIVE_HIGH>;
+ tiny4412,int_gpio1 = <&gpx3 5 GPIO_ACTIVE_HIGH>;
+ };
};
&rtc {其中，interrupts屬性值的解析需要看中斷控制器gpx3在創建irq_domain時設置的回調函數exynos_eint_irqd_ops的xlate成員。以後我們再分析。而gpio屬性的值的含義則需要看gpio控制器gpx3在創建時設置的of_xlate回調函數of_gpio_simple_xlate，這個以後分析。
下面看驅動：
#include <linux/init.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/gpio.h>
#include <linux/of.h>
#include <linux/of_gpio.h>
#include <linux/interrupt.h>
typedef struct
{
int gpio;
int irq;
char name[20];
}int_demo_data_t;
static irqreturn_t int_demo_isr_pdev(int irq, void *dev_id)
{
int_demo_data_t *data = dev_id;
printk("%s enter, %s irq: %d\n", __func__, data->name, irq);
return IRQ_HANDLED;
}
static irqreturn_t int_demo_isr_gpio(int irq, void *dev_id)
{
int_demo_data_t *data = dev_id;
printk("%s enter, %s irq: %d\n", __func__, data->name, irq);
return IRQ_HANDLED;
}
static int int_demo_probe(struct platform_device *pdev) {
struct device *dev = &pdev->dev;
int irq_gpio = -1;
int irq = -1;
int ret = 0;
int i = 0;
int_demo_data_t *data = NULL;
printk("%s enter.\n", __func__);
if (!dev->of_node) {
dev_err(dev, "no platform data.\n");
goto err0;
}
data = devm_kmalloc(dev, sizeof(*data)*4, GFP_KERNEL);
if (!data) {
dev_err(dev, "no memory.\n");
goto err0;
}
for (i = 0; i < 2; i++) {
irq = platform_get_irq(pdev, i);
sprintf(data[i].name, "tiny4412,pdev_irq_%d", i);
ret = devm_request_any_context_irq(dev, irq,
int_demo_isr_pdev, IRQF_TRIGGER_FALLING, data[i].name, data+i);
if (ret < 0) {
dev_err(dev, "Unable to claim irq %d; error %d\n",
irq, ret);
goto err0;
}
printk("request irq: %d\n", irq);
}
for (i = 0; i < 2; i++) {
sprintf(data[i+2].name, "tiny4412,int_gpio%d", i);
irq_gpio = of_get_named_gpio(dev->of_node,
data[i+2].name, 0);
if (irq_gpio < 0) {
dev_err(dev, "Looking up %s property in node %s failed %d\n",
data[i].name, dev->of_node->full_name, irq_gpio);
goto err0;
}
data[i+2].gpio = irq_gpio;
irq = gpio_to_irq(irq_gpio);
if (irq < 0) {
dev_err(dev,
"Unable to get irq number for GPIO %d, error %d\n",
irq_gpio, irq);
goto err0;
}
data[i+2].irq = irq;
printk("%s: gpio: %d ---> irq (%d)\n", __func__, irq_gpio, irq);
ret = devm_request_any_context_irq(dev, irq,
int_demo_isr_gpio, IRQF_TRIGGER_FALLING, data[i+2].name, data+i+2);
if (ret < 0) {
dev_err(dev, "Unable to claim irq %d; error %d\n",
irq, ret);
goto err0;
}
}
return 0;
err0:
return -EINVAL;
}
static int int_demo_remove(struct platform_device *pdev) {
printk("%s enter.\n", __func__);
return 0;
}
static const struct of_device_id int_demo_dt_ids[] = {
{ .compatible = "tiny4412,interrupt_another", },
{},
};
MODULE_DEVICE_TABLE(of, int_demo_dt_ids);
static struct platform_driver int_demo_driver = {
.driver = {
.name = "interrupt_another",
.of_match_table = of_match_ptr(int_demo_dt_ids),
},
.probe = int_demo_probe,
.remove = int_demo_remove,
};
static int __init int_demo_init(void)
{
int ret;
ret = platform_driver_register(&int_demo_driver);
if (ret)
printk(KERN_ERR "int demo: probe failed: %d\n", ret);
return ret;
}
module_init(int_demo_init);
static void __exit int_demo_exit(void)
{
platform_driver_unregister(&int_demo_driver);
}
module_exit(int_demo_exit);
MODULE_LICENSE("GPL");在platform_device進行populate的時候，已經對其irq資源進行了映射，這個以後分析。
驗證
加載驅動：[root@tiny4412 mnt]# insmod interrupt_another.ko [ 33.330879] int_demo_probe enter. [ 33.331896] request irq: 103 [ 33.332778] request irq: 104 [ 33.333412] int_demo_probe: gpio: 240 ---> irq (107) [ 33.334535] int_demo_probe: gpio: 241 ---> irq (108)
依次按鍵，由於沒有加消抖處理，所以依次按鍵可能會觸發多次中斷
[root@tiny4412 mnt]# [ 1244.082303] int_demo_isr_pdev enter, tiny4412,pdev_irq_0 irq: 103 [ 1244.229761] int_demo_isr_pdev enter, tiny4412,pdev_irq_0 irq: 103 [ 1245.129735] int_demo_isr_pdev enter, tiny4412,pdev_irq_1 irq: 104 [ 1245.283928] int_demo_isr_pdev enter, tiny4412,pdev_irq_1 irq: 104 [ 1246.269231] int_demo_isr_gpio enter, tiny4412,int_gpio0 irq: 107 [ 1246.476101] int_demo_isr_gpio enter, tiny4412,int_gpio0 irq: 107 [ 1247.769903] int_demo_isr_gpio enter, tiny4412,int_gpio1 irq: 108 [ 1248.034338] int_demo_isr_gpio enter, tiny4412,int_gpio1 irq: 108 [ 1248.035396] int_demo_isr_gpio enter, tiny4412,int_gpio1 irq: 108 [ 1248.035858] int_demo_isr_gpio enter, tiny4412,int_gpio1 irq: 108 [ 1248.036218] int_demo_isr_gpio enter, tiny4412,int_gpio1 irq: 108
我們再看看系統中斷資源註冊情況
[root@tiny4412 mnt]# cat /proc/interrupts CPU0 CPU1 CPU2 CPU3 36: 0 0 0 0 GIC 89 Edge mct_comp_irq 37: 16511 8820 5442 861 GIC 28 Edge MCT 42: 0 0 0 0 PMU 44 Edge s3c2410-rtc alarm 43: 0 0 0 0 PMU 45 Edge s3c2410-rtc tick 44: 34 0 0 0 GIC 107 Edge mmc0 45: 1 0 0 0 GIC 103 Edge 12480000.hsotg, 12480000.hsotg, dwc2_hsotg:usb1 46: 811 0 0 0 GIC 102 Edge ehci_hcd:usb2, ohci_hcd:usb3 47: 380 0 0 0 GIC 84 Edge 13800000.serial 51: 72 0 0 0 GIC 93 Edge 13890000.i2c 57: 1 0 0 0 GIC 67 Edge 12680000.pdma 58: 0 0 0 0 GIC 68 Edge 12690000.pdma 59: 0 0 0 0 GIC 66 Edge 12850000.mdma 71: 0 0 0 0 GIC 79 Edge 11400000.pinctrl 72: 1 0 0 0 GIC 78 Edge 11000000.pinctrl 90: 0 0 0 0 COMBINER 80 Edge 3860000.pinctrl 91: 0 0 0 0 GIC 104 Edge 106e0000.pinctrl 95: 47 0 0 0 GIC 109 Edge dw-mci 103: 8 0 0 0 exynos4210_wkup_irq_chip 2 Edge tiny4412,pdev_irq_0 104: 4 0 0 0 exynos4210_wkup_irq_chip 3 Edge tiny4412,pdev_irq_1 105: 6 0 0 0 exynos4210_wkup_irq_chip 1 Edge mma7660 106: 1 0 0 0 exynos_gpio_irq_chip 2 Edge 12530000.sdhci cd 107: 6 0 0 0 exynos4210_wkup_irq_chip 4 Edge tiny4412,int_gpio0 108: 9 0 0 0 exynos4210_wkup_irq_chip 5 Edge tiny4412,int_gpio1 IPI0: 0 1 1 1 CPU wakeup interrupts IPI1: 0 0 0 0 Timer broadcast interrupts IPI2: 841 1545 682 838 Rescheduling interrupts IPI3: 1 3 2 3 Function call interrupts IPI4: 0 1 1 1 Single function call interrupts IPI5: 0 0 0 0 CPU stop interrupts IPI6: 0 0 0 0 IRQ work interrupts IPI7: 0 0 0 0 completion interrupts
未完待續...
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