platform : show and store example

Author: 54shady

debug/platform_driver_test/Makefile

@@ -3,9 +3,9 @@
 # DEBUG = y
 
 # Usage
-# make CC=<your_compiler_path> KERNELDIR=<your_kernel_dir>
+# make CROSS_COMPILE=<cross_compiler_prefix> KERNEL_DIR=<your_kernel_dir> KERNEL_BUID_OUTPUT=<kernel_buid_output>
 #
-# make CC=/home/zeroway/3288/src/3288_4.4/prebuilts/gcc/linux-x86/arm/arm-eabi-4.6/bin/arm-eabi-gcc KERNELDIR=/home/zeroway/3288/src/3288_4.4/kernel
+# make CROSS_COMPILE=/home/zeroway/3288/51/src/3288_5.1_v2/prebuilts/gcc/linux-x86/arm/arm-eabi-4.6/bin/arm-eabi- KERNEL_DIR=/home/zeroway/3288/51/src/3288_5.1_v2/kernel KERNEL_BUID_OUTPUT=/home/zeroway/3288/51/src/3288_5.1_v2/out/target/product/rk3288/obj/KERNEL
 
 # Add your debugging flag (or not) to CFLAGS
 ifeq ($(DEBUG),y)
@@ -15,12 +15,15 @@ DEBFLAGS = -O2
 endif
 
 obj-m := test_pf.o
-KERNELDIR ?= /lib/modules/$(shell uname -r)/build
-CC ?= gcc
+obj-m += show_store_pf.o
+KERNEL_DIR ?= /lib/modules/$(shell uname -r)/build
+KERNEL_BUID_OUTPUT ?=$(KERNEL_DIR)
+CC = $(CROSS_COMPILE)gcc
+LD = $(CROSS_COMPILE)ld
 PWD := $(shell pwd)
 
 modules:
-	$(MAKE) -C $(KERNELDIR) M=$(PWD) modules
+	$(MAKE) -C $(KERNEL_DIR) M=$(PWD) O=$(KERNEL_BUID_OUTPUT) modules
 
 clean:
 	rm -rf *.o *~ core .depend .*.cmd *.ko *.mod.c .tmp_versions modules.order Module.symvers

debug/platform_driver_test/README.md

@@ -7,3 +7,20 @@
 在驱动中如何使用下图中的VCC_TP,详见代码
 
 ![VCC_TP](./VCC_TP.png)
+
+# show_store_pf.c
+
+	device attr show and store
+
+## usage
+
+把dtsi文件包含到所使用的dts里
+
+	#include "show_store_pf.dtsi"
+
+## debug
+
+输入3个值并查看
+
+	echo 1 3 4 > /sys/devices/my_test_node.23/BBBBB_debug
+	cat /sys/devices/my_test_node.23/BBBBB_debug

debug/platform_driver_test/show_store_pf.c

@@ -0,0 +1,86 @@
+#include <linux/of.h>
+#include <linux/init.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+static int g_x = -1;
+static int g_y = -1;
+static int g_z = -1;
+
+static ssize_t BBBBB_debug_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	printk("x = %d y = %d z = %d\n", g_x, g_y, g_z);
+	return 0;
+}
+
+static ssize_t BBBBB_debug_store(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t count)
+{
+	sscanf(buf, "%d %d %d", &g_x, &g_y, &g_z);
+	return count;
+}
+
+static DEVICE_ATTR(BBBBB_debug, S_IRUGO | S_IWUSR, BBBBB_debug_show, BBBBB_debug_store);
+
+static struct attribute *BBBBB_attrs[] = {
+	&dev_attr_BBBBB_debug.attr,
+	NULL,
+};
+
+static const struct attribute_group BBBBB_attr_group = {
+	.attrs = BBBBB_attrs,
+};
+
+static int AAAAA_platform_probe(struct platform_device *pdev)
+{
+	int ret;
+
+	ret = sysfs_create_group(&pdev->dev.kobj, &BBBBB_attr_group);
+	if (ret) {
+		printk("failed to create sysfs device attributes\n");
+		return -1;
+	}
+	return 0;
+}
+
+static const struct of_device_id AAAAA_platform_dt_ids[] = {
+	{ .compatible = "test_platform", },
+	{}
+};
+
+static int AAAAA_platform_remove(struct platform_device *pdev)
+{
+	int ret;
+
+	sysfs_remove_group(&pdev->dev.kobj, &BBBBB_attr_group);
+
+	printk("%s, %d\n", __FUNCTION__, __LINE__);
+	return 0;
+}
+
+static struct platform_driver AAAAA_platform_driver = {
+	.driver		= {
+		.name	= "test platform driver",
+		.owner	= THIS_MODULE,
+		.of_match_table = of_match_ptr(AAAAA_platform_dt_ids),
+	},
+	.probe		= AAAAA_platform_probe,
+};
+
+static int AAAAA_platform_init(void)
+{
+	return platform_driver_register(&AAAAA_platform_driver);
+}
+
+static void AAAAA_platform_exit(void)
+{
+	platform_driver_unregister(&AAAAA_platform_driver);
+}
+
+module_init(AAAAA_platform_init);
+module_exit(AAAAA_platform_exit);
+MODULE_LICENSE("GPL");

debug/platform_driver_test/show_store_pf.dtsi

@@ -0,0 +1,5 @@
+/ {
+	my_test_node {
+		compatible = "test_platform";
+	};
+};