add device class attributes (9.6)week-4

3 files changed, 92 insertions, 39 deletions

diff --git a/driver/main.c b/driver/main.c
index 2676c9a..92ff9aa 100644
--- a/driver/main.c
+++ b/driver/main.c
@@ -1,3 +1,4 @@
+// #include <linux/cdev.h>
 #include <linux/init.h>
 #include <linux/io.h>
 #include <linux/module.h>
@@ -6,7 +7,10 @@
 #include "main.h"
 #include "platform.h"
 
-struct class* class;
+// struct cdev *cdev;
+struct device *dev;
+struct class *class;
+dev_t node = 0; // do not register /dev/lork
 
 static int mod_init(void) {
 	int err;
@@ -15,22 +19,43 @@ static int mod_init(void) {
 	class = class_create("lork");
 	if (IS_ERR_OR_NULL(class)) {
 		err = PTR_ERR(class);
-		printk(KERN_ERR "class_create error %d\n", err);
 		goto free_class;
 	}
 
+	// create device (required for device attributes under /sys/class)
+	dev = device_create(class, NULL, node, NULL, "lork");
+	if (IS_ERR_OR_NULL(dev)) {
+		err = PTR_ERR(dev);
+		goto free_device;
+	}
+
 	// create platform driver
 	err = platform_driver_register(&lork_driver);
-	if (err) goto return_err;
+	if (err) goto free_platform_driver;
 
-	// create attribute under /sys/bus/platform/drivers/gpio-extern
-	err = driver_create_file(&lork_driver.driver, &attr);
-	if (err) goto return_err;
+	// create driver attribute under /sys/bus/platform/drivers/gpio-extern
+	err = driver_create_file(&lork_driver.driver, &drv_attr_int);
+	if (err) goto free_drv_attr_int;
+
+	// create device attributes under /sys/class
+	err = device_create_file(dev, &dev_attr_int);
+	if (err) goto free_dev_attr_int;
+	err = device_create_file(dev, &dev_attr_str);
+	if (err) goto free_dev_attr_str;
 
 	printk("%s() OK\n", __PRETTY_FUNCTION__);
 	return 0;
 
-return_err:
+free_dev_attr_str:
+	device_remove_file(dev, &dev_attr_str);
+free_dev_attr_int:
+	device_remove_file(dev, &dev_attr_int);
+free_drv_attr_int:
+	driver_remove_file(&lork_driver.driver, &drv_attr_int);
+free_platform_driver:
+	platform_driver_unregister(&lork_driver);
+free_device:
+	device_destroy(class, node);
 free_class:
 	class_destroy(class);
 	printk("%s() -> %d\n", __PRETTY_FUNCTION__, err);
@@ -38,8 +63,11 @@ free_class:
 }
 
 static void mod_exit(void) {
-	driver_remove_file(&lork_driver.driver, &attr);
+	device_remove_file(dev, &dev_attr_str);
+	device_remove_file(dev, &dev_attr_int);
+	driver_remove_file(&lork_driver.driver, &drv_attr_int);
 	platform_driver_unregister(&lork_driver);
+	device_destroy(class, node);
 	class_destroy(class);
 	printk("%s()\n", __PRETTY_FUNCTION__);
 }
diff --git a/driver/platform.c b/driver/platform.c
index 73d691f..b177474 100644
--- a/driver/platform.c
+++ b/driver/platform.c
@@ -42,27 +42,6 @@ int lork_probe(struct platform_device* dev) {
 	}
 	if (am33xx_pinmux == NULL) return EINVAL;
 
-	// TODO: ???
-
-	// // configure gpio mux
-	// uint32_t* conf_gpmc_a3 = ioremap(TI_AM335X_CM_GPMC_A3_ADDR, sizeof(ti_am335x_word_t));
-	// if (conf_gpmc_a3 == NULL)
-	// 	return -EINVAL;
-	// barrier();
-	// uint32_t val = ioread32(conf_gpmc_a3); rmb();
-	// val &= ~0x7;
-	// val |= 0x7;
-	// iowrite32(val, conf_gpmc_a3); wmb();
-	// iounmap(conf_gpmc_a3);
-
-	// // configure output pin
-	// ti_am335x_word_t* gpio1 = ioremap(TI_AM335X_GPIO1_ADDR, GPIO_REG_SIZE);
-	// barrier();
-	// ti_am335x_word_t oe_reg = ioread32(gpio1 + GPIO_OE); rmb();
-	// oe_reg &= ~(1<<PIN); // 0=output
-	// iowrite32(oe_reg, gpio1 + GPIO_OE); wmb();
-	// iounmap(gpio1);
-
 	printk("%s(%s)\n", __PRETTY_FUNCTION__, dev->name);
 	return 0;
 }
@@ -73,11 +52,34 @@ int lork_remove(struct platform_device* dev) {
 }
 
 unsigned int val = 0;
-ssize_t attr_show(struct device_driver* drv, char* buf) {
+ssize_t drv_attr_int_show(struct device_driver* drv, char* buf) {
 	return sprintf(buf, "%u\n", val);
 }
-ssize_t attr_store(struct device_driver* drv, const char* buf, size_t count) {
+ssize_t drv_attr_int_store(struct device_driver* drv, const char* buf, size_t count) {
 	sscanf(buf, "%u", &val);
 	return count;
 }
 
+ssize_t dev_attr_int_show(struct device* dev, struct device_attribute* _attr, char* buf) {
+	return sprintf(buf, "%u\n", val);
+}
+ssize_t dev_attr_int_store(struct device* dev, struct device_attribute* _attr, const char* buf, size_t count) {
+	sscanf(buf, "%u", &val);
+	return count;
+}
+
+char* str = NULL;
+size_t str_len = 0;
+ssize_t dev_attr_str_show(struct device* dev, struct device_attribute* _attr, char* buf) {
+	if (str == NULL) return 0;
+	strncpy(buf, str, str_len);
+	return str_len;
+}
+ssize_t dev_attr_str_store(struct device* dev, struct device_attribute* _attr, const char* buf, size_t count) {
+	if (str != NULL) kfree(str);
+	str = kmalloc(count, 0);
+	str_len = count;
+	strncpy(str, buf, str_len);
+	return count;
+}
+
diff --git a/driver/platform.h b/driver/platform.h
index cee82a7..ecac681 100644
--- a/driver/platform.h
+++ b/driver/platform.h
@@ -2,19 +2,42 @@
 
 #include <linux/types.h>
 #include <linux/platform_device.h>
+#include <linux/slab.h>
 
-ssize_t attr_show(struct device_driver*, char*);
-ssize_t attr_store(struct device_driver*, const char*, size_t);
+int lork_probe(struct platform_device*);
+int lork_remove(struct platform_device*);
 
-static struct driver_attribute attr = {
+
+ssize_t drv_attr_int_show(struct device_driver*, char*);
+ssize_t drv_attr_int_store(struct device_driver*, const char*, size_t);
+static const struct driver_attribute drv_attr_int = {
 	.attr = {
-		.name = "attr",
+		.name = "int",
 		.mode = 0644,
 	},
-	.show = attr_show,
-	.store = attr_store,
+	.show = drv_attr_int_show,
+	.store = drv_attr_int_store,
 };
 
-int lork_probe(struct platform_device*);
-int lork_remove(struct platform_device*);
+ssize_t dev_attr_int_show(struct device*, struct device_attribute*, char*);
+ssize_t dev_attr_int_store(struct device*, struct device_attribute*, const char*, size_t);
+static const struct device_attribute dev_attr_int = {
+	.attr = {
+		.name = "int",
+		.mode = 0644,
+	},
+	.show = dev_attr_int_show,
+	.store = dev_attr_int_store,
+};
+
+ssize_t dev_attr_str_show(struct device*, struct device_attribute*, char*);
+ssize_t dev_attr_str_store(struct device*, struct device_attribute*, const char*, size_t);
+static const struct device_attribute dev_attr_str = {
+	.attr = {
+		.name = "str",
+		.mode = 0644,
+	},
+	.show = dev_attr_str_show,
+	.store = dev_attr_str_store,
+};