First commit

3 files changed, 312 insertions, 0 deletions

diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..58c7dcd
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,39 @@
+include $(TOPDIR)/rules.mk
+include $(INCLUDE_DIR)/kernel.mk
+
+# name
+PKG_NAME:=ws2811
+# version of what we are downloading
+PKG_VERSION:=1.0
+# version of this makefile
+PKG_RELEASE:=0
+
+PKG_BUILD_DIR:=$(KERNEL_BUILD_DIR)/$(PKG_NAME)
+#PKG_BUILD_DIR:=$(TOPDIR)/$(PKG_NAME)
+PKG_CHECK_FORMAT_SECURITY:=0
+
+include $(INCLUDE_DIR)/package.mk
+
+define KernelPackage/$(PKG_NAME)
+	SUBMENU:=Other modules
+	TITLE:=WS2811 leds driver
+	FILES:= $(PKG_BUILD_DIR)/ws2811.ko
+endef
+
+define KernelPackage/$(PKG_NAME)/description
+	WS2811 leds driver.
+endef
+
+MAKE_OPTS:= \
+	$(KERNEL_MAKE_FLAGS) \
+	SUBDIRS=$(PKG_BUILD_DIR)
+
+define Build/Compile
+	$(MAKE) -C "$(LINUX_DIR)" \
+	    $(MAKE_OPTS) \
+	    modules
+	cp -f $(PKG_BUILD_DIR)/$(PKG_NAME).ko ./
+	#scp $(PKG_BUILD_DIR)/$(PKG_NAME).ko root@10.13.0.245:/root/
+endef
+
+$(eval $(call KernelPackage,$(PKG_NAME)))
diff --git a/src/Makefile b/src/Makefile
new file mode 100644
index 0000000..ccdcaa6
--- /dev/null
+++ b/src/Makefile
@@ -0,0 +1 @@
+obj-m := ws2811.o
diff --git a/src/ws2811.c b/src/ws2811.c
new file mode 100644
index 0000000..ecec37b
--- /dev/null
+++ b/src/ws2811.c
@@ -0,0 +1,272 @@
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/gpio.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/ktime.h>
+#include <linux/hrtimer.h>
+#include <linux/fs.h>
+#include <linux/uaccess.h>
+#include <linux/string.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Alexey 'Cluster' Avdyukhin");
+MODULE_DESCRIPTION("WS2811 leds driver");
+MODULE_VERSION("1.0");
+
+
+// for delay
+#define T0H_TIME 50
+#define T0L_TIME 1950
+#define T1H_TIME 1500
+#define T1L_TIME 500
+
+/*
+#define T0H_TIME 250-150
+#define T0L_TIME 1000
+#define T1H_TIME 600-150
+#define T1L_TIME 650
+*/
+
+#define CLASS_NAME  "ws2811"
+
+static u8 pin = 0;
+static u16 leds = 50;
+static u8* leds_data = NULL;
+static char* device_name = "leds";
+module_param(pin, byte, 0);
+MODULE_PARM_DESC(pin,"pin number");
+module_param(leds, short, 0);
+MODULE_PARM_DESC(leds,"number of leds (default 50)");
+module_param(device_name, charp, 0);
+MODULE_PARM_DESC(device_name,"name of pseudofile (default \"leds\")");
+static int majorNumber = -1;
+static struct class*  ws2811Class  = NULL;
+static struct device* ws2811Device = NULL;
+static struct gpio_desc* pin_desc = NULL;
+DEFINE_SPINLOCK(lock);
+
+// The prototype functions for the character driver -- must come before the struct definition
+static int     dev_open(struct inode *, struct file *);
+static int     dev_release(struct inode *, struct file *);
+static ssize_t dev_read(struct file *, char *, size_t, loff_t *);
+static ssize_t dev_write(struct file *, const char *, size_t, loff_t *);
+static loff_t  dev_llseek(struct file *file,loff_t offset, int orig);
+ 
+static struct file_operations fops =
+{
+   .open = dev_open,
+   .read = dev_read,
+   .write = dev_write,
+   .release = dev_release,
+   .llseek = dev_llseek,
+};
+ 
+static void sync_leds(void)
+{
+    u8 bit, i;
+    u16 byte;
+    unsigned long flags;
+    //u64 t;
+    spin_lock_irqsave(&lock, flags);
+    gpiod_set_value(pin_desc, 0);
+    for (byte = 0; byte < 3 * leds; byte++)
+    {
+        for (bit = 0; bit < 8; bit++)
+        {            
+            for (i = 0; i < 50; i++)
+                ndelay(10); // align timer
+            if (leds_data[byte] & (1<<(7-bit)))
+            {
+                gpiod_set_value(pin_desc, 1);
+                ndelay(T1H_TIME);
+                gpiod_set_value(pin_desc, 0);
+                ndelay(T1L_TIME);
+            } else {
+                gpiod_set_value(pin_desc, 1);
+                ndelay(T0H_TIME);
+                gpiod_set_value(pin_desc, 0);
+                ndelay(T0L_TIME);
+            }
+            
+
+            //for (i = 0; i < 50; i++)
+            //ndelay(10); // align timer
+            /*
+            t = ktime_get_ns();
+            t += 500;
+            while (ktime_get_ns() < t) ;
+            if (leds_data[byte] & (1<<(7-bit)))
+            {
+                t = ktime_get_ns();
+                gpiod_set_value(pin_desc, 1);
+                t += (T1H_TIME);
+                while (ktime_get_ns() < t) ;
+                t = ktime_get_ns();
+                gpiod_set_value(pin_desc, 0);
+                t += ((T1L_TIME) - 500);
+                while (ktime_get_ns() < t) ;
+            } else {
+                t = ktime_get_ns();
+                gpiod_set_value(pin_desc, 1);
+                t += (T0H_TIME);
+                while (ktime_get_ns() < t) ;
+                t = ktime_get_ns();
+                gpiod_set_value(pin_desc, 0);
+                t += ((T0L_TIME) - 500);
+                while (ktime_get_ns() < t) ;
+            }
+            */
+        }
+    }
+    spin_unlock_irqrestore(&lock, flags);
+}
+
+static void ws2811_free(void)
+{
+    if (ws2811Class)
+    {
+        device_destroy(ws2811Class, MKDEV(majorNumber, 0));     // remove the device
+        class_unregister(ws2811Class);                          // unregister the device class
+        class_destroy(ws2811Class);                             // remove the device class
+    }
+    if (majorNumber >= 0)
+        unregister_chrdev(majorNumber, device_name);            // unregister the major number
+    if (!IS_ERR_OR_NULL(pin_desc))
+        gpiod_put(pin_desc);
+    kfree(leds_data);
+}
+
+static __init int ws2811_init(void)
+{
+    int r;
+    pin_desc = gpio_to_desc(pin);
+    if (IS_ERR(pin_desc))
+    {
+        printk(KERN_ERR "WS2811: gpiod_request result: %ld\n", PTR_ERR(pin_desc));
+        ws2811_free();
+        return -1;
+    }
+    r = gpiod_direction_output(pin_desc, 0);
+    if (r)
+    {
+        printk(KERN_ERR "WS2811: gpiod_request result: %d\n", r);
+        ws2811_free();
+        return -1;
+    }
+    leds_data = kzalloc(3 * leds, GFP_KERNEL);
+    if (!leds_data)
+    {
+        printk(KERN_ERR "WS2811: can't allocate memory for leds data\n");
+        ws2811_free();
+        return -1;
+    }
+    majorNumber = register_chrdev(0, device_name, &fops);
+    if (majorNumber<0)
+    {
+        printk(KERN_ERR "WS2811: failed to register a major number\n");
+        ws2811_free();
+        return -1;
+    }
+    // Register the device class
+    ws2811Class = class_create(THIS_MODULE, CLASS_NAME);
+    if (IS_ERR(ws2811Class))
+    {
+        ws2811_free();
+        printk(KERN_ERR "WS2811: failed to register device class\n");
+        return -1;
+    }
+    // Register the device driver
+    ws2811Device = device_create(ws2811Class, NULL, MKDEV(majorNumber, 0), NULL, device_name);
+    if (IS_ERR(ws2811Device))
+    {
+        ws2811_free();
+        printk(KERN_ERR "WS2811: failed to create the device\n");
+        return -1;
+    }
+    sync_leds();
+    printk(KERN_INFO "WS2811: driver started\n");
+    return 0;
+}
+
+static void __exit ws2811_exit(void)
+{
+    ws2811_free();    
+    printk(KERN_INFO "WS2811: driver stopped\n");
+}
+
+static int dev_open(struct inode *inodep, struct file *filep)
+{
+   return 0;
+}
+ 
+static ssize_t dev_read(struct file *filep, char *buffer, size_t len, loff_t *offset)
+{
+    loff_t max_pos = 3 * leds;
+    ssize_t r = 0;
+    while ((*offset < max_pos) && (r < len))
+    {
+        if (put_user(leds_data[*offset], buffer))
+             return -EFAULT;
+        (*offset)++;
+        r++;
+        buffer++;
+    }
+    return r;
+}
+ 
+static ssize_t dev_write(struct file *filep, const char *buffer, size_t len, loff_t *offset)
+{
+    loff_t max_pos = 3 * leds;
+    ssize_t r = 0;
+    while (r < len)
+    {
+        if (*offset >= max_pos)
+        {
+            if (r) return r;
+            return -EFAULT;
+        }
+        if (get_user(leds_data[*offset], buffer))
+        {
+            return -EFAULT;
+        }
+        (*offset)++;
+        r++;
+        buffer++;
+    }
+    sync_leds();
+    return r;
+}
+
+static loff_t dev_llseek(struct file *file, loff_t offset, int orig)
+{
+    loff_t max_pos = 3 * leds;
+    loff_t new_pos = 0;
+    switch (orig)
+    {
+        case 0: /* SEEK_SET: */
+                new_pos = offset;
+                break;
+        case 1: /* SEEK_CUR: */
+                new_pos = file->f_pos + offset;
+                break;
+        case 2: /* SEEK_END: */
+                new_pos = max_pos + offset;
+                break;
+        default:
+                return -EINVAL;
+    }
+    if ( new_pos > max_pos ) return -EINVAL;
+    if ( new_pos < 0 ) return -EINVAL;
+    file->f_pos = new_pos;
+    return new_pos;
+}
+ 
+static int dev_release(struct inode *inodep, struct file *filep)
+{
+   return 0;
+}
+
+module_init(ws2811_init);
+module_exit(ws2811_exit);