feature/char_driver Changed kernel module

- create and maintain serial driver /dev/esps0 from kernel module
- removed serial creation and destroy from rpi_init.sh
- closes PR #71
- closes PR #81
- closes PR #180

Co-authored-by: Yunhao Tian <[email protected]>
Co-authored-by: ljgabc <[email protected]>
Co-authored-by: David Rosen <[email protected]>
Co-authored-by: Yogesh Mantri <[email protected]>

Author: 5 people

esp_hosted_fg/host/linux/host_control/rpi_init.sh

@@ -66,7 +66,6 @@ wlan_init()
 {
     cd ../host_driver/esp32/
     if [ `lsmod | grep esp32 | wc -l` != "0" ]; then
-        sudo rm /dev/esps0
         if [ `lsmod | grep esp32_sdio | wc -l` != "0" ]; then
             sudo rmmod esp32_sdio &> /dev/null
             else
@@ -114,9 +113,6 @@ wlan_init()
     fi
     if [ `lsmod | grep esp32 | wc -l` != "0" ]; then
         echo "esp32 module inserted "
-        sudo mknod /dev/esps0 c 221 0
-        sudo chmod 666 /dev/esps0
-        echo "/dev/esps0 device created"
         echo "RPi init successfully completed"
     fi
 }

esp_hosted_fg/host/linux/host_driver/esp32/esp_rb.c

@@ -18,6 +18,7 @@
 
 int esp_rb_init(esp_rb_t *rb, size_t sz)
 {
+	esp_dbg("%u\n", __LINE__);
 	init_waitqueue_head(&(rb->wq));
 
 	rb->buf = kmalloc(sz, GFP_KERNEL);
@@ -40,18 +41,22 @@ int esp_rb_read_by_user(esp_rb_t *rb, const char __user *buf, size_t sz, int blo
 	int read_len = 0, temp_len = 0;
 
 	if (down_interruptible(&rb->sem)) {
+		esp_verbose("%u interrupted by signal\n", __LINE__);
 		return -ERESTARTSYS; /* Signal interruption */
 	}
 
 	while (rb->rp == rb->wp) {
 		up(&rb->sem);
 		if (block == 0) {
+			esp_verbose("%u EAGAIN\n", __LINE__);
 			return -EAGAIN;
 		}
 		if (wait_event_interruptible(rb->wq, (rb->rp != rb->wp))) {
+			esp_verbose("%u Interrupted2 by signal\n", __LINE__);
 			return -ERESTARTSYS; /* Signal interruption */
 		}
 		if (down_interruptible(&rb->sem)) {
+			esp_verbose("%u Interrupted3 by signal\n", __LINE__);
 			return -ERESTARTSYS;
 		}
 	}
@@ -93,6 +98,7 @@ int esp_rb_read_by_user(esp_rb_t *rb, const char __user *buf, size_t sz, int blo
 int get_free_space(esp_rb_t *rb)
 {
 	if (!rb || !rb->rp || !rb->wp) {
+		esp_err("%u Err fault\n", __LINE__);
 		return -EFAULT;
 	}
 	if (rb->rp == rb->wp) {
@@ -112,6 +118,7 @@ int esp_rb_write_by_kernel(esp_rb_t *rb, const char *buf, size_t sz)
 	}
 
 	if (down_interruptible(&rb->sem)) {
+		esp_verbose("%u intr by sig\n", __LINE__);
 		return -ERESTARTSYS;
 	}
 

esp_hosted_fg/host/linux/host_driver/esp32/esp_serial.c

@@ -34,11 +34,12 @@
 #include "esp_api.h"
 
 #define ESP_SERIAL_MAJOR      221
-#define ESP_SERIAL_MINOR_MAX  2
+#define ESP_SERIAL_MINOR_MAX  1
 #define ESP_RX_RB_SIZE        4096
 #define ESP_SERIAL_MAX_TX     4096
 
 static struct esp_serial_devs {
+	struct device* dev;
 	struct cdev cdev;
 	int dev_index;
 	esp_rb_t rb;
@@ -55,6 +56,7 @@ static ssize_t esp_serial_read(struct file *file, char __user *user_buffer, size
 	dev = (struct esp_serial_devs *) file->private_data;
 	ret_size = esp_rb_read_by_user(&dev->rb, user_buffer, size, !(file->f_flags & O_NONBLOCK));
 	if (ret_size == 0) {
+		esp_verbose("%u err: EAGAIN\n", __LINE__);
 		return -EAGAIN;
 	}
 	return ret_size;
@@ -188,6 +190,8 @@ int esp_serial_data_received(int dev_index, const char *data, size_t len)
 {
 	int ret = 0, ret_len = 0;
 	if (dev_index >= ESP_SERIAL_MINOR_MAX) {
+		esp_err("%u ERR: serial_dev_idx[%d] >= minor_max[%d]\n",
+				__LINE__, dev_index, ESP_SERIAL_MINOR_MAX);
 		return -EINVAL;
 	}
 
@@ -209,25 +213,41 @@ int esp_serial_data_received(int dev_index, const char *data, size_t len)
 	return ret_len;
 }
 
+static dev_t dev_first;
+static struct class *cl;
+
 int esp_serial_init(void *priv)
 {
-	int err = 0, i = 0;
+	int err = -EINVAL, i = 0;
 
 	if (!priv) {
 		esp_err("failed. NULL adapter\n");
-		return -1;
+		goto err;
 	}
 
-	err = register_chrdev_region(MKDEV(ESP_SERIAL_MAJOR, 0), ESP_SERIAL_MINOR_MAX, "esp_serial_driver");
+	/* already in correct state, ignore */
+	if (serial_init_done)
+		return 0;
+
+	err = alloc_chrdev_region(&dev_first, 0, ESP_SERIAL_MINOR_MAX, "esp_serial_driver");
 	if (err) {
-		esp_err("Error registering chrdev region %d\n", err);
-		return -1;
+		esp_err("Error alloc chrdev region %d\n", err);
+		goto err;
+	}
+
+	cl = class_create(THIS_MODULE, "esp_serial_chardrv");
+	if (IS_ERR(cl)) {
+		esp_err("Class create err[%d]\n", err);
+		err = PTR_ERR(cl);
+		goto err_class_create;
 	}
 
 	for (i = 0; i < ESP_SERIAL_MINOR_MAX; i++) {
-		cdev_init(&devs[i].cdev, &esp_serial_fops);
+		dev_t dev_num = dev_first + i;
 		devs[i].dev_index = i;
-		cdev_add(&devs[i].cdev, MKDEV(ESP_SERIAL_MAJOR, i), 1);
+		devs[i].dev = device_create(cl, NULL, dev_num, NULL, "esps%d", i);
+		cdev_init(&devs[i].cdev, &esp_serial_fops);
+		cdev_add(&devs[i].cdev, dev_num, 1);
 		esp_rb_init(&devs[i].rb, ESP_RX_RB_SIZE);
 		devs[i].priv = priv;
 		mutex_init(&devs[i].lock);
@@ -236,32 +256,40 @@ int esp_serial_init(void *priv)
 	serial_init_done = 1;
 	esp_verbose("\n");
 	return 0;
+
+err_class_create:
+	unregister_chrdev_region(dev_first, ESP_SERIAL_MINOR_MAX);
+err:
+	return err;
 }
 
 void esp_serial_cleanup(void)
 {
 	int i = 0;
 
 	for (i = 0; serial_init_done && i < ESP_SERIAL_MINOR_MAX; i++) {
+		dev_t dev_num = dev_first + i;
+		device_destroy(cl, dev_num);
 		if (!devs[i].cdev.ops)
 			cdev_del(&devs[i].cdev);
 
 		esp_rb_cleanup(&devs[i].rb);
 		mutex_destroy(&devs[i].lock);
 	}
 
-	unregister_chrdev_region(MKDEV(ESP_SERIAL_MAJOR, 0), ESP_SERIAL_MINOR_MAX);
+	class_destroy(cl);
+	unregister_chrdev_region(dev_first, ESP_SERIAL_MINOR_MAX);
 
 	serial_init_done = 0;
-	esp_verbose("\n");
+	esp_info("\n");
 	return;
 }
 
 int esp_serial_reinit(void *priv)
 {
-	esp_verbose("\n");
-	if (serial_init_done)
-		esp_serial_cleanup();
+	if (serial_init_done) {
+		return 0;
+	}
 
 	return esp_serial_init(priv);
 }

esp_hosted_fg/host/linux/host_driver/esp32/main.c

@@ -856,6 +856,7 @@ static void __exit esp_exit(void)
 #if TEST_RAW_TP
 	test_raw_tp_cleanup();
 #endif
+	esp_serial_cleanup();
 	esp_deinit_interface_layer();
 	deinit_adapter();
 

esp_hosted_fg/host/linux/host_driver/esp32/sdio/esp_sdio.c

@@ -282,7 +282,6 @@ static void esp_remove(struct sdio_func *func)
 
 	esp_info("-> Remove card\n");
 
-	esp_serial_cleanup();
 
 
 	for (prio_q_idx=0; prio_q_idx<MAX_PRIORITY_QUEUES; prio_q_idx++) {

esp_hosted_fg/host/linux/host_driver/esp32/spi/esp_spi.c

@@ -652,7 +652,6 @@ static void spi_exit(void)
 		spi_thread = NULL;
 	}
 
-	esp_serial_cleanup();
 	esp_remove_card(spi_context.adapter);
 
 	if (test_bit(ESP_SPI_GPIO_HS_IRQ_DONE, &spi_context.spi_flags)) {