serial: uart_native_pty_bottom: length parameter

Add a length parameter to the poll in read function so that data can be
read in larger chunks.

Signed-off-by: Jordan Yates <jordan@embeint.com>

drivers/serial/uart_native_pty.c

@@ -170,13 +170,11 @@ static int np_uart_stdin_poll_in(const struct device *dev, unsigned char *p_char
 		return -1;
 	}
 
-	rc = np_uart_stdin_poll_in_bottom(in_f, p_char);
+	rc = np_uart_stdin_poll_in_bottom(in_f, p_char, 1);
 	if (rc == -2) {
 		disconnected = true;
-		return -1;
 	}
-
-	return rc;
+	return rc == 1 ? 0 : -1;
 }
 
 /**

drivers/serial/uart_native_pty_bottom.c

@@ -32,12 +32,13 @@
  *
  * @param in_f   Input file descriptor
  * @param p_char Pointer to character.
+ * @param len    Maximum number of characters to read.
  *
- * @retval 0 If a character arrived and was stored in p_char
+ * @retval >0 Number of characters actually read
  * @retval -1 If no character was available to read
  * @retval -2 if the stdin is disconnected
  */
-int np_uart_stdin_poll_in_bottom(int in_f, unsigned char *p_char)
+int np_uart_stdin_poll_in_bottom(int in_f, unsigned char *p_char, int len)
 {
 	if (feof(stdin)) {
 		/*
@@ -64,12 +65,12 @@ int np_uart_stdin_poll_in_bottom(int in_f, unsigned char *p_char)
 		ERROR("%s: Error on select ()\n", __func__);
 	}
 
-	n = read(in_f, p_char, 1);
+	n = read(in_f, p_char, len);
 	if ((n == -1) || (n == 0)) {
 		return -1;
 	}
 
-	return 0;
+	return n;
 }
 
 /**

drivers/serial/uart_native_pty_bottom.h

@@ -20,7 +20,7 @@ extern "C" {
 
 /* Note: None of these functions are public interfaces. But internal to the native ptty driver */
 
-int np_uart_stdin_poll_in_bottom(int in_f, unsigned char *p_char);
+int np_uart_stdin_poll_in_bottom(int in_f, unsigned char *p_char, int len);
 int np_uart_slave_connected(int fd);
 int np_uart_open_pty(const char *uart_name, const char *auto_attach_cmd,
 		     bool do_auto_attach, bool wait_pts);