WebSVN – HelenOS – Diff – /branches/sparc/kernel/arch/sparc64/src/drivers/sgcn.c

  * Ensures that writing to the buffer and consequent update of the write pointer
  * are together one atomic operation.
  */
 SPINLOCK_INITIALIZE(sgcn_output_lock);
+/*
+ * Ensures that reading from the buffer and consequent update of the read
+ * pointer are together one atomic operation.
+ */
+SPINLOCK_INITIALIZE(sgcn_input_lock);
+/* functions referenced from definitions of I/O operations structures */
+static void sgcn_noop(chardev_t *);
-static void sgcn_putchar(struct chardev * cd, const char c);
+static void sgcn_putchar(chardev_t *, const char);
+static char sgcn_key_read(chardev_t *);
-/** character device operations */
+/** character device output operations */
-static chardev_operations_t sgcn_ops = {
+static chardev_operations_t sgcn_output_ops = {
-    .suspend = NULL,
+    .suspend = sgcn_noop,
-    .resume = NULL,
+    .resume = sgcn_noop,
     .write = sgcn_putchar,
     .read = NULL
 };
+/** character device input operations */
+static chardev_operations_t sgcn_input_ops = {
+    .suspend = sgcn_noop,
+    .resume = sgcn_noop,
+    .read = sgcn_key_read
+};
-/** SGCN character device */
+/** SGCN character output device */
 chardev_t sgcn_stdout;
+/** SGCN character input device */
+chardev_t sgcn_input;
 /**
  * Initializes the starting address of SRAM.
+ *
  * The SRAM starts 0x900000 + C bytes behind the SBBC start in the
  * physical memory, where C is the value read from the "iosram-toc"
     sgcn_buffer_begin = sram_begin + SRAM_TOC->keys[i].offset;
+}
 /**
+ * Default suspend/resume operation for the input device.
+ */
+static void sgcn_noop(chardev_t *d)
+{
+}
+/**
  * Writes a single character to the SGCN (circular) output buffer
  * and updates the output write pointer so that SGCN gets to know
  * that the character has been written.
  */
 static void sgcn_do_putchar(const char c)
     spinlock_unlock(&sgcn_output_lock);
+}
 /**
+ * Called when actively reading the character. Not implemented yet.
+ */
+static char sgcn_key_read(chardev_t *d)
+{
+    return (char) 0;
+}
+/**
+ * Function regularly called by the keyboard polling thread. Finds out whether
+ * there are some unread characters in the input queue. If so, it picks them up
+ * and sends them to the upper layers of HelenOS.
+ */
+void sgcn_poll(void)
+{
+    spinlock_lock(&sgcn_input_lock);
+    char c;
+    uint32_t begin = SGCN_BUFFER_HEADER->in_begin;
+    uint32_t end = SGCN_BUFFER_HEADER->in_end;
+    uint32_t size = end - begin;
+    /* we need pointers to volatile variables */
+    volatile char *buf_ptr = (volatile char *)
+        SGCN_BUFFER(char, SGCN_BUFFER_HEADER->in_rdptr);
+    volatile uint32_t *in_wrptr_ptr = &(SGCN_BUFFER_HEADER->in_wrptr);
+    volatile uint32_t *in_rdptr_ptr = &(SGCN_BUFFER_HEADER->in_rdptr);
+    while (*in_rdptr_ptr != *in_wrptr_ptr) {
+        c = *buf_ptr;
+        *in_rdptr_ptr = (((*in_rdptr_ptr) - begin + 1) % size) + begin;
+        buf_ptr = (volatile char *)
+            SGCN_BUFFER(char, SGCN_BUFFER_HEADER->in_rdptr);
+        chardev_push_character(&sgcn_input, c);
+        if (c == '\r')
+            chardev_push_character(&sgcn_input, '\n');
+    }
+    spinlock_unlock(&sgcn_input_lock);
+}
+/**
  * A public function which initializes I/O from/to Serengeti console
  * and sets it as a default input/output.
  */
 void sgcn_init(void)
+{
     sgcn_buffer_begin_init();
-    chardev_initialize("sgcn_output", &sgcn_stdout, &sgcn_ops);
+    chardev_initialize("sgcn_output", &sgcn_stdout, &sgcn_output_ops);
     stdout = &sgcn_stdout;
-    printf("SGCN buffer begin = %d, in read ptr = %" PRIu32 ".", sgcn_buffer_begin, SGCN_BUFFER_HEADER->in_wrptr);
+    chardev_initialize("sgcn_input", &sgcn_input, &sgcn_input_ops);
+    stdin = &sgcn_input;
+}
 /** @}
  */

Subversion Repositories HelenOS

(root)/branches/sparc/kernel/arch/sparc64/src/drivers/sgcn.c – Rev 3502 → 3514