sandbox: serial: Update to use membuff
Rather than implementing our own circular queue, use membuff. This allows
us to read multiple bytes at once into the serial input.
Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/serial/sandbox.c b/drivers/serial/sandbox.c
index 8c74c3a..8e269a2 100644
--- a/drivers/serial/sandbox.c
+++ b/drivers/serial/sandbox.c
@@ -21,24 +21,18 @@
DECLARE_GLOBAL_DATA_PTR;
-/*
- *
- * serial_buf: A buffer that holds keyboard characters for the
- * Sandbox U-Boot.
- *
- * invariants:
- * serial_buf_write == serial_buf_read -> empty buffer
- * (serial_buf_write + 1) % 16 == serial_buf_read -> full buffer
- */
-static unsigned char serial_buf[16];
-static unsigned int serial_buf_write;
-static unsigned int serial_buf_read;
-
struct sandbox_serial_platdata {
int colour; /* Text colour to use for output, -1 for none */
};
+/**
+ * struct sandbox_serial_priv - Private data for this driver
+ *
+ * @buf: holds input characters available to be read by this driver
+ */
struct sandbox_serial_priv {
+ struct membuff buf;
+ char serial_buf[16];
bool start_of_line;
};
@@ -71,6 +65,7 @@
if (state->term_raw != STATE_TERM_RAW)
disable_ctrlc(1);
+ membuff_init(&priv->buf, priv->serial_buf, sizeof(priv->serial_buf));
return 0;
}
@@ -104,16 +99,12 @@
return 0;
}
-static unsigned int increment_buffer_index(unsigned int index)
-{
- return (index + 1) % ARRAY_SIZE(serial_buf);
-}
-
static int sandbox_serial_pending(struct udevice *dev, bool input)
{
- const unsigned int next_index =
- increment_buffer_index(serial_buf_write);
+ struct sandbox_serial_priv *priv = dev_get_priv(dev);
ssize_t count;
+ char *data;
+ int avail;
if (!input)
return 0;
@@ -121,26 +112,25 @@
os_usleep(100);
if (!IS_ENABLED(CONFIG_SPL_BUILD))
video_sync_all();
- if (next_index == serial_buf_read)
+ avail = membuff_putraw(&priv->buf, 100, false, &data);
+ if (!avail)
return 1; /* buffer full */
- count = os_read(0, &serial_buf[serial_buf_write], 1);
- if (count == 1)
- serial_buf_write = next_index;
+ count = os_read(0, data, avail);
+ if (count > 0)
+ membuff_putraw(&priv->buf, count, true, &data);
- return serial_buf_write != serial_buf_read;
+ return membuff_avail(&priv->buf);
}
static int sandbox_serial_getc(struct udevice *dev)
{
- int result;
+ struct sandbox_serial_priv *priv = dev_get_priv(dev);
if (!sandbox_serial_pending(dev, true))
return -EAGAIN; /* buffer empty */
- result = serial_buf[serial_buf_read];
- serial_buf_read = increment_buffer_index(serial_buf_read);
- return result;
+ return membuff_getbyte(&priv->buf);
}
#ifdef CONFIG_DEBUG_UART_SANDBOX