MN10300: Allow KGDB to use the MN10300 serial ports
Allow KGDB to use the MN10300 serial ports through the polled I/O interface
provided via the TTY/serial layer and the kgdboc driver. This allows the
kernel to be started with something like:
kgdboc=ttySM0,115200
added to the command line.
Signed-off-by: David Howells <dhowells@redhat.com>
diff --git a/arch/mn10300/kernel/mn10300-serial.c b/arch/mn10300/kernel/mn10300-serial.c
index 93c5373..efca426 100644
--- a/arch/mn10300/kernel/mn10300-serial.c
+++ b/arch/mn10300/kernel/mn10300-serial.c
@@ -119,6 +119,10 @@
static void mn10300_serial_config_port(struct uart_port *, int);
static int mn10300_serial_verify_port(struct uart_port *,
struct serial_struct *);
+#ifdef CONFIG_CONSOLE_POLL
+static void mn10300_serial_poll_put_char(struct uart_port *, unsigned char);
+static int mn10300_serial_poll_get_char(struct uart_port *);
+#endif
static const struct uart_ops mn10300_serial_ops = {
.tx_empty = mn10300_serial_tx_empty,
@@ -138,6 +142,10 @@
.request_port = mn10300_serial_request_port,
.config_port = mn10300_serial_config_port,
.verify_port = mn10300_serial_verify_port,
+#ifdef CONFIG_CONSOLE_POLL
+ .poll_put_char = mn10300_serial_poll_put_char,
+ .poll_get_char = mn10300_serial_poll_get_char,
+#endif
};
static irqreturn_t mn10300_serial_interrupt(int irq, void *dev_id);
@@ -1634,3 +1642,70 @@
console_initcall(mn10300_serial_console_init);
#endif
+
+#ifdef CONFIG_CONSOLE_POLL
+/*
+ * Polled character reception for the kernel debugger
+ */
+static int mn10300_serial_poll_get_char(struct uart_port *_port)
+{
+ struct mn10300_serial_port *port =
+ container_of(_port, struct mn10300_serial_port, uart);
+ unsigned ix;
+ u8 st, ch;
+
+ _enter("%s", port->name);
+
+ do {
+ /* pull chars out of the hat */
+ ix = port->rx_outp;
+ if (ix == port->rx_inp)
+ return NO_POLL_CHAR;
+
+ ch = port->rx_buffer[ix++];
+ st = port->rx_buffer[ix++];
+ smp_rmb();
+ port->rx_outp = ix & (MNSC_BUFFER_SIZE - 1);
+
+ } while (st & (SC01STR_FEF | SC01STR_PEF | SC01STR_OEF));
+
+ return ch;
+}
+
+
+/*
+ * Polled character transmission for the kernel debugger
+ */
+static void mn10300_serial_poll_put_char(struct uart_port *_port,
+ unsigned char ch)
+{
+ struct mn10300_serial_port *port =
+ container_of(_port, struct mn10300_serial_port, uart);
+ u8 intr, tmp;
+
+ /* wait for the transmitter to finish anything it might be doing (and
+ * this includes the virtual DMA handler, so it might take a while) */
+ while (*port->_status & (SC01STR_TBF | SC01STR_TXF))
+ continue;
+
+ /* disable the Tx ready interrupt */
+ intr = *port->_intr;
+ *port->_intr = intr & ~SC01ICR_TI;
+ tmp = *port->_intr;
+
+ if (ch == 0x0a) {
+ *(u8 *) port->_txb = 0x0d;
+ while (*port->_status & SC01STR_TBF)
+ continue;
+ }
+
+ *(u8 *) port->_txb = ch;
+ while (*port->_status & SC01STR_TBF)
+ continue;
+
+ /* restore the Tx interrupt flag */
+ *port->_intr = intr;
+ tmp = *port->_intr;
+}
+
+#endif /* CONFIG_CONSOLE_POLL */