1 files changed, 65 insertions, 0 deletions
diff --git a/arch/parisc/kernel/pdc_cons.c b/arch/parisc/kernel/pdc_cons.c
new file mode 100644
index 000000000..cf3bf8232
--- /dev/null
+++ b/arch/parisc/kernel/pdc_cons.c
@@ -0,0 +1,65 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* 
+ *    PDC early console support - use PDC firmware to dump text via boot console
+ *
+ *    Copyright (C) 2001-2022 Helge Deller <deller@gmx.de>
+ */
+
+#include <linux/console.h>
+#include <linux/init.h>
+#include <linux/serial_core.h>
+#include <linux/kgdb.h>
+#include <asm/page.h>		/* for PAGE0 */
+#include <asm/pdc.h>		/* for iodc_call() proto and friends */
+
+static void pdc_console_write(struct console *co, const char *s, unsigned count)
+{
+	int i = 0;
+
+	do {
+		i += pdc_iodc_print(s + i, count - i);
+	} while (i < count);
+}
+
+#ifdef CONFIG_KGDB
+static int kgdb_pdc_read_char(void)
+{
+	int c = pdc_iodc_getc();
+
+	return (c <= 0) ? NO_POLL_CHAR : c;
+}
+
+static void kgdb_pdc_write_char(u8 chr)
+{
+	/* no need to print char as it's shown on standard console */
+	/* pdc_iodc_print(&chr, 1); */
+}
+
+static struct kgdb_io kgdb_pdc_io_ops = {
+	.name = "kgdb_pdc",
+	.read_char = kgdb_pdc_read_char,
+	.write_char = kgdb_pdc_write_char,
+};
+#endif
+
+static int __init pdc_earlycon_setup(struct earlycon_device *device,
+				     const char *opt)
+{
+	struct console *earlycon_console;
+
+	/* If the console is duplex then copy the COUT parameters to CIN. */
+	if (PAGE0->mem_cons.cl_class == CL_DUPLEX)
+		memcpy(&PAGE0->mem_kbd, &PAGE0->mem_cons, sizeof(PAGE0->mem_cons));
+
+	earlycon_console = device->con;
+	earlycon_console->write = pdc_console_write;
+	device->port.iotype = UPIO_MEM32BE;
+
+#ifdef CONFIG_KGDB
+	kgdb_register_io_module(&kgdb_pdc_io_ops);
+#endif
+
+	return 0;
+}
+
+EARLYCON_DECLARE(pdc, pdc_earlycon_setup);