[PATCH] powerpc: Move udbg code to arch/powerpc

Since the udbg code in ppc64 has no ppc32 equivalent, move it straight
over into arch/powerpc (and include/asm-powerpc for udbg.h).  In time,
we probably want to meld the various bits and pieces of 32-bit early
debugging code into udbg, but for now only include it on
CONFIG_PPC64=y builds.  The only change during the move is to
standardise the protecting #ifdef/#define in udbg.h, and move its
banner comment above the initial #ifdef (which seems to be normal
practice).

Built and booted on POWER5 LPAR (ARCH=powerpc and ARCH=ppc64).  Built
for 32bit multiplatform (ARCH=powerpc).

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 123 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/udbg_16550.c b/arch/powerpc/kernel/udbg_16550.c
new file mode 100644
index 000000000000..9313574ab935
--- /dev/null
+++ b/arch/powerpc/kernel/udbg_16550.c
@@ -0,0 +1,123 @@
+/*
+ * udbg for for NS16550 compatable serial ports
+ *
+ * Copyright (C) 2001-2005 PPC 64 Team, IBM Corp
+ *
+ *      This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License
+ *      as published by the Free Software Foundation; either version
+ *      2 of the License, or (at your option) any later version.
+ */
+#include <linux/config.h>
+#include <linux/types.h>
+#include <asm/udbg.h>
+#include <asm/io.h>
+
+extern u8 real_readb(volatile u8 __iomem  *addr);
+extern void real_writeb(u8 data, volatile u8 __iomem *addr);
+
+struct NS16550 {
+	/* this struct must be packed */
+	unsigned char rbr;  /* 0 */
+	unsigned char ier;  /* 1 */
+	unsigned char fcr;  /* 2 */
+	unsigned char lcr;  /* 3 */
+	unsigned char mcr;  /* 4 */
+	unsigned char lsr;  /* 5 */
+	unsigned char msr;  /* 6 */
+	unsigned char scr;  /* 7 */
+};
+
+#define thr rbr
+#define iir fcr
+#define dll rbr
+#define dlm ier
+#define dlab lcr
+
+#define LSR_DR   0x01  /* Data ready */
+#define LSR_OE   0x02  /* Overrun */
+#define LSR_PE   0x04  /* Parity error */
+#define LSR_FE   0x08  /* Framing error */
+#define LSR_BI   0x10  /* Break */
+#define LSR_THRE 0x20  /* Xmit holding register empty */
+#define LSR_TEMT 0x40  /* Xmitter empty */
+#define LSR_ERR  0x80  /* Error */
+
+static volatile struct NS16550 __iomem *udbg_comport;
+
+static void udbg_550_putc(unsigned char c)
+{
+	if (udbg_comport) {
+		while ((in_8(&udbg_comport->lsr) & LSR_THRE) == 0)
+			/* wait for idle */;
+		out_8(&udbg_comport->thr, c);
+		if (c == '\n')
+			udbg_550_putc('\r');
+	}
+}
+
+static int udbg_550_getc_poll(void)
+{
+	if (udbg_comport) {
+		if ((in_8(&udbg_comport->lsr) & LSR_DR) != 0)
+			return in_8(&udbg_comport->rbr);
+		else
+			return -1;
+	}
+	return -1;
+}
+
+static unsigned char udbg_550_getc(void)
+{
+	if (udbg_comport) {
+		while ((in_8(&udbg_comport->lsr) & LSR_DR) == 0)
+			/* wait for char */;
+		return in_8(&udbg_comport->rbr);
+	}
+	return 0;
+}
+
+void udbg_init_uart(void __iomem *comport, unsigned int speed)
+{
+	u16 dll = speed ? (115200 / speed) : 12;
+
+	if (comport) {
+		udbg_comport = (struct NS16550 __iomem *)comport;
+		out_8(&udbg_comport->lcr, 0x00);
+		out_8(&udbg_comport->ier, 0xff);
+		out_8(&udbg_comport->ier, 0x00);
+		out_8(&udbg_comport->lcr, 0x80);	/* Access baud rate */
+		out_8(&udbg_comport->dll, dll & 0xff);	/* 1 = 115200,  2 = 57600,
+							   3 = 38400, 12 = 9600 baud */
+		out_8(&udbg_comport->dlm, dll >> 8);	/* dll >> 8 which should be zero
+							   for fast rates; */
+		out_8(&udbg_comport->lcr, 0x03);	/* 8 data, 1 stop, no parity */
+		out_8(&udbg_comport->mcr, 0x03);	/* RTS/DTR */
+		out_8(&udbg_comport->fcr ,0x07);	/* Clear & enable FIFOs */
+		udbg_putc = udbg_550_putc;
+		udbg_getc = udbg_550_getc;
+		udbg_getc_poll = udbg_550_getc_poll;
+	}
+}
+
+#ifdef CONFIG_PPC_MAPLE
+void udbg_maple_real_putc(unsigned char c)
+{
+	if (udbg_comport) {
+		while ((real_readb(&udbg_comport->lsr) & LSR_THRE) == 0)
+			/* wait for idle */;
+		real_writeb(c, &udbg_comport->thr); eieio();
+		if (c == '\n')
+			udbg_maple_real_putc('\r');
+	}
+}
+
+void udbg_init_maple_realmode(void)
+{
+	udbg_comport = (volatile struct NS16550 __iomem *)0xf40003f8;
+
+	udbg_putc = udbg_maple_real_putc;
+	udbg_getc = NULL;
+	udbg_getc_poll = NULL;
+}
+#endif /* CONFIG_PPC_MAPLE */