[POWERPC] Add Marvell mv64x60 udbg putc/getc functions

Commit 69331af, "Fixes and cleanups for earlyprintk aka boot console",
resulted in printk output prior to the initialization of the mpsc
console driver not being printed.  That commit causes the mpsc's
CON_PRINTBUFFER flag to be cleared since udbg should have printed
the previous output.

I guess we can no longer ignore udbg. :)

This patch provides udbg_putc() and udbg_getc() functions for the
Marvell mv64x60 chips. These functions are enabled if an mv64x60
port is to be used as the console as determined from the device tree.

Signed-off-by: Dale Farnsworth <dale@farnsworth.org>
Acked-by: Mark A. Greer <mgreer@mvista.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 152 insertions, 0 deletions

diff --git a/arch/powerpc/sysdev/mv64x60_udbg.c b/arch/powerpc/sysdev/mv64x60_udbg.c
new file mode 100644
index 000000000000..367e7b13ec00
--- /dev/null
+++ b/arch/powerpc/sysdev/mv64x60_udbg.c
@@ -0,0 +1,152 @@
+/*
+ * udbg serial input/output routines for the Marvell MV64x60 (Discovery).
+ *
+ * Author: Dale Farnsworth <dale@farnsworth.org>
+ *
+ * 2007 (c) MontaVista Software, Inc.  This file is licensed under
+ * the terms of the GNU General Public License version 2.  This program
+ * is licensed "as is" without any warranty of any kind, whether express
+ * or implied.
+ */
+
+#include <asm/io.h>
+#include <asm/prom.h>
+#include <asm/udbg.h>
+
+#include <sysdev/mv64x60.h>
+
+#define MPSC_0_CR1_OFFSET	0x000c
+
+#define MPSC_0_CR2_OFFSET	0x0010
+#define MPSC_CHR_2_TCS		(1 << 9)
+
+#define MPSC_0_CHR_10_OFFSET	0x0030
+
+#define MPSC_INTR_CAUSE_OFF_0	0x0004
+#define MPSC_INTR_CAUSE_OFF_1	0x000c
+#define MPSC_INTR_CAUSE_RCC	(1<<6)
+
+static void __iomem *mpsc_base;
+static void __iomem *mpsc_intr_cause;
+
+static void mv64x60_udbg_putc(char c)
+{
+	if (c == '\n')
+		mv64x60_udbg_putc('\r');
+
+	while(in_le32(mpsc_base + MPSC_0_CR2_OFFSET) & MPSC_CHR_2_TCS)
+		;
+	out_le32(mpsc_base + MPSC_0_CR1_OFFSET, c);
+	out_le32(mpsc_base + MPSC_0_CR2_OFFSET, MPSC_CHR_2_TCS);
+}
+
+static int mv64x60_udbg_testc(void)
+{
+	return (in_le32(mpsc_intr_cause) & MPSC_INTR_CAUSE_RCC) != 0;
+}
+
+static int mv64x60_udbg_getc(void)
+{
+	int cause = 0;
+	int c;
+
+	while (!mv64x60_udbg_testc())
+		;
+
+	c = in_8(mpsc_base + MPSC_0_CHR_10_OFFSET + 2);
+	out_8(mpsc_base + MPSC_0_CHR_10_OFFSET + 2, c);
+	out_le32(mpsc_intr_cause, cause & ~MPSC_INTR_CAUSE_RCC);
+	return c;
+}
+
+static int mv64x60_udbg_getc_poll(void)
+{
+	if (!mv64x60_udbg_testc())
+		return -1;
+
+	return mv64x60_udbg_getc();
+}
+
+static void mv64x60_udbg_init(void)
+{
+	struct device_node *np, *mpscintr, *stdout = NULL;
+	const char *path;
+	const phandle *ph;
+	struct resource r[2];
+	const int *block_index;
+	int intr_cause_offset;
+	int err;
+
+	path = of_get_property(of_chosen, "linux,stdout-path", NULL);
+	if (!path)
+		return;
+
+	stdout = of_find_node_by_path(path);
+	if (!stdout)
+		return;
+
+	for (np = NULL;
+	     (np = of_find_compatible_node(np, "serial", "marvell,mpsc")); )
+		if (np == stdout)
+			break;
+
+	of_node_put(stdout);
+	if (!np)
+		return;
+
+	block_index = of_get_property(np, "block-index", NULL);
+	if (!block_index)
+		goto error;
+
+	switch (*block_index) {
+	case 0:
+		intr_cause_offset = MPSC_INTR_CAUSE_OFF_0;
+		break;
+	case 1:
+		intr_cause_offset = MPSC_INTR_CAUSE_OFF_1;
+		break;
+	default:
+		goto error;
+	}
+
+	err = of_address_to_resource(np, 0, &r[0]);
+	if (err)
+		goto error;
+
+	ph = of_get_property(np, "mpscintr", NULL);
+	mpscintr = of_find_node_by_phandle(*ph);
+	if (!mpscintr)
+		goto error;
+
+	err = of_address_to_resource(mpscintr, 0, &r[1]);
+	of_node_put(mpscintr);
+	if (err)
+		goto error;
+
+	of_node_put(np);
+
+	mpsc_base = ioremap(r[0].start, r[0].end - r[0].start + 1);
+	if (!mpsc_base)
+		return;
+
+	mpsc_intr_cause = ioremap(r[1].start, r[1].end - r[1].start + 1);
+	if (!mpsc_intr_cause) {
+		iounmap(mpsc_base);
+		return;
+	}
+	mpsc_intr_cause += intr_cause_offset;
+
+	udbg_putc = mv64x60_udbg_putc;
+	udbg_getc = mv64x60_udbg_getc;
+	udbg_getc_poll = mv64x60_udbg_getc_poll;
+
+	return;
+
+error:
+	of_node_put(np);
+}
+
+void mv64x60_init_early(void)
+{
+	mv64x60_udbg_init();
+}