[PATCH] powerpc: Unify udbg (#2)

This patch unifies udbg for both ppc32 and ppc64 when building the
merged achitecture. xmon now has a single "back end". The powermac udbg
stuff gets enriched with some ADB capabilities and btext output. In
addition, the early_init callback is now called on ppc32 as well,
approx. in the same order as ppc64 regarding device-tree manipulations.
The init sequences of ppc32 and ppc64 are getting closer, I'll unify
them in a later patch.

For now, you can force udbg to the scc using "sccdbg" or to btext using
"btextdbg" on powermacs. I'll implement a cleaner way of forcing udbg
output to something else than the autodetected OF output device in a
later patch.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 218 insertions, 0 deletions

diff --git a/arch/powerpc/platforms/powermac/udbg_adb.c b/arch/powerpc/platforms/powermac/udbg_adb.c
new file mode 100644
index 00000000000..e51de55b2d6
--- /dev/null
+++ b/arch/powerpc/platforms/powermac/udbg_adb.c
@@ -0,0 +1,218 @@
+#include <linux/config.h>
+#include <linux/string.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/bitops.h>
+#include <linux/ptrace.h>
+#include <linux/adb.h>
+#include <linux/pmu.h>
+#include <linux/cuda.h>
+#include <asm/machdep.h>
+#include <asm/io.h>
+#include <asm/page.h>
+#include <asm/xmon.h>
+#include <asm/prom.h>
+#include <asm/bootx.h>
+#include <asm/machdep.h>
+#include <asm/errno.h>
+#include <asm/pmac_feature.h>
+#include <asm/processor.h>
+#include <asm/delay.h>
+#include <asm/btext.h>
+#include <asm/time.h>
+#include <asm/udbg.h>
+
+/*
+ * This implementation is "special", it can "patch" the current
+ * udbg implementation and work on top of it. It must thus be
+ * initialized last
+ */
+
+static void (*udbg_adb_old_putc)(char c);
+static char (*udbg_adb_old_getc)(void);
+static int (*udbg_adb_old_getc_poll)(void);
+
+static enum {
+	input_adb_none,
+	input_adb_pmu,
+	input_adb_cuda,
+} input_type = input_adb_none;
+
+static int udbg_adb_use_btext;
+
+int xmon_wants_key, xmon_adb_keycode;
+
+static inline void udbg_adb_poll(void)
+{
+#ifdef CONFIG_ADB_PMU
+	if (input_type == input_adb_pmu)
+		pmu_poll_adb();
+#endif /* CONFIG_ADB_PMU */
+#ifdef CONFIG_ADB_CUDA
+	if (input_type == input_adb_cuda)
+		cuda_poll();
+#endif /* CONFIG_ADB_CUDA */
+}
+
+#ifdef CONFIG_BOOTX_TEXT
+static int xmon_adb_shiftstate;
+
+static unsigned char xmon_keytab[128] =
+	"asdfhgzxcv\000bqwer"				/* 0x00 - 0x0f */
+	"yt123465=97-80]o"				/* 0x10 - 0x1f */
+	"u[ip\rlj'k;\\,/nm."				/* 0x20 - 0x2f */
+	"\t `\177\0\033\0\0\0\0\0\0\0\0\0\0"		/* 0x30 - 0x3f */
+	"\0.\0*\0+\0\0\0\0\0/\r\0-\0"			/* 0x40 - 0x4f */
+	"\0\0000123456789\0\0\0";			/* 0x50 - 0x5f */
+
+static unsigned char xmon_shift_keytab[128] =
+	"ASDFHGZXCV\000BQWER"				/* 0x00 - 0x0f */
+	"YT!@#$^%+(&_*)}O"				/* 0x10 - 0x1f */
+	"U{IP\rLJ\"K:|<?NM>"				/* 0x20 - 0x2f */
+	"\t ~\177\0\033\0\0\0\0\0\0\0\0\0\0"		/* 0x30 - 0x3f */
+	"\0.\0*\0+\0\0\0\0\0/\r\0-\0"			/* 0x40 - 0x4f */
+	"\0\0000123456789\0\0\0";			/* 0x50 - 0x5f */
+
+static char udbg_adb_local_getc(void)
+{
+	int k, t, on;
+
+	xmon_wants_key = 1;
+	for (;;) {
+		xmon_adb_keycode = -1;
+		t = 0;
+		on = 0;
+		k = -1;
+		do {
+			if (--t < 0) {
+				on = 1 - on;
+				btext_drawchar(on? 0xdb: 0x20);
+				btext_drawchar('\b');
+				t = 200000;
+			}
+			udbg_adb_poll();
+			if (udbg_adb_old_getc_poll)
+				k = udbg_adb_old_getc_poll();
+		} while (k == -1 && xmon_adb_keycode == -1);
+		if (on)
+			btext_drawstring(" \b");
+		if (k != -1)
+			return k;
+		k = xmon_adb_keycode;
+
+		/* test for shift keys */
+		if ((k & 0x7f) == 0x38 || (k & 0x7f) == 0x7b) {
+			xmon_adb_shiftstate = (k & 0x80) == 0;
+			continue;
+		}
+		if (k >= 0x80)
+			continue;	/* ignore up transitions */
+		k = (xmon_adb_shiftstate? xmon_shift_keytab: xmon_keytab)[k];
+		if (k != 0)
+			break;
+	}
+	xmon_wants_key = 0;
+	return k;
+}
+#endif /* CONFIG_BOOTX_TEXT */
+
+static char udbg_adb_getc(void)
+{
+#ifdef CONFIG_BOOTX_TEXT
+	if (udbg_adb_use_btext && input_type != input_adb_none)
+		return udbg_adb_local_getc();
+#endif
+	if (udbg_adb_old_getc)
+		return udbg_adb_old_getc();
+	return -1;
+}
+
+/* getc_poll() is not really used, unless you have the xmon-over modem
+ * hack that doesn't quite concern us here, thus we just poll the low level
+ * ADB driver to prevent it from timing out and call back the original poll
+ * routine.
+ */
+static int udbg_adb_getc_poll(void)
+{
+	udbg_adb_poll();
+
+	if (udbg_adb_old_getc_poll)
+		return udbg_adb_old_getc_poll();
+	return -1;
+}
+
+static void udbg_adb_putc(char c)
+{
+#ifdef CONFIG_BOOTX_TEXT
+	if (udbg_adb_use_btext)
+		btext_drawchar(c);
+#endif
+	if (udbg_adb_old_putc)
+		return udbg_adb_old_putc(c);
+}
+
+void udbg_adb_init_early(void)
+{
+#ifdef CONFIG_BOOTX_TEXT
+	if (btext_find_display(1) == 0) {
+		udbg_adb_use_btext = 1;
+		udbg_putc = udbg_adb_putc;
+	}
+#endif
+}
+
+int udbg_adb_init(int force_btext)
+{
+	struct device_node *np;
+
+	/* Capture existing callbacks */
+	udbg_adb_old_putc = udbg_putc;
+	udbg_adb_old_getc = udbg_getc;
+	udbg_adb_old_getc_poll = udbg_getc_poll;
+
+	/* Check if our early init was already called */
+	if (udbg_adb_old_putc == udbg_adb_putc ||
+	    udbg_adb_old_putc == btext_drawchar)
+		udbg_adb_old_putc = NULL;
+
+	/* Set ours as output */
+	udbg_putc = udbg_adb_putc;
+	udbg_getc = udbg_adb_getc;
+	udbg_getc_poll = udbg_adb_getc_poll;
+
+#ifdef CONFIG_BOOTX_TEXT
+	/* Check if we should use btext output */
+	if (btext_find_display(force_btext) == 0)
+		udbg_adb_use_btext = 1;
+#endif
+
+	/* See if there is a keyboard in the device tree with a parent
+	 * of type "adb". If not, we return a failure, but we keep the
+	 * bext output set for now
+	 */
+	for (np = NULL; (np = of_find_node_by_name(np, "keyboard")) != NULL;) {
+		struct device_node *parent = of_get_parent(np);
+		int found = (parent && !strcmp(parent->type, "adb") == 0);
+		of_node_put(parent);
+		if (found)
+			break;
+	}
+	if (np == NULL)
+		return -ENODEV;
+	of_node_put(np);
+
+#ifdef CONFIG_ADB_PMU
+	if (find_via_pmu())
+		input_type = input_adb_pmu;
+#endif
+#ifdef CONFIG_ADB_CUDA
+	if (find_via_cuda())
+		input_type = input_adb_cuda;
+#endif
+
+	/* Same as above: nothing found, keep btext set for output */
+	if (input_type == input_adb_none)
+		return -ENODEV;
+
+	return 0;
+}