0025-CHROMIUM-Input-atmel_mxt_ts-dump-mxt_read-write_reg.patch

From e3ec445543f4fc6a603d3b7990763ef0641077ee Mon Sep 17 00:00:00 2001
From: Daniel Kurtz <djkurtz@chromium.org>
Date: Wed, 15 Feb 2012 16:32:02 +0800
Subject: [PATCH 25/57] CHROMIUM: Input: atmel_mxt_ts - dump mxt_read/write_reg

For verbose on-the-wire debugging.
Prints DUMP_LEN bytes (in hex) per line.

Signed-off-by: Daniel Kurtz <djkurtz@chromium.org>

BUG=chromium-os:27713
TEST=builds clean w/ & w/out DEBUG defined.
  If DEBUG defined, bytes read & written over i2c by atmel_mxt_ts should
  appear in /var/log/messages

Change-Id: Ib1b8301a25bb915fea47e4dd62ff261ae5284c3c
Reviewed-on: https://gerrit.chromium.org/gerrit/17943
Commit-Ready: Daniel Kurtz <djkurtz@chromium.org>
Reviewed-by: Daniel Kurtz <djkurtz@chromium.org>
Tested-by: Daniel Kurtz <djkurtz@chromium.org>

v3.7 rebase:
Signed-off-by: Daniel Kurtz <djkurtz@chromium.org>
---
 drivers/input/touchscreen/atmel_mxt_ts.c | 35 +++++++++++++++++++++++++++++++-
 1 file changed, 34 insertions(+), 1 deletion(-)

diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
index 2f22ae1..50fe84a 100644
--- a/drivers/input/touchscreen/atmel_mxt_ts.c
+++ b/drivers/input/touchscreen/atmel_mxt_ts.c
@@ -546,11 +546,39 @@ static int mxt_fw_write(struct i2c_client *client,
 	return mxt_i2c_send(client, data, frame_size);
 }
 
+#ifdef DEBUG
+#define DUMP_LEN	16
+static void mxt_dump_xfer(struct device *dev, const char *func, u16 reg,
+			  u16 len, const u8 *val)
+{
+	/* Rough guess for string size */
+	char str[DUMP_LEN * 3 + 2];
+	int i;
+	size_t n;
+
+	for (i = 0, n = 0; i < len; i++) {
+		n += snprintf(&str[n], sizeof(str) - n, "%02x ", val[i]);
+		if ((i + 1) % DUMP_LEN == 0 || (i + 1) == len) {
+			dev_dbg(dev,
+				"%s(reg: %d len: %d offset: 0x%02x): %s\n",
+				func, reg, len, (i / DUMP_LEN) * DUMP_LEN,
+				str);
+			n = 0;
+		}
+	}
+}
+#undef DUMP_LEN
+#else
+static void mxt_dump_xfer(struct device *dev, const char *func, u16 reg,
+			  u16 len, const u8 *val) { }
+#endif
+
 static int __mxt_read_reg(struct i2c_client *client,
 			       u16 reg, u16 len, void *val)
 {
 	struct i2c_msg xfer[2];
 	u8 buf[2];
+	int ret;
 
 	buf[0] = reg & 0xff;
 	buf[1] = (reg >> 8) & 0xff;
@@ -567,7 +595,11 @@ static int __mxt_read_reg(struct i2c_client *client,
 	xfer[1].len = len;
 	xfer[1].buf = val;
 
-	return mxt_i2c_transfer(client, xfer, 2);
+	ret = mxt_i2c_transfer(client, xfer, 2);
+	if (ret == 0)
+		mxt_dump_xfer(&client->dev, __func__, reg, len, val);
+
+	return ret;
 }
 
 static int mxt_read_reg(struct i2c_client *client, u16 reg, u8 *val)
@@ -591,6 +623,7 @@ static int __mxt_write_reg(struct i2c_client *client, u16 reg, u16 len,
 	buf[1] = (reg >> 8) & 0xff;
 	memcpy(&buf[2], val, len);
 
+	mxt_dump_xfer(&client->dev, __func__, reg, len, val);
 	ret = mxt_i2c_send(client, buf, count);
 	kfree(buf);
 	return ret;
-- 
1.8.2.1