1 files changed, 67 insertions, 0 deletions
diff --git a/arch/arm/boards/gateworks-ventana/gsc.c b/arch/arm/boards/gateworks-ventana/gsc.c
new file mode 100644
index 0000000000..3614230482
--- /dev/null
+++ b/arch/arm/boards/gateworks-ventana/gsc.c
@@ -0,0 +1,67 @@
+/*
+ * Copyright (C) 2013 Gateworks Corporation
+ * Copyright (C) 2014 Lucas Stach, Pengutronix
+ * Author: Tim Harvey <tharvey@gateworks.com>
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+/*
+ * The Gateworks System Controller will fail to ACK a master transaction if
+ * it is busy, which can occur during its 1HZ timer tick while reading ADC's.
+ * When this does occur, it will never be busy long enough to fail more than
+ * 2 back-to-back transfers.  Thus we wrap i2c_read and i2c_write with
+ * 3 retries.
+ */
+
+#include <common.h>
+#include <i2c/i2c.h>
+
+#include "gsc.h"
+
+int gsc_i2c_read(struct i2c_client *client, u32 addr, u8 *buf, u16 count)
+{
+	int retry = 3;
+	int n = 0;
+	int ret;
+
+	while (n++ < retry) {
+		ret = i2c_read_reg(client, addr,  buf, count);
+		if (!ret)
+			break;
+		pr_debug("GSC read failed\n");
+		if (ret != -ENODEV)
+			break;
+		mdelay(10);
+	}
+
+	return ret;
+}
+
+int gsc_i2c_write(struct i2c_client *client, u32 addr, const u8 *buf, u16 count)
+{
+	int retry = 3;
+	int n = 0;
+	int ret;
+
+	while (n++ < retry) {
+		ret = i2c_write_reg(client, addr, buf, count);
+		if (!ret)
+			break;
+		pr_debug("GSC write failed\n");
+		if (ret != -ENODEV)
+			break;
+		mdelay(10);
+	}
+	mdelay(100);
+
+	return ret;
+}