add single-wire serial bus interface (SSBI) driver

SSBI is the Qualcomm single-wire serial bus interface used to connect
the MSM devices to the PMIC and other devices.

Since SSBI only supports a single slave, the driver gets the name of the
slave device passed in from the board file through the master device's
platform data.

SSBI registers pretty early (postcore), so that the PMIC can come up
before the board init. This is useful if the board init requires the
use of gpios that are connected through the PMIC.

Based on a patch by Dima Zavin <dima@android.com> that can be found at:
http://android.git.kernel.org/?p=kernel/msm.git;a=commitdiff;h=eb060bac4

This patch adds PMIC Arbiter support for the MSM8660. The PMIC Arbiter
is a hardware wrapper around the SSBI 2.0 controller that is designed to
overcome concurrency issues and security limitations.  A controller_type
field is added to the platform data to specify the type of the SSBI
controller (1.0, 2.0, or PMIC Arbiter).

[davidb@codeaurora.org:
 I've moved this driver into drivers/ssbi/ and added an include for
 linux/module.h so that it will compile]

Signed-off-by: Kenneth Heitke <kheitke@codeaurora.org>
Signed-off-by: David Brown <davidb@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 49 insertions, 0 deletions

diff --git a/include/linux/msm_ssbi.h b/include/linux/msm_ssbi.h
new file mode 100644
index 000000000000..cfa47df6d003
--- /dev/null
+++ b/include/linux/msm_ssbi.h
@@ -0,0 +1,49 @@
+/* Copyright (C) 2010 Google, Inc.
+ * Copyright (c) 2011, Code Aurora Forum. All rights reserved.
+ * Author: Dima Zavin <dima@android.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * 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.
+ */
+
+#ifndef _LINUX_MSM_SSBI_H
+#define _LINUX_MSM_SSBI_H
+
+#include <linux/types.h>
+
+struct msm_ssbi_slave_info {
+	const char	*name;
+	void		*platform_data;
+};
+
+enum msm_ssbi_controller_type {
+	MSM_SBI_CTRL_SSBI = 0,
+	MSM_SBI_CTRL_SSBI2,
+	MSM_SBI_CTRL_PMIC_ARBITER,
+};
+
+struct msm_ssbi_platform_data {
+	struct msm_ssbi_slave_info	slave;
+	enum msm_ssbi_controller_type controller_type;
+};
+
+#ifdef CONFIG_MSM_SSBI
+int msm_ssbi_write(struct device *dev, u16 addr, u8 *buf, int len);
+int msm_ssbi_read(struct device *dev, u16 addr, u8 *buf, int len);
+#else
+static inline int msm_ssbi_write(struct device *dev, u16 addr, u8 *buf, int len)
+{
+	return -ENXIO;
+}
+static inline int msm_ssbi_read(struct device *dev, u16 addr, u8 *buf, int len)
+{
+	return -ENXIO;
+}
+#endif
+#endif