1 files changed, 143 insertions, 0 deletions

diff --git a/drivers/i2c/busses/i2c-stub.c b/drivers/i2c/busses/i2c-stub.c
new file mode 100644
index 000000000000..19c805ead4d8
--- /dev/null
+++ b/drivers/i2c/busses/i2c-stub.c
@@ -0,0 +1,143 @@
+/*
+    i2c-stub.c - Part of lm_sensors, Linux kernel modules for hardware
+              monitoring
+
+    Copyright (c) 2004 Mark M. Hoffman <mhoffman@lightlink.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.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+#define DEBUG 1
+
+#include <linux/config.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/i2c.h>
+
+static u8  stub_pointer;
+static u8  stub_bytes[256];
+static u16 stub_words[256];
+
+/* Return -1 on error. */
+static s32 stub_xfer(struct i2c_adapter * adap, u16 addr, unsigned short flags,
+        char read_write, u8 command, int size, union i2c_smbus_data * data)
+{
+        s32 ret;
+
+        switch (size) {
+
+        case I2C_SMBUS_QUICK:
+                dev_dbg(&adap->dev, "smbus quick - addr 0x%02x\n", addr);
+                ret = 0;
+                break;
+
+        case I2C_SMBUS_BYTE:
+                if (read_write == I2C_SMBUS_WRITE) {
+                        stub_pointer = command;
+                        dev_dbg(&adap->dev, "smbus byte - addr 0x%02x, "
+                                        "wrote 0x%02x.\n",
+                                        addr, command);
+                } else {
+                        data->byte = stub_bytes[stub_pointer++];
+                        dev_dbg(&adap->dev, "smbus byte - addr 0x%02x, "
+                                        "read  0x%02x.\n",
+                                        addr, data->byte);
+                }
+
+                ret = 0;
+                break;
+
+        case I2C_SMBUS_BYTE_DATA:
+                if (read_write == I2C_SMBUS_WRITE) {
+                        stub_bytes[command] = data->byte;
+                        dev_dbg(&adap->dev, "smbus byte data - addr 0x%02x, "
+                                        "wrote 0x%02x at 0x%02x.\n",
+                                        addr, data->byte, command);
+                } else {
+                        data->byte = stub_bytes[command];
+                        dev_dbg(&adap->dev, "smbus byte data - addr 0x%02x, "
+                                        "read  0x%02x at 0x%02x.\n",
+                                        addr, data->byte, command);
+                }
+                stub_pointer = command + 1;
+
+                ret = 0;
+                break;
+
+        case I2C_SMBUS_WORD_DATA:
+                if (read_write == I2C_SMBUS_WRITE) {
+                        stub_words[command] = data->word;
+                        dev_dbg(&adap->dev, "smbus word data - addr 0x%02x, "
+                                        "wrote 0x%04x at 0x%02x.\n",
+                                        addr, data->word, command);
+                } else {
+                        data->word = stub_words[command];
+                        dev_dbg(&adap->dev, "smbus word data - addr 0x%02x, "
+                                        "read  0x%04x at 0x%02x.\n",
+                                        addr, data->word, command);
+                }
+
+                ret = 0;
+                break;
+
+        default:
+                dev_dbg(&adap->dev, "Unsupported I2C/SMBus command\n");
+                ret = -1;
+                break;
+        } /* switch (size) */
+
+        return ret;
+}
+
+static u32 stub_func(struct i2c_adapter *adapter)
+{
+        return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
+                I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA;
+}
+
+static struct i2c_algorithm smbus_algorithm = {
+        .name           = "Non-I2C SMBus adapter",
+        .id             = I2C_ALGO_SMBUS,
+        .functionality  = stub_func,
+        .smbus_xfer     = stub_xfer,
+};
+
+static struct i2c_adapter stub_adapter = {
+        .owner          = THIS_MODULE,
+        .class          = I2C_CLASS_HWMON,
+        .algo           = &smbus_algorithm,
+        .name           = "SMBus stub driver",
+};
+
+static int __init i2c_stub_init(void)
+{
+        printk(KERN_INFO "i2c-stub loaded\n");
+        return i2c_add_adapter(&stub_adapter);
+}
+
+static void __exit i2c_stub_exit(void)
+{
+        i2c_del_adapter(&stub_adapter);
+}
+
+MODULE_AUTHOR("Mark M. Hoffman <mhoffman@lightlink.com>");
+MODULE_DESCRIPTION("I2C stub driver");
+MODULE_LICENSE("GPL");
+
+module_init(i2c_stub_init);
+module_exit(i2c_stub_exit);
+