diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-stub.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-stub.c | 143 |
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); + |