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path: root/drivers/i2c/busses/i2c-stub.c
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Diffstat (limited to 'drivers/i2c/busses/i2c-stub.c')
-rw-r--r--drivers/i2c/busses/i2c-stub.c19
1 files changed, 18 insertions, 1 deletions
diff --git a/drivers/i2c/busses/i2c-stub.c b/drivers/i2c/busses/i2c-stub.c
index 73f481e93a36..8cf374ddd989 100644
--- a/drivers/i2c/busses/i2c-stub.c
+++ b/drivers/i2c/busses/i2c-stub.c
@@ -27,6 +27,10 @@
#include <linux/errno.h>
#include <linux/i2c.h>
+static unsigned short chip_addr;
+module_param(chip_addr, ushort, S_IRUGO);
+MODULE_PARM_DESC(chip_addr, "Chip address (between 0x03 and 0x77)\n");
+
static u8 stub_pointer;
static u8 stub_bytes[256];
static u16 stub_words[256];
@@ -37,6 +41,9 @@ static s32 stub_xfer(struct i2c_adapter * adap, u16 addr, unsigned short flags,
{
s32 ret;
+ if (addr != chip_addr)
+ return -ENODEV;
+
switch (size) {
case I2C_SMBUS_QUICK:
@@ -122,7 +129,17 @@ static struct i2c_adapter stub_adapter = {
static int __init i2c_stub_init(void)
{
- printk(KERN_INFO "i2c-stub loaded\n");
+ if (!chip_addr) {
+ printk(KERN_ERR "i2c-stub: Please specify a chip address\n");
+ return -ENODEV;
+ }
+ if (chip_addr < 0x03 || chip_addr > 0x77) {
+ printk(KERN_ERR "i2c-stub: Invalid chip address 0x%02x\n",
+ chip_addr);
+ return -EINVAL;
+ }
+
+ printk(KERN_INFO "i2c-stub: Virtual chip at 0x%02x\n", chip_addr);
return i2c_add_adapter(&stub_adapter);
}