@@ -240,7 +240,7 @@ static int i2c_device_probe(struct device *dev)
return 0;
driver = to_i2c_driver(dev->driver);
- if (!driver->probe || !driver->id_table)
+ if (!driver->probe || (!driver->id_table && !dev->driver->of_match_table))
return -ENODEV;
client->driver = driver;
if (!device_can_wakeup(&client->dev))
@@ -248,7 +248,12 @@ static int i2c_device_probe(struct device *dev)
client->flags & I2C_CLIENT_WAKE);
dev_dbg(dev, "probe\n");
- status = driver->probe(client, i2c_match_id(driver->id_table, client));
+ if (dev->driver->of_match_table)
+ /* Device tree matching */
+ status = driver->probe(client, NULL);
+ else
+ /* Fall back to matching the id_table */
+ status = driver->probe(client, i2c_match_id(driver->id_table, client));
if (status) {
client->driver = NULL;
i2c_set_clientdata(client, NULL);
This tries to address an issue found when writing an MFD driver for the Nomadik STw481x PMICs: as the platform is using device tree exclusively I want to specify the driver matching like this: static const struct of_device_id stw481x_match[] = { { .compatible = "st,stw4810", }, { .compatible = "st,stw4811", }, {}, }; static struct i2c_driver stw481x_driver = { .driver = { .name = "stw481x", .of_match_table = stw481x_match, }, .probe = stw481x_probe, .remove = stw481x_remove, }; However that turns out not to be possible: the I2C probe code is written so that the probe() call is always passed a match from i2c_match_id() using non-devicetree matches. This is probably why most devices using device tree for I2C clients currently will pass no .of_match_table *at all* but instead just use .id_table from struct i2c_driver to match the device. As you realize that means that the whole idea with compatible strings is discarded, and that is why we find strange device tree I2C device compatible strings like "product" instead of "vendor,product" as you could expect. Let's figure out how to fix this before the mess spreads. This patch will allow probeing devices with only an of_match_table as per above, and will pass NULL as the second argument to the probe() function. If the driver wants to deduce secondary info from the struct of_device_id .data field, it has to call of_match_device() on its own match table in the probe function device tree probe path. If drivers define both an .of_match_table *AND* a i2c_driver .id_table, the .of_match_table will take precedence, just as is done in the i2c_device_match() function in i2c-core.c. I2C devices probed from device tree should subsequently be fixed to handle the case where of_match_table() is used (I think none of them do that today), and platforms should fix their device trees to use compatible strings for I2C devices instead of setting the name to Linux device driver names as is done in multiple cases today. Cc: Rob Herring <rob.herring@calxeda.com> Cc: Grant Likely <grant.likely@linaro.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> --- I would need some device tree core people to confirm that I am on the right track with this. I was soooo confused when I found that .of_match_table could not be used with I2C devices... --- drivers/i2c/i2c-core.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)