Hello Sebastian,
On 03/15/2017 05:55 PM, Sebastian Reichel wrote:
> Hi,
>
> On Wed, Mar 15, 2017 at 12:43:48AM -0300, Javier Martinez Canillas wrote:
>> The driver doesn't have a struct of_device_id table but supported devices
>> are registered via Device Trees. This is working on the assumption that a
>> I2C device registered via OF will always match a legacy I2C device ID and
>> that the MODALIAS reported will always be of the form i2c:<device>.
>
> I don't get hits for "grep -r ltc294[13]" in arch/.
>
There isn't a mainline DTS that use these but the compatible strings (without a
vendor prefix) are listed in the following DT binding document:
Documentation/devicetree/bindings/power/supply/ltc2941.txt.
>> But this could change in the future so the correct approach is to have an
>> OF device ID table if the devices are registered via OF.
>>
>> The compatible strings don't have a vendor prefix because that's how it's
>> used currently, and changing this will be a Device Tree ABI break.
>
> I think the DT strings should have a vendor prefix.
> So I will only queue this with an explicit Acked-By from Rob or Mark.
>
Yes, I agree with you. I don't know though what should happen with DT bindings
that mentions a compatible without a vendor prefix as the one for this driver.
> -- Sebastian
>
>> Changes in v3:
>> - Don't use of_match_ptr() to avoid build warning when CONFIG_OF is disabled.
>>
>> Changes in v2:
>> Fix build warning reported by kbuild test robot.
>> - Fix wrong compatible strings due a copy & paste error.
>>
>> drivers/power/supply/ltc2941-battery-gauge.c | 19 +++++++++++++++++--
>> 1 file changed, 17 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/power/supply/ltc2941-battery-gauge.c
>> b/drivers/power/supply/ltc2941-battery-gauge.c
>> index 4adf2ba021ce..d3052be1bead 100644
>> --- a/drivers/power/supply/ltc2941-battery-gauge.c
>> +++ b/drivers/power/supply/ltc2941-battery-gauge.c
>> @@ -9,6 +9,7 @@
>> */
>> #include <linux/kernel.h>
>> #include <linux/module.h>
>> +#include <linux/of_device.h>
>> #include <linux/types.h>
>> #include <linux/errno.h>
>> #include <linux/swab.h>
>> @@ -61,7 +62,7 @@ struct ltc294x_info {
>> struct power_supply *supply; /* Supply pointer */
>> struct power_supply_desc supply_desc; /* Supply description */
>> struct delayed_work work; /* Work scheduler */
>> - int num_regs; /* Number of registers (chip type) */
>> + unsigned long num_regs; /* Number of registers (chip type) */
>> int charge; /* Last charge register content */
>> int r_sense; /* mOhm */
>> int Qlsb; /* nAh */
>> @@ -387,7 +388,7 @@ static int ltc294x_i2c_probe(struct i2c_client *client,
>>
>> np = of_node_get(client->dev.of_node);
>>
>> - info->num_regs = id->driver_data;
>> + info->num_regs = (unsigned long)of_device_get_match_data(&client->dev);
>> info->supply_desc.name = np->name;
>>
>> /* r_sense can be negative, when sense+ is connected to the battery
>> @@ -497,9 +498,23 @@ static const struct i2c_device_id ltc294x_i2c_id[] = {
>> };
>> MODULE_DEVICE_TABLE(i2c, ltc294x_i2c_id);
>>
>> +static const struct of_device_id ltc294x_i2c_of_match[] = {
>> + {
>> + .compatible = "ltc2941",
>> + .data = (void *)LTC2941_NUM_REGS
>> + },
>> + {
>> + .compatible = "ltc2943",
>> + .data = (void *)LTC2943_NUM_REGS
>> + },
>> + { },
>> +};
>> +MODULE_DEVICE_TABLE(of, ltc294x_i2c_of_match);
>> +
>> static struct i2c_driver ltc294x_driver = {
>> .driver = {
>> .name = "LTC2941",
>> + .of_match_table = ltc294x_i2c_of_match,
>> .pm = LTC294X_PM_OPS,
>> },
>> .probe = ltc294x_i2c_probe,
>> --
>> 2.9.3
>>
Best regards,
--
Javier Martinez Canillas
Open Source Group
Samsung Research America
