Re: [PATCH v3 1/2] power: supply: ltc2941-battery-gauge: Add OF device ID table

From: Sebastian Reichel
Date: Wed Mar 15 2017 - 17:01:28 EST


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/.

> 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.

-- 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
>

Attachment: signature.asc
Description: PGP signature