Re: [PATCH v2 1/2] gpio: add GPO driver for PCA9570

From: Sungbo Eo
Date: Tue Jun 30 2020 - 12:11:29 EST


Thanks for all the reviews! I've updated the patch, please have a look.

And I have something to ask.

# echo 1 > gpio408/value
# cat gpio408/value
cat: read error: I/O error
# cat gpio408/direction
out
# echo out > gpio408/direction
# echo in > gpio408/direction
[ 91.006691] gpio-408 (sysfs): gpiod_direction_input: missing get() but have direction_input()
ash: write error: I/O error

I've never dealt with GPO expander before, so this seems a bit odd to me.
Is it perfectly okay to leave get() and direction_input() unimplemented?

Thanks.

On 2020-06-30 18:53, Andy Shevchenko wrote:
On Tue, Jun 30, 2020 at 12:28 PM Bartosz Golaszewski
<bgolaszewski@xxxxxxxxxxxx> wrote:
On Thu, Jun 25, 2020 at 9:58 AM Sungbo Eo <mans0n@xxxxxxxxxx> wrote:

+static const struct of_device_id pca9570_of_match_table[] = {
+ { .compatible = "nxp,pca9570" },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, pca9570_of_match_table);

If you're not using it in probe than maybe move it next to the I2C device table?

(Side note)
...and even if so it can be assessed via a struct device pointer:
dev->driver->id_table (don't remember by heart, but you have an idea).