[PATCH v8 08/18] gpiolib: regmap: add write_data_after_dir quirk

[zl020895]

Hi Linus,

Thanks for the review.
I will do in the next revision.

Best regards,
Long Zhao

At 2026-09-22 15:17:48, "Linus Walleij" <linusw at kernel.org> wrote:
>Hi Long,
>
>this is starting to look good!
>
>On Mon, Sep 21, 2026 at 6:23 AM Long Zhao via B4 Relay
><devnull+longzhao.ambarella.com at kernel.org> wrote:
>
>> From: Long Zhao <longzhao at ambarella.com>
>>
>> Some controllers ignore data-register writes while a line is still an
>> input. Optionally write the output value again after switching the
>> direction, matching the existing PL061 behaviour.
>>
>> Signed-off-by: Long Zhao <longzhao at ambarella.com>
>(...)
>
>> +++ b/include/linux/gpio/regmap.h
>> @@ -48,6 +48,13 @@ struct regmap;
>>   *                     (Optional) Bitmap representing the fixed direction of
>>   *                     the GPIO lines. Useful when there are GPIO lines with a
>>   *                     fixed direction mixed together in the same register.
>> + * @write_data_after_dir:
>> + *                     (Optional) Write the output value again after
>> + *                     switching a line to output in ->direction_output().
>> + *                     Needed for hardware which ignores data register
>> + *                     writes while the line is configured as an input.
>> + *                     This is a legacy quirk (e.g. ARM PL061); new hardware
>> + *                     must not use it. Direction changes will glitch.
>>   * @drvdata:           (Optional) Pointer to driver specific data which is
>>   *                     not used by gpio-remap but is provided "as is" to the
>>   *                     driver callback(s).
>> @@ -94,6 +101,7 @@ struct gpio_regmap_config {
>>         unsigned int reg_dir_out_base;
>>         int reg_stride;
>>         int ngpio_per_reg;
>> +       bool write_data_after_dir;
>>         struct irq_domain *irq_domain;
>>         unsigned long *fixed_direction_mask;
>>         unsigned long *fixed_direction_output;
>
>1. You have put the kerneldoc in a completely different place in the order
>of thing than where you put the flag in the struct.
>
>2. Put a comment above the behaviour flags because there will
>invariably be more of them! Something like:
>/* Regmap GPIO behaviour flags */
>
>3. Put a newline before & after the flags so they end up in a separate
>section of the struct, so people know where to add them.
>
>I would put them:
>
>        struct device *parent;
>        struct regmap *regmap;
>        struct fwnode_handle *fwnode;
>
>        const char *label;
>        int ngpio;
>        const char *const *names;
>
>HERE
>
>        unsigned int reg_dat_base;
>        unsigned int reg_set_base;
>
>Yours,
>Linus Walleij