[PATCH] regmap: provide regmap_assign_bits()

[PATCH] regmap: provide regmap_assign_bits()

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

Add another bits helper to regmap API: this one sets given bits if value
is true and clears them if it's false.

Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
Hi Mark,

I'm sending this patch without any user yet but we have a use-case over in
the GPIO subsystem where this will come in handy soon.

Bartosz

 include/linux/regmap.h | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/include/linux/regmap.h b/include/linux/regmap.h
index e7834d98207f..62099e7a3ed6 100644
--- a/include/linux/regmap.h
+++ b/include/linux/regmap.h
@@ -1148,6 +1148,15 @@ static inline int regmap_clear_bits(struct regmap *map,
 	return regmap_update_bits_base(map, reg, bits, 0, NULL, false, false);
 }
 
+static inline int regmap_assign_bits(struct regmap *map, unsigned int reg,
+				     unsigned int bits, bool value)
+{
+	if (value)
+		return regmap_set_bits(map, reg, bits);
+	else
+		return regmap_clear_bits(map, reg, bits);
+}
+
 int regmap_test_bits(struct regmap *map, unsigned int reg, unsigned int bits);
 
 /**
@@ -1554,6 +1563,13 @@ static inline int regmap_clear_bits(struct regmap *map,
 	return -EINVAL;
 }
 
+static inline int regmap_assign_bits(struct regmap *map, unsigned int reg,
+				     unsigned int bits, bool value)
+{
+	WARN_ONCE(1, "regmap API is disabled");
+	return -EINVAL;
+}
+
 static inline int regmap_test_bits(struct regmap *map,
 				   unsigned int reg, unsigned int bits)
 {
-- 
2.29.1

Re: [PATCH] regmap: provide regmap_assign_bits()

[Mark Brown]

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On Mon, Oct 26, 2020 at 04:10:15PM +0100, Bartosz Golaszewski wrote:
> From: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> 
> Add another bits helper to regmap API: this one sets given bits if value
> is true and clears them if it's false.

What's the use case?

> +static inline int regmap_assign_bits(struct regmap *map, unsigned int reg,
> +				     unsigned int bits, bool value)

I don't have a great suggestion but this naming feels prone to confusion
with _update_bits().  

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Re: [PATCH] regmap: provide regmap_assign_bits()

[Bartosz Golaszewski]

On Thu, Oct 29, 2020 at 4:18 PM Mark Brown <broonie@kernel.org> wrote:
>
> On Mon, Oct 26, 2020 at 04:10:15PM +0100, Bartosz Golaszewski wrote:
> > From: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> >
> > Add another bits helper to regmap API: this one sets given bits if value
> > is true and clears them if it's false.
>
> What's the use case?
>

Basically what the function does: set bits if a condition is true,
clear them if false. I think this is a common enough use-case to
warrant a helper.

> > +static inline int regmap_assign_bits(struct regmap *map, unsigned int reg,
> > +                                  unsigned int bits, bool value)
>
> I don't have a great suggestion but this naming feels prone to confusion
> with _update_bits().

This is already used in bitops - we have set_bit(), clear_bit() and
assign_bit(). People are used to it and I thought I'd stay consistent
with this naming.

Bartosz

Re: [PATCH] regmap: provide regmap_assign_bits()

[Mark Brown]

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On Thu, Oct 29, 2020 at 04:44:16PM +0100, Bartosz Golaszewski wrote:
> On Thu, Oct 29, 2020 at 4:18 PM Mark Brown <broonie@kernel.org> wrote:
> > On Mon, Oct 26, 2020 at 04:10:15PM +0100, Bartosz Golaszewski wrote:

> > > Add another bits helper to regmap API: this one sets given bits if value
> > > is true and clears them if it's false.

> > What's the use case?

> Basically what the function does: set bits if a condition is true,
> clear them if false. I think this is a common enough use-case to
> warrant a helper.

I can tell what the function does, I can't tell why you'd want it and
simply stating that it's common isn't helping me here :(

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Re: [PATCH] regmap: provide regmap_assign_bits()

[Bartosz Golaszewski]

On Thu, Oct 29, 2020 at 4:48 PM Mark Brown <broonie@kernel.org> wrote:
>
> On Thu, Oct 29, 2020 at 04:44:16PM +0100, Bartosz Golaszewski wrote:
> > On Thu, Oct 29, 2020 at 4:18 PM Mark Brown <broonie@kernel.org> wrote:
> > > On Mon, Oct 26, 2020 at 04:10:15PM +0100, Bartosz Golaszewski wrote:
>
> > > > Add another bits helper to regmap API: this one sets given bits if value
> > > > is true and clears them if it's false.
>
> > > What's the use case?
>
> > Basically what the function does: set bits if a condition is true,
> > clear them if false. I think this is a common enough use-case to
> > warrant a helper.
>
> I can tell what the function does, I can't tell why you'd want it and
> simply stating that it's common isn't helping me here :(

Got it, I'll resend this together with the patches that need it then.

Bartosz