ASoC: soc-component: add snd_soc_component_read/write_field()

It's often the case that we would write or read a particular field
in register. With the current soc_component apis, reading a particular
field in register would involve first read the register and then
perform shift operations.

Ex:
to read from a field mask of 0xf0

	val = snd_soc_component_read(component, reg);
	field = ((val & 0xf0) >> 0x4);

This is sometimes prone to errors and code become less readable!

With this new api we could just do
	field = snd_soc_component_read_field(component, reg, 0xf0);

this makes it bit simple, easy to write and less error prone!

This also applies to writing!

There are various places in kernel which provides such field interfaces
however soc_component seems to be missing this.

This patch is inspired by FIELD_GET/FIELD_PREP macros in include/linux/bitfield.h

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20210126171749.1863-1-srinivas.kandagatla@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Srinivas Kandagatla 2021-01-26 17:17:48 +00:00 committed by Mark Brown
parent ed9ce1ed22
commit 1da0b9899a
No known key found for this signature in database
GPG Key ID: 24D68B725D5487D0
2 changed files with 59 additions and 0 deletions

View File

@ -353,6 +353,12 @@ int snd_soc_component_test_bits(struct snd_soc_component *component,
unsigned int reg, unsigned int mask, unsigned int reg, unsigned int mask,
unsigned int value); unsigned int value);
unsigned int snd_soc_component_read_field(struct snd_soc_component *component,
unsigned int reg, unsigned int mask);
int snd_soc_component_write_field(struct snd_soc_component *component,
unsigned int reg, unsigned int mask,
unsigned int val);
/* component wide operations */ /* component wide operations */
int snd_soc_component_set_sysclk(struct snd_soc_component *component, int snd_soc_component_set_sysclk(struct snd_soc_component *component,
int clk_id, int source, int clk_id, int source,

View File

@ -34,6 +34,18 @@ static inline int _soc_component_ret(struct snd_soc_component *component,
return ret; return ret;
} }
static inline int soc_component_field_shift(struct snd_soc_component *component,
unsigned int mask)
{
if (!mask) {
dev_err(component->dev, "ASoC: error field mask is zero for %s\n",
component->name);
return 0;
}
return (__builtin_ffs(mask) - 1);
}
/* /*
* We might want to check substream by using list. * We might want to check substream by using list.
* In such case, we can update these macros. * In such case, we can update these macros.
@ -839,6 +851,47 @@ int snd_soc_component_update_bits_async(struct snd_soc_component *component,
} }
EXPORT_SYMBOL_GPL(snd_soc_component_update_bits_async); EXPORT_SYMBOL_GPL(snd_soc_component_update_bits_async);
/**
* snd_soc_component_read_field() - Read register field value
* @component: Component to read from
* @reg: Register to read
* @mask: mask of the register field
*
* Return: read value of register field.
*/
unsigned int snd_soc_component_read_field(struct snd_soc_component *component,
unsigned int reg, unsigned int mask)
{
unsigned int val;
val = snd_soc_component_read(component, reg);
val = (val & mask) >> soc_component_field_shift(component, mask);
return val;
}
EXPORT_SYMBOL_GPL(snd_soc_component_read_field);
/**
* snd_soc_component_write_field() - write to register field
* @component: Component to write to
* @reg: Register to write
* @mask: mask of the register field to update
* @val: value of the field to write
*
* Return: 1 for change, otherwise 0.
*/
int snd_soc_component_write_field(struct snd_soc_component *component,
unsigned int reg, unsigned int mask,
unsigned int val)
{
val = (val << soc_component_field_shift(component, mask)) & mask;
return snd_soc_component_update_bits(component, reg, mask, val);
}
EXPORT_SYMBOL_GPL(snd_soc_component_write_field);
/** /**
* snd_soc_component_async_complete() - Ensure asynchronous I/O has completed * snd_soc_component_async_complete() - Ensure asynchronous I/O has completed
* @component: Component for which to wait * @component: Component for which to wait