[alsa-devel] [PATCH 2/2] ASoC: add driver for Rockchip RK3xxx I2S controller

[Huang Tao]

Hi, Mark:

于 2014年07月02日 01:07, Mark Brown 写道:
>> +static inline void i2s_writel(struct rk_i2s_dev *i2s, u32 value,
>> > +			      unsigned int offset)
>> > +{
>> > +	writel_relaxed(value, i2s->regs + offset);
>> > +}
>> > +
>> > +static inline u32 i2s_readl(struct rk_i2s_dev *i2s, unsigned int offset)
>> > +{
>> > +	return readl_relaxed(i2s->regs + offset);
>> > +}
> Perhaps use regmap?  The main advantage would be the debug
> infrastructure, though you could also use _update_bits() to reduce the
> amount of time spent locked.
>
Are you sure? This is a I2S driver, we can write the register directly,
do not through I2C or SPI bus.
Write a register is only a few instructions on ARM, but write through
regmap, it may take a long path.
I think it will just consume CPU power and make the whole thing more
complex.
Could you tell me what benefits we can get if use regmap? Or something I
just missing?