On Wed, Jul 02, 2014 at 09:01:49AM +0800, Huang Tao wrote:
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?
The main thing is the diagnostic infrastructure, plus the cache if you find you need that for suspend and resume (which you didn't implement yet) - that's the main reason things use regmap for memory mapped registers. There is some overhead but it's not *that* big.