On 19/10/15 18:47, Mark Brown wrote:
On Mon, Oct 12, 2015 at 01:40:29PM +0100, Damien Horsley wrote:
+static inline u32 img_i2s_in_ch_disable(struct img_i2s_in *i2s, u32 chan) +{
- u32 reg;
- reg = img_i2s_in_ch_readl(i2s, chan, IMG_I2S_IN_CH_CTL);
- reg &= ~IMG_I2S_IN_CH_CTL_ME_MASK;
- img_i2s_in_ch_writel(i2s, chan, reg, IMG_I2S_IN_CH_CTL);
- return reg;
+}
+static inline void img_i2s_in_ch_enable(struct img_i2s_in *i2s, u32 chan,
u32 reg)+{
- reg |= IMG_I2S_IN_CH_CTL_ME_MASK;
- img_i2s_in_ch_writel(i2s, chan, reg, IMG_I2S_IN_CH_CTL);
+}
The APIs here all seem a bit odd - for example the enable API taking a register value as an argument (normally reg is a register address BTW) and returning a value but the disable API doing a read/modify/write cycle.
Sure. It reduces the number of register accesses this way, but the difference in execution time is not significant. Would you prefer these to both do read-modify-writes?
+static inline void img_i2s_in_flush(struct img_i2s_in *i2s) +{
- int i;
- u32 reg;
- for (i = 0; i < i2s->active_channels; i++) {
reg = img_i2s_in_ch_disable(i2s, i);reg |= IMG_I2S_IN_CH_CTL_FIFO_FLUSH_MASK;img_i2s_in_ch_writel(i2s, i, reg, IMG_I2S_IN_CH_CTL);reg &= ~IMG_I2S_IN_CH_CTL_FIFO_FLUSH_MASK;img_i2s_in_ch_writel(i2s, i, reg, IMG_I2S_IN_CH_CTL);img_i2s_in_ch_enable(i2s, i, reg);- }
+}
This all seems to be connected to this, which is itself slightly funky especially in the context of the only user...
They are also used during hw_params and set_format.
- case SNDRV_PCM_TRIGGER_STOP:
- case SNDRV_PCM_TRIGGER_SUSPEND:
- case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
reg = img_i2s_in_readl(i2s, IMG_I2S_IN_CTL);reg &= ~IMG_I2S_IN_CTL_ME_MASK;img_i2s_in_writel(i2s, reg, IMG_I2S_IN_CTL);img_i2s_in_flush(i2s);break;...which looks like it'll enable everything, then disable and reenable. Plus needing to do a flush on trigger seems weird.
If the FIFOs are not flushed, some samples from the previous stream will be transferred to the user application when the block is started again
- if ((channels < 2) ||
(channels > (i2s->max_i2s_chan * 2)) ||(channels % 2))return -EINVAL;This indentation is very weird.
Ok. What is the correct indentation for this?
- control_mask = (u32)(~IMG_I2S_IN_CTL_16PACK_MASK &
~IMG_I2S_IN_CTL_ACTIVE_CHAN_MASK);
- chan_control_mask = (u32)(~IMG_I2S_IN_CH_CTL_16PACK_MASK &
~IMG_I2S_IN_CH_CTL_FEN_MASK &~IMG_I2S_IN_CH_CTL_FMODE_MASK &~IMG_I2S_IN_CH_CTL_SW_MASK &~IMG_I2S_IN_CH_CTL_FW_MASK &~IMG_I2S_IN_CH_CTL_PACKH_MASK);This also looks very odd. Normally we'd write masks as being the valid bits and or them together.
Ok
- i2s->clk_sys = devm_clk_get(dev, "sys");
- if (IS_ERR(i2s->clk_sys))
return PTR_ERR(i2s->clk_sys);Please print an error message so people can tell why things failed.
Ok
- rst = devm_reset_control_get(dev, "rst");
- if (IS_ERR(rst)) {
dev_dbg(dev, "No top level reset found\n");You should check for -EPROBE_DEFER here and just return the error here if you get it (on the basis that the reset framework ought to be using a different error if there's nothing bound in DT).
Ok