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.
> +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...
> + 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 ((channels < 2) ||
> + (channels > (i2s->max_i2s_chan * 2)) ||
> + (channels % 2))
> + return -EINVAL;
This indentation is very weird.
> + 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.
> + 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.
> + 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).
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