| Message ID | 547F3CA5.2010500@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, Dec 03, 2014 at 04:39:01PM +0000, Andrew Jackson wrote: > + /* Iterate over set of channels - independently controlled. > + */ > + do { > + if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) { > + i2s_write_reg(dev->i2s_base, TCR(ch_reg), > + xfer_resolution); > + i2s_write_reg(dev->i2s_base, TFCR(ch_reg), 0x02); > + irq = i2s_read_reg(dev->i2s_base, IMR(ch_reg)); > + i2s_write_reg(dev->i2s_base, IMR(ch_reg), irq & ~0x30); > + i2s_write_reg(dev->i2s_base, TER(ch_reg), 1); > + } else { > + i2s_write_reg(dev->i2s_base, RCR(ch_reg), > + xfer_resolution); > + i2s_write_reg(dev->i2s_base, RFCR(ch_reg), 0x07); > + irq = i2s_read_reg(dev->i2s_base, IMR(ch_reg)); > + i2s_write_reg(dev->i2s_base, IMR(ch_reg), irq & ~0x03); > + i2s_write_reg(dev->i2s_base, RER(ch_reg), 1); > + } > + } while (ch_reg-- > 0); The normal way to write an iteration would be with a for loop - why are we not doing that? Also I see that you've not sent these as a single thread - please use --thread.
On Wed, Dec 3, 2014 at 10:59 PM, Mark Brown <broonie@kernel.org> wrote: > On Wed, Dec 03, 2014 at 04:39:01PM +0000, Andrew Jackson wrote: > >> + /* Iterate over set of channels - independently controlled. >> + */ >> + do { >> + if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) { >> + i2s_write_reg(dev->i2s_base, TCR(ch_reg), >> + xfer_resolution); >> + i2s_write_reg(dev->i2s_base, TFCR(ch_reg), 0x02); >> + irq = i2s_read_reg(dev->i2s_base, IMR(ch_reg)); >> + i2s_write_reg(dev->i2s_base, IMR(ch_reg), irq & ~0x30); >> + i2s_write_reg(dev->i2s_base, TER(ch_reg), 1); >> + } else { >> + i2s_write_reg(dev->i2s_base, RCR(ch_reg), >> + xfer_resolution); >> + i2s_write_reg(dev->i2s_base, RFCR(ch_reg), 0x07); >> + irq = i2s_read_reg(dev->i2s_base, IMR(ch_reg)); >> + i2s_write_reg(dev->i2s_base, IMR(ch_reg), irq & ~0x03); >> + i2s_write_reg(dev->i2s_base, RER(ch_reg), 1); >> + } >> + } while (ch_reg-- > 0); > > The normal way to write an iteration would be with a for loop - why are > we not doing that? > > Also I see that you've not sent these as a single thread - please use > --thread. designware i2s has individual register for channel support. It is like TCR(0), TCR(1) and so on.. So a macro is defined to capture these please check below #define #define TCR(x) (0x40 * x + 0x034) and the same is true for capture also. So there is no need for iteration. Only writing to the particular register will do the work. ~Rajeev
On 12/03/14 17:29, Mark Brown wrote: > On Wed, Dec 03, 2014 at 04:39:01PM +0000, Andrew Jackson wrote: > >> + /* Iterate over set of channels - independently controlled. >> + */ >> + do { >> + if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) { >> + i2s_write_reg(dev->i2s_base, TCR(ch_reg), >> + xfer_resolution); >> + i2s_write_reg(dev->i2s_base, TFCR(ch_reg), 0x02); >> + irq = i2s_read_reg(dev->i2s_base, IMR(ch_reg)); >> + i2s_write_reg(dev->i2s_base, IMR(ch_reg), irq & ~0x30); >> + i2s_write_reg(dev->i2s_base, TER(ch_reg), 1); >> + } else { >> + i2s_write_reg(dev->i2s_base, RCR(ch_reg), >> + xfer_resolution); >> + i2s_write_reg(dev->i2s_base, RFCR(ch_reg), 0x07); >> + irq = i2s_read_reg(dev->i2s_base, IMR(ch_reg)); >> + i2s_write_reg(dev->i2s_base, IMR(ch_reg), irq & ~0x03); >> + i2s_write_reg(dev->i2s_base, RER(ch_reg), 1); >> + } >> + } while (ch_reg-- > 0); > > The normal way to write an iteration would be with a for loop - why are > we not doing that? The intention was to minimise the changes, excluding whitespace, between this version and the original. Also, it is a perfectly valid looping construct. I'm happy to rework it into a for loop. > Also I see that you've not sent these as a single thread - please use > --thread. > Andrew
On 12/04/14 06:55, rajeev kumar wrote: > On Wed, Dec 3, 2014 at 10:59 PM, Mark Brown <broonie@kernel.org> wrote: >> On Wed, Dec 03, 2014 at 04:39:01PM +0000, Andrew Jackson wrote: >> >>> + /* Iterate over set of channels - independently controlled. >>> + */ >>> + do { >>> + if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) { >>> + i2s_write_reg(dev->i2s_base, TCR(ch_reg), >>> + xfer_resolution); >>> + i2s_write_reg(dev->i2s_base, TFCR(ch_reg), 0x02); >>> + irq = i2s_read_reg(dev->i2s_base, IMR(ch_reg)); >>> + i2s_write_reg(dev->i2s_base, IMR(ch_reg), irq & ~0x30); >>> + i2s_write_reg(dev->i2s_base, TER(ch_reg), 1); >>> + } else { >>> + i2s_write_reg(dev->i2s_base, RCR(ch_reg), >>> + xfer_resolution); >>> + i2s_write_reg(dev->i2s_base, RFCR(ch_reg), 0x07); >>> + irq = i2s_read_reg(dev->i2s_base, IMR(ch_reg)); >>> + i2s_write_reg(dev->i2s_base, IMR(ch_reg), irq & ~0x03); >>> + i2s_write_reg(dev->i2s_base, RER(ch_reg), 1); >>> + } >>> + } while (ch_reg-- > 0); >> >> The normal way to write an iteration would be with a for loop - why are >> we not doing that? >> >> Also I see that you've not sent these as a single thread - please use >> --thread. > > designware i2s has individual register for channel support. It is like > TCR(0), TCR(1) and so on.. So a macro is defined to capture these > please check below #define > > #define TCR(x) (0x40 * x + 0x034) > > and the same is true for capture also. So there is no need for > iteration. Only writing to the particular register will do the work. However params_channels returns the number of channels that the device needs to configure. So, for example, when there are four channels two sets of channel registers need to be programmed. Andrew > > ~Rajeev >
diff --git a/sound/soc/dwc/designware_i2s.c b/sound/soc/dwc/designware_i2s.c index f8946bd..c497ada 100644 --- a/sound/soc/dwc/designware_i2s.c +++ b/sound/soc/dwc/designware_i2s.c @@ -227,19 +227,25 @@ static int dw_i2s_hw_params(struct snd_pcm_substream *substream, i2s_disable_channels(dev, substream->stream); - if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) { - i2s_write_reg(dev->i2s_base, TCR(ch_reg), xfer_resolution); - i2s_write_reg(dev->i2s_base, TFCR(ch_reg), 0x02); - irq = i2s_read_reg(dev->i2s_base, IMR(ch_reg)); - i2s_write_reg(dev->i2s_base, IMR(ch_reg), irq & ~0x30); - i2s_write_reg(dev->i2s_base, TER(ch_reg), 1); - } else { - i2s_write_reg(dev->i2s_base, RCR(ch_reg), xfer_resolution); - i2s_write_reg(dev->i2s_base, RFCR(ch_reg), 0x07); - irq = i2s_read_reg(dev->i2s_base, IMR(ch_reg)); - i2s_write_reg(dev->i2s_base, IMR(ch_reg), irq & ~0x03); - i2s_write_reg(dev->i2s_base, RER(ch_reg), 1); - } + /* Iterate over set of channels - independently controlled. + */ + do { + if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) { + i2s_write_reg(dev->i2s_base, TCR(ch_reg), + xfer_resolution); + i2s_write_reg(dev->i2s_base, TFCR(ch_reg), 0x02); + irq = i2s_read_reg(dev->i2s_base, IMR(ch_reg)); + i2s_write_reg(dev->i2s_base, IMR(ch_reg), irq & ~0x30); + i2s_write_reg(dev->i2s_base, TER(ch_reg), 1); + } else { + i2s_write_reg(dev->i2s_base, RCR(ch_reg), + xfer_resolution); + i2s_write_reg(dev->i2s_base, RFCR(ch_reg), 0x07); + irq = i2s_read_reg(dev->i2s_base, IMR(ch_reg)); + i2s_write_reg(dev->i2s_base, IMR(ch_reg), irq & ~0x03); + i2s_write_reg(dev->i2s_base, RER(ch_reg), 1); + } + } while (ch_reg-- > 0); i2s_write_reg(dev->i2s_base, CCR, ccr);
On the Designware core, the channels are independent and not combined in higher registers. So as more channels are added, more registers need to be updated. Signed-off-by: Andrew Jackson <Andrew.Jackson@arm.com> --- sound/soc/dwc/designware_i2s.c | 32 +++++++++++++++++++------------- 1 files changed, 19 insertions(+), 13 deletions(-)