RE: [PATCH 1/2] ASoC: fsl_xcvr: Add XCVR ASoC CPU DAI driver

From: Viorel Suman (OSS)
Date: Fri Sep 18 2020 - 10:21:40 EST


Hi Nicolin,

Thank you for your review.

> > +static const u32 fsl_xcvr_earc_channels[] = { 1, 2, 8, 16, 32, }; /*
> > +one bit 6, 12 ? */
>
> What's the meaning of the comments?

Just a thought noted as comment. HDMI2.1 spec defines 6- and 12-channels layout when
one bit audio stream is transmitted - I was wandering how can this be enforced. Is a @todo like of comment.

>
> > +static const int fsl_xcvr_phy_arc_cfg[] = {
> > + FSL_XCVR_PHY_CTRL_ARC_MODE_SE_EN,
> FSL_XCVR_PHY_CTRL_ARC_MODE_CM_EN,
> > +};
>
> Nit: better be u32 vs. int?

Yes, will fix it in v2.

>
> > +/** phy: true => phy, false => pll */ static int
> > +fsl_xcvr_ai_write(struct fsl_xcvr *xcvr, u8 reg, u32 data, bool phy)
> > +{
> > + u32 val, idx, tidx;
> > +
> > + idx = BIT(phy ? 26 : 24);
> > + tidx = BIT(phy ? 27 : 25);
> > +
> > + regmap_write(xcvr->regmap, FSL_XCVR_PHY_AI_CTRL_CLR, 0xFF);
> > + regmap_write(xcvr->regmap, FSL_XCVR_PHY_AI_CTRL_SET, reg);
> > + regmap_write(xcvr->regmap, FSL_XCVR_PHY_AI_WDATA, data);
> > + regmap_write(xcvr->regmap, FSL_XCVR_PHY_AI_CTRL_TOG, idx);
> > +
> > + do {
> > + regmap_read(xcvr->regmap, FSL_XCVR_PHY_AI_CTRL, &val);
> > + } while ((val & idx) != ((val & tidx) >> 1));
>
> Might regmap_read_poll_timeout() be better? And it seems to poll intentionally
> with no sleep nor timeout -- would be nice to have a line of comments to explain
> why.

No particular reason to do it with no sleep or timeout here, will check and fix it in v2.

>
> > > +static int fsl_xcvr_runtime_resume(struct device *dev)
> > +{
> > + struct fsl_xcvr *xcvr = dev_get_drvdata(dev);
> > + int ret;
> > +
> > + ret = clk_prepare_enable(xcvr->ipg_clk);
> > + if (ret) {
> > + dev_err(dev, "failed to start IPG clock.\n");
> > + return ret;
> > + }
> > +
> > + ret = clk_prepare_enable(xcvr->pll_ipg_clk);
> > + if (ret) {
> > + dev_err(dev, "failed to start PLL IPG clock.\n");
>
> Should it disable ipg_clk?

Yes, thank you, will fix in v2.

>
> > + return ret;
> > + }
> > +
> > + ret = clk_prepare_enable(xcvr->phy_clk);
> > + if (ret) {
> > + dev_err(dev, "failed to start PHY clock: %d\n", ret);
> > + clk_disable_unprepare(xcvr->ipg_clk);
>
> Should it disable pll_ipg_clk?

Yes, will fix in v2.

>
> > + return ret;
> > + }
> > +
> > + ret = clk_prepare_enable(xcvr->spba_clk);
> > + if (ret) {
> > + dev_err(dev, "failed to start SPBA clock.\n");
> > + clk_disable_unprepare(xcvr->phy_clk);
> > + clk_disable_unprepare(xcvr->ipg_clk);
>
> Ditto

Ok.

>
> > + return ret;
> > + }
> > +
> > + regcache_cache_only(xcvr->regmap, false);
> > + regcache_mark_dirty(xcvr->regmap);
> > + ret = regcache_sync(xcvr->regmap);
> > +
> > + if (ret) {
> > + dev_err(dev, "failed to sync regcache.\n");
> > + return ret;
>
> What about those clocks? Probably better to have some error-out labels at the
> end of the function?

Make sense, will fix in v2.

>
> > + }
> > +
> > + reset_control_assert(xcvr->reset);
> > + reset_control_deassert(xcvr->reset);
> > +
> > + ret = fsl_xcvr_load_firmware(xcvr);
> > + if (ret) {
> > + dev_err(dev, "failed to load firmware.\n");
> > + return ret;
>
> Ditto
>
> > + }
> > +
> > + /* Release M0+ reset */
> > + ret = regmap_update_bits(xcvr->regmap, FSL_XCVR_EXT_CTRL,
> > + FSL_XCVR_EXT_CTRL_CORE_RESET, 0);
> > + if (ret < 0) {
> > + dev_err(dev, "M0+ core release failed: %d\n", ret);
> > + return ret;
>
> Ditto
>
> > + }
> > + mdelay(50);
>
> Any reason to use mdelay over msleep for a 50ms wait? May add a line of
> comments if mdelay is a must?

No particular reason, will fix it in v2.

Thank you,
Viorel