by Piyush Malgujar

[permalink] [raw]

Subject: Re: [PATCH v3 2/6] mmc: sdhci-cadence: Restructure the code

Hi Adrian,

Thanks for the review comments.

On Fri, Mar 03, 2023 at 10:36:30AM +0200, Adrian Hunter wrote:
> On 27/02/23 20:31, Piyush Malgujar wrote:
> > From: Dhananjay Kangude <[email protected]>
> >
> > Restructured the code, added new structures and functions for
> > SD4 operations. Also this adds some abstraction to the code
> > which will make it modular and adaptable for further SD6 operations.
> >
> > Signed-off-by: Dhananjay Kangude <[email protected]>
> > Co-developed-by: Jayanthi Annadurai <[email protected]>
> > Signed-off-by: Jayanthi Annadurai <[email protected]>
> > Signed-off-by: Piyush Malgujar <[email protected]>
> > ---
> > drivers/mmc/host/sdhci-cadence.c | 100 ++++++++++++++++++++++++-------
> > 1 file changed, 80 insertions(+), 20 deletions(-)
> >
> > diff --git a/drivers/mmc/host/sdhci-cadence.c b/drivers/mmc/host/sdhci-cadence.c
> > index 5276cdbc652f7faac13bb0244af4926b63dc119a..4f7e63c90e3d68da338b8964f08b7c65ebaf1ffd 100644
> > --- a/drivers/mmc/host/sdhci-cadence.c
> > +++ b/drivers/mmc/host/sdhci-cadence.c
> > @@ -59,16 +59,28 @@
> > */
> > #define SDHCI_CDNS_MAX_TUNING_LOOP 40
> >
> > +struct sdhci_cdns_priv;
> > +
> > struct sdhci_cdns_sd4_phy_param {
> > u8 addr;
> > u8 data;
> > };
> >
> > +struct sdhci_cdns_data {
> > + int (*phy_init)(struct sdhci_cdns_priv *priv);
> > + int (*set_tune_val)(struct sdhci_host *host, unsigned int val);
> > +};
> > +
> > +struct sdhci_cdns_sd4_phy {
> > + unsigned int nr_phy_params;
> > + struct sdhci_cdns_sd4_phy_param phy_params[];
> > +};
> > +
> > struct sdhci_cdns_priv {
> > void __iomem *hrs_addr;
> > bool enhanced_strobe;
> > - unsigned int nr_phy_params;
> > - struct sdhci_cdns_sd4_phy_param phy_params[];
> > + const struct sdhci_cdns_data *cdns_data;
>
> Simpler if there is just a pointer to struct sdhci_cdns_of_data
> and get rid of struct sdhci_cdns_data.
>

Sure, will take care of this.

> > + void *phy;
> > };
> >
> > struct sdhci_cdns_sd4_phy_cfg {
> > @@ -76,6 +88,13 @@ struct sdhci_cdns_sd4_phy_cfg {
> > u8 addr;
> > };
> >
> > +struct sdhci_cdns_of_data {
> > + const struct sdhci_pltfm_data *pltfm_data;
>
> Kernel style is not to unnecessarily have structures that point to
> other structures or contain other structures.
>
> Here, please just put the struct not a pointer i.e.
>
> struct sdhci_pltfm_data *pltfm_data;
>

Ok, so, to use

struct sdhci_pltfm_data pltfm_data;

> > + const struct sdhci_cdns_data *cdns_data;
>
> Please get rid of struct sdhci_cdns_data. Instead just put its members here
>

Ok, will modify in next version.

> > + int (*phy_probe)(struct platform_device *pdev,
> > + struct sdhci_cdns_priv *priv);
> > +};
> > +
> > static const struct sdhci_cdns_sd4_phy_cfg sdhci_cdns_sd4_phy_cfgs[] = {
> > { "cdns,phy-input-delay-sd-highspeed", SDHCI_CDNS_PHY_DLY_SD_HS, },
> > { "cdns,phy-input-delay-legacy", SDHCI_CDNS_PHY_DLY_SD_DEFAULT, },
> > @@ -135,9 +154,9 @@ static unsigned int sdhci_cdns_sd4_phy_param_count(struct device_node *np)
> > }
> >
> > static void sdhci_cdns_sd4_phy_param_parse(struct device_node *np,
> > - struct sdhci_cdns_priv *priv)
> > + struct sdhci_cdns_sd4_phy *phy)
> > {
> > - struct sdhci_cdns_sd4_phy_param *p = priv->phy_params;
> > + struct sdhci_cdns_sd4_phy_param *p = phy->phy_params;
> > u32 val;
> > int ret, i;
> >
> > @@ -156,10 +175,11 @@ static void sdhci_cdns_sd4_phy_param_parse(struct device_node *np,
> > static int sdhci_cdns_sd4_phy_init(struct sdhci_cdns_priv *priv)
> > {
> > int ret, i;
> > + struct sdhci_cdns_sd4_phy *phy = priv->phy;
> >
> > - for (i = 0; i < priv->nr_phy_params; i++) {
> > - ret = sdhci_cdns_sd4_write_phy_reg(priv, priv->phy_params[i].addr,
> > - priv->phy_params[i].data);
> > + for (i = 0; i < phy->nr_phy_params; i++) {
> > + ret = sdhci_cdns_sd4_write_phy_reg(priv, phy->phy_params[i].addr,
> > + phy->phy_params[i].data);
> > if (ret)
> > return ret;
> > }
> > @@ -202,6 +222,27 @@ static u32 sdhci_cdns_get_emmc_mode(struct sdhci_cdns_priv *priv)
> > return FIELD_GET(SDHCI_CDNS_HRS06_MODE, tmp);
> > }
> >
> > +static int sdhci_cdns_sd4_phy_probe(struct platform_device *pdev,
> > + struct sdhci_cdns_priv *priv)
> > +{
> > + unsigned int nr_phy_params;
> > + struct sdhci_cdns_sd4_phy *phy;
> > + struct device *dev = &pdev->dev;
> > +
> > + nr_phy_params = sdhci_cdns_sd4_phy_param_count(dev->of_node);
> > + phy = devm_kzalloc(dev, struct_size(phy, phy_params, nr_phy_params),
> > + GFP_KERNEL);
> > + if (!phy)
> > + return -ENOMEM;
> > +
> > + phy->nr_phy_params = nr_phy_params;
> > +
> > + sdhci_cdns_sd4_phy_param_parse(dev->of_node, phy);
> > + priv->phy = phy;
> > +
> > + return 0;
> > +}
> > +
> > static int sdhci_cdns_sd4_set_tune_val(struct sdhci_host *host, unsigned int val)
> > {
> > struct sdhci_cdns_priv *priv = sdhci_cdns_priv(host);
> > @@ -323,10 +364,25 @@ static const struct sdhci_pltfm_data sdhci_cdns_uniphier_pltfm_data = {
> > .quirks2 = SDHCI_QUIRK2_PRESET_VALUE_BROKEN,
> > };
> >
> > +static const struct sdhci_cdns_of_data sdhci_cdns_uniphier_of_data = {
> > + .pltfm_data = &sdhci_cdns_uniphier_pltfm_data,
> > +};
> > +
> > static const struct sdhci_pltfm_data sdhci_cdns_sd4_pltfm_data = {
> > .ops = &sdhci_cdns_sd4_ops,
> > };
> >
> > +static const struct sdhci_cdns_data sdhci_cdns_sd4_data = {
> > + .phy_init = sdhci_cdns_sd4_phy_init,
> > + .set_tune_val = sdhci_cdns_sd4_set_tune_val,
> > +};
> > +
> > +static const struct sdhci_cdns_of_data sdhci_cdns_sd4_of_data = {
> > + .pltfm_data = &sdhci_cdns_sd4_pltfm_data,
> > + .cdns_data = &sdhci_cdns_sd4_data,
> > + .phy_probe = sdhci_cdns_sd4_phy_probe,
> > +};
> > +
> > static void sdhci_cdns_hs400_enhanced_strobe(struct mmc_host *mmc,
> > struct mmc_ios *ios)
> > {
> > @@ -350,11 +406,10 @@ static void sdhci_cdns_hs400_enhanced_strobe(struct mmc_host *mmc,
> > static int sdhci_cdns_probe(struct platform_device *pdev)
> > {
> > struct sdhci_host *host;
> > - const struct sdhci_pltfm_data *data;
> > + const struct sdhci_cdns_of_data *data;
> > struct sdhci_pltfm_host *pltfm_host;
> > struct sdhci_cdns_priv *priv;
> > struct clk *clk;
> > - unsigned int nr_phy_params;
> > int ret;
> > struct device *dev = &pdev->dev;
> > static const u16 version = SDHCI_SPEC_400 << SDHCI_SPEC_VER_SHIFT;
> > @@ -368,12 +423,12 @@ static int sdhci_cdns_probe(struct platform_device *pdev)
> > return ret;
> >
> > data = of_device_get_match_data(dev);
> > - if (!data)
> > - data = &sdhci_cdns_sd4_pltfm_data;
> > + if (!data) {
> > + ret = -EINVAL;
> > + goto disable_clk;
> > + }
> >
> > - nr_phy_params = sdhci_cdns_sd4_phy_param_count(dev->of_node);
> > - host = sdhci_pltfm_init(pdev, data,
> > - struct_size(priv, phy_params, nr_phy_params));
> > + host = sdhci_pltfm_init(pdev, data->pltfm_data, sizeof(*priv));
> > if (IS_ERR(host)) {
> > ret = PTR_ERR(host);
> > goto disable_clk;
> > @@ -383,9 +438,9 @@ static int sdhci_cdns_probe(struct platform_device *pdev)
> > pltfm_host->clk = clk;
> >
> > priv = sdhci_pltfm_priv(pltfm_host);
> > - priv->nr_phy_params = nr_phy_params;
> > priv->hrs_addr = host->ioaddr;
> > priv->enhanced_strobe = false;
> > + priv->cdns_data = data->cdns_data;
> > host->ioaddr += SDHCI_CDNS_SRS_BASE;
> > host->mmc_host_ops.hs400_enhanced_strobe =
> > sdhci_cdns_hs400_enhanced_strobe;
> > @@ -398,9 +453,11 @@ static int sdhci_cdns_probe(struct platform_device *pdev)
> > if (ret)
> > goto free;
> >
> > - sdhci_cdns_sd4_phy_param_parse(dev->of_node, priv);
> > + ret = data->phy_probe(pdev, priv);
> > + if (ret)
> > + goto free;
> >
> > - ret = sdhci_cdns_sd4_phy_init(priv);
> > + ret = priv->cdns_data->phy_init(priv);
>
> As was pointed out last time, you are dereferncing cdns_data unconditionally
> when it could be NULL e.g. in the case of sdhci_cdns_uniphier_of_data
>
> > if (ret)
> > goto free;
> >
> > @@ -429,7 +486,7 @@ static int sdhci_cdns_resume(struct device *dev)
> > if (ret)
> > return ret;
> >
> > - ret = sdhci_cdns_sd4_phy_init(priv);
> > + ret = priv->cdns_data->phy_init(priv);
> > if (ret)
> > goto disable_clk;
> >
> > @@ -453,9 +510,12 @@ static const struct dev_pm_ops sdhci_cdns_pm_ops = {
> > static const struct of_device_id sdhci_cdns_match[] = {
> > {
> > .compatible = "socionext,uniphier-sd4hc",
> > - .data = &sdhci_cdns_uniphier_pltfm_data,
> > + .data = &sdhci_cdns_uniphier_of_data,
> > + },
> > + {
> > + .compatible = "cdns,sd4hc",
> > + .data = &sdhci_cdns_sd4_of_data,
> > },
> > - { .compatible = "cdns,sd4hc" },
> > { /* sentinel */ }
> > };
> > MODULE_DEVICE_TABLE(of, sdhci_cdns_match);
>

Rest of the comments will take care in next version.

Thanks,
Piyush