RE: [PATCH v2 12/14] mmc: sdhci-pic32: Add PIC32 SDHCI host controller driver

[Paul.Thacker]

On 12/16/2015 3:48 AM, Ulf Hansson wrote:
> 
> [...]
> 
> > +static int pic32_sdhci_probe(struct platform_device *pdev) {
> > +       struct device *dev = &pdev->dev;
> > +       struct sdhci_host *host;
> > +       struct resource *iomem;
> > +       struct pic32_sdhci_pdata *sdhci_pdata;
> > +       struct pic32_sdhci_platform_data *plat_data;
> > +       unsigned int clk_rate = 0;
> > +       int ret;
> > +       struct pinctrl *pinctrl;
> > +
> > +       host = sdhci_alloc_host(dev, sizeof(*sdhci_pdata));
> > +       if (IS_ERR(host)) {
> > +               ret = PTR_ERR(host);
> > +               dev_err(&pdev->dev, "cannot allocate memory for sdhci\n");
> > +               goto err;
> > +       }
> > +
> > +       sdhci_pdata = sdhci_priv(host);
> > +       sdhci_pdata->pdev = pdev;
> > +       platform_set_drvdata(pdev, host);
> > +
> > +       iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > +       host->ioaddr = devm_ioremap_resource(&pdev->dev, iomem);
> > +       if (IS_ERR(host->ioaddr)) {
> > +               ret = PTR_ERR(host->ioaddr);
> > +               dev_err(&pdev->dev, "unable to map iomem: %d\n", ret);
> > +               goto err_host;
> > +       }
> > +
> > +       plat_data = pdev->dev.platform_data;
> > +       if (plat_data && plat_data->setup_dma) {
> > +               ret = plat_data->setup_dma(ADMA_FIFO_RD_THSHLD,
> > +                                          ADMA_FIFO_WR_THSHLD);
> > +               if (ret)
> > +                       goto err_host;
> > +       }
> > +
> > +       pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
> 
> This isn't need as it's already handled by the PM core.

Ack. Will remove.

> 
> > +       if (IS_ERR(pinctrl)) {
> > +               ret = PTR_ERR(pinctrl);
> > +               dev_warn(&pdev->dev, "No pinctrl provided %d\n", ret);
> > +               if (ret == -EPROBE_DEFER)
> > +                       goto err_host;
> > +       }
> > +
> > +       host->ops = &pic32_sdhci_ops;
> > +       host->irq = platform_get_irq(pdev, 0);
> > +
> > +       sdhci_pdata->sys_clk = devm_clk_get(&pdev->dev, "sys_clk");
> > +       if (IS_ERR(sdhci_pdata->sys_clk)) {
> > +               ret = PTR_ERR(sdhci_pdata->sys_clk);
> > +               dev_err(&pdev->dev, "Error getting clock\n");
> > +               goto err_host;
> > +       }
> > +
> > +       /* Enable clock when available! */
> > +       ret = clk_prepare_enable(sdhci_pdata->sys_clk);
> > +       if (ret) {
> > +               dev_dbg(&pdev->dev, "Error enabling clock\n");
> > +               goto err_host;
> > +       }
> > +
> > +       /* SDH CLK enable */
> > +       sdhci_pdata->base_clk = devm_clk_get(&pdev->dev, "base_clk");
> > +       if (IS_ERR(sdhci_pdata->base_clk)) {
> > +               ret = PTR_ERR(sdhci_pdata->base_clk);
> > +               dev_err(&pdev->dev, "Error getting clock\n");
> > +               goto err_host;
> > +       }
> > +
> > +       /* Enable clock when available! */
> > +       ret = clk_prepare_enable(sdhci_pdata->base_clk);
> > +       if (ret) {
> > +               dev_dbg(&pdev->dev, "Error enabling clock\n");
> > +               goto err_host;
> > +       }
> > +
> > +       clk_rate = clk_get_rate(sdhci_pdata->base_clk);
> > +       dev_dbg(&pdev->dev, "base clock at: %u\n", clk_rate);
> > +       clk_rate = clk_get_rate(sdhci_pdata->sys_clk);
> > +       dev_dbg(&pdev->dev, "sys clock at: %u\n", clk_rate);
> 
> This looks like some leftover from a debugging task. Can you remove them?
> 

Yes, these are not needed and will be removed.

> > +
> > +       host->quirks2 |= SDHCI_QUIRK2_NO_1_8_V;
> > +
> > +       host->quirks |= SDHCI_QUIRK_NO_HISPD_BIT;
> > +
> > +       ret = mmc_of_parse(host->mmc);
> > +       if (ret)
> 
> From this point, the error handling doesn't undo clk_prepare_enable().
> Please add that.

Ack. Will do.

> 
> > +               goto err_host;
> > +
> > +       ret = pic32_sdhci_probe_platform(pdev, sdhci_pdata);
> > +       if (ret) {
> > +               dev_err(&pdev->dev, "failed to probe platform!\n");
> > +               goto err_host;
> > +       }
> > +
> > +       ret = sdhci_add_host(host);
> > +       if (ret) {
> > +               dev_dbg(&pdev->dev, "error adding host\n");
> > +               goto err_host;
> > +       }
> > +
> > +       dev_info(&pdev->dev, "Successfully added sdhci host\n");
> > +       return 0;
> > +
> > +err_host:
> > +       sdhci_free_host(host);
> > +err:
> > +       dev_err(&pdev->dev, "pic32-sdhci probe failed: %d\n", ret);
> > +       return ret;
> 
> A general comment for the ->probe() and the below ->remove() callback, is that
> you should probably be able to convert to use
> sdhci_pltfm_init() and sdhci_pltfm_free() in favor of
> sdhci_alloc_host() and sdhci_free_host().
> 
> I think that could simplify the code a bit.

Ok. Will do.

> 
> > +}
> > +
> > +static int pic32_sdhci_remove(struct platform_device *pdev) {
> > +       struct sdhci_host *host = platform_get_drvdata(pdev);
> > +       struct pic32_sdhci_pdata *sdhci_pdata = sdhci_priv(host);
> > +       int dead = 0;
> > +       u32 scratch;
> > +
> > +       scratch = readl(host->ioaddr + SDHCI_INT_STATUS);
> > +       if (scratch == (u32)-1)
> > +               dead = 1;
> > +
> > +       sdhci_remove_host(host, dead);
> > +       clk_disable_unprepare(sdhci_pdata->base_clk);
> > +       clk_disable_unprepare(sdhci_pdata->sys_clk);
> > +       sdhci_free_host(host);
> > +
> > +       return 0;
> > +}
> > +
> > +static const struct of_device_id pic32_sdhci_id_table[] = {
> > +       { .compatible = "microchip,pic32mzda-sdhci" },
> > +       {}
> > +};
> > +MODULE_DEVICE_TABLE(of, pic32_sdhci_id_table);
> > +
> > +static struct platform_driver pic32_sdhci_driver = {
> > +       .driver = {
> > +               .name   = DEV_NAME,
> > +               .owner  = THIS_MODULE,
> > +               .of_match_table = of_match_ptr(pic32_sdhci_id_table),
> > +       },
> > +       .probe          = pic32_sdhci_probe,
> > +       .remove         = pic32_sdhci_remove,
> > +};
> > +
> > +module_platform_driver(pic32_sdhci_driver);
> > +
> > +MODULE_DESCRIPTION("Microchip PIC32 SDHCI driver");
> > +MODULE_AUTHOR("Pistirica Sorin Andrei & Sandeep Sheriker");
> > +MODULE_LICENSE("GPL v2");
> > --
> > 1.7.9.5

Thanks,
Paul