Re: [PATCH v5 2/7] mmc: mediatek: Add Mediatek MMC driver

From: Ulf Hansson
Date: Wed Jun 10 2015 - 07:53:21 EST


[...]

> +static int msdc_drv_probe(struct platform_device *pdev)
> +{
> + struct mmc_host *mmc;
> + struct msdc_host *host;
> + struct resource *res;
> + int ret;
> +
> + if (!pdev->dev.of_node) {
> + dev_err(&pdev->dev, "No DT found\n");
> + return -EINVAL;
> + }
> + /* Allocate MMC host for this device */
> + mmc = mmc_alloc_host(sizeof(struct msdc_host), &pdev->dev);
> + if (!mmc)
> + return -ENOMEM;
> +
> + host = mmc_priv(mmc);
> + ret = mmc_of_parse(mmc);
> + if (ret)
> + goto host_free;
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + host->base = devm_ioremap_resource(&pdev->dev, res);
> + if (IS_ERR(host->base)) {
> + ret = PTR_ERR(host->base);
> + goto host_free;
> + }
> +
> + ret = mmc_regulator_get_supply(mmc);
> + if (ret == -EPROBE_DEFER)
> + goto host_free;
> +
> + host->src_clk = devm_clk_get(&pdev->dev, "source");
> + if (IS_ERR(host->src_clk)) {
> + ret = PTR_ERR(host->src_clk);
> + goto host_free;
> + }
> +
> + host->h_clk = devm_clk_get(&pdev->dev, "hclk");
> + if (IS_ERR(host->h_clk)) {
> + /* host->h_clk is optional, Only for MSDC0/3 at MT8173 */
> + dev_dbg(&pdev->dev,
> + "Invalid hclk from the device tree!\n");
> + }
> +
> + host->irq = platform_get_irq(pdev, 0);
> + if (host->irq < 0) {
> + ret = -EINVAL;
> + goto host_free;
> + }
> +
> + host->pinctrl = devm_pinctrl_get(&pdev->dev);
> + if (IS_ERR(host->pinctrl)) {
> + ret = PTR_ERR(host->pinctrl);
> + dev_err(&pdev->dev, "Cannot find pinctrl!\n");
> + goto host_free;
> + }
> +
> + host->pins_default = pinctrl_lookup_state(host->pinctrl, "default");
> + if (IS_ERR(host->pins_default)) {
> + ret = PTR_ERR(host->pins_default);
> + dev_err(&pdev->dev, "Cannot find pinctrl default!\n");
> + goto host_free;
> + }
> +
> + host->pins_uhs = pinctrl_lookup_state(host->pinctrl, "state_uhs");
> + if (IS_ERR(host->pins_uhs)) {
> + ret = PTR_ERR(host->pins_uhs);
> + dev_err(&pdev->dev, "Cannot find pinctrl uhs!\n");
> + goto host_free;
> + }
> +
> + host->dev = &pdev->dev;
> + host->mmc = mmc;
> + host->hclk = clk_get_rate(host->src_clk);

This looks odd. The clock rate for the source clock is assigned as the
speed of hclk!? Why?

> + /* Set host parameters to mmc */
> + mmc->ops = &mt_msdc_ops;
> + mmc->f_min = host->hclk / (4 * 255);
> +
> + mmc->caps |= MMC_CAP_ERASE | MMC_CAP_CMD23;
> + /* MMC core transfer sizes tunable parameters */
> + mmc->max_segs = MAX_BD_NUM;
> + mmc->max_seg_size = BDMA_DESC_BUFLEN;
> + mmc->max_blk_size = 2048;
> + mmc->max_req_size = 512 * 1024;
> + mmc->max_blk_count = mmc->max_req_size / 512;
> + host->dma_mask = DMA_BIT_MASK(32);
> + mmc_dev(mmc)->dma_mask = &host->dma_mask;
> +
> + host->timeout_clks = 3 * 1048576;
> + host->dma.gpd = dma_alloc_coherent(&pdev->dev,
> + sizeof(struct mt_gpdma_desc),
> + &host->dma.gpd_addr, GFP_KERNEL);
> + host->dma.bd = dma_alloc_coherent(&pdev->dev,
> + MAX_BD_NUM * sizeof(struct mt_bdma_desc),
> + &host->dma.bd_addr, GFP_KERNEL);
> + if (!host->dma.gpd || !host->dma.bd) {
> + ret = -ENOMEM;
> + goto release_mem;
> + }
> + msdc_init_gpd_bd(host, &host->dma);
> + INIT_DELAYED_WORK(&host->req_timeout, msdc_request_timeout);
> + spin_lock_init(&host->lock);
> +
> + platform_set_drvdata(pdev, mmc);
> + msdc_ungate_clock(host);
> + msdc_init_hw(host);
> +
> + ret = devm_request_irq(&pdev->dev, host->irq, msdc_irq,
> + IRQF_TRIGGER_LOW | IRQF_ONESHOT, pdev->name, host);
> + if (ret)
> + goto release;
> +
> + ret = mmc_add_host(mmc);
> + if (ret)
> + goto release;
> +
> + return 0;
> +
> +release:
> + platform_set_drvdata(pdev, NULL);
> + msdc_deinit_hw(host);
> + msdc_gate_clock(host);
> +release_mem:
> + if (host->dma.gpd)
> + dma_free_coherent(&pdev->dev,
> + sizeof(struct mt_gpdma_desc),
> + host->dma.gpd, host->dma.gpd_addr);
> + if (host->dma.bd)
> + dma_free_coherent(&pdev->dev,
> + MAX_BD_NUM * sizeof(struct mt_bdma_desc),
> + host->dma.bd, host->dma.bd_addr);
> +host_free:
> + mmc_free_host(mmc);
> +
> + return ret;
> +}

[...]

Kind regards
Uffe
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