On Sun, Jan 09, 2022 at 06:20:03PM -0500, Gabriel Somlo wrote: > LiteX (https://github.com/enjoy-digital/litex) is a SoC framework > that targets FPGAs. LiteSDCard is a small footprint, configurable > SDCard core commonly used in LiteX designs. > > The driver was first written in May 2020 and has been maintained > cooperatively by the LiteX community. Thanks to all contributors! > > Co-developed-by: Kamil Rakoczy <krakoczy@xxxxxxxxxxxx> > Signed-off-by: Kamil Rakoczy <krakoczy@xxxxxxxxxxxx> > Co-developed-by: Maciej Dudek <mdudek@xxxxxxxxxxxxxxxxxxxxxxxx> > Signed-off-by: Maciej Dudek <mdudek@xxxxxxxxxxxxxxxxxxxxxxxx> > Co-developed-by: Paul Mackerras <paulus@xxxxxxxxxx> > Signed-off-by: Paul Mackerras <paulus@xxxxxxxxxx> > Signed-off-by: Gabriel Somlo <gsomlo@xxxxxxxxx> > Reviewed-by: Joel Stanley <joel@xxxxxxxxx> > Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx> > --- > ... > +static int litex_mmc_probe(struct platform_device *pdev) > +{ > + struct device *dev = &pdev->dev; > + struct litex_mmc_host *host; > + struct mmc_host *mmc; > + struct clk *clk; > + int ret; > + > + /* > + * NOTE: defaults to max_[req,seg]_size=PAGE_SIZE, max_blk_size=512, > + * and max_blk_count accordingly set to 8; > + * If for some reason we need to modify max_blk_count, we must also > + * re-calculate `max_[req,seg]_size = max_blk_size * max_blk_count;` > + */ > + mmc = mmc_alloc_host(sizeof(struct litex_mmc_host), dev); > + if (!mmc) > + return -ENOMEM; > + > + ret = devm_add_action_or_reset(dev, litex_mmc_free_host_wrapper, mmc); > + if (ret) > + return dev_err_probe(dev, ret, > + "Can't register mmc_free_host action\n"); > + > + host = mmc_priv(mmc); > + host->mmc = mmc; > + > + /* Initialize clock source */ > + clk = devm_clk_get(dev, NULL); > + if (IS_ERR(clk)) > + return dev_err_probe(dev, PTR_ERR(clk), "can't get clock\n"); > + host->ref_clk = clk_get_rate(clk); > + host->sd_clk = 0; > + > + /* > + * LiteSDCard only supports 4-bit bus width; therefore, we MUST inject > + * a SET_BUS_WIDTH (acmd6) before the very first data transfer, earlier > + * than when the mmc subsystem would normally get around to it! > + */ > + host->is_bus_width_set = false; > + host->app_cmd = false; > + > + /* LiteSDCard can support 64-bit DMA addressing */ > + ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(64)); > + if (ret) > + return ret; > + > + host->buf_size = mmc->max_req_size * 2; > + host->buffer = dmam_alloc_coherent(dev, host->buf_size, > + &host->dma, GFP_KERNEL); > + if (host->buffer == NULL) > + return -ENOMEM; > + > + host->sdphy = devm_platform_ioremap_resource_byname(pdev, "phy"); > + if (IS_ERR(host->sdphy)) > + return PTR_ERR(host->sdphy); > + > + host->sdcore = devm_platform_ioremap_resource_byname(pdev, "core"); > + if (IS_ERR(host->sdcore)) > + return PTR_ERR(host->sdcore); > + > + host->sdreader = devm_platform_ioremap_resource_byname(pdev, "reader"); > + if (IS_ERR(host->sdreader)) > + return PTR_ERR(host->sdreader); > + > + host->sdwriter = devm_platform_ioremap_resource_byname(pdev, "writer"); > + if (IS_ERR(host->sdwriter)) > + return PTR_ERR(host->sdwriter); > + > + /* Ensure DMA bus masters are disabled */ > + litex_write8(host->sdreader + LITEX_BLK2MEM_ENA, 0); > + litex_write8(host->sdwriter + LITEX_MEM2BLK_ENA, 0); > + > + init_completion(&host->cmd_done); > + ret = litex_mmc_irq_init(pdev, host); > + if (ret) > + return ret; > + > + /* Allow full generic 2.7-3.6V range; no software tuning available */ > + mmc->ocr_avail = LITEX_MMC_OCR; > + > + mmc->ops = &litex_mmc_ops; > + > + /* > + * Set default sd_clk frequency range based on empirical observations > + * of LiteSDCard gateware behavior on typical SDCard media > + */ > + mmc->f_min = 12.5e6; > + mmc->f_max = 50e6; > + > + ret = mmc_of_parse(mmc); > + if (ret) > + return ret; > + > + /* Force 4-bit bus_width (only width supported by hardware) */ > + mmc->caps &= ~MMC_CAP_8_BIT_DATA; > + mmc->caps |= MMC_CAP_4_BIT_DATA; > + > + /* Set default capabilities */ > + mmc->caps |= MMC_CAP_WAIT_WHILE_BUSY | > + MMC_CAP_DRIVER_TYPE_D | > + MMC_CAP_CMD23; > + mmc->caps2 |= MMC_CAP2_NO_WRITE_PROTECT | > + MMC_CAP2_NO_SDIO | > + MMC_CAP2_NO_MMC; > + > + platform_set_drvdata(pdev, host); One more thing here. Or somewhere, should we add: dev_info(dev, "Litex MMC controller initialized"); I was having a hard time debugging probing of this and having no printk's made it a bit difficult. Though I was able to get most of the debug statements I needed using: "debug initcall_debug dyndbg=\"file drivers/* +p\" loglevel=8" -Stafford > + return mmc_add_host(mmc); > +} > +
