On Mon, Jan 10, 2022 at 05:39:36PM -0500, Gabriel L. Somlo wrote: > On Tue, Jan 11, 2022 at 07:15:42AM +0900, Stafford Horne wrote: > > 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); > > I'd prefer to declare victory *after* calling mmc_add_host(), so if > there are no objections I'd prefer to do the following in v12: > > ... > platform_set_drvdata(pdev, host); > > - return mmc_add_host(mmc); > + ret = mmc_add_host(mmc); > + if (ret) > + return dev_err_probe(dev, ret, "LiteX MMC probe failed!\n"); > + > + dev_info(dev, "LiteX MMC controller initialized.\n"); > + > + return 0; > } Yes, that is what I was thinking too. -Stafford
