Semc - Flash Device Driver

// 4. Scan for NAND chips nand_scan(chip, 1);

struct semc_nand *priv; struct nand_chip *chip; // 1. Request memory region and clock priv->base = devm_platform_ioremap_resource(pdev, 0); priv->clk = devm_clk_get(&pdev->dev, "semc"); clk_prepare_enable(priv->clk);

static int semc_nand_probe(struct platform_device *pdev) semc flash device driver

// 5. Register to MTD mtd_device_register(mtd, NULL, 0);

// 2. Configure SEMC registers for NAND (timings, bus width) semc_set_nand_timings(priv); Register to MTD mtd_device_register(mtd, NULL, 0); // 2

If you’ve worked on NAND or eMMC management in embedded Linux, you’ve likely come across the term SEMC (Smart External Memory Controller). While often associated with NXP’s i.MX RT and LPC families, the SEMC peripheral is a powerful external memory interface that can be configured to drive various asynchronous/synchronous memory devices—including NOR flash, NAND flash, and even SRAM/PSRAM.

// 3. Initialize NAND controller and assign controller ops chip->controller = &priv->controller; chip->select_chip = semc_nand_select; chip->cmd_ctrl = semc_nand_cmd_ctrl; chip->dev_ready = semc_nand_dev_ready; controller = &priv-&gt

// Correct for 64MB HyperFlash SEMC->BR[0] = (0x60000000 & SEMC_BR_BA_MASK) | SEMC_BR_VLD | (16 << 8) /* burst len */ | (1 << 3) /* addr shift enable */; The SEMC flash driver sits at the intersection of hardware timing and filesystem reliability. Start with a known working example from your MCU vendor’s SDK (NXP’s fsl_semc.c is a good reference), then adapt it to Linux or your RTOS. And always— always —validate with a flash stress test before declaring it production-ready. Have you run into a weird SEMC timing issue? Drop a comment below or ping me on Twitter @embedded_rust.