drivers/mtd/nand/raw/orion_nand.c

Source file repositories/reference/linux-study-clean/drivers/mtd/nand/raw/orion_nand.c

File Facts

System
Linux kernel
Corpus path
drivers/mtd/nand/raw/orion_nand.c
Extension
.c
Size
5627 bytes
Lines
230
Domain
Driver Families
Bucket
drivers/mtd
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

struct orion_nand_info {
	struct nand_controller controller;
	struct nand_chip chip;
	struct clk *clk;
};

static void orion_nand_cmd_ctrl(struct nand_chip *nc, int cmd,
				unsigned int ctrl)
{
	struct orion_nand_data *board = nand_get_controller_data(nc);
	u32 offs;

	if (cmd == NAND_CMD_NONE)
		return;

	if (ctrl & NAND_CLE)
		offs = (1 << board->cle);
	else if (ctrl & NAND_ALE)
		offs = (1 << board->ale);
	else
		return;

	if (nc->options & NAND_BUSWIDTH_16)
		offs <<= 1;

	writeb(cmd, nc->legacy.IO_ADDR_W + offs);
}

static void orion_nand_read_buf(struct nand_chip *chip, uint8_t *buf, int len)
{
	void __iomem *io_base = chip->legacy.IO_ADDR_R;
#if defined(__LINUX_ARM_ARCH__) && __LINUX_ARM_ARCH__ >= 5
	uint64_t *buf64;
#endif
	int i = 0;

	while (len && (unsigned long)buf & 7) {
		*buf++ = readb(io_base);
		len--;
	}
#if defined(__LINUX_ARM_ARCH__) && __LINUX_ARM_ARCH__ >= 5
	buf64 = (uint64_t *)buf;
	while (i < len/8) {
		/*
		 * Since GCC has no proper constraint (PR 43518)
		 * force x variable to r2/r3 registers as ldrd instruction
		 * requires first register to be even.
		 */
		register uint64_t x asm ("r2");

		asm volatile ("ldrd\t%0, [%1]" : "=&r" (x) : "r" (io_base));
		buf64[i++] = x;
	}
	i *= 8;
#else
	readsl(io_base, buf, len/4);
	i = len / 4 * 4;
#endif
	while (i < len)
		buf[i++] = readb(io_base);
}

static int orion_nand_attach_chip(struct nand_chip *chip)
{
	if (chip->ecc.engine_type == NAND_ECC_ENGINE_TYPE_SOFT &&
	    chip->ecc.algo == NAND_ECC_ALGO_UNKNOWN)
		chip->ecc.algo = NAND_ECC_ALGO_HAMMING;

	return 0;
}

static const struct nand_controller_ops orion_nand_ops = {
	.attach_chip = orion_nand_attach_chip,
};

static int __init orion_nand_probe(struct platform_device *pdev)
{
	struct orion_nand_info *info;
	struct mtd_info *mtd;
	struct nand_chip *nc;
	struct orion_nand_data *board;
	void __iomem *io_base;
	int ret = 0;
	u32 val = 0;

	info = devm_kzalloc(&pdev->dev,
			sizeof(struct orion_nand_info),
			GFP_KERNEL);
	if (!info)
		return -ENOMEM;

Annotation

Implementation Notes