/* * Copyright (C) 2004 Embedded Edge, LLC * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * */ #include #include #include #include #include #include #include #include #include #include struct au1550nd_ctx { struct nand_chip chip; int cs; void __iomem *base; void (*write_byte)(struct mtd_info *, u_char); }; /** * au_read_byte - read one byte from the chip * @mtd: MTD device structure * * read function for 8bit buswidth */ static u_char au_read_byte(struct mtd_info *mtd) { struct nand_chip *this = mtd_to_nand(mtd); u_char ret = readb(this->IO_ADDR_R); wmb(); /* drain writebuffer */ return ret; } /** * au_write_byte - write one byte to the chip * @mtd: MTD device structure * @byte: pointer to data byte to write * * write function for 8it buswidth */ static void au_write_byte(struct mtd_info *mtd, u_char byte) { struct nand_chip *this = mtd_to_nand(mtd); writeb(byte, this->IO_ADDR_W); wmb(); /* drain writebuffer */ } /** * au_read_byte16 - read one byte endianness aware from the chip * @mtd: MTD device structure * * read function for 16bit buswidth with endianness conversion */ static u_char au_read_byte16(struct mtd_info *mtd) { struct nand_chip *this = mtd_to_nand(mtd); u_char ret = (u_char) cpu_to_le16(readw(this->IO_ADDR_R)); wmb(); /* drain writebuffer */ return ret; } /** * au_write_byte16 - write one byte endianness aware to the chip * @mtd: MTD device structure * @byte: pointer to data byte to write * * write function for 16bit buswidth with endianness conversion */ static void au_write_byte16(struct mtd_info *mtd, u_char byte) { struct nand_chip *this = mtd_to_nand(mtd); writew(le16_to_cpu((u16) byte), this->IO_ADDR_W); wmb(); /* drain writebuffer */ } /** * au_write_buf - write buffer to chip * @mtd: MTD device structure * @buf: data buffer * @len: number of bytes to write * * write function for 8bit buswidth */ static void au_write_buf(struct mtd_info *mtd, const u_char *buf, int len) { int i; struct nand_chip *this = mtd_to_nand(mtd); for (i = 0; i < len; i++) { writeb(buf[i], this->IO_ADDR_W); wmb(); /* drain writebuffer */ } } /** * au_read_buf - read chip data into buffer * @mtd: MTD device structure * @buf: buffer to store date * @len: number of bytes to read * * read function for 8bit buswidth */ static void au_read_buf(struct mtd_info *mtd, u_char *buf, int len) { int i; struct nand_chip *this = mtd_to_nand(mtd); for (i = 0; i < len; i++) { buf[i] = readb(this->IO_ADDR_R); wmb(); /* drain writebuffer */ } } /** * au_write_buf16 - write buffer to chip * @mtd: MTD device structure * @buf: data buffer * @len: number of bytes to write * * write function for 16bit buswidth */ static void au_write_buf16(struct mtd_info *mtd, const u_char *buf, int len) { int i; struct nand_chip *this = mtd_to_nand(mtd); u16 *p = (u16 *) buf; len >>= 1; for (i = 0; i < len; i++) { writew(p[i], this->IO_ADDR_W); wmb(); /* drain writebuffer */ } } /** * au_read_buf16 - read chip data into buffer * @mtd: MTD device structure * @buf: buffer to store date * @len: number of bytes to read * * read function for 16bit buswidth */ static void au_read_buf16(struct mtd_info *mtd, u_char *buf, int len) { int i; struct nand_chip *this = mtd_to_nand(mtd); u16 *p = (u16 *) buf; len >>= 1; for (i = 0; i < len; i++) { p[i] = readw(this->IO_ADDR_R); wmb(); /* drain writebuffer */ } } /* Select the chip by setting nCE to low */ #define NAND_CTL_SETNCE 1 /* Deselect the chip by setting nCE to high */ #define NAND_CTL_CLRNCE 2 /* Select the command latch by setting CLE to high */ #define NAND_CTL_SETCLE 3 /* Deselect the command latch by setting CLE to low */ #define NAND_CTL_CLRCLE 4 /* Select the address latch by setting ALE to high */ #define NAND_CTL_SETALE 5 /* Deselect the address latch by setting ALE to low */ #define NAND_CTL_CLRALE 6 static void au1550_hwcontrol(struct mtd_info *mtd, int cmd) { struct nand_chip *this = mtd_to_nand(mtd); struct au1550nd_ctx *ctx = container_of(this, struct au1550nd_ctx, chip); switch (cmd) { case NAND_CTL_SETCLE: this->IO_ADDR_W = ctx->base + MEM_STNAND_CMD; break; case NAND_CTL_CLRCLE: this->IO_ADDR_W = ctx->base + MEM_STNAND_DATA; break; case NAND_CTL_SETALE: this->IO_ADDR_W = ctx->base + MEM_STNAND_ADDR; break; case NAND_CTL_CLRALE: this->IO_ADDR_W = ctx->base + MEM_STNAND_DATA; /* FIXME: Nobody knows why this is necessary, * but it works only that way */ udelay(1); break; case NAND_CTL_SETNCE: /* assert (force assert) chip enable */ alchemy_wrsmem((1 << (4 + ctx->cs)), AU1000_MEM_STNDCTL); break; case NAND_CTL_CLRNCE: /* deassert chip enable */ alchemy_wrsmem(0, AU1000_MEM_STNDCTL); break; } this->IO_ADDR_R = this->IO_ADDR_W; wmb(); /* Drain the writebuffer */ } int au1550_device_ready(struct mtd_info *mtd) { return (alchemy_rdsmem(AU1000_MEM_STSTAT) & 0x1) ? 1 : 0; } /** * au1550_select_chip - control -CE line * Forbid driving -CE manually permitting the NAND controller to do this. * Keeping -CE asserted during the whole sector reads interferes with the * NOR flash and PCMCIA drivers as it causes contention on the static bus. * We only have to hold -CE low for the NAND read commands since the flash * chip needs it to be asserted during chip not ready time but the NAND * controller keeps it released. * * @mtd: MTD device structure * @chip: chipnumber to select, -1 for deselect */ static void au1550_select_chip(struct mtd_info *mtd, int chip) { } /** * au1550_command - Send command to NAND device * @mtd: MTD device structure * @command: the command to be sent * @column: the column address for this command, -1 if none * @page_addr: the page address for this command, -1 if none */ static void au1550_command(struct mtd_info *mtd, unsigned command, int column, int page_addr) { struct nand_chip *this = mtd_to_nand(mtd); struct au1550nd_ctx *ctx = container_of(this, struct au1550nd_ctx, chip); int ce_override = 0, i; unsigned long flags = 0; /* Begin command latch cycle */ au1550_hwcontrol(mtd, NAND_CTL_SETCLE); /* * Write out the command to the device. */ if (command == NAND_CMD_SEQIN) { int readcmd; if (column >= mtd->writesize) { /* OOB area */ column -= mtd->writesize; readcmd = NAND_CMD_READOOB; } else if (column < 256) { /* First 256 bytes --> READ0 */ readcmd = NAND_CMD_READ0; } else { column -= 256; readcmd = NAND_CMD_READ1; } ctx->write_byte(mtd, readcmd); } ctx->write_byte(mtd, command); /* Set ALE and clear CLE to start address cycle */ au1550_hwcontrol(mtd, NAND_CTL_CLRCLE); if (column != -1 || page_addr != -1) { au1550_hwcontrol(mtd, NAND_CTL_SETALE); /* Serially input address */ if (column != -1) { /* Adjust columns for 16 bit buswidth */ if (this->options & NAND_BUSWIDTH_16 && !nand_opcode_8bits(command)) column >>= 1; ctx->write_byte(mtd, column); } if (page_addr != -1) { ctx->write_byte(mtd, (u8)(page_addr & 0xff)); if (command == NAND_CMD_READ0 || command == NAND_CMD_READ1 || command == NAND_CMD_READOOB) { /* * NAND controller will release -CE after * the last address byte is written, so we'll * have to forcibly assert it. No interrupts * are allowed while we do this as we don't * want the NOR flash or PCMCIA drivers to * steal our precious bytes of data... */ ce_override = 1; local_irq_save(flags); au1550_hwcontrol(mtd, NAND_CTL_SETNCE); } ctx->write_byte(mtd, (u8)(page_addr >> 8)); if (this->options & NAND_ROW_ADDR_3) ctx->write_byte(mtd, ((page_addr >> 16) & 0x0f)); } /* Latch in address */ au1550_hwcontrol(mtd, NAND_CTL_CLRALE); } /* * Program and erase have their own busy handlers. * Status and sequential in need no delay. */ switch (command) { case NAND_CMD_PAGEPROG: case NAND_CMD_ERASE1: case NAND_CMD_ERASE2: case NAND_CMD_SEQIN: case NAND_CMD_STATUS: return; case NAND_CMD_RESET: break; case NAND_CMD_READ0: case NAND_CMD_READ1: case NAND_CMD_READOOB: /* Check if we're really driving -CE low (just in case) */ if (unlikely(!ce_override)) break; /* Apply a short delay always to ensure that we do wait tWB. */ ndelay(100); /* Wait for a chip to become ready... */ for (i = this->chip_delay; !this->dev_ready(mtd) && i > 0; --i) udelay(1); /* Release -CE and re-enable interrupts. */ au1550_hwcontrol(mtd, NAND_CTL_CLRNCE); local_irq_restore(flags); return; } /* Apply this short delay always to ensure that we do wait tWB. */ ndelay(100); while(!this->dev_ready(mtd)); } static int find_nand_cs(unsigned long nand_base) { void __iomem *base = (void __iomem *)KSEG1ADDR(AU1000_STATIC_MEM_PHYS_ADDR); unsigned long addr, staddr, start, mask, end; int i; for (i = 0; i < 4; i++) { addr = 0x1000 + (i * 0x10); /* CSx */ staddr = __raw_readl(base + addr + 0x08); /* STADDRx */ /* figure out the decoded range of this CS */ start = (staddr << 4) & 0xfffc0000; mask = (staddr << 18) & 0xfffc0000; end = (start | (start - 1)) & ~(start ^ mask); if ((nand_base >= start) && (nand_base < end)) return i; } return -ENODEV; } static int au1550nd_probe(struct platform_device *pdev) { struct au1550nd_platdata *pd; struct au1550nd_ctx *ctx; struct nand_chip *this; struct mtd_info *mtd; struct resource *r; int ret, cs; pd = dev_get_platdata(&pdev->dev); if (!pd) { dev_err(&pdev->dev, "missing platform data\n"); return -ENODEV; } ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); if (!ctx) return -ENOMEM; r = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (!r) { dev_err(&pdev->dev, "no NAND memory resource\n"); ret = -ENODEV; goto out1; } if (request_mem_region(r->start, resource_size(r), "au1550-nand")) { dev_err(&pdev->dev, "cannot claim NAND memory area\n"); ret = -ENOMEM; goto out1; } ctx->base = ioremap_nocache(r->start, 0x1000); if (!ctx->base) { dev_err(&pdev->dev, "cannot remap NAND memory area\n"); ret = -ENODEV; goto out2; } this = &ctx->chip; mtd = nand_to_mtd(this); mtd->dev.parent = &pdev->dev; /* figure out which CS# r->start belongs to */ cs = find_nand_cs(r->start); if (cs < 0) { dev_err(&pdev->dev, "cannot detect NAND chipselect\n"); ret = -ENODEV; goto out3; } ctx->cs = cs; this->dev_ready = au1550_device_ready; this->select_chip = au1550_select_chip; this->cmdfunc = au1550_command; /* 30 us command delay time */ this->chip_delay = 30; this->ecc.mode = NAND_ECC_SOFT; this->ecc.algo = NAND_ECC_HAMMING; if (pd->devwidth) this->options |= NAND_BUSWIDTH_16; this->read_byte = (pd->devwidth) ? au_read_byte16 : au_read_byte; ctx->write_byte = (pd->devwidth) ? au_write_byte16 : au_write_byte; this->write_buf = (pd->devwidth) ? au_write_buf16 : au_write_buf; this->read_buf = (pd->devwidth) ? au_read_buf16 : au_read_buf; ret = nand_scan(this, 1); if (ret) { dev_err(&pdev->dev, "NAND scan failed with %d\n", ret); goto out3; } mtd_device_register(mtd, pd->parts, pd->num_parts); platform_set_drvdata(pdev, ctx); return 0; out3: iounmap(ctx->base); out2: release_mem_region(r->start, resource_size(r)); out1: kfree(ctx); return ret; } static int au1550nd_remove(struct platform_device *pdev) { struct au1550nd_ctx *ctx = platform_get_drvdata(pdev); struct resource *r = platform_get_resource(pdev, IORESOURCE_MEM, 0); nand_release(nand_to_mtd(&ctx->chip)); iounmap(ctx->base); release_mem_region(r->start, 0x1000); kfree(ctx); return 0; } static struct platform_driver au1550nd_driver = { .driver = { .name = "au1550-nand", }, .probe = au1550nd_probe, .remove = au1550nd_remove, }; module_platform_driver(au1550nd_driver); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Embedded Edge, LLC"); MODULE_DESCRIPTION("Board-specific glue layer for NAND flash on Pb1550 board");