--- /dev/null
+/*
+ * drivers/mtd/nand/au1550nd.c
+ *
+ * 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 <linux/slab.h>
+#include <linux/gpio.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/nand.h>
+#include <linux/mtd/partitions.h>
+#include <linux/platform_device.h>
+#include <asm/io.h>
+#include <asm/mach-au1x00/au1000.h>
+#include <asm/mach-au1x00/au1550nd.h>
+
+
+struct au1550nd_ctx {
+ struct mtd_info info;
+ 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->priv;
+ 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->priv;
+ 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->priv;
+ 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->priv;
+ writew(le16_to_cpu((u16) byte), this->IO_ADDR_W);
+ wmb(); /* drain writebuffer */
+}
+
+/**
+ * au_read_word - read one word from the chip
+ * @mtd: MTD device structure
+ *
+ * read function for 16bit buswidth without endianness conversion
+ */
+static u16 au_read_word(struct mtd_info *mtd)
+{
+ struct nand_chip *this = mtd->priv;
+ u16 ret = readw(this->IO_ADDR_R);
+ wmb(); /* drain writebuffer */
+ return ret;
+}
+
+/**
+ * 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->priv;
+
+ 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->priv;
+
+ 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->priv;
+ 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->priv;
+ 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 au1550nd_ctx *ctx = container_of(mtd, struct au1550nd_ctx, info);
+ struct nand_chip *this = mtd->priv;
+
+ 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 au1550nd_ctx *ctx = container_of(mtd, struct au1550nd_ctx, info);
+ struct nand_chip *this = mtd->priv;
+ 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));
+
+ /* One more address cycle for devices > 32MiB */
+ if (this->chipsize > (32 << 20))
+ 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 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;
+ ctx->info.priv = this;
+ ctx->info.owner = THIS_MODULE;
+
+ /* 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;
+
+ 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->read_word = au_read_word;
+ 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(&ctx->info, 1);
+ if (ret) {
+ dev_err(&pdev->dev, "NAND scan failed with %d\n", ret);
+ goto out3;
+ }
+
+ mtd_device_register(&ctx->info, 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(&ctx->info);
+ 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");
Code Review / kvmfornfv.git / blobdiff