#include <linux/slab.h>
#include <linux/init.h>
#include <linux/module.h>
+#include <linux/interrupt.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/nand.h>
#include <linux/mtd/partitions.h>
static struct mtd_info *au1550_mtd = NULL;
static void __iomem *p_nand;
static int nand_width = 1; /* default x8 */
+static void (*au1550_write_byte)(struct mtd_info *, u_char);
/*
* Define partitions for flash device
return ret;
}
-/**
- * au_write_word - write one word to the chip
- * @mtd: MTD device structure
- * @word: data word to write
- *
- * write function for 16bit buswith without
- * endianess conversion
- */
-static void au_write_word(struct mtd_info *mtd, u16 word)
-{
- struct nand_chip *this = mtd->priv;
- writew(word, this->IO_ADDR_W);
- au_sync();
-}
-
/**
* au_write_buf - write buffer to chip
* @mtd: MTD device structure
return 0;
}
+/* 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)
{
return ret;
}
+/**
+ * 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)
+{
+ register struct nand_chip *this = mtd->priv;
+ int ce_override = 0, i;
+ ulong flags;
+
+ /* 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;
+ }
+ au1550_write_byte(mtd, readcmd);
+ }
+ au1550_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)
+ column >>= 1;
+ au1550_write_byte(mtd, column);
+ }
+ if (page_addr != -1) {
+ au1550_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);
+ }
+
+ au1550_write_byte(mtd, (u8)(page_addr >> 8));
+
+ /* One more address cycle for devices > 32MiB */
+ if (this->chipsize > (32 << 20))
+ au1550_write_byte(mtd, (u8)((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));
+}
+
+
/*
* Main initialization routine
*/
nand_width = au_readl(MEM_STCFG3) & (1 << 22);
/* Set address of hardware control function */
- this->hwcontrol = au1550_hwcontrol;
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->eccmode = NAND_ECC_SOFT;
+ this->ecc.mode = NAND_ECC_SOFT;
this->options = NAND_NO_AUTOINCR;
this->options |= NAND_BUSWIDTH_16;
this->read_byte = (!nand_width) ? au_read_byte16 : au_read_byte;
- this->write_byte = (!nand_width) ? au_write_byte16 : au_write_byte;
- this->write_word = au_write_word;
+ au1550_write_byte = (!nand_width) ? au_write_byte16 : au_write_byte;
this->read_word = au_read_word;
this->write_buf = (!nand_width) ? au_write_buf16 : au_write_buf;
this->read_buf = (!nand_width) ? au_read_buf16 : au_read_buf;