MXC: mxc_nand: set NFC registers after reset

This patch allows the mxc_nand driver to reset the NAND flash controller. NFC registers are (re-)set after completion of the reset, as a reset will have reverted the NFC registers to their default values.

---
diff -u -r -N linux-2.6.33.2/drivers/mtd/nand/mxc_nand.c linux-2.6.33.2-reset/drivers/mtd/nand/mxc_nand.c
--- linux-2.6.33.2/drivers/mtd/nand/mxc_nand.c 2010-04-02
01:02:33.000000000 +0200
+++ linux-2.6.33.2-reset/drivers/mtd/nand/mxc_nand.c 2010-04-08
15:54:10.000000000 +0200
@@ -542,6 +542,41 @@
}
}

+static void preset(struct mtd_info *mtd)
+{
+ struct nand_chip *nand_chip = mtd->priv;
+ struct mxc_nand_host *host = nand_chip->priv;
+ uint16_t tmp;
+
+ /* disable interrupt, disable spare enable */
+ tmp = readw(host->regs + NFC_CONFIG1);
+ tmp |= NFC_INT_MSK;
+ tmp &= ~NFC_SP_EN;
+ if (nand_chip->ecc.mode == NAND_ECC_HW) {
+ tmp |= NFC_ECC_EN;
+ } else {
+ tmp &= ~NFC_ECC_EN;
+ }
+ writew(tmp, host->regs + NFC_CONFIG1);
+ /* preset operation */
+
+ /* Unlock the internal RAM Buffer */
+ writew(0x2, host->regs + NFC_CONFIG);
+
+ /* Blocks to be unlocked */
+ if (nfc_is_v21()) {
+ writew(0x0, host->regs + NFC_V21_UNLOCKSTART_BLKADDR);
+ writew(0xffff, host->regs + NFC_V21_UNLOCKEND_BLKADDR);
+ } else if (nfc_is_v1()) {
+ writew(0x0, host->regs + NFC_V1_UNLOCKSTART_BLKADDR);
+ writew(0x4000, host->regs + NFC_V1_UNLOCKEND_BLKADDR);
+ } else
+ BUG();
+
+ /* Unlock Block Command for given address range */
+ writew(0x4, host->regs + NFC_WRPROT);
+}
+
/* Used by the upper layer to write command to NAND Flash for
* different operations to be carried out on NAND Flash */
static void mxc_nand_command(struct mtd_info *mtd, unsigned command,
@@ -559,6 +594,10 @@

/* Command pre-processing step */
switch (command) {
+ case NAND_CMD_RESET:
+ send_cmd(host, command, false);
+ preset(mtd);
+ break;

case NAND_CMD_STATUS:
host->buf_start = 0;
@@ -679,7 +718,6 @@
struct mxc_nand_platform_data *pdata = pdev->dev.platform_data; struct mxc_nand_host *host;
struct resource *res;
- uint16_t tmp;
int err = 0, nr_parts = 0;
struct nand_ecclayout *oob_smallpage, *oob_largepage;

@@ -743,51 +781,17 @@
host->spare_len = 64; oob_smallpage = &nandv2_hw_eccoob_smallpage; oob_largepage = &nandv2_hw_eccoob_largepage;
+ this->ecc.bytes = 9;
} else if (nfc_is_v1()) {
host->regs = host->base; host->spare0 = host->base + 0x800; host->spare_len = 16; oob_smallpage = &nandv1_hw_eccoob_smallpage; oob_largepage = &nandv1_hw_eccoob_largepage;
- } else
- BUG();
-
- /* disable interrupt and spare enable */
- tmp = readw(host->regs + NFC_CONFIG1);
- tmp |= NFC_INT_MSK;
- tmp &= ~NFC_SP_EN;
- writew(tmp, host->regs + NFC_CONFIG1);
-
- init_waitqueue_head(&host->irq_waitq);
-
- host->irq = platform_get_irq(pdev, 0);
-
- err = request_irq(host->irq, mxc_nfc_irq, 0, DRIVER_NAME, host);
- if (err)
- goto eirq;
-
- /* Reset NAND */
- this->cmdfunc(mtd, NAND_CMD_RESET, -1, -1);
-
- /* preset operation */
- /* Unlock the internal RAM Buffer */
- writew(0x2, host->regs + NFC_CONFIG);
-
- /* Blocks to be unlocked */
- if (nfc_is_v21()) {
- writew(0x0, host->regs + NFC_V21_UNLOCKSTART_BLKADDR);
- writew(0xffff, host->regs + NFC_V21_UNLOCKEND_BLKADDR);
- this->ecc.bytes = 9;
- } else if (nfc_is_v1()) {
- writew(0x0, host->regs + NFC_V1_UNLOCKSTART_BLKADDR);
- writew(0x4000, host->regs + NFC_V1_UNLOCKEND_BLKADDR);
this->ecc.bytes = 3;
} else
BUG();

- /* Unlock Block Command for given address range */
- writew(0x4, host->regs + NFC_WRPROT);
-
this->ecc.size = 512;
this->ecc.layout = oob_smallpage;

@@ -796,14 +800,8 @@
this->ecc.hwctl = mxc_nand_enable_hwecc; this->ecc.correct = mxc_nand_correct_data; this->ecc.mode = NAND_ECC_HW;
- tmp = readw(host->regs + NFC_CONFIG1);
- tmp |= NFC_ECC_EN;
- writew(tmp, host->regs + NFC_CONFIG1);
} else {
this->ecc.mode = NAND_ECC_SOFT;
- tmp = readw(host->regs + NFC_CONFIG1);
- tmp &= ~NFC_ECC_EN;
- writew(tmp, host->regs + NFC_CONFIG1);
}

/* NAND bus width determines access funtions used by upper layer */
@@ -817,6 +815,14 @@
this->options |= NAND_USE_FLASH_BBT;
}

+ init_waitqueue_head(&host->irq_waitq);
+
+ host->irq = platform_get_irq(pdev, 0);
+
+ err = request_irq(host->irq, mxc_nfc_irq, 0, DRIVER_NAME, host);
+ if (err)
+ goto eirq;
+
/* first scan to find the device and get the page size */ if (nand_scan_ident(mtd, 1)) {
err = -ENXIO;

Both applied to mxc-master.

I usually prefer pushing these patches via the mtd tree but they too often get stuck somewhere. I found several mxc-nand related patches in mtd-master, one of them fixing the not implemented reset command.

Sascha

Pengutronix e.K.                           |                             |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |