From: Liu Shuo <b35...@freescale.com>

Freescale FCM controller has a 2K size limitation of buffer RAM. In order
to support the Nand flash chip whose page size is larger than 2K bytes,
we read/write 2k data repeatedly by issuing FIR_OP_RB/FIR_OP_WB and save
them to a large buffer.

Signed-off-by: Liu Shuo <b35...@freescale.com>
Signed-off-by: Li Yang <le...@freescale.com>
---
 drivers/mtd/nand/fsl_elbc_nand.c |  211 +++++++++++++++++++++++++++++++++++---
 1 files changed, 194 insertions(+), 17 deletions(-)

diff --git a/drivers/mtd/nand/fsl_elbc_nand.c b/drivers/mtd/nand/fsl_elbc_nand.c
index d634c5f..c96e714 100644
--- a/drivers/mtd/nand/fsl_elbc_nand.c
+++ b/drivers/mtd/nand/fsl_elbc_nand.c
@@ -55,7 +55,9 @@ struct fsl_elbc_mtd {
        struct device *dev;
        int bank;               /* Chip select bank number           */
        u8 __iomem *vbase;      /* Chip select base virtual address  */
-       int page_size;          /* NAND page size (0=512, 1=2048)    */
+       int page_size;          /* NAND page size, the mutiple of 2048.
+                                * (0=512, 1=2048, 2=4096, 4=8192....)
+                                */
        unsigned int fmr;       /* FCM Flash Mode Register value     */
 };
 
@@ -75,6 +77,8 @@ struct fsl_elbc_fcm_ctrl {
        unsigned int use_mdr;    /* Non zero if the MDR is to be set      */
        unsigned int oob;        /* Non zero if operating on OOB data     */
        unsigned int counter;    /* counter for the initializations       */
+
+       char *buffer;            /* just be used when pagesize > 2048     */
 };
 
 /* These map to the positions used by the FCM hardware ECC generator */
@@ -150,6 +154,42 @@ static struct nand_bbt_descr bbt_mirror_descr = {
 };
 
 /*=================================*/
+static void io_to_buffer(struct mtd_info *mtd, int subpage, int oob)
+{
+       struct nand_chip *chip = mtd->priv;
+       struct fsl_elbc_mtd *priv = chip->priv;
+       struct fsl_elbc_fcm_ctrl *elbc_fcm_ctrl = priv->ctrl->nand;
+       void *src, *dst;
+       int len = (oob ? 64 : 2048);
+
+       if (oob)
+               dst = elbc_fcm_ctrl->buffer + mtd->writesize + subpage * 64;
+       else
+               dst = elbc_fcm_ctrl->buffer + subpage * 2048;
+
+       src = elbc_fcm_ctrl->addr + (oob ? 2048 : 0);
+       memcpy_fromio(dst, src, len);
+}
+
+static void buffer_to_io(struct mtd_info *mtd, int subpage, int oob)
+{
+       struct nand_chip *chip = mtd->priv;
+       struct fsl_elbc_mtd *priv = chip->priv;
+       struct fsl_elbc_fcm_ctrl *elbc_fcm_ctrl = priv->ctrl->nand;
+       void *src, *dst;
+       int len = (oob ? 64 : 2048);
+
+       if (oob)
+               src = elbc_fcm_ctrl->buffer + mtd->writesize + subpage * 64;
+       else
+               src = elbc_fcm_ctrl->buffer + subpage * 2048;
+
+       dst = elbc_fcm_ctrl->addr + (oob ? 2048 : 0);
+       memcpy_toio(dst, src, len);
+
+       /* See the in_8() in fsl_elbc_write_buf() */
+       in_8(elbc_fcm_ctrl->addr);
+}
 
 /*
  * Set up the FCM hardware block and page address fields, and the fcm
@@ -193,7 +233,7 @@ static void set_addr(struct mtd_info *mtd, int column, int 
page_addr, int oob)
 
        /* for OOB data point to the second half of the buffer */
        if (oob)
-               elbc_fcm_ctrl->index += priv->page_size ? 2048 : 512;
+               elbc_fcm_ctrl->index += mtd->writesize;
 
        dev_vdbg(priv->dev, "set_addr: bank=%d, "
                            "elbc_fcm_ctrl->addr=0x%p (0x%p), "
@@ -311,6 +351,7 @@ static void fsl_elbc_cmdfunc(struct mtd_info *mtd, unsigned 
int command,
        struct fsl_lbc_ctrl *ctrl = priv->ctrl;
        struct fsl_elbc_fcm_ctrl *elbc_fcm_ctrl = ctrl->nand;
        struct fsl_lbc_regs __iomem *lbc = ctrl->regs;
+       int i;
 
        elbc_fcm_ctrl->use_mdr = 0;
 
@@ -339,6 +380,26 @@ static void fsl_elbc_cmdfunc(struct mtd_info *mtd, 
unsigned int command,
 
                fsl_elbc_do_read(chip, 0);
                fsl_elbc_run_command(mtd);
+
+               if (priv->page_size <= 1)
+                       return;
+
+               /* Continue to read the rest bytes if writesize > 2048 */
+               io_to_buffer(mtd, 0, 0);
+               io_to_buffer(mtd, 0, 1);
+
+               out_be32(&lbc->fir, FIR_OP_RB << FIR_OP1_SHIFT);
+
+               for (i = 1; i < priv->page_size; i++) {
+                       /*
+                        * Maybe there are some reasons of FCM hardware timing,
+                        * we must insert a FIR_OP_NOP(0x00) before FIR_OP_RB.
+                        */
+                       fsl_elbc_run_command(mtd);
+                       io_to_buffer(mtd, i, 0);
+                       io_to_buffer(mtd, i, 1);
+               }
+
                return;
 
        /* READOOB reads only the OOB because no ECC is performed. */
@@ -347,13 +408,36 @@ static void fsl_elbc_cmdfunc(struct mtd_info *mtd, 
unsigned int command,
                         "fsl_elbc_cmdfunc: NAND_CMD_READOOB, page_addr:"
                         " 0x%x, column: 0x%x.\n", page_addr, column);
 
-               out_be32(&lbc->fbcr, mtd->oobsize - column);
-               set_addr(mtd, column, page_addr, 1);
+               if (priv->page_size <= 1) {
+                       out_be32(&lbc->fbcr, mtd->oobsize - column);
+                       set_addr(mtd, column, page_addr, 1);
+               } else {
+                       out_be32(&lbc->fbcr, 64);
+                       set_addr(mtd, 0, page_addr, 1);
+                       elbc_fcm_ctrl->index += column;
+               }
 
                elbc_fcm_ctrl->read_bytes = mtd->writesize + mtd->oobsize;
 
                fsl_elbc_do_read(chip, 1);
                fsl_elbc_run_command(mtd);
+
+               if (priv->page_size <= 1)
+                       return;
+
+               if (column < 64)
+                       io_to_buffer(mtd, 0, 1);
+
+               out_be32(&lbc->fbcr, 2112);
+               out_be32(&lbc->fir, FIR_OP_RB << FIR_OP1_SHIFT);
+               out_be32(&lbc->fpar, in_be32(&lbc->fpar) & ~FPAR_LP_MS);
+
+               for (i = 1; i < priv->page_size; i++) {
+                       fsl_elbc_run_command(mtd);
+                       if (column < (64 * (i + 1)))
+                               io_to_buffer(mtd, i, 1);
+               }
+
                return;
 
        /* READID must read all 5 possible bytes while CEB is active */
@@ -429,7 +513,14 @@ static void fsl_elbc_cmdfunc(struct mtd_info *mtd, 
unsigned int command,
                      (NAND_CMD_SEQIN    << FCR_CMD2_SHIFT) |
                      (NAND_CMD_PAGEPROG << FCR_CMD3_SHIFT);
 
-               if (priv->page_size) {
+               if (priv->page_size > 1) {
+                       /* writesize > 2048 */
+                       out_be32(&lbc->fir,
+                                (FIR_OP_CM2 << FIR_OP0_SHIFT) |
+                                (FIR_OP_CA  << FIR_OP1_SHIFT) |
+                                (FIR_OP_PA  << FIR_OP2_SHIFT) |
+                                (FIR_OP_WB  << FIR_OP3_SHIFT));
+               } else if (priv->page_size) {
                        out_be32(&lbc->fir,
                                 (FIR_OP_CM2 << FIR_OP0_SHIFT) |
                                 (FIR_OP_CA  << FIR_OP1_SHIFT) |
@@ -458,7 +549,13 @@ static void fsl_elbc_cmdfunc(struct mtd_info *mtd, 
unsigned int command,
                }
 
                out_be32(&lbc->fcr, fcr);
-               set_addr(mtd, column, page_addr, elbc_fcm_ctrl->oob);
+               if (elbc_fcm_ctrl->oob && priv->page_size > 1) {
+                       set_addr(mtd, 0, page_addr, 0);
+                       elbc_fcm_ctrl->index = elbc_fcm_ctrl->column;
+               } else {
+                       set_addr(mtd, column, page_addr, elbc_fcm_ctrl->oob);
+               }
+
                return;
        }
 
@@ -472,14 +569,59 @@ static void fsl_elbc_cmdfunc(struct mtd_info *mtd, 
unsigned int command,
                 * then set the exact length, otherwise use a full page
                 * write so the HW generates the ECC.
                 */
-               if (elbc_fcm_ctrl->oob || elbc_fcm_ctrl->column != 0 ||
-                   elbc_fcm_ctrl->index != mtd->writesize + mtd->oobsize)
+               if (elbc_fcm_ctrl->oob) {
+                       int len;
+                       /* write oob */
+                       if (priv->page_size > 1) {
+                               /* when pagesize of chip is greater than 2048,
+                                * we have to write full page to write spare
+                                * region, so we fill '0xff' to main region
+                                * and some bytes of spare region which we
+                                * don't want to rewrite.
+                                * (write '1' won't change the original value)
+                                */
+                               memset(elbc_fcm_ctrl->buffer, 0xff,
+                                               elbc_fcm_ctrl->column);
+                               len = 2112;
+                       } else {
+                               len = elbc_fcm_ctrl->index -
+                                               elbc_fcm_ctrl->column;
+                       }
+                       out_be32(&lbc->fbcr, len);
+               } else if (elbc_fcm_ctrl->column != 0 ||
+                   elbc_fcm_ctrl->index != mtd->writesize + mtd->oobsize) {
                        out_be32(&lbc->fbcr,
                                elbc_fcm_ctrl->index - elbc_fcm_ctrl->column);
-               else
+               } else {
                        out_be32(&lbc->fbcr, 0);
+               }
+
+               if (priv->page_size > 1) {
+                       buffer_to_io(mtd, 0, 0);
+                       buffer_to_io(mtd, 0, 1);
+               }
 
                fsl_elbc_run_command(mtd);
+
+               if (priv->page_size <= 1)
+                       return;
+
+               out_be32(&lbc->fir, FIR_OP_WB << FIR_OP1_SHIFT);
+               for (i = 1; i < priv->page_size; i++) {
+                       elbc_fcm_ctrl->use_mdr = 1;
+                       /* For the last subpage */
+                       if (i == priv->page_size - 1)
+                               out_be32(&lbc->fir,
+                                       (FIR_OP_WB  << FIR_OP1_SHIFT) |
+                                       (FIR_OP_CM3 << FIR_OP2_SHIFT) |
+                                       (FIR_OP_CW1 << FIR_OP3_SHIFT) |
+                                       (FIR_OP_RS  << FIR_OP4_SHIFT));
+
+                       buffer_to_io(mtd, i, 0);
+                       buffer_to_io(mtd, i, 1);
+                       fsl_elbc_run_command(mtd);
+               }
+
                return;
        }
 
@@ -548,7 +690,14 @@ static void fsl_elbc_write_buf(struct mtd_info *mtd, const 
u8 *buf, int len)
                len = bufsize - elbc_fcm_ctrl->index;
        }
 
-       memcpy_toio(&elbc_fcm_ctrl->addr[elbc_fcm_ctrl->index], buf, len);
+       if (mtd->writesize > 2048) {
+               memcpy(&elbc_fcm_ctrl->buffer[elbc_fcm_ctrl->index],
+                               buf, len);
+       } else {
+               memcpy_toio(&elbc_fcm_ctrl->addr[elbc_fcm_ctrl->index],
+                               buf, len);
+       }
+
        /*
         * This is workaround for the weird elbc hangs during nand write,
         * Scott Wood says: "...perhaps difference in how long it takes a
@@ -594,7 +743,13 @@ static void fsl_elbc_read_buf(struct mtd_info *mtd, u8 
*buf, int len)
 
        avail = min((unsigned int)len,
                        elbc_fcm_ctrl->read_bytes - elbc_fcm_ctrl->index);
-       memcpy_fromio(buf, &elbc_fcm_ctrl->addr[elbc_fcm_ctrl->index], avail);
+       if (mtd->writesize > 2048) {
+               memcpy(buf, &elbc_fcm_ctrl->buffer[elbc_fcm_ctrl->index],
+                               avail);
+       } else {
+               memcpy_fromio(buf, &elbc_fcm_ctrl->addr[elbc_fcm_ctrl->index],
+                               avail);
+       }
        elbc_fcm_ctrl->index += avail;
 
        if (len > avail)
@@ -630,10 +785,17 @@ static int fsl_elbc_verify_buf(struct mtd_info *mtd, 
const u_char *buf, int len)
                return -EINVAL;
        }
 
-       for (i = 0; i < len; i++)
-               if (in_8(&elbc_fcm_ctrl->addr[elbc_fcm_ctrl->index + i])
-                               != buf[i])
-                       break;
+       if (mtd->writesize > 2048) {
+               for (i = 0; i < len; i++)
+                       if (elbc_fcm_ctrl->buffer[elbc_fcm_ctrl->index + i]
+                                       != buf[i])
+                               break;
+       } else {
+               for (i = 0; i < len; i++)
+                       if (in_8(&elbc_fcm_ctrl->addr[elbc_fcm_ctrl->index + i])
+                                       != buf[i])
+                               break;
+       }
 
        elbc_fcm_ctrl->index += len;
        return i == len && elbc_fcm_ctrl->status == LTESR_CC ? 0 : -EIO;
@@ -716,8 +878,9 @@ static int fsl_elbc_chip_init_tail(struct mtd_info *mtd)
        if (mtd->writesize == 512) {
                priv->page_size = 0;
                clrbits32(&lbc->bank[priv->bank].or, OR_FCM_PGS);
-       } else if (mtd->writesize == 2048) {
-               priv->page_size = 1;
+       } else if (mtd->writesize >= 2048 && mtd->writesize <= 16 * 1024) {
+               priv->page_size = mtd->writesize / 2048;
+
                setbits32(&lbc->bank[priv->bank].or, OR_FCM_PGS);
                /* adjust ecc setup if needed */
                if ((in_be32(&lbc->bank[priv->bank].br) & BR_DECC) ==
@@ -891,6 +1054,19 @@ static int __devinit fsl_elbc_nand_probe(struct 
platform_device *pdev)
                        goto err;
                }
                elbc_fcm_ctrl->counter++;
+               /*
+                * Freescale FCM controller has a 2K size limitation of buffer
+                * RAM, so elbc_fcm_ctrl->buffer have to be used if writesize
+                * of chip is greater than 2048.
+                * We malloc a large enough buffer (maximum page size is 16K).
+                */
+               elbc_fcm_ctrl->buffer = kmalloc(1024 * 16 + 1024, GFP_KERNEL);
+               if (!elbc_fcm_ctrl->buffer) {
+                       dev_err(dev, "failed to allocate memory\n");
+                       mutex_unlock(&fsl_elbc_nand_mutex);
+                       ret = -ENOMEM;
+                       goto err;
+               }
 
                spin_lock_init(&elbc_fcm_ctrl->controller.lock);
                init_waitqueue_head(&elbc_fcm_ctrl->controller.wq);
@@ -960,6 +1136,7 @@ static int fsl_elbc_nand_remove(struct platform_device 
*pdev)
        elbc_fcm_ctrl->counter--;
        if (!elbc_fcm_ctrl->counter) {
                fsl_lbc_ctrl_dev->nand = NULL;
+               kfree(elbc_fcm_ctrl->buffer);
                kfree(elbc_fcm_ctrl);
        }
        mutex_unlock(&fsl_elbc_nand_mutex);
-- 
1.7.1


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