[MTD] NAND modularize ECC

First step of modularizing ECC support.
- Move ECC related functionality into a seperate embedded data structure
- Get rid of the hardware dependend constants to simplify new ECC models

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 48 insertions, 98 deletions

diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 37db98a58c34..98792ec4c2dc 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -879,9 +879,9 @@ static int nand_write_page(struct mtd_info *mtd, struct nand_chip *this, int pag
 {
         int i, status;
         uint8_t ecc_code[32];
-        int eccmode = oobsel->useecc ? this->eccmode : NAND_ECC_NONE;
+        int eccmode = oobsel->useecc ? this->ecc.mode : NAND_ECC_NONE;
         int *oob_config = oobsel->eccpos;
-        int datidx = 0, eccidx = 0, eccsteps = this->eccsteps;
+        int datidx = 0, eccidx = 0, eccsteps = this->ecc.steps;
         int eccbytes = 0;
 
         /* FIXME: Enable cached programming */
@@ -901,20 +901,20 @@ static int nand_write_page(struct mtd_info *mtd, struct nand_chip *this, int pag
                 /* Software ecc 3/256, write all */
         case NAND_ECC_SOFT:
                 for (; eccsteps; eccsteps--) {
-                        this->calculate_ecc(mtd, &this->data_poi[datidx], ecc_code);
+                        this->ecc.calculate(mtd, &this->data_poi[datidx], ecc_code);
                         for (i = 0; i < 3; i++, eccidx++)
                                 oob_buf[oob_config[eccidx]] = ecc_code[i];
-                        datidx += this->eccsize;
+                        datidx += this->ecc.size;
                 }
                 this->write_buf(mtd, this->data_poi, mtd->oobblock);
                 break;
         default:
-                eccbytes = this->eccbytes;
+                eccbytes = this->ecc.bytes;
                 for (; eccsteps; eccsteps--) {
                         /* enable hardware ecc logic for write */
-                        this->enable_hwecc(mtd, NAND_ECC_WRITE);
-                        this->write_buf(mtd, &this->data_poi[datidx], this->eccsize);
-                        this->calculate_ecc(mtd, &this->data_poi[datidx], ecc_code);
+                        this->ecc.hwctl(mtd, NAND_ECC_WRITE);
+                        this->write_buf(mtd, &this->data_poi[datidx], this->ecc.size);
+                        this->ecc.calculate(mtd, &this->data_poi[datidx], ecc_code);
                         for (i = 0; i < eccbytes; i++, eccidx++)
                                 oob_buf[oob_config[eccidx]] = ecc_code[i];
                         /* If the hardware ecc provides syndromes then
@@ -922,7 +922,7 @@ static int nand_write_page(struct mtd_info *mtd, struct nand_chip *this, int pag
                          * the data bytes (words) */
                         if (this->options & NAND_HWECC_SYNDROME)
                                 this->write_buf(mtd, ecc_code, eccbytes);
-                        datidx += this->eccsize;
+                        datidx += this->ecc.size;
                 }
                 break;
         }
@@ -1155,7 +1155,7 @@ int nand_do_read_ecc(struct mtd_info *mtd, loff_t from, size_t len,
         if (oobsel->useecc == MTD_NANDECC_AUTOPLACE)
                 oobsel = this->autooob;
 
-        eccmode = oobsel->useecc ? this->eccmode : NAND_ECC_NONE;
+        eccmode = oobsel->useecc ? this->ecc.mode : NAND_ECC_NONE;
         oob_config = oobsel->eccpos;
 
         /* Select the NAND device */
@@ -1170,8 +1170,8 @@ int nand_do_read_ecc(struct mtd_info *mtd, loff_t from, size_t len,
         col = from & (mtd->oobblock - 1);
 
         end = mtd->oobblock;
-        ecc = this->eccsize;
-        eccbytes = this->eccbytes;
+        ecc = this->ecc.size;
+        eccbytes = this->ecc.bytes;
 
         if ((eccmode == NAND_ECC_NONE) || (this->options & NAND_HWECC_SYNDROME))
                 compareecc = 0;
@@ -1216,7 +1216,7 @@ int nand_do_read_ecc(struct mtd_info *mtd, loff_t from, size_t len,
                         oobsel->useecc == MTD_NANDECC_AUTOPL_USR)
                         oob_data = &this->data_buf[end];
 
-                eccsteps = this->eccsteps;
+                eccsteps = this->ecc.steps;
 
                 switch (eccmode) {
                 case NAND_ECC_NONE:{
@@ -1234,12 +1234,12 @@ int nand_do_read_ecc(struct mtd_info *mtd, loff_t from, size_t len,
                 case NAND_ECC_SOFT:     /* Software ECC 3/256: Read in a page + oob data */
                         this->read_buf(mtd, data_poi, end);
                         for (i = 0, datidx = 0; eccsteps; eccsteps--, i += 3, datidx += ecc)
-                                this->calculate_ecc(mtd, &data_poi[datidx], &ecc_calc[i]);
+                                this->ecc.calculate(mtd, &data_poi[datidx], &ecc_calc[i]);
                         break;
 
                 default:
                         for (i = 0, datidx = 0; eccsteps; eccsteps--, i += eccbytes, datidx += ecc) {
-                                this->enable_hwecc(mtd, NAND_ECC_READ);
+                                this->ecc.hwctl(mtd, NAND_ECC_READ);
                                 this->read_buf(mtd, &data_poi[datidx], ecc);
 
                                 /* HW ecc with syndrome calculation must read the
@@ -1247,19 +1247,19 @@ int nand_do_read_ecc(struct mtd_info *mtd, loff_t from, size_t len,
                                 if (!compareecc) {
                                         /* Some hw ecc generators need to know when the
                                          * syndrome is read from flash */
-                                        this->enable_hwecc(mtd, NAND_ECC_READSYN);
+                                        this->ecc.hwctl(mtd, NAND_ECC_READSYN);
                                         this->read_buf(mtd, &oob_data[i], eccbytes);
                                         /* We calc error correction directly, it checks the hw
                                          * generator for an error, reads back the syndrome and
                                          * does the error correction on the fly */
-                                        ecc_status = this->correct_data(mtd, &data_poi[datidx], &oob_data[i], &ecc_code[i]);
+                                        ecc_status = this->ecc.correct(mtd, &data_poi[datidx], &oob_data[i], &ecc_code[i]);
                                         if ((ecc_status == -1) || (ecc_status > (flags && 0xff))) {
                                                 DEBUG(MTD_DEBUG_LEVEL0, "nand_read_ecc: "
                                                       "Failed ECC read, page 0x%08x on chip %d\n", page, chipnr);
                                                 ecc_failed++;
                                         }
                                 } else {
-                                        this->calculate_ecc(mtd, &data_poi[datidx], &ecc_calc[i]);
+                                        this->ecc.calculate(mtd, &data_poi[datidx], &ecc_calc[i]);
                                 }
                         }
                         break;
@@ -1277,8 +1277,8 @@ int nand_do_read_ecc(struct mtd_info *mtd, loff_t from, size_t len,
                         ecc_code[j] = oob_data[oob_config[j]];
 
                 /* correct data, if necessary */
-                for (i = 0, j = 0, datidx = 0; i < this->eccsteps; i++, datidx += ecc) {
-                        ecc_status = this->correct_data(mtd, &data_poi[datidx], &ecc_code[j], &ecc_calc[j]);
+                for (i = 0, j = 0, datidx = 0; i < this->ecc.steps; i++, datidx += ecc) {
+                        ecc_status = this->ecc.correct(mtd, &data_poi[datidx], &ecc_code[j], &ecc_calc[j]);
 
                         /* Get next chunk of ecc bytes */
                         j += eccbytes;
@@ -1315,7 +1315,7 @@ int nand_do_read_ecc(struct mtd_info *mtd, loff_t from, size_t len,
                                 break;
                         case MTD_NANDECC_PLACE:
                                 /* YAFFS1 legacy mode */
-                                oob_data += this->eccsteps * sizeof(int);
+                                oob_data += this->ecc.steps * sizeof(int);
                         default:
                                 oob_data += mtd->oobsize;
                         }
@@ -2648,99 +2648,49 @@ int nand_scan(struct mtd_info *mtd, int maxchips)
          * check ECC mode, default to software if 3byte/512byte hardware ECC is
          * selected and we have 256 byte pagesize fallback to software ECC
          */
-        this->eccsize = 256;
-        this->eccbytes = 3;
-
-        switch (this->eccmode) {
-        case NAND_ECC_HW12_2048:
-                if (mtd->oobblock < 2048) {
-                        printk(KERN_WARNING "2048 byte HW ECC not possible on "
-                               "%d byte page size, fallback to SW ECC\n",
-                               mtd->oobblock);
-                        this->eccmode = NAND_ECC_SOFT;
-                        this->calculate_ecc = nand_calculate_ecc;
-                        this->correct_data = nand_correct_data;
-                } else
-                        this->eccsize = 2048;
-                break;
-
-        case NAND_ECC_HW3_512:
-        case NAND_ECC_HW6_512:
-        case NAND_ECC_HW8_512:
-                if (mtd->oobblock == 256) {
-                        printk(KERN_WARNING "512 byte HW ECC not possible on "
-                               "256 Byte pagesize, fallback to SW ECC \n");
-                        this->eccmode = NAND_ECC_SOFT;
-                        this->calculate_ecc = nand_calculate_ecc;
-                        this->correct_data = nand_correct_data;
-                } else
-                        this->eccsize = 512;    /* set eccsize to 512 */
-                break;
+        switch (this->ecc.mode) {
+        case NAND_ECC_HW:
+        case NAND_ECC_HW_SYNDROME:
+                if (!this->ecc.calculate || !this->ecc.correct ||
+                    !this->ecc.hwctl) {
+                        printk(KERN_WARNING "No ECC functions supplied, "
+                               "Hardware ECC not possible\n");
+                        BUG();
+                }
+                if (mtd->oobblock >= this->ecc.size)
+                        break;
+                printk(KERN_WARNING "%d byte HW ECC not possible on "
+                       "%d byte page size, fallback to SW ECC\n",
+                       this->ecc.size, mtd->oobblock);
+                this->ecc.mode = NAND_ECC_SOFT;
 
-        case NAND_ECC_HW3_256:
+        case NAND_ECC_SOFT:
+                this->ecc.calculate = nand_calculate_ecc;
+                this->ecc.correct = nand_correct_data;
+                this->ecc.size = 256;
+                this->ecc.bytes = 3;
                 break;
 
         case NAND_ECC_NONE:
                 printk(KERN_WARNING "NAND_ECC_NONE selected by board driver. "
                        "This is not recommended !!\n");
-                this->eccmode = NAND_ECC_NONE;
+                this->ecc.size = mtd->oobblock;
+                this->ecc.bytes = 0;
                 break;
-
-        case NAND_ECC_SOFT:
-                this->calculate_ecc = nand_calculate_ecc;
-                this->correct_data = nand_correct_data;
-                break;
-
         default:
                 printk(KERN_WARNING "Invalid NAND_ECC_MODE %d\n",
-                       this->eccmode);
-                BUG();
-        }
-
-        /*
-         * Check hardware ecc function availability and adjust number of ecc
-         * bytes per calculation step
-         */
-        switch (this->eccmode) {
-        case NAND_ECC_HW12_2048:
-                this->eccbytes += 4;
-        case NAND_ECC_HW8_512:
-                this->eccbytes += 2;
-        case NAND_ECC_HW6_512:
-                this->eccbytes += 3;
-        case NAND_ECC_HW3_512:
-        case NAND_ECC_HW3_256:
-                if (this->calculate_ecc && this->correct_data &&
-                    this->enable_hwecc)
-                        break;
-                printk(KERN_WARNING "No ECC functions supplied, "
-                       "Hardware ECC not possible\n");
+                       this->ecc.mode);
                 BUG();
         }
 
-        mtd->eccsize = this->eccsize;
-
         /*
          * Set the number of read / write steps for one page depending on ECC
          * mode
          */
-        switch (this->eccmode) {
-        case NAND_ECC_HW12_2048:
-                this->eccsteps = mtd->oobblock / 2048;
-                break;
-        case NAND_ECC_HW3_512:
-        case NAND_ECC_HW6_512:
-        case NAND_ECC_HW8_512:
-                this->eccsteps = mtd->oobblock / 512;
-                break;
-        case NAND_ECC_HW3_256:
-        case NAND_ECC_SOFT:
-                this->eccsteps = mtd->oobblock / 256;
-                break;
-
-        case NAND_ECC_NONE:
-                this->eccsteps = 1;
-                break;
+        this->ecc.steps = mtd->oobblock / this->ecc.size;
+        if(this->ecc.steps * this->ecc.size != mtd->oobblock) {
+                printk(KERN_WARNING "Invalid ecc parameters\n");
+                BUG();
         }
 
         /* Initialize state, waitqueue and spinlock */