mtd: nand: split ONFI detection logic to its own function

In order to reduce the indentation and improve the readability of nand_get_
flash_type, split the ONFI detection logic to its own function. The detection
logic inside nand_flash_detect_onfi is also rewritten to allow for less
indentation.

Signed-off-by: Florian Fainelli <ffainelli@freebox.fr>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 5b26fffc353475f2405f6d0c3dfb083e8d95e6fa..5b96f621f7c96bf14bfff5b7b10c898cc21e74a4 100644 (file)
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -2818,6 +2818,72 @@ static u16 onfi_crc16(u16 crc, u8 const *p, size_t len)
        return crc;
 }
 
+/*
+ * Check if the NAND chip is ONFI compliant, returns 1 if it is, 0 otherwise
+ */
+static int nand_flash_detect_onfi(struct mtd_info *mtd, struct nand_chip *chip,
+                                       int busw)
+{
+       struct nand_onfi_params *p = &chip->onfi_params;
+       int i;
+       int val;
+
+       /* try ONFI for unknow chip or LP */
+       chip->cmdfunc(mtd, NAND_CMD_READID, 0x20, -1);
+       if (chip->read_byte(mtd) != 'O' || chip->read_byte(mtd) != 'N' ||
+               chip->read_byte(mtd) != 'F' || chip->read_byte(mtd) != 'I')
+               return 0;
+
+       printk(KERN_INFO "ONFI flash detected\n");
+       chip->cmdfunc(mtd, NAND_CMD_PARAM, 0, -1);
+       for (i = 0; i < 3; i++) {
+               chip->read_buf(mtd, (uint8_t *)p, sizeof(*p));
+               if (onfi_crc16(ONFI_CRC_BASE, (uint8_t *)p, 254) ==
+                               le16_to_cpu(p->crc)) {
+                       printk(KERN_INFO "ONFI param page %d valid\n", i);
+                       break;
+               }
+       }
+
+       if (i == 3)
+               return 0;
+
+       /* check version */
+       val = le16_to_cpu(p->revision);
+       if (val == 1 || val > (1 << 4)) {
+               printk(KERN_INFO "%s: unsupported ONFI version: %d\n",
+                                                               __func__, val);
+               return 0;
+       }
+
+       if (val & (1 << 4))
+               chip->onfi_version = 22;
+       else if (val & (1 << 3))
+               chip->onfi_version = 21;
+       else if (val & (1 << 2))
+               chip->onfi_version = 20;
+       else
+               chip->onfi_version = 10;
+
+       sanitize_string(p->manufacturer, sizeof(p->manufacturer));
+       sanitize_string(p->model, sizeof(p->model));
+       if (!mtd->name)
+               mtd->name = p->model;
+       mtd->writesize = le32_to_cpu(p->byte_per_page);
+       mtd->erasesize = le32_to_cpu(p->pages_per_block) * mtd->writesize;
+       mtd->oobsize = le16_to_cpu(p->spare_bytes_per_page);
+       chip->chipsize = le32_to_cpu(p->blocks_per_lun) * mtd->erasesize;
+       busw = 0;
+       if (le16_to_cpu(p->features) & 1)
+               busw = NAND_BUSWIDTH_16;
+
+       chip->options &= ~NAND_CHIPOPTIONS_MSK;
+       chip->options |= (NAND_NO_READRDY |
+                       NAND_NO_AUTOINCR) & NAND_CHIPOPTIONS_MSK;
+
+       return 1;
+}
+
 /*
  * Get the flash and manufacturer id and lookup if the type is supported
  */
@@ -2828,6 +2894,7 @@ static struct nand_flash_dev *nand_get_flash_type(struct mtd_info *mtd,
 {
        int i, maf_idx;
        u8 id_data[8];
+       int ret;
 
        /* Select the device */
        chip->select_chip(mtd, 0);
@@ -2872,67 +2939,10 @@ static struct nand_flash_dev *nand_get_flash_type(struct mtd_info *mtd,
 
        chip->onfi_version = 0;
        if (!type->name || !type->pagesize) {
-               /* try ONFI for unknow chip or LP */
-               chip->cmdfunc(mtd, NAND_CMD_READID, 0x20, -1);
-               if (chip->read_byte(mtd) == 'O' &&
-                       chip->read_byte(mtd) == 'N' &&
-                       chip->read_byte(mtd) == 'F' &&
-                       chip->read_byte(mtd) == 'I') {
-
-                       struct nand_onfi_params *p = &chip->onfi_params;
-                       int i;
-
-                       printk(KERN_INFO "ONFI flash detected\n");
-                       chip->cmdfunc(mtd, NAND_CMD_PARAM, 0, -1);
-                       for (i = 0; i < 3; i++) {
-                               chip->read_buf(mtd, (uint8_t *)p, sizeof(*p));
-                               if (onfi_crc16(ONFI_CRC_BASE, (uint8_t *)p, 254) ==
-                                                               le16_to_cpu(p->crc))
-                               {
-                                        printk(KERN_INFO "ONFI param page %d valid\n", i);
-                                        break;
-                               }
-                       }
-
-                       if (i < 3) {
-                               /* check version */
-                               int val = le16_to_cpu(p->revision);
-                               if (val == 1 || val > (1 << 4))
-                                       printk(KERN_INFO "%s: unsupported ONFI version: %d\n",
-                                               __func__, val);
-                               else {
-                                       if (val & (1 << 4))
-                                               chip->onfi_version = 22;
-                                       else if (val & (1 << 3))
-                                               chip->onfi_version = 21;
-                                       else if (val & (1 << 2))
-                                               chip->onfi_version = 20;
-                                       else
-                                               chip->onfi_version = 10;
-                               }
-                       }
-
-                       if (chip->onfi_version) {
-                               sanitize_string(p->manufacturer, sizeof(p->manufacturer));
-                               sanitize_string(p->model, sizeof(p->model));
-                               if (!mtd->name)
-                                       mtd->name = p->model;
-                               mtd->writesize = le32_to_cpu(p->byte_per_page);
-                               mtd->erasesize = le32_to_cpu(p->pages_per_block)*mtd->writesize;
-                               mtd->oobsize = le16_to_cpu(p->spare_bytes_per_page);
-                               chip->chipsize = le32_to_cpu(p->blocks_per_lun) * mtd->erasesize;
-                               busw = 0;
-                               if (le16_to_cpu(p->features) & 1)
-                                       busw = NAND_BUSWIDTH_16;
-
-                               chip->options &= ~NAND_CHIPOPTIONS_MSK;
-                               chip->options |= (NAND_NO_READRDY |
-                                               NAND_NO_AUTOINCR) & NAND_CHIPOPTIONS_MSK;
-
-                               goto ident_done;
-
-                       }
-               }
+               /* Check is chip is ONFI compliant */
+               ret = nand_flash_detect_onfi(mtd, chip, busw);
+               if (ret)
+                       goto ident_done;
        }
 
        chip->cmdfunc(mtd, NAND_CMD_READID, 0x00, -1);