mtd: nand: Wait tCCS after a column change

[mirror_ubuntu-zesty-kernel.git] / drivers / mtd / nand / nand_base.c

diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index a74d9e4bd8b2ad3db2b776d942b8e294f917a056..0acb0070280a9090700347b54cb9ec9e16c4cb6e 100644 (file)
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -709,6 +709,25 @@ static void nand_command(struct mtd_info *mtd, unsigned int command,
        nand_wait_ready(mtd);
 }
 
+static void nand_ccs_delay(struct nand_chip *chip)
+{
+       /*
+        * The controller already takes care of waiting for tCCS when the RNDIN
+        * or RNDOUT command is sent, return directly.
+        */
+       if (!(chip->options & NAND_WAIT_TCCS))
+               return;
+
+       /*
+        * Wait tCCS_min if it is correctly defined, otherwise wait 500ns
+        * (which should be safe for all NANDs).
+        */
+       if (chip->data_interface && chip->data_interface->timings.sdr.tCCS_min)
+               ndelay(chip->data_interface->timings.sdr.tCCS_min / 1000);
+       else
+               ndelay(500);
+}
+
 /**
  * nand_command_lp - [DEFAULT] Send command to NAND large page device
  * @mtd: MTD device structure
@@ -745,7 +764,10 @@ static void nand_command_lp(struct mtd_info *mtd, unsigned int command,
                                column >>= 1;
                        chip->cmd_ctrl(mtd, column, ctrl);
                        ctrl &= ~NAND_CTRL_CHANGE;
-                       chip->cmd_ctrl(mtd, column >> 8, ctrl);
+
+                       /* Only output a single addr cycle for 8bits opcodes. */
+                       if (!nand_opcode_8bits(command))
+                               chip->cmd_ctrl(mtd, column >> 8, ctrl);
                }
                if (page_addr != -1) {
                        chip->cmd_ctrl(mtd, page_addr, ctrl);
@@ -770,10 +792,13 @@ static void nand_command_lp(struct mtd_info *mtd, unsigned int command,
        case NAND_CMD_ERASE1:
        case NAND_CMD_ERASE2:
        case NAND_CMD_SEQIN:
-       case NAND_CMD_RNDIN:
        case NAND_CMD_STATUS:
                return;
 
+       case NAND_CMD_RNDIN:
+               nand_ccs_delay(chip);
+               return;
+
        case NAND_CMD_RESET:
                if (chip->dev_ready)
                        break;
@@ -792,6 +817,8 @@ static void nand_command_lp(struct mtd_info *mtd, unsigned int command,
                               NAND_NCE | NAND_CLE | NAND_CTRL_CHANGE);
                chip->cmd_ctrl(mtd, NAND_CMD_NONE,
                               NAND_NCE | NAND_CTRL_CHANGE);
+
+               nand_ccs_delay(chip);
                return;
 
        case NAND_CMD_READ0:
@@ -4796,19 +4823,15 @@ int nand_scan(struct mtd_info *mtd, int maxchips)
 EXPORT_SYMBOL(nand_scan);
 
 /**
- * nand_release - [NAND Interface] Free resources held by the NAND device
- * @mtd: MTD device structure
+ * nand_cleanup - [NAND Interface] Free resources held by the NAND device
+ * @chip: NAND chip object
  */
-void nand_release(struct mtd_info *mtd)
+void nand_cleanup(struct nand_chip *chip)
 {
-       struct nand_chip *chip = mtd_to_nand(mtd);
-
        if (chip->ecc.mode == NAND_ECC_SOFT &&
            chip->ecc.algo == NAND_ECC_BCH)
                nand_bch_free((struct nand_bch_control *)chip->ecc.priv);
 
-       mtd_device_unregister(mtd);
-
        nand_release_data_interface(chip);
 
        /* Free bad block table memory */
@@ -4821,6 +4844,18 @@ void nand_release(struct mtd_info *mtd)
                        & NAND_BBT_DYNAMICSTRUCT)
                kfree(chip->badblock_pattern);
 }
+EXPORT_SYMBOL_GPL(nand_cleanup);
+
+/**
+ * nand_release - [NAND Interface] Unregister the MTD device and free resources
+ *               held by the NAND device
+ * @mtd: MTD device structure
+ */
+void nand_release(struct mtd_info *mtd)
+{
+       mtd_device_unregister(mtd);
+       nand_cleanup(mtd_to_nand(mtd));
+}
 EXPORT_SYMBOL_GPL(nand_release);
 
 MODULE_LICENSE("GPL");