[MTD] Refactor NAND hwcontrol to cmd_ctrl

The hwcontrol function enforced a step by step state machine
for any kind of hardware chip access. Let the hardware driver
know which control bits are set and inform it about a change
of the control lines. Let the hardware driver write out the
command and address bytes directly. This gives a peformance
advantage for address bus controlled chips and simplifies the
quirks in the hardware drivers.

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

1 files changed, 29 insertions, 48 deletions

diff --git a/drivers/mtd/nand/diskonchip.c b/drivers/mtd/nand/diskonchip.c
index f77298f3af60..e4bb6b429f87 100644
--- a/drivers/mtd/nand/diskonchip.c
+++ b/drivers/mtd/nand/diskonchip.c
@@ -95,7 +95,8 @@ static u_char empty_write_ecc[6] = { 0x4b, 0x00, 0xe2, 0x0e, 0x93, 0xf7 };
 #define DoC_is_Millennium(doc) ((doc)->ChipID == DOC_ChipID_DocMil)
 #define DoC_is_2000(doc) ((doc)->ChipID == DOC_ChipID_Doc2k)
 
-static void doc200x_hwcontrol(struct mtd_info *mtd, int cmd);
+static void doc200x_hwcontrol(struct mtd_info *mtd, int cmd,
+                              unsigned int bitmask);
 static void doc200x_select_chip(struct mtd_info *mtd, int chip);
 
 static int debug = 0;
@@ -402,12 +403,10 @@ static uint16_t __init doc200x_ident_chip(struct mtd_info *mtd, int nr)
         uint16_t ret;
 
         doc200x_select_chip(mtd, nr);
-        doc200x_hwcontrol(mtd, NAND_CTL_SETCLE);
-        this->write_byte(mtd, NAND_CMD_READID);
-        doc200x_hwcontrol(mtd, NAND_CTL_CLRCLE);
-        doc200x_hwcontrol(mtd, NAND_CTL_SETALE);
-        this->write_byte(mtd, 0);
-        doc200x_hwcontrol(mtd, NAND_CTL_CLRALE);
+        doc200x_hwcontrol(mtd, NAND_CMD_READID,
+                          NAND_CTRL_CLE | NAND_CTRL_CHANGE);
+        doc200x_hwcontrol(mtd, 0, NAND_CTRL_ALE | NAND_CTRL_CHANGE);
+        doc200x_hwcontrol(mtd, NAND_CMD_NONE, NAND_NCE | NAND_CTRL_CHANGE);
 
         /* We cant' use dev_ready here, but at least we wait for the
          * command to complete
@@ -425,12 +424,11 @@ static uint16_t __init doc200x_ident_chip(struct mtd_info *mtd, int nr)
                 } ident;
                 void __iomem *docptr = doc->virtadr;
 
-                doc200x_hwcontrol(mtd, NAND_CTL_SETCLE);
-                doc2000_write_byte(mtd, NAND_CMD_READID);
-                doc200x_hwcontrol(mtd, NAND_CTL_CLRCLE);
-                doc200x_hwcontrol(mtd, NAND_CTL_SETALE);
-                doc2000_write_byte(mtd, 0);
-                doc200x_hwcontrol(mtd, NAND_CTL_CLRALE);
+                doc200x_hwcontrol(mtd, NAND_CMD_READID,
+                                  NAND_CTRL_CLE | NAND_CTRL_CHANGE);
+                doc200x_hwcontrol(mtd, 0, NAND_CTRL_ALE | NAND_CTRL_CHANGE);
+                doc200x_hwcontrol(mtd, NAND_CMD_NONE,
+                                  NAND_NCE | NAND_CTRL_CHANGE);
 
                 udelay(50);
 
@@ -690,54 +688,37 @@ static void doc200x_select_chip(struct mtd_info *mtd, int chip)
         chip -= (floor * doc->chips_per_floor);
 
         /* 11.4.4 -- deassert CE before changing chip */
-        doc200x_hwcontrol(mtd, NAND_CTL_CLRNCE);
+        doc200x_hwcontrol(mtd, NAND_CMD_NONE, 0 | NAND_CTRL_CHANGE);
 
         WriteDOC(floor, docptr, FloorSelect);
         WriteDOC(chip, docptr, CDSNDeviceSelect);
 
-        doc200x_hwcontrol(mtd, NAND_CTL_SETNCE);
+        doc200x_hwcontrol(mtd, NAND_CMD_NONE, NAND_NCE | NAND_CTRL_CHANGE);
 
         doc->curchip = chip;
         doc->curfloor = floor;
 }
 
-static void doc200x_hwcontrol(struct mtd_info *mtd, int cmd)
+#define CDSN_CTRL_MSK (CDSN_CTRL_CE | CDSN_CTRL_CLE | CDSN_CTRL_ALE)
+
+static void doc200x_hwcontrol(struct mtd_info *mtd, int cmd,
+                              unsigned int ctrl)
 {
         struct nand_chip *this = mtd->priv;
         struct doc_priv *doc = this->priv;
         void __iomem *docptr = doc->virtadr;
 
-        switch (cmd) {
-        case NAND_CTL_SETNCE:
-                doc->CDSNControl |= CDSN_CTRL_CE;
-                break;
-        case NAND_CTL_CLRNCE:
-                doc->CDSNControl &= ~CDSN_CTRL_CE;
-                break;
-        case NAND_CTL_SETCLE:
-                doc->CDSNControl |= CDSN_CTRL_CLE;
-                break;
-        case NAND_CTL_CLRCLE:
-                doc->CDSNControl &= ~CDSN_CTRL_CLE;
-                break;
-        case NAND_CTL_SETALE:
-                doc->CDSNControl |= CDSN_CTRL_ALE;
-                break;
-        case NAND_CTL_CLRALE:
-                doc->CDSNControl &= ~CDSN_CTRL_ALE;
-                break;
-        case NAND_CTL_SETWP:
-                doc->CDSNControl |= CDSN_CTRL_WP;
-                break;
-        case NAND_CTL_CLRWP:
-                doc->CDSNControl &= ~CDSN_CTRL_WP;
-                break;
+        if (ctrl & NAND_CTRL_CHANGE) {
+                doc->CDSNControl &= ~CDSN_CTRL_MSK;
+                doc->CDSNControl |= ctrl & CDSN_CTRL_MSK;
+                if (debug)
+                        printk("hwcontrol(%d): %02x\n", cmd, doc->CDSNControl);
+                WriteDOC(doc->CDSNControl, docptr, CDSNControl);
+                /* 11.4.3 -- 4 NOPs after CSDNControl write */
+                DoC_Delay(doc, 4);
         }
-        if (debug)
-                printk("hwcontrol(%d): %02x\n", cmd, doc->CDSNControl);
-        WriteDOC(doc->CDSNControl, docptr, CDSNControl);
-        /* 11.4.3 -- 4 NOPs after CSDNControl write */
-        DoC_Delay(doc, 4);
+        if (cmd != NAND_CMD_NONE)
+                this->write_byte(mtd, cmd);
 }
 
 static void doc2001plus_command(struct mtd_info *mtd, unsigned command, int column, int page_addr)
@@ -1510,7 +1491,7 @@ static inline int __init doc2001plus_init(struct mtd_info *mtd)
         this->read_buf = doc2001plus_readbuf;
         this->verify_buf = doc2001plus_verifybuf;
         this->scan_bbt = inftl_scan_bbt;
-        this->hwcontrol = NULL;
+        this->cmd_ctrl = NULL;
         this->select_chip = doc2001plus_select_chip;
         this->cmdfunc = doc2001plus_command;
         this->ecc.hwctl = doc2001plus_enable_hwecc;
@@ -1670,7 +1651,7 @@ static int __init doc_probe(unsigned long physadr)
 
         nand->priv              = doc;
         nand->select_chip       = doc200x_select_chip;
-        nand->hwcontrol         = doc200x_hwcontrol;
+        nand->cmd_ctrl          = doc200x_hwcontrol;
         nand->dev_ready         = doc200x_dev_ready;
         nand->waitfunc          = doc200x_wait;
         nand->block_bad         = doc200x_block_bad;