[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, 17 insertions, 10 deletions

diff --git a/drivers/mtd/nand/spia.c b/drivers/mtd/nand/spia.c
index 9737f1d67c3c..1f6d429b1583 100644
--- a/drivers/mtd/nand/spia.c
+++ b/drivers/mtd/nand/spia.c
@@ -82,20 +82,27 @@ static const struct mtd_partition partition_info[] = {
 
 /*
  *      hardware specific access to control-lines
-*/
+ *
+ *      ctrl:
+ *      NAND_CNE: bit 0 -> bit 2
+ *      NAND_CLE: bit 1 -> bit 0
+ *      NAND_ALE: bit 2 -> bit 1
+ */
 static void spia_hwcontrol(struct mtd_info *mtd, int cmd)
 {
-        switch (cmd) {
+        struct nand_chip *chip = mtd->priv;
 
-        case NAND_CTL_SETCLE: (*(volatile unsigned char *) (spia_io_base + spia_pedr)) |=  0x01; break;
-        case NAND_CTL_CLRCLE: (*(volatile unsigned char *) (spia_io_base + spia_pedr)) &= ~0x01; break;
+        if (ctrl & NAND_CTRL_CHANGE) {
+                void __iomem *addr = spia_io_base + spia_pedr;
+                unsigned char bits;
 
-        case NAND_CTL_SETALE: (*(volatile unsigned char *) (spia_io_base + spia_pedr)) |=  0x02; break;
-        case NAND_CTL_CLRALE: (*(volatile unsigned char *) (spia_io_base + spia_pedr)) &= ~0x02; break;
-
-        case NAND_CTL_SETNCE: (*(volatile unsigned char *) (spia_io_base + spia_pedr)) &= ~0x04; break;
-        case NAND_CTL_CLRNCE: (*(volatile unsigned char *) (spia_io_base + spia_pedr)) |=  0x04; break;
+                bits = (ctrl & NAND_CNE) << 2;
+                bits |= (ctrl & NAND_CLE | NAND_ALE) >> 1;
+                writeb((readb(addr) & ~0x7) | bits, addr);
         }
+
+        if (cmd != NAND_CMD_NONE)
+                writeb(cmd, chip->IO_ADDR_W);
 }
 
 /*
@@ -133,7 +140,7 @@ static int __init spia_init(void)
         this->IO_ADDR_R = (void __iomem *)spia_fio_base;
         this->IO_ADDR_W = (void __iomem *)spia_fio_base;
         /* Set address of hardware control function */
-        this->hwcontrol = spia_hwcontrol;
+        this->cmd_ctrl = spia_hwcontrol;
         /* 15 us command delay time */
         this->chip_delay = 15;