piix/slc90e66: more tuneproc() fixing (take 2)

The tuneproc() method in both these drivers failed to set the drive's own speed.
Fix this by renaming the function and "wrapping around it" the new tuneproc()
method.  Switch back to calling tuneproc() in the PIO fallback code.
While at it, also convert the rest of the PIO timing code into proper C. :-)

Has been kind of tested on SLC90E66.  I'm too lazy to reboot my box and test
on ICH4... :-)

[ bart: I quickly tested it on ICH4. ]

Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/drivers/ide/pci/piix.c b/drivers/ide/pci/piix.c
index 569822f..061d300 100644
--- a/drivers/ide/pci/piix.c
+++ b/drivers/ide/pci/piix.c
@@ -1,10 +1,10 @@
 /*
- *  linux/drivers/ide/pci/piix.c	Version 0.46	December 3, 2006
+ *  linux/drivers/ide/pci/piix.c	Version 0.47	February 8, 2007
  *
  *  Copyright (C) 1998-1999 Andrzej Krzysztofowicz, Author and Maintainer
  *  Copyright (C) 1998-2000 Andre Hedrick <andre@linux-ide.org>
  *  Copyright (C) 2003 Red Hat Inc <alan@redhat.com>
- *  Copyright (C) 2006 MontaVista Software, Inc. <source@mvista.com>
+ *  Copyright (C) 2006-2007 MontaVista Software, Inc. <source@mvista.com>
  *
  *  May be copied or modified under the terms of the GNU General Public License
  *
@@ -205,14 +205,13 @@
 }
 
 /**
- *	piix_tune_drive		-	tune a drive attached to a PIIX
+ *	piix_tune_pio		-	tune PIIX for PIO mode
  *	@drive: drive to tune
  *	@pio: desired PIO mode
  *
- *	Set the interface PIO mode based upon  the settings done by AMI BIOS
- *	(might be useful if drive is not registered in CMOS for any reason).
+ *	Set the interface PIO mode based upon the settings done by AMI BIOS.
  */
-static void piix_tune_drive (ide_drive_t *drive, u8 pio)
+static void piix_tune_pio (ide_drive_t *drive, u8 pio)
 {
 	ide_hwif_t *hwif	= HWIF(drive);
 	struct pci_dev *dev	= hwif->pci_dev;
@@ -233,8 +232,6 @@
 					{ 2, 1 },
 					{ 2, 3 }, };
 
-	pio = ide_get_best_pio_mode(drive, pio, 4, NULL);
-
 	/*
 	 * Master vs slave is synchronized above us but the slave register is
 	 * shared by the two hwifs so the corner case of two slave timeouts in
@@ -253,19 +250,20 @@
 		master_data |=  0x4000;
 		master_data &= ~0x0070;
 		if (pio > 1) {
-			/* enable PPE, IE and TIME */
-			master_data = master_data | (control << 4);
+			/* Set PPE, IE and TIME */
+			master_data |= control << 4;
 		}
 		pci_read_config_byte(dev, slave_port, &slave_data);
-		slave_data = slave_data & (hwif->channel ? 0x0f : 0xf0);
-		slave_data = slave_data | (((timings[pio][0] << 2) | timings[pio][1]) << (hwif->channel ? 4 : 0));
+		slave_data &= hwif->channel ? 0x0f : 0xf0;
+		slave_data |= ((timings[pio][0] << 2) | timings[pio][1]) <<
+			       (hwif->channel ? 4 : 0);
 	} else {
 		master_data &= ~0x3307;
 		if (pio > 1) {
 			/* enable PPE, IE and TIME */
-			master_data = master_data | control;
+			master_data |= control;
 		}
-		master_data = master_data | (timings[pio][0] << 12) | (timings[pio][1] << 8);
+		master_data |= (timings[pio][0] << 12) | (timings[pio][1] << 8);
 	}
 	pci_write_config_word(dev, master_port, master_data);
 	if (is_slave)
@@ -274,6 +272,21 @@
 }
 
 /**
+ *	piix_tune_drive		-	tune a drive attached to PIIX
+ *	@drive: drive to tune
+ *	@pio: desired PIO mode
+ *
+ *	Set the drive's PIO mode (might be useful if drive is not registered
+ *	in CMOS for any reason).
+ */
+static void piix_tune_drive (ide_drive_t *drive, u8 pio)
+{
+	pio = ide_get_best_pio_mode(drive, pio, 4, NULL);
+	piix_tune_pio(drive, pio);
+	(void) ide_config_drive_speed(drive, XFER_PIO_0 + pio);
+}
+
+/**
  *	piix_tune_chipset	-	tune a PIIX interface
  *	@drive: IDE drive to tune
  *	@xferspeed: speed to configure
@@ -348,8 +361,8 @@
 			pci_write_config_byte(dev, 0x55, (u8) reg55 & ~w_flag);
 	}
 
-	piix_tune_drive(drive, piix_dma_2_pio(speed));
-	return (ide_config_drive_speed(drive, speed));
+	piix_tune_pio(drive, piix_dma_2_pio(speed));
+	return ide_config_drive_speed(drive, speed);
 }
 
 /**
@@ -392,9 +405,7 @@
 		return 0;
 
 	if (ide_use_fast_pio(drive))
-		/* Find best PIO mode. */
-		piix_tune_chipset(drive, XFER_PIO_0 +
-				  ide_get_best_pio_mode(drive, 255, 4, NULL));
+		piix_tune_drive(drive, 255);
 
 	return -1;
 }