hpt366: fix PCI clock detection for HPT374 (take 4)

HPT374 BIOS seems to only save f_CNT register value for the function #0 before
re-tuning DPLL (that causes the driver to report obviously distorted f_CNT for
the function #1) -- fix this by always reading the saved f_CNT register value
from the function #0 in the driver's init_chipset() method.
While at it, introduce 'chip_type' for holding the 'struct hpt_info' field
of the same name and replace the structure assignment with memcpy()...

Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

drivers/ide/pci/hpt366.c

@@ -1,5 +1,5 @@
 /*
- * linux/drivers/ide/pci/hpt366.c		Version 1.10	Jun 29, 2007
+ * linux/drivers/ide/pci/hpt366.c		Version 1.11	Aug 11, 2007
  *
  * Copyright (C) 1999-2003		Andre Hedrick <andre@linux-ide.org>
  * Portions Copyright (C) 2001	        Sun Microsystems, Inc.
@@ -68,7 +68,8 @@
  *   HPT37x chip family; save space by introducing the separate transfer mode
  *   table in which the mode lookup is done
  * - use f_CNT value saved by  the HighPoint BIOS as reading it directly gives
- *   the wrong PCI frequency since DPLL has already been calibrated by BIOS
+ *   the wrong PCI frequency since DPLL has already been calibrated by BIOS;
+ *   read it only from the function 0 of HPT374 chips
  * - fix the hotswap code:  it caused RESET- to glitch when tristating the bus,
  *   and for HPT36x the obsolete HDIO_TRISTATE_HWIF handler was called instead
  * - pass to init_chipset() handlers a copy of the IDE PCI device structure as
@@ -981,6 +982,7 @@ static unsigned int __devinit init_chipset_hpt366(struct pci_dev *dev, const cha
 	struct hpt_info *info	= kmalloc(sizeof(struct hpt_info), GFP_KERNEL);
 	unsigned long io_base	= pci_resource_start(dev, 4);
 	u8 pci_clk,  dpll_clk	= 0;	/* PCI and DPLL clock in MHz */
+	u8 chip_type;
 	enum ata_clock	clock;
 
 	if (info == NULL) {
@@ -992,7 +994,8 @@ static unsigned int __devinit init_chipset_hpt366(struct pci_dev *dev, const cha
 	 * Copy everything from a static "template" structure
 	 * to just allocated per-chip hpt_info structure.
 	 */
-	*info = *(struct hpt_info *)pci_get_drvdata(dev);
+	memcpy(info, pci_get_drvdata(dev), sizeof(struct hpt_info));
+	chip_type = info->chip_type;
 
 	pci_write_config_byte(dev, PCI_CACHE_LINE_SIZE, (L1_CACHE_BYTES / 4));
 	pci_write_config_byte(dev, PCI_LATENCY_TIMER, 0x78);
@@ -1002,7 +1005,7 @@ static unsigned int __devinit init_chipset_hpt366(struct pci_dev *dev, const cha
 	/*
 	 * First, try to estimate the PCI clock frequency...
 	 */
-	if (info->chip_type >= HPT370) {
+	if (chip_type >= HPT370) {
 		u8  scr1  = 0;
 		u16 f_cnt = 0;
 		u32 temp  = 0;
@@ -1016,7 +1019,7 @@ static unsigned int __devinit init_chipset_hpt366(struct pci_dev *dev, const cha
 		 * HighPoint does this for HPT372A.
 		 * NOTE: This register is only writeable via I/O space.
 		 */
-		if (info->chip_type == HPT372A)
+		if (chip_type == HPT372A)
 			outb(0x0e, io_base + 0x9c);
 
 		/*
@@ -1034,13 +1037,28 @@ static unsigned int __devinit init_chipset_hpt366(struct pci_dev *dev, const cha
 		 * First try reading the register in which the HighPoint BIOS
 		 * saves f_CNT value before  reprogramming the DPLL from its
 		 * default setting (which differs for the various chips).
-		 * NOTE: This register is only accessible via I/O space.
 		 *
-		 * In case the signature check fails, we'll have to resort to
-		 * reading the f_CNT register itself in hopes that nobody has
-		 * touched the DPLL yet...
+		 * NOTE: This register is only accessible via I/O space;
+		 * HPT374 BIOS only saves it for the function 0, so we have to
+		 * always read it from there -- no need to check the result of
+		 * pci_get_slot() for the function 0 as the whole device has
+		 * been already "pinned" (via function 1) in init_setup_hpt374()
+		 */
+		if (chip_type == HPT374 && (PCI_FUNC(dev->devfn) & 1)) {
+			struct pci_dev	*dev1 = pci_get_slot(dev->bus,
+							     dev->devfn - 1);
+			unsigned long io_base = pci_resource_start(dev1, 4);
+
+			temp =	inl(io_base + 0x90);
+			pci_dev_put(dev1);
+		} else
+			temp =	inl(io_base + 0x90);
+
+		/*
+		 * In case the signature check fails, we'll have to
+		 * resort to reading the f_CNT register itself in hopes
+		 * that nobody has touched the DPLL yet...
 		 */
-		temp = inl(io_base + 0x90);
 		if ((temp & 0xFFFFF000) != 0xABCDE000) {
 			int i;
 
@@ -1120,7 +1138,7 @@ static unsigned int __devinit init_chipset_hpt366(struct pci_dev *dev, const cha
 	 * We also  don't like using  the DPLL because this causes glitches
 	 * on PRST-/SRST- when the state engine gets reset...
 	 */
-	if (info->chip_type >= HPT374 || info->settings[clock] == NULL) {
+	if (chip_type >= HPT374 || info->settings[clock] == NULL) {
 		u16 f_low, delta = pci_clk < 50 ? 2 : 4;
 		int adjust;
 
@@ -1190,7 +1208,7 @@ static unsigned int __devinit init_chipset_hpt366(struct pci_dev *dev, const cha
 	/* Point to this chip's own instance of the hpt_info structure. */
 	pci_set_drvdata(dev, info);
 
-	if (info->chip_type >= HPT370) {
+	if (chip_type >= HPT370) {
 		u8  mcr1, mcr4;
 
 		/*
@@ -1209,7 +1227,7 @@ static unsigned int __devinit init_chipset_hpt366(struct pci_dev *dev, const cha
 	 * the MISC. register to stretch the UltraDMA Tss timing.
 	 * NOTE: This register is only writeable via I/O space.
 	 */
-	if (info->chip_type == HPT371N && clock == ATA_CLOCK_66MHZ)
+	if (chip_type == HPT371N && clock == ATA_CLOCK_66MHZ)
 
 		outb(inb(io_base + 0x9c) | 0x04, io_base + 0x9c);