Commit 26c068da authored by Sergei Shtylyov's avatar Sergei Shtylyov Committed by Linus Torvalds

[PATCH] ide: HPT3xx: fix PCI clock detection

Use the f_CNT value saved by the HighPoint BIOS if available as reading it
directly would give us a wrong PCI frequency after DPLL has already been
calibrated by BIOS.
Signed-off-by: default avatarSergei Shtylyov <sshtylyov@ru.mvista.com>
Cc: Bartlomiej Zolnierkiewicz <B.Zolnierkiewicz@elka.pw.edu.pl>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 73d1dd93
......@@ -70,6 +70,8 @@
* - fix/remove bad/unused timing tables and use one set of tables for the whole
* 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
* - 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
......@@ -1010,8 +1012,8 @@ static void __devinit hpt37x_clocking(ide_hwif_t *hwif)
struct hpt_info *info = ide_get_hwifdata(hwif);
struct pci_dev *dev = hwif->pci_dev;
int adjust, i;
u16 freq;
u32 pll;
u16 freq = 0;
u32 pll, temp = 0;
u8 reg5bh = 0, mcr1 = 0;
/*
......@@ -1025,15 +1027,34 @@ static void __devinit hpt37x_clocking(ide_hwif_t *hwif)
pci_write_config_byte(dev, 0x5b, 0x23);
/*
* set up the PLL. we need to adjust it so that it's stable.
* freq = Tpll * 192 / Tpci
* We'll have to read f_CNT value in order to determine
* the PCI clock frequency according to the following ratio:
*
* Todo. For non x86 should probably check the dword is
* set to 0xABCDExxx indicating the BIOS saved f_CNT
* f_CNT = Fpci * 192 / Fdpll
*
* 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).
* 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...
*/
pci_read_config_word(dev, 0x78, &freq);
freq &= 0x1FF;
pci_read_config_dword(dev, 0x70, &temp);
if ((temp & 0xFFFFF000) != 0xABCDE000) {
int i;
printk(KERN_WARNING "HPT37X: no clock data saved by BIOS\n");
/* Calculate the average value of f_CNT */
for (temp = i = 0; i < 128; i++) {
pci_read_config_word(dev, 0x78, &freq);
temp += freq & 0x1ff;
mdelay(1);
}
freq = temp / 128;
} else
freq = temp & 0x1ff;
/*
* HPT3xxN chips use different PCI clock information.
* Currently we always set up the PLL for them.
......@@ -1095,11 +1116,8 @@ static void __devinit hpt37x_clocking(ide_hwif_t *hwif)
info->flags |= PLL_MODE;
/*
* FIXME: make this work correctly, esp with 372N as per
* reference driver code.
*
* adjust PLL based upon PCI clock, enable it, and wait for
* stabilization.
* Adjust the PLL based upon the PCI clock, enable it, and
* wait for stabilization...
*/
adjust = 0;
freq = (pll < F_LOW_PCI_50) ? 2 : 4;
......
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