aboutsummaryrefslogtreecommitdiff
path: root/arch/sh/drivers/pci/common.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/sh/drivers/pci/common.c')
-rw-r--r--arch/sh/drivers/pci/common.c64
1 files changed, 64 insertions, 0 deletions
diff --git a/arch/sh/drivers/pci/common.c b/arch/sh/drivers/pci/common.c
new file mode 100644
index 00000000000..f67c946a861
--- /dev/null
+++ b/arch/sh/drivers/pci/common.c
@@ -0,0 +1,64 @@
+#include <linux/pci.h>
+#include <linux/kernel.h>
+
+static int __init
+early_read_config_word(struct pci_channel *hose,
+ int top_bus, int bus, int devfn, int offset, u16 *value)
+{
+ struct pci_dev fake_dev;
+ struct pci_bus fake_bus;
+
+ fake_dev.bus = &fake_bus;
+ fake_dev.sysdata = hose;
+ fake_dev.devfn = devfn;
+ fake_bus.number = bus;
+ fake_bus.sysdata = hose;
+ fake_bus.ops = hose->pci_ops;
+
+ if (bus != top_bus)
+ /* Fake a parent bus structure. */
+ fake_bus.parent = &fake_bus;
+ else
+ fake_bus.parent = NULL;
+
+ return pci_read_config_word(&fake_dev, offset, value);
+}
+
+int __init pci_is_66mhz_capable(struct pci_channel *hose,
+ int top_bus, int current_bus)
+{
+ u32 pci_devfn;
+ unsigned short vid;
+ int cap66 = -1;
+ u16 stat;
+
+ printk(KERN_INFO "PCI: Checking 66MHz capabilities...\n");
+
+ for (pci_devfn = 0; pci_devfn < 0xff; pci_devfn++) {
+ if (PCI_FUNC(pci_devfn))
+ continue;
+ if (early_read_config_word(hose, top_bus, current_bus,
+ pci_devfn, PCI_VENDOR_ID, &vid) !=
+ PCIBIOS_SUCCESSFUL)
+ continue;
+ if (vid == 0xffff)
+ continue;
+
+ /* check 66MHz capability */
+ if (cap66 < 0)
+ cap66 = 1;
+ if (cap66) {
+ early_read_config_word(hose, top_bus, current_bus,
+ pci_devfn, PCI_STATUS, &stat);
+ if (!(stat & PCI_STATUS_66MHZ)) {
+ printk(KERN_DEBUG
+ "PCI: %02x:%02x not 66MHz capable.\n",
+ current_bus, pci_devfn);
+ cap66 = 0;
+ break;
+ }
+ }
+ }
+
+ return cap66 > 0;
+}