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authorBrent Casavant <bcasavan@sgi.com>2005-06-21 17:16:01 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-06-21 18:46:32 -0700
commitd4c477ca5448f19afaaf6c0cfd655009ea9e614d (patch)
tree75571ad144ff904afbd39b1b24766461255396ac /drivers/serial/ioc4_serial.c
parente5d310b349b2cbcc0dab31139c92201f332695bb (diff)
downloadlinux-d4c477ca5448f19afaaf6c0cfd655009ea9e614d.tar.bz2
[PATCH] ioc4: PCI bus speed detection
Several hardware features of SGI's IOC4 I/O controller chip require timing-related driver calculations dependent upon the PCI bus speed. This patch enables the core IOC4 driver code to detect the actual bus speed and store a value that can later be used by the IOC4 subdrivers as needed. Signed-off-by: Brent Casavant <bcasavan@sgi.com> Acked-by: Pat Gefre <pfg@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'drivers/serial/ioc4_serial.c')
-rw-r--r--drivers/serial/ioc4_serial.c31
1 files changed, 18 insertions, 13 deletions
diff --git a/drivers/serial/ioc4_serial.c b/drivers/serial/ioc4_serial.c
index da5f10eb4845..793c3a7cbe47 100644
--- a/drivers/serial/ioc4_serial.c
+++ b/drivers/serial/ioc4_serial.c
@@ -299,7 +299,6 @@ struct ioc4_serial {
} ioc4_serial;
/* UART clock speed */
-#define IOC4_SER_XIN_CLK IOC4_SER_XIN_CLK_66
#define IOC4_SER_XIN_CLK_66 66666667
#define IOC4_SER_XIN_CLK_33 33333333
@@ -1012,21 +1011,20 @@ static irqreturn_t ioc4_intr(int irq, void *arg, struct pt_regs *regs)
* ioc4_attach_local - Device initialization.
* Called at *_attach() time for each
* IOC4 with serial ports in the system.
- * @control: ioc4_control ptr
- * @pdev: PCI handle for this device
- * @soft: soft struct for this device
- * @ioc4: ioc4 mem space
+ * @idd: Master module data for this IOC4
*/
-static int inline ioc4_attach_local(struct pci_dev *pdev,
- struct ioc4_control *control,
- struct ioc4_soft *soft, void __iomem *ioc4_misc,
- void __iomem *ioc4_serial)
+static int inline ioc4_attach_local(struct ioc4_driver_data *idd)
{
struct ioc4_port *port;
struct ioc4_port *ports[IOC4_NUM_SERIAL_PORTS];
int port_number;
uint16_t ioc4_revid_min = 62;
uint16_t ioc4_revid;
+ struct pci_dev *pdev = idd->idd_pdev;
+ struct ioc4_control* control = idd->idd_serial_data;
+ struct ioc4_soft *soft = control->ic_soft;
+ void __iomem *ioc4_misc = idd->idd_misc_regs;
+ void __iomem *ioc4_serial = soft->is_ioc4_serial_addr;
/* IOC4 firmware must be at least rev 62 */
pci_read_config_word(pdev, PCI_COMMAND_SPECIAL, &ioc4_revid);
@@ -1063,7 +1061,15 @@ static int inline ioc4_attach_local(struct pci_dev *pdev,
port->ip_ioc4_soft = soft;
port->ip_pdev = pdev;
port->ip_ienb = 0;
- port->ip_pci_bus_speed = IOC4_SER_XIN_CLK;
+ /* Use baud rate calculations based on detected PCI
+ * bus speed. Simply test whether the PCI clock is
+ * running closer to 66MHz or 33MHz.
+ */
+ if (idd->count_period/IOC4_EXTINT_COUNT_DIVISOR < 20) {
+ port->ip_pci_bus_speed = IOC4_SER_XIN_CLK_66;
+ } else {
+ port->ip_pci_bus_speed = IOC4_SER_XIN_CLK_33;
+ }
port->ip_baud = 9600;
port->ip_control = control;
port->ip_mem = ioc4_misc;
@@ -2733,9 +2739,8 @@ ioc4_serial_attach_one(struct ioc4_driver_data *idd)
"%s : request_irq fails for IRQ 0x%x\n ",
__FUNCTION__, idd->idd_pdev->irq);
}
- if ((ret = ioc4_attach_local(idd->idd_pdev, control, soft,
- soft->is_ioc4_misc_addr,
- soft->is_ioc4_serial_addr)))
+ ret = ioc4_attach_local(idd);
+ if (ret)
goto out4;
/* register port with the serial core */