From d4c477ca5448f19afaaf6c0cfd655009ea9e614d Mon Sep 17 00:00:00 2001 From: Brent Casavant Date: Tue, 21 Jun 2005 17:16:01 -0700 Subject: [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 Acked-by: Pat Gefre Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/serial/ioc4_serial.c | 31 ++++++++++++++++++------------- 1 file changed, 18 insertions(+), 13 deletions(-) (limited to 'drivers/serial') 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 */ -- cgit v1.2.3