diff options
| -rw-r--r-- | drivers/serial/mux.c | 42 |
1 files changed, 31 insertions, 11 deletions
diff --git a/drivers/serial/mux.c b/drivers/serial/mux.c index 87269cca9c7c..f5b17f5333fb 100644 --- a/drivers/serial/mux.c +++ b/drivers/serial/mux.c @@ -70,7 +70,35 @@ static struct timer_list mux_timer; #define UART_PUT_CHAR(p, c) __raw_writel((c), (p)->membase + IO_DATA_REG_OFFSET) #define UART_GET_FIFO_CNT(p) __raw_readl((p)->membase + IO_DCOUNT_REG_OFFSET) -#define GET_MUX_PORTS(iodc_data) ((((iodc_data)[4] & 0xf0) >> 4) * 8) + 8 + +/** + * get_mux_port_count - Get the number of available ports on the Mux. + * @dev: The parisc device. + * + * This function is used to determine the number of ports the Mux + * supports. The IODC data reports the number of ports the Mux + * can support, but there are cases where not all the Mux ports + * are connected. This function can override the IODC and + * return the true port count. + */ +static int __init get_mux_port_count(struct parisc_device *dev) +{ + u8 iodc_data[32]; + unsigned long bytecnt; + + int status = pdc_iodc_read(&bytecnt, dev->hpa.start, 0, iodc_data, 32); + BUG_ON(status != PDC_OK); + + /* If this is the built-in Mux for the K-Class (Eole CAP/MUX), + * we only need to allocate resources for 1 port since the + * other 7 ports are not connected. + */ + if(((iodc_data[0] << 4) | ((iodc_data[1] & 0xf0) >> 4)) == 0x15) + return 1; + + /* Return the number of ports specified in the iodc data. */ + return ((((iodc_data)[4] & 0xf0) >> 4) * 8) + 8; +} /** * mux_tx_empty - Check if the transmitter fifo is empty. @@ -442,17 +470,9 @@ static struct uart_ops mux_pops = { */ static int __init mux_probe(struct parisc_device *dev) { - int i, status, port_count; - u8 iodc_data[32]; - unsigned long bytecnt; - - status = pdc_iodc_read(&bytecnt, dev->hpa.start, 0, iodc_data, 32); - if(status != PDC_OK) { - printk(KERN_ERR "Serial mux: Unable to read IODC.\n"); - return 1; - } + int i, status; - port_count = GET_MUX_PORTS(iodc_data); + int port_count = get_mux_port_count(dev); printk(KERN_INFO "Serial mux driver (%d ports) Revision: 0.6\n", port_count); dev_set_drvdata(&dev->dev, (void *)(long)port_count); |