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[PARISC] [MUX] Correctly report the number of available ports

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This patch adds a new function to return the actual number
of ports available.  Some of the built-in Muxes return the
number of supported ports, but not all of these port are
available for use.

Signed-off-by: Ryan Bradetich <rbrad@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
This commit is contained in:
Ryan Bradetich 2006-11-10 03:08:45 +00:00 committed by Kyle McMartin
parent 752b940359
commit 6142544584
1 changed files with 31 additions and 11 deletions
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42
drivers/serial/mux.c
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@ -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;
int i, status;
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;
}
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);