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Commit 61425445 authored by Ryan Bradetich's avatar Ryan Bradetich Committed by Kyle McMartin
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[PARISC] [MUX] Correctly report the number of available ports 



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: default avatarRyan Bradetich <rbrad@parisc-linux.org>
Signed-off-by: default avatarKyle McMartin <kyle@parisc-linux.org>
parent 752b9403

drivers/serial/mux.c

+31 −11
Original line number Diff line number Diff line
@@ -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);