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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: Ryan Bradetich <rbrad@parisc-linux.org> Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
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752b940359
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6142544584
1 changed files with 31 additions and 11 deletions
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@ -70,7 +70,35 @@ static struct timer_list mux_timer;
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#define UART_PUT_CHAR(p, c) __raw_writel((c), (p)->membase + IO_DATA_REG_OFFSET)
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#define UART_GET_FIFO_CNT(p) __raw_readl((p)->membase + IO_DCOUNT_REG_OFFSET)
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#define GET_MUX_PORTS(iodc_data) ((((iodc_data)[4] & 0xf0) >> 4) * 8) + 8
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/**
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* get_mux_port_count - Get the number of available ports on the Mux.
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* @dev: The parisc device.
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*
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* This function is used to determine the number of ports the Mux
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* supports. The IODC data reports the number of ports the Mux
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* can support, but there are cases where not all the Mux ports
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* are connected. This function can override the IODC and
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* return the true port count.
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*/
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static int __init get_mux_port_count(struct parisc_device *dev)
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{
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u8 iodc_data[32];
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unsigned long bytecnt;
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int status = pdc_iodc_read(&bytecnt, dev->hpa.start, 0, iodc_data, 32);
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BUG_ON(status != PDC_OK);
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/* If this is the built-in Mux for the K-Class (Eole CAP/MUX),
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* we only need to allocate resources for 1 port since the
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* other 7 ports are not connected.
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*/
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if(((iodc_data[0] << 4) | ((iodc_data[1] & 0xf0) >> 4)) == 0x15)
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return 1;
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/* Return the number of ports specified in the iodc data. */
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return ((((iodc_data)[4] & 0xf0) >> 4) * 8) + 8;
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}
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/**
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* mux_tx_empty - Check if the transmitter fifo is empty.
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@ -442,17 +470,9 @@ static struct uart_ops mux_pops = {
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*/
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static int __init mux_probe(struct parisc_device *dev)
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{
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int i, status, port_count;
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u8 iodc_data[32];
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unsigned long bytecnt;
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int i, status;
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status = pdc_iodc_read(&bytecnt, dev->hpa.start, 0, iodc_data, 32);
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if(status != PDC_OK) {
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printk(KERN_ERR "Serial mux: Unable to read IODC.\n");
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return 1;
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}
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port_count = GET_MUX_PORTS(iodc_data);
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int port_count = get_mux_port_count(dev);
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printk(KERN_INFO "Serial mux driver (%d ports) Revision: 0.6\n", port_count);
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dev_set_drvdata(&dev->dev, (void *)(long)port_count);
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