[patch] PNP SMCf010 quirk: auto-config device if BIOS left it broken

Some HP firmware leaves the SMCf010 IRDA device incompletely configured,
or reports the wrong resources in _CRS.  As a workaround, when we find
such a device, try to auto-configure the device.

This ignores the _CRS data, picks a config from _PRS, and runs _SRS to
configure the device.  This makes smsc-ircc2 work correctly with PNP
resources on HP nx5000 and nc8000/nw8000 system.

I think Windows does something like this by default for all devices,
so we might want to consider doing the same thing in Linux.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>

Index: w/drivers/pnp/quirks.c
===================================================================
--- w.orig/drivers/pnp/quirks.c	2007-06-14 15:08:45.000000000 -0600
+++ w/drivers/pnp/quirks.c	2007-06-14 15:09:56.000000000 -0600
@@ -107,31 +107,61 @@
 	return;
 }
 
-static void quirk_smc_enable(struct pnp_dev *dev)
+static int quirk_smc_fir_enabled(struct pnp_dev *dev)
 {
-	unsigned int firbase;
+	unsigned long firbase;
+	u8 bank, high, low, chip;
+
+	if (!pnp_port_valid(dev, 1))
+		return 0;
+
+	firbase = pnp_port_start(dev, 1);
 
-	if (!dev->active || !pnp_port_valid(dev, 1))
+	/* Select register bank 3 */
+	bank = inb(firbase + 7);
+	bank &= 0xf0;
+	bank |= 3;
+	outb(bank, firbase + 7);
+
+	high = inb(firbase + 0);
+	low  = inb(firbase + 1);
+	chip = inb(firbase + 2);
+
+	/* This corresponds to the check in smsc_ircc_present() */
+	if (high == 0x10 && low == 0xb8 && (chip == 0xf1 || chip == 0xf2))
+		return 1;
+
+	return 0;
+}
+
+static void quirk_smc_enable(struct pnp_dev *dev)
+{
+	/*
+	 * If the BIOS left the device disabled, or it is enabled and
+	 * responding correctly, we're in good shape.
+	 */
+	if (!dev->active || quirk_smc_fir_enabled(dev))
 		return;
 
 	/*
-	 * On the HP/Compaq nw8240 (and probably other similar machines),
-	 * there is an SMCF010 device with two I/O port regions:
-	 *
-	 *	0x3e8-0x3ef SIR
-	 *	0x100-0x10f FIR
+	 * Sometimes the BIOS claims the device is enabled, but it reports
+	 * the wrong FIR resources or doesn't properly configure ISA or LPC
+	 * bridges on the way to the device.
 	 *
-	 * _STA reports the device is enabled, but in fact, the BIOS
-	 * neglects to enable the FIR range.  Fortunately, it does fully
-	 * enable the device if we call _SRS.
+	 * HP nc6000 and nc8000/nw8000 laptops have known problems like
+	 * this.  Fortunately, they do fix things up if we auto-configure
+	 * the device using its _PRS and _SRS methods.
 	 */
-	firbase = pnp_port_start(dev, 1);
-	if (inb(firbase + 0x7 /* IRCC_MASTER */) == 0xff) {
-		pnp_err("%s (%s) enabled but not responding, disabling and "
-			"re-enabling", dev->dev.bus_id, pnp_dev_name(dev));
-		pnp_disable_dev(dev);
-		pnp_activate_dev(dev);
-	}
+	dev_err(&dev->dev, "%s device not responding, auto-configuring "
+		"resources\n", dev->id->id);
+
+	pnp_disable_dev(dev);
+	pnp_init_resource_table(&dev->res);
+	pnp_auto_config_dev(dev);
+	pnp_activate_dev(dev);
+
+	if (!quirk_smc_fir_enabled(dev))
+		dev_err(&dev->dev, "giving up; try \"smsc-ircc2.nopnp\"\n");
 }