[Linux-parport] [PATCH 2.6.7] Parallel port detection via ACPI

[Dino Klein]

Hi,
I've modified the parport_pc.c file to detect parallel ports via ACPI; it is 
partially a cut & paste from the serial port (8250) acpi code. It's kinda 
crude, but it works. It utilizes the ACPI subsystem to get the resources 
assigned to the port, and then passes them on to the detection routine. I've 
verified that it is working on my machine by cycling between the modes in 
the BIOS (spp, epp, ecp+epp), and observing proper detection in the logs.
I commented out the pnp & non-pci detection calls, since ACPI replaces them. 
I also disabled the SuperIO detection, since it was grabbing the parallel 
port before the ACPI detection kicked in on my motherboard with a via686 
southbridge.
Again, this is is kinda of crude, but I would really like to see some 
parallel port detection via ACPI, so I won't have to manually specify irq & 
dma. Perhaps there should be an option to choose between PnP and ACPI, since 
there shouldn't be a reason to use both.

--- linux-2.6.7-orig/drivers/parport/parport_pc.c	2004-06-18 
14:20:00.000000000 -0400
+++ linux-2.6.7/drivers/parport/parport_pc.c	2004-06-18 13:05:01.000000000 
-0400
@@ -55,6 +55,9 @@
#include <linux/pci.h>
#include <linux/pnp.h>
#include <linux/sysctl.h>
+#include <linux/acpi.h>
+
+#include <acpi/acpi_bus.h>

#include <asm/io.h>
#include <asm/dma.h>
@@ -101,6 +104,7 @@
#endif
static int pci_registered_parport;
static int pnp_registered_parport;
+static int acpi_registered_parport;

/* frob_control, but for ECR */
static void frob_econtrol (struct parport *pb, unsigned char m,
@@ -2917,6 +2921,92 @@
};


+/* A stuct to help with resource allocation enumeration */
+struct parport_pc_resources
+{
+	int	io_lo;
+	int	io_hi;
+	int	irq;
+	int	dma;
+};
+
+
+
+/* Callback to process all the assigned resources to the parallel port 
device */
+static acpi_status acpi_parport_pc_resource(struct acpi_resource *res, void 
*data)
+{
+	struct parport_pc_resources *pcres = (struct parport_pc_resources *) data;
+	acpi_status status;
+
+
+	if (res->id == ACPI_RSTYPE_IO)
+	{
+		struct acpi_resource_io *io = (struct acpi_resource_io *) &res->data.io;
+		if (pcres->io_lo==0) pcres->io_lo = io->min_base_address;
+		else pcres->io_hi = io->min_base_address;
+	}
+	else if (res->id == ACPI_RSTYPE_IRQ)
+	{
+		struct acpi_resource_irq *irq = (struct acpi_resource_irq *) 
&res->data.irq;
+		pcres->irq = irq->interrupts[0];
+	}
+	else if (res->id == ACPI_RSTYPE_DMA)
+	{
+		struct acpi_resource_dma *dma = (struct acpi_resource_dma *) 
&res->data.dma;
+		pcres->dma = dma->channels[0];
+	}
+
+	return AE_OK;
+}
+
+
+static int acpi_parport_pc_add(struct acpi_device *device)
+{
+	acpi_status status;
+	struct parport_pc_resources pcres;
+	struct parport *pdata;
+
+
+	pcres.io_lo = 0;
+	pcres.io_hi = 0;
+	pcres.irq = PARPORT_IRQ_NONE;
+	pcres.dma = PARPORT_DMA_NONE;
+
+	status = acpi_walk_resources(device->handle, METHOD_NAME__CRS,
+				     acpi_parport_pc_resource, &pcres);
+	if (ACPI_FAILURE(status))
+		return -ENODEV;
+
+	printk("ACPI parport device with low IO 0x%X, high IO 0x%X, IRQ %d, DMA 
%d\n", pcres.io_lo, pcres.io_hi, pcres.irq, pcres.dma);
+	if (!(pdata = parport_pc_probe_port (pcres.io_lo, pcres.io_hi, pcres.irq, 
pcres.dma, NULL)))
+	{
+		printk("probe of ACPI parport device failed\n");
+		return -ENODEV;
+	}
+
+	acpi_driver_data(device) = pdata;
+	return 0;
+}
+
+static int acpi_parport_pc_remove(struct acpi_device *device, int type)
+{
+	struct parport *pdata = (struct parport *)acpi_driver_data(device);
+	parport_pc_unregister_port(pdata);
+	return 0;
+}
+
+
+static struct acpi_driver parport_pc_acpi_driver = {
+	.name =		"parport_pc",
+	.class =	"",
+	.ids =		"PNP0400, PNP0401",
+	.ops =	{
+		.add =		acpi_parport_pc_add,
+		.remove =	acpi_parport_pc_remove,
+	},
+};
+
+
/* This is called by parport_pc_find_nonpci_ports (in asm/parport.h) */
static int __init __attribute__((unused))
parport_pc_find_isa_ports (int autoirq, int autodma)
@@ -2953,9 +3043,12 @@
#endif

	/* Onboard SuperIO chipsets that show themselves on the PCI bus. */
+	/*
	count += parport_pc_init_superio (autoirq, autodma);
+	*/

	/* PnP ports, skip detection if SuperIO already found them */
+	/*
	if (!count) {
		r = pnp_register_driver (&parport_pc_pnp_driver);
		if (r >= 0) {
@@ -2963,9 +3056,12 @@
			count += r;
		}
	}
+	*/

	/* ISA ports and whatever (see asm/parport.h). */
+	/*
	count += parport_pc_find_nonpci_ports (autoirq, autodma);
+	*/

	r = pci_register_driver (&parport_pc_pci_driver);
	if (r >= 0) {
@@ -2973,6 +3069,13 @@
		count += r;
	}

+	r = acpi_bus_register_driver (&parport_pc_acpi_driver);
+	if (ACPI_SUCCESS(r))
+	{
+		acpi_registered_parport = 1;
+		/* should we increase count? */
+	}
+
	return count;
}

@@ -3190,6 +3293,8 @@
		pci_unregister_driver (&parport_pc_pci_driver);
	if (pnp_registered_parport)
		pnp_unregister_driver (&parport_pc_pnp_driver);
+	if (acpi_registered_parport)
+		acpi_bus_unregister_driver(&parport_pc_acpi_driver);

	spin_lock(&ports_lock);
	while (!list_empty(&ports_list)) {

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