Re: [ACPI] A GPE block driver

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On Sat, Nov 06, 2004 at 06:44:42AM +0000, Matthew Wilcox wrote:
> I have a GPE block driver (PNP ID ACPI0006) almost written.  I have
> a couple of questions though ...
> 
> 1. Given an acpi_device, how do I get an acpi_namespace_node?
> 2. Where does gpe_block_base_number come from?  Is that the _UID?

Never mind.  I was using the wrong interface.  Here's the driver.
I can't actually test it until someone goes into the server room to push
a button on the machine.

I do suspect there to be a problem though.  I get the message:
GSI 120 (level, low) -> CPU 3 (0x0c02) vector 63
but there is no entry in /proc/interrupts for vector 63.  I think the
right thing to do would be to add a request_irq() somewhere in the
acpi_install_gpe_block() call path.  FADT GPE blocks don't need this --
they use the sci_irq.  But other blocks can use their own IRQ.

Index: linux-2.6/drivers/acpi/Kconfig
===================================================================
RCS file: /var/cvs/linux-2.6/drivers/acpi/Kconfig,v
retrieving revision 1.13
diff -u -p -r1.13 Kconfig

--- linux-2.6/drivers/acpi/Kconfig	11 Oct 2004 21:41:01 -0000	1.13
+++ linux-2.6/drivers/acpi/Kconfig	6 Nov 2004 07:39:03 -0000
@@ -119,6 +119,15 @@ config ACPI_FAN
 	  This driver adds support for ACPI fan devices, allowing user-mode 
 	  applications to perform basic fan control (on, off, status).
 
+config ACPI_GPE_BLOCK
+	tristate "GPE block"
+	depends on ACPI_INTERPRETER
+	depends on !IA64_SGI_SN
+	default m
+	help
+	  GPE block devices are used to increase the number of interrupts
+	  available on larger machines.
+
 config ACPI_PROCESSOR
 	tristate "Processor"
 	depends on ACPI_INTERPRETER
Index: linux-2.6/drivers/acpi/Makefile
===================================================================
RCS file: /var/cvs/linux-2.6/drivers/acpi/Makefile,v
retrieving revision 1.4
diff -u -p -r1.4 Makefile
--- linux-2.6/drivers/acpi/Makefile	13 Sep 2004 15:22:51 -0000	1.4
+++ linux-2.6/drivers/acpi/Makefile	6 Nov 2004 07:39:03 -0000
@@ -38,6 +38,7 @@ obj-$(CONFIG_ACPI_BATTERY)	+= battery.o
 obj-$(CONFIG_ACPI_BUTTON)	+= button.o
 obj-$(CONFIG_ACPI_EC)		+= ec.o
 obj-$(CONFIG_ACPI_FAN)		+= fan.o
+obj-$(CONFIG_ACPI_GPE_BLOCK)	+= gpe-block.o
 obj-$(CONFIG_ACPI_PCI)		+= pci_root.o pci_link.o pci_irq.o pci_bind.o
 obj-$(CONFIG_ACPI_POWER)	+= power.o
 obj-$(CONFIG_ACPI_PROCESSOR)	+= processor.o
Index: linux-2.6/drivers/acpi/gpe-block.c
===================================================================
RCS file: linux-2.6/drivers/acpi/gpe-block.c
diff -N linux-2.6/drivers/acpi/gpe-block.c
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ linux-2.6/drivers/acpi/gpe-block.c	6 Nov 2004 07:39:03 -0000
@@ -0,0 +1,110 @@
+/*
+ * drivers/acpi/gpe-block.c
+ *
+ * Copyright (c) Matthew Wilcox for Hewlett Packard 2004
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or (at
+ * your option) any later version.
+ */
+
+#include <linux/module.h>
+#include <acpi/acpi_bus.h>
+#include <acpi/acpi_drivers.h>
+#include <acpi/acevents.h>
+
+MODULE_AUTHOR("Matthew Wilcox <wi...@hp...>");
+MODULE_LICENSE("GPL");
+
+struct gpe_block {
+	struct acpi_generic_address address;
+	u32 register_count;
+	u8 gpe_block_base_number;
+	u32 interrupt_level;
+};
+
+static acpi_status acpi_gpe_block_crs_irq(struct acpi_resource_ext_irq *irq,
+		struct gpe_block *data)
+{
+	data->interrupt_level = acpi_register_gsi(irq->interrupts[0],
+			irq->edge_level, irq->active_high_low);
+	return AE_OK;
+}
+
+static acpi_status acpi_gpe_block_crs_addr(struct acpi_resource_address64 *addr,
+		struct gpe_block *data)
+{
+	if (addr->resource_type == ACPI_MEMORY_RANGE) {
+		data->address.address_space_id = ACPI_ADR_SPACE_SYSTEM_MEMORY;
+	} else if (addr->resource_type == ACPI_IO_RANGE) {
+		data->address.address_space_id = ACPI_ADR_SPACE_SYSTEM_IO;
+	} else {
+		return AE_CTRL_TERMINATE;
+	}
+
+	data->address.register_bit_width = ACPI_GPE_REGISTER_WIDTH;
+	data->address.register_bit_offset = ACPI_GPE_REGISTER_WIDTH;
+	data->address.address = addr->min_address_range;
+	data->register_count = (addr->max_address_range - addr->min_address_range) / (ACPI_GPE_REGISTER_WIDTH * 2);
+
+	return AE_OK;
+}
+
+static acpi_status acpi_gpe_block_crs_add(struct acpi_resource *res, void *data)
+{
+	if (res->id == ACPI_RSTYPE_EXT_IRQ)
+		return acpi_gpe_block_crs_irq(&res->data.extended_irq, data);
+
+	if (res->id == ACPI_RSTYPE_ADDRESS16 ||
+	    res->id == ACPI_RSTYPE_ADDRESS32 ||
+	    res->id == ACPI_RSTYPE_ADDRESS64) {
+		struct acpi_resource_address64 address;
+		acpi_resource_to_address64(res, &address);
+		return acpi_gpe_block_crs_addr(&address, data);
+	}
+
+	return AE_OK;
+}
+
+static int acpi_gpe_block_add(struct acpi_device *device)
+{
+	struct gpe_block block;
+
+	block.register_count = 0;
+	acpi_walk_resources(device->handle, METHOD_NAME__CRS,
+			acpi_gpe_block_crs_add, &block);
+	if (block.register_count == 0)
+		return 0;
+
+	return acpi_install_gpe_block(device->handle, &block.address,
+			block.register_count, block.interrupt_level);
+}
+
+static int acpi_gpe_block_remove(struct acpi_device *device, int type)
+{
+	return acpi_remove_gpe_block(device->handle);
+}
+
+static struct acpi_driver acpi_gpe_block_driver = {
+	.name =		"gpe-block",
+	.ids =		"ACPI0006",
+	.ops =	{
+		.add =		acpi_gpe_block_add,
+		.remove =	acpi_gpe_block_remove,
+	},
+};
+
+static int __init acpi_gpe_block_init(void)
+{
+	int result = acpi_bus_register_driver(&acpi_gpe_block_driver);
+	return (result < 0) ? -ENODEV : 0;
+}
+
+static void __exit acpi_gpe_block_exit(void)
+{
+	acpi_bus_unregister_driver(&acpi_gpe_block_driver);
+}
+
+module_init(acpi_gpe_block_init);
+module_exit(acpi_gpe_block_exit);

-- 
"Next the statesmen will invent cheap lies, putting the blame upon 
the nation that is attacked, and every man will be glad of those
conscience-soothing falsities, and will diligently study them, and refuse
to examine any refutations of them; and thus he will by and by convince 
himself that the war is just, and will thank God for the better sleep 
he enjoys after this process of grotesque self-deception." -- Mark Twain


