[PATCH 2/2] Add Dell laptop driver

[Matthew Garrett <mjg59@srcf.ucam.org>]

This driver provides in-kernel control for the backlight and rfkill 
functionality on Dell laptops. It's based on the publically available 
information in the libsmbios package.

Signed-off-by: Matthew Garrett <mjg@redhat.com>

---

commit 472d8eed1891ba440f8e6ffde4787f6308390f7d
Author: Matthew Garrett <mjg59@m6300.(none)>
Date:   Sat Aug 16 21:12:51 2008 +0100

    Add Dell laptop driver

diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index a726f3b..c77eab3 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -475,4 +475,16 @@ config SGI_GRU_DEBUG
 	This option enables addition debugging code for the SGI GRU driver. If
 	you are unsure, say N.
 
+config DELL_LAPTOP
+        tristate "Dell Laptop Extras (EXPERIMENTAL)"
+        depends on X86
+        depends on DCDBAS
+	depends on EXPERIMENTAL
+	depends on BACKLIGHT_CLASS_DEVICE
+	depends on RFKILL
+	default n
+	---help---
+	This driver adds support for rfkill and backlight control to Dell
+	laptops.
+
 endif # MISC_DEVICES
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index c6c13f6..865343d 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -30,3 +30,4 @@ obj-$(CONFIG_KGDB_TESTS)	+= kgdbts.o
 obj-$(CONFIG_SGI_XP)		+= sgi-xp/
 obj-$(CONFIG_SGI_GRU)		+= sgi-gru/
 obj-$(CONFIG_HP_ILO)		+= hpilo.o
+obj-$(CONFIG_DELL_LAPTOP)	+= dell-laptop.o
\ No newline at end of file
diff --git a/drivers/misc/dell-laptop.c b/drivers/misc/dell-laptop.c
new file mode 100644
index 0000000..ab09a69
--- /dev/null
+++ b/drivers/misc/dell-laptop.c
@@ -0,0 +1,356 @@
+/*
+ *  Driver for Dell laptop extras
+ *
+ *  Copyright (c) Red Hat <mjg@redhat.com>
+ *
+ *  Based on documentation in the libsmbios package, Copyright (C) 2005 Dell
+ *  Inc.
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2 as
+ *  published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/backlight.h>
+#include <linux/err.h>
+#include <linux/dmi.h>
+#include <linux/io.h>
+#include <linux/rfkill.h>
+#include "../firmware/dcdbas.h"
+
+struct calling_interface_buffer {
+	u16 class;
+	u16 select;
+	volatile u32 input[4];
+	volatile u32 output[4];
+} __attribute__ ((packed));
+
+struct calling_interface_token {
+	u16 tokenID;
+	u16 location;
+	union {
+		u16 value;
+		u16 stringlength;
+	};
+};
+
+struct calling_interface_structure {
+	u8 type;
+	u8 length;
+	u16 handle;
+	u16 cmdIOAddress;
+	u8 cmdIOCode;
+	u32 supportedCmds;
+	struct calling_interface_token tokens[];
+} __attribute__ ((packed));
+
+static int da_command_address;
+static int da_command_code;
+static int da_num_tokens;
+static struct calling_interface_token *da_tokens;
+
+static struct backlight_device *dell_backlight_device;
+static struct rfkill *wifi_rfkill;
+static struct rfkill *bluetooth_rfkill;
+static struct rfkill *wwan_rfkill;
+
+static struct dmi_system_id __initdata dell_device_table[] = {
+	{
+		.ident = "Dell laptop",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
+			DMI_MATCH(DMI_CHASSIS_TYPE, "8"),
+		},
+	},
+	{ }
+};
+
+static void parse_da_table(const struct dmi_header *dm)
+{
+	/* Final token is a terminator, so we don't want to copy it */
+	int tokens = (dm->length-11)/sizeof(struct calling_interface_token)-1;
+	struct calling_interface_structure *table =
+		(struct calling_interface_structure *)dm;
+
+	/* 4 bytes of table header, plus 7 bytes of Dell header, plus at least
+	   6 bytes of entry */
+
+	if (dm->length < 17)
+		return;
+
+	da_command_address = table->cmdIOAddress;
+	da_command_code = table->cmdIOCode;
+
+	da_tokens = krealloc(da_tokens, (da_num_tokens + tokens) *
+			     sizeof(struct calling_interface_token),
+			     GFP_KERNEL);
+
+	memcpy(da_tokens+da_num_tokens, table->tokens,
+	       sizeof(struct calling_interface_token) * tokens);
+
+	da_num_tokens += tokens;
+}
+
+static void find_tokens(const struct dmi_header *dm)
+{
+	switch (dm->type) {
+	case 0xd4: /* Indexed IO */
+		break;
+	case 0xd5: /* Protected Area Type 1 */
+		break;
+	case 0xd6: /* Protected Area Type 2 */
+		break;
+	case 0xda: /* Calling interface */
+		parse_da_table(dm);
+		break;
+	}
+}
+
+static int find_token_location(int tokenid)
+{
+	int i;
+	for (i = 0; i < da_num_tokens; i++) {
+		if (da_tokens[i].tokenID == tokenid)
+			return da_tokens[i].location;
+	}
+	return -1;
+}
+
+static struct calling_interface_buffer *dell_send_request(
+	struct calling_interface_buffer *buffer, int class, int select)
+{
+	struct smi_cmd *command = kzalloc(sizeof(struct smi_cmd), GFP_KERNEL);
+	command->magic = SMI_CMD_MAGIC;
+	command->command_address = da_command_address;
+	command->command_code = da_command_code;
+	command->ebx = virt_to_phys(buffer);
+	command->ecx = 0x42534931;
+
+	buffer->class = class;
+	buffer->select = select;
+
+	dcdbas_smi_request(command);
+
+	kfree(command);
+
+	return buffer;
+}
+
+static int dell_rfkill_set(int radio, enum rfkill_state state)
+{
+	struct calling_interface_buffer *buffer =
+		kzalloc(sizeof(struct calling_interface_buffer), GFP_KERNEL);
+	int disable = (state == RFKILL_STATE_UNBLOCKED) ? 0 : 1;
+	buffer->input[0] = (1 | (radio<<8) | (disable << 16));
+	dell_send_request(buffer, 17, 11);
+	kfree(buffer);
+	return 0;
+}
+
+static int dell_wifi_set(void *data, enum rfkill_state state)
+{
+	return dell_rfkill_set(1, state);
+}
+
+static int dell_bluetooth_set(void *data, enum rfkill_state state)
+{
+	return dell_rfkill_set(2, state);
+}
+
+static int dell_wwan_set(void *data, enum rfkill_state state)
+{
+	return dell_rfkill_set(3, state);
+}
+
+static int dell_rfkill_get(int bit, enum rfkill_state *state)
+{
+	struct calling_interface_buffer *buffer =
+		kzalloc(sizeof(struct calling_interface_buffer), GFP_KERNEL);
+	int status;
+	int new_state = RFKILL_STATE_HARD_BLOCKED;
+
+	dell_send_request(buffer, 17, 11);
+	status = buffer->output[1];
+
+	if (status & (1<<16))
+		new_state = RFKILL_STATE_SOFT_BLOCKED;
+
+	if (status & (1<<bit))
+		*state = new_state;
+	else
+		*state = RFKILL_STATE_UNBLOCKED;
+
+	kfree(buffer);
+
+	return 0;
+}
+
+static int dell_wifi_get(void *data, enum rfkill_state *state)
+{
+	return dell_rfkill_get(17, state);
+}
+
+static int dell_bluetooth_get(void *data, enum rfkill_state *state)
+{
+	return dell_rfkill_get(18, state);
+}
+
+static int dell_wwan_get(void *data, enum rfkill_state *state)
+{
+	return dell_rfkill_get(19, state);
+}
+
+static void dell_setup_rfkill(void)
+{
+	struct calling_interface_buffer *buffer =
+		kzalloc(sizeof(struct calling_interface_buffer), GFP_KERNEL);
+	int status;
+
+	dell_send_request(buffer, 17, 11);
+	status = buffer->output[1];
+
+	if ((status & (1<<2|1<<8)) == (1<<2|1<<8)) {
+		wifi_rfkill = rfkill_allocate(NULL, RFKILL_TYPE_WLAN);
+		wifi_rfkill->name = "dell-wifi";
+		wifi_rfkill->toggle_radio = dell_wifi_set;
+		wifi_rfkill->get_state = dell_wifi_get;
+		rfkill_register(wifi_rfkill);
+	}
+
+	if ((status & (1<<3|1<<9)) == (1<<3|1<<9)) {
+		bluetooth_rfkill = rfkill_allocate(NULL, RFKILL_TYPE_BLUETOOTH);
+		bluetooth_rfkill->name = "dell-bluetooth";
+		bluetooth_rfkill->toggle_radio = dell_bluetooth_set;
+		bluetooth_rfkill->get_state = dell_bluetooth_get;
+		rfkill_register(bluetooth_rfkill);
+	}
+
+	if ((status & (1<<4|1<<10)) == (1<<4|1<<10)) {
+		wwan_rfkill = rfkill_allocate(NULL, RFKILL_TYPE_WWAN);
+		wwan_rfkill->name = "dell-wwan";
+		wwan_rfkill->toggle_radio = dell_wwan_set;
+		wwan_rfkill->get_state = dell_wwan_get;
+		rfkill_register(wwan_rfkill);
+	}
+
+	kfree(buffer);
+}
+
+static int dell_send_intensity(struct backlight_device *bd)
+{
+	int intensity = bd->props.brightness;
+	struct calling_interface_buffer *buffer =
+		kzalloc(sizeof(struct calling_interface_buffer), GFP_KERNEL);
+
+	buffer->input[0] = find_token_location(0x7d);
+	buffer->input[1] = intensity;
+
+	if (buffer->input[0] == -1) {
+		kfree(buffer);
+		return -ENODEV;
+	}
+
+	dell_send_request(buffer, 1, 1);
+	dell_send_request(buffer, 1, 2);
+
+	kfree(buffer);
+
+	return 0;
+}
+
+static int dell_get_intensity(struct backlight_device *bd)
+{
+	struct calling_interface_buffer *buffer =
+		kzalloc(sizeof(struct calling_interface_buffer), GFP_KERNEL);
+	int brightness;
+
+	buffer->input[0] = find_token_location(0x7d);
+
+	if (buffer->input[0] == -1) {
+		kfree(buffer);
+		return -ENODEV;
+	}
+
+	dell_send_request(buffer, 0, 1);
+
+	brightness = buffer->output[1];
+
+	kfree(buffer);
+
+	return brightness;
+}
+
+static struct backlight_ops dell_ops = {
+	.get_brightness = dell_get_intensity,
+	.update_status  = dell_send_intensity,
+};
+
+static int __init dell_init(void)
+{
+	struct calling_interface_buffer *buffer;
+	int max_intensity = 0;
+
+	if (!dmi_check_system(dell_device_table))
+		return -ENODEV;
+
+	dmi_walk(find_tokens);
+
+	if (!da_tokens)
+		return -ENODEV;
+
+	buffer = kzalloc(sizeof(struct calling_interface_buffer), GFP_KERNEL);
+	buffer->input[0] = find_token_location(0x7d);
+
+	if (buffer->input[0] != -1) {
+		dell_send_request(buffer, 2, 1);
+		max_intensity = buffer->output[3];
+	}
+
+	kfree(buffer);
+
+	if (max_intensity) {
+		dell_backlight_device = backlight_device_register(
+			"dell_backlight",
+			NULL, NULL,
+			&dell_ops);
+
+		if (IS_ERR(dell_backlight_device)) {
+			dell_backlight_device = NULL;
+			goto out;
+		}
+
+		dell_backlight_device->props.max_brightness = max_intensity;
+		dell_backlight_device->props.brightness =
+			dell_get_intensity(dell_backlight_device);
+		backlight_update_status(dell_backlight_device);
+	}
+
+	dell_setup_rfkill();
+
+out:
+	return 0;
+}
+
+static void __exit dell_exit(void)
+{
+	if (dell_backlight_device)
+		backlight_device_unregister(dell_backlight_device);
+	if (wifi_rfkill)
+		rfkill_unregister(wifi_rfkill);
+	if (bluetooth_rfkill)
+		rfkill_unregister(bluetooth_rfkill);
+	if (wwan_rfkill)
+		rfkill_unregister(wwan_rfkill);
+}
+
+module_init(dell_init);
+module_exit(dell_exit);
+
+MODULE_AUTHOR("Matthew Garrett <mjg@redhat.com>");
+MODULE_DESCRIPTION("Dell laptop driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("dmi:*svnDellInc.:*:ct8:*");

-- 
Matthew Garrett | mjg59@srcf.ucam.org