HID: i2c-hid: Reorganize so ACPI and OF are separate modules

This patch rejiggers the i2c-hid code so that the OF (Open Firmware
aka Device Tree) and ACPI support is separated out a bit.  The OF and
ACPI drivers are now separate modules that wrap the core module.

Essentially, what we're doing here:
* Make "power up" and "power down" a function that can be (optionally)
  implemented by a given user of the i2c-hid core.
* The OF and ACPI modules are drivers on their own, so they implement
  probe / remove / suspend / resume / shutdown.  The core code
  provides implementations that OF and ACPI can call into.

We'll organize this so that we now have 3 modules: the old i2c-hid
module becomes the "core" module and two new modules will depend on
it, handling probing the specific device.

As part of this work, we'll remove the i2c-hid "platform data"
concept since it's not needed.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>

1 files changed, 143 insertions, 0 deletions

diff --git a/drivers/hid/i2c-hid/i2c-hid-acpi.c b/drivers/hid/i2c-hid/i2c-hid-acpi.c
new file mode 100644
index 000000000000..bb8c00e6be78
--- /dev/null
+++ b/drivers/hid/i2c-hid/i2c-hid-acpi.c
@@ -0,0 +1,143 @@
+/*
+ * HID over I2C ACPI Subclass
+ *
+ * Copyright (c) 2012 Benjamin Tissoires <benjamin.tissoires@gmail.com>
+ * Copyright (c) 2012 Ecole Nationale de l'Aviation Civile, France
+ * Copyright (c) 2012 Red Hat, Inc
+ *
+ * This code was forked out of the core code, which was partly based on
+ * "USB HID support for Linux":
+ *
+ *  Copyright (c) 1999 Andreas Gal
+ *  Copyright (c) 2000-2005 Vojtech Pavlik <vojtech@suse.cz>
+ *  Copyright (c) 2005 Michael Haboustak <mike-@cinci.rr.com> for Concept2, Inc
+ *  Copyright (c) 2007-2008 Oliver Neukum
+ *  Copyright (c) 2006-2010 Jiri Kosina
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file COPYING in the main directory of this archive for
+ * more details.
+ */
+
+#include <linux/acpi.h>
+#include <linux/device.h>
+#include <linux/i2c.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/pm.h>
+
+#include "i2c-hid.h"
+
+struct i2c_hid_acpi {
+	struct i2chid_ops ops;
+	struct i2c_client *client;
+};
+
+static const struct acpi_device_id i2c_hid_acpi_blacklist[] = {
+	/*
+	 * The CHPN0001 ACPI device, which is used to describe the Chipone
+	 * ICN8505 controller, has a _CID of PNP0C50 but is not HID compatible.
+	 */
+	{"CHPN0001", 0 },
+	{ },
+};
+
+static int i2c_hid_acpi_get_descriptor(struct i2c_client *client)
+{
+	static guid_t i2c_hid_guid =
+		GUID_INIT(0x3CDFF6F7, 0x4267, 0x4555,
+			  0xAD, 0x05, 0xB3, 0x0A, 0x3D, 0x89, 0x38, 0xDE);
+	union acpi_object *obj;
+	struct acpi_device *adev;
+	acpi_handle handle;
+	u16 hid_descriptor_address;
+
+	handle = ACPI_HANDLE(&client->dev);
+	if (!handle || acpi_bus_get_device(handle, &adev)) {
+		dev_err(&client->dev, "Error could not get ACPI device\n");
+		return -ENODEV;
+	}
+
+	if (acpi_match_device_ids(adev, i2c_hid_acpi_blacklist) == 0)
+		return -ENODEV;
+
+	obj = acpi_evaluate_dsm_typed(handle, &i2c_hid_guid, 1, 1, NULL,
+				      ACPI_TYPE_INTEGER);
+	if (!obj) {
+		dev_err(&client->dev, "Error _DSM call to get HID descriptor address failed\n");
+		return -ENODEV;
+	}
+
+	hid_descriptor_address = obj->integer.value;
+	ACPI_FREE(obj);
+
+	return hid_descriptor_address;
+}
+
+static void i2c_hid_acpi_shutdown_tail(struct i2chid_ops *ops)
+{
+	struct i2c_hid_acpi *ihid_acpi =
+		container_of(ops, struct i2c_hid_acpi, ops);
+	struct device *dev = &ihid_acpi->client->dev;
+	acpi_device_set_power(ACPI_COMPANION(dev), ACPI_STATE_D3_COLD);
+}
+
+static int i2c_hid_acpi_probe(struct i2c_client *client,
+			      const struct i2c_device_id *dev_id)
+{
+	struct device *dev = &client->dev;
+	struct i2c_hid_acpi *ihid_acpi;
+	struct acpi_device *adev;
+	u16 hid_descriptor_address;
+	int ret;
+
+	ihid_acpi = devm_kzalloc(&client->dev, sizeof(*ihid_acpi), GFP_KERNEL);
+	if (!ihid_acpi)
+		return -ENOMEM;
+
+	ihid_acpi->client = client;
+	ihid_acpi->ops.shutdown_tail = i2c_hid_acpi_shutdown_tail;
+
+	ret = i2c_hid_acpi_get_descriptor(client);
+	if (ret < 0)
+		return ret;
+	hid_descriptor_address = ret;
+
+	adev = ACPI_COMPANION(dev);
+	if (adev)
+		acpi_device_fix_up_power(adev);
+
+	if (acpi_gbl_FADT.flags & ACPI_FADT_LOW_POWER_S0) {
+		device_set_wakeup_capable(dev, true);
+		device_set_wakeup_enable(dev, false);
+	}
+
+	return i2c_hid_core_probe(client, &ihid_acpi->ops,
+				  hid_descriptor_address);
+}
+
+static const struct acpi_device_id i2c_hid_acpi_match[] = {
+	{"ACPI0C50", 0 },
+	{"PNP0C50", 0 },
+	{ },
+};
+MODULE_DEVICE_TABLE(acpi, i2c_hid_acpi_match);
+
+static struct i2c_driver i2c_hid_acpi_driver = {
+	.driver = {
+		.name	= "i2c_hid_acpi",
+		.pm	= &i2c_hid_core_pm,
+		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
+		.acpi_match_table = ACPI_PTR(i2c_hid_acpi_match),
+	},
+
+	.probe		= i2c_hid_acpi_probe,
+	.remove		= i2c_hid_core_remove,
+	.shutdown	= i2c_hid_core_shutdown,
+};
+
+module_i2c_driver(i2c_hid_acpi_driver);
+
+MODULE_DESCRIPTION("HID over I2C ACPI driver");
+MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
+MODULE_LICENSE("GPL");