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-of.c b/drivers/hid/i2c-hid/i2c-hid-of.c
new file mode 100644
index 000000000000..4bf7cea92637
--- /dev/null
+++ b/drivers/hid/i2c-hid/i2c-hid-of.c
@@ -0,0 +1,143 @@
+/*
+ * HID over I2C Open Firmware 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/delay.h>
+#include <linux/device.h>
+#include <linux/i2c.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/pm.h>
+#include <linux/regulator/consumer.h>
+
+#include "i2c-hid.h"
+
+struct i2c_hid_of {
+	struct i2chid_ops ops;
+
+	struct i2c_client *client;
+	struct regulator_bulk_data supplies[2];
+	int post_power_delay_ms;
+};
+
+static int i2c_hid_of_power_up(struct i2chid_ops *ops)
+{
+	struct i2c_hid_of *ihid_of = container_of(ops, struct i2c_hid_of, ops);
+	struct device *dev = &ihid_of->client->dev;
+	int ret;
+
+	ret = regulator_bulk_enable(ARRAY_SIZE(ihid_of->supplies),
+				    ihid_of->supplies);
+	if (ret) {
+		dev_warn(dev, "Failed to enable supplies: %d\n", ret);
+		return ret;
+	}
+
+	if (ihid_of->post_power_delay_ms)
+		msleep(ihid_of->post_power_delay_ms);
+
+	return 0;
+}
+
+static void i2c_hid_of_power_down(struct i2chid_ops *ops)
+{
+	struct i2c_hid_of *ihid_of = container_of(ops, struct i2c_hid_of, ops);
+
+	regulator_bulk_disable(ARRAY_SIZE(ihid_of->supplies),
+			       ihid_of->supplies);
+}
+
+static int i2c_hid_of_probe(struct i2c_client *client,
+			    const struct i2c_device_id *dev_id)
+{
+	struct device *dev = &client->dev;
+	struct i2c_hid_of *ihid_of;
+	u16 hid_descriptor_address;
+	int ret;
+	u32 val;
+
+	ihid_of = devm_kzalloc(&client->dev, sizeof(*ihid_of), GFP_KERNEL);
+	if (!ihid_of)
+		return -ENOMEM;
+
+	ihid_of->ops.power_up = i2c_hid_of_power_up;
+	ihid_of->ops.power_down = i2c_hid_of_power_down;
+
+	ret = of_property_read_u32(dev->of_node, "hid-descr-addr", &val);
+	if (ret) {
+		dev_err(&client->dev, "HID register address not provided\n");
+		return -ENODEV;
+	}
+	if (val >> 16) {
+		dev_err(&client->dev, "Bad HID register address: 0x%08x\n",
+			val);
+		return -EINVAL;
+	}
+	hid_descriptor_address = val;
+
+	if (!device_property_read_u32(&client->dev, "post-power-on-delay-ms",
+				      &val))
+		ihid_of->post_power_delay_ms = val;
+
+	ihid_of->supplies[0].supply = "vdd";
+	ihid_of->supplies[1].supply = "vddl";
+	ret = devm_regulator_bulk_get(&client->dev,
+				      ARRAY_SIZE(ihid_of->supplies),
+				      ihid_of->supplies);
+	if (ret)
+		return ret;
+
+	return i2c_hid_core_probe(client, &ihid_of->ops,
+				  hid_descriptor_address);
+}
+
+static const struct of_device_id i2c_hid_of_match[] = {
+	{ .compatible = "hid-over-i2c" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, i2c_hid_of_match);
+
+static const struct i2c_device_id i2c_hid_of_id_table[] = {
+	{ "hid", 0 },
+	{ "hid-over-i2c", 0 },
+	{ },
+};
+MODULE_DEVICE_TABLE(i2c, i2c_hid_of_id_table);
+
+static struct i2c_driver i2c_hid_of_driver = {
+	.driver = {
+		.name	= "i2c_hid_of",
+		.pm	= &i2c_hid_core_pm,
+		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
+		.of_match_table = of_match_ptr(i2c_hid_of_match),
+	},
+
+	.probe		= i2c_hid_of_probe,
+	.remove		= i2c_hid_core_remove,
+	.shutdown	= i2c_hid_core_shutdown,
+	.id_table	= i2c_hid_of_id_table,
+};
+
+module_i2c_driver(i2c_hid_of_driver);
+
+MODULE_DESCRIPTION("HID over I2C OF driver");
+MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
+MODULE_LICENSE("GPL");