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>

drivers/hid/Makefile

@@ -138,7 +138,7 @@ obj-$(CONFIG_USB_HID)		+= usbhid/
 obj-$(CONFIG_USB_MOUSE)		+= usbhid/
 obj-$(CONFIG_USB_KBD)		+= usbhid/
 
-obj-$(CONFIG_I2C_HID)		+= i2c-hid/
+obj-$(CONFIG_I2C_HID_CORE)	+= i2c-hid/
 
 obj-$(CONFIG_INTEL_ISH_HID)	+= intel-ish-hid/
 obj-$(INTEL_ISH_FIRMWARE_DOWNLOADER)	+= intel-ish-hid/

drivers/hid/i2c-hid/Kconfig

@@ -2,18 +2,40 @@
 menu "I2C HID support"
 	depends on I2C
 
-config I2C_HID
-	tristate "HID over I2C transport layer"
+config I2C_HID_ACPI
+	tristate "HID over I2C transport layer ACPI driver"
 	default n
-	depends on I2C && INPUT
-	select HID
+	depends on I2C && INPUT && ACPI
+	help
+	  Say Y here if you use a keyboard, a touchpad, a touchscreen, or any
+	  other HID based devices which is connected to your computer via I2C.
+	  This driver supports ACPI-based systems.
+
+	  If unsure, say N.
+
+	  This support is also available as a module.  If so, the module
+	  will be called i2c-hid-acpi.  It will also build/depend on the
+	  module i2c-hid.
+
+config I2C_HID_OF
+	tristate "HID over I2C transport layer Open Firmware driver"
+	default n
+	depends on I2C && INPUT && OF
 	help
 	  Say Y here if you use a keyboard, a touchpad, a touchscreen, or any
 	  other HID based devices which is connected to your computer via I2C.
+	  This driver supports Open Firmware (Device Tree)-based systems.
 
 	  If unsure, say N.
 
 	  This support is also available as a module.  If so, the module
-	  will be called i2c-hid.
+	  will be called i2c-hid-of.  It will also build/depend on the
+	  module i2c-hid.
 
 endmenu
+
+config I2C_HID_CORE
+	tristate
+	default y if I2C_HID_ACPI=y || I2C_HID_OF=y
+	default m if I2C_HID_ACPI=m || I2C_HID_OF=m
+	select HID

drivers/hid/i2c-hid/Makefile

@@ -3,7 +3,10 @@
 # Makefile for the I2C input drivers
 #
 
-obj-$(CONFIG_I2C_HID)				+= i2c-hid.o
+obj-$(CONFIG_I2C_HID_CORE)			+= i2c-hid.o
 
 i2c-hid-objs					=  i2c-hid-core.o
 i2c-hid-$(CONFIG_DMI)				+= i2c-hid-dmi-quirks.o
+
+obj-$(CONFIG_I2C_HID_ACPI)			+= i2c-hid-acpi.o
+obj-$(CONFIG_I2C_HID_OF)			+= i2c-hid-of.o

drivers/hid/i2c-hid/i2c-hid-acpi.c

+/*
+ * 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");

drivers/hid/i2c-hid/i2c-hid-of.c

+/*
+ * 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");

drivers/hid/i2c-hid/i2c-hid.h

@@ -3,6 +3,7 @@
 #ifndef I2C_HID_H
 #define I2C_HID_H
 
+#include <linux/i2c.h>
 
 #ifdef CONFIG_DMI
 struct i2c_hid_desc *i2c_hid_get_dmi_i2c_hid_desc_override(uint8_t *i2c_name);
@@ -17,4 +18,25 @@ static inline char *i2c_hid_get_dmi_hid_report_desc_override(uint8_t *i2c_name,
 { return NULL; }
 #endif
 
+/**
+ * struct i2chid_ops - Ops provided to the core.
+ *
+ * @power_up: do sequencing to power up the device.
+ * @power_down: do sequencing to power down the device.
+ * @shutdown_tail: called at the end of shutdown.
+ */
+struct i2chid_ops {
+	int (*power_up)(struct i2chid_ops *ops);
+	void (*power_down)(struct i2chid_ops *ops);
+	void (*shutdown_tail)(struct i2chid_ops *ops);
+};
+
+int i2c_hid_core_probe(struct i2c_client *client, struct i2chid_ops *ops,
+		       u16 hid_descriptor_address);
+int i2c_hid_core_remove(struct i2c_client *client);
+
+void i2c_hid_core_shutdown(struct i2c_client *client);
+
+extern const struct dev_pm_ops i2c_hid_core_pm;
+
 #endif

include/linux/platform_data/i2c-hid.h

-/*
- * HID over I2C protocol implementation
- *
- * Copyright (c) 2012 Benjamin Tissoires <benjamin.tissoires@gmail.com>
- * Copyright (c) 2012 Ecole Nationale de l'Aviation Civile, France
- *
- * 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.
- */
-
-#ifndef __LINUX_I2C_HID_H
-#define __LINUX_I2C_HID_H
-
-#include <linux/regulator/consumer.h>
-#include <linux/types.h>
-
-/**
- * struct i2chid_platform_data - used by hid over i2c implementation.
- * @hid_descriptor_address: i2c register where the HID descriptor is stored.
- * @supplies: regulators for powering on the device.
- * @post_power_delay_ms: delay after powering on before device is usable.
- *
- * Note that it is the responsibility of the platform driver (or the acpi 5.0
- * driver, or the flattened device tree) to setup the irq related to the gpio in
- * the struct i2c_board_info.
- * The platform driver should also setup the gpio according to the device:
- *
- * A typical example is the following:
- *	irq = gpio_to_irq(intr_gpio);
- *	hkdk4412_i2c_devs5[0].irq = irq; // store the irq in i2c_board_info
- *	gpio_request(intr_gpio, "elan-irq");
- *	s3c_gpio_setpull(intr_gpio, S3C_GPIO_PULL_UP);
- */
-struct i2c_hid_platform_data {
-	u16 hid_descriptor_address;
-	struct regulator_bulk_data supplies[2];
-	int post_power_delay_ms;
-};
-
-#endif /* __LINUX_I2C_HID_H */