diff options
author | MyungJoo Ham <myungjoo.ham@samsung.com> | 2012-04-20 01:16:22 -0400 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-04-20 12:21:11 -0400 |
commit | de55d8716ac50a356cea736c29bb7db5ac3d0190 (patch) | |
tree | d63f799c7859c97ee7089609bd183d28ca63e2bf /drivers/extcon | |
parent | 7cd9c9bb57476167e83b7780dbc06d1dd601789d (diff) |
Extcon (external connector): import Android's switch class and modify.
External connector class (extcon) is based on and an extension of
Android kernel's switch class located at linux/drivers/switch/.
This patch provides the before-extension switch class moved to the
location where the extcon will be located (linux/drivers/extcon/) and
updates to handle class properly.
The before-extension class, switch class of Android kernel, commits
imported are:
switch: switch class and GPIO drivers. (splitted)
Author: Mike Lockwood <lockwood@android.com>
switch: Use device_create instead of device_create_drvdata.
Author: Arve Hjønnevåg <arve@android.com>
In this patch, upon the commits of Android kernel, we have added:
- Relocated and renamed for extcon.
- Comments, module name, and author information are updated
- Code clean for successing patches
- Bugfix: enabling write access without write functions
- Class/device/sysfs create/remove handling
- Added comments about uevents
- Format changes for extcon_dev_register() to have a parent dev.
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
--
Changes from v7
- Compiler error fixed when it is compiled as a module.
- Removed out-of-date Kconfig entry
Changes from v6
- Updated comment/strings
- Revised "Android-compatible" mode.
* Automatically activated if CONFIG_ANDROID && !CONFIG_ANDROID_SWITCH
* Creates /sys/class/switch/*, which is a copy of /sys/class/extcon/*
Changes from v5
- Split the patch
- Style fixes
- "Android-compatible" mode is enabled by Kconfig option.
Changes from v2
- Updated name_show
- Sysfs entries are handled by class itself.
- Updated the method to add/remove devices for the class
- Comments on uevent send
- Able to become a module
- Compatible with Android platform
Changes from RFC
- Renamed to extcon (external connector) from multistate switch
- Added a seperated directory (drivers/extcon)
- Added kerneldoc comments
- Removed unused variables from extcon_gpio.c
- Added ABI Documentation.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/extcon')
-rw-r--r-- | drivers/extcon/Kconfig | 17 | ||||
-rw-r--r-- | drivers/extcon/Makefile | 5 | ||||
-rw-r--r-- | drivers/extcon/extcon_class.c | 236 |
3 files changed, 258 insertions, 0 deletions
diff --git a/drivers/extcon/Kconfig b/drivers/extcon/Kconfig new file mode 100644 index 000000000000..7932e1bd9b02 --- /dev/null +++ b/drivers/extcon/Kconfig | |||
@@ -0,0 +1,17 @@ | |||
1 | menuconfig EXTCON | ||
2 | tristate "External Connector Class (extcon) support" | ||
3 | help | ||
4 | Say Y here to enable external connector class (extcon) support. | ||
5 | This allows monitoring external connectors by userspace | ||
6 | via sysfs and uevent and supports external connectors with | ||
7 | multiple states; i.e., an extcon that may have multiple | ||
8 | cables attached. For example, an external connector of a device | ||
9 | may be used to connect an HDMI cable and a AC adaptor, and to | ||
10 | host USB ports. Many of 30-pin connectors including PDMI are | ||
11 | also good examples. | ||
12 | |||
13 | if EXTCON | ||
14 | |||
15 | comment "Extcon Device Drivers" | ||
16 | |||
17 | endif # MULTISTATE_SWITCH | ||
diff --git a/drivers/extcon/Makefile b/drivers/extcon/Makefile new file mode 100644 index 000000000000..6bc69214fcd7 --- /dev/null +++ b/drivers/extcon/Makefile | |||
@@ -0,0 +1,5 @@ | |||
1 | # | ||
2 | # Makefile for external connector class (extcon) devices | ||
3 | # | ||
4 | |||
5 | obj-$(CONFIG_EXTCON) += extcon_class.o | ||
diff --git a/drivers/extcon/extcon_class.c b/drivers/extcon/extcon_class.c new file mode 100644 index 000000000000..3c46368c279a --- /dev/null +++ b/drivers/extcon/extcon_class.c | |||
@@ -0,0 +1,236 @@ | |||
1 | /* | ||
2 | * drivers/extcon/extcon_class.c | ||
3 | * | ||
4 | * External connector (extcon) class driver | ||
5 | * | ||
6 | * Copyright (C) 2012 Samsung Electronics | ||
7 | * Author: Donggeun Kim <dg77.kim@samsung.com> | ||
8 | * Author: MyungJoo Ham <myungjoo.ham@samsung.com> | ||
9 | * | ||
10 | * based on android/drivers/switch/switch_class.c | ||
11 | * Copyright (C) 2008 Google, Inc. | ||
12 | * Author: Mike Lockwood <lockwood@android.com> | ||
13 | * | ||
14 | * This software is licensed under the terms of the GNU General Public | ||
15 | * License version 2, as published by the Free Software Foundation, and | ||
16 | * may be copied, distributed, and modified under those terms. | ||
17 | * | ||
18 | * This program is distributed in the hope that it will be useful, | ||
19 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
20 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
21 | * GNU General Public License for more details. | ||
22 | * | ||
23 | */ | ||
24 | |||
25 | #include <linux/module.h> | ||
26 | #include <linux/types.h> | ||
27 | #include <linux/init.h> | ||
28 | #include <linux/device.h> | ||
29 | #include <linux/fs.h> | ||
30 | #include <linux/err.h> | ||
31 | #include <linux/extcon.h> | ||
32 | #include <linux/slab.h> | ||
33 | |||
34 | struct class *extcon_class; | ||
35 | #if defined(CONFIG_ANDROID) && !defined(CONFIG_ANDROID_SWITCH) | ||
36 | static struct class_compat *switch_class; | ||
37 | #endif /* CONFIG_ANDROID && !defined(CONFIG_ANDROID_SWITCH) */ | ||
38 | |||
39 | static ssize_t state_show(struct device *dev, struct device_attribute *attr, | ||
40 | char *buf) | ||
41 | { | ||
42 | struct extcon_dev *edev = (struct extcon_dev *) dev_get_drvdata(dev); | ||
43 | |||
44 | if (edev->print_state) { | ||
45 | int ret = edev->print_state(edev, buf); | ||
46 | |||
47 | if (ret >= 0) | ||
48 | return ret; | ||
49 | /* Use default if failed */ | ||
50 | } | ||
51 | return sprintf(buf, "%u\n", edev->state); | ||
52 | } | ||
53 | |||
54 | static ssize_t name_show(struct device *dev, struct device_attribute *attr, | ||
55 | char *buf) | ||
56 | { | ||
57 | struct extcon_dev *edev = (struct extcon_dev *) dev_get_drvdata(dev); | ||
58 | |||
59 | /* Optional callback given by the user */ | ||
60 | if (edev->print_name) { | ||
61 | int ret = edev->print_name(edev, buf); | ||
62 | if (ret >= 0) | ||
63 | return ret; | ||
64 | } | ||
65 | |||
66 | return sprintf(buf, "%s\n", dev_name(edev->dev)); | ||
67 | } | ||
68 | |||
69 | /** | ||
70 | * extcon_set_state() - Set the cable attach states of the extcon device. | ||
71 | * @edev: the extcon device | ||
72 | * @state: new cable attach status for @edev | ||
73 | * | ||
74 | * Changing the state sends uevent with environment variable containing | ||
75 | * the name of extcon device (envp[0]) and the state output (envp[1]). | ||
76 | * Tizen uses this format for extcon device to get events from ports. | ||
77 | * Android uses this format as well. | ||
78 | */ | ||
79 | void extcon_set_state(struct extcon_dev *edev, u32 state) | ||
80 | { | ||
81 | char name_buf[120]; | ||
82 | char state_buf[120]; | ||
83 | char *prop_buf; | ||
84 | char *envp[3]; | ||
85 | int env_offset = 0; | ||
86 | int length; | ||
87 | |||
88 | if (edev->state != state) { | ||
89 | edev->state = state; | ||
90 | |||
91 | prop_buf = (char *)get_zeroed_page(GFP_KERNEL); | ||
92 | if (prop_buf) { | ||
93 | length = name_show(edev->dev, NULL, prop_buf); | ||
94 | if (length > 0) { | ||
95 | if (prop_buf[length - 1] == '\n') | ||
96 | prop_buf[length - 1] = 0; | ||
97 | snprintf(name_buf, sizeof(name_buf), | ||
98 | "NAME=%s", prop_buf); | ||
99 | envp[env_offset++] = name_buf; | ||
100 | } | ||
101 | length = state_show(edev->dev, NULL, prop_buf); | ||
102 | if (length > 0) { | ||
103 | if (prop_buf[length - 1] == '\n') | ||
104 | prop_buf[length - 1] = 0; | ||
105 | snprintf(state_buf, sizeof(state_buf), | ||
106 | "STATE=%s", prop_buf); | ||
107 | envp[env_offset++] = state_buf; | ||
108 | } | ||
109 | envp[env_offset] = NULL; | ||
110 | kobject_uevent_env(&edev->dev->kobj, KOBJ_CHANGE, envp); | ||
111 | free_page((unsigned long)prop_buf); | ||
112 | } else { | ||
113 | dev_err(edev->dev, "out of memory in extcon_set_state\n"); | ||
114 | kobject_uevent(&edev->dev->kobj, KOBJ_CHANGE); | ||
115 | } | ||
116 | } | ||
117 | } | ||
118 | EXPORT_SYMBOL_GPL(extcon_set_state); | ||
119 | |||
120 | static struct device_attribute extcon_attrs[] = { | ||
121 | __ATTR_RO(state), | ||
122 | __ATTR_RO(name), | ||
123 | }; | ||
124 | |||
125 | static int create_extcon_class(void) | ||
126 | { | ||
127 | if (!extcon_class) { | ||
128 | extcon_class = class_create(THIS_MODULE, "extcon"); | ||
129 | if (IS_ERR(extcon_class)) | ||
130 | return PTR_ERR(extcon_class); | ||
131 | extcon_class->dev_attrs = extcon_attrs; | ||
132 | |||
133 | #if defined(CONFIG_ANDROID) && !defined(CONFIG_ANDROID_SWITCH) | ||
134 | switch_class = class_compat_register("switch"); | ||
135 | if (WARN(!switch_class, "cannot allocate")) | ||
136 | return -ENOMEM; | ||
137 | #endif /* CONFIG_ANDROID && !defined(CONFIG_ANDROID_SWITCH) */ | ||
138 | } | ||
139 | |||
140 | return 0; | ||
141 | } | ||
142 | |||
143 | static void extcon_cleanup(struct extcon_dev *edev, bool skip) | ||
144 | { | ||
145 | if (!skip && get_device(edev->dev)) { | ||
146 | device_unregister(edev->dev); | ||
147 | put_device(edev->dev); | ||
148 | } | ||
149 | |||
150 | kfree(edev->dev); | ||
151 | } | ||
152 | |||
153 | static void extcon_dev_release(struct device *dev) | ||
154 | { | ||
155 | struct extcon_dev *edev = (struct extcon_dev *) dev_get_drvdata(dev); | ||
156 | |||
157 | extcon_cleanup(edev, true); | ||
158 | } | ||
159 | |||
160 | /** | ||
161 | * extcon_dev_register() - Register a new extcon device | ||
162 | * @edev : the new extcon device (should be allocated before calling) | ||
163 | * @dev : the parent device for this extcon device. | ||
164 | * | ||
165 | * Among the members of edev struct, please set the "user initializing data" | ||
166 | * in any case and set the "optional callbacks" if required. However, please | ||
167 | * do not set the values of "internal data", which are initialized by | ||
168 | * this function. | ||
169 | */ | ||
170 | int extcon_dev_register(struct extcon_dev *edev, struct device *dev) | ||
171 | { | ||
172 | int ret; | ||
173 | |||
174 | if (!extcon_class) { | ||
175 | ret = create_extcon_class(); | ||
176 | if (ret < 0) | ||
177 | return ret; | ||
178 | } | ||
179 | |||
180 | edev->dev = kzalloc(sizeof(struct device), GFP_KERNEL); | ||
181 | edev->dev->parent = dev; | ||
182 | edev->dev->class = extcon_class; | ||
183 | edev->dev->release = extcon_dev_release; | ||
184 | |||
185 | dev_set_name(edev->dev, edev->name ? edev->name : dev_name(dev)); | ||
186 | ret = device_register(edev->dev); | ||
187 | if (ret) { | ||
188 | put_device(edev->dev); | ||
189 | goto err_dev; | ||
190 | } | ||
191 | #if defined(CONFIG_ANDROID) && !defined(CONFIG_ANDROID_SWITCH) | ||
192 | if (switch_class) | ||
193 | ret = class_compat_create_link(switch_class, edev->dev, | ||
194 | dev); | ||
195 | #endif /* CONFIG_ANDROID && !defined(CONFIG_ANDROID_SWITCH) */ | ||
196 | |||
197 | dev_set_drvdata(edev->dev, edev); | ||
198 | edev->state = 0; | ||
199 | return 0; | ||
200 | |||
201 | err_dev: | ||
202 | kfree(edev->dev); | ||
203 | return ret; | ||
204 | } | ||
205 | EXPORT_SYMBOL_GPL(extcon_dev_register); | ||
206 | |||
207 | /** | ||
208 | * extcon_dev_unregister() - Unregister the extcon device. | ||
209 | * @edev: the extcon device instance to be unregitered. | ||
210 | * | ||
211 | * Note that this does not call kfree(edev) because edev was not allocated | ||
212 | * by this class. | ||
213 | */ | ||
214 | void extcon_dev_unregister(struct extcon_dev *edev) | ||
215 | { | ||
216 | extcon_cleanup(edev, false); | ||
217 | } | ||
218 | EXPORT_SYMBOL_GPL(extcon_dev_unregister); | ||
219 | |||
220 | static int __init extcon_class_init(void) | ||
221 | { | ||
222 | return create_extcon_class(); | ||
223 | } | ||
224 | module_init(extcon_class_init); | ||
225 | |||
226 | static void __exit extcon_class_exit(void) | ||
227 | { | ||
228 | class_destroy(extcon_class); | ||
229 | } | ||
230 | module_exit(extcon_class_exit); | ||
231 | |||
232 | MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>"); | ||
233 | MODULE_AUTHOR("Donggeun Kim <dg77.kim@samsung.com>"); | ||
234 | MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>"); | ||
235 | MODULE_DESCRIPTION("External connector (extcon) class driver"); | ||
236 | MODULE_LICENSE("GPL"); | ||