diff options
author | Jonathan Herman <hermanjl@cs.unc.edu> | 2013-01-22 10:38:37 -0500 |
---|---|---|
committer | Jonathan Herman <hermanjl@cs.unc.edu> | 2013-01-22 10:38:37 -0500 |
commit | fcc9d2e5a6c89d22b8b773a64fb4ad21ac318446 (patch) | |
tree | a57612d1888735a2ec7972891b68c1ac5ec8faea /drivers/switch | |
parent | 8dea78da5cee153b8af9c07a2745f6c55057fe12 (diff) |
Diffstat (limited to 'drivers/switch')
-rw-r--r-- | drivers/switch/Kconfig | 15 | ||||
-rw-r--r-- | drivers/switch/Makefile | 4 | ||||
-rw-r--r-- | drivers/switch/switch_class.c | 175 | ||||
-rw-r--r-- | drivers/switch/switch_gpio.c | 172 |
4 files changed, 366 insertions, 0 deletions
diff --git a/drivers/switch/Kconfig b/drivers/switch/Kconfig new file mode 100644 index 00000000000..52385914b9a --- /dev/null +++ b/drivers/switch/Kconfig | |||
@@ -0,0 +1,15 @@ | |||
1 | menuconfig SWITCH | ||
2 | tristate "Switch class support" | ||
3 | help | ||
4 | Say Y here to enable switch class support. This allows | ||
5 | monitoring switches by userspace via sysfs and uevent. | ||
6 | |||
7 | if SWITCH | ||
8 | |||
9 | config SWITCH_GPIO | ||
10 | tristate "GPIO Swith support" | ||
11 | depends on GENERIC_GPIO | ||
12 | help | ||
13 | Say Y here to enable GPIO based switch support. | ||
14 | |||
15 | endif # SWITCH | ||
diff --git a/drivers/switch/Makefile b/drivers/switch/Makefile new file mode 100644 index 00000000000..f7606ed4a71 --- /dev/null +++ b/drivers/switch/Makefile | |||
@@ -0,0 +1,4 @@ | |||
1 | # Switch Class Driver | ||
2 | obj-$(CONFIG_SWITCH) += switch_class.o | ||
3 | obj-$(CONFIG_SWITCH_GPIO) += switch_gpio.o | ||
4 | |||
diff --git a/drivers/switch/switch_class.c b/drivers/switch/switch_class.c new file mode 100644 index 00000000000..2c94752f645 --- /dev/null +++ b/drivers/switch/switch_class.c | |||
@@ -0,0 +1,175 @@ | |||
1 | /* | ||
2 | * drivers/switch/switch_class.c | ||
3 | * | ||
4 | * Copyright (C) 2008 Google, Inc. | ||
5 | * Copyright (C) 2012 - NVIDIA, Inc. | ||
6 | * Author: Mike Lockwood <lockwood@android.com> | ||
7 | * | ||
8 | * This software is licensed under the terms of the GNU General Public | ||
9 | * License version 2, as published by the Free Software Foundation, and | ||
10 | * may be copied, distributed, and modified under those terms. | ||
11 | * | ||
12 | * This program is distributed in the hope that it will be useful, | ||
13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
15 | * GNU General Public License for more details. | ||
16 | * | ||
17 | */ | ||
18 | |||
19 | #include <linux/module.h> | ||
20 | #include <linux/types.h> | ||
21 | #include <linux/init.h> | ||
22 | #include <linux/device.h> | ||
23 | #include <linux/fs.h> | ||
24 | #include <linux/err.h> | ||
25 | #include <linux/switch.h> | ||
26 | |||
27 | struct class *switch_class; | ||
28 | static atomic_t device_count; | ||
29 | |||
30 | static ssize_t state_show(struct device *dev, struct device_attribute *attr, | ||
31 | char *buf) | ||
32 | { | ||
33 | struct switch_dev *sdev = (struct switch_dev *) | ||
34 | dev_get_drvdata(dev); | ||
35 | |||
36 | if (sdev->print_state) { | ||
37 | int ret = sdev->print_state(sdev, buf); | ||
38 | if (ret >= 0) | ||
39 | return ret; | ||
40 | } | ||
41 | return sprintf(buf, "%d\n", sdev->state); | ||
42 | } | ||
43 | |||
44 | static ssize_t name_show(struct device *dev, struct device_attribute *attr, | ||
45 | char *buf) | ||
46 | { | ||
47 | struct switch_dev *sdev = (struct switch_dev *) | ||
48 | dev_get_drvdata(dev); | ||
49 | |||
50 | if (sdev->print_name) { | ||
51 | int ret = sdev->print_name(sdev, buf); | ||
52 | if (ret >= 0) | ||
53 | return ret; | ||
54 | } | ||
55 | return sprintf(buf, "%s\n", sdev->name); | ||
56 | } | ||
57 | |||
58 | static DEVICE_ATTR(state, S_IRUGO | S_IWUSR, state_show, NULL); | ||
59 | static DEVICE_ATTR(name, S_IRUGO | S_IWUSR, name_show, NULL); | ||
60 | |||
61 | void switch_set_state(struct switch_dev *sdev, int state) | ||
62 | { | ||
63 | char name_buf[120]; | ||
64 | char state_buf[120]; | ||
65 | char *prop_buf; | ||
66 | char *envp[3]; | ||
67 | int env_offset = 0; | ||
68 | int length; | ||
69 | |||
70 | if (sdev->state != state) { | ||
71 | sdev->state = state; | ||
72 | |||
73 | prop_buf = (char *)get_zeroed_page(GFP_KERNEL); | ||
74 | if (prop_buf) { | ||
75 | length = name_show(sdev->dev, NULL, prop_buf); | ||
76 | if (length > 0) { | ||
77 | if (prop_buf[length - 1] == '\n') | ||
78 | prop_buf[length - 1] = 0; | ||
79 | snprintf(name_buf, sizeof(name_buf), | ||
80 | "SWITCH_NAME=%s", prop_buf); | ||
81 | envp[env_offset++] = name_buf; | ||
82 | } | ||
83 | length = state_show(sdev->dev, NULL, prop_buf); | ||
84 | if (length > 0) { | ||
85 | if (prop_buf[length - 1] == '\n') | ||
86 | prop_buf[length - 1] = 0; | ||
87 | snprintf(state_buf, sizeof(state_buf), | ||
88 | "SWITCH_STATE=%s", prop_buf); | ||
89 | envp[env_offset++] = state_buf; | ||
90 | } | ||
91 | envp[env_offset] = NULL; | ||
92 | kobject_uevent_env(&sdev->dev->kobj, KOBJ_CHANGE, envp); | ||
93 | free_page((unsigned long)prop_buf); | ||
94 | } else { | ||
95 | printk(KERN_ERR "out of memory in switch_set_state\n"); | ||
96 | kobject_uevent(&sdev->dev->kobj, KOBJ_CHANGE); | ||
97 | } | ||
98 | } | ||
99 | } | ||
100 | EXPORT_SYMBOL_GPL(switch_set_state); | ||
101 | |||
102 | static int create_switch_class(void) | ||
103 | { | ||
104 | if (!switch_class) { | ||
105 | switch_class = class_create(THIS_MODULE, "switch"); | ||
106 | if (IS_ERR(switch_class)) | ||
107 | return PTR_ERR(switch_class); | ||
108 | atomic_set(&device_count, 0); | ||
109 | } | ||
110 | |||
111 | return 0; | ||
112 | } | ||
113 | |||
114 | int switch_dev_register(struct switch_dev *sdev) | ||
115 | { | ||
116 | int ret; | ||
117 | |||
118 | if (!switch_class) { | ||
119 | ret = create_switch_class(); | ||
120 | if (ret < 0) | ||
121 | return ret; | ||
122 | } | ||
123 | |||
124 | sdev->index = atomic_inc_return(&device_count); | ||
125 | sdev->dev = device_create(switch_class, NULL, | ||
126 | MKDEV(0, sdev->index), NULL, sdev->name); | ||
127 | if (IS_ERR(sdev->dev)) | ||
128 | return PTR_ERR(sdev->dev); | ||
129 | |||
130 | ret = device_create_file(sdev->dev, &dev_attr_state); | ||
131 | if (ret < 0) | ||
132 | goto err_create_file_1; | ||
133 | ret = device_create_file(sdev->dev, &dev_attr_name); | ||
134 | if (ret < 0) | ||
135 | goto err_create_file_2; | ||
136 | |||
137 | dev_set_drvdata(sdev->dev, sdev); | ||
138 | sdev->state = 0; | ||
139 | return 0; | ||
140 | |||
141 | err_create_file_2: | ||
142 | device_remove_file(sdev->dev, &dev_attr_state); | ||
143 | err_create_file_1: | ||
144 | device_destroy(switch_class, MKDEV(0, sdev->index)); | ||
145 | printk(KERN_ERR "switch: Failed to register driver %s\n", sdev->name); | ||
146 | |||
147 | return ret; | ||
148 | } | ||
149 | EXPORT_SYMBOL_GPL(switch_dev_register); | ||
150 | |||
151 | void switch_dev_unregister(struct switch_dev *sdev) | ||
152 | { | ||
153 | device_remove_file(sdev->dev, &dev_attr_name); | ||
154 | device_remove_file(sdev->dev, &dev_attr_state); | ||
155 | dev_set_drvdata(sdev->dev, NULL); | ||
156 | device_destroy(switch_class, MKDEV(0, sdev->index)); | ||
157 | } | ||
158 | EXPORT_SYMBOL_GPL(switch_dev_unregister); | ||
159 | |||
160 | static int __init switch_class_init(void) | ||
161 | { | ||
162 | return create_switch_class(); | ||
163 | } | ||
164 | |||
165 | static void __exit switch_class_exit(void) | ||
166 | { | ||
167 | class_destroy(switch_class); | ||
168 | } | ||
169 | |||
170 | module_init(switch_class_init); | ||
171 | module_exit(switch_class_exit); | ||
172 | |||
173 | MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>"); | ||
174 | MODULE_DESCRIPTION("Switch class driver"); | ||
175 | MODULE_LICENSE("GPL"); | ||
diff --git a/drivers/switch/switch_gpio.c b/drivers/switch/switch_gpio.c new file mode 100644 index 00000000000..7e9faa211e4 --- /dev/null +++ b/drivers/switch/switch_gpio.c | |||
@@ -0,0 +1,172 @@ | |||
1 | /* | ||
2 | * drivers/switch/switch_gpio.c | ||
3 | * | ||
4 | * Copyright (C) 2008 Google, Inc. | ||
5 | * Author: Mike Lockwood <lockwood@android.com> | ||
6 | * | ||
7 | * This software is licensed under the terms of the GNU General Public | ||
8 | * License version 2, as published by the Free Software Foundation, and | ||
9 | * may be copied, distributed, and modified under those terms. | ||
10 | * | ||
11 | * This program is distributed in the hope that it will be useful, | ||
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
14 | * GNU General Public License for more details. | ||
15 | * | ||
16 | */ | ||
17 | |||
18 | #include <linux/module.h> | ||
19 | #include <linux/kernel.h> | ||
20 | #include <linux/init.h> | ||
21 | #include <linux/interrupt.h> | ||
22 | #include <linux/platform_device.h> | ||
23 | #include <linux/slab.h> | ||
24 | #include <linux/switch.h> | ||
25 | #include <linux/workqueue.h> | ||
26 | #include <linux/gpio.h> | ||
27 | |||
28 | struct gpio_switch_data { | ||
29 | struct switch_dev sdev; | ||
30 | unsigned gpio; | ||
31 | const char *name_on; | ||
32 | const char *name_off; | ||
33 | const char *state_on; | ||
34 | const char *state_off; | ||
35 | int irq; | ||
36 | struct work_struct work; | ||
37 | }; | ||
38 | |||
39 | static void gpio_switch_work(struct work_struct *work) | ||
40 | { | ||
41 | int state; | ||
42 | struct gpio_switch_data *data = | ||
43 | container_of(work, struct gpio_switch_data, work); | ||
44 | |||
45 | state = gpio_get_value(data->gpio); | ||
46 | switch_set_state(&data->sdev, state); | ||
47 | } | ||
48 | |||
49 | static irqreturn_t gpio_irq_handler(int irq, void *dev_id) | ||
50 | { | ||
51 | struct gpio_switch_data *switch_data = | ||
52 | (struct gpio_switch_data *)dev_id; | ||
53 | |||
54 | schedule_work(&switch_data->work); | ||
55 | return IRQ_HANDLED; | ||
56 | } | ||
57 | |||
58 | static ssize_t switch_gpio_print_state(struct switch_dev *sdev, char *buf) | ||
59 | { | ||
60 | struct gpio_switch_data *switch_data = | ||
61 | container_of(sdev, struct gpio_switch_data, sdev); | ||
62 | const char *state; | ||
63 | if (switch_get_state(sdev)) | ||
64 | state = switch_data->state_on; | ||
65 | else | ||
66 | state = switch_data->state_off; | ||
67 | |||
68 | if (state) | ||
69 | return sprintf(buf, "%s\n", state); | ||
70 | return -1; | ||
71 | } | ||
72 | |||
73 | static int gpio_switch_probe(struct platform_device *pdev) | ||
74 | { | ||
75 | struct gpio_switch_platform_data *pdata = pdev->dev.platform_data; | ||
76 | struct gpio_switch_data *switch_data; | ||
77 | int ret = 0; | ||
78 | |||
79 | if (!pdata) | ||
80 | return -EBUSY; | ||
81 | |||
82 | switch_data = kzalloc(sizeof(struct gpio_switch_data), GFP_KERNEL); | ||
83 | if (!switch_data) | ||
84 | return -ENOMEM; | ||
85 | |||
86 | switch_data->sdev.name = pdata->name; | ||
87 | switch_data->gpio = pdata->gpio; | ||
88 | switch_data->name_on = pdata->name_on; | ||
89 | switch_data->name_off = pdata->name_off; | ||
90 | switch_data->state_on = pdata->state_on; | ||
91 | switch_data->state_off = pdata->state_off; | ||
92 | switch_data->sdev.print_state = switch_gpio_print_state; | ||
93 | |||
94 | ret = switch_dev_register(&switch_data->sdev); | ||
95 | if (ret < 0) | ||
96 | goto err_switch_dev_register; | ||
97 | |||
98 | ret = gpio_request(switch_data->gpio, pdev->name); | ||
99 | if (ret < 0) | ||
100 | goto err_request_gpio; | ||
101 | |||
102 | ret = gpio_direction_input(switch_data->gpio); | ||
103 | if (ret < 0) | ||
104 | goto err_set_gpio_input; | ||
105 | |||
106 | INIT_WORK(&switch_data->work, gpio_switch_work); | ||
107 | |||
108 | switch_data->irq = gpio_to_irq(switch_data->gpio); | ||
109 | if (switch_data->irq < 0) { | ||
110 | ret = switch_data->irq; | ||
111 | goto err_detect_irq_num_failed; | ||
112 | } | ||
113 | |||
114 | ret = request_irq(switch_data->irq, gpio_irq_handler, | ||
115 | IRQF_TRIGGER_LOW, pdev->name, switch_data); | ||
116 | if (ret < 0) | ||
117 | goto err_request_irq; | ||
118 | |||
119 | /* Perform initial detection */ | ||
120 | gpio_switch_work(&switch_data->work); | ||
121 | |||
122 | return 0; | ||
123 | |||
124 | err_request_irq: | ||
125 | err_detect_irq_num_failed: | ||
126 | err_set_gpio_input: | ||
127 | gpio_free(switch_data->gpio); | ||
128 | err_request_gpio: | ||
129 | switch_dev_unregister(&switch_data->sdev); | ||
130 | err_switch_dev_register: | ||
131 | kfree(switch_data); | ||
132 | |||
133 | return ret; | ||
134 | } | ||
135 | |||
136 | static int __devexit gpio_switch_remove(struct platform_device *pdev) | ||
137 | { | ||
138 | struct gpio_switch_data *switch_data = platform_get_drvdata(pdev); | ||
139 | |||
140 | cancel_work_sync(&switch_data->work); | ||
141 | gpio_free(switch_data->gpio); | ||
142 | switch_dev_unregister(&switch_data->sdev); | ||
143 | kfree(switch_data); | ||
144 | |||
145 | return 0; | ||
146 | } | ||
147 | |||
148 | static struct platform_driver gpio_switch_driver = { | ||
149 | .probe = gpio_switch_probe, | ||
150 | .remove = __devexit_p(gpio_switch_remove), | ||
151 | .driver = { | ||
152 | .name = "switch-gpio", | ||
153 | .owner = THIS_MODULE, | ||
154 | }, | ||
155 | }; | ||
156 | |||
157 | static int __init gpio_switch_init(void) | ||
158 | { | ||
159 | return platform_driver_register(&gpio_switch_driver); | ||
160 | } | ||
161 | |||
162 | static void __exit gpio_switch_exit(void) | ||
163 | { | ||
164 | platform_driver_unregister(&gpio_switch_driver); | ||
165 | } | ||
166 | |||
167 | module_init(gpio_switch_init); | ||
168 | module_exit(gpio_switch_exit); | ||
169 | |||
170 | MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>"); | ||
171 | MODULE_DESCRIPTION("GPIO Switch driver"); | ||
172 | MODULE_LICENSE("GPL"); | ||