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18#include <linux/kernel.h>
19#include <linux/module.h>
20#include <linux/init.h>
21#include <linux/slab.h>
22#include <linux/input.h>
23#include <linux/input-polldev.h>
24#include <linux/ioport.h>
25#include <linux/platform_device.h>
26#include <linux/gpio.h>
27#include <linux/gpio_keys.h>
28
29#define DRV_NAME "gpio-keys-polled"
30
31struct gpio_keys_button_data {
32 int last_state;
33 int count;
34 int threshold;
35 int can_sleep;
36};
37
38struct gpio_keys_polled_dev {
39 struct input_polled_dev *poll_dev;
40 struct device *dev;
41 struct gpio_keys_platform_data *pdata;
42 struct gpio_keys_button_data data[0];
43};
44
45static void gpio_keys_polled_check_state(struct input_dev *input,
46 struct gpio_keys_button *button,
47 struct gpio_keys_button_data *bdata)
48{
49 int state;
50
51 if (bdata->can_sleep)
52 state = !!gpio_get_value_cansleep(button->gpio);
53 else
54 state = !!gpio_get_value(button->gpio);
55
56 if (state != bdata->last_state) {
57 unsigned int type = button->type ?: EV_KEY;
58
59 input_event(input, type, button->code,
60 !!(state ^ button->active_low));
61 input_sync(input);
62 bdata->count = 0;
63 bdata->last_state = state;
64 }
65}
66
67static void gpio_keys_polled_poll(struct input_polled_dev *dev)
68{
69 struct gpio_keys_polled_dev *bdev = dev->private;
70 struct gpio_keys_platform_data *pdata = bdev->pdata;
71 struct input_dev *input = dev->input;
72 int i;
73
74 for (i = 0; i < bdev->pdata->nbuttons; i++) {
75 struct gpio_keys_button_data *bdata = &bdev->data[i];
76
77 if (bdata->count < bdata->threshold)
78 bdata->count++;
79 else
80 gpio_keys_polled_check_state(input, &pdata->buttons[i],
81 bdata);
82 }
83}
84
85static void gpio_keys_polled_open(struct input_polled_dev *dev)
86{
87 struct gpio_keys_polled_dev *bdev = dev->private;
88 struct gpio_keys_platform_data *pdata = bdev->pdata;
89
90 if (pdata->enable)
91 pdata->enable(bdev->dev);
92}
93
94static void gpio_keys_polled_close(struct input_polled_dev *dev)
95{
96 struct gpio_keys_polled_dev *bdev = dev->private;
97 struct gpio_keys_platform_data *pdata = bdev->pdata;
98
99 if (pdata->disable)
100 pdata->disable(bdev->dev);
101}
102
103static int __devinit gpio_keys_polled_probe(struct platform_device *pdev)
104{
105 struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
106 struct device *dev = &pdev->dev;
107 struct gpio_keys_polled_dev *bdev;
108 struct input_polled_dev *poll_dev;
109 struct input_dev *input;
110 int error;
111 int i;
112
113 if (!pdata || !pdata->poll_interval)
114 return -EINVAL;
115
116 bdev = kzalloc(sizeof(struct gpio_keys_polled_dev) +
117 pdata->nbuttons * sizeof(struct gpio_keys_button_data),
118 GFP_KERNEL);
119 if (!bdev) {
120 dev_err(dev, "no memory for private data\n");
121 return -ENOMEM;
122 }
123
124 poll_dev = input_allocate_polled_device();
125 if (!poll_dev) {
126 dev_err(dev, "no memory for polled device\n");
127 error = -ENOMEM;
128 goto err_free_bdev;
129 }
130
131 poll_dev->private = bdev;
132 poll_dev->poll = gpio_keys_polled_poll;
133 poll_dev->poll_interval = pdata->poll_interval;
134 poll_dev->open = gpio_keys_polled_open;
135 poll_dev->close = gpio_keys_polled_close;
136
137 input = poll_dev->input;
138
139 input->evbit[0] = BIT(EV_KEY);
140 input->name = pdev->name;
141 input->phys = DRV_NAME"/input0";
142 input->dev.parent = &pdev->dev;
143
144 input->id.bustype = BUS_HOST;
145 input->id.vendor = 0x0001;
146 input->id.product = 0x0001;
147 input->id.version = 0x0100;
148
149 for (i = 0; i < pdata->nbuttons; i++) {
150 struct gpio_keys_button *button = &pdata->buttons[i];
151 struct gpio_keys_button_data *bdata = &bdev->data[i];
152 unsigned int gpio = button->gpio;
153 unsigned int type = button->type ?: EV_KEY;
154
155 if (button->wakeup) {
156 dev_err(dev, DRV_NAME " does not support wakeup\n");
157 error = -EINVAL;
158 goto err_free_gpio;
159 }
160
161 error = gpio_request(gpio,
162 button->desc ? button->desc : DRV_NAME);
163 if (error) {
164 dev_err(dev, "unable to claim gpio %u, err=%d\n",
165 gpio, error);
166 goto err_free_gpio;
167 }
168
169 error = gpio_direction_input(gpio);
170 if (error) {
171 dev_err(dev,
172 "unable to set direction on gpio %u, err=%d\n",
173 gpio, error);
174 goto err_free_gpio;
175 }
176
177 bdata->can_sleep = gpio_cansleep(gpio);
178 bdata->last_state = -1;
179 bdata->threshold = DIV_ROUND_UP(button->debounce_interval,
180 pdata->poll_interval);
181
182 input_set_capability(input, type, button->code);
183 }
184
185 bdev->poll_dev = poll_dev;
186 bdev->dev = dev;
187 bdev->pdata = pdata;
188 platform_set_drvdata(pdev, bdev);
189
190 error = input_register_polled_device(poll_dev);
191 if (error) {
192 dev_err(dev, "unable to register polled device, err=%d\n",
193 error);
194 goto err_free_gpio;
195 }
196
197
198 for (i = 0; i < pdata->nbuttons; i++)
199 gpio_keys_polled_check_state(input, &pdata->buttons[i],
200 &bdev->data[i]);
201
202 return 0;
203
204err_free_gpio:
205 while (--i >= 0)
206 gpio_free(pdata->buttons[i].gpio);
207
208 input_free_polled_device(poll_dev);
209
210err_free_bdev:
211 kfree(bdev);
212
213 platform_set_drvdata(pdev, NULL);
214 return error;
215}
216
217static int __devexit gpio_keys_polled_remove(struct platform_device *pdev)
218{
219 struct gpio_keys_polled_dev *bdev = platform_get_drvdata(pdev);
220 struct gpio_keys_platform_data *pdata = bdev->pdata;
221 int i;
222
223 input_unregister_polled_device(bdev->poll_dev);
224
225 for (i = 0; i < pdata->nbuttons; i++)
226 gpio_free(pdata->buttons[i].gpio);
227
228 input_free_polled_device(bdev->poll_dev);
229
230 kfree(bdev);
231 platform_set_drvdata(pdev, NULL);
232
233 return 0;
234}
235
236static struct platform_driver gpio_keys_polled_driver = {
237 .probe = gpio_keys_polled_probe,
238 .remove = __devexit_p(gpio_keys_polled_remove),
239 .driver = {
240 .name = DRV_NAME,
241 .owner = THIS_MODULE,
242 },
243};
244
245static int __init gpio_keys_polled_init(void)
246{
247 return platform_driver_register(&gpio_keys_polled_driver);
248}
249
250static void __exit gpio_keys_polled_exit(void)
251{
252 platform_driver_unregister(&gpio_keys_polled_driver);
253}
254
255module_init(gpio_keys_polled_init);
256module_exit(gpio_keys_polled_exit);
257
258MODULE_LICENSE("GPL v2");
259MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
260MODULE_DESCRIPTION("Polled GPIO Buttons driver");
261MODULE_ALIAS("platform:" DRV_NAME);
262
