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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#include <linux/of_platform.h>
29#include <linux/of_gpio.h>
30
31#define DRV_NAME "gpio-keys-polled"
32
33struct gpio_keys_button_data {
34 int last_state;
35 int count;
36 int threshold;
37 int can_sleep;
38};
39
40struct gpio_keys_polled_dev {
41 struct input_polled_dev *poll_dev;
42 struct device *dev;
43 const struct gpio_keys_platform_data *pdata;
44 struct gpio_keys_button_data data[0];
45};
46
47static void gpio_keys_polled_check_state(struct input_dev *input,
48 struct gpio_keys_button *button,
49 struct gpio_keys_button_data *bdata)
50{
51 int state;
52
53 if (bdata->can_sleep)
54 state = !!gpio_get_value_cansleep(button->gpio);
55 else
56 state = !!gpio_get_value(button->gpio);
57
58 if (state != bdata->last_state) {
59 unsigned int type = button->type ?: EV_KEY;
60
61 input_event(input, type, button->code,
62 !!(state ^ button->active_low));
63 input_sync(input);
64 bdata->count = 0;
65 bdata->last_state = state;
66 }
67}
68
69static void gpio_keys_polled_poll(struct input_polled_dev *dev)
70{
71 struct gpio_keys_polled_dev *bdev = dev->private;
72 const struct gpio_keys_platform_data *pdata = bdev->pdata;
73 struct input_dev *input = dev->input;
74 int i;
75
76 for (i = 0; i < pdata->nbuttons; i++) {
77 struct gpio_keys_button_data *bdata = &bdev->data[i];
78
79 if (bdata->count < bdata->threshold)
80 bdata->count++;
81 else
82 gpio_keys_polled_check_state(input, &pdata->buttons[i],
83 bdata);
84 }
85}
86
87static void gpio_keys_polled_open(struct input_polled_dev *dev)
88{
89 struct gpio_keys_polled_dev *bdev = dev->private;
90 const struct gpio_keys_platform_data *pdata = bdev->pdata;
91
92 if (pdata->enable)
93 pdata->enable(bdev->dev);
94}
95
96static void gpio_keys_polled_close(struct input_polled_dev *dev)
97{
98 struct gpio_keys_polled_dev *bdev = dev->private;
99 const struct gpio_keys_platform_data *pdata = bdev->pdata;
100
101 if (pdata->disable)
102 pdata->disable(bdev->dev);
103}
104
105#ifdef CONFIG_OF
106static struct gpio_keys_platform_data *gpio_keys_polled_get_devtree_pdata(struct device *dev)
107{
108 struct device_node *node, *pp;
109 struct gpio_keys_platform_data *pdata;
110 struct gpio_keys_button *button;
111 int error;
112 int nbuttons;
113 int i;
114
115 node = dev->of_node;
116 if (!node)
117 return NULL;
118
119 nbuttons = of_get_child_count(node);
120 if (nbuttons == 0)
121 return NULL;
122
123 pdata = kzalloc(sizeof(*pdata) + nbuttons * (sizeof *button),
124 GFP_KERNEL);
125 if (!pdata) {
126 error = -ENOMEM;
127 goto err_out;
128 }
129
130 pdata->buttons = (struct gpio_keys_button *)(pdata + 1);
131 pdata->nbuttons = nbuttons;
132
133 pdata->rep = !!of_get_property(node, "autorepeat", NULL);
134 of_property_read_u32(node, "poll-interval", &pdata->poll_interval);
135
136 i = 0;
137 for_each_child_of_node(node, pp) {
138 int gpio;
139 enum of_gpio_flags flags;
140
141 if (!of_find_property(pp, "gpios", NULL)) {
142 pdata->nbuttons--;
143 dev_warn(dev, "Found button without gpios\n");
144 continue;
145 }
146
147 gpio = of_get_gpio_flags(pp, 0, &flags);
148 if (gpio < 0) {
149 error = gpio;
150 if (error != -EPROBE_DEFER)
151 dev_err(dev,
152 "Failed to get gpio flags, error: %d\n",
153 error);
154 goto err_free_pdata;
155 }
156
157 button = &pdata->buttons[i++];
158
159 button->gpio = gpio;
160 button->active_low = flags & OF_GPIO_ACTIVE_LOW;
161
162 if (of_property_read_u32(pp, "linux,code", &button->code)) {
163 dev_err(dev, "Button without keycode: 0x%x\n",
164 button->gpio);
165 error = -EINVAL;
166 goto err_free_pdata;
167 }
168
169 button->desc = of_get_property(pp, "label", NULL);
170
171 if (of_property_read_u32(pp, "linux,input-type", &button->type))
172 button->type = EV_KEY;
173
174 button->wakeup = !!of_get_property(pp, "gpio-key,wakeup", NULL);
175
176 if (of_property_read_u32(pp, "debounce-interval",
177 &button->debounce_interval))
178 button->debounce_interval = 5;
179 }
180
181 if (pdata->nbuttons == 0) {
182 error = -EINVAL;
183 goto err_free_pdata;
184 }
185
186 return pdata;
187
188err_free_pdata:
189 kfree(pdata);
190err_out:
191 return ERR_PTR(error);
192}
193
194static struct of_device_id gpio_keys_polled_of_match[] = {
195 { .compatible = "gpio-keys-polled", },
196 { },
197};
198MODULE_DEVICE_TABLE(of, gpio_keys_polled_of_match);
199
200#else
201
202static inline struct gpio_keys_platform_data *
203gpio_keys_polled_get_devtree_pdata(struct device *dev)
204{
205 return NULL;
206}
207#endif
208
209static int gpio_keys_polled_probe(struct platform_device *pdev)
210{
211 struct device *dev = &pdev->dev;
212 const struct gpio_keys_platform_data *pdata = dev_get_platdata(dev);
213 struct gpio_keys_polled_dev *bdev;
214 struct input_polled_dev *poll_dev;
215 struct input_dev *input;
216 int error;
217 int i;
218
219 if (!pdata) {
220 pdata = gpio_keys_polled_get_devtree_pdata(dev);
221 if (IS_ERR(pdata))
222 return PTR_ERR(pdata);
223 if (!pdata) {
224 dev_err(dev, "missing platform data\n");
225 return -EINVAL;
226 }
227 }
228
229 if (!pdata->poll_interval) {
230 dev_err(dev, "missing poll_interval value\n");
231 error = -EINVAL;
232 goto err_free_pdata;
233 }
234
235 bdev = kzalloc(sizeof(struct gpio_keys_polled_dev) +
236 pdata->nbuttons * sizeof(struct gpio_keys_button_data),
237 GFP_KERNEL);
238 if (!bdev) {
239 dev_err(dev, "no memory for private data\n");
240 error = -ENOMEM;
241 goto err_free_pdata;
242 }
243
244 poll_dev = input_allocate_polled_device();
245 if (!poll_dev) {
246 dev_err(dev, "no memory for polled device\n");
247 error = -ENOMEM;
248 goto err_free_bdev;
249 }
250
251 poll_dev->private = bdev;
252 poll_dev->poll = gpio_keys_polled_poll;
253 poll_dev->poll_interval = pdata->poll_interval;
254 poll_dev->open = gpio_keys_polled_open;
255 poll_dev->close = gpio_keys_polled_close;
256
257 input = poll_dev->input;
258
259 input->name = pdev->name;
260 input->phys = DRV_NAME"/input0";
261 input->dev.parent = &pdev->dev;
262
263 input->id.bustype = BUS_HOST;
264 input->id.vendor = 0x0001;
265 input->id.product = 0x0001;
266 input->id.version = 0x0100;
267
268 __set_bit(EV_KEY, input->evbit);
269 if (pdata->rep)
270 __set_bit(EV_REP, input->evbit);
271
272 for (i = 0; i < pdata->nbuttons; i++) {
273 struct gpio_keys_button *button = &pdata->buttons[i];
274 struct gpio_keys_button_data *bdata = &bdev->data[i];
275 unsigned int gpio = button->gpio;
276 unsigned int type = button->type ?: EV_KEY;
277
278 if (button->wakeup) {
279 dev_err(dev, DRV_NAME " does not support wakeup\n");
280 error = -EINVAL;
281 goto err_free_gpio;
282 }
283
284 error = gpio_request_one(gpio, GPIOF_IN,
285 button->desc ?: DRV_NAME);
286 if (error) {
287 dev_err(dev, "unable to claim gpio %u, err=%d\n",
288 gpio, error);
289 goto err_free_gpio;
290 }
291
292 bdata->can_sleep = gpio_cansleep(gpio);
293 bdata->last_state = -1;
294 bdata->threshold = DIV_ROUND_UP(button->debounce_interval,
295 pdata->poll_interval);
296
297 input_set_capability(input, type, button->code);
298 }
299
300 bdev->poll_dev = poll_dev;
301 bdev->dev = dev;
302 bdev->pdata = pdata;
303 platform_set_drvdata(pdev, bdev);
304
305 error = input_register_polled_device(poll_dev);
306 if (error) {
307 dev_err(dev, "unable to register polled device, err=%d\n",
308 error);
309 goto err_free_gpio;
310 }
311
312
313 for (i = 0; i < pdata->nbuttons; i++)
314 gpio_keys_polled_check_state(input, &pdata->buttons[i],
315 &bdev->data[i]);
316
317 return 0;
318
319err_free_gpio:
320 while (--i >= 0)
321 gpio_free(pdata->buttons[i].gpio);
322
323 input_free_polled_device(poll_dev);
324
325err_free_bdev:
326 kfree(bdev);
327 platform_set_drvdata(pdev, NULL);
328
329err_free_pdata:
330
331 if (!dev_get_platdata(&pdev->dev))
332 kfree(pdata);
333
334 return error;
335}
336
337static int gpio_keys_polled_remove(struct platform_device *pdev)
338{
339 struct gpio_keys_polled_dev *bdev = platform_get_drvdata(pdev);
340 const struct gpio_keys_platform_data *pdata = bdev->pdata;
341 int i;
342
343 input_unregister_polled_device(bdev->poll_dev);
344
345 for (i = 0; i < pdata->nbuttons; i++)
346 gpio_free(pdata->buttons[i].gpio);
347
348 input_free_polled_device(bdev->poll_dev);
349
350
351
352
353
354 if (!dev_get_platdata(&pdev->dev))
355 kfree(pdata);
356
357 kfree(bdev);
358 platform_set_drvdata(pdev, NULL);
359
360 return 0;
361}
362
363static struct platform_driver gpio_keys_polled_driver = {
364 .probe = gpio_keys_polled_probe,
365 .remove = gpio_keys_polled_remove,
366 .driver = {
367 .name = DRV_NAME,
368 .owner = THIS_MODULE,
369 .of_match_table = of_match_ptr(gpio_keys_polled_of_match),
370 },
371};
372module_platform_driver(gpio_keys_polled_driver);
373
374MODULE_LICENSE("GPL v2");
375MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
376MODULE_DESCRIPTION("Polled GPIO Buttons driver");
377MODULE_ALIAS("platform:" DRV_NAME);
378
