This source file includes following definitions.
- gpio_keys_button_event
- gpio_keys_polled_check_state
- gpio_keys_polled_poll
- gpio_keys_polled_open
- gpio_keys_polled_close
- gpio_keys_polled_get_devtree_pdata
- gpio_keys_polled_set_abs_params
- gpio_keys_polled_probe
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15 #include <linux/kernel.h>
16 #include <linux/module.h>
17 #include <linux/slab.h>
18 #include <linux/input.h>
19 #include <linux/input-polldev.h>
20 #include <linux/ioport.h>
21 #include <linux/platform_device.h>
22 #include <linux/gpio.h>
23 #include <linux/gpio/consumer.h>
24 #include <linux/gpio_keys.h>
25 #include <linux/property.h>
26
27 #define DRV_NAME "gpio-keys-polled"
28
29 struct gpio_keys_button_data {
30 struct gpio_desc *gpiod;
31 int last_state;
32 int count;
33 int threshold;
34 };
35
36 struct gpio_keys_polled_dev {
37 struct input_polled_dev *poll_dev;
38 struct device *dev;
39 const struct gpio_keys_platform_data *pdata;
40 unsigned long rel_axis_seen[BITS_TO_LONGS(REL_CNT)];
41 unsigned long abs_axis_seen[BITS_TO_LONGS(ABS_CNT)];
42 struct gpio_keys_button_data data[0];
43 };
44
45 static void gpio_keys_button_event(struct input_polled_dev *dev,
46 const struct gpio_keys_button *button,
47 int state)
48 {
49 struct gpio_keys_polled_dev *bdev = dev->private;
50 struct input_dev *input = dev->input;
51 unsigned int type = button->type ?: EV_KEY;
52
53 if (type == EV_REL) {
54 if (state) {
55 input_event(input, type, button->code, button->value);
56 __set_bit(button->code, bdev->rel_axis_seen);
57 }
58 } else if (type == EV_ABS) {
59 if (state) {
60 input_event(input, type, button->code, button->value);
61 __set_bit(button->code, bdev->abs_axis_seen);
62 }
63 } else {
64 input_event(input, type, button->code, state);
65 input_sync(input);
66 }
67 }
68
69 static void gpio_keys_polled_check_state(struct input_polled_dev *dev,
70 const struct gpio_keys_button *button,
71 struct gpio_keys_button_data *bdata)
72 {
73 int state;
74
75 state = gpiod_get_value_cansleep(bdata->gpiod);
76 if (state < 0) {
77 dev_err(dev->input->dev.parent,
78 "failed to get gpio state: %d\n", state);
79 } else {
80 gpio_keys_button_event(dev, button, state);
81
82 if (state != bdata->last_state) {
83 bdata->count = 0;
84 bdata->last_state = state;
85 }
86 }
87 }
88
89 static void gpio_keys_polled_poll(struct input_polled_dev *dev)
90 {
91 struct gpio_keys_polled_dev *bdev = dev->private;
92 const struct gpio_keys_platform_data *pdata = bdev->pdata;
93 struct input_dev *input = dev->input;
94 int i;
95
96 memset(bdev->rel_axis_seen, 0, sizeof(bdev->rel_axis_seen));
97 memset(bdev->abs_axis_seen, 0, sizeof(bdev->abs_axis_seen));
98
99 for (i = 0; i < pdata->nbuttons; i++) {
100 struct gpio_keys_button_data *bdata = &bdev->data[i];
101
102 if (bdata->count < bdata->threshold) {
103 bdata->count++;
104 gpio_keys_button_event(dev, &pdata->buttons[i],
105 bdata->last_state);
106 } else {
107 gpio_keys_polled_check_state(dev, &pdata->buttons[i],
108 bdata);
109 }
110 }
111
112 for_each_set_bit(i, input->relbit, REL_CNT) {
113 if (!test_bit(i, bdev->rel_axis_seen))
114 input_event(input, EV_REL, i, 0);
115 }
116
117 for_each_set_bit(i, input->absbit, ABS_CNT) {
118 if (!test_bit(i, bdev->abs_axis_seen))
119 input_event(input, EV_ABS, i, 0);
120 }
121
122 input_sync(input);
123 }
124
125 static void gpio_keys_polled_open(struct input_polled_dev *dev)
126 {
127 struct gpio_keys_polled_dev *bdev = dev->private;
128 const struct gpio_keys_platform_data *pdata = bdev->pdata;
129
130 if (pdata->enable)
131 pdata->enable(bdev->dev);
132 }
133
134 static void gpio_keys_polled_close(struct input_polled_dev *dev)
135 {
136 struct gpio_keys_polled_dev *bdev = dev->private;
137 const struct gpio_keys_platform_data *pdata = bdev->pdata;
138
139 if (pdata->disable)
140 pdata->disable(bdev->dev);
141 }
142
143 static struct gpio_keys_platform_data *
144 gpio_keys_polled_get_devtree_pdata(struct device *dev)
145 {
146 struct gpio_keys_platform_data *pdata;
147 struct gpio_keys_button *button;
148 struct fwnode_handle *child;
149 int nbuttons;
150
151 nbuttons = device_get_child_node_count(dev);
152 if (nbuttons == 0)
153 return ERR_PTR(-EINVAL);
154
155 pdata = devm_kzalloc(dev, sizeof(*pdata) + nbuttons * sizeof(*button),
156 GFP_KERNEL);
157 if (!pdata)
158 return ERR_PTR(-ENOMEM);
159
160 button = (struct gpio_keys_button *)(pdata + 1);
161
162 pdata->buttons = button;
163 pdata->nbuttons = nbuttons;
164
165 pdata->rep = device_property_present(dev, "autorepeat");
166 device_property_read_u32(dev, "poll-interval", &pdata->poll_interval);
167
168 device_property_read_string(dev, "label", &pdata->name);
169
170 device_for_each_child_node(dev, child) {
171 if (fwnode_property_read_u32(child, "linux,code",
172 &button->code)) {
173 dev_err(dev, "button without keycode\n");
174 fwnode_handle_put(child);
175 return ERR_PTR(-EINVAL);
176 }
177
178 fwnode_property_read_string(child, "label", &button->desc);
179
180 if (fwnode_property_read_u32(child, "linux,input-type",
181 &button->type))
182 button->type = EV_KEY;
183
184 if (fwnode_property_read_u32(child, "linux,input-value",
185 (u32 *)&button->value))
186 button->value = 1;
187
188 button->wakeup =
189 fwnode_property_read_bool(child, "wakeup-source") ||
190
191 fwnode_property_read_bool(child, "gpio-key,wakeup");
192
193 if (fwnode_property_read_u32(child, "debounce-interval",
194 &button->debounce_interval))
195 button->debounce_interval = 5;
196
197 button++;
198 }
199
200 return pdata;
201 }
202
203 static void gpio_keys_polled_set_abs_params(struct input_dev *input,
204 const struct gpio_keys_platform_data *pdata, unsigned int code)
205 {
206 int i, min = 0, max = 0;
207
208 for (i = 0; i < pdata->nbuttons; i++) {
209 const struct gpio_keys_button *button = &pdata->buttons[i];
210
211 if (button->type != EV_ABS || button->code != code)
212 continue;
213
214 if (button->value < min)
215 min = button->value;
216 if (button->value > max)
217 max = button->value;
218 }
219
220 input_set_abs_params(input, code, min, max, 0, 0);
221 }
222
223 static const struct of_device_id gpio_keys_polled_of_match[] = {
224 { .compatible = "gpio-keys-polled", },
225 { },
226 };
227 MODULE_DEVICE_TABLE(of, gpio_keys_polled_of_match);
228
229 static int gpio_keys_polled_probe(struct platform_device *pdev)
230 {
231 struct device *dev = &pdev->dev;
232 struct fwnode_handle *child = NULL;
233 const struct gpio_keys_platform_data *pdata = dev_get_platdata(dev);
234 struct gpio_keys_polled_dev *bdev;
235 struct input_polled_dev *poll_dev;
236 struct input_dev *input;
237 int error;
238 int i;
239
240 if (!pdata) {
241 pdata = gpio_keys_polled_get_devtree_pdata(dev);
242 if (IS_ERR(pdata))
243 return PTR_ERR(pdata);
244 }
245
246 if (!pdata->poll_interval) {
247 dev_err(dev, "missing poll_interval value\n");
248 return -EINVAL;
249 }
250
251 bdev = devm_kzalloc(dev, struct_size(bdev, data, pdata->nbuttons),
252 GFP_KERNEL);
253 if (!bdev) {
254 dev_err(dev, "no memory for private data\n");
255 return -ENOMEM;
256 }
257
258 poll_dev = devm_input_allocate_polled_device(dev);
259 if (!poll_dev) {
260 dev_err(dev, "no memory for polled device\n");
261 return -ENOMEM;
262 }
263
264 poll_dev->private = bdev;
265 poll_dev->poll = gpio_keys_polled_poll;
266 poll_dev->poll_interval = pdata->poll_interval;
267 poll_dev->open = gpio_keys_polled_open;
268 poll_dev->close = gpio_keys_polled_close;
269
270 input = poll_dev->input;
271
272 input->name = pdata->name ?: pdev->name;
273 input->phys = DRV_NAME"/input0";
274
275 input->id.bustype = BUS_HOST;
276 input->id.vendor = 0x0001;
277 input->id.product = 0x0001;
278 input->id.version = 0x0100;
279
280 __set_bit(EV_KEY, input->evbit);
281 if (pdata->rep)
282 __set_bit(EV_REP, input->evbit);
283
284 for (i = 0; i < pdata->nbuttons; i++) {
285 const struct gpio_keys_button *button = &pdata->buttons[i];
286 struct gpio_keys_button_data *bdata = &bdev->data[i];
287 unsigned int type = button->type ?: EV_KEY;
288
289 if (button->wakeup) {
290 dev_err(dev, DRV_NAME " does not support wakeup\n");
291 fwnode_handle_put(child);
292 return -EINVAL;
293 }
294
295 if (!dev_get_platdata(dev)) {
296
297 child = device_get_next_child_node(dev, child);
298 if (!child) {
299 dev_err(dev, "missing child device node\n");
300 return -EINVAL;
301 }
302
303 bdata->gpiod = devm_fwnode_get_gpiod_from_child(dev,
304 NULL, child,
305 GPIOD_IN,
306 button->desc);
307 if (IS_ERR(bdata->gpiod)) {
308 error = PTR_ERR(bdata->gpiod);
309 if (error != -EPROBE_DEFER)
310 dev_err(dev,
311 "failed to get gpio: %d\n",
312 error);
313 fwnode_handle_put(child);
314 return error;
315 }
316 } else if (gpio_is_valid(button->gpio)) {
317
318
319
320
321 unsigned flags = GPIOF_IN;
322
323 if (button->active_low)
324 flags |= GPIOF_ACTIVE_LOW;
325
326 error = devm_gpio_request_one(dev, button->gpio,
327 flags, button->desc ? : DRV_NAME);
328 if (error) {
329 dev_err(dev,
330 "unable to claim gpio %u, err=%d\n",
331 button->gpio, error);
332 return error;
333 }
334
335 bdata->gpiod = gpio_to_desc(button->gpio);
336 if (!bdata->gpiod) {
337 dev_err(dev,
338 "unable to convert gpio %u to descriptor\n",
339 button->gpio);
340 return -EINVAL;
341 }
342 }
343
344 bdata->last_state = -1;
345 bdata->threshold = DIV_ROUND_UP(button->debounce_interval,
346 pdata->poll_interval);
347
348 input_set_capability(input, type, button->code);
349 if (type == EV_ABS)
350 gpio_keys_polled_set_abs_params(input, pdata,
351 button->code);
352 }
353
354 fwnode_handle_put(child);
355
356 bdev->poll_dev = poll_dev;
357 bdev->dev = dev;
358 bdev->pdata = pdata;
359
360 error = input_register_polled_device(poll_dev);
361 if (error) {
362 dev_err(dev, "unable to register polled device, err=%d\n",
363 error);
364 return error;
365 }
366
367
368 for (i = 0; i < pdata->nbuttons; i++)
369 gpio_keys_polled_check_state(poll_dev, &pdata->buttons[i],
370 &bdev->data[i]);
371
372 input_sync(input);
373
374 return 0;
375 }
376
377 static struct platform_driver gpio_keys_polled_driver = {
378 .probe = gpio_keys_polled_probe,
379 .driver = {
380 .name = DRV_NAME,
381 .of_match_table = gpio_keys_polled_of_match,
382 },
383 };
384 module_platform_driver(gpio_keys_polled_driver);
385
386 MODULE_LICENSE("GPL v2");
387 MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
388 MODULE_DESCRIPTION("Polled GPIO Buttons driver");
389 MODULE_ALIAS("platform:" DRV_NAME);