1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Azoteq IQS620A/621/622/624/625 Keys and Switches
4 *
5 * Copyright (C) 2019 Jeff LaBundy <jeff@labundy.com>
6 */
7
8 #include <linux/device.h>
9 #include <linux/input.h>
10 #include <linux/kernel.h>
11 #include <linux/mfd/iqs62x.h>
12 #include <linux/module.h>
13 #include <linux/notifier.h>
14 #include <linux/platform_device.h>
15 #include <linux/property.h>
16 #include <linux/regmap.h>
17 #include <linux/slab.h>
18
19 enum {
20 IQS62X_SW_HALL_N,
21 IQS62X_SW_HALL_S,
22 };
23
24 static const char * const iqs62x_switch_names[] = {
25 [IQS62X_SW_HALL_N] = "hall-switch-north",
26 [IQS62X_SW_HALL_S] = "hall-switch-south",
27 };
28
29 struct iqs62x_switch_desc {
30 enum iqs62x_event_flag flag;
31 unsigned int code;
32 bool enabled;
33 };
34
35 struct iqs62x_keys_private {
36 struct iqs62x_core *iqs62x;
37 struct input_dev *input;
38 struct notifier_block notifier;
39 struct iqs62x_switch_desc switches[ARRAY_SIZE(iqs62x_switch_names)];
40 unsigned int keycode[IQS62X_NUM_KEYS];
41 unsigned int keycodemax;
42 u8 interval;
43 };
44
iqs62x_keys_parse_prop(struct platform_device * pdev,struct iqs62x_keys_private * iqs62x_keys)45 static int iqs62x_keys_parse_prop(struct platform_device *pdev,
46 struct iqs62x_keys_private *iqs62x_keys)
47 {
48 struct fwnode_handle *child;
49 unsigned int val;
50 int ret, i;
51
52 ret = device_property_count_u32(&pdev->dev, "linux,keycodes");
53 if (ret > IQS62X_NUM_KEYS) {
54 dev_err(&pdev->dev, "Too many keycodes present\n");
55 return -EINVAL;
56 } else if (ret < 0) {
57 dev_err(&pdev->dev, "Failed to count keycodes: %d\n", ret);
58 return ret;
59 }
60 iqs62x_keys->keycodemax = ret;
61
62 ret = device_property_read_u32_array(&pdev->dev, "linux,keycodes",
63 iqs62x_keys->keycode,
64 iqs62x_keys->keycodemax);
65 if (ret) {
66 dev_err(&pdev->dev, "Failed to read keycodes: %d\n", ret);
67 return ret;
68 }
69
70 for (i = 0; i < ARRAY_SIZE(iqs62x_keys->switches); i++) {
71 child = device_get_named_child_node(&pdev->dev,
72 iqs62x_switch_names[i]);
73 if (!child)
74 continue;
75
76 ret = fwnode_property_read_u32(child, "linux,code", &val);
77 if (ret) {
78 dev_err(&pdev->dev, "Failed to read switch code: %d\n",
79 ret);
80 fwnode_handle_put(child);
81 return ret;
82 }
83 iqs62x_keys->switches[i].code = val;
84 iqs62x_keys->switches[i].enabled = true;
85
86 if (fwnode_property_present(child, "azoteq,use-prox"))
87 iqs62x_keys->switches[i].flag = (i == IQS62X_SW_HALL_N ?
88 IQS62X_EVENT_HALL_N_P :
89 IQS62X_EVENT_HALL_S_P);
90 else
91 iqs62x_keys->switches[i].flag = (i == IQS62X_SW_HALL_N ?
92 IQS62X_EVENT_HALL_N_T :
93 IQS62X_EVENT_HALL_S_T);
94
95 fwnode_handle_put(child);
96 }
97
98 return 0;
99 }
100
iqs62x_keys_init(struct iqs62x_keys_private * iqs62x_keys)101 static int iqs62x_keys_init(struct iqs62x_keys_private *iqs62x_keys)
102 {
103 struct iqs62x_core *iqs62x = iqs62x_keys->iqs62x;
104 enum iqs62x_event_flag flag;
105 unsigned int event_reg, val;
106 unsigned int event_mask = 0;
107 int ret, i;
108
109 switch (iqs62x->dev_desc->prod_num) {
110 case IQS620_PROD_NUM:
111 case IQS621_PROD_NUM:
112 case IQS622_PROD_NUM:
113 event_reg = IQS620_GLBL_EVENT_MASK;
114
115 /*
116 * Discreet button, hysteresis and SAR UI flags represent keys
117 * and are unmasked if mapped to a valid keycode.
118 */
119 for (i = 0; i < iqs62x_keys->keycodemax; i++) {
120 if (iqs62x_keys->keycode[i] == KEY_RESERVED)
121 continue;
122
123 if (iqs62x_events[i].reg == IQS62X_EVENT_PROX)
124 event_mask |= iqs62x->dev_desc->prox_mask;
125 else if (iqs62x_events[i].reg == IQS62X_EVENT_HYST)
126 event_mask |= (iqs62x->dev_desc->hyst_mask |
127 iqs62x->dev_desc->sar_mask);
128 }
129
130 ret = regmap_read(iqs62x->regmap, iqs62x->dev_desc->hall_flags,
131 &val);
132 if (ret)
133 return ret;
134
135 /*
136 * Hall UI flags represent switches and are unmasked if their
137 * corresponding child nodes are present.
138 */
139 for (i = 0; i < ARRAY_SIZE(iqs62x_keys->switches); i++) {
140 if (!(iqs62x_keys->switches[i].enabled))
141 continue;
142
143 flag = iqs62x_keys->switches[i].flag;
144
145 if (iqs62x_events[flag].reg != IQS62X_EVENT_HALL)
146 continue;
147
148 event_mask |= iqs62x->dev_desc->hall_mask;
149
150 input_report_switch(iqs62x_keys->input,
151 iqs62x_keys->switches[i].code,
152 (val & iqs62x_events[flag].mask) ==
153 iqs62x_events[flag].val);
154 }
155
156 input_sync(iqs62x_keys->input);
157 break;
158
159 case IQS624_PROD_NUM:
160 event_reg = IQS624_HALL_UI;
161
162 /*
163 * Interval change events represent keys and are unmasked if
164 * either wheel movement flag is mapped to a valid keycode.
165 */
166 if (iqs62x_keys->keycode[IQS62X_EVENT_WHEEL_UP] != KEY_RESERVED)
167 event_mask |= IQS624_HALL_UI_INT_EVENT;
168
169 if (iqs62x_keys->keycode[IQS62X_EVENT_WHEEL_DN] != KEY_RESERVED)
170 event_mask |= IQS624_HALL_UI_INT_EVENT;
171
172 ret = regmap_read(iqs62x->regmap, iqs62x->dev_desc->interval,
173 &val);
174 if (ret)
175 return ret;
176
177 iqs62x_keys->interval = val;
178 break;
179
180 default:
181 return 0;
182 }
183
184 return regmap_update_bits(iqs62x->regmap, event_reg, event_mask, 0);
185 }
186
iqs62x_keys_notifier(struct notifier_block * notifier,unsigned long event_flags,void * context)187 static int iqs62x_keys_notifier(struct notifier_block *notifier,
188 unsigned long event_flags, void *context)
189 {
190 struct iqs62x_event_data *event_data = context;
191 struct iqs62x_keys_private *iqs62x_keys;
192 int ret, i;
193
194 iqs62x_keys = container_of(notifier, struct iqs62x_keys_private,
195 notifier);
196
197 if (event_flags & BIT(IQS62X_EVENT_SYS_RESET)) {
198 ret = iqs62x_keys_init(iqs62x_keys);
199 if (ret) {
200 dev_err(iqs62x_keys->input->dev.parent,
201 "Failed to re-initialize device: %d\n", ret);
202 return NOTIFY_BAD;
203 }
204
205 return NOTIFY_OK;
206 }
207
208 for (i = 0; i < iqs62x_keys->keycodemax; i++) {
209 if (iqs62x_events[i].reg == IQS62X_EVENT_WHEEL &&
210 event_data->interval == iqs62x_keys->interval)
211 continue;
212
213 input_report_key(iqs62x_keys->input, iqs62x_keys->keycode[i],
214 event_flags & BIT(i));
215 }
216
217 for (i = 0; i < ARRAY_SIZE(iqs62x_keys->switches); i++)
218 if (iqs62x_keys->switches[i].enabled)
219 input_report_switch(iqs62x_keys->input,
220 iqs62x_keys->switches[i].code,
221 event_flags &
222 BIT(iqs62x_keys->switches[i].flag));
223
224 input_sync(iqs62x_keys->input);
225
226 if (event_data->interval == iqs62x_keys->interval)
227 return NOTIFY_OK;
228
229 /*
230 * Each frame contains at most one wheel event (up or down), in which
231 * case a complementary release cycle is emulated.
232 */
233 if (event_flags & BIT(IQS62X_EVENT_WHEEL_UP)) {
234 input_report_key(iqs62x_keys->input,
235 iqs62x_keys->keycode[IQS62X_EVENT_WHEEL_UP],
236 0);
237 input_sync(iqs62x_keys->input);
238 } else if (event_flags & BIT(IQS62X_EVENT_WHEEL_DN)) {
239 input_report_key(iqs62x_keys->input,
240 iqs62x_keys->keycode[IQS62X_EVENT_WHEEL_DN],
241 0);
242 input_sync(iqs62x_keys->input);
243 }
244
245 iqs62x_keys->interval = event_data->interval;
246
247 return NOTIFY_OK;
248 }
249
iqs62x_keys_probe(struct platform_device * pdev)250 static int iqs62x_keys_probe(struct platform_device *pdev)
251 {
252 struct iqs62x_core *iqs62x = dev_get_drvdata(pdev->dev.parent);
253 struct iqs62x_keys_private *iqs62x_keys;
254 struct input_dev *input;
255 int ret, i;
256
257 iqs62x_keys = devm_kzalloc(&pdev->dev, sizeof(*iqs62x_keys),
258 GFP_KERNEL);
259 if (!iqs62x_keys)
260 return -ENOMEM;
261
262 platform_set_drvdata(pdev, iqs62x_keys);
263
264 ret = iqs62x_keys_parse_prop(pdev, iqs62x_keys);
265 if (ret)
266 return ret;
267
268 input = devm_input_allocate_device(&pdev->dev);
269 if (!input)
270 return -ENOMEM;
271
272 input->keycodemax = iqs62x_keys->keycodemax;
273 input->keycode = iqs62x_keys->keycode;
274 input->keycodesize = sizeof(*iqs62x_keys->keycode);
275
276 input->name = iqs62x->dev_desc->dev_name;
277 input->id.bustype = BUS_I2C;
278
279 for (i = 0; i < iqs62x_keys->keycodemax; i++)
280 if (iqs62x_keys->keycode[i] != KEY_RESERVED)
281 input_set_capability(input, EV_KEY,
282 iqs62x_keys->keycode[i]);
283
284 for (i = 0; i < ARRAY_SIZE(iqs62x_keys->switches); i++)
285 if (iqs62x_keys->switches[i].enabled)
286 input_set_capability(input, EV_SW,
287 iqs62x_keys->switches[i].code);
288
289 iqs62x_keys->iqs62x = iqs62x;
290 iqs62x_keys->input = input;
291
292 ret = iqs62x_keys_init(iqs62x_keys);
293 if (ret) {
294 dev_err(&pdev->dev, "Failed to initialize device: %d\n", ret);
295 return ret;
296 }
297
298 ret = input_register_device(iqs62x_keys->input);
299 if (ret) {
300 dev_err(&pdev->dev, "Failed to register device: %d\n", ret);
301 return ret;
302 }
303
304 iqs62x_keys->notifier.notifier_call = iqs62x_keys_notifier;
305 ret = blocking_notifier_chain_register(&iqs62x_keys->iqs62x->nh,
306 &iqs62x_keys->notifier);
307 if (ret)
308 dev_err(&pdev->dev, "Failed to register notifier: %d\n", ret);
309
310 return ret;
311 }
312
iqs62x_keys_remove(struct platform_device * pdev)313 static int iqs62x_keys_remove(struct platform_device *pdev)
314 {
315 struct iqs62x_keys_private *iqs62x_keys = platform_get_drvdata(pdev);
316 int ret;
317
318 ret = blocking_notifier_chain_unregister(&iqs62x_keys->iqs62x->nh,
319 &iqs62x_keys->notifier);
320 if (ret)
321 dev_err(&pdev->dev, "Failed to unregister notifier: %d\n", ret);
322
323 return 0;
324 }
325
326 static struct platform_driver iqs62x_keys_platform_driver = {
327 .driver = {
328 .name = "iqs62x-keys",
329 },
330 .probe = iqs62x_keys_probe,
331 .remove = iqs62x_keys_remove,
332 };
333 module_platform_driver(iqs62x_keys_platform_driver);
334
335 MODULE_AUTHOR("Jeff LaBundy <jeff@labundy.com>");
336 MODULE_DESCRIPTION("Azoteq IQS620A/621/622/624/625 Keys and Switches");
337 MODULE_LICENSE("GPL");
338 MODULE_ALIAS("platform:iqs62x-keys");
339
