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

source code of linux/drivers/input/keyboard/iqs62x-keys.c