1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * Touchscreen driver for Dialog Semiconductor DA9034 |
4 | * |
5 | * Copyright (C) 2006-2008 Marvell International Ltd. |
6 | * Fengwei Yin <fengwei.yin@marvell.com> |
7 | * Bin Yang <bin.yang@marvell.com> |
8 | * Eric Miao <eric.miao@marvell.com> |
9 | */ |
10 | |
11 | #include <linux/module.h> |
12 | #include <linux/kernel.h> |
13 | #include <linux/delay.h> |
14 | #include <linux/platform_device.h> |
15 | #include <linux/input.h> |
16 | #include <linux/workqueue.h> |
17 | #include <linux/mfd/da903x.h> |
18 | #include <linux/slab.h> |
19 | |
20 | #define DA9034_MANUAL_CTRL 0x50 |
21 | #define DA9034_LDO_ADC_EN (1 << 4) |
22 | |
23 | #define DA9034_AUTO_CTRL1 0x51 |
24 | |
25 | #define DA9034_AUTO_CTRL2 0x52 |
26 | #define DA9034_AUTO_TSI_EN (1 << 3) |
27 | #define DA9034_PEN_DETECT (1 << 4) |
28 | |
29 | #define DA9034_TSI_CTRL1 0x53 |
30 | #define DA9034_TSI_CTRL2 0x54 |
31 | #define DA9034_TSI_X_MSB 0x6c |
32 | #define DA9034_TSI_Y_MSB 0x6d |
33 | #define DA9034_TSI_XY_LSB 0x6e |
34 | |
35 | enum { |
36 | STATE_IDLE, /* wait for pendown */ |
37 | STATE_BUSY, /* TSI busy sampling */ |
38 | STATE_STOP, /* sample available */ |
39 | STATE_WAIT, /* Wait to start next sample */ |
40 | }; |
41 | |
42 | enum { |
43 | EVENT_PEN_DOWN, |
44 | EVENT_PEN_UP, |
45 | EVENT_TSI_READY, |
46 | EVENT_TIMEDOUT, |
47 | }; |
48 | |
49 | struct da9034_touch { |
50 | struct device *da9034_dev; |
51 | struct input_dev *input_dev; |
52 | |
53 | struct delayed_work tsi_work; |
54 | struct notifier_block notifier; |
55 | |
56 | int state; |
57 | |
58 | int interval_ms; |
59 | int x_inverted; |
60 | int y_inverted; |
61 | |
62 | int last_x; |
63 | int last_y; |
64 | }; |
65 | |
66 | static inline int is_pen_down(struct da9034_touch *touch) |
67 | { |
68 | return da903x_query_status(dev: touch->da9034_dev, DA9034_STATUS_PEN_DOWN); |
69 | } |
70 | |
71 | static inline int detect_pen_down(struct da9034_touch *touch, int on) |
72 | { |
73 | if (on) |
74 | return da903x_set_bits(dev: touch->da9034_dev, |
75 | DA9034_AUTO_CTRL2, DA9034_PEN_DETECT); |
76 | else |
77 | return da903x_clr_bits(dev: touch->da9034_dev, |
78 | DA9034_AUTO_CTRL2, DA9034_PEN_DETECT); |
79 | } |
80 | |
81 | static int read_tsi(struct da9034_touch *touch) |
82 | { |
83 | uint8_t _x, _y, _v; |
84 | int ret; |
85 | |
86 | ret = da903x_read(dev: touch->da9034_dev, DA9034_TSI_X_MSB, val: &_x); |
87 | if (ret) |
88 | return ret; |
89 | |
90 | ret = da903x_read(dev: touch->da9034_dev, DA9034_TSI_Y_MSB, val: &_y); |
91 | if (ret) |
92 | return ret; |
93 | |
94 | ret = da903x_read(dev: touch->da9034_dev, DA9034_TSI_XY_LSB, val: &_v); |
95 | if (ret) |
96 | return ret; |
97 | |
98 | touch->last_x = ((_x << 2) & 0x3fc) | (_v & 0x3); |
99 | touch->last_y = ((_y << 2) & 0x3fc) | ((_v & 0xc) >> 2); |
100 | |
101 | return 0; |
102 | } |
103 | |
104 | static inline int start_tsi(struct da9034_touch *touch) |
105 | { |
106 | return da903x_set_bits(dev: touch->da9034_dev, |
107 | DA9034_AUTO_CTRL2, DA9034_AUTO_TSI_EN); |
108 | } |
109 | |
110 | static inline int stop_tsi(struct da9034_touch *touch) |
111 | { |
112 | return da903x_clr_bits(dev: touch->da9034_dev, |
113 | DA9034_AUTO_CTRL2, DA9034_AUTO_TSI_EN); |
114 | } |
115 | |
116 | static inline void report_pen_down(struct da9034_touch *touch) |
117 | { |
118 | int x = touch->last_x; |
119 | int y = touch->last_y; |
120 | |
121 | x &= 0xfff; |
122 | if (touch->x_inverted) |
123 | x = 1024 - x; |
124 | y &= 0xfff; |
125 | if (touch->y_inverted) |
126 | y = 1024 - y; |
127 | |
128 | input_report_abs(dev: touch->input_dev, ABS_X, value: x); |
129 | input_report_abs(dev: touch->input_dev, ABS_Y, value: y); |
130 | input_report_key(dev: touch->input_dev, BTN_TOUCH, value: 1); |
131 | |
132 | input_sync(dev: touch->input_dev); |
133 | } |
134 | |
135 | static inline void report_pen_up(struct da9034_touch *touch) |
136 | { |
137 | input_report_key(dev: touch->input_dev, BTN_TOUCH, value: 0); |
138 | input_sync(dev: touch->input_dev); |
139 | } |
140 | |
141 | static void da9034_event_handler(struct da9034_touch *touch, int event) |
142 | { |
143 | int err; |
144 | |
145 | switch (touch->state) { |
146 | case STATE_IDLE: |
147 | if (event != EVENT_PEN_DOWN) |
148 | break; |
149 | |
150 | /* Enable auto measurement of the TSI, this will |
151 | * automatically disable pen down detection |
152 | */ |
153 | err = start_tsi(touch); |
154 | if (err) |
155 | goto err_reset; |
156 | |
157 | touch->state = STATE_BUSY; |
158 | break; |
159 | |
160 | case STATE_BUSY: |
161 | if (event != EVENT_TSI_READY) |
162 | break; |
163 | |
164 | err = read_tsi(touch); |
165 | if (err) |
166 | goto err_reset; |
167 | |
168 | /* Disable auto measurement of the TSI, so that |
169 | * pen down status will be available |
170 | */ |
171 | err = stop_tsi(touch); |
172 | if (err) |
173 | goto err_reset; |
174 | |
175 | touch->state = STATE_STOP; |
176 | |
177 | /* FIXME: PEN_{UP/DOWN} events are expected to be |
178 | * available by stopping TSI, but this is found not |
179 | * always true, delay and simulate such an event |
180 | * here is more reliable |
181 | */ |
182 | mdelay(1); |
183 | da9034_event_handler(touch, |
184 | event: is_pen_down(touch) ? EVENT_PEN_DOWN : |
185 | EVENT_PEN_UP); |
186 | break; |
187 | |
188 | case STATE_STOP: |
189 | if (event == EVENT_PEN_DOWN) { |
190 | report_pen_down(touch); |
191 | schedule_delayed_work(dwork: &touch->tsi_work, |
192 | delay: msecs_to_jiffies(m: touch->interval_ms)); |
193 | touch->state = STATE_WAIT; |
194 | } |
195 | |
196 | if (event == EVENT_PEN_UP) { |
197 | report_pen_up(touch); |
198 | touch->state = STATE_IDLE; |
199 | } |
200 | break; |
201 | |
202 | case STATE_WAIT: |
203 | if (event != EVENT_TIMEDOUT) |
204 | break; |
205 | |
206 | if (is_pen_down(touch)) { |
207 | start_tsi(touch); |
208 | touch->state = STATE_BUSY; |
209 | } else { |
210 | report_pen_up(touch); |
211 | touch->state = STATE_IDLE; |
212 | } |
213 | break; |
214 | } |
215 | return; |
216 | |
217 | err_reset: |
218 | touch->state = STATE_IDLE; |
219 | stop_tsi(touch); |
220 | detect_pen_down(touch, on: 1); |
221 | } |
222 | |
223 | static void da9034_tsi_work(struct work_struct *work) |
224 | { |
225 | struct da9034_touch *touch = |
226 | container_of(work, struct da9034_touch, tsi_work.work); |
227 | |
228 | da9034_event_handler(touch, event: EVENT_TIMEDOUT); |
229 | } |
230 | |
231 | static int da9034_touch_notifier(struct notifier_block *nb, |
232 | unsigned long event, void *data) |
233 | { |
234 | struct da9034_touch *touch = |
235 | container_of(nb, struct da9034_touch, notifier); |
236 | |
237 | if (event & DA9034_EVENT_TSI_READY) |
238 | da9034_event_handler(touch, event: EVENT_TSI_READY); |
239 | |
240 | if ((event & DA9034_EVENT_PEN_DOWN) && touch->state == STATE_IDLE) |
241 | da9034_event_handler(touch, event: EVENT_PEN_DOWN); |
242 | |
243 | return 0; |
244 | } |
245 | |
246 | static int da9034_touch_open(struct input_dev *dev) |
247 | { |
248 | struct da9034_touch *touch = input_get_drvdata(dev); |
249 | int ret; |
250 | |
251 | ret = da903x_register_notifier(dev: touch->da9034_dev, nb: &touch->notifier, |
252 | DA9034_EVENT_PEN_DOWN | DA9034_EVENT_TSI_READY); |
253 | if (ret) |
254 | return -EBUSY; |
255 | |
256 | /* Enable ADC LDO */ |
257 | ret = da903x_set_bits(dev: touch->da9034_dev, |
258 | DA9034_MANUAL_CTRL, DA9034_LDO_ADC_EN); |
259 | if (ret) |
260 | return ret; |
261 | |
262 | /* TSI_DELAY: 3 slots, TSI_SKIP: 3 slots */ |
263 | ret = da903x_write(dev: touch->da9034_dev, DA9034_TSI_CTRL1, val: 0x1b); |
264 | if (ret) |
265 | return ret; |
266 | |
267 | ret = da903x_write(dev: touch->da9034_dev, DA9034_TSI_CTRL2, val: 0x00); |
268 | if (ret) |
269 | return ret; |
270 | |
271 | touch->state = STATE_IDLE; |
272 | detect_pen_down(touch, on: 1); |
273 | |
274 | return 0; |
275 | } |
276 | |
277 | static void da9034_touch_close(struct input_dev *dev) |
278 | { |
279 | struct da9034_touch *touch = input_get_drvdata(dev); |
280 | |
281 | da903x_unregister_notifier(dev: touch->da9034_dev, nb: &touch->notifier, |
282 | DA9034_EVENT_PEN_DOWN | DA9034_EVENT_TSI_READY); |
283 | |
284 | cancel_delayed_work_sync(dwork: &touch->tsi_work); |
285 | |
286 | touch->state = STATE_IDLE; |
287 | stop_tsi(touch); |
288 | detect_pen_down(touch, on: 0); |
289 | |
290 | /* Disable ADC LDO */ |
291 | da903x_clr_bits(dev: touch->da9034_dev, |
292 | DA9034_MANUAL_CTRL, DA9034_LDO_ADC_EN); |
293 | } |
294 | |
295 | |
296 | static int da9034_touch_probe(struct platform_device *pdev) |
297 | { |
298 | struct da9034_touch_pdata *pdata = dev_get_platdata(dev: &pdev->dev); |
299 | struct da9034_touch *touch; |
300 | struct input_dev *input_dev; |
301 | int error; |
302 | |
303 | touch = devm_kzalloc(dev: &pdev->dev, size: sizeof(struct da9034_touch), |
304 | GFP_KERNEL); |
305 | if (!touch) { |
306 | dev_err(&pdev->dev, "failed to allocate driver data\n" ); |
307 | return -ENOMEM; |
308 | } |
309 | |
310 | touch->da9034_dev = pdev->dev.parent; |
311 | |
312 | if (pdata) { |
313 | touch->interval_ms = pdata->interval_ms; |
314 | touch->x_inverted = pdata->x_inverted; |
315 | touch->y_inverted = pdata->y_inverted; |
316 | } else { |
317 | /* fallback into default */ |
318 | touch->interval_ms = 10; |
319 | } |
320 | |
321 | INIT_DELAYED_WORK(&touch->tsi_work, da9034_tsi_work); |
322 | touch->notifier.notifier_call = da9034_touch_notifier; |
323 | |
324 | input_dev = devm_input_allocate_device(&pdev->dev); |
325 | if (!input_dev) { |
326 | dev_err(&pdev->dev, "failed to allocate input device\n" ); |
327 | return -ENOMEM; |
328 | } |
329 | |
330 | input_dev->name = pdev->name; |
331 | input_dev->open = da9034_touch_open; |
332 | input_dev->close = da9034_touch_close; |
333 | input_dev->dev.parent = &pdev->dev; |
334 | |
335 | __set_bit(EV_ABS, input_dev->evbit); |
336 | __set_bit(ABS_X, input_dev->absbit); |
337 | __set_bit(ABS_Y, input_dev->absbit); |
338 | input_set_abs_params(dev: input_dev, ABS_X, min: 0, max: 1023, fuzz: 0, flat: 0); |
339 | input_set_abs_params(dev: input_dev, ABS_Y, min: 0, max: 1023, fuzz: 0, flat: 0); |
340 | |
341 | __set_bit(EV_KEY, input_dev->evbit); |
342 | __set_bit(BTN_TOUCH, input_dev->keybit); |
343 | |
344 | touch->input_dev = input_dev; |
345 | input_set_drvdata(dev: input_dev, data: touch); |
346 | |
347 | error = input_register_device(input_dev); |
348 | if (error) |
349 | return error; |
350 | |
351 | return 0; |
352 | } |
353 | |
354 | static struct platform_driver da9034_touch_driver = { |
355 | .driver = { |
356 | .name = "da9034-touch" , |
357 | }, |
358 | .probe = da9034_touch_probe, |
359 | }; |
360 | module_platform_driver(da9034_touch_driver); |
361 | |
362 | MODULE_DESCRIPTION("Touchscreen driver for Dialog Semiconductor DA9034" ); |
363 | MODULE_AUTHOR("Eric Miao <eric.miao@marvell.com>, Bin Yang <bin.yang@marvell.com>" ); |
364 | MODULE_LICENSE("GPL" ); |
365 | MODULE_ALIAS("platform:da9034-touch" ); |
366 | |