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Linux 4.1.16
[linux/fpc-iii.git] / drivers / input / touchscreen / ti_am335x_tsc.c
blob191a1b87895f69eec25f67369fb110a0cb5b295e
1 /*
2 * TI Touch Screen driver
3 *
4 * Copyright (C) 2011 Texas Instruments Incorporated - http://www.ti.com/
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License as
8 * published by the Free Software Foundation version 2.
9 *
10 * This program is distributed "as is" WITHOUT ANY WARRANTY of any
11 * kind, whether express or implied; without even the implied warranty
12 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 */
15
16
17 #include <linux/kernel.h>
18 #include <linux/err.h>
19 #include <linux/module.h>
20 #include <linux/input.h>
21 #include <linux/slab.h>
22 #include <linux/interrupt.h>
23 #include <linux/clk.h>
24 #include <linux/platform_device.h>
25 #include <linux/io.h>
26 #include <linux/delay.h>
27 #include <linux/of.h>
28 #include <linux/of_device.h>
29 #include <linux/sort.h>
30
31 #include <linux/mfd/ti_am335x_tscadc.h>
32
33 #define ADCFSM_STEPID 0x10
34 #define SEQ_SETTLE 275
35 #define MAX_12BIT ((1 << 12) - 1)
36
37 static const int config_pins[] = {
38 STEPCONFIG_XPP,
39 STEPCONFIG_XNN,
40 STEPCONFIG_YPP,
41 STEPCONFIG_YNN,
42 };
43
44 struct titsc {
45 struct input_dev *input;
46 struct ti_tscadc_dev *mfd_tscadc;
47 unsigned int irq;
48 unsigned int wires;
49 unsigned int x_plate_resistance;
50 bool pen_down;
51 int coordinate_readouts;
52 u32 config_inp[4];
53 u32 bit_xp, bit_xn, bit_yp, bit_yn;
54 u32 inp_xp, inp_xn, inp_yp, inp_yn;
55 u32 step_mask;
56 u32 charge_delay;
57 };
58
59 static unsigned int titsc_readl(struct titsc *ts, unsigned int reg)
60 {
61 return readl(ts->mfd_tscadc->tscadc_base + reg);
62 }
63
64 static void titsc_writel(struct titsc *tsc, unsigned int reg,
65 unsigned int val)
66 {
67 writel(val, tsc->mfd_tscadc->tscadc_base + reg);
68 }
69
70 static int titsc_config_wires(struct titsc *ts_dev)
71 {
72 u32 analog_line[4];
73 u32 wire_order[4];
74 int i, bit_cfg;
75
76 for (i = 0; i < 4; i++) {
77 /*
78 * Get the order in which TSC wires are attached
79 * w.r.t. each of the analog input lines on the EVM.
80 */
81 analog_line[i] = (ts_dev->config_inp[i] & 0xF0) >> 4;
82 wire_order[i] = ts_dev->config_inp[i] & 0x0F;
83 if (WARN_ON(analog_line[i] > 7))
84 return -EINVAL;
85 if (WARN_ON(wire_order[i] > ARRAY_SIZE(config_pins)))
86 return -EINVAL;
87 }
88
89 for (i = 0; i < 4; i++) {
90 int an_line;
91 int wi_order;
92
93 an_line = analog_line[i];
94 wi_order = wire_order[i];
95 bit_cfg = config_pins[wi_order];
96 if (bit_cfg == 0)
97 return -EINVAL;
98 switch (wi_order) {
99 case 0:
100 ts_dev->bit_xp = bit_cfg;
101 ts_dev->inp_xp = an_line;
102 break;
103
104 case 1:
105 ts_dev->bit_xn = bit_cfg;
106 ts_dev->inp_xn = an_line;
107 break;
108
109 case 2:
110 ts_dev->bit_yp = bit_cfg;
111 ts_dev->inp_yp = an_line;
112 break;
113 case 3:
114 ts_dev->bit_yn = bit_cfg;
115 ts_dev->inp_yn = an_line;
116 break;
117 }
118 }
119 return 0;
120 }
121
122 static void titsc_step_config(struct titsc *ts_dev)
123 {
124 unsigned int config;
125 int i;
126 int end_step, first_step, tsc_steps;
127 u32 stepenable;
128
129 config = STEPCONFIG_MODE_HWSYNC |
130 STEPCONFIG_AVG_16 | ts_dev->bit_xp;
131 switch (ts_dev->wires) {
132 case 4:
133 config |= STEPCONFIG_INP(ts_dev->inp_yp) | ts_dev->bit_xn;
134 break;
135 case 5:
136 config |= ts_dev->bit_yn |
137 STEPCONFIG_INP_AN4 | ts_dev->bit_xn |
138 ts_dev->bit_yp;
139 break;
140 case 8:
141 config |= STEPCONFIG_INP(ts_dev->inp_yp) | ts_dev->bit_xn;
142 break;
143 }
144
145 tsc_steps = ts_dev->coordinate_readouts * 2 + 2;
146 first_step = TOTAL_STEPS - tsc_steps;
147 /* Steps 16 to 16-coordinate_readouts is for X */
148 end_step = first_step + tsc_steps;
149 for (i = end_step - ts_dev->coordinate_readouts; i < end_step; i++) {
150 titsc_writel(ts_dev, REG_STEPCONFIG(i), config);
151 titsc_writel(ts_dev, REG_STEPDELAY(i), STEPCONFIG_OPENDLY);
152 }
153
154 config = 0;
155 config = STEPCONFIG_MODE_HWSYNC |
156 STEPCONFIG_AVG_16 | ts_dev->bit_yn |
157 STEPCONFIG_INM_ADCREFM;
158 switch (ts_dev->wires) {
159 case 4:
160 config |= ts_dev->bit_yp | STEPCONFIG_INP(ts_dev->inp_xp);
161 break;
162 case 5:
163 config |= ts_dev->bit_xp | STEPCONFIG_INP_AN4 |
164 ts_dev->bit_xn | ts_dev->bit_yp;
165 break;
166 case 8:
167 config |= ts_dev->bit_yp | STEPCONFIG_INP(ts_dev->inp_xp);
168 break;
169 }
170
171 /* 1 ... coordinate_readouts is for Y */
172 end_step = first_step + ts_dev->coordinate_readouts;
173 for (i = first_step; i < end_step; i++) {
174 titsc_writel(ts_dev, REG_STEPCONFIG(i), config);
175 titsc_writel(ts_dev, REG_STEPDELAY(i), STEPCONFIG_OPENDLY);
176 }
177
178 /* Make CHARGECONFIG same as IDLECONFIG */
179
180 config = titsc_readl(ts_dev, REG_IDLECONFIG);
181 titsc_writel(ts_dev, REG_CHARGECONFIG, config);
182 titsc_writel(ts_dev, REG_CHARGEDELAY, ts_dev->charge_delay);
183
184 /* coordinate_readouts + 1 ... coordinate_readouts + 2 is for Z */
185 config = STEPCONFIG_MODE_HWSYNC |
186 STEPCONFIG_AVG_16 | ts_dev->bit_yp |
187 ts_dev->bit_xn | STEPCONFIG_INM_ADCREFM |
188 STEPCONFIG_INP(ts_dev->inp_xp);
189 titsc_writel(ts_dev, REG_STEPCONFIG(end_step), config);
190 titsc_writel(ts_dev, REG_STEPDELAY(end_step),
191 STEPCONFIG_OPENDLY);
192
193 end_step++;
194 config |= STEPCONFIG_INP(ts_dev->inp_yn);
195 titsc_writel(ts_dev, REG_STEPCONFIG(end_step), config);
196 titsc_writel(ts_dev, REG_STEPDELAY(end_step),
197 STEPCONFIG_OPENDLY);
198
199 /* The steps end ... end - readouts * 2 + 2 and bit 0 for TS_Charge */
200 stepenable = 1;
201 for (i = 0; i < tsc_steps; i++)
202 stepenable |= 1 << (first_step + i + 1);
203
204 ts_dev->step_mask = stepenable;
205 am335x_tsc_se_set_cache(ts_dev->mfd_tscadc, ts_dev->step_mask);
206 }
207
208 static int titsc_cmp_coord(const void *a, const void *b)
209 {
210 return *(int *)a - *(int *)b;
211 }
212
213 static void titsc_read_coordinates(struct titsc *ts_dev,
214 u32 *x, u32 *y, u32 *z1, u32 *z2)
215 {
216 unsigned int yvals[7], xvals[7];
217 unsigned int i, xsum = 0, ysum = 0;
218 unsigned int creads = ts_dev->coordinate_readouts;
219
220 for (i = 0; i < creads; i++) {
221 yvals[i] = titsc_readl(ts_dev, REG_FIFO0);
222 yvals[i] &= 0xfff;
223 }
224
225 *z1 = titsc_readl(ts_dev, REG_FIFO0);
226 *z1 &= 0xfff;
227 *z2 = titsc_readl(ts_dev, REG_FIFO0);
228 *z2 &= 0xfff;
229
230 for (i = 0; i < creads; i++) {
231 xvals[i] = titsc_readl(ts_dev, REG_FIFO0);
232 xvals[i] &= 0xfff;
233 }
234
235 /*
236 * If co-ordinates readouts is less than 4 then
237 * report the average. In case of 4 or more
238 * readouts, sort the co-ordinate samples, drop
239 * min and max values and report the average of
240 * remaining values.
241 */
242 if (creads <= 3) {
243 for (i = 0; i < creads; i++) {
244 ysum += yvals[i];
245 xsum += xvals[i];
246 }
247 ysum /= creads;
248 xsum /= creads;
249 } else {
250 sort(yvals, creads, sizeof(unsigned int),
251 titsc_cmp_coord, NULL);
252 sort(xvals, creads, sizeof(unsigned int),
253 titsc_cmp_coord, NULL);
254 for (i = 1; i < creads - 1; i++) {
255 ysum += yvals[i];
256 xsum += xvals[i];
257 }
258 ysum /= creads - 2;
259 xsum /= creads - 2;
260 }
261 *y = ysum;
262 *x = xsum;
263 }
264
265 static irqreturn_t titsc_irq(int irq, void *dev)
266 {
267 struct titsc *ts_dev = dev;
268 struct input_dev *input_dev = ts_dev->input;
269 unsigned int fsm, status, irqclr = 0;
270 unsigned int x = 0, y = 0;
271 unsigned int z1, z2, z;
272
273 status = titsc_readl(ts_dev, REG_RAWIRQSTATUS);
274 if (status & IRQENB_HW_PEN) {
275 ts_dev->pen_down = true;
276 titsc_writel(ts_dev, REG_IRQWAKEUP, 0x00);
277 titsc_writel(ts_dev, REG_IRQCLR, IRQENB_HW_PEN);
278 irqclr |= IRQENB_HW_PEN;
279 }
280
281 if (status & IRQENB_PENUP) {
282 fsm = titsc_readl(ts_dev, REG_ADCFSM);
283 if (fsm == ADCFSM_STEPID) {
284 ts_dev->pen_down = false;
285 input_report_key(input_dev, BTN_TOUCH, 0);
286 input_report_abs(input_dev, ABS_PRESSURE, 0);
287 input_sync(input_dev);
288 } else {
289 ts_dev->pen_down = true;
290 }
291 irqclr |= IRQENB_PENUP;
292 }
293
294 if (status & IRQENB_EOS)
295 irqclr |= IRQENB_EOS;
296
297 /*
298 * ADC and touchscreen share the IRQ line.
299 * FIFO1 interrupts are used by ADC. Handle FIFO0 IRQs here only
300 */
301 if (status & IRQENB_FIFO0THRES) {
302
303 titsc_read_coordinates(ts_dev, &x, &y, &z1, &z2);
304
305 if (ts_dev->pen_down && z1 != 0 && z2 != 0) {
306 /*
307 * Calculate pressure using formula
308 * Resistance(touch) = x plate resistance *
309 * x postion/4096 * ((z2 / z1) - 1)
310 */
311 z = z1 - z2;
312 z *= x;
313 z *= ts_dev->x_plate_resistance;
314 z /= z2;
315 z = (z + 2047) >> 12;
316
317 if (z <= MAX_12BIT) {
318 input_report_abs(input_dev, ABS_X, x);
319 input_report_abs(input_dev, ABS_Y, y);
320 input_report_abs(input_dev, ABS_PRESSURE, z);
321 input_report_key(input_dev, BTN_TOUCH, 1);
322 input_sync(input_dev);
323 }
324 }
325 irqclr |= IRQENB_FIFO0THRES;
326 }
327 if (irqclr) {
328 titsc_writel(ts_dev, REG_IRQSTATUS, irqclr);
329 if (status & IRQENB_EOS)
330 am335x_tsc_se_set_cache(ts_dev->mfd_tscadc,
331 ts_dev->step_mask);
332 return IRQ_HANDLED;
333 }
334 return IRQ_NONE;
335 }
336
337 static int titsc_parse_dt(struct platform_device *pdev,
338 struct titsc *ts_dev)
339 {
340 struct device_node *node = pdev->dev.of_node;
341 int err;
342
343 if (!node)
344 return -EINVAL;
345
346 err = of_property_read_u32(node, "ti,wires", &ts_dev->wires);
347 if (err < 0)
348 return err;
349 switch (ts_dev->wires) {
350 case 4:
351 case 5:
352 case 8:
353 break;
354 default:
355 return -EINVAL;
356 }
357
358 err = of_property_read_u32(node, "ti,x-plate-resistance",
359 &ts_dev->x_plate_resistance);
360 if (err < 0)
361 return err;
362
363 /*
364 * Try with the new binding first. If it fails, try again with
365 * bogus, miss-spelled version.
366 */
367 err = of_property_read_u32(node, "ti,coordinate-readouts",
368 &ts_dev->coordinate_readouts);
369 if (err < 0) {
370 dev_warn(&pdev->dev, "please use 'ti,coordinate-readouts' instead\n");
371 err = of_property_read_u32(node, "ti,coordiante-readouts",
372 &ts_dev->coordinate_readouts);
373 }
374
375 if (err < 0)
376 return err;
377
378 if (ts_dev->coordinate_readouts <= 0) {
379 dev_warn(&pdev->dev,
380 "invalid co-ordinate readouts, resetting it to 5\n");
381 ts_dev->coordinate_readouts = 5;
382 }
383
384 err = of_property_read_u32(node, "ti,charge-delay",
385 &ts_dev->charge_delay);
386 /*
387 * If ti,charge-delay value is not specified, then use
388 * CHARGEDLY_OPENDLY as the default value.
389 */
390 if (err < 0) {
391 ts_dev->charge_delay = CHARGEDLY_OPENDLY;
392 dev_warn(&pdev->dev, "ti,charge-delay not specified\n");
393 }
394
395 return of_property_read_u32_array(node, "ti,wire-config",
396 ts_dev->config_inp, ARRAY_SIZE(ts_dev->config_inp));
397 }
398
399 /*
400 * The functions for inserting/removing driver as a module.
401 */
402
403 static int titsc_probe(struct platform_device *pdev)
404 {
405 struct titsc *ts_dev;
406 struct input_dev *input_dev;
407 struct ti_tscadc_dev *tscadc_dev = ti_tscadc_dev_get(pdev);
408 int err;
409
410 /* Allocate memory for device */
411 ts_dev = kzalloc(sizeof(struct titsc), GFP_KERNEL);
412 input_dev = input_allocate_device();
413 if (!ts_dev || !input_dev) {
414 dev_err(&pdev->dev, "failed to allocate memory.\n");
415 err = -ENOMEM;
416 goto err_free_mem;
417 }
418
419 tscadc_dev->tsc = ts_dev;
420 ts_dev->mfd_tscadc = tscadc_dev;
421 ts_dev->input = input_dev;
422 ts_dev->irq = tscadc_dev->irq;
423
424 err = titsc_parse_dt(pdev, ts_dev);
425 if (err) {
426 dev_err(&pdev->dev, "Could not find valid DT data.\n");
427 goto err_free_mem;
428 }
429
430 err = request_irq(ts_dev->irq, titsc_irq,
431 IRQF_SHARED, pdev->dev.driver->name, ts_dev);
432 if (err) {
433 dev_err(&pdev->dev, "failed to allocate irq.\n");
434 goto err_free_mem;
435 }
436
437 titsc_writel(ts_dev, REG_IRQENABLE, IRQENB_FIFO0THRES);
438 titsc_writel(ts_dev, REG_IRQENABLE, IRQENB_EOS);
439 err = titsc_config_wires(ts_dev);
440 if (err) {
441 dev_err(&pdev->dev, "wrong i/p wire configuration\n");
442 goto err_free_irq;
443 }
444 titsc_step_config(ts_dev);
445 titsc_writel(ts_dev, REG_FIFO0THR,
446 ts_dev->coordinate_readouts * 2 + 2 - 1);
447
448 input_dev->name = "ti-tsc";
449 input_dev->dev.parent = &pdev->dev;
450
451 input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
452 input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
453
454 input_set_abs_params(input_dev, ABS_X, 0, MAX_12BIT, 0, 0);
455 input_set_abs_params(input_dev, ABS_Y, 0, MAX_12BIT, 0, 0);
456 input_set_abs_params(input_dev, ABS_PRESSURE, 0, MAX_12BIT, 0, 0);
457
458 /* register to the input system */
459 err = input_register_device(input_dev);
460 if (err)
461 goto err_free_irq;
462
463 platform_set_drvdata(pdev, ts_dev);
464 return 0;
465
466 err_free_irq:
467 free_irq(ts_dev->irq, ts_dev);
468 err_free_mem:
469 input_free_device(input_dev);
470 kfree(ts_dev);
471 return err;
472 }
473
474 static int titsc_remove(struct platform_device *pdev)
475 {
476 struct titsc *ts_dev = platform_get_drvdata(pdev);
477 u32 steps;
478
479 free_irq(ts_dev->irq, ts_dev);
480
481 /* total steps followed by the enable mask */
482 steps = 2 * ts_dev->coordinate_readouts + 2;
483 steps = (1 << steps) - 1;
484 am335x_tsc_se_clr(ts_dev->mfd_tscadc, steps);
485
486 input_unregister_device(ts_dev->input);
487
488 kfree(ts_dev);
489 return 0;
490 }
491
492 #ifdef CONFIG_PM
493 static int titsc_suspend(struct device *dev)
494 {
495 struct titsc *ts_dev = dev_get_drvdata(dev);
496 struct ti_tscadc_dev *tscadc_dev;
497 unsigned int idle;
498
499 tscadc_dev = ti_tscadc_dev_get(to_platform_device(dev));
500 if (device_may_wakeup(tscadc_dev->dev)) {
501 idle = titsc_readl(ts_dev, REG_IRQENABLE);
502 titsc_writel(ts_dev, REG_IRQENABLE,
503 (idle | IRQENB_HW_PEN));
504 titsc_writel(ts_dev, REG_IRQWAKEUP, IRQWKUP_ENB);
505 }
506 return 0;
507 }
508
509 static int titsc_resume(struct device *dev)
510 {
511 struct titsc *ts_dev = dev_get_drvdata(dev);
512 struct ti_tscadc_dev *tscadc_dev;
513
514 tscadc_dev = ti_tscadc_dev_get(to_platform_device(dev));
515 if (device_may_wakeup(tscadc_dev->dev)) {
516 titsc_writel(ts_dev, REG_IRQWAKEUP,
517 0x00);
518 titsc_writel(ts_dev, REG_IRQCLR, IRQENB_HW_PEN);
519 }
520 titsc_step_config(ts_dev);
521 titsc_writel(ts_dev, REG_FIFO0THR,
522 ts_dev->coordinate_readouts * 2 + 2 - 1);
523 return 0;
524 }
525
526 static const struct dev_pm_ops titsc_pm_ops = {
527 .suspend = titsc_suspend,
528 .resume = titsc_resume,
529 };
530 #define TITSC_PM_OPS (&titsc_pm_ops)
531 #else
532 #define TITSC_PM_OPS NULL
533 #endif
534
535 static const struct of_device_id ti_tsc_dt_ids[] = {
536 { .compatible = "ti,am3359-tsc", },
537 { }
538 };
539 MODULE_DEVICE_TABLE(of, ti_tsc_dt_ids);
540
541 static struct platform_driver ti_tsc_driver = {
542 .probe = titsc_probe,
543 .remove = titsc_remove,
544 .driver = {
545 .name = "TI-am335x-tsc",
546 .pm = TITSC_PM_OPS,
547 .of_match_table = ti_tsc_dt_ids,
548 },
549 };
550 module_platform_driver(ti_tsc_driver);
551
552 MODULE_DESCRIPTION("TI touchscreen controller driver");
553 MODULE_AUTHOR("Rachna Patil <rachna@ti.com>");
554 MODULE_LICENSE("GPL");
Linux with added FPC-III support