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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#include <linux/pm_wakeirq.h>
31
32#include <linux/mfd/ti_am335x_tscadc.h>
33
34#define ADCFSM_STEPID 0x10
35#define SEQ_SETTLE 275
36#define MAX_12BIT ((1 << 12) - 1)
37
38#define TSC_IRQENB_MASK (IRQENB_FIFO0THRES | IRQENB_EOS | IRQENB_HW_PEN)
39
40static const int config_pins[] = {
41 STEPCONFIG_XPP,
42 STEPCONFIG_XNN,
43 STEPCONFIG_YPP,
44 STEPCONFIG_YNN,
45};
46
47struct titsc {
48 struct input_dev *input;
49 struct ti_tscadc_dev *mfd_tscadc;
50 struct device *dev;
51 unsigned int irq;
52 unsigned int wires;
53 unsigned int x_plate_resistance;
54 bool pen_down;
55 int coordinate_readouts;
56 u32 config_inp[4];
57 u32 bit_xp, bit_xn, bit_yp, bit_yn;
58 u32 inp_xp, inp_xn, inp_yp, inp_yn;
59 u32 step_mask;
60 u32 charge_delay;
61};
62
63static unsigned int titsc_readl(struct titsc *ts, unsigned int reg)
64{
65 return readl(ts->mfd_tscadc->tscadc_base + reg);
66}
67
68static void titsc_writel(struct titsc *tsc, unsigned int reg,
69 unsigned int val)
70{
71 writel(val, tsc->mfd_tscadc->tscadc_base + reg);
72}
73
74static int titsc_config_wires(struct titsc *ts_dev)
75{
76 u32 analog_line[4];
77 u32 wire_order[4];
78 int i, bit_cfg;
79
80 for (i = 0; i < 4; i++) {
81 /*
82 * Get the order in which TSC wires are attached
83 * w.r.t. each of the analog input lines on the EVM.
84 */
85 analog_line[i] = (ts_dev->config_inp[i] & 0xF0) >> 4;
86 wire_order[i] = ts_dev->config_inp[i] & 0x0F;
87 if (WARN_ON(analog_line[i] > 7))
88 return -EINVAL;
89 if (WARN_ON(wire_order[i] > ARRAY_SIZE(config_pins)))
90 return -EINVAL;
91 }
92
93 for (i = 0; i < 4; i++) {
94 int an_line;
95 int wi_order;
96
97 an_line = analog_line[i];
98 wi_order = wire_order[i];
99 bit_cfg = config_pins[wi_order];
100 if (bit_cfg == 0)
101 return -EINVAL;
102 switch (wi_order) {
103 case 0:
104 ts_dev->bit_xp = bit_cfg;
105 ts_dev->inp_xp = an_line;
106 break;
107
108 case 1:
109 ts_dev->bit_xn = bit_cfg;
110 ts_dev->inp_xn = an_line;
111 break;
112
113 case 2:
114 ts_dev->bit_yp = bit_cfg;
115 ts_dev->inp_yp = an_line;
116 break;
117 case 3:
118 ts_dev->bit_yn = bit_cfg;
119 ts_dev->inp_yn = an_line;
120 break;
121 }
122 }
123 return 0;
124}
125
126static void titsc_step_config(struct titsc *ts_dev)
127{
128 unsigned int config;
129 int i, n;
130 int end_step, first_step, tsc_steps;
131 u32 stepenable;
132
133 config = STEPCONFIG_MODE_HWSYNC |
134 STEPCONFIG_AVG_16 | ts_dev->bit_xp |
135 STEPCONFIG_INM_ADCREFM;
136 switch (ts_dev->wires) {
137 case 4:
138 config |= STEPCONFIG_INP(ts_dev->inp_yp) | ts_dev->bit_xn;
139 break;
140 case 5:
141 config |= ts_dev->bit_yn |
142 STEPCONFIG_INP_AN4 | ts_dev->bit_xn |
143 ts_dev->bit_yp;
144 break;
145 case 8:
146 config |= STEPCONFIG_INP(ts_dev->inp_yp) | ts_dev->bit_xn;
147 break;
148 }
149
150 tsc_steps = ts_dev->coordinate_readouts * 2 + 2;
151 first_step = TOTAL_STEPS - tsc_steps;
152 /* Steps 16 to 16-coordinate_readouts is for X */
153 end_step = first_step + tsc_steps;
154 n = 0;
155 for (i = end_step - ts_dev->coordinate_readouts; i < end_step; i++) {
156 titsc_writel(ts_dev, REG_STEPCONFIG(i), config);
157 titsc_writel(ts_dev, REG_STEPDELAY(i),
158 n++ == 0 ? STEPCONFIG_OPENDLY : 0);
159 }
160
161 config = 0;
162 config = STEPCONFIG_MODE_HWSYNC |
163 STEPCONFIG_AVG_16 | ts_dev->bit_yn |
164 STEPCONFIG_INM_ADCREFM;
165 switch (ts_dev->wires) {
166 case 4:
167 config |= ts_dev->bit_yp | STEPCONFIG_INP(ts_dev->inp_xp);
168 break;
169 case 5:
170 config |= ts_dev->bit_xp | STEPCONFIG_INP_AN4 |
171 STEPCONFIG_XNP | STEPCONFIG_YPN;
172 break;
173 case 8:
174 config |= ts_dev->bit_yp | STEPCONFIG_INP(ts_dev->inp_xp);
175 break;
176 }
177
178 /* 1 ... coordinate_readouts is for Y */
179 end_step = first_step + ts_dev->coordinate_readouts;
180 n = 0;
181 for (i = first_step; i < end_step; i++) {
182 titsc_writel(ts_dev, REG_STEPCONFIG(i), config);
183 titsc_writel(ts_dev, REG_STEPDELAY(i),
184 n++ == 0 ? STEPCONFIG_OPENDLY : 0);
185 }
186
187 /* Make CHARGECONFIG same as IDLECONFIG */
188
189 config = titsc_readl(ts_dev, REG_IDLECONFIG);
190 titsc_writel(ts_dev, REG_CHARGECONFIG, config);
191 titsc_writel(ts_dev, REG_CHARGEDELAY, ts_dev->charge_delay);
192
193 /* coordinate_readouts + 1 ... coordinate_readouts + 2 is for Z */
194 config = STEPCONFIG_MODE_HWSYNC |
195 STEPCONFIG_AVG_16 | ts_dev->bit_yp |
196 ts_dev->bit_xn | STEPCONFIG_INM_ADCREFM |
197 STEPCONFIG_INP(ts_dev->inp_xp);
198 titsc_writel(ts_dev, REG_STEPCONFIG(end_step), config);
199 titsc_writel(ts_dev, REG_STEPDELAY(end_step),
200 STEPCONFIG_OPENDLY);
201
202 end_step++;
203 config = STEPCONFIG_MODE_HWSYNC |
204 STEPCONFIG_AVG_16 | ts_dev->bit_yp |
205 ts_dev->bit_xn | STEPCONFIG_INM_ADCREFM |
206 STEPCONFIG_INP(ts_dev->inp_yn);
207 titsc_writel(ts_dev, REG_STEPCONFIG(end_step), config);
208 titsc_writel(ts_dev, REG_STEPDELAY(end_step),
209 STEPCONFIG_OPENDLY);
210
211 /* The steps end ... end - readouts * 2 + 2 and bit 0 for TS_Charge */
212 stepenable = 1;
213 for (i = 0; i < tsc_steps; i++)
214 stepenable |= 1 << (first_step + i + 1);
215
216 ts_dev->step_mask = stepenable;
217 am335x_tsc_se_set_cache(ts_dev->mfd_tscadc, ts_dev->step_mask);
218}
219
220static int titsc_cmp_coord(const void *a, const void *b)
221{
222 return *(int *)a - *(int *)b;
223}
224
225static void titsc_read_coordinates(struct titsc *ts_dev,
226 u32 *x, u32 *y, u32 *z1, u32 *z2)
227{
228 unsigned int yvals[7], xvals[7];
229 unsigned int i, xsum = 0, ysum = 0;
230 unsigned int creads = ts_dev->coordinate_readouts;
231
232 for (i = 0; i < creads; i++) {
233 yvals[i] = titsc_readl(ts_dev, REG_FIFO0);
234 yvals[i] &= 0xfff;
235 }
236
237 *z1 = titsc_readl(ts_dev, REG_FIFO0);
238 *z1 &= 0xfff;
239 *z2 = titsc_readl(ts_dev, REG_FIFO0);
240 *z2 &= 0xfff;
241
242 for (i = 0; i < creads; i++) {
243 xvals[i] = titsc_readl(ts_dev, REG_FIFO0);
244 xvals[i] &= 0xfff;
245 }
246
247 /*
248 * If co-ordinates readouts is less than 4 then
249 * report the average. In case of 4 or more
250 * readouts, sort the co-ordinate samples, drop
251 * min and max values and report the average of
252 * remaining values.
253 */
254 if (creads <= 3) {
255 for (i = 0; i < creads; i++) {
256 ysum += yvals[i];
257 xsum += xvals[i];
258 }
259 ysum /= creads;
260 xsum /= creads;
261 } else {
262 sort(yvals, creads, sizeof(unsigned int),
263 titsc_cmp_coord, NULL);
264 sort(xvals, creads, sizeof(unsigned int),
265 titsc_cmp_coord, NULL);
266 for (i = 1; i < creads - 1; i++) {
267 ysum += yvals[i];
268 xsum += xvals[i];
269 }
270 ysum /= creads - 2;
271 xsum /= creads - 2;
272 }
273 *y = ysum;
274 *x = xsum;
275}
276
277static irqreturn_t titsc_irq(int irq, void *dev)
278{
279 struct titsc *ts_dev = dev;
280 struct input_dev *input_dev = ts_dev->input;
281 unsigned int fsm, status, irqclr = 0;
282 unsigned int x = 0, y = 0;
283 unsigned int z1, z2, z;
284
285 status = titsc_readl(ts_dev, REG_RAWIRQSTATUS);
286 if (status & IRQENB_HW_PEN) {
287 ts_dev->pen_down = true;
288 irqclr |= IRQENB_HW_PEN;
289 pm_stay_awake(ts_dev->dev);
290 }
291
292 if (status & IRQENB_PENUP) {
293 fsm = titsc_readl(ts_dev, REG_ADCFSM);
294 if (fsm == ADCFSM_STEPID) {
295 ts_dev->pen_down = false;
296 input_report_key(input_dev, BTN_TOUCH, 0);
297 input_report_abs(input_dev, ABS_PRESSURE, 0);
298 input_sync(input_dev);
299 pm_relax(ts_dev->dev);
300 } else {
301 ts_dev->pen_down = true;
302 }
303 irqclr |= IRQENB_PENUP;
304 }
305
306 if (status & IRQENB_EOS)
307 irqclr |= IRQENB_EOS;
308
309 /*
310 * ADC and touchscreen share the IRQ line.
311 * FIFO1 interrupts are used by ADC. Handle FIFO0 IRQs here only
312 */
313 if (status & IRQENB_FIFO0THRES) {
314
315 titsc_read_coordinates(ts_dev, &x, &y, &z1, &z2);
316
317 if (ts_dev->pen_down && z1 != 0 && z2 != 0) {
318 /*
319 * Calculate pressure using formula
320 * Resistance(touch) = x plate resistance *
321 * x position/4096 * ((z2 / z1) - 1)
322 */
323 z = z1 - z2;
324 z *= x;
325 z *= ts_dev->x_plate_resistance;
326 z /= z2;
327 z = (z + 2047) >> 12;
328
329 if (z <= MAX_12BIT) {
330 input_report_abs(input_dev, ABS_X, x);
331 input_report_abs(input_dev, ABS_Y, y);
332 input_report_abs(input_dev, ABS_PRESSURE, z);
333 input_report_key(input_dev, BTN_TOUCH, 1);
334 input_sync(input_dev);
335 }
336 }
337 irqclr |= IRQENB_FIFO0THRES;
338 }
339 if (irqclr) {
340 titsc_writel(ts_dev, REG_IRQSTATUS, irqclr);
341 if (status & IRQENB_EOS)
342 am335x_tsc_se_set_cache(ts_dev->mfd_tscadc,
343 ts_dev->step_mask);
344 return IRQ_HANDLED;
345 }
346 return IRQ_NONE;
347}
348
349static int titsc_parse_dt(struct platform_device *pdev,
350 struct titsc *ts_dev)
351{
352 struct device_node *node = pdev->dev.of_node;
353 int err;
354
355 if (!node)
356 return -EINVAL;
357
358 err = of_property_read_u32(node, "ti,wires", &ts_dev->wires);
359 if (err < 0)
360 return err;
361 switch (ts_dev->wires) {
362 case 4:
363 case 5:
364 case 8:
365 break;
366 default:
367 return -EINVAL;
368 }
369
370 err = of_property_read_u32(node, "ti,x-plate-resistance",
371 &ts_dev->x_plate_resistance);
372 if (err < 0)
373 return err;
374
375 /*
376 * Try with the new binding first. If it fails, try again with
377 * bogus, miss-spelled version.
378 */
379 err = of_property_read_u32(node, "ti,coordinate-readouts",
380 &ts_dev->coordinate_readouts);
381 if (err < 0) {
382 dev_warn(&pdev->dev, "please use 'ti,coordinate-readouts' instead\n");
383 err = of_property_read_u32(node, "ti,coordiante-readouts",
384 &ts_dev->coordinate_readouts);
385 }
386
387 if (err < 0)
388 return err;
389
390 if (ts_dev->coordinate_readouts <= 0) {
391 dev_warn(&pdev->dev,
392 "invalid co-ordinate readouts, resetting it to 5\n");
393 ts_dev->coordinate_readouts = 5;
394 }
395
396 err = of_property_read_u32(node, "ti,charge-delay",
397 &ts_dev->charge_delay);
398 /*
399 * If ti,charge-delay value is not specified, then use
400 * CHARGEDLY_OPENDLY as the default value.
401 */
402 if (err < 0) {
403 ts_dev->charge_delay = CHARGEDLY_OPENDLY;
404 dev_warn(&pdev->dev, "ti,charge-delay not specified\n");
405 }
406
407 return of_property_read_u32_array(node, "ti,wire-config",
408 ts_dev->config_inp, ARRAY_SIZE(ts_dev->config_inp));
409}
410
411/*
412 * The functions for inserting/removing driver as a module.
413 */
414
415static int titsc_probe(struct platform_device *pdev)
416{
417 struct titsc *ts_dev;
418 struct input_dev *input_dev;
419 struct ti_tscadc_dev *tscadc_dev = ti_tscadc_dev_get(pdev);
420 int err;
421
422 /* Allocate memory for device */
423 ts_dev = kzalloc(sizeof(*ts_dev), GFP_KERNEL);
424 input_dev = input_allocate_device();
425 if (!ts_dev || !input_dev) {
426 dev_err(&pdev->dev, "failed to allocate memory.\n");
427 err = -ENOMEM;
428 goto err_free_mem;
429 }
430
431 tscadc_dev->tsc = ts_dev;
432 ts_dev->mfd_tscadc = tscadc_dev;
433 ts_dev->input = input_dev;
434 ts_dev->irq = tscadc_dev->irq;
435 ts_dev->dev = &pdev->dev;
436
437 err = titsc_parse_dt(pdev, ts_dev);
438 if (err) {
439 dev_err(&pdev->dev, "Could not find valid DT data.\n");
440 goto err_free_mem;
441 }
442
443 err = request_irq(ts_dev->irq, titsc_irq,
444 IRQF_SHARED, pdev->dev.driver->name, ts_dev);
445 if (err) {
446 dev_err(&pdev->dev, "failed to allocate irq.\n");
447 goto err_free_mem;
448 }
449
450 device_init_wakeup(&pdev->dev, true);
451 err = dev_pm_set_wake_irq(&pdev->dev, ts_dev->irq);
452 if (err)
453 dev_err(&pdev->dev, "irq wake enable failed.\n");
454
455 titsc_writel(ts_dev, REG_IRQSTATUS, TSC_IRQENB_MASK);
456 titsc_writel(ts_dev, REG_IRQENABLE, IRQENB_FIFO0THRES);
457 titsc_writel(ts_dev, REG_IRQENABLE, IRQENB_EOS);
458 err = titsc_config_wires(ts_dev);
459 if (err) {
460 dev_err(&pdev->dev, "wrong i/p wire configuration\n");
461 goto err_free_irq;
462 }
463 titsc_step_config(ts_dev);
464 titsc_writel(ts_dev, REG_FIFO0THR,
465 ts_dev->coordinate_readouts * 2 + 2 - 1);
466
467 input_dev->name = "ti-tsc";
468 input_dev->dev.parent = &pdev->dev;
469
470 input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
471 input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
472
473 input_set_abs_params(input_dev, ABS_X, 0, MAX_12BIT, 0, 0);
474 input_set_abs_params(input_dev, ABS_Y, 0, MAX_12BIT, 0, 0);
475 input_set_abs_params(input_dev, ABS_PRESSURE, 0, MAX_12BIT, 0, 0);
476
477 /* register to the input system */
478 err = input_register_device(input_dev);
479 if (err)
480 goto err_free_irq;
481
482 platform_set_drvdata(pdev, ts_dev);
483 return 0;
484
485err_free_irq:
486 dev_pm_clear_wake_irq(&pdev->dev);
487 device_init_wakeup(&pdev->dev, false);
488 free_irq(ts_dev->irq, ts_dev);
489err_free_mem:
490 input_free_device(input_dev);
491 kfree(ts_dev);
492 return err;
493}
494
495static int titsc_remove(struct platform_device *pdev)
496{
497 struct titsc *ts_dev = platform_get_drvdata(pdev);
498 u32 steps;
499
500 dev_pm_clear_wake_irq(&pdev->dev);
501 device_init_wakeup(&pdev->dev, false);
502 free_irq(ts_dev->irq, ts_dev);
503
504 /* total steps followed by the enable mask */
505 steps = 2 * ts_dev->coordinate_readouts + 2;
506 steps = (1 << steps) - 1;
507 am335x_tsc_se_clr(ts_dev->mfd_tscadc, steps);
508
509 input_unregister_device(ts_dev->input);
510
511 kfree(ts_dev);
512 return 0;
513}
514
515static int __maybe_unused titsc_suspend(struct device *dev)
516{
517 struct titsc *ts_dev = dev_get_drvdata(dev);
518 unsigned int idle;
519
520 if (device_may_wakeup(dev)) {
521 titsc_writel(ts_dev, REG_IRQSTATUS, TSC_IRQENB_MASK);
522 idle = titsc_readl(ts_dev, REG_IRQENABLE);
523 titsc_writel(ts_dev, REG_IRQENABLE,
524 (idle | IRQENB_HW_PEN));
525 titsc_writel(ts_dev, REG_IRQWAKEUP, IRQWKUP_ENB);
526 }
527 return 0;
528}
529
530static int __maybe_unused titsc_resume(struct device *dev)
531{
532 struct titsc *ts_dev = dev_get_drvdata(dev);
533
534 if (device_may_wakeup(dev)) {
535 titsc_writel(ts_dev, REG_IRQWAKEUP,
536 0x00);
537 titsc_writel(ts_dev, REG_IRQCLR, IRQENB_HW_PEN);
538 pm_relax(dev);
539 }
540 titsc_step_config(ts_dev);
541 titsc_writel(ts_dev, REG_FIFO0THR,
542 ts_dev->coordinate_readouts * 2 + 2 - 1);
543 return 0;
544}
545
546static SIMPLE_DEV_PM_OPS(titsc_pm_ops, titsc_suspend, titsc_resume);
547
548static const struct of_device_id ti_tsc_dt_ids[] = {
549 { .compatible = "ti,am3359-tsc", },
550 { }
551};
552MODULE_DEVICE_TABLE(of, ti_tsc_dt_ids);
553
554static struct platform_driver ti_tsc_driver = {
555 .probe = titsc_probe,
556 .remove = titsc_remove,
557 .driver = {
558 .name = "TI-am335x-tsc",
559 .pm = &titsc_pm_ops,
560 .of_match_table = ti_tsc_dt_ids,
561 },
562};
563module_platform_driver(ti_tsc_driver);
564
565MODULE_DESCRIPTION("TI touchscreen controller driver");
566MODULE_AUTHOR("Rachna Patil <rachna@ti.com>");
567MODULE_LICENSE("GPL");