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mfd: wm8350-i2c: Make sure the i2c regmap functions are compiled
[linux/fpc-iii.git] / drivers / input / touchscreen / ti_am335x_tsc.c
blobe1c5300cacfc2044f83175dccffd864a8bd01fbc
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/init.h>
18 #include <linux/kernel.h>
19 #include <linux/err.h>
20 #include <linux/module.h>
21 #include <linux/input.h>
22 #include <linux/slab.h>
23 #include <linux/interrupt.h>
24 #include <linux/clk.h>
25 #include <linux/platform_device.h>
26 #include <linux/io.h>
27 #include <linux/delay.h>
28 #include <linux/of.h>
29 #include <linux/of_device.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 };
56
57 static unsigned int titsc_readl(struct titsc *ts, unsigned int reg)
58 {
59 return readl(ts->mfd_tscadc->tscadc_base + reg);
60 }
61
62 static void titsc_writel(struct titsc *tsc, unsigned int reg,
63 unsigned int val)
64 {
65 writel(val, tsc->mfd_tscadc->tscadc_base + reg);
66 }
67
68 static int titsc_config_wires(struct titsc *ts_dev)
69 {
70 u32 analog_line[4];
71 u32 wire_order[4];
72 int i, bit_cfg;
73
74 for (i = 0; i < 4; i++) {
75 /*
76 * Get the order in which TSC wires are attached
77 * w.r.t. each of the analog input lines on the EVM.
78 */
79 analog_line[i] = (ts_dev->config_inp[i] & 0xF0) >> 4;
80 wire_order[i] = ts_dev->config_inp[i] & 0x0F;
81 if (WARN_ON(analog_line[i] > 7))
82 return -EINVAL;
83 if (WARN_ON(wire_order[i] > ARRAY_SIZE(config_pins)))
84 return -EINVAL;
85 }
86
87 for (i = 0; i < 4; i++) {
88 int an_line;
89 int wi_order;
90
91 an_line = analog_line[i];
92 wi_order = wire_order[i];
93 bit_cfg = config_pins[wi_order];
94 if (bit_cfg == 0)
95 return -EINVAL;
96 switch (wi_order) {
97 case 0:
98 ts_dev->bit_xp = bit_cfg;
99 ts_dev->inp_xp = an_line;
100 break;
101
102 case 1:
103 ts_dev->bit_xn = bit_cfg;
104 ts_dev->inp_xn = an_line;
105 break;
106
107 case 2:
108 ts_dev->bit_yp = bit_cfg;
109 ts_dev->inp_yp = an_line;
110 break;
111 case 3:
112 ts_dev->bit_yn = bit_cfg;
113 ts_dev->inp_yn = an_line;
114 break;
115 }
116 }
117 return 0;
118 }
119
120 static void titsc_step_config(struct titsc *ts_dev)
121 {
122 unsigned int config;
123 int i;
124 int end_step;
125 u32 stepenable;
126
127 config = STEPCONFIG_MODE_HWSYNC |
128 STEPCONFIG_AVG_16 | ts_dev->bit_xp;
129 switch (ts_dev->wires) {
130 case 4:
131 config |= STEPCONFIG_INP(ts_dev->inp_yp) | ts_dev->bit_xn;
132 break;
133 case 5:
134 config |= ts_dev->bit_yn |
135 STEPCONFIG_INP_AN4 | ts_dev->bit_xn |
136 ts_dev->bit_yp;
137 break;
138 case 8:
139 config |= STEPCONFIG_INP(ts_dev->inp_yp) | ts_dev->bit_xn;
140 break;
141 }
142
143 /* 1 … coordinate_readouts is for X */
144 end_step = ts_dev->coordinate_readouts;
145 for (i = 0; i < end_step; i++) {
146 titsc_writel(ts_dev, REG_STEPCONFIG(i), config);
147 titsc_writel(ts_dev, REG_STEPDELAY(i), STEPCONFIG_OPENDLY);
148 }
149
150 config = 0;
151 config = STEPCONFIG_MODE_HWSYNC |
152 STEPCONFIG_AVG_16 | ts_dev->bit_yn |
153 STEPCONFIG_INM_ADCREFM;
154 switch (ts_dev->wires) {
155 case 4:
156 config |= ts_dev->bit_yp | STEPCONFIG_INP(ts_dev->inp_xp);
157 break;
158 case 5:
159 config |= ts_dev->bit_xp | STEPCONFIG_INP_AN4 |
160 ts_dev->bit_xn | ts_dev->bit_yp;
161 break;
162 case 8:
163 config |= ts_dev->bit_yp | STEPCONFIG_INP(ts_dev->inp_xp);
164 break;
165 }
166
167 /* coordinate_readouts … coordinate_readouts * 2 is for Y */
168 end_step = ts_dev->coordinate_readouts * 2;
169 for (i = ts_dev->coordinate_readouts; i < end_step; i++) {
170 titsc_writel(ts_dev, REG_STEPCONFIG(i), config);
171 titsc_writel(ts_dev, REG_STEPDELAY(i), STEPCONFIG_OPENDLY);
172 }
173
174 /* Charge step configuration */
175 config = ts_dev->bit_xp | ts_dev->bit_yn |
176 STEPCHARGE_RFP_XPUL | STEPCHARGE_RFM_XNUR |
177 STEPCHARGE_INM_AN1 | STEPCHARGE_INP(ts_dev->inp_yp);
178
179 titsc_writel(ts_dev, REG_CHARGECONFIG, config);
180 titsc_writel(ts_dev, REG_CHARGEDELAY, CHARGEDLY_OPENDLY);
181
182 /* coordinate_readouts * 2 … coordinate_readouts * 2 + 2 is for Z */
183 config = STEPCONFIG_MODE_HWSYNC |
184 STEPCONFIG_AVG_16 | ts_dev->bit_yp |
185 ts_dev->bit_xn | STEPCONFIG_INM_ADCREFM |
186 STEPCONFIG_INP(ts_dev->inp_xp);
187 titsc_writel(ts_dev, REG_STEPCONFIG(end_step), config);
188 titsc_writel(ts_dev, REG_STEPDELAY(end_step),
189 STEPCONFIG_OPENDLY);
190
191 end_step++;
192 config |= STEPCONFIG_INP(ts_dev->inp_yn);
193 titsc_writel(ts_dev, REG_STEPCONFIG(end_step), config);
194 titsc_writel(ts_dev, REG_STEPDELAY(end_step),
195 STEPCONFIG_OPENDLY);
196
197 /* The steps1 … end and bit 0 for TS_Charge */
198 stepenable = (1 << (end_step + 2)) - 1;
199 am335x_tsc_se_set(ts_dev->mfd_tscadc, stepenable);
200 }
201
202 static void titsc_read_coordinates(struct titsc *ts_dev,
203 u32 *x, u32 *y, u32 *z1, u32 *z2)
204 {
205 unsigned int fifocount = titsc_readl(ts_dev, REG_FIFO0CNT);
206 unsigned int prev_val_x = ~0, prev_val_y = ~0;
207 unsigned int prev_diff_x = ~0, prev_diff_y = ~0;
208 unsigned int read, diff;
209 unsigned int i, channel;
210 unsigned int creads = ts_dev->coordinate_readouts;
211
212 *z1 = *z2 = 0;
213 if (fifocount % (creads * 2 + 2))
214 fifocount -= fifocount % (creads * 2 + 2);
215 /*
216 * Delta filter is used to remove large variations in sampled
217 * values from ADC. The filter tries to predict where the next
218 * coordinate could be. This is done by taking a previous
219 * coordinate and subtracting it form current one. Further the
220 * algorithm compares the difference with that of a present value,
221 * if true the value is reported to the sub system.
222 */
223 for (i = 0; i < fifocount; i++) {
224 read = titsc_readl(ts_dev, REG_FIFO0);
225
226 channel = (read & 0xf0000) >> 16;
227 read &= 0xfff;
228 if (channel < creads) {
229 diff = abs(read - prev_val_x);
230 if (diff < prev_diff_x) {
231 prev_diff_x = diff;
232 *x = read;
233 }
234 prev_val_x = read;
235
236 } else if (channel < creads * 2) {
237 diff = abs(read - prev_val_y);
238 if (diff < prev_diff_y) {
239 prev_diff_y = diff;
240 *y = read;
241 }
242 prev_val_y = read;
243
244 } else if (channel < creads * 2 + 1) {
245 *z1 = read;
246
247 } else if (channel < creads * 2 + 2) {
248 *z2 = read;
249 }
250 }
251 }
252
253 static irqreturn_t titsc_irq(int irq, void *dev)
254 {
255 struct titsc *ts_dev = dev;
256 struct input_dev *input_dev = ts_dev->input;
257 unsigned int status, irqclr = 0;
258 unsigned int x = 0, y = 0;
259 unsigned int z1, z2, z;
260 unsigned int fsm;
261
262 status = titsc_readl(ts_dev, REG_IRQSTATUS);
263 if (status & IRQENB_FIFO0THRES) {
264
265 titsc_read_coordinates(ts_dev, &x, &y, &z1, &z2);
266
267 if (ts_dev->pen_down && z1 != 0 && z2 != 0) {
268 /*
269 * Calculate pressure using formula
270 * Resistance(touch) = x plate resistance *
271 * x postion/4096 * ((z2 / z1) - 1)
272 */
273 z = z1 - z2;
274 z *= x;
275 z *= ts_dev->x_plate_resistance;
276 z /= z2;
277 z = (z + 2047) >> 12;
278
279 if (z <= MAX_12BIT) {
280 input_report_abs(input_dev, ABS_X, x);
281 input_report_abs(input_dev, ABS_Y, y);
282 input_report_abs(input_dev, ABS_PRESSURE, z);
283 input_report_key(input_dev, BTN_TOUCH, 1);
284 input_sync(input_dev);
285 }
286 }
287 irqclr |= IRQENB_FIFO0THRES;
288 }
289
290 /*
291 * Time for sequencer to settle, to read
292 * correct state of the sequencer.
293 */
294 udelay(SEQ_SETTLE);
295
296 status = titsc_readl(ts_dev, REG_RAWIRQSTATUS);
297 if (status & IRQENB_PENUP) {
298 /* Pen up event */
299 fsm = titsc_readl(ts_dev, REG_ADCFSM);
300 if (fsm == ADCFSM_STEPID) {
301 ts_dev->pen_down = false;
302 input_report_key(input_dev, BTN_TOUCH, 0);
303 input_report_abs(input_dev, ABS_PRESSURE, 0);
304 input_sync(input_dev);
305 } else {
306 ts_dev->pen_down = true;
307 }
308 irqclr |= IRQENB_PENUP;
309 }
310
311 if (status & IRQENB_HW_PEN) {
312
313 titsc_writel(ts_dev, REG_IRQWAKEUP, 0x00);
314 titsc_writel(ts_dev, REG_IRQCLR, IRQENB_HW_PEN);
315 }
316
317 if (irqclr) {
318 titsc_writel(ts_dev, REG_IRQSTATUS, irqclr);
319 am335x_tsc_se_update(ts_dev->mfd_tscadc);
320 return IRQ_HANDLED;
321 }
322 return IRQ_NONE;
323 }
324
325 static int titsc_parse_dt(struct platform_device *pdev,
326 struct titsc *ts_dev)
327 {
328 struct device_node *node = pdev->dev.of_node;
329 int err;
330
331 if (!node)
332 return -EINVAL;
333
334 err = of_property_read_u32(node, "ti,wires", &ts_dev->wires);
335 if (err < 0)
336 return err;
337 switch (ts_dev->wires) {
338 case 4:
339 case 5:
340 case 8:
341 break;
342 default:
343 return -EINVAL;
344 }
345
346 err = of_property_read_u32(node, "ti,x-plate-resistance",
347 &ts_dev->x_plate_resistance);
348 if (err < 0)
349 return err;
350
351 err = of_property_read_u32(node, "ti,coordiante-readouts",
352 &ts_dev->coordinate_readouts);
353 if (err < 0)
354 return err;
355
356 return of_property_read_u32_array(node, "ti,wire-config",
357 ts_dev->config_inp, ARRAY_SIZE(ts_dev->config_inp));
358 }
359
360 /*
361 * The functions for inserting/removing driver as a module.
362 */
363
364 static int titsc_probe(struct platform_device *pdev)
365 {
366 struct titsc *ts_dev;
367 struct input_dev *input_dev;
368 struct ti_tscadc_dev *tscadc_dev = ti_tscadc_dev_get(pdev);
369 int err;
370
371 /* Allocate memory for device */
372 ts_dev = kzalloc(sizeof(struct titsc), GFP_KERNEL);
373 input_dev = input_allocate_device();
374 if (!ts_dev || !input_dev) {
375 dev_err(&pdev->dev, "failed to allocate memory.\n");
376 err = -ENOMEM;
377 goto err_free_mem;
378 }
379
380 tscadc_dev->tsc = ts_dev;
381 ts_dev->mfd_tscadc = tscadc_dev;
382 ts_dev->input = input_dev;
383 ts_dev->irq = tscadc_dev->irq;
384
385 err = titsc_parse_dt(pdev, ts_dev);
386 if (err) {
387 dev_err(&pdev->dev, "Could not find valid DT data.\n");
388 goto err_free_mem;
389 }
390
391 err = request_irq(ts_dev->irq, titsc_irq,
392 0, pdev->dev.driver->name, ts_dev);
393 if (err) {
394 dev_err(&pdev->dev, "failed to allocate irq.\n");
395 goto err_free_mem;
396 }
397
398 titsc_writel(ts_dev, REG_IRQENABLE, IRQENB_FIFO0THRES);
399 err = titsc_config_wires(ts_dev);
400 if (err) {
401 dev_err(&pdev->dev, "wrong i/p wire configuration\n");
402 goto err_free_irq;
403 }
404 titsc_step_config(ts_dev);
405 titsc_writel(ts_dev, REG_FIFO0THR,
406 ts_dev->coordinate_readouts * 2 + 2 - 1);
407
408 input_dev->name = "ti-tsc";
409 input_dev->dev.parent = &pdev->dev;
410
411 input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
412 input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
413
414 input_set_abs_params(input_dev, ABS_X, 0, MAX_12BIT, 0, 0);
415 input_set_abs_params(input_dev, ABS_Y, 0, MAX_12BIT, 0, 0);
416 input_set_abs_params(input_dev, ABS_PRESSURE, 0, MAX_12BIT, 0, 0);
417
418 /* register to the input system */
419 err = input_register_device(input_dev);
420 if (err)
421 goto err_free_irq;
422
423 platform_set_drvdata(pdev, ts_dev);
424 return 0;
425
426 err_free_irq:
427 free_irq(ts_dev->irq, ts_dev);
428 err_free_mem:
429 input_free_device(input_dev);
430 kfree(ts_dev);
431 return err;
432 }
433
434 static int titsc_remove(struct platform_device *pdev)
435 {
436 struct titsc *ts_dev = platform_get_drvdata(pdev);
437 u32 steps;
438
439 free_irq(ts_dev->irq, ts_dev);
440
441 /* total steps followed by the enable mask */
442 steps = 2 * ts_dev->coordinate_readouts + 2;
443 steps = (1 << steps) - 1;
444 am335x_tsc_se_clr(ts_dev->mfd_tscadc, steps);
445
446 input_unregister_device(ts_dev->input);
447
448 kfree(ts_dev);
449 return 0;
450 }
451
452 #ifdef CONFIG_PM
453 static int titsc_suspend(struct device *dev)
454 {
455 struct titsc *ts_dev = dev_get_drvdata(dev);
456 struct ti_tscadc_dev *tscadc_dev;
457 unsigned int idle;
458
459 tscadc_dev = ti_tscadc_dev_get(to_platform_device(dev));
460 if (device_may_wakeup(tscadc_dev->dev)) {
461 idle = titsc_readl(ts_dev, REG_IRQENABLE);
462 titsc_writel(ts_dev, REG_IRQENABLE,
463 (idle | IRQENB_HW_PEN));
464 titsc_writel(ts_dev, REG_IRQWAKEUP, IRQWKUP_ENB);
465 }
466 return 0;
467 }
468
469 static int titsc_resume(struct device *dev)
470 {
471 struct titsc *ts_dev = dev_get_drvdata(dev);
472 struct ti_tscadc_dev *tscadc_dev;
473
474 tscadc_dev = ti_tscadc_dev_get(to_platform_device(dev));
475 if (device_may_wakeup(tscadc_dev->dev)) {
476 titsc_writel(ts_dev, REG_IRQWAKEUP,
477 0x00);
478 titsc_writel(ts_dev, REG_IRQCLR, IRQENB_HW_PEN);
479 }
480 titsc_step_config(ts_dev);
481 titsc_writel(ts_dev, REG_FIFO0THR,
482 ts_dev->coordinate_readouts * 2 + 2 - 1);
483 return 0;
484 }
485
486 static const struct dev_pm_ops titsc_pm_ops = {
487 .suspend = titsc_suspend,
488 .resume = titsc_resume,
489 };
490 #define TITSC_PM_OPS (&titsc_pm_ops)
491 #else
492 #define TITSC_PM_OPS NULL
493 #endif
494
495 static const struct of_device_id ti_tsc_dt_ids[] = {
496 { .compatible = "ti,am3359-tsc", },
497 { }
498 };
499 MODULE_DEVICE_TABLE(of, ti_tsc_dt_ids);
500
501 static struct platform_driver ti_tsc_driver = {
502 .probe = titsc_probe,
503 .remove = titsc_remove,
504 .driver = {
505 .name = "TI-am335x-tsc",
506 .owner = THIS_MODULE,
507 .pm = TITSC_PM_OPS,
508 .of_match_table = of_match_ptr(ti_tsc_dt_ids),
509 },
510 };
511 module_platform_driver(ti_tsc_driver);
512
513 MODULE_DESCRIPTION("TI touchscreen controller driver");
514 MODULE_AUTHOR("Rachna Patil <rachna@ti.com>");
515 MODULE_LICENSE("GPL");
Linux with added FPC-III support