2 * TI Touch Screen driver
4 * Copyright (C) 2011 Texas Instruments Incorporated - http://www.ti.com/
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.
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.
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>
26 #include <linux/delay.h>
28 #include <linux/of_device.h>
29 #include <linux/sort.h>
31 #include <linux/mfd/ti_am335x_tscadc.h>
33 #define ADCFSM_STEPID 0x10
34 #define SEQ_SETTLE 275
35 #define MAX_12BIT ((1 << 12) - 1)
37 #define TSC_IRQENB_MASK (IRQENB_FIFO0THRES | IRQENB_EOS | IRQENB_HW_PEN)
39 static const int config_pins[] = {
47 struct input_dev *input;
48 struct ti_tscadc_dev *mfd_tscadc;
52 unsigned int x_plate_resistance;
54 int coordinate_readouts;
56 u32 bit_xp, bit_xn, bit_yp, bit_yn;
57 u32 inp_xp, inp_xn, inp_yp, inp_yn;
62 static unsigned int titsc_readl(struct titsc *ts, unsigned int reg)
64 return readl(ts->mfd_tscadc->tscadc_base + reg);
67 static void titsc_writel(struct titsc *tsc, unsigned int reg,
70 writel(val, tsc->mfd_tscadc->tscadc_base + reg);
73 static int titsc_config_wires(struct titsc *ts_dev)
79 for (i = 0; i < 4; i++) {
81 * Get the order in which TSC wires are attached
82 * w.r.t. each of the analog input lines on the EVM.
84 analog_line[i] = (ts_dev->config_inp[i] & 0xF0) >> 4;
85 wire_order[i] = ts_dev->config_inp[i] & 0x0F;
86 if (WARN_ON(analog_line[i] > 7))
88 if (WARN_ON(wire_order[i] > ARRAY_SIZE(config_pins)))
92 for (i = 0; i < 4; i++) {
96 an_line = analog_line[i];
97 wi_order = wire_order[i];
98 bit_cfg = config_pins[wi_order];
103 ts_dev->bit_xp = bit_cfg;
104 ts_dev->inp_xp = an_line;
108 ts_dev->bit_xn = bit_cfg;
109 ts_dev->inp_xn = an_line;
113 ts_dev->bit_yp = bit_cfg;
114 ts_dev->inp_yp = an_line;
117 ts_dev->bit_yn = bit_cfg;
118 ts_dev->inp_yn = an_line;
125 static void titsc_step_config(struct titsc *ts_dev)
129 int end_step, first_step, tsc_steps;
132 config = STEPCONFIG_MODE_HWSYNC |
133 STEPCONFIG_AVG_16 | ts_dev->bit_xp;
134 switch (ts_dev->wires) {
136 config |= STEPCONFIG_INP(ts_dev->inp_yp) | ts_dev->bit_xn;
139 config |= ts_dev->bit_yn |
140 STEPCONFIG_INP_AN4 | ts_dev->bit_xn |
144 config |= STEPCONFIG_INP(ts_dev->inp_yp) | ts_dev->bit_xn;
148 tsc_steps = ts_dev->coordinate_readouts * 2 + 2;
149 first_step = TOTAL_STEPS - tsc_steps;
150 /* Steps 16 to 16-coordinate_readouts is for X */
151 end_step = first_step + tsc_steps;
152 for (i = end_step - ts_dev->coordinate_readouts; i < end_step; i++) {
153 titsc_writel(ts_dev, REG_STEPCONFIG(i), config);
154 titsc_writel(ts_dev, REG_STEPDELAY(i), STEPCONFIG_OPENDLY);
158 config = STEPCONFIG_MODE_HWSYNC |
159 STEPCONFIG_AVG_16 | ts_dev->bit_yn |
160 STEPCONFIG_INM_ADCREFM;
161 switch (ts_dev->wires) {
163 config |= ts_dev->bit_yp | STEPCONFIG_INP(ts_dev->inp_xp);
166 config |= ts_dev->bit_xp | STEPCONFIG_INP_AN4 |
167 STEPCONFIG_XNP | STEPCONFIG_YPN;
170 config |= ts_dev->bit_yp | STEPCONFIG_INP(ts_dev->inp_xp);
174 /* 1 ... coordinate_readouts is for Y */
175 end_step = first_step + ts_dev->coordinate_readouts;
176 for (i = first_step; i < end_step; i++) {
177 titsc_writel(ts_dev, REG_STEPCONFIG(i), config);
178 titsc_writel(ts_dev, REG_STEPDELAY(i), STEPCONFIG_OPENDLY);
181 /* Make CHARGECONFIG same as IDLECONFIG */
183 config = titsc_readl(ts_dev, REG_IDLECONFIG);
184 titsc_writel(ts_dev, REG_CHARGECONFIG, config);
185 titsc_writel(ts_dev, REG_CHARGEDELAY, ts_dev->charge_delay);
187 /* coordinate_readouts + 1 ... coordinate_readouts + 2 is for Z */
188 config = STEPCONFIG_MODE_HWSYNC |
189 STEPCONFIG_AVG_16 | ts_dev->bit_yp |
190 ts_dev->bit_xn | STEPCONFIG_INM_ADCREFM |
191 STEPCONFIG_INP(ts_dev->inp_xp);
192 titsc_writel(ts_dev, REG_STEPCONFIG(end_step), config);
193 titsc_writel(ts_dev, REG_STEPDELAY(end_step),
197 config |= STEPCONFIG_INP(ts_dev->inp_yn);
198 titsc_writel(ts_dev, REG_STEPCONFIG(end_step), config);
199 titsc_writel(ts_dev, REG_STEPDELAY(end_step),
202 /* The steps end ... end - readouts * 2 + 2 and bit 0 for TS_Charge */
204 for (i = 0; i < tsc_steps; i++)
205 stepenable |= 1 << (first_step + i + 1);
207 ts_dev->step_mask = stepenable;
208 am335x_tsc_se_set_cache(ts_dev->mfd_tscadc, ts_dev->step_mask);
211 static int titsc_cmp_coord(const void *a, const void *b)
213 return *(int *)a - *(int *)b;
216 static void titsc_read_coordinates(struct titsc *ts_dev,
217 u32 *x, u32 *y, u32 *z1, u32 *z2)
219 unsigned int yvals[7], xvals[7];
220 unsigned int i, xsum = 0, ysum = 0;
221 unsigned int creads = ts_dev->coordinate_readouts;
223 for (i = 0; i < creads; i++) {
224 yvals[i] = titsc_readl(ts_dev, REG_FIFO0);
228 *z1 = titsc_readl(ts_dev, REG_FIFO0);
230 *z2 = titsc_readl(ts_dev, REG_FIFO0);
233 for (i = 0; i < creads; i++) {
234 xvals[i] = titsc_readl(ts_dev, REG_FIFO0);
239 * If co-ordinates readouts is less than 4 then
240 * report the average. In case of 4 or more
241 * readouts, sort the co-ordinate samples, drop
242 * min and max values and report the average of
246 for (i = 0; i < creads; i++) {
253 sort(yvals, creads, sizeof(unsigned int),
254 titsc_cmp_coord, NULL);
255 sort(xvals, creads, sizeof(unsigned int),
256 titsc_cmp_coord, NULL);
257 for (i = 1; i < creads - 1; i++) {
268 static irqreturn_t titsc_irq(int irq, void *dev)
270 struct titsc *ts_dev = dev;
271 struct input_dev *input_dev = ts_dev->input;
272 unsigned int fsm, status, irqclr = 0;
273 unsigned int x = 0, y = 0;
274 unsigned int z1, z2, z;
276 status = titsc_readl(ts_dev, REG_RAWIRQSTATUS);
277 if (status & IRQENB_HW_PEN) {
278 ts_dev->pen_down = true;
279 irqclr |= IRQENB_HW_PEN;
280 pm_stay_awake(ts_dev->dev);
283 if (status & IRQENB_PENUP) {
284 fsm = titsc_readl(ts_dev, REG_ADCFSM);
285 if (fsm == ADCFSM_STEPID) {
286 ts_dev->pen_down = false;
287 input_report_key(input_dev, BTN_TOUCH, 0);
288 input_report_abs(input_dev, ABS_PRESSURE, 0);
289 input_sync(input_dev);
290 pm_relax(ts_dev->dev);
292 ts_dev->pen_down = true;
294 irqclr |= IRQENB_PENUP;
297 if (status & IRQENB_EOS)
298 irqclr |= IRQENB_EOS;
301 * ADC and touchscreen share the IRQ line.
302 * FIFO1 interrupts are used by ADC. Handle FIFO0 IRQs here only
304 if (status & IRQENB_FIFO0THRES) {
306 titsc_read_coordinates(ts_dev, &x, &y, &z1, &z2);
308 if (ts_dev->pen_down && z1 != 0 && z2 != 0) {
310 * Calculate pressure using formula
311 * Resistance(touch) = x plate resistance *
312 * x postion/4096 * ((z2 / z1) - 1)
316 z *= ts_dev->x_plate_resistance;
318 z = (z + 2047) >> 12;
320 if (z <= MAX_12BIT) {
321 input_report_abs(input_dev, ABS_X, x);
322 input_report_abs(input_dev, ABS_Y, y);
323 input_report_abs(input_dev, ABS_PRESSURE, z);
324 input_report_key(input_dev, BTN_TOUCH, 1);
325 input_sync(input_dev);
328 irqclr |= IRQENB_FIFO0THRES;
331 titsc_writel(ts_dev, REG_IRQSTATUS, irqclr);
332 if (status & IRQENB_EOS)
333 am335x_tsc_se_set_cache(ts_dev->mfd_tscadc,
340 static int titsc_parse_dt(struct platform_device *pdev,
341 struct titsc *ts_dev)
343 struct device_node *node = pdev->dev.of_node;
349 err = of_property_read_u32(node, "ti,wires", &ts_dev->wires);
352 switch (ts_dev->wires) {
361 err = of_property_read_u32(node, "ti,x-plate-resistance",
362 &ts_dev->x_plate_resistance);
367 * Try with the new binding first. If it fails, try again with
368 * bogus, miss-spelled version.
370 err = of_property_read_u32(node, "ti,coordinate-readouts",
371 &ts_dev->coordinate_readouts);
373 dev_warn(&pdev->dev, "please use 'ti,coordinate-readouts' instead\n");
374 err = of_property_read_u32(node, "ti,coordiante-readouts",
375 &ts_dev->coordinate_readouts);
381 if (ts_dev->coordinate_readouts <= 0) {
383 "invalid co-ordinate readouts, resetting it to 5\n");
384 ts_dev->coordinate_readouts = 5;
387 err = of_property_read_u32(node, "ti,charge-delay",
388 &ts_dev->charge_delay);
390 * If ti,charge-delay value is not specified, then use
391 * CHARGEDLY_OPENDLY as the default value.
394 ts_dev->charge_delay = CHARGEDLY_OPENDLY;
395 dev_warn(&pdev->dev, "ti,charge-delay not specified\n");
398 return of_property_read_u32_array(node, "ti,wire-config",
399 ts_dev->config_inp, ARRAY_SIZE(ts_dev->config_inp));
403 * The functions for inserting/removing driver as a module.
406 static int titsc_probe(struct platform_device *pdev)
408 struct titsc *ts_dev;
409 struct input_dev *input_dev;
410 struct ti_tscadc_dev *tscadc_dev = ti_tscadc_dev_get(pdev);
413 /* Allocate memory for device */
414 ts_dev = kzalloc(sizeof(*ts_dev), GFP_KERNEL);
415 input_dev = input_allocate_device();
416 if (!ts_dev || !input_dev) {
417 dev_err(&pdev->dev, "failed to allocate memory.\n");
422 tscadc_dev->tsc = ts_dev;
423 ts_dev->mfd_tscadc = tscadc_dev;
424 ts_dev->input = input_dev;
425 ts_dev->irq = tscadc_dev->irq;
426 ts_dev->dev = &pdev->dev;
428 err = titsc_parse_dt(pdev, ts_dev);
430 dev_err(&pdev->dev, "Could not find valid DT data.\n");
434 err = request_irq(ts_dev->irq, titsc_irq,
435 IRQF_SHARED, pdev->dev.driver->name, ts_dev);
437 dev_err(&pdev->dev, "failed to allocate irq.\n");
441 device_init_wakeup(&pdev->dev, true);
443 titsc_writel(ts_dev, REG_IRQSTATUS, TSC_IRQENB_MASK);
444 titsc_writel(ts_dev, REG_IRQENABLE, IRQENB_FIFO0THRES);
445 titsc_writel(ts_dev, REG_IRQENABLE, IRQENB_EOS);
446 err = titsc_config_wires(ts_dev);
448 dev_err(&pdev->dev, "wrong i/p wire configuration\n");
451 titsc_step_config(ts_dev);
452 titsc_writel(ts_dev, REG_FIFO0THR,
453 ts_dev->coordinate_readouts * 2 + 2 - 1);
455 input_dev->name = "ti-tsc";
456 input_dev->dev.parent = &pdev->dev;
458 input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
459 input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
461 input_set_abs_params(input_dev, ABS_X, 0, MAX_12BIT, 0, 0);
462 input_set_abs_params(input_dev, ABS_Y, 0, MAX_12BIT, 0, 0);
463 input_set_abs_params(input_dev, ABS_PRESSURE, 0, MAX_12BIT, 0, 0);
465 /* register to the input system */
466 err = input_register_device(input_dev);
470 platform_set_drvdata(pdev, ts_dev);
474 device_init_wakeup(&pdev->dev, false);
475 free_irq(ts_dev->irq, ts_dev);
477 input_free_device(input_dev);
482 static int titsc_remove(struct platform_device *pdev)
484 struct titsc *ts_dev = platform_get_drvdata(pdev);
487 device_init_wakeup(&pdev->dev, false);
488 free_irq(ts_dev->irq, ts_dev);
490 /* total steps followed by the enable mask */
491 steps = 2 * ts_dev->coordinate_readouts + 2;
492 steps = (1 << steps) - 1;
493 am335x_tsc_se_clr(ts_dev->mfd_tscadc, steps);
495 input_unregister_device(ts_dev->input);
501 static int __maybe_unused titsc_suspend(struct device *dev)
503 struct titsc *ts_dev = dev_get_drvdata(dev);
504 struct ti_tscadc_dev *tscadc_dev;
507 tscadc_dev = ti_tscadc_dev_get(to_platform_device(dev));
508 if (device_may_wakeup(dev)) {
509 titsc_writel(ts_dev, REG_IRQSTATUS, TSC_IRQENB_MASK);
510 idle = titsc_readl(ts_dev, REG_IRQENABLE);
511 titsc_writel(ts_dev, REG_IRQENABLE,
512 (idle | IRQENB_HW_PEN));
513 titsc_writel(ts_dev, REG_IRQWAKEUP, IRQWKUP_ENB);
518 static int __maybe_unused titsc_resume(struct device *dev)
520 struct titsc *ts_dev = dev_get_drvdata(dev);
521 struct ti_tscadc_dev *tscadc_dev;
523 tscadc_dev = ti_tscadc_dev_get(to_platform_device(dev));
524 if (device_may_wakeup(dev)) {
525 titsc_writel(ts_dev, REG_IRQWAKEUP,
527 titsc_writel(ts_dev, REG_IRQCLR, IRQENB_HW_PEN);
530 titsc_step_config(ts_dev);
531 titsc_writel(ts_dev, REG_FIFO0THR,
532 ts_dev->coordinate_readouts * 2 + 2 - 1);
536 static SIMPLE_DEV_PM_OPS(titsc_pm_ops, titsc_suspend, titsc_resume);
538 static const struct of_device_id ti_tsc_dt_ids[] = {
539 { .compatible = "ti,am3359-tsc", },
542 MODULE_DEVICE_TABLE(of, ti_tsc_dt_ids);
544 static struct platform_driver ti_tsc_driver = {
545 .probe = titsc_probe,
546 .remove = titsc_remove,
548 .name = "TI-am335x-tsc",
550 .of_match_table = ti_tsc_dt_ids,
553 module_platform_driver(ti_tsc_driver);
555 MODULE_DESCRIPTION("TI touchscreen controller driver");
556 MODULE_AUTHOR("Rachna Patil <rachna@ti.com>");
557 MODULE_LICENSE("GPL");