1// SPDX-License-Identifier: GPL-2.0
2//
3// Freescale i.MX6UL touchscreen controller driver
4//
5// Copyright (C) 2015 Freescale Semiconductor, Inc.
6
7#include <linux/errno.h>
8#include <linux/kernel.h>
9#include <linux/module.h>
10#include <linux/gpio/consumer.h>
11#include <linux/input.h>
12#include <linux/slab.h>
13#include <linux/completion.h>
14#include <linux/delay.h>
15#include <linux/of.h>
16#include <linux/interrupt.h>
17#include <linux/platform_device.h>
18#include <linux/clk.h>
19#include <linux/io.h>
20#include <linux/log2.h>
21
22/* ADC configuration registers field define */
23#define ADC_AIEN (0x1 << 7)
24#define ADC_CONV_DISABLE 0x1F
25#define ADC_AVGE (0x1 << 5)
26#define ADC_CAL (0x1 << 7)
27#define ADC_CALF 0x2
28#define ADC_12BIT_MODE (0x2 << 2)
29#define ADC_CONV_MODE_MASK (0x3 << 2)
30#define ADC_IPG_CLK 0x00
31#define ADC_INPUT_CLK_MASK 0x3
32#define ADC_CLK_DIV_8 (0x03 << 5)
33#define ADC_CLK_DIV_MASK (0x3 << 5)
34#define ADC_SHORT_SAMPLE_MODE (0x0 << 4)
35#define ADC_SAMPLE_MODE_MASK (0x1 << 4)
36#define ADC_HARDWARE_TRIGGER (0x1 << 13)
37#define ADC_AVGS_SHIFT 14
38#define ADC_AVGS_MASK (0x3 << 14)
39#define SELECT_CHANNEL_4 0x04
40#define SELECT_CHANNEL_1 0x01
41#define DISABLE_CONVERSION_INT (0x0 << 7)
42
43/* ADC registers */
44#define REG_ADC_HC0 0x00
45#define REG_ADC_HC1 0x04
46#define REG_ADC_HC2 0x08
47#define REG_ADC_HC3 0x0C
48#define REG_ADC_HC4 0x10
49#define REG_ADC_HS 0x14
50#define REG_ADC_R0 0x18
51#define REG_ADC_CFG 0x2C
52#define REG_ADC_GC 0x30
53#define REG_ADC_GS 0x34
54
55#define ADC_TIMEOUT msecs_to_jiffies(100)
56
57/* TSC registers */
58#define REG_TSC_BASIC_SETING 0x00
59#define REG_TSC_PRE_CHARGE_TIME 0x10
60#define REG_TSC_FLOW_CONTROL 0x20
61#define REG_TSC_MEASURE_VALUE 0x30
62#define REG_TSC_INT_EN 0x40
63#define REG_TSC_INT_SIG_EN 0x50
64#define REG_TSC_INT_STATUS 0x60
65#define REG_TSC_DEBUG_MODE 0x70
66#define REG_TSC_DEBUG_MODE2 0x80
67
68/* TSC configuration registers field define */
69#define DETECT_4_WIRE_MODE (0x0 << 4)
70#define AUTO_MEASURE 0x1
71#define MEASURE_SIGNAL 0x1
72#define DETECT_SIGNAL (0x1 << 4)
73#define VALID_SIGNAL (0x1 << 8)
74#define MEASURE_INT_EN 0x1
75#define MEASURE_SIG_EN 0x1
76#define VALID_SIG_EN (0x1 << 8)
77#define DE_GLITCH_2 (0x2 << 29)
78#define START_SENSE (0x1 << 12)
79#define TSC_DISABLE (0x1 << 16)
80#define DETECT_MODE 0x2
81
82struct imx6ul_tsc {
83 struct device *dev;
84 struct input_dev *input;
85 void __iomem *tsc_regs;
86 void __iomem *adc_regs;
87 struct clk *tsc_clk;
88 struct clk *adc_clk;
89 struct gpio_desc *xnur_gpio;
90
91 u32 measure_delay_time;
92 u32 pre_charge_time;
93 bool average_enable;
94 u32 average_select;
95
96 struct completion completion;
97};
98
99/*
100 * TSC module need ADC to get the measure value. So
101 * before config TSC, we should initialize ADC module.
102 */
103static int imx6ul_adc_init(struct imx6ul_tsc *tsc)
104{
105 u32 adc_hc = 0;
106 u32 adc_gc;
107 u32 adc_gs;
108 u32 adc_cfg;
109 unsigned long timeout;
110
111 reinit_completion(x: &tsc->completion);
112
113 adc_cfg = readl(addr: tsc->adc_regs + REG_ADC_CFG);
114 adc_cfg &= ~(ADC_CONV_MODE_MASK | ADC_INPUT_CLK_MASK);
115 adc_cfg |= ADC_12BIT_MODE | ADC_IPG_CLK;
116 adc_cfg &= ~(ADC_CLK_DIV_MASK | ADC_SAMPLE_MODE_MASK);
117 adc_cfg |= ADC_CLK_DIV_8 | ADC_SHORT_SAMPLE_MODE;
118 if (tsc->average_enable) {
119 adc_cfg &= ~ADC_AVGS_MASK;
120 adc_cfg |= (tsc->average_select) << ADC_AVGS_SHIFT;
121 }
122 adc_cfg &= ~ADC_HARDWARE_TRIGGER;
123 writel(val: adc_cfg, addr: tsc->adc_regs + REG_ADC_CFG);
124
125 /* enable calibration interrupt */
126 adc_hc |= ADC_AIEN;
127 adc_hc |= ADC_CONV_DISABLE;
128 writel(val: adc_hc, addr: tsc->adc_regs + REG_ADC_HC0);
129
130 /* start ADC calibration */
131 adc_gc = readl(addr: tsc->adc_regs + REG_ADC_GC);
132 adc_gc |= ADC_CAL;
133 if (tsc->average_enable)
134 adc_gc |= ADC_AVGE;
135 writel(val: adc_gc, addr: tsc->adc_regs + REG_ADC_GC);
136
137 timeout = wait_for_completion_timeout
138 (x: &tsc->completion, ADC_TIMEOUT);
139 if (timeout == 0) {
140 dev_err(tsc->dev, "Timeout for adc calibration\n");
141 return -ETIMEDOUT;
142 }
143
144 adc_gs = readl(addr: tsc->adc_regs + REG_ADC_GS);
145 if (adc_gs & ADC_CALF) {
146 dev_err(tsc->dev, "ADC calibration failed\n");
147 return -EINVAL;
148 }
149
150 /* TSC need the ADC work in hardware trigger */
151 adc_cfg = readl(addr: tsc->adc_regs + REG_ADC_CFG);
152 adc_cfg |= ADC_HARDWARE_TRIGGER;
153 writel(val: adc_cfg, addr: tsc->adc_regs + REG_ADC_CFG);
154
155 return 0;
156}
157
158/*
159 * This is a TSC workaround. Currently TSC misconnect two
160 * ADC channels, this function remap channel configure for
161 * hardware trigger.
162 */
163static void imx6ul_tsc_channel_config(struct imx6ul_tsc *tsc)
164{
165 u32 adc_hc0, adc_hc1, adc_hc2, adc_hc3, adc_hc4;
166
167 adc_hc0 = DISABLE_CONVERSION_INT;
168 writel(val: adc_hc0, addr: tsc->adc_regs + REG_ADC_HC0);
169
170 adc_hc1 = DISABLE_CONVERSION_INT | SELECT_CHANNEL_4;
171 writel(val: adc_hc1, addr: tsc->adc_regs + REG_ADC_HC1);
172
173 adc_hc2 = DISABLE_CONVERSION_INT;
174 writel(val: adc_hc2, addr: tsc->adc_regs + REG_ADC_HC2);
175
176 adc_hc3 = DISABLE_CONVERSION_INT | SELECT_CHANNEL_1;
177 writel(val: adc_hc3, addr: tsc->adc_regs + REG_ADC_HC3);
178
179 adc_hc4 = DISABLE_CONVERSION_INT;
180 writel(val: adc_hc4, addr: tsc->adc_regs + REG_ADC_HC4);
181}
182
183/*
184 * TSC setting, confige the pre-charge time and measure delay time.
185 * different touch screen may need different pre-charge time and
186 * measure delay time.
187 */
188static void imx6ul_tsc_set(struct imx6ul_tsc *tsc)
189{
190 u32 basic_setting = 0;
191 u32 start;
192
193 basic_setting |= tsc->measure_delay_time << 8;
194 basic_setting |= DETECT_4_WIRE_MODE | AUTO_MEASURE;
195 writel(val: basic_setting, addr: tsc->tsc_regs + REG_TSC_BASIC_SETING);
196
197 writel(DE_GLITCH_2, addr: tsc->tsc_regs + REG_TSC_DEBUG_MODE2);
198
199 writel(val: tsc->pre_charge_time, addr: tsc->tsc_regs + REG_TSC_PRE_CHARGE_TIME);
200 writel(MEASURE_INT_EN, addr: tsc->tsc_regs + REG_TSC_INT_EN);
201 writel(MEASURE_SIG_EN | VALID_SIG_EN,
202 addr: tsc->tsc_regs + REG_TSC_INT_SIG_EN);
203
204 /* start sense detection */
205 start = readl(addr: tsc->tsc_regs + REG_TSC_FLOW_CONTROL);
206 start |= START_SENSE;
207 start &= ~TSC_DISABLE;
208 writel(val: start, addr: tsc->tsc_regs + REG_TSC_FLOW_CONTROL);
209}
210
211static int imx6ul_tsc_init(struct imx6ul_tsc *tsc)
212{
213 int err;
214
215 err = imx6ul_adc_init(tsc);
216 if (err)
217 return err;
218 imx6ul_tsc_channel_config(tsc);
219 imx6ul_tsc_set(tsc);
220
221 return 0;
222}
223
224static void imx6ul_tsc_disable(struct imx6ul_tsc *tsc)
225{
226 u32 tsc_flow;
227 u32 adc_cfg;
228
229 /* TSC controller enters to idle status */
230 tsc_flow = readl(addr: tsc->tsc_regs + REG_TSC_FLOW_CONTROL);
231 tsc_flow |= TSC_DISABLE;
232 writel(val: tsc_flow, addr: tsc->tsc_regs + REG_TSC_FLOW_CONTROL);
233
234 /* ADC controller enters to stop mode */
235 adc_cfg = readl(addr: tsc->adc_regs + REG_ADC_HC0);
236 adc_cfg |= ADC_CONV_DISABLE;
237 writel(val: adc_cfg, addr: tsc->adc_regs + REG_ADC_HC0);
238}
239
240/* Delay some time (max 2ms), wait the pre-charge done. */
241static bool tsc_wait_detect_mode(struct imx6ul_tsc *tsc)
242{
243 unsigned long timeout = jiffies + msecs_to_jiffies(m: 2);
244 u32 state_machine;
245 u32 debug_mode2;
246
247 do {
248 if (time_after(jiffies, timeout))
249 return false;
250
251 usleep_range(min: 200, max: 400);
252 debug_mode2 = readl(addr: tsc->tsc_regs + REG_TSC_DEBUG_MODE2);
253 state_machine = (debug_mode2 >> 20) & 0x7;
254 } while (state_machine != DETECT_MODE);
255
256 usleep_range(min: 200, max: 400);
257 return true;
258}
259
260static irqreturn_t tsc_irq_fn(int irq, void *dev_id)
261{
262 struct imx6ul_tsc *tsc = dev_id;
263 u32 status;
264 u32 value;
265 u32 x, y;
266 u32 start;
267
268 status = readl(addr: tsc->tsc_regs + REG_TSC_INT_STATUS);
269
270 /* write 1 to clear the bit measure-signal */
271 writel(MEASURE_SIGNAL | DETECT_SIGNAL,
272 addr: tsc->tsc_regs + REG_TSC_INT_STATUS);
273
274 /* It's a HW self-clean bit. Set this bit and start sense detection */
275 start = readl(addr: tsc->tsc_regs + REG_TSC_FLOW_CONTROL);
276 start |= START_SENSE;
277 writel(val: start, addr: tsc->tsc_regs + REG_TSC_FLOW_CONTROL);
278
279 if (status & MEASURE_SIGNAL) {
280 value = readl(addr: tsc->tsc_regs + REG_TSC_MEASURE_VALUE);
281 x = (value >> 16) & 0x0fff;
282 y = value & 0x0fff;
283
284 /*
285 * In detect mode, we can get the xnur gpio value,
286 * otherwise assume contact is stiull active.
287 */
288 if (!tsc_wait_detect_mode(tsc) ||
289 gpiod_get_value_cansleep(desc: tsc->xnur_gpio)) {
290 input_report_key(dev: tsc->input, BTN_TOUCH, value: 1);
291 input_report_abs(dev: tsc->input, ABS_X, value: x);
292 input_report_abs(dev: tsc->input, ABS_Y, value: y);
293 } else {
294 input_report_key(dev: tsc->input, BTN_TOUCH, value: 0);
295 }
296
297 input_sync(dev: tsc->input);
298 }
299
300 return IRQ_HANDLED;
301}
302
303static irqreturn_t adc_irq_fn(int irq, void *dev_id)
304{
305 struct imx6ul_tsc *tsc = dev_id;
306 u32 coco;
307
308 coco = readl(addr: tsc->adc_regs + REG_ADC_HS);
309 if (coco & 0x01) {
310 readl(addr: tsc->adc_regs + REG_ADC_R0);
311 complete(&tsc->completion);
312 }
313
314 return IRQ_HANDLED;
315}
316
317static int imx6ul_tsc_start(struct imx6ul_tsc *tsc)
318{
319 int err;
320
321 err = clk_prepare_enable(clk: tsc->adc_clk);
322 if (err) {
323 dev_err(tsc->dev,
324 "Could not prepare or enable the adc clock: %d\n",
325 err);
326 return err;
327 }
328
329 err = clk_prepare_enable(clk: tsc->tsc_clk);
330 if (err) {
331 dev_err(tsc->dev,
332 "Could not prepare or enable the tsc clock: %d\n",
333 err);
334 goto disable_adc_clk;
335 }
336
337 err = imx6ul_tsc_init(tsc);
338 if (err)
339 goto disable_tsc_clk;
340
341 return 0;
342
343disable_tsc_clk:
344 clk_disable_unprepare(clk: tsc->tsc_clk);
345disable_adc_clk:
346 clk_disable_unprepare(clk: tsc->adc_clk);
347 return err;
348}
349
350static void imx6ul_tsc_stop(struct imx6ul_tsc *tsc)
351{
352 imx6ul_tsc_disable(tsc);
353
354 clk_disable_unprepare(clk: tsc->tsc_clk);
355 clk_disable_unprepare(clk: tsc->adc_clk);
356}
357
358
359static int imx6ul_tsc_open(struct input_dev *input_dev)
360{
361 struct imx6ul_tsc *tsc = input_get_drvdata(dev: input_dev);
362
363 return imx6ul_tsc_start(tsc);
364}
365
366static void imx6ul_tsc_close(struct input_dev *input_dev)
367{
368 struct imx6ul_tsc *tsc = input_get_drvdata(dev: input_dev);
369
370 imx6ul_tsc_stop(tsc);
371}
372
373static int imx6ul_tsc_probe(struct platform_device *pdev)
374{
375 struct device_node *np = pdev->dev.of_node;
376 struct imx6ul_tsc *tsc;
377 struct input_dev *input_dev;
378 int err;
379 int tsc_irq;
380 int adc_irq;
381 u32 average_samples;
382
383 tsc = devm_kzalloc(dev: &pdev->dev, size: sizeof(*tsc), GFP_KERNEL);
384 if (!tsc)
385 return -ENOMEM;
386
387 input_dev = devm_input_allocate_device(&pdev->dev);
388 if (!input_dev)
389 return -ENOMEM;
390
391 input_dev->name = "iMX6UL Touchscreen Controller";
392 input_dev->id.bustype = BUS_HOST;
393
394 input_dev->open = imx6ul_tsc_open;
395 input_dev->close = imx6ul_tsc_close;
396
397 input_set_capability(dev: input_dev, EV_KEY, BTN_TOUCH);
398 input_set_abs_params(dev: input_dev, ABS_X, min: 0, max: 0xFFF, fuzz: 0, flat: 0);
399 input_set_abs_params(dev: input_dev, ABS_Y, min: 0, max: 0xFFF, fuzz: 0, flat: 0);
400
401 input_set_drvdata(dev: input_dev, data: tsc);
402
403 tsc->dev = &pdev->dev;
404 tsc->input = input_dev;
405 init_completion(x: &tsc->completion);
406
407 tsc->xnur_gpio = devm_gpiod_get(dev: &pdev->dev, con_id: "xnur", flags: GPIOD_IN);
408 if (IS_ERR(ptr: tsc->xnur_gpio)) {
409 err = PTR_ERR(ptr: tsc->xnur_gpio);
410 dev_err(&pdev->dev,
411 "failed to request GPIO tsc_X- (xnur): %d\n", err);
412 return err;
413 }
414
415 tsc->tsc_regs = devm_platform_ioremap_resource(pdev, index: 0);
416 if (IS_ERR(ptr: tsc->tsc_regs)) {
417 err = PTR_ERR(ptr: tsc->tsc_regs);
418 dev_err(&pdev->dev, "failed to remap tsc memory: %d\n", err);
419 return err;
420 }
421
422 tsc->adc_regs = devm_platform_ioremap_resource(pdev, index: 1);
423 if (IS_ERR(ptr: tsc->adc_regs)) {
424 err = PTR_ERR(ptr: tsc->adc_regs);
425 dev_err(&pdev->dev, "failed to remap adc memory: %d\n", err);
426 return err;
427 }
428
429 tsc->tsc_clk = devm_clk_get(dev: &pdev->dev, id: "tsc");
430 if (IS_ERR(ptr: tsc->tsc_clk)) {
431 err = PTR_ERR(ptr: tsc->tsc_clk);
432 dev_err(&pdev->dev, "failed getting tsc clock: %d\n", err);
433 return err;
434 }
435
436 tsc->adc_clk = devm_clk_get(dev: &pdev->dev, id: "adc");
437 if (IS_ERR(ptr: tsc->adc_clk)) {
438 err = PTR_ERR(ptr: tsc->adc_clk);
439 dev_err(&pdev->dev, "failed getting adc clock: %d\n", err);
440 return err;
441 }
442
443 tsc_irq = platform_get_irq(pdev, 0);
444 if (tsc_irq < 0)
445 return tsc_irq;
446
447 adc_irq = platform_get_irq(pdev, 1);
448 if (adc_irq < 0)
449 return adc_irq;
450
451 err = devm_request_threaded_irq(dev: tsc->dev, irq: tsc_irq,
452 NULL, thread_fn: tsc_irq_fn, IRQF_ONESHOT,
453 devname: dev_name(dev: &pdev->dev), dev_id: tsc);
454 if (err) {
455 dev_err(&pdev->dev,
456 "failed requesting tsc irq %d: %d\n",
457 tsc_irq, err);
458 return err;
459 }
460
461 err = devm_request_irq(dev: tsc->dev, irq: adc_irq, handler: adc_irq_fn, irqflags: 0,
462 devname: dev_name(dev: &pdev->dev), dev_id: tsc);
463 if (err) {
464 dev_err(&pdev->dev,
465 "failed requesting adc irq %d: %d\n",
466 adc_irq, err);
467 return err;
468 }
469
470 err = of_property_read_u32(np, propname: "measure-delay-time",
471 out_value: &tsc->measure_delay_time);
472 if (err)
473 tsc->measure_delay_time = 0xffff;
474
475 err = of_property_read_u32(np, propname: "pre-charge-time",
476 out_value: &tsc->pre_charge_time);
477 if (err)
478 tsc->pre_charge_time = 0xfff;
479
480 err = of_property_read_u32(np, propname: "touchscreen-average-samples",
481 out_value: &average_samples);
482 if (err)
483 average_samples = 1;
484
485 switch (average_samples) {
486 case 1:
487 tsc->average_enable = false;
488 tsc->average_select = 0; /* value unused; initialize anyway */
489 break;
490 case 4:
491 case 8:
492 case 16:
493 case 32:
494 tsc->average_enable = true;
495 tsc->average_select = ilog2(average_samples) - 2;
496 break;
497 default:
498 dev_err(&pdev->dev,
499 "touchscreen-average-samples (%u) must be 1, 4, 8, 16 or 32\n",
500 average_samples);
501 return -EINVAL;
502 }
503
504 err = input_register_device(tsc->input);
505 if (err) {
506 dev_err(&pdev->dev,
507 "failed to register input device: %d\n", err);
508 return err;
509 }
510
511 platform_set_drvdata(pdev, data: tsc);
512 return 0;
513}
514
515static int imx6ul_tsc_suspend(struct device *dev)
516{
517 struct platform_device *pdev = to_platform_device(dev);
518 struct imx6ul_tsc *tsc = platform_get_drvdata(pdev);
519 struct input_dev *input_dev = tsc->input;
520
521 mutex_lock(&input_dev->mutex);
522
523 if (input_device_enabled(dev: input_dev))
524 imx6ul_tsc_stop(tsc);
525
526 mutex_unlock(lock: &input_dev->mutex);
527
528 return 0;
529}
530
531static int imx6ul_tsc_resume(struct device *dev)
532{
533 struct platform_device *pdev = to_platform_device(dev);
534 struct imx6ul_tsc *tsc = platform_get_drvdata(pdev);
535 struct input_dev *input_dev = tsc->input;
536 int retval = 0;
537
538 mutex_lock(&input_dev->mutex);
539
540 if (input_device_enabled(dev: input_dev))
541 retval = imx6ul_tsc_start(tsc);
542
543 mutex_unlock(lock: &input_dev->mutex);
544
545 return retval;
546}
547
548static DEFINE_SIMPLE_DEV_PM_OPS(imx6ul_tsc_pm_ops,
549 imx6ul_tsc_suspend, imx6ul_tsc_resume);
550
551static const struct of_device_id imx6ul_tsc_match[] = {
552 { .compatible = "fsl,imx6ul-tsc", },
553 { /* sentinel */ }
554};
555MODULE_DEVICE_TABLE(of, imx6ul_tsc_match);
556
557static struct platform_driver imx6ul_tsc_driver = {
558 .driver = {
559 .name = "imx6ul-tsc",
560 .of_match_table = imx6ul_tsc_match,
561 .pm = pm_sleep_ptr(&imx6ul_tsc_pm_ops),
562 },
563 .probe = imx6ul_tsc_probe,
564};
565module_platform_driver(imx6ul_tsc_driver);
566
567MODULE_AUTHOR("Haibo Chen <haibo.chen@freescale.com>");
568MODULE_DESCRIPTION("Freescale i.MX6UL Touchscreen controller driver");
569MODULE_LICENSE("GPL v2");
570

source code of linux/drivers/input/touchscreen/imx6ul_tsc.c