1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Touchscreen driver for WM831x PMICs
4 *
5 * Copyright 2011 Wolfson Microelectronics plc.
6 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
7 */
8
9#include <linux/module.h>
10#include <linux/moduleparam.h>
11#include <linux/kernel.h>
12#include <linux/string.h>
13#include <linux/pm.h>
14#include <linux/input.h>
15#include <linux/interrupt.h>
16#include <linux/io.h>
17#include <linux/mfd/wm831x/core.h>
18#include <linux/mfd/wm831x/irq.h>
19#include <linux/mfd/wm831x/pdata.h>
20#include <linux/platform_device.h>
21#include <linux/slab.h>
22#include <linux/types.h>
23
24/*
25 * R16424 (0x4028) - Touch Control 1
26 */
27#define WM831X_TCH_ENA                          0x8000  /* TCH_ENA */
28#define WM831X_TCH_CVT_ENA                      0x4000  /* TCH_CVT_ENA */
29#define WM831X_TCH_SLPENA                       0x1000  /* TCH_SLPENA */
30#define WM831X_TCH_Z_ENA                        0x0400  /* TCH_Z_ENA */
31#define WM831X_TCH_Y_ENA                        0x0200  /* TCH_Y_ENA */
32#define WM831X_TCH_X_ENA                        0x0100  /* TCH_X_ENA */
33#define WM831X_TCH_DELAY_MASK                   0x00E0  /* TCH_DELAY - [7:5] */
34#define WM831X_TCH_DELAY_SHIFT                       5  /* TCH_DELAY - [7:5] */
35#define WM831X_TCH_DELAY_WIDTH                       3  /* TCH_DELAY - [7:5] */
36#define WM831X_TCH_RATE_MASK                    0x001F  /* TCH_RATE - [4:0] */
37#define WM831X_TCH_RATE_SHIFT                        0  /* TCH_RATE - [4:0] */
38#define WM831X_TCH_RATE_WIDTH                        5  /* TCH_RATE - [4:0] */
39
40/*
41 * R16425 (0x4029) - Touch Control 2
42 */
43#define WM831X_TCH_PD_WK                        0x2000  /* TCH_PD_WK */
44#define WM831X_TCH_5WIRE                        0x1000  /* TCH_5WIRE */
45#define WM831X_TCH_PDONLY                       0x0800  /* TCH_PDONLY */
46#define WM831X_TCH_ISEL                         0x0100  /* TCH_ISEL */
47#define WM831X_TCH_RPU_MASK                     0x000F  /* TCH_RPU - [3:0] */
48#define WM831X_TCH_RPU_SHIFT                         0  /* TCH_RPU - [3:0] */
49#define WM831X_TCH_RPU_WIDTH                         4  /* TCH_RPU - [3:0] */
50
51/*
52 * R16426-8 (0x402A-C) - Touch Data X/Y/X
53 */
54#define WM831X_TCH_PD                           0x8000  /* TCH_PD1 */
55#define WM831X_TCH_DATA_MASK                    0x0FFF  /* TCH_DATA - [11:0] */
56#define WM831X_TCH_DATA_SHIFT                        0  /* TCH_DATA - [11:0] */
57#define WM831X_TCH_DATA_WIDTH                       12  /* TCH_DATA - [11:0] */
58
59struct wm831x_ts {
60	struct input_dev *input_dev;
61	struct wm831x *wm831x;
62	unsigned int data_irq;
63	unsigned int pd_irq;
64	bool pressure;
65	bool pen_down;
66	struct work_struct pd_data_work;
67};
68
69static void wm831x_pd_data_work(struct work_struct *work)
70{
71	struct wm831x_ts *wm831x_ts =
72		container_of(work, struct wm831x_ts, pd_data_work);
73
74	if (wm831x_ts->pen_down) {
75		enable_irq(wm831x_ts->data_irq);
76		dev_dbg(wm831x_ts->wm831x->dev, "IRQ PD->DATA done\n");
77	} else {
78		enable_irq(wm831x_ts->pd_irq);
79		dev_dbg(wm831x_ts->wm831x->dev, "IRQ DATA->PD done\n");
80	}
81}
82
83static irqreturn_t wm831x_ts_data_irq(int irq, void *irq_data)
84{
85	struct wm831x_ts *wm831x_ts = irq_data;
86	struct wm831x *wm831x = wm831x_ts->wm831x;
87	static int data_types[] = { ABS_X, ABS_Y, ABS_PRESSURE };
88	u16 data[3];
89	int count;
90	int i, ret;
91
92	if (wm831x_ts->pressure)
93		count = 3;
94	else
95		count = 2;
96
97	wm831x_set_bits(wm831x, WM831X_INTERRUPT_STATUS_1,
98			WM831X_TCHDATA_EINT, WM831X_TCHDATA_EINT);
99
100	ret = wm831x_bulk_read(wm831x, WM831X_TOUCH_DATA_X, count,
101			       data);
102	if (ret != 0) {
103		dev_err(wm831x->dev, "Failed to read touch data: %d\n",
104			ret);
105		return IRQ_NONE;
106	}
107
108	/*
109	 * We get a pen down reading on every reading, report pen up if any
110	 * individual reading does so.
111	 */
112	wm831x_ts->pen_down = true;
113	for (i = 0; i < count; i++) {
114		if (!(data[i] & WM831X_TCH_PD)) {
115			wm831x_ts->pen_down = false;
116			continue;
117		}
118		input_report_abs(wm831x_ts->input_dev, data_types[i],
119				 data[i] & WM831X_TCH_DATA_MASK);
120	}
121
122	if (!wm831x_ts->pen_down) {
123		/* Switch from data to pen down */
124		dev_dbg(wm831x->dev, "IRQ DATA->PD\n");
125
126		disable_irq_nosync(wm831x_ts->data_irq);
127
128		/* Don't need data any more */
129		wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
130				WM831X_TCH_X_ENA | WM831X_TCH_Y_ENA |
131				WM831X_TCH_Z_ENA, 0);
132
133		/* Flush any final samples that arrived while reading */
134		wm831x_set_bits(wm831x, WM831X_INTERRUPT_STATUS_1,
135				WM831X_TCHDATA_EINT, WM831X_TCHDATA_EINT);
136
137		wm831x_bulk_read(wm831x, WM831X_TOUCH_DATA_X, count, data);
138
139		if (wm831x_ts->pressure)
140			input_report_abs(wm831x_ts->input_dev,
141					 ABS_PRESSURE, 0);
142
143		input_report_key(wm831x_ts->input_dev, BTN_TOUCH, 0);
144
145		schedule_work(&wm831x_ts->pd_data_work);
146	} else {
147		input_report_key(wm831x_ts->input_dev, BTN_TOUCH, 1);
148	}
149
150	input_sync(wm831x_ts->input_dev);
151
152	return IRQ_HANDLED;
153}
154
155static irqreturn_t wm831x_ts_pen_down_irq(int irq, void *irq_data)
156{
157	struct wm831x_ts *wm831x_ts = irq_data;
158	struct wm831x *wm831x = wm831x_ts->wm831x;
159	int ena = 0;
160
161	if (wm831x_ts->pen_down)
162		return IRQ_HANDLED;
163
164	disable_irq_nosync(wm831x_ts->pd_irq);
165
166	/* Start collecting data */
167	if (wm831x_ts->pressure)
168		ena |= WM831X_TCH_Z_ENA;
169
170	wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
171			WM831X_TCH_X_ENA | WM831X_TCH_Y_ENA | WM831X_TCH_Z_ENA,
172			WM831X_TCH_X_ENA | WM831X_TCH_Y_ENA | ena);
173
174	wm831x_set_bits(wm831x, WM831X_INTERRUPT_STATUS_1,
175			WM831X_TCHPD_EINT, WM831X_TCHPD_EINT);
176
177	wm831x_ts->pen_down = true;
178
179	/* Switch from pen down to data */
180	dev_dbg(wm831x->dev, "IRQ PD->DATA\n");
181	schedule_work(&wm831x_ts->pd_data_work);
182
183	return IRQ_HANDLED;
184}
185
186static int wm831x_ts_input_open(struct input_dev *idev)
187{
188	struct wm831x_ts *wm831x_ts = input_get_drvdata(idev);
189	struct wm831x *wm831x = wm831x_ts->wm831x;
190
191	wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
192			WM831X_TCH_ENA | WM831X_TCH_CVT_ENA |
193			WM831X_TCH_X_ENA | WM831X_TCH_Y_ENA |
194			WM831X_TCH_Z_ENA, WM831X_TCH_ENA);
195
196	wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
197			WM831X_TCH_CVT_ENA, WM831X_TCH_CVT_ENA);
198
199	return 0;
200}
201
202static void wm831x_ts_input_close(struct input_dev *idev)
203{
204	struct wm831x_ts *wm831x_ts = input_get_drvdata(idev);
205	struct wm831x *wm831x = wm831x_ts->wm831x;
206
207	/* Shut the controller down, disabling all other functionality too */
208	wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
209			WM831X_TCH_ENA | WM831X_TCH_X_ENA |
210			WM831X_TCH_Y_ENA | WM831X_TCH_Z_ENA, 0);
211
212	/* Make sure any pending IRQs are done, the above will prevent
213	 * new ones firing.
214	 */
215	synchronize_irq(wm831x_ts->data_irq);
216	synchronize_irq(wm831x_ts->pd_irq);
217
218	/* Make sure the IRQ completion work is quiesced */
219	flush_work(&wm831x_ts->pd_data_work);
220
221	/* If we ended up with the pen down then make sure we revert back
222	 * to pen detection state for the next time we start up.
223	 */
224	if (wm831x_ts->pen_down) {
225		disable_irq(wm831x_ts->data_irq);
226		enable_irq(wm831x_ts->pd_irq);
227		wm831x_ts->pen_down = false;
228	}
229}
230
231static int wm831x_ts_probe(struct platform_device *pdev)
232{
233	struct wm831x_ts *wm831x_ts;
234	struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
235	struct wm831x_pdata *core_pdata = dev_get_platdata(pdev->dev.parent);
236	struct wm831x_touch_pdata *pdata = NULL;
237	struct input_dev *input_dev;
238	int error, irqf;
239
240	if (core_pdata)
241		pdata = core_pdata->touch;
242
243	wm831x_ts = devm_kzalloc(&pdev->dev, sizeof(struct wm831x_ts),
244				 GFP_KERNEL);
245	input_dev = devm_input_allocate_device(&pdev->dev);
246	if (!wm831x_ts || !input_dev) {
247		error = -ENOMEM;
248		goto err_alloc;
249	}
250
251	wm831x_ts->wm831x = wm831x;
252	wm831x_ts->input_dev = input_dev;
253	INIT_WORK(&wm831x_ts->pd_data_work, wm831x_pd_data_work);
254
255	/*
256	 * If we have a direct IRQ use it, otherwise use the interrupt
257	 * from the WM831x IRQ controller.
258	 */
259	wm831x_ts->data_irq = wm831x_irq(wm831x,
260					 platform_get_irq_byname(pdev,
261								 "TCHDATA"));
262	if (pdata && pdata->data_irq)
263		wm831x_ts->data_irq = pdata->data_irq;
264
265	wm831x_ts->pd_irq = wm831x_irq(wm831x,
266				       platform_get_irq_byname(pdev, "TCHPD"));
267	if (pdata && pdata->pd_irq)
268		wm831x_ts->pd_irq = pdata->pd_irq;
269
270	if (pdata)
271		wm831x_ts->pressure = pdata->pressure;
272	else
273		wm831x_ts->pressure = true;
274
275	/* Five wire touchscreens can't report pressure */
276	if (pdata && pdata->fivewire) {
277		wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
278				WM831X_TCH_5WIRE, WM831X_TCH_5WIRE);
279
280		/* Pressure measurements are not possible for five wire mode */
281		WARN_ON(pdata->pressure && pdata->fivewire);
282		wm831x_ts->pressure = false;
283	} else {
284		wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
285				WM831X_TCH_5WIRE, 0);
286	}
287
288	if (pdata) {
289		switch (pdata->isel) {
290		default:
291			dev_err(&pdev->dev, "Unsupported ISEL setting: %d\n",
292				pdata->isel);
293			fallthrough;
294		case 200:
295		case 0:
296			wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
297					WM831X_TCH_ISEL, 0);
298			break;
299		case 400:
300			wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
301					WM831X_TCH_ISEL, WM831X_TCH_ISEL);
302			break;
303		}
304	}
305
306	wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
307			WM831X_TCH_PDONLY, 0);
308
309	/* Default to 96 samples/sec */
310	wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
311			WM831X_TCH_RATE_MASK, 6);
312
313	if (pdata && pdata->data_irqf)
314		irqf = pdata->data_irqf;
315	else
316		irqf = IRQF_TRIGGER_HIGH;
317
318	error = request_threaded_irq(wm831x_ts->data_irq,
319				     NULL, wm831x_ts_data_irq,
320				     irqf | IRQF_ONESHOT | IRQF_NO_AUTOEN,
321				     "Touchscreen data", wm831x_ts);
322	if (error) {
323		dev_err(&pdev->dev, "Failed to request data IRQ %d: %d\n",
324			wm831x_ts->data_irq, error);
325		goto err_alloc;
326	}
327
328	if (pdata && pdata->pd_irqf)
329		irqf = pdata->pd_irqf;
330	else
331		irqf = IRQF_TRIGGER_HIGH;
332
333	error = request_threaded_irq(wm831x_ts->pd_irq,
334				     NULL, wm831x_ts_pen_down_irq,
335				     irqf | IRQF_ONESHOT,
336				     "Touchscreen pen down", wm831x_ts);
337	if (error) {
338		dev_err(&pdev->dev, "Failed to request pen down IRQ %d: %d\n",
339			wm831x_ts->pd_irq, error);
340		goto err_data_irq;
341	}
342
343	/* set up touch configuration */
344	input_dev->name = "WM831x touchscreen";
345	input_dev->phys = "wm831x";
346	input_dev->open = wm831x_ts_input_open;
347	input_dev->close = wm831x_ts_input_close;
348
349	__set_bit(EV_ABS, input_dev->evbit);
350	__set_bit(EV_KEY, input_dev->evbit);
351	__set_bit(BTN_TOUCH, input_dev->keybit);
352
353	input_set_abs_params(input_dev, ABS_X, 0, 4095, 5, 0);
354	input_set_abs_params(input_dev, ABS_Y, 0, 4095, 5, 0);
355	if (wm831x_ts->pressure)
356		input_set_abs_params(input_dev, ABS_PRESSURE, 0, 4095, 5, 0);
357
358	input_set_drvdata(input_dev, wm831x_ts);
359	input_dev->dev.parent = &pdev->dev;
360
361	error = input_register_device(input_dev);
362	if (error)
363		goto err_pd_irq;
364
365	platform_set_drvdata(pdev, wm831x_ts);
366	return 0;
367
368err_pd_irq:
369	free_irq(wm831x_ts->pd_irq, wm831x_ts);
370err_data_irq:
371	free_irq(wm831x_ts->data_irq, wm831x_ts);
372err_alloc:
373
374	return error;
375}
376
377static void wm831x_ts_remove(struct platform_device *pdev)
378{
379	struct wm831x_ts *wm831x_ts = platform_get_drvdata(pdev);
380
381	free_irq(wm831x_ts->pd_irq, wm831x_ts);
382	free_irq(wm831x_ts->data_irq, wm831x_ts);
383}
384
385static struct platform_driver wm831x_ts_driver = {
386	.driver = {
387		.name = "wm831x-touch",
388	},
389	.probe = wm831x_ts_probe,
390	.remove_new = wm831x_ts_remove,
391};
392module_platform_driver(wm831x_ts_driver);
393
394/* Module information */
395MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
396MODULE_DESCRIPTION("WM831x PMIC touchscreen driver");
397MODULE_LICENSE("GPL");
398MODULE_ALIAS("platform:wm831x-touch");
399