1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (C) 2015 Broadcom Corporation
4 *
5 */
6 #include <linux/module.h>
7 #include <linux/init.h>
8 #include <linux/input.h>
9 #include <linux/delay.h>
10 #include <linux/interrupt.h>
11 #include <linux/keyboard.h>
12 #include <linux/platform_device.h>
13 #include <linux/slab.h>
14 #include <linux/of.h>
15 #include <asm/irq.h>
16 #include <linux/io.h>
17 #include <linux/clk.h>
18 #include <linux/serio.h>
19 #include <linux/mfd/syscon.h>
20 #include <linux/regmap.h>
21 
22 #define IPROC_TS_NAME "iproc-ts"
23 
24 #define PEN_DOWN_STATUS     1
25 #define PEN_UP_STATUS       0
26 
27 #define X_MIN               0
28 #define Y_MIN               0
29 #define X_MAX               0xFFF
30 #define Y_MAX               0xFFF
31 
32 /* Value given by controller for invalid coordinate. */
33 #define INVALID_COORD       0xFFFFFFFF
34 
35 /* Register offsets */
36 #define REGCTL1             0x00
37 #define REGCTL2             0x04
38 #define INTERRUPT_THRES     0x08
39 #define INTERRUPT_MASK      0x0c
40 
41 #define INTERRUPT_STATUS    0x10
42 #define CONTROLLER_STATUS   0x14
43 #define FIFO_DATA           0x18
44 #define FIFO_DATA_X_Y_MASK  0xFFFF
45 #define ANALOG_CONTROL      0x1c
46 
47 #define AUX_DATA            0x20
48 #define DEBOUNCE_CNTR_STAT  0x24
49 #define SCAN_CNTR_STAT      0x28
50 #define REM_CNTR_STAT       0x2c
51 
52 #define SETTLING_TIMER_STAT 0x30
53 #define SPARE_REG           0x34
54 #define SOFT_BYPASS_CONTROL 0x38
55 #define SOFT_BYPASS_DATA    0x3c
56 
57 
58 /* Bit values for INTERRUPT_MASK and INTERRUPT_STATUS regs */
59 #define TS_PEN_INTR_MASK        BIT(0)
60 #define TS_FIFO_INTR_MASK       BIT(2)
61 
62 /* Bit values for CONTROLLER_STATUS reg1 */
63 #define TS_PEN_DOWN             BIT(0)
64 
65 /* Shift values for control reg1 */
66 #define SCANNING_PERIOD_SHIFT   24
67 #define DEBOUNCE_TIMEOUT_SHIFT  16
68 #define SETTLING_TIMEOUT_SHIFT  8
69 #define TOUCH_TIMEOUT_SHIFT     0
70 
71 /* Shift values for coordinates from fifo */
72 #define X_COORD_SHIFT  0
73 #define Y_COORD_SHIFT  16
74 
75 /* Bit values for REGCTL2 */
76 #define TS_CONTROLLER_EN_BIT    BIT(16)
77 #define TS_CONTROLLER_AVGDATA_SHIFT 8
78 #define TS_CONTROLLER_AVGDATA_MASK (0x7 << TS_CONTROLLER_AVGDATA_SHIFT)
79 #define TS_CONTROLLER_PWR_LDO   BIT(5)
80 #define TS_CONTROLLER_PWR_ADC   BIT(4)
81 #define TS_CONTROLLER_PWR_BGP   BIT(3)
82 #define TS_CONTROLLER_PWR_TS    BIT(2)
83 #define TS_WIRE_MODE_BIT        BIT(1)
84 
85 #define dbg_reg(dev, priv, reg) \
86 do { \
87 	u32 val; \
88 	regmap_read(priv->regmap, reg, &val); \
89 	dev_dbg(dev, "%20s= 0x%08x\n", #reg, val); \
90 } while (0)
91 
92 struct tsc_param {
93 	/* Each step is 1024 us.  Valid 1-256 */
94 	u32 scanning_period;
95 
96 	/*  Each step is 512 us.  Valid 0-255 */
97 	u32 debounce_timeout;
98 
99 	/*
100 	 * The settling duration (in ms) is the amount of time the tsc
101 	 * waits to allow the voltage to settle after turning on the
102 	 * drivers in detection mode. Valid values: 0-11
103 	 *   0 =  0.008 ms
104 	 *   1 =  0.01 ms
105 	 *   2 =  0.02 ms
106 	 *   3 =  0.04 ms
107 	 *   4 =  0.08 ms
108 	 *   5 =  0.16 ms
109 	 *   6 =  0.32 ms
110 	 *   7 =  0.64 ms
111 	 *   8 =  1.28 ms
112 	 *   9 =  2.56 ms
113 	 *   10 = 5.12 ms
114 	 *   11 = 10.24 ms
115 	 */
116 	u32 settling_timeout;
117 
118 	/* touch timeout in sample counts */
119 	u32 touch_timeout;
120 
121 	/*
122 	 * Number of data samples which are averaged before a final data point
123 	 * is placed into the FIFO
124 	 */
125 	u32 average_data;
126 
127 	/* FIFO threshold */
128 	u32 fifo_threshold;
129 
130 	/* Optional standard touchscreen properties. */
131 	u32 max_x;
132 	u32 max_y;
133 	u32 fuzz_x;
134 	u32 fuzz_y;
135 	bool invert_x;
136 	bool invert_y;
137 };
138 
139 struct iproc_ts_priv {
140 	struct platform_device *pdev;
141 	struct input_dev *idev;
142 
143 	struct regmap *regmap;
144 	struct clk *tsc_clk;
145 
146 	int  pen_status;
147 	struct tsc_param cfg_params;
148 };
149 
150 /*
151  * Set default values the same as hardware reset values
152  * except for fifo_threshold with is set to 1.
153  */
154 static const struct tsc_param iproc_default_config = {
155 	.scanning_period  = 0x5,  /* 1 to 256 */
156 	.debounce_timeout = 0x28, /* 0 to 255 */
157 	.settling_timeout = 0x7,  /* 0 to 11 */
158 	.touch_timeout    = 0xa,  /* 0 to 255 */
159 	.average_data     = 5,    /* entry 5 = 32 pts */
160 	.fifo_threshold   = 1,    /* 0 to 31 */
161 	.max_x            = X_MAX,
162 	.max_y            = Y_MAX,
163 };
164 
ts_reg_dump(struct iproc_ts_priv * priv)165 static void ts_reg_dump(struct iproc_ts_priv *priv)
166 {
167 	struct device *dev = &priv->pdev->dev;
168 
169 	dbg_reg(dev, priv, REGCTL1);
170 	dbg_reg(dev, priv, REGCTL2);
171 	dbg_reg(dev, priv, INTERRUPT_THRES);
172 	dbg_reg(dev, priv, INTERRUPT_MASK);
173 	dbg_reg(dev, priv, INTERRUPT_STATUS);
174 	dbg_reg(dev, priv, CONTROLLER_STATUS);
175 	dbg_reg(dev, priv, FIFO_DATA);
176 	dbg_reg(dev, priv, ANALOG_CONTROL);
177 	dbg_reg(dev, priv, AUX_DATA);
178 	dbg_reg(dev, priv, DEBOUNCE_CNTR_STAT);
179 	dbg_reg(dev, priv, SCAN_CNTR_STAT);
180 	dbg_reg(dev, priv, REM_CNTR_STAT);
181 	dbg_reg(dev, priv, SETTLING_TIMER_STAT);
182 	dbg_reg(dev, priv, SPARE_REG);
183 	dbg_reg(dev, priv, SOFT_BYPASS_CONTROL);
184 	dbg_reg(dev, priv, SOFT_BYPASS_DATA);
185 }
186 
iproc_touchscreen_interrupt(int irq,void * data)187 static irqreturn_t iproc_touchscreen_interrupt(int irq, void *data)
188 {
189 	struct platform_device *pdev = data;
190 	struct iproc_ts_priv *priv = platform_get_drvdata(pdev);
191 	u32 intr_status;
192 	u32 raw_coordinate;
193 	u16 x;
194 	u16 y;
195 	int i;
196 	bool needs_sync = false;
197 
198 	regmap_read(priv->regmap, INTERRUPT_STATUS, &intr_status);
199 	intr_status &= TS_PEN_INTR_MASK | TS_FIFO_INTR_MASK;
200 	if (intr_status == 0)
201 		return IRQ_NONE;
202 
203 	/* Clear all interrupt status bits, write-1-clear */
204 	regmap_write(priv->regmap, INTERRUPT_STATUS, intr_status);
205 	/* Pen up/down */
206 	if (intr_status & TS_PEN_INTR_MASK) {
207 		regmap_read(priv->regmap, CONTROLLER_STATUS, &priv->pen_status);
208 		if (priv->pen_status & TS_PEN_DOWN)
209 			priv->pen_status = PEN_DOWN_STATUS;
210 		else
211 			priv->pen_status = PEN_UP_STATUS;
212 
213 		input_report_key(priv->idev, BTN_TOUCH,	priv->pen_status);
214 		needs_sync = true;
215 
216 		dev_dbg(&priv->pdev->dev,
217 			"pen up-down (%d)\n", priv->pen_status);
218 	}
219 
220 	/* coordinates in FIFO exceed the theshold */
221 	if (intr_status & TS_FIFO_INTR_MASK) {
222 		for (i = 0; i < priv->cfg_params.fifo_threshold; i++) {
223 			regmap_read(priv->regmap, FIFO_DATA, &raw_coordinate);
224 			if (raw_coordinate == INVALID_COORD)
225 				continue;
226 
227 			/*
228 			 * The x and y coordinate are 16 bits each
229 			 * with the x in the lower 16 bits and y in the
230 			 * upper 16 bits.
231 			 */
232 			x = (raw_coordinate >> X_COORD_SHIFT) &
233 				FIFO_DATA_X_Y_MASK;
234 			y = (raw_coordinate >> Y_COORD_SHIFT) &
235 				FIFO_DATA_X_Y_MASK;
236 
237 			/* We only want to retain the 12 msb of the 16 */
238 			x = (x >> 4) & 0x0FFF;
239 			y = (y >> 4) & 0x0FFF;
240 
241 			/* Adjust x y according to LCD tsc mount angle. */
242 			if (priv->cfg_params.invert_x)
243 				x = priv->cfg_params.max_x - x;
244 
245 			if (priv->cfg_params.invert_y)
246 				y = priv->cfg_params.max_y - y;
247 
248 			input_report_abs(priv->idev, ABS_X, x);
249 			input_report_abs(priv->idev, ABS_Y, y);
250 			needs_sync = true;
251 
252 			dev_dbg(&priv->pdev->dev, "xy (0x%x 0x%x)\n", x, y);
253 		}
254 	}
255 
256 	if (needs_sync)
257 		input_sync(priv->idev);
258 
259 	return IRQ_HANDLED;
260 }
261 
iproc_ts_start(struct input_dev * idev)262 static int iproc_ts_start(struct input_dev *idev)
263 {
264 	u32 val;
265 	u32 mask;
266 	int error;
267 	struct iproc_ts_priv *priv = input_get_drvdata(idev);
268 
269 	/* Enable clock */
270 	error = clk_prepare_enable(priv->tsc_clk);
271 	if (error) {
272 		dev_err(&priv->pdev->dev, "%s clk_prepare_enable failed %d\n",
273 			__func__, error);
274 		return error;
275 	}
276 
277 	/*
278 	 * Interrupt is generated when:
279 	 *  FIFO reaches the int_th value, and pen event(up/down)
280 	 */
281 	val = TS_PEN_INTR_MASK | TS_FIFO_INTR_MASK;
282 	regmap_update_bits(priv->regmap, INTERRUPT_MASK, val, val);
283 
284 	val = priv->cfg_params.fifo_threshold;
285 	regmap_write(priv->regmap, INTERRUPT_THRES, val);
286 
287 	/* Initialize control reg1 */
288 	val = 0;
289 	val |= priv->cfg_params.scanning_period << SCANNING_PERIOD_SHIFT;
290 	val |= priv->cfg_params.debounce_timeout << DEBOUNCE_TIMEOUT_SHIFT;
291 	val |= priv->cfg_params.settling_timeout << SETTLING_TIMEOUT_SHIFT;
292 	val |= priv->cfg_params.touch_timeout << TOUCH_TIMEOUT_SHIFT;
293 	regmap_write(priv->regmap, REGCTL1, val);
294 
295 	/* Try to clear all interrupt status */
296 	val = TS_FIFO_INTR_MASK | TS_PEN_INTR_MASK;
297 	regmap_update_bits(priv->regmap, INTERRUPT_STATUS, val, val);
298 
299 	/* Initialize control reg2 */
300 	val = TS_CONTROLLER_EN_BIT | TS_WIRE_MODE_BIT;
301 	val |= priv->cfg_params.average_data << TS_CONTROLLER_AVGDATA_SHIFT;
302 
303 	mask = (TS_CONTROLLER_AVGDATA_MASK);
304 	mask |= (TS_CONTROLLER_PWR_LDO |	/* PWR up LDO */
305 		   TS_CONTROLLER_PWR_ADC |	/* PWR up ADC */
306 		   TS_CONTROLLER_PWR_BGP |	/* PWR up BGP */
307 		   TS_CONTROLLER_PWR_TS);	/* PWR up TS */
308 	mask |= val;
309 	regmap_update_bits(priv->regmap, REGCTL2, mask, val);
310 
311 	ts_reg_dump(priv);
312 
313 	return 0;
314 }
315 
iproc_ts_stop(struct input_dev * dev)316 static void iproc_ts_stop(struct input_dev *dev)
317 {
318 	u32 val;
319 	struct iproc_ts_priv *priv = input_get_drvdata(dev);
320 
321 	/*
322 	 * Disable FIFO int_th and pen event(up/down)Interrupts only
323 	 * as the interrupt mask register is shared between ADC, TS and
324 	 * flextimer.
325 	 */
326 	val = TS_PEN_INTR_MASK | TS_FIFO_INTR_MASK;
327 	regmap_update_bits(priv->regmap, INTERRUPT_MASK, val, 0);
328 
329 	/* Only power down touch screen controller */
330 	val = TS_CONTROLLER_PWR_TS;
331 	regmap_update_bits(priv->regmap, REGCTL2, val, val);
332 
333 	clk_disable(priv->tsc_clk);
334 }
335 
iproc_get_tsc_config(struct device * dev,struct iproc_ts_priv * priv)336 static int iproc_get_tsc_config(struct device *dev, struct iproc_ts_priv *priv)
337 {
338 	struct device_node *np = dev->of_node;
339 	u32 val;
340 
341 	priv->cfg_params = iproc_default_config;
342 
343 	if (!np)
344 		return 0;
345 
346 	if (of_property_read_u32(np, "scanning_period", &val) >= 0) {
347 		if (val < 1 || val > 256) {
348 			dev_err(dev, "scanning_period (%u) must be [1-256]\n",
349 				val);
350 			return -EINVAL;
351 		}
352 		priv->cfg_params.scanning_period = val;
353 	}
354 
355 	if (of_property_read_u32(np, "debounce_timeout", &val) >= 0) {
356 		if (val > 255) {
357 			dev_err(dev, "debounce_timeout (%u) must be [0-255]\n",
358 				val);
359 			return -EINVAL;
360 		}
361 		priv->cfg_params.debounce_timeout = val;
362 	}
363 
364 	if (of_property_read_u32(np, "settling_timeout", &val) >= 0) {
365 		if (val > 11) {
366 			dev_err(dev, "settling_timeout (%u) must be [0-11]\n",
367 				val);
368 			return -EINVAL;
369 		}
370 		priv->cfg_params.settling_timeout = val;
371 	}
372 
373 	if (of_property_read_u32(np, "touch_timeout", &val) >= 0) {
374 		if (val > 255) {
375 			dev_err(dev, "touch_timeout (%u) must be [0-255]\n",
376 				val);
377 			return -EINVAL;
378 		}
379 		priv->cfg_params.touch_timeout = val;
380 	}
381 
382 	if (of_property_read_u32(np, "average_data", &val) >= 0) {
383 		if (val > 8) {
384 			dev_err(dev, "average_data (%u) must be [0-8]\n", val);
385 			return -EINVAL;
386 		}
387 		priv->cfg_params.average_data = val;
388 	}
389 
390 	if (of_property_read_u32(np, "fifo_threshold", &val) >= 0) {
391 		if (val > 31) {
392 			dev_err(dev, "fifo_threshold (%u)) must be [0-31]\n",
393 				val);
394 			return -EINVAL;
395 		}
396 		priv->cfg_params.fifo_threshold = val;
397 	}
398 
399 	/* Parse optional properties. */
400 	of_property_read_u32(np, "touchscreen-size-x", &priv->cfg_params.max_x);
401 	of_property_read_u32(np, "touchscreen-size-y", &priv->cfg_params.max_y);
402 
403 	of_property_read_u32(np, "touchscreen-fuzz-x",
404 			     &priv->cfg_params.fuzz_x);
405 	of_property_read_u32(np, "touchscreen-fuzz-y",
406 			     &priv->cfg_params.fuzz_y);
407 
408 	priv->cfg_params.invert_x =
409 		of_property_read_bool(np, "touchscreen-inverted-x");
410 	priv->cfg_params.invert_y =
411 		of_property_read_bool(np, "touchscreen-inverted-y");
412 
413 	return 0;
414 }
415 
iproc_ts_probe(struct platform_device * pdev)416 static int iproc_ts_probe(struct platform_device *pdev)
417 {
418 	struct iproc_ts_priv *priv;
419 	struct input_dev *idev;
420 	int irq;
421 	int error;
422 
423 	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
424 	if (!priv)
425 		return -ENOMEM;
426 
427 	/* touchscreen controller memory mapped regs via syscon*/
428 	priv->regmap = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
429 							"ts_syscon");
430 	if (IS_ERR(priv->regmap)) {
431 		error = PTR_ERR(priv->regmap);
432 		dev_err(&pdev->dev, "unable to map I/O memory:%d\n", error);
433 		return error;
434 	}
435 
436 	priv->tsc_clk = devm_clk_get(&pdev->dev, "tsc_clk");
437 	if (IS_ERR(priv->tsc_clk)) {
438 		error = PTR_ERR(priv->tsc_clk);
439 		dev_err(&pdev->dev,
440 			"failed getting clock tsc_clk: %d\n", error);
441 		return error;
442 	}
443 
444 	priv->pdev = pdev;
445 	error = iproc_get_tsc_config(&pdev->dev, priv);
446 	if (error) {
447 		dev_err(&pdev->dev, "get_tsc_config failed: %d\n", error);
448 		return error;
449 	}
450 
451 	idev = devm_input_allocate_device(&pdev->dev);
452 	if (!idev) {
453 		dev_err(&pdev->dev, "failed to allocate input device\n");
454 		return -ENOMEM;
455 	}
456 
457 	priv->idev = idev;
458 	priv->pen_status = PEN_UP_STATUS;
459 
460 	/* Set input device info  */
461 	idev->name = IPROC_TS_NAME;
462 	idev->dev.parent = &pdev->dev;
463 
464 	idev->id.bustype = BUS_HOST;
465 	idev->id.vendor = SERIO_UNKNOWN;
466 	idev->id.product = 0;
467 	idev->id.version = 0;
468 
469 	idev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
470 	__set_bit(BTN_TOUCH, idev->keybit);
471 
472 	input_set_abs_params(idev, ABS_X, X_MIN, priv->cfg_params.max_x,
473 			     priv->cfg_params.fuzz_x, 0);
474 	input_set_abs_params(idev, ABS_Y, Y_MIN, priv->cfg_params.max_y,
475 			     priv->cfg_params.fuzz_y, 0);
476 
477 	idev->open = iproc_ts_start;
478 	idev->close = iproc_ts_stop;
479 
480 	input_set_drvdata(idev, priv);
481 	platform_set_drvdata(pdev, priv);
482 
483 	/* get interrupt */
484 	irq = platform_get_irq(pdev, 0);
485 	if (irq < 0)
486 		return irq;
487 
488 	error = devm_request_irq(&pdev->dev, irq,
489 				 iproc_touchscreen_interrupt,
490 				 IRQF_SHARED, IPROC_TS_NAME, pdev);
491 	if (error)
492 		return error;
493 
494 	error = input_register_device(priv->idev);
495 	if (error) {
496 		dev_err(&pdev->dev,
497 			"failed to register input device: %d\n", error);
498 		return error;
499 	}
500 
501 	return 0;
502 }
503 
504 static const struct of_device_id iproc_ts_of_match[] = {
505 	{.compatible = "brcm,iproc-touchscreen", },
506 	{ },
507 };
508 MODULE_DEVICE_TABLE(of, iproc_ts_of_match);
509 
510 static struct platform_driver iproc_ts_driver = {
511 	.probe = iproc_ts_probe,
512 	.driver = {
513 		.name	= IPROC_TS_NAME,
514 		.of_match_table = iproc_ts_of_match,
515 	},
516 };
517 
518 module_platform_driver(iproc_ts_driver);
519 
520 MODULE_DESCRIPTION("IPROC Touchscreen driver");
521 MODULE_AUTHOR("Broadcom");
522 MODULE_LICENSE("GPL v2");
523