1 /*
2 * Copyright (C) 2015 Broadcom Corporation
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License as
6 * published by the Free Software Foundation version 2.
7 *
8 * This program is distributed "as is" WITHOUT ANY WARRANTY of any
9 * kind, whether express or implied; without even the implied warranty
10 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 */
13 #include <linux/module.h>
14 #include <linux/init.h>
15 #include <linux/input.h>
16 #include <linux/delay.h>
17 #include <linux/interrupt.h>
18 #include <linux/keyboard.h>
19 #include <linux/platform_device.h>
20 #include <linux/slab.h>
21 #include <linux/of.h>
22 #include <asm/irq.h>
23 #include <linux/io.h>
24 #include <linux/clk.h>
25 #include <linux/serio.h>
26 #include <linux/mfd/syscon.h>
27 #include <linux/regmap.h>
28 
29 #define IPROC_TS_NAME "iproc-ts"
30 
31 #define PEN_DOWN_STATUS     1
32 #define PEN_UP_STATUS       0
33 
34 #define X_MIN               0
35 #define Y_MIN               0
36 #define X_MAX               0xFFF
37 #define Y_MAX               0xFFF
38 
39 /* Value given by controller for invalid coordinate. */
40 #define INVALID_COORD       0xFFFFFFFF
41 
42 /* Register offsets */
43 #define REGCTL1             0x00
44 #define REGCTL2             0x04
45 #define INTERRUPT_THRES     0x08
46 #define INTERRUPT_MASK      0x0c
47 
48 #define INTERRUPT_STATUS    0x10
49 #define CONTROLLER_STATUS   0x14
50 #define FIFO_DATA           0x18
51 #define FIFO_DATA_X_Y_MASK  0xFFFF
52 #define ANALOG_CONTROL      0x1c
53 
54 #define AUX_DATA            0x20
55 #define DEBOUNCE_CNTR_STAT  0x24
56 #define SCAN_CNTR_STAT      0x28
57 #define REM_CNTR_STAT       0x2c
58 
59 #define SETTLING_TIMER_STAT 0x30
60 #define SPARE_REG           0x34
61 #define SOFT_BYPASS_CONTROL 0x38
62 #define SOFT_BYPASS_DATA    0x3c
63 
64 
65 /* Bit values for INTERRUPT_MASK and INTERRUPT_STATUS regs */
66 #define TS_PEN_INTR_MASK        BIT(0)
67 #define TS_FIFO_INTR_MASK       BIT(2)
68 
69 /* Bit values for CONTROLLER_STATUS reg1 */
70 #define TS_PEN_DOWN             BIT(0)
71 
72 /* Shift values for control reg1 */
73 #define SCANNING_PERIOD_SHIFT   24
74 #define DEBOUNCE_TIMEOUT_SHIFT  16
75 #define SETTLING_TIMEOUT_SHIFT  8
76 #define TOUCH_TIMEOUT_SHIFT     0
77 
78 /* Shift values for coordinates from fifo */
79 #define X_COORD_SHIFT  0
80 #define Y_COORD_SHIFT  16
81 
82 /* Bit values for REGCTL2 */
83 #define TS_CONTROLLER_EN_BIT    BIT(16)
84 #define TS_CONTROLLER_AVGDATA_SHIFT 8
85 #define TS_CONTROLLER_AVGDATA_MASK (0x7 << TS_CONTROLLER_AVGDATA_SHIFT)
86 #define TS_CONTROLLER_PWR_LDO   BIT(5)
87 #define TS_CONTROLLER_PWR_ADC   BIT(4)
88 #define TS_CONTROLLER_PWR_BGP   BIT(3)
89 #define TS_CONTROLLER_PWR_TS    BIT(2)
90 #define TS_WIRE_MODE_BIT        BIT(1)
91 
92 #define dbg_reg(dev, priv, reg) \
93 do { \
94 	u32 val; \
95 	regmap_read(priv->regmap, reg, &val); \
96 	dev_dbg(dev, "%20s= 0x%08x\n", #reg, val); \
97 } while (0)
98 
99 struct tsc_param {
100 	/* Each step is 1024 us.  Valid 1-256 */
101 	u32 scanning_period;
102 
103 	/*  Each step is 512 us.  Valid 0-255 */
104 	u32 debounce_timeout;
105 
106 	/*
107 	 * The settling duration (in ms) is the amount of time the tsc
108 	 * waits to allow the voltage to settle after turning on the
109 	 * drivers in detection mode. Valid values: 0-11
110 	 *   0 =  0.008 ms
111 	 *   1 =  0.01 ms
112 	 *   2 =  0.02 ms
113 	 *   3 =  0.04 ms
114 	 *   4 =  0.08 ms
115 	 *   5 =  0.16 ms
116 	 *   6 =  0.32 ms
117 	 *   7 =  0.64 ms
118 	 *   8 =  1.28 ms
119 	 *   9 =  2.56 ms
120 	 *   10 = 5.12 ms
121 	 *   11 = 10.24 ms
122 	 */
123 	u32 settling_timeout;
124 
125 	/* touch timeout in sample counts */
126 	u32 touch_timeout;
127 
128 	/*
129 	 * Number of data samples which are averaged before a final data point
130 	 * is placed into the FIFO
131 	 */
132 	u32 average_data;
133 
134 	/* FIFO threshold */
135 	u32 fifo_threshold;
136 
137 	/* Optional standard touchscreen properties. */
138 	u32 max_x;
139 	u32 max_y;
140 	u32 fuzz_x;
141 	u32 fuzz_y;
142 	bool invert_x;
143 	bool invert_y;
144 };
145 
146 struct iproc_ts_priv {
147 	struct platform_device *pdev;
148 	struct input_dev *idev;
149 
150 	struct regmap *regmap;
151 	struct clk *tsc_clk;
152 
153 	int  pen_status;
154 	struct tsc_param cfg_params;
155 };
156 
157 /*
158  * Set default values the same as hardware reset values
159  * except for fifo_threshold with is set to 1.
160  */
161 static const struct tsc_param iproc_default_config = {
162 	.scanning_period  = 0x5,  /* 1 to 256 */
163 	.debounce_timeout = 0x28, /* 0 to 255 */
164 	.settling_timeout = 0x7,  /* 0 to 11 */
165 	.touch_timeout    = 0xa,  /* 0 to 255 */
166 	.average_data     = 5,    /* entry 5 = 32 pts */
167 	.fifo_threshold   = 1,    /* 0 to 31 */
168 	.max_x            = X_MAX,
169 	.max_y            = Y_MAX,
170 };
171 
172 static void ts_reg_dump(struct iproc_ts_priv *priv)
173 {
174 	struct device *dev = &priv->pdev->dev;
175 
176 	dbg_reg(dev, priv, REGCTL1);
177 	dbg_reg(dev, priv, REGCTL2);
178 	dbg_reg(dev, priv, INTERRUPT_THRES);
179 	dbg_reg(dev, priv, INTERRUPT_MASK);
180 	dbg_reg(dev, priv, INTERRUPT_STATUS);
181 	dbg_reg(dev, priv, CONTROLLER_STATUS);
182 	dbg_reg(dev, priv, FIFO_DATA);
183 	dbg_reg(dev, priv, ANALOG_CONTROL);
184 	dbg_reg(dev, priv, AUX_DATA);
185 	dbg_reg(dev, priv, DEBOUNCE_CNTR_STAT);
186 	dbg_reg(dev, priv, SCAN_CNTR_STAT);
187 	dbg_reg(dev, priv, REM_CNTR_STAT);
188 	dbg_reg(dev, priv, SETTLING_TIMER_STAT);
189 	dbg_reg(dev, priv, SPARE_REG);
190 	dbg_reg(dev, priv, SOFT_BYPASS_CONTROL);
191 	dbg_reg(dev, priv, SOFT_BYPASS_DATA);
192 }
193 
194 static irqreturn_t iproc_touchscreen_interrupt(int irq, void *data)
195 {
196 	struct platform_device *pdev = data;
197 	struct iproc_ts_priv *priv = platform_get_drvdata(pdev);
198 	u32 intr_status;
199 	u32 raw_coordinate;
200 	u16 x;
201 	u16 y;
202 	int i;
203 	bool needs_sync = false;
204 
205 	regmap_read(priv->regmap, INTERRUPT_STATUS, &intr_status);
206 	intr_status &= TS_PEN_INTR_MASK | TS_FIFO_INTR_MASK;
207 	if (intr_status == 0)
208 		return IRQ_NONE;
209 
210 	/* Clear all interrupt status bits, write-1-clear */
211 	regmap_write(priv->regmap, INTERRUPT_STATUS, intr_status);
212 	/* Pen up/down */
213 	if (intr_status & TS_PEN_INTR_MASK) {
214 		regmap_read(priv->regmap, CONTROLLER_STATUS, &priv->pen_status);
215 		if (priv->pen_status & TS_PEN_DOWN)
216 			priv->pen_status = PEN_DOWN_STATUS;
217 		else
218 			priv->pen_status = PEN_UP_STATUS;
219 
220 		input_report_key(priv->idev, BTN_TOUCH,	priv->pen_status);
221 		needs_sync = true;
222 
223 		dev_dbg(&priv->pdev->dev,
224 			"pen up-down (%d)\n", priv->pen_status);
225 	}
226 
227 	/* coordinates in FIFO exceed the theshold */
228 	if (intr_status & TS_FIFO_INTR_MASK) {
229 		for (i = 0; i < priv->cfg_params.fifo_threshold; i++) {
230 			regmap_read(priv->regmap, FIFO_DATA, &raw_coordinate);
231 			if (raw_coordinate == INVALID_COORD)
232 				continue;
233 
234 			/*
235 			 * The x and y coordinate are 16 bits each
236 			 * with the x in the lower 16 bits and y in the
237 			 * upper 16 bits.
238 			 */
239 			x = (raw_coordinate >> X_COORD_SHIFT) &
240 				FIFO_DATA_X_Y_MASK;
241 			y = (raw_coordinate >> Y_COORD_SHIFT) &
242 				FIFO_DATA_X_Y_MASK;
243 
244 			/* We only want to retain the 12 msb of the 16 */
245 			x = (x >> 4) & 0x0FFF;
246 			y = (y >> 4) & 0x0FFF;
247 
248 			/* Adjust x y according to LCD tsc mount angle. */
249 			if (priv->cfg_params.invert_x)
250 				x = priv->cfg_params.max_x - x;
251 
252 			if (priv->cfg_params.invert_y)
253 				y = priv->cfg_params.max_y - y;
254 
255 			input_report_abs(priv->idev, ABS_X, x);
256 			input_report_abs(priv->idev, ABS_Y, y);
257 			needs_sync = true;
258 
259 			dev_dbg(&priv->pdev->dev, "xy (0x%x 0x%x)\n", x, y);
260 		}
261 	}
262 
263 	if (needs_sync)
264 		input_sync(priv->idev);
265 
266 	return IRQ_HANDLED;
267 }
268 
269 static int iproc_ts_start(struct input_dev *idev)
270 {
271 	u32 val;
272 	u32 mask;
273 	int error;
274 	struct iproc_ts_priv *priv = input_get_drvdata(idev);
275 
276 	/* Enable clock */
277 	error = clk_prepare_enable(priv->tsc_clk);
278 	if (error) {
279 		dev_err(&priv->pdev->dev, "%s clk_prepare_enable failed %d\n",
280 			__func__, error);
281 		return error;
282 	}
283 
284 	/*
285 	 * Interrupt is generated when:
286 	 *  FIFO reaches the int_th value, and pen event(up/down)
287 	 */
288 	val = TS_PEN_INTR_MASK | TS_FIFO_INTR_MASK;
289 	regmap_update_bits(priv->regmap, INTERRUPT_MASK, val, val);
290 
291 	val = priv->cfg_params.fifo_threshold;
292 	regmap_write(priv->regmap, INTERRUPT_THRES, val);
293 
294 	/* Initialize control reg1 */
295 	val = 0;
296 	val |= priv->cfg_params.scanning_period << SCANNING_PERIOD_SHIFT;
297 	val |= priv->cfg_params.debounce_timeout << DEBOUNCE_TIMEOUT_SHIFT;
298 	val |= priv->cfg_params.settling_timeout << SETTLING_TIMEOUT_SHIFT;
299 	val |= priv->cfg_params.touch_timeout << TOUCH_TIMEOUT_SHIFT;
300 	regmap_write(priv->regmap, REGCTL1, val);
301 
302 	/* Try to clear all interrupt status */
303 	val = TS_FIFO_INTR_MASK | TS_PEN_INTR_MASK;
304 	regmap_update_bits(priv->regmap, INTERRUPT_STATUS, val, val);
305 
306 	/* Initialize control reg2 */
307 	val = TS_CONTROLLER_EN_BIT | TS_WIRE_MODE_BIT;
308 	val |= priv->cfg_params.average_data << TS_CONTROLLER_AVGDATA_SHIFT;
309 
310 	mask = (TS_CONTROLLER_AVGDATA_MASK);
311 	mask |= (TS_CONTROLLER_PWR_LDO |	/* PWR up LDO */
312 		   TS_CONTROLLER_PWR_ADC |	/* PWR up ADC */
313 		   TS_CONTROLLER_PWR_BGP |	/* PWR up BGP */
314 		   TS_CONTROLLER_PWR_TS);	/* PWR up TS */
315 	mask |= val;
316 	regmap_update_bits(priv->regmap, REGCTL2, mask, val);
317 
318 	ts_reg_dump(priv);
319 
320 	return 0;
321 }
322 
323 static void iproc_ts_stop(struct input_dev *dev)
324 {
325 	u32 val;
326 	struct iproc_ts_priv *priv = input_get_drvdata(dev);
327 
328 	/*
329 	 * Disable FIFO int_th and pen event(up/down)Interrupts only
330 	 * as the interrupt mask register is shared between ADC, TS and
331 	 * flextimer.
332 	 */
333 	val = TS_PEN_INTR_MASK | TS_FIFO_INTR_MASK;
334 	regmap_update_bits(priv->regmap, INTERRUPT_MASK, val, 0);
335 
336 	/* Only power down touch screen controller */
337 	val = TS_CONTROLLER_PWR_TS;
338 	regmap_update_bits(priv->regmap, REGCTL2, val, val);
339 
340 	clk_disable(priv->tsc_clk);
341 }
342 
343 static int iproc_get_tsc_config(struct device *dev, struct iproc_ts_priv *priv)
344 {
345 	struct device_node *np = dev->of_node;
346 	u32 val;
347 
348 	priv->cfg_params = iproc_default_config;
349 
350 	if (!np)
351 		return 0;
352 
353 	if (of_property_read_u32(np, "scanning_period", &val) >= 0) {
354 		if (val < 1 || val > 256) {
355 			dev_err(dev, "scanning_period (%u) must be [1-256]\n",
356 				val);
357 			return -EINVAL;
358 		}
359 		priv->cfg_params.scanning_period = val;
360 	}
361 
362 	if (of_property_read_u32(np, "debounce_timeout", &val) >= 0) {
363 		if (val > 255) {
364 			dev_err(dev, "debounce_timeout (%u) must be [0-255]\n",
365 				val);
366 			return -EINVAL;
367 		}
368 		priv->cfg_params.debounce_timeout = val;
369 	}
370 
371 	if (of_property_read_u32(np, "settling_timeout", &val) >= 0) {
372 		if (val > 11) {
373 			dev_err(dev, "settling_timeout (%u) must be [0-11]\n",
374 				val);
375 			return -EINVAL;
376 		}
377 		priv->cfg_params.settling_timeout = val;
378 	}
379 
380 	if (of_property_read_u32(np, "touch_timeout", &val) >= 0) {
381 		if (val > 255) {
382 			dev_err(dev, "touch_timeout (%u) must be [0-255]\n",
383 				val);
384 			return -EINVAL;
385 		}
386 		priv->cfg_params.touch_timeout = val;
387 	}
388 
389 	if (of_property_read_u32(np, "average_data", &val) >= 0) {
390 		if (val > 8) {
391 			dev_err(dev, "average_data (%u) must be [0-8]\n", val);
392 			return -EINVAL;
393 		}
394 		priv->cfg_params.average_data = val;
395 	}
396 
397 	if (of_property_read_u32(np, "fifo_threshold", &val) >= 0) {
398 		if (val > 31) {
399 			dev_err(dev, "fifo_threshold (%u)) must be [0-31]\n",
400 				val);
401 			return -EINVAL;
402 		}
403 		priv->cfg_params.fifo_threshold = val;
404 	}
405 
406 	/* Parse optional properties. */
407 	of_property_read_u32(np, "touchscreen-size-x", &priv->cfg_params.max_x);
408 	of_property_read_u32(np, "touchscreen-size-y", &priv->cfg_params.max_y);
409 
410 	of_property_read_u32(np, "touchscreen-fuzz-x",
411 			     &priv->cfg_params.fuzz_x);
412 	of_property_read_u32(np, "touchscreen-fuzz-y",
413 			     &priv->cfg_params.fuzz_y);
414 
415 	priv->cfg_params.invert_x =
416 		of_property_read_bool(np, "touchscreen-inverted-x");
417 	priv->cfg_params.invert_y =
418 		of_property_read_bool(np, "touchscreen-inverted-y");
419 
420 	return 0;
421 }
422 
423 static int iproc_ts_probe(struct platform_device *pdev)
424 {
425 	struct iproc_ts_priv *priv;
426 	struct input_dev *idev;
427 	int irq;
428 	int error;
429 
430 	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
431 	if (!priv)
432 		return -ENOMEM;
433 
434 	/* touchscreen controller memory mapped regs via syscon*/
435 	priv->regmap = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
436 							"ts_syscon");
437 	if (IS_ERR(priv->regmap)) {
438 		error = PTR_ERR(priv->regmap);
439 		dev_err(&pdev->dev, "unable to map I/O memory:%d\n", error);
440 		return error;
441 	}
442 
443 	priv->tsc_clk = devm_clk_get(&pdev->dev, "tsc_clk");
444 	if (IS_ERR(priv->tsc_clk)) {
445 		error = PTR_ERR(priv->tsc_clk);
446 		dev_err(&pdev->dev,
447 			"failed getting clock tsc_clk: %d\n", error);
448 		return error;
449 	}
450 
451 	priv->pdev = pdev;
452 	error = iproc_get_tsc_config(&pdev->dev, priv);
453 	if (error) {
454 		dev_err(&pdev->dev, "get_tsc_config failed: %d\n", error);
455 		return error;
456 	}
457 
458 	idev = devm_input_allocate_device(&pdev->dev);
459 	if (!idev) {
460 		dev_err(&pdev->dev, "failed to allocate input device\n");
461 		return -ENOMEM;
462 	}
463 
464 	priv->idev = idev;
465 	priv->pen_status = PEN_UP_STATUS;
466 
467 	/* Set input device info  */
468 	idev->name = IPROC_TS_NAME;
469 	idev->dev.parent = &pdev->dev;
470 
471 	idev->id.bustype = BUS_HOST;
472 	idev->id.vendor = SERIO_UNKNOWN;
473 	idev->id.product = 0;
474 	idev->id.version = 0;
475 
476 	idev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
477 	__set_bit(BTN_TOUCH, idev->keybit);
478 
479 	input_set_abs_params(idev, ABS_X, X_MIN, priv->cfg_params.max_x,
480 			     priv->cfg_params.fuzz_x, 0);
481 	input_set_abs_params(idev, ABS_Y, Y_MIN, priv->cfg_params.max_y,
482 			     priv->cfg_params.fuzz_y, 0);
483 
484 	idev->open = iproc_ts_start;
485 	idev->close = iproc_ts_stop;
486 
487 	input_set_drvdata(idev, priv);
488 	platform_set_drvdata(pdev, priv);
489 
490 	/* get interrupt */
491 	irq = platform_get_irq(pdev, 0);
492 	if (irq < 0)
493 		return irq;
494 
495 	error = devm_request_irq(&pdev->dev, irq,
496 				 iproc_touchscreen_interrupt,
497 				 IRQF_SHARED, IPROC_TS_NAME, pdev);
498 	if (error)
499 		return error;
500 
501 	error = input_register_device(priv->idev);
502 	if (error) {
503 		dev_err(&pdev->dev,
504 			"failed to register input device: %d\n", error);
505 		return error;
506 	}
507 
508 	return 0;
509 }
510 
511 static const struct of_device_id iproc_ts_of_match[] = {
512 	{.compatible = "brcm,iproc-touchscreen", },
513 	{ },
514 };
515 MODULE_DEVICE_TABLE(of, iproc_ts_of_match);
516 
517 static struct platform_driver iproc_ts_driver = {
518 	.probe = iproc_ts_probe,
519 	.driver = {
520 		.name	= IPROC_TS_NAME,
521 		.of_match_table = of_match_ptr(iproc_ts_of_match),
522 	},
523 };
524 
525 module_platform_driver(iproc_ts_driver);
526 
527 MODULE_DESCRIPTION("IPROC Touchscreen driver");
528 MODULE_AUTHOR("Broadcom");
529 MODULE_LICENSE("GPL v2");
530