1 /*
2  * TSI driver for Dialog DA9052
3  *
4  * Copyright(c) 2012 Dialog Semiconductor Ltd.
5  *
6  * Author: David Dajun Chen <dchen@diasemi.com>
7  *
8  *  This program is free software; you can redistribute  it and/or modify it
9  *  under  the terms of  the GNU General  Public License as published by the
10  *  Free Software Foundation;  either version 2 of the  License, or (at your
11  *  option) any later version.
12  *
13  */
14 #include <linux/module.h>
15 #include <linux/input.h>
16 #include <linux/delay.h>
17 #include <linux/platform_device.h>
18 #include <linux/interrupt.h>
19 
20 #include <linux/mfd/da9052/reg.h>
21 #include <linux/mfd/da9052/da9052.h>
22 
23 #define TSI_PEN_DOWN_STATUS 0x40
24 
25 struct da9052_tsi {
26 	struct da9052 *da9052;
27 	struct input_dev *dev;
28 	struct delayed_work ts_pen_work;
29 	struct mutex mutex;
30 	unsigned int irq_pendwn;
31 	unsigned int irq_datardy;
32 	bool stopped;
33 	bool adc_on;
34 };
35 
36 static void da9052_ts_adc_toggle(struct da9052_tsi *tsi, bool on)
37 {
38 	da9052_reg_update(tsi->da9052, DA9052_TSI_CONT_A_REG, 1 << 0, on);
39 	tsi->adc_on = on;
40 }
41 
42 static irqreturn_t da9052_ts_pendwn_irq(int irq, void *data)
43 {
44 	struct da9052_tsi *tsi = data;
45 
46 	if (!tsi->stopped) {
47 		/* Mask PEN_DOWN event and unmask TSI_READY event */
48 		disable_irq_nosync(tsi->irq_pendwn);
49 		enable_irq(tsi->irq_datardy);
50 
51 		da9052_ts_adc_toggle(tsi, true);
52 
53 		schedule_delayed_work(&tsi->ts_pen_work, HZ / 50);
54 	}
55 
56 	return IRQ_HANDLED;
57 }
58 
59 static void da9052_ts_read(struct da9052_tsi *tsi)
60 {
61 	struct input_dev *input = tsi->dev;
62 	int ret;
63 	u16 x, y, z;
64 	u8 v;
65 
66 	ret = da9052_reg_read(tsi->da9052, DA9052_TSI_X_MSB_REG);
67 	if (ret < 0)
68 		return;
69 
70 	x = (u16) ret;
71 
72 	ret = da9052_reg_read(tsi->da9052, DA9052_TSI_Y_MSB_REG);
73 	if (ret < 0)
74 		return;
75 
76 	y = (u16) ret;
77 
78 	ret = da9052_reg_read(tsi->da9052, DA9052_TSI_Z_MSB_REG);
79 	if (ret < 0)
80 		return;
81 
82 	z = (u16) ret;
83 
84 	ret = da9052_reg_read(tsi->da9052, DA9052_TSI_LSB_REG);
85 	if (ret < 0)
86 		return;
87 
88 	v = (u8) ret;
89 
90 	x = ((x << 2) & 0x3fc) | (v & 0x3);
91 	y = ((y << 2) & 0x3fc) | ((v & 0xc) >> 2);
92 	z = ((z << 2) & 0x3fc) | ((v & 0x30) >> 4);
93 
94 	input_report_key(input, BTN_TOUCH, 1);
95 	input_report_abs(input, ABS_X, x);
96 	input_report_abs(input, ABS_Y, y);
97 	input_report_abs(input, ABS_PRESSURE, z);
98 	input_sync(input);
99 }
100 
101 static irqreturn_t da9052_ts_datardy_irq(int irq, void *data)
102 {
103 	struct da9052_tsi *tsi = data;
104 
105 	da9052_ts_read(tsi);
106 
107 	return IRQ_HANDLED;
108 }
109 
110 static void da9052_ts_pen_work(struct work_struct *work)
111 {
112 	struct da9052_tsi *tsi = container_of(work, struct da9052_tsi,
113 					      ts_pen_work.work);
114 	if (!tsi->stopped) {
115 		int ret = da9052_reg_read(tsi->da9052, DA9052_TSI_LSB_REG);
116 		if (ret < 0 || (ret & TSI_PEN_DOWN_STATUS)) {
117 			/* Pen is still DOWN (or read error) */
118 			schedule_delayed_work(&tsi->ts_pen_work, HZ / 50);
119 		} else {
120 			struct input_dev *input = tsi->dev;
121 
122 			/* Pen UP */
123 			da9052_ts_adc_toggle(tsi, false);
124 
125 			/* Report Pen UP */
126 			input_report_key(input, BTN_TOUCH, 0);
127 			input_report_abs(input, ABS_PRESSURE, 0);
128 			input_sync(input);
129 
130 			/*
131 			 * FIXME: Fixes the unhandled irq issue when quick
132 			 * pen down and pen up events occurs
133 			 */
134 			ret = da9052_reg_update(tsi->da9052,
135 						DA9052_EVENT_B_REG, 0xC0, 0xC0);
136 			if (ret < 0)
137 				return;
138 
139 			/* Mask TSI_READY event and unmask PEN_DOWN event */
140 			disable_irq(tsi->irq_datardy);
141 			enable_irq(tsi->irq_pendwn);
142 		}
143 	}
144 }
145 
146 static int __devinit da9052_ts_configure_gpio(struct da9052 *da9052)
147 {
148 	int error;
149 
150 	error = da9052_reg_update(da9052, DA9052_GPIO_2_3_REG, 0x30, 0);
151 	if (error < 0)
152 		return error;
153 
154 	error = da9052_reg_update(da9052, DA9052_GPIO_4_5_REG, 0x33, 0);
155 	if (error < 0)
156 		return error;
157 
158 	error = da9052_reg_update(da9052, DA9052_GPIO_6_7_REG, 0x33, 0);
159 	if (error < 0)
160 		return error;
161 
162 	return 0;
163 }
164 
165 static int __devinit da9052_configure_tsi(struct da9052_tsi *tsi)
166 {
167 	int error;
168 
169 	error = da9052_ts_configure_gpio(tsi->da9052);
170 	if (error)
171 		return error;
172 
173 	/* Measure TSI sample every 1ms */
174 	error = da9052_reg_update(tsi->da9052, DA9052_ADC_CONT_REG,
175 				  1 << 6, 1 << 6);
176 	if (error < 0)
177 		return error;
178 
179 	/* TSI_DELAY: 3 slots, TSI_SKIP: 0 slots, TSI_MODE: XYZP */
180 	error = da9052_reg_update(tsi->da9052, DA9052_TSI_CONT_A_REG, 0xFC, 0xC0);
181 	if (error < 0)
182 		return error;
183 
184 	/* Supply TSIRef through LD09 */
185 	error = da9052_reg_write(tsi->da9052, DA9052_LDO9_REG, 0x59);
186 	if (error < 0)
187 		return error;
188 
189 	return 0;
190 }
191 
192 static int da9052_ts_input_open(struct input_dev *input_dev)
193 {
194 	struct da9052_tsi *tsi = input_get_drvdata(input_dev);
195 
196 	tsi->stopped = false;
197 	mb();
198 
199 	/* Unmask PEN_DOWN event */
200 	enable_irq(tsi->irq_pendwn);
201 
202 	/* Enable Pen Detect Circuit */
203 	return da9052_reg_update(tsi->da9052, DA9052_TSI_CONT_A_REG,
204 				 1 << 1, 1 << 1);
205 }
206 
207 static void da9052_ts_input_close(struct input_dev *input_dev)
208 {
209 	struct da9052_tsi *tsi = input_get_drvdata(input_dev);
210 
211 	tsi->stopped = true;
212 	mb();
213 	disable_irq(tsi->irq_pendwn);
214 	cancel_delayed_work_sync(&tsi->ts_pen_work);
215 
216 	if (tsi->adc_on) {
217 		disable_irq(tsi->irq_datardy);
218 		da9052_ts_adc_toggle(tsi, false);
219 
220 		/*
221 		 * If ADC was on that means that pendwn IRQ was disabled
222 		 * twice and we need to enable it to keep enable/disable
223 		 * counter balanced. IRQ is still off though.
224 		 */
225 		enable_irq(tsi->irq_pendwn);
226 	}
227 
228 	/* Disable Pen Detect Circuit */
229 	da9052_reg_update(tsi->da9052, DA9052_TSI_CONT_A_REG, 1 << 1, 0);
230 }
231 
232 static int __devinit da9052_ts_probe(struct platform_device *pdev)
233 {
234 	struct da9052 *da9052;
235 	struct da9052_tsi *tsi;
236 	struct input_dev *input_dev;
237 	int irq_pendwn;
238 	int irq_datardy;
239 	int error;
240 
241 	da9052 = dev_get_drvdata(pdev->dev.parent);
242 	if (!da9052)
243 		return -EINVAL;
244 
245 	irq_pendwn = platform_get_irq_byname(pdev, "PENDWN");
246 	irq_datardy = platform_get_irq_byname(pdev, "TSIRDY");
247 	if (irq_pendwn < 0 || irq_datardy < 0) {
248 		dev_err(da9052->dev, "Unable to determine device interrupts\n");
249 		return -ENXIO;
250 	}
251 
252 	tsi = kzalloc(sizeof(struct da9052_tsi), GFP_KERNEL);
253 	input_dev = input_allocate_device();
254 	if (!tsi || !input_dev) {
255 		error = -ENOMEM;
256 		goto err_free_mem;
257 	}
258 
259 	tsi->da9052 = da9052;
260 	tsi->dev = input_dev;
261 	tsi->irq_pendwn = da9052->irq_base + irq_pendwn;
262 	tsi->irq_datardy = da9052->irq_base + irq_datardy;
263 	tsi->stopped = true;
264 	INIT_DELAYED_WORK(&tsi->ts_pen_work, da9052_ts_pen_work);
265 
266 	input_dev->id.version = 0x0101;
267 	input_dev->id.vendor = 0x15B6;
268 	input_dev->id.product = 0x9052;
269 	input_dev->name = "Dialog DA9052 TouchScreen Driver";
270 	input_dev->dev.parent = &pdev->dev;
271 	input_dev->open = da9052_ts_input_open;
272 	input_dev->close = da9052_ts_input_close;
273 
274 	__set_bit(EV_ABS, input_dev->evbit);
275 	__set_bit(EV_KEY, input_dev->evbit);
276 	__set_bit(BTN_TOUCH, input_dev->keybit);
277 
278 	input_set_abs_params(input_dev, ABS_X, 0, 1023, 0, 0);
279 	input_set_abs_params(input_dev, ABS_Y, 0, 1023, 0, 0);
280 	input_set_abs_params(input_dev, ABS_PRESSURE, 0, 1023, 0, 0);
281 
282 	input_set_drvdata(input_dev, tsi);
283 
284 	/* Disable Pen Detect Circuit */
285 	da9052_reg_update(tsi->da9052, DA9052_TSI_CONT_A_REG, 1 << 1, 0);
286 
287 	/* Disable ADC */
288 	da9052_ts_adc_toggle(tsi, false);
289 
290 	error = request_threaded_irq(tsi->irq_pendwn,
291 				     NULL, da9052_ts_pendwn_irq,
292 				     IRQF_TRIGGER_LOW | IRQF_ONESHOT,
293 				     "PENDWN", tsi);
294 	if (error) {
295 		dev_err(tsi->da9052->dev,
296 			"Failed to register PENDWN IRQ %d, error = %d\n",
297 			tsi->irq_pendwn, error);
298 		goto err_free_mem;
299 	}
300 
301 	error = request_threaded_irq(tsi->irq_datardy,
302 				     NULL, da9052_ts_datardy_irq,
303 				     IRQF_TRIGGER_LOW | IRQF_ONESHOT,
304 				     "TSIRDY", tsi);
305 	if (error) {
306 		dev_err(tsi->da9052->dev,
307 			"Failed to register TSIRDY IRQ %d, error = %d\n",
308 			tsi->irq_datardy, error);
309 		goto err_free_pendwn_irq;
310 	}
311 
312 	/* Mask PEN_DOWN and TSI_READY events */
313 	disable_irq(tsi->irq_pendwn);
314 	disable_irq(tsi->irq_datardy);
315 
316 	error = da9052_configure_tsi(tsi);
317 	if (error)
318 		goto err_free_datardy_irq;
319 
320 	error = input_register_device(tsi->dev);
321 	if (error)
322 		goto err_free_datardy_irq;
323 
324 	platform_set_drvdata(pdev, tsi);
325 
326 	return 0;
327 
328 err_free_datardy_irq:
329 	free_irq(tsi->irq_datardy, tsi);
330 err_free_pendwn_irq:
331 	free_irq(tsi->irq_pendwn, tsi);
332 err_free_mem:
333 	kfree(tsi);
334 	input_free_device(input_dev);
335 
336 	return error;
337 }
338 
339 static int  __devexit da9052_ts_remove(struct platform_device *pdev)
340 {
341 	struct da9052_tsi *tsi = platform_get_drvdata(pdev);
342 
343 	da9052_reg_write(tsi->da9052, DA9052_LDO9_REG, 0x19);
344 
345 	free_irq(tsi->irq_pendwn, tsi);
346 	free_irq(tsi->irq_datardy, tsi);
347 
348 	input_unregister_device(tsi->dev);
349 	kfree(tsi);
350 
351 	platform_set_drvdata(pdev, NULL);
352 
353 	return 0;
354 }
355 
356 static struct platform_driver da9052_tsi_driver = {
357 	.probe	= da9052_ts_probe,
358 	.remove	= __devexit_p(da9052_ts_remove),
359 	.driver	= {
360 		.name	= "da9052-tsi",
361 		.owner	= THIS_MODULE,
362 	},
363 };
364 
365 module_platform_driver(da9052_tsi_driver);
366 
367 MODULE_DESCRIPTION("Touchscreen driver for Dialog Semiconductor DA9052");
368 MODULE_AUTHOR("Anthony Olech <Anthony.Olech@diasemi.com>");
369 MODULE_LICENSE("GPL");
370 MODULE_ALIAS("platform:da9052-tsi");
371