1/*
2 * Samsung S3C24XX touchscreen driver
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the term of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17 *
18 * Copyright 2004 Arnaud Patard <arnaud.patard@rtp-net.org>
19 * Copyright 2008 Ben Dooks <ben-linux@fluff.org>
20 * Copyright 2009 Simtec Electronics <linux@simtec.co.uk>
21 *
22 * Additional work by Herbert Pötzl <herbert@13thfloor.at> and
23 * Harald Welte <laforge@openmoko.org>
24 */
25
26#include <linux/errno.h>
27#include <linux/kernel.h>
28#include <linux/module.h>
29#include <linux/gpio.h>
30#include <linux/input.h>
31#include <linux/init.h>
32#include <linux/delay.h>
33#include <linux/interrupt.h>
34#include <linux/platform_device.h>
35#include <linux/clk.h>
36#include <linux/io.h>
37
38#include <plat/adc.h>
39#include <plat/regs-adc.h>
40#include <plat/ts.h>
41
42#define TSC_SLEEP  (S3C2410_ADCTSC_PULL_UP_DISABLE | S3C2410_ADCTSC_XY_PST(0))
43
44#define INT_DOWN	(0)
45#define INT_UP		(1 << 8)
46
47#define WAIT4INT	(S3C2410_ADCTSC_YM_SEN | \
48			 S3C2410_ADCTSC_YP_SEN | \
49			 S3C2410_ADCTSC_XP_SEN | \
50			 S3C2410_ADCTSC_XY_PST(3))
51
52#define AUTOPST		(S3C2410_ADCTSC_YM_SEN | \
53			 S3C2410_ADCTSC_YP_SEN | \
54			 S3C2410_ADCTSC_XP_SEN | \
55			 S3C2410_ADCTSC_AUTO_PST | \
56			 S3C2410_ADCTSC_XY_PST(0))
57
58#define FEAT_PEN_IRQ	(1 << 0)	/* HAS ADCCLRINTPNDNUP */
59
60/* Per-touchscreen data. */
61
62/**
63 * struct s3c2410ts - driver touchscreen state.
64 * @client: The ADC client we registered with the core driver.
65 * @dev: The device we are bound to.
66 * @input: The input device we registered with the input subsystem.
67 * @clock: The clock for the adc.
68 * @io: Pointer to the IO base.
69 * @xp: The accumulated X position data.
70 * @yp: The accumulated Y position data.
71 * @irq_tc: The interrupt number for pen up/down interrupt
72 * @count: The number of samples collected.
73 * @shift: The log2 of the maximum count to read in one go.
74 * @features: The features supported by the TSADC MOdule.
75 */
76struct s3c2410ts {
77	struct s3c_adc_client *client;
78	struct device *dev;
79	struct input_dev *input;
80	struct clk *clock;
81	void __iomem *io;
82	unsigned long xp;
83	unsigned long yp;
84	int irq_tc;
85	int count;
86	int shift;
87	int features;
88};
89
90static struct s3c2410ts ts;
91
92/**
93 * get_down - return the down state of the pen
94 * @data0: The data read from ADCDAT0 register.
95 * @data1: The data read from ADCDAT1 register.
96 *
97 * Return non-zero if both readings show that the pen is down.
98 */
99static inline bool get_down(unsigned long data0, unsigned long data1)
100{
101	/* returns true if both data values show stylus down */
102	return (!(data0 & S3C2410_ADCDAT0_UPDOWN) &&
103		!(data1 & S3C2410_ADCDAT0_UPDOWN));
104}
105
106static void touch_timer_fire(unsigned long data)
107{
108	unsigned long data0;
109	unsigned long data1;
110	bool down;
111
112	data0 = readl(ts.io + S3C2410_ADCDAT0);
113	data1 = readl(ts.io + S3C2410_ADCDAT1);
114
115	down = get_down(data0, data1);
116
117	if (down) {
118		if (ts.count == (1 << ts.shift)) {
119			ts.xp >>= ts.shift;
120			ts.yp >>= ts.shift;
121
122			dev_dbg(ts.dev, "%s: X=%lu, Y=%lu, count=%d\n",
123				__func__, ts.xp, ts.yp, ts.count);
124
125			input_report_abs(ts.input, ABS_X, ts.xp);
126			input_report_abs(ts.input, ABS_Y, ts.yp);
127
128			input_report_key(ts.input, BTN_TOUCH, 1);
129			input_sync(ts.input);
130
131			ts.xp = 0;
132			ts.yp = 0;
133			ts.count = 0;
134		}
135
136		s3c_adc_start(ts.client, 0, 1 << ts.shift);
137	} else {
138		ts.xp = 0;
139		ts.yp = 0;
140		ts.count = 0;
141
142		input_report_key(ts.input, BTN_TOUCH, 0);
143		input_sync(ts.input);
144
145		writel(WAIT4INT | INT_DOWN, ts.io + S3C2410_ADCTSC);
146	}
147}
148
149static DEFINE_TIMER(touch_timer, touch_timer_fire, 0, 0);
150
151/**
152 * stylus_irq - touchscreen stylus event interrupt
153 * @irq: The interrupt number
154 * @dev_id: The device ID.
155 *
156 * Called when the IRQ_TC is fired for a pen up or down event.
157 */
158static irqreturn_t stylus_irq(int irq, void *dev_id)
159{
160	unsigned long data0;
161	unsigned long data1;
162	bool down;
163
164	data0 = readl(ts.io + S3C2410_ADCDAT0);
165	data1 = readl(ts.io + S3C2410_ADCDAT1);
166
167	down = get_down(data0, data1);
168
169	/* TODO we should never get an interrupt with down set while
170	 * the timer is running, but maybe we ought to verify that the
171	 * timer isn't running anyways. */
172
173	if (down)
174		s3c_adc_start(ts.client, 0, 1 << ts.shift);
175	else
176		dev_dbg(ts.dev, "%s: count=%d\n", __func__, ts.count);
177
178	if (ts.features & FEAT_PEN_IRQ) {
179		/* Clear pen down/up interrupt */
180		writel(0x0, ts.io + S3C64XX_ADCCLRINTPNDNUP);
181	}
182
183	return IRQ_HANDLED;
184}
185
186/**
187 * s3c24xx_ts_conversion - ADC conversion callback
188 * @client: The client that was registered with the ADC core.
189 * @data0: The reading from ADCDAT0.
190 * @data1: The reading from ADCDAT1.
191 * @left: The number of samples left.
192 *
193 * Called when a conversion has finished.
194 */
195static void s3c24xx_ts_conversion(struct s3c_adc_client *client,
196				  unsigned data0, unsigned data1,
197				  unsigned *left)
198{
199	dev_dbg(ts.dev, "%s: %d,%d\n", __func__, data0, data1);
200
201	ts.xp += data0;
202	ts.yp += data1;
203
204	ts.count++;
205
206	/* From tests, it seems that it is unlikely to get a pen-up
207	 * event during the conversion process which means we can
208	 * ignore any pen-up events with less than the requisite
209	 * count done.
210	 *
211	 * In several thousand conversions, no pen-ups where detected
212	 * before count completed.
213	 */
214}
215
216/**
217 * s3c24xx_ts_select - ADC selection callback.
218 * @client: The client that was registered with the ADC core.
219 * @select: The reason for select.
220 *
221 * Called when the ADC core selects (or deslects) us as a client.
222 */
223static void s3c24xx_ts_select(struct s3c_adc_client *client, unsigned select)
224{
225	if (select) {
226		writel(S3C2410_ADCTSC_PULL_UP_DISABLE | AUTOPST,
227		       ts.io + S3C2410_ADCTSC);
228	} else {
229		mod_timer(&touch_timer, jiffies+1);
230		writel(WAIT4INT | INT_UP, ts.io + S3C2410_ADCTSC);
231	}
232}
233
234/**
235 * s3c2410ts_probe - device core probe entry point
236 * @pdev: The device we are being bound to.
237 *
238 * Initialise, find and allocate any resources we need to run and then
239 * register with the ADC and input systems.
240 */
241static int __devinit s3c2410ts_probe(struct platform_device *pdev)
242{
243	struct s3c2410_ts_mach_info *info;
244	struct device *dev = &pdev->dev;
245	struct input_dev *input_dev;
246	struct resource *res;
247	int ret = -EINVAL;
248
249	/* Initialise input stuff */
250	memset(&ts, 0, sizeof(struct s3c2410ts));
251
252	ts.dev = dev;
253
254	info = pdev->dev.platform_data;
255	if (!info) {
256		dev_err(dev, "no platform data, cannot attach\n");
257		return -EINVAL;
258	}
259
260	dev_dbg(dev, "initialising touchscreen\n");
261
262	ts.clock = clk_get(dev, "adc");
263	if (IS_ERR(ts.clock)) {
264		dev_err(dev, "cannot get adc clock source\n");
265		return -ENOENT;
266	}
267
268	clk_enable(ts.clock);
269	dev_dbg(dev, "got and enabled clocks\n");
270
271	ts.irq_tc = ret = platform_get_irq(pdev, 0);
272	if (ret < 0) {
273		dev_err(dev, "no resource for interrupt\n");
274		goto err_clk;
275	}
276
277	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
278	if (!res) {
279		dev_err(dev, "no resource for registers\n");
280		ret = -ENOENT;
281		goto err_clk;
282	}
283
284	ts.io = ioremap(res->start, resource_size(res));
285	if (ts.io == NULL) {
286		dev_err(dev, "cannot map registers\n");
287		ret = -ENOMEM;
288		goto err_clk;
289	}
290
291	/* inititalise the gpio */
292	if (info->cfg_gpio)
293		info->cfg_gpio(to_platform_device(ts.dev));
294
295	ts.client = s3c_adc_register(pdev, s3c24xx_ts_select,
296				     s3c24xx_ts_conversion, 1);
297	if (IS_ERR(ts.client)) {
298		dev_err(dev, "failed to register adc client\n");
299		ret = PTR_ERR(ts.client);
300		goto err_iomap;
301	}
302
303	/* Initialise registers */
304	if ((info->delay & 0xffff) > 0)
305		writel(info->delay & 0xffff, ts.io + S3C2410_ADCDLY);
306
307	writel(WAIT4INT | INT_DOWN, ts.io + S3C2410_ADCTSC);
308
309	input_dev = input_allocate_device();
310	if (!input_dev) {
311		dev_err(dev, "Unable to allocate the input device !!\n");
312		ret = -ENOMEM;
313		goto err_iomap;
314	}
315
316	ts.input = input_dev;
317	ts.input->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
318	ts.input->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
319	input_set_abs_params(ts.input, ABS_X, 0, 0x3FF, 0, 0);
320	input_set_abs_params(ts.input, ABS_Y, 0, 0x3FF, 0, 0);
321
322	ts.input->name = "S3C24XX TouchScreen";
323	ts.input->id.bustype = BUS_HOST;
324	ts.input->id.vendor = 0xDEAD;
325	ts.input->id.product = 0xBEEF;
326	ts.input->id.version = 0x0102;
327
328	ts.shift = info->oversampling_shift;
329	ts.features = platform_get_device_id(pdev)->driver_data;
330
331	ret = request_irq(ts.irq_tc, stylus_irq, 0,
332			  "s3c2410_ts_pen", ts.input);
333	if (ret) {
334		dev_err(dev, "cannot get TC interrupt\n");
335		goto err_inputdev;
336	}
337
338	dev_info(dev, "driver attached, registering input device\n");
339
340	/* All went ok, so register to the input system */
341	ret = input_register_device(ts.input);
342	if (ret < 0) {
343		dev_err(dev, "failed to register input device\n");
344		ret = -EIO;
345		goto err_tcirq;
346	}
347
348	return 0;
349
350 err_tcirq:
351	free_irq(ts.irq_tc, ts.input);
352 err_inputdev:
353	input_free_device(ts.input);
354 err_iomap:
355	iounmap(ts.io);
356 err_clk:
357	del_timer_sync(&touch_timer);
358	clk_put(ts.clock);
359	return ret;
360}
361
362/**
363 * s3c2410ts_remove - device core removal entry point
364 * @pdev: The device we are being removed from.
365 *
366 * Free up our state ready to be removed.
367 */
368static int __devexit s3c2410ts_remove(struct platform_device *pdev)
369{
370	free_irq(ts.irq_tc, ts.input);
371	del_timer_sync(&touch_timer);
372
373	clk_disable(ts.clock);
374	clk_put(ts.clock);
375
376	input_unregister_device(ts.input);
377	iounmap(ts.io);
378
379	return 0;
380}
381
382#ifdef CONFIG_PM
383static int s3c2410ts_suspend(struct device *dev)
384{
385	writel(TSC_SLEEP, ts.io + S3C2410_ADCTSC);
386	disable_irq(ts.irq_tc);
387	clk_disable(ts.clock);
388
389	return 0;
390}
391
392static int s3c2410ts_resume(struct device *dev)
393{
394	struct platform_device *pdev = to_platform_device(dev);
395	struct s3c2410_ts_mach_info *info = pdev->dev.platform_data;
396
397	clk_enable(ts.clock);
398	enable_irq(ts.irq_tc);
399
400	/* Initialise registers */
401	if ((info->delay & 0xffff) > 0)
402		writel(info->delay & 0xffff, ts.io + S3C2410_ADCDLY);
403
404	writel(WAIT4INT | INT_DOWN, ts.io + S3C2410_ADCTSC);
405
406	return 0;
407}
408
409static struct dev_pm_ops s3c_ts_pmops = {
410	.suspend	= s3c2410ts_suspend,
411	.resume		= s3c2410ts_resume,
412};
413#endif
414
415static struct platform_device_id s3cts_driver_ids[] = {
416	{ "s3c2410-ts", 0 },
417	{ "s3c2440-ts", 0 },
418	{ "s3c64xx-ts", FEAT_PEN_IRQ },
419	{ }
420};
421MODULE_DEVICE_TABLE(platform, s3cts_driver_ids);
422
423static struct platform_driver s3c_ts_driver = {
424	.driver         = {
425		.name   = "samsung-ts",
426		.owner  = THIS_MODULE,
427#ifdef CONFIG_PM
428		.pm	= &s3c_ts_pmops,
429#endif
430	},
431	.id_table	= s3cts_driver_ids,
432	.probe		= s3c2410ts_probe,
433	.remove		= __devexit_p(s3c2410ts_remove),
434};
435module_platform_driver(s3c_ts_driver);
436
437MODULE_AUTHOR("Arnaud Patard <arnaud.patard@rtp-net.org>, "
438	      "Ben Dooks <ben@simtec.co.uk>, "
439	      "Simtec Electronics <linux@simtec.co.uk>");
440MODULE_DESCRIPTION("S3C24XX Touchscreen driver");
441MODULE_LICENSE("GPL v2");
442