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/delay.h>
32 #include <linux/interrupt.h>
33 #include <linux/platform_device.h>
34 #include <linux/clk.h>
35 #include <linux/io.h>
36
37 #include <plat/adc.h>
38 #include <plat/regs-adc.h>
39 #include <linux/platform_data/touchscreen-s3c2410.h>
40
41 #define TSC_SLEEP (S3C2410_ADCTSC_PULL_UP_DISABLE | S3C2410_ADCTSC_XY_PST(0))
42
43 #define INT_DOWN (0)
44 #define INT_UP (1 << 8)
45
46 #define WAIT4INT (S3C2410_ADCTSC_YM_SEN | \
47 S3C2410_ADCTSC_YP_SEN | \
48 S3C2410_ADCTSC_XP_SEN | \
49 S3C2410_ADCTSC_XY_PST(3))
50
51 #define AUTOPST (S3C2410_ADCTSC_YM_SEN | \
52 S3C2410_ADCTSC_YP_SEN | \
53 S3C2410_ADCTSC_XP_SEN | \
54 S3C2410_ADCTSC_AUTO_PST | \
55 S3C2410_ADCTSC_XY_PST(0))
56
57 #define FEAT_PEN_IRQ (1 << 0) /* HAS ADCCLRINTPNDNUP */
58
59 /* Per-touchscreen data. */
60
61 /**
62 * struct s3c2410ts - driver touchscreen state.
63 * @client: The ADC client we registered with the core driver.
64 * @dev: The device we are bound to.
65 * @input: The input device we registered with the input subsystem.
66 * @clock: The clock for the adc.
67 * @io: Pointer to the IO base.
68 * @xp: The accumulated X position data.
69 * @yp: The accumulated Y position data.
70 * @irq_tc: The interrupt number for pen up/down interrupt
71 * @count: The number of samples collected.
72 * @shift: The log2 of the maximum count to read in one go.
73 * @features: The features supported by the TSADC MOdule.
74 */
75 struct s3c2410ts {
76 struct s3c_adc_client *client;
77 struct device *dev;
78 struct input_dev *input;
79 struct clk *clock;
80 void __iomem *io;
81 unsigned long xp;
82 unsigned long yp;
83 int irq_tc;
84 int count;
85 int shift;
86 int features;
87 };
88
89 static struct s3c2410ts ts;
90
91 /**
92 * get_down - return the down state of the pen
93 * @data0: The data read from ADCDAT0 register.
94 * @data1: The data read from ADCDAT1 register.
95 *
96 * Return non-zero if both readings show that the pen is down.
97 */
get_down(unsigned long data0,unsigned long data1)98 static inline bool get_down(unsigned long data0, unsigned long data1)
99 {
100 /* returns true if both data values show stylus down */
101 return (!(data0 & S3C2410_ADCDAT0_UPDOWN) &&
102 !(data1 & S3C2410_ADCDAT0_UPDOWN));
103 }
104
touch_timer_fire(struct timer_list * unused)105 static void touch_timer_fire(struct timer_list *unused)
106 {
107 unsigned long data0;
108 unsigned long data1;
109 bool down;
110
111 data0 = readl(ts.io + S3C2410_ADCDAT0);
112 data1 = readl(ts.io + S3C2410_ADCDAT1);
113
114 down = get_down(data0, data1);
115
116 if (down) {
117 if (ts.count == (1 << ts.shift)) {
118 ts.xp >>= ts.shift;
119 ts.yp >>= ts.shift;
120
121 dev_dbg(ts.dev, "%s: X=%lu, Y=%lu, count=%d\n",
122 __func__, ts.xp, ts.yp, ts.count);
123
124 input_report_abs(ts.input, ABS_X, ts.xp);
125 input_report_abs(ts.input, ABS_Y, ts.yp);
126
127 input_report_key(ts.input, BTN_TOUCH, 1);
128 input_sync(ts.input);
129
130 ts.xp = 0;
131 ts.yp = 0;
132 ts.count = 0;
133 }
134
135 s3c_adc_start(ts.client, 0, 1 << ts.shift);
136 } else {
137 ts.xp = 0;
138 ts.yp = 0;
139 ts.count = 0;
140
141 input_report_key(ts.input, BTN_TOUCH, 0);
142 input_sync(ts.input);
143
144 writel(WAIT4INT | INT_DOWN, ts.io + S3C2410_ADCTSC);
145 }
146 }
147
148 static DEFINE_TIMER(touch_timer, touch_timer_fire);
149
150 /**
151 * stylus_irq - touchscreen stylus event interrupt
152 * @irq: The interrupt number
153 * @dev_id: The device ID.
154 *
155 * Called when the IRQ_TC is fired for a pen up or down event.
156 */
stylus_irq(int irq,void * dev_id)157 static irqreturn_t stylus_irq(int irq, void *dev_id)
158 {
159 unsigned long data0;
160 unsigned long data1;
161 bool down;
162
163 data0 = readl(ts.io + S3C2410_ADCDAT0);
164 data1 = readl(ts.io + S3C2410_ADCDAT1);
165
166 down = get_down(data0, data1);
167
168 /* TODO we should never get an interrupt with down set while
169 * the timer is running, but maybe we ought to verify that the
170 * timer isn't running anyways. */
171
172 if (down)
173 s3c_adc_start(ts.client, 0, 1 << ts.shift);
174 else
175 dev_dbg(ts.dev, "%s: count=%d\n", __func__, ts.count);
176
177 if (ts.features & FEAT_PEN_IRQ) {
178 /* Clear pen down/up interrupt */
179 writel(0x0, ts.io + S3C64XX_ADCCLRINTPNDNUP);
180 }
181
182 return IRQ_HANDLED;
183 }
184
185 /**
186 * s3c24xx_ts_conversion - ADC conversion callback
187 * @client: The client that was registered with the ADC core.
188 * @data0: The reading from ADCDAT0.
189 * @data1: The reading from ADCDAT1.
190 * @left: The number of samples left.
191 *
192 * Called when a conversion has finished.
193 */
s3c24xx_ts_conversion(struct s3c_adc_client * client,unsigned data0,unsigned data1,unsigned * left)194 static void s3c24xx_ts_conversion(struct s3c_adc_client *client,
195 unsigned data0, unsigned data1,
196 unsigned *left)
197 {
198 dev_dbg(ts.dev, "%s: %d,%d\n", __func__, data0, data1);
199
200 ts.xp += data0;
201 ts.yp += data1;
202
203 ts.count++;
204
205 /* From tests, it seems that it is unlikely to get a pen-up
206 * event during the conversion process which means we can
207 * ignore any pen-up events with less than the requisite
208 * count done.
209 *
210 * In several thousand conversions, no pen-ups where detected
211 * before count completed.
212 */
213 }
214
215 /**
216 * s3c24xx_ts_select - ADC selection callback.
217 * @client: The client that was registered with the ADC core.
218 * @select: The reason for select.
219 *
220 * Called when the ADC core selects (or deslects) us as a client.
221 */
s3c24xx_ts_select(struct s3c_adc_client * client,unsigned select)222 static void s3c24xx_ts_select(struct s3c_adc_client *client, unsigned select)
223 {
224 if (select) {
225 writel(S3C2410_ADCTSC_PULL_UP_DISABLE | AUTOPST,
226 ts.io + S3C2410_ADCTSC);
227 } else {
228 mod_timer(&touch_timer, jiffies+1);
229 writel(WAIT4INT | INT_UP, ts.io + S3C2410_ADCTSC);
230 }
231 }
232
233 /**
234 * s3c2410ts_probe - device core probe entry point
235 * @pdev: The device we are being bound to.
236 *
237 * Initialise, find and allocate any resources we need to run and then
238 * register with the ADC and input systems.
239 */
s3c2410ts_probe(struct platform_device * pdev)240 static int s3c2410ts_probe(struct platform_device *pdev)
241 {
242 struct s3c2410_ts_mach_info *info;
243 struct device *dev = &pdev->dev;
244 struct input_dev *input_dev;
245 struct resource *res;
246 int ret = -EINVAL;
247
248 /* Initialise input stuff */
249 memset(&ts, 0, sizeof(struct s3c2410ts));
250
251 ts.dev = dev;
252
253 info = dev_get_platdata(dev);
254 if (!info) {
255 dev_err(dev, "no platform data, cannot attach\n");
256 return -EINVAL;
257 }
258
259 dev_dbg(dev, "initialising touchscreen\n");
260
261 ts.clock = clk_get(dev, "adc");
262 if (IS_ERR(ts.clock)) {
263 dev_err(dev, "cannot get adc clock source\n");
264 return -ENOENT;
265 }
266
267 ret = clk_prepare_enable(ts.clock);
268 if (ret) {
269 dev_err(dev, "Failed! to enabled clocks\n");
270 goto err_clk_get;
271 }
272 dev_dbg(dev, "got and enabled clocks\n");
273
274 ts.irq_tc = ret = platform_get_irq(pdev, 0);
275 if (ret < 0) {
276 dev_err(dev, "no resource for interrupt\n");
277 goto err_clk;
278 }
279
280 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
281 if (!res) {
282 dev_err(dev, "no resource for registers\n");
283 ret = -ENOENT;
284 goto err_clk;
285 }
286
287 ts.io = ioremap(res->start, resource_size(res));
288 if (ts.io == NULL) {
289 dev_err(dev, "cannot map registers\n");
290 ret = -ENOMEM;
291 goto err_clk;
292 }
293
294 /* inititalise the gpio */
295 if (info->cfg_gpio)
296 info->cfg_gpio(to_platform_device(ts.dev));
297
298 ts.client = s3c_adc_register(pdev, s3c24xx_ts_select,
299 s3c24xx_ts_conversion, 1);
300 if (IS_ERR(ts.client)) {
301 dev_err(dev, "failed to register adc client\n");
302 ret = PTR_ERR(ts.client);
303 goto err_iomap;
304 }
305
306 /* Initialise registers */
307 if ((info->delay & 0xffff) > 0)
308 writel(info->delay & 0xffff, ts.io + S3C2410_ADCDLY);
309
310 writel(WAIT4INT | INT_DOWN, ts.io + S3C2410_ADCTSC);
311
312 input_dev = input_allocate_device();
313 if (!input_dev) {
314 dev_err(dev, "Unable to allocate the input device !!\n");
315 ret = -ENOMEM;
316 goto err_iomap;
317 }
318
319 ts.input = input_dev;
320 ts.input->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
321 ts.input->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
322 input_set_abs_params(ts.input, ABS_X, 0, 0x3FF, 0, 0);
323 input_set_abs_params(ts.input, ABS_Y, 0, 0x3FF, 0, 0);
324
325 ts.input->name = "S3C24XX TouchScreen";
326 ts.input->id.bustype = BUS_HOST;
327 ts.input->id.vendor = 0xDEAD;
328 ts.input->id.product = 0xBEEF;
329 ts.input->id.version = 0x0102;
330
331 ts.shift = info->oversampling_shift;
332 ts.features = platform_get_device_id(pdev)->driver_data;
333
334 ret = request_irq(ts.irq_tc, stylus_irq, 0,
335 "s3c2410_ts_pen", ts.input);
336 if (ret) {
337 dev_err(dev, "cannot get TC interrupt\n");
338 goto err_inputdev;
339 }
340
341 dev_info(dev, "driver attached, registering input device\n");
342
343 /* All went ok, so register to the input system */
344 ret = input_register_device(ts.input);
345 if (ret < 0) {
346 dev_err(dev, "failed to register input device\n");
347 ret = -EIO;
348 goto err_tcirq;
349 }
350
351 return 0;
352
353 err_tcirq:
354 free_irq(ts.irq_tc, ts.input);
355 err_inputdev:
356 input_free_device(ts.input);
357 err_iomap:
358 iounmap(ts.io);
359 err_clk:
360 clk_disable_unprepare(ts.clock);
361 del_timer_sync(&touch_timer);
362 err_clk_get:
363 clk_put(ts.clock);
364 return ret;
365 }
366
367 /**
368 * s3c2410ts_remove - device core removal entry point
369 * @pdev: The device we are being removed from.
370 *
371 * Free up our state ready to be removed.
372 */
s3c2410ts_remove(struct platform_device * pdev)373 static int s3c2410ts_remove(struct platform_device *pdev)
374 {
375 free_irq(ts.irq_tc, ts.input);
376 del_timer_sync(&touch_timer);
377
378 clk_disable_unprepare(ts.clock);
379 clk_put(ts.clock);
380
381 input_unregister_device(ts.input);
382 iounmap(ts.io);
383
384 return 0;
385 }
386
387 #ifdef CONFIG_PM
s3c2410ts_suspend(struct device * dev)388 static int s3c2410ts_suspend(struct device *dev)
389 {
390 writel(TSC_SLEEP, ts.io + S3C2410_ADCTSC);
391 disable_irq(ts.irq_tc);
392 clk_disable(ts.clock);
393
394 return 0;
395 }
396
s3c2410ts_resume(struct device * dev)397 static int s3c2410ts_resume(struct device *dev)
398 {
399 struct platform_device *pdev = to_platform_device(dev);
400 struct s3c2410_ts_mach_info *info = dev_get_platdata(&pdev->dev);
401
402 clk_enable(ts.clock);
403 enable_irq(ts.irq_tc);
404
405 /* Initialise registers */
406 if ((info->delay & 0xffff) > 0)
407 writel(info->delay & 0xffff, ts.io + S3C2410_ADCDLY);
408
409 writel(WAIT4INT | INT_DOWN, ts.io + S3C2410_ADCTSC);
410
411 return 0;
412 }
413
414 static const struct dev_pm_ops s3c_ts_pmops = {
415 .suspend = s3c2410ts_suspend,
416 .resume = s3c2410ts_resume,
417 };
418 #endif
419
420 static const struct platform_device_id s3cts_driver_ids[] = {
421 { "s3c2410-ts", 0 },
422 { "s3c2440-ts", 0 },
423 { "s3c64xx-ts", FEAT_PEN_IRQ },
424 { }
425 };
426 MODULE_DEVICE_TABLE(platform, s3cts_driver_ids);
427
428 static struct platform_driver s3c_ts_driver = {
429 .driver = {
430 .name = "samsung-ts",
431 #ifdef CONFIG_PM
432 .pm = &s3c_ts_pmops,
433 #endif
434 },
435 .id_table = s3cts_driver_ids,
436 .probe = s3c2410ts_probe,
437 .remove = s3c2410ts_remove,
438 };
439 module_platform_driver(s3c_ts_driver);
440
441 MODULE_AUTHOR("Arnaud Patard <arnaud.patard@rtp-net.org>, "
442 "Ben Dooks <ben@simtec.co.uk>, "
443 "Simtec Electronics <linux@simtec.co.uk>");
444 MODULE_DESCRIPTION("S3C24XX Touchscreen driver");
445 MODULE_LICENSE("GPL v2");
446
