2 * Samsung S3C24XX touchscreen driver
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.
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.
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
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>
22 * Additional work by Herbert Pƶtzl <herbert@13thfloor.at> and
23 * Harald Welte <laforge@openmoko.org>
26 #include <linux/errno.h>
27 #include <linux/kernel.h>
28 #include <linux/module.h>
29 #include <linux/slab.h>
30 #include <linux/gpio.h>
31 #include <linux/input.h>
32 #include <linux/init.h>
33 #include <linux/delay.h>
34 #include <linux/interrupt.h>
35 #include <linux/platform_device.h>
36 #include <linux/clk.h>
40 #include <plat/regs-adc.h>
42 #include <mach/regs-gpio.h>
45 #define TSC_SLEEP (S3C2410_ADCTSC_PULL_UP_DISABLE | S3C2410_ADCTSC_XY_PST(0))
48 #define INT_UP (1 << 8)
50 #define WAIT4INT (S3C2410_ADCTSC_YM_SEN | \
51 S3C2410_ADCTSC_YP_SEN | \
52 S3C2410_ADCTSC_XP_SEN | \
53 S3C2410_ADCTSC_XY_PST(3))
55 #define AUTOPST (S3C2410_ADCTSC_YM_SEN | \
56 S3C2410_ADCTSC_YP_SEN | \
57 S3C2410_ADCTSC_XP_SEN | \
58 S3C2410_ADCTSC_AUTO_PST | \
59 S3C2410_ADCTSC_XY_PST(0))
61 /* Per-touchscreen data. */
64 * struct s3c2410ts - driver touchscreen state.
65 * @client: The ADC client we registered with the core driver.
66 * @dev: The device we are bound to.
67 * @input: The input device we registered with the input subsystem.
68 * @clock: The clock for the adc.
69 * @io: Pointer to the IO base.
70 * @xp: The accumulated X position data.
71 * @yp: The accumulated Y position data.
72 * @irq_tc: The interrupt number for pen up/down interrupt
73 * @count: The number of samples collected.
74 * @shift: The log2 of the maximum count to read in one go.
77 struct s3c_adc_client *client;
79 struct input_dev *input;
89 static struct s3c2410ts ts;
92 * s3c2410_ts_connect - configure gpio for s3c2410 systems
94 * Configure the GPIO for the S3C2410 system, where we have external FETs
95 * connected to the device (later systems such as the S3C2440 integrate
96 * these into the device).
98 static inline void s3c2410_ts_connect(void)
100 s3c2410_gpio_cfgpin(S3C2410_GPG(12), S3C2410_GPG12_XMON);
101 s3c2410_gpio_cfgpin(S3C2410_GPG(13), S3C2410_GPG13_nXPON);
102 s3c2410_gpio_cfgpin(S3C2410_GPG(14), S3C2410_GPG14_YMON);
103 s3c2410_gpio_cfgpin(S3C2410_GPG(15), S3C2410_GPG15_nYPON);
107 * get_down - return the down state of the pen
108 * @data0: The data read from ADCDAT0 register.
109 * @data1: The data read from ADCDAT1 register.
111 * Return non-zero if both readings show that the pen is down.
113 static inline bool get_down(unsigned long data0, unsigned long data1)
115 /* returns true if both data values show stylus down */
116 return (!(data0 & S3C2410_ADCDAT0_UPDOWN) &&
117 !(data1 & S3C2410_ADCDAT0_UPDOWN));
120 static void touch_timer_fire(unsigned long data)
126 data0 = readl(ts.io + S3C2410_ADCDAT0);
127 data1 = readl(ts.io + S3C2410_ADCDAT1);
129 down = get_down(data0, data1);
132 if (ts.count == (1 << ts.shift)) {
136 dev_dbg(ts.dev, "%s: X=%lu, Y=%lu, count=%d\n",
137 __func__, ts.xp, ts.yp, ts.count);
139 input_report_abs(ts.input, ABS_X, ts.xp);
140 input_report_abs(ts.input, ABS_Y, ts.yp);
142 input_report_key(ts.input, BTN_TOUCH, 1);
143 input_sync(ts.input);
150 s3c_adc_start(ts.client, 0, 1 << ts.shift);
156 input_report_key(ts.input, BTN_TOUCH, 0);
157 input_sync(ts.input);
159 writel(WAIT4INT | INT_DOWN, ts.io + S3C2410_ADCTSC);
163 static DEFINE_TIMER(touch_timer, touch_timer_fire, 0, 0);
166 * stylus_irq - touchscreen stylus event interrupt
167 * @irq: The interrupt number
168 * @dev_id: The device ID.
170 * Called when the IRQ_TC is fired for a pen up or down event.
172 static irqreturn_t stylus_irq(int irq, void *dev_id)
178 data0 = readl(ts.io + S3C2410_ADCDAT0);
179 data1 = readl(ts.io + S3C2410_ADCDAT1);
181 down = get_down(data0, data1);
183 /* TODO we should never get an interrupt with down set while
184 * the timer is running, but maybe we ought to verify that the
185 * timer isn't running anyways. */
188 s3c_adc_start(ts.client, 0, 1 << ts.shift);
190 dev_info(ts.dev, "%s: count=%d\n", __func__, ts.count);
196 * s3c24xx_ts_conversion - ADC conversion callback
197 * @client: The client that was registered with the ADC core.
198 * @data0: The reading from ADCDAT0.
199 * @data1: The reading from ADCDAT1.
200 * @left: The number of samples left.
202 * Called when a conversion has finished.
204 static void s3c24xx_ts_conversion(struct s3c_adc_client *client,
205 unsigned data0, unsigned data1,
208 dev_dbg(ts.dev, "%s: %d,%d\n", __func__, data0, data1);
215 /* From tests, it seems that it is unlikely to get a pen-up
216 * event during the conversion process which means we can
217 * ignore any pen-up events with less than the requisite
220 * In several thousand conversions, no pen-ups where detected
221 * before count completed.
226 * s3c24xx_ts_select - ADC selection callback.
227 * @client: The client that was registered with the ADC core.
228 * @select: The reason for select.
230 * Called when the ADC core selects (or deslects) us as a client.
232 static void s3c24xx_ts_select(struct s3c_adc_client *client, unsigned select)
235 writel(S3C2410_ADCTSC_PULL_UP_DISABLE | AUTOPST,
236 ts.io + S3C2410_ADCTSC);
238 mod_timer(&touch_timer, jiffies+1);
239 writel(WAIT4INT | INT_UP, ts.io + S3C2410_ADCTSC);
244 * s3c2410ts_probe - device core probe entry point
245 * @pdev: The device we are being bound to.
247 * Initialise, find and allocate any resources we need to run and then
248 * register with the ADC and input systems.
250 static int __devinit s3c2410ts_probe(struct platform_device *pdev)
252 struct s3c2410_ts_mach_info *info;
253 struct device *dev = &pdev->dev;
254 struct input_dev *input_dev;
255 struct resource *res;
258 /* Initialise input stuff */
259 memset(&ts, 0, sizeof(struct s3c2410ts));
263 info = pdev->dev.platform_data;
265 dev_err(dev, "no platform data, cannot attach\n");
269 dev_dbg(dev, "initialising touchscreen\n");
271 ts.clock = clk_get(dev, "adc");
272 if (IS_ERR(ts.clock)) {
273 dev_err(dev, "cannot get adc clock source\n");
277 clk_enable(ts.clock);
278 dev_dbg(dev, "got and enabled clocks\n");
280 ts.irq_tc = ret = platform_get_irq(pdev, 0);
282 dev_err(dev, "no resource for interrupt\n");
286 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
288 dev_err(dev, "no resource for registers\n");
293 ts.io = ioremap(res->start, resource_size(res));
295 dev_err(dev, "cannot map registers\n");
300 /* Configure the touchscreen external FETs on the S3C2410 */
301 if (!platform_get_device_id(pdev)->driver_data)
302 s3c2410_ts_connect();
304 ts.client = s3c_adc_register(pdev, s3c24xx_ts_select,
305 s3c24xx_ts_conversion, 1);
306 if (IS_ERR(ts.client)) {
307 dev_err(dev, "failed to register adc client\n");
308 ret = PTR_ERR(ts.client);
312 /* Initialise registers */
313 if ((info->delay & 0xffff) > 0)
314 writel(info->delay & 0xffff, ts.io + S3C2410_ADCDLY);
316 writel(WAIT4INT | INT_DOWN, ts.io + S3C2410_ADCTSC);
318 input_dev = input_allocate_device();
320 dev_err(dev, "Unable to allocate the input device !!\n");
325 ts.input = input_dev;
326 ts.input->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
327 ts.input->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
328 input_set_abs_params(ts.input, ABS_X, 0, 0x3FF, 0, 0);
329 input_set_abs_params(ts.input, ABS_Y, 0, 0x3FF, 0, 0);
331 ts.input->name = "S3C24XX TouchScreen";
332 ts.input->id.bustype = BUS_HOST;
333 ts.input->id.vendor = 0xDEAD;
334 ts.input->id.product = 0xBEEF;
335 ts.input->id.version = 0x0102;
337 ts.shift = info->oversampling_shift;
339 ret = request_irq(ts.irq_tc, stylus_irq, IRQF_DISABLED,
340 "s3c2410_ts_pen", ts.input);
342 dev_err(dev, "cannot get TC interrupt\n");
346 dev_info(dev, "driver attached, registering input device\n");
348 /* All went ok, so register to the input system */
349 ret = input_register_device(ts.input);
351 dev_err(dev, "failed to register input device\n");
359 free_irq(ts.irq_tc, ts.input);
361 input_unregister_device(ts.input);
365 del_timer_sync(&touch_timer);
371 * s3c2410ts_remove - device core removal entry point
372 * @pdev: The device we are being removed from.
374 * Free up our state ready to be removed.
376 static int __devexit s3c2410ts_remove(struct platform_device *pdev)
378 free_irq(ts.irq_tc, ts.input);
379 del_timer_sync(&touch_timer);
381 clk_disable(ts.clock);
384 input_unregister_device(ts.input);
391 static int s3c2410ts_suspend(struct device *dev)
393 writel(TSC_SLEEP, ts.io + S3C2410_ADCTSC);
394 disable_irq(ts.irq_tc);
395 clk_disable(ts.clock);
400 static int s3c2410ts_resume(struct device *dev)
402 struct platform_device *pdev = to_platform_device(dev);
403 struct s3c2410_ts_mach_info *info = pdev->dev.platform_data;
405 clk_enable(ts.clock);
406 enable_irq(ts.irq_tc);
408 /* Initialise registers */
409 if ((info->delay & 0xffff) > 0)
410 writel(info->delay & 0xffff, ts.io + S3C2410_ADCDLY);
412 writel(WAIT4INT | INT_DOWN, ts.io + S3C2410_ADCTSC);
417 static struct dev_pm_ops s3c_ts_pmops = {
418 .suspend = s3c2410ts_suspend,
419 .resume = s3c2410ts_resume,
423 static struct platform_device_id s3cts_driver_ids[] = {
428 MODULE_DEVICE_TABLE(platform, s3cts_driver_ids);
430 static struct platform_driver s3c_ts_driver = {
432 .name = "s3c24xx-ts",
433 .owner = THIS_MODULE,
438 .id_table = s3cts_driver_ids,
439 .probe = s3c2410ts_probe,
440 .remove = __devexit_p(s3c2410ts_remove),
443 static int __init s3c2410ts_init(void)
445 return platform_driver_register(&s3c_ts_driver);
448 static void __exit s3c2410ts_exit(void)
450 platform_driver_unregister(&s3c_ts_driver);
453 module_init(s3c2410ts_init);
454 module_exit(s3c2410ts_exit);
456 MODULE_AUTHOR("Arnaud Patard <arnaud.patard@rtp-net.org>, "
457 "Ben Dooks <ben@simtec.co.uk>, "
458 "Simtec Electronics <linux@simtec.co.uk>");
459 MODULE_DESCRIPTION("S3C24XX Touchscreen driver");
460 MODULE_LICENSE("GPL v2");