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
);
131 if (ts
.count
== (1 << ts
.shift
)) {
135 dev_dbg(ts
.dev
, "%s: X=%lu, Y=%lu, count=%d\n",
136 __func__
, ts
.xp
, ts
.yp
, ts
.count
);
138 input_report_abs(ts
.input
, ABS_X
, ts
.xp
);
139 input_report_abs(ts
.input
, ABS_Y
, ts
.yp
);
141 input_report_key(ts
.input
, BTN_TOUCH
, 1);
142 input_sync(ts
.input
);
150 s3c_adc_start(ts
.client
, 0, 1 << ts
.shift
);
154 input_report_key(ts
.input
, BTN_TOUCH
, 0);
155 input_sync(ts
.input
);
157 writel(WAIT4INT
| INT_DOWN
, ts
.io
+ S3C2410_ADCTSC
);
161 static DEFINE_TIMER(touch_timer
, touch_timer_fire
, 0, 0);
164 * stylus_irq - touchscreen stylus event interrupt
165 * @irq: The interrupt number
166 * @dev_id: The device ID.
168 * Called when the IRQ_TC is fired for a pen up or down event.
170 static irqreturn_t
stylus_irq(int irq
, void *dev_id
)
176 data0
= readl(ts
.io
+ S3C2410_ADCDAT0
);
177 data1
= readl(ts
.io
+ S3C2410_ADCDAT1
);
179 down
= get_down(data0
, data1
);
181 /* TODO we should never get an interrupt with down set while
182 * the timer is running, but maybe we ought to verify that the
183 * timer isn't running anyways. */
186 s3c_adc_start(ts
.client
, 0, 1 << ts
.shift
);
188 dev_info(ts
.dev
, "%s: count=%d\n", __func__
, ts
.count
);
194 * s3c24xx_ts_conversion - ADC conversion callback
195 * @client: The client that was registered with the ADC core.
196 * @data0: The reading from ADCDAT0.
197 * @data1: The reading from ADCDAT1.
198 * @left: The number of samples left.
200 * Called when a conversion has finished.
202 static void s3c24xx_ts_conversion(struct s3c_adc_client
*client
,
203 unsigned data0
, unsigned data1
,
206 dev_dbg(ts
.dev
, "%s: %d,%d\n", __func__
, data0
, data1
);
213 /* From tests, it seems that it is unlikely to get a pen-up
214 * event during the conversion process which means we can
215 * ignore any pen-up events with less than the requisite
218 * In several thousand conversions, no pen-ups where detected
219 * before count completed.
224 * s3c24xx_ts_select - ADC selection callback.
225 * @client: The client that was registered with the ADC core.
226 * @select: The reason for select.
228 * Called when the ADC core selects (or deslects) us as a client.
230 static void s3c24xx_ts_select(struct s3c_adc_client
*client
, unsigned select
)
233 writel(S3C2410_ADCTSC_PULL_UP_DISABLE
| AUTOPST
,
234 ts
.io
+ S3C2410_ADCTSC
);
236 mod_timer(&touch_timer
, jiffies
+1);
237 writel(WAIT4INT
| INT_UP
, ts
.io
+ S3C2410_ADCTSC
);
242 * s3c2410ts_probe - device core probe entry point
243 * @pdev: The device we are being bound to.
245 * Initialise, find and allocate any resources we need to run and then
246 * register with the ADC and input systems.
248 static int __devinit
s3c2410ts_probe(struct platform_device
*pdev
)
250 struct s3c2410_ts_mach_info
*info
;
251 struct device
*dev
= &pdev
->dev
;
252 struct input_dev
*input_dev
;
253 struct resource
*res
;
256 /* Initialise input stuff */
257 memset(&ts
, 0, sizeof(struct s3c2410ts
));
261 info
= pdev
->dev
.platform_data
;
263 dev_err(dev
, "no platform data, cannot attach\n");
267 dev_dbg(dev
, "initialising touchscreen\n");
269 ts
.clock
= clk_get(dev
, "adc");
270 if (IS_ERR(ts
.clock
)) {
271 dev_err(dev
, "cannot get adc clock source\n");
275 clk_enable(ts
.clock
);
276 dev_dbg(dev
, "got and enabled clocks\n");
278 ts
.irq_tc
= ret
= platform_get_irq(pdev
, 0);
280 dev_err(dev
, "no resource for interrupt\n");
284 res
= platform_get_resource(pdev
, IORESOURCE_MEM
, 0);
286 dev_err(dev
, "no resource for registers\n");
291 ts
.io
= ioremap(res
->start
, resource_size(res
));
293 dev_err(dev
, "cannot map registers\n");
298 /* Configure the touchscreen external FETs on the S3C2410 */
299 if (!platform_get_device_id(pdev
)->driver_data
)
300 s3c2410_ts_connect();
302 ts
.client
= s3c_adc_register(pdev
, s3c24xx_ts_select
,
303 s3c24xx_ts_conversion
, 1);
304 if (IS_ERR(ts
.client
)) {
305 dev_err(dev
, "failed to register adc client\n");
306 ret
= PTR_ERR(ts
.client
);
310 /* Initialise registers */
311 if ((info
->delay
& 0xffff) > 0)
312 writel(info
->delay
& 0xffff, ts
.io
+ S3C2410_ADCDLY
);
314 writel(WAIT4INT
| INT_DOWN
, ts
.io
+ S3C2410_ADCTSC
);
316 input_dev
= input_allocate_device();
318 dev_err(dev
, "Unable to allocate the input device !!\n");
323 ts
.input
= input_dev
;
324 ts
.input
->evbit
[0] = BIT_MASK(EV_KEY
) | BIT_MASK(EV_ABS
);
325 ts
.input
->keybit
[BIT_WORD(BTN_TOUCH
)] = BIT_MASK(BTN_TOUCH
);
326 input_set_abs_params(ts
.input
, ABS_X
, 0, 0x3FF, 0, 0);
327 input_set_abs_params(ts
.input
, ABS_Y
, 0, 0x3FF, 0, 0);
329 ts
.input
->name
= "S3C24XX TouchScreen";
330 ts
.input
->id
.bustype
= BUS_HOST
;
331 ts
.input
->id
.vendor
= 0xDEAD;
332 ts
.input
->id
.product
= 0xBEEF;
333 ts
.input
->id
.version
= 0x0102;
335 ts
.shift
= info
->oversampling_shift
;
337 ret
= request_irq(ts
.irq_tc
, stylus_irq
, IRQF_DISABLED
,
338 "s3c2410_ts_pen", ts
.input
);
340 dev_err(dev
, "cannot get TC interrupt\n");
344 dev_info(dev
, "driver attached, registering input device\n");
346 /* All went ok, so register to the input system */
347 ret
= input_register_device(ts
.input
);
349 dev_err(dev
, "failed to register input device\n");
357 free_irq(ts
.irq_tc
, ts
.input
);
359 input_unregister_device(ts
.input
);
363 del_timer_sync(&touch_timer
);
369 * s3c2410ts_remove - device core removal entry point
370 * @pdev: The device we are being removed from.
372 * Free up our state ready to be removed.
374 static int __devexit
s3c2410ts_remove(struct platform_device
*pdev
)
376 free_irq(ts
.irq_tc
, ts
.input
);
377 del_timer_sync(&touch_timer
);
379 clk_disable(ts
.clock
);
382 input_unregister_device(ts
.input
);
389 static int s3c2410ts_suspend(struct device
*dev
)
391 writel(TSC_SLEEP
, ts
.io
+ S3C2410_ADCTSC
);
392 disable_irq(ts
.irq_tc
);
393 clk_disable(ts
.clock
);
398 static int s3c2410ts_resume(struct device
*dev
)
400 struct platform_device
*pdev
= to_platform_device(dev
);
401 struct s3c2410_ts_mach_info
*info
= pdev
->dev
.platform_data
;
403 clk_enable(ts
.clock
);
405 /* Initialise registers */
406 if ((info
->delay
& 0xffff) > 0)
407 writel(info
->delay
& 0xffff, ts
.io
+ S3C2410_ADCDLY
);
409 writel(WAIT4INT
| INT_DOWN
, ts
.io
+ S3C2410_ADCTSC
);
414 static struct dev_pm_ops s3c_ts_pmops
= {
415 .suspend
= s3c2410ts_suspend
,
416 .resume
= s3c2410ts_resume
,
420 static struct platform_device_id s3cts_driver_ids
[] = {
425 MODULE_DEVICE_TABLE(platform
, s3cts_driver_ids
);
427 static struct platform_driver s3c_ts_driver
= {
429 .name
= "s3c24xx-ts",
430 .owner
= THIS_MODULE
,
435 .id_table
= s3cts_driver_ids
,
436 .probe
= s3c2410ts_probe
,
437 .remove
= __devexit_p(s3c2410ts_remove
),
440 static int __init
s3c2410ts_init(void)
442 return platform_driver_register(&s3c_ts_driver
);
445 static void __exit
s3c2410ts_exit(void)
447 platform_driver_unregister(&s3c_ts_driver
);
450 module_init(s3c2410ts_init
);
451 module_exit(s3c2410ts_exit
);
453 MODULE_AUTHOR("Arnaud Patard <arnaud.patard@rtp-net.org>, "
454 "Ben Dooks <ben@simtec.co.uk>, "
455 "Simtec Electronics <linux@simtec.co.uk>");
456 MODULE_DESCRIPTION("S3C24XX Touchscreen driver");
457 MODULE_LICENSE("GPL v2");