f37836d998eb3af95fe42ae2a17bb212243144d0
[openwrt.git] / target / linux / ep93xx / patches-3.3 / 003-ep93xx_touchscreen.patch
1 ---
2  arch/arm/mach-ep93xx/include/mach/hardware.h   |    1 
3  arch/arm/mach-ep93xx/include/mach/regs_touch.h |   95 ++
4  drivers/input/touchscreen/Kconfig              |    5 
5  drivers/input/touchscreen/Makefile             |    1 
6  drivers/input/touchscreen/ep93xx_ts.c          | 1117 +++++++++++++++++++++++++
7  drivers/input/touchscreen/ep93xx_ts.h          |   53 +
8  6 files changed, 1272 insertions(+)
9
10 --- a/drivers/input/touchscreen/Kconfig
11 +++ b/drivers/input/touchscreen/Kconfig
12 @@ -200,6 +200,15 @@ config TOUCHSCREEN_EGALAX
13           To compile this driver as a module, choose M here: the
14           module will be called egalax_ts.
15  
16 +config TOUCHSCREEN_EP93XX
17 +       tristate "EP93xx Touchscreen"
18 +       depends on ARM && INPUT && ARCH_EP93XX
19 +       help
20 +         Say Y here to enable support for EP93xx touch screen.
21 +
22 +         To compile this driver as a module, choose M here:
23 +         the module will be called ep93xx_ts.
24 +
25  config TOUCHSCREEN_FUJITSU
26         tristate "Fujitsu serial touchscreen"
27         select SERIO
28 --- a/drivers/input/touchscreen/Makefile
29 +++ b/drivers/input/touchscreen/Makefile
30 @@ -25,6 +25,7 @@ obj-$(CONFIG_TOUCHSCREEN_GUNZE)               += gunz
31  obj-$(CONFIG_TOUCHSCREEN_EETI)         += eeti_ts.o
32  obj-$(CONFIG_TOUCHSCREEN_ELO)          += elo.o
33  obj-$(CONFIG_TOUCHSCREEN_EGALAX)       += egalax_ts.o
34 +obj-$(CONFIG_TOUCHSCREEN_EP93XX)       += ep93xx_ts.o
35  obj-$(CONFIG_TOUCHSCREEN_FUJITSU)      += fujitsu_ts.o
36  obj-$(CONFIG_TOUCHSCREEN_INEXIO)       += inexio.o
37  obj-$(CONFIG_TOUCHSCREEN_INTEL_MID)    += intel-mid-touch.o
38 --- /dev/null
39 +++ b/drivers/input/touchscreen/ep93xx_ts.c
40 @@ -0,0 +1,1021 @@
41 +/*
42 + * linux/drivers/input/touchscreen/ep93xx_ts.c
43 + *
44 + * Copyright (C) 2003-2004 Cirrus Corp.
45 + *
46 + * This program is free software; you can redistribute it and/or modify
47 + * it under the terms of the GNU General Public License version 2 as
48 + * published by the Free Software Foundation.
49 + */
50 +
51 +#include <linux/module.h>
52 +#include <linux/types.h>
53 +#include <linux/delay.h>
54 +#include <linux/wait.h>
55 +#include <linux/fs.h>
56 +#include <linux/sched.h>
57 +#include <linux/poll.h>
58 +#include <linux/miscdevice.h>
59 +#include <linux/init.h>
60 +#include <linux/compiler.h>
61 +#include <linux/timer.h>
62 +#include <linux/interrupt.h>
63 +#include <linux/syscalls.h>
64 +#include <linux/input.h>
65 +#include <linux/semaphore.h>
66 +#include <asm/irq.h>
67 +#include <mach/hardware.h>
68 +#include <asm/io.h>
69 +
70 +/* This stuff should be in ep93xx-regs.h */
71 +#define EP93XX_TOUCHSCREEN_REG(x)      (EP93XX_TOUCHSCREEN_BASE + (x))
72 +/* R/W touchscreen controller setup control register. */
73 +#define EP93XX_TOUCHSCREEN_SETUP       EP93XX_TOUCHSCREEN_REG(0x00)
74 +/* R/W touchscreen controller max/min register. */
75 +#define EP93XX_TOUCHSCREEN_XYMAXMIN    EP93XX_TOUCHSCREEN_REG(0x04)
76 +/* R   touchscreen controller result register. */
77 +#define EP93XX_TOUCHSCREEN_XYRESULT    EP93XX_TOUCHSCREEN_REG(0x08)
78 +/* LOCKED R/W touchscreen Switch Matrix control register. */
79 +#define EP93XX_TOUCHSCREEN_DISCHARGE   EP93XX_TOUCHSCREEN_REG(0x0C)
80 +#define EP93XX_TOUCHSCREEN_XSAMPLE     EP93XX_TOUCHSCREEN_REG(0x10)
81 +#define EP93XX_TOUCHSCREEN_YSAMPLE     EP93XX_TOUCHSCREEN_REG(0x14)
82 +#define EP93XX_TOUCHSCREEN_DIRECT      EP93XX_TOUCHSCREEN_REG(0x18)
83 +#define EP93XX_TOUCHSCREEN_DETECT      EP93XX_TOUCHSCREEN_REG(0x1C)
84 +/*  NA    R/W touchscreen software lock register. */
85 +#define EP93XX_TOUCHSCREEN_SWLOCK      EP93XX_TOUCHSCREEN_REG(0x20)
86 +/* R/W touchscreen setup control register #2. */
87 +#define EP93XX_TOUCHSCREEN_SETUP2      EP93XX_TOUCHSCREEN_REG(0x24)
88 +
89 +/* These are duplicated in mach-ep93xx/core.c */
90 +#define EP93XX_TIMER_REG(x)    (EP93XX_TIMER_BASE + (x))
91 +#define EP93XX_TIMER2_LOAD     EP93XX_TIMER_REG(0x20)
92 +#define EP93XX_TIMER2_VALUE    EP93XX_TIMER_REG(0x24)
93 +#define EP93XX_TIMER2_CONTROL  EP93XX_TIMER_REG(0x28)
94 +#define EP93XX_TIMER2_CLEAR    EP93XX_TIMER_REG(0x2c)
95 +
96 +/*
97 + * Register bit definitions
98 + */
99 +#define TSSETUP_SDLY_MASK      0x000003FF
100 +#define TSSETUP_SDLY_SHIFT     0
101 +#define TSSETUP_NSMP_4         0x00000000
102 +#define TSSETUP_NSMP_8         0x00000400
103 +#define TSSETUP_NSMP_16                0x00000800
104 +#define TSSETUP_NSMP_32                0x00000C00
105 +#define TSSETUP_NSMP_MASK      0x00000C00
106 +#define TSSETUP_DEV_4          0x00000000
107 +#define TSSETUP_DEV_8          0x00001000
108 +#define TSSETUP_DEV_12         0x00002000
109 +#define TSSETUP_DEV_16         0x00003000
110 +#define TSSETUP_DEV_24         0x00004000
111 +#define TSSETUP_DEV_32         0x00005000
112 +#define TSSETUP_DEV_64         0x00006000
113 +#define TSSETUP_DEV_128                0x00007000
114 +#define TSSETUP_ENABLE         0x00008000
115 +#define TSSETUP_DLY_MASK       0x03FF0000
116 +#define TSSETUP_DLY_SHIFT      16
117 +#define TSSETUP_TDTCT          0x80000000
118 +
119 +#define TSMAXMIN_XMIN_MASK     0x000000FF
120 +#define TSMAXMIN_XMIN_SHIFT    0
121 +#define TSMAXMIN_YMIN_MASK     0x0000FF00
122 +#define TSMAXMIN_YMIN_SHIFT    8
123 +#define TSMAXMIN_XMAX_MASK     0x00FF0000
124 +#define TSMAXMIN_XMAX_SHIFT    16
125 +#define TSMAXMIN_YMAX_MASK     0xFF000000
126 +#define TSMAXMIN_YMAX_SHIFT    24
127 +
128 +#define TSXYRESULT_X_MASK      0x00000FFF
129 +#define TSXYRESULT_X_SHIFT     0
130 +#define TSXYRESULT_AD_MASK     0x0000FFFF
131 +#define TSXYRESULT_AD_SHIFT    0
132 +#define TSXYRESULT_Y_MASK      0x0FFF0000
133 +#define TSXYRESULT_Y_SHIFT     16
134 +#define TSXYRESULT_SDR         0x80000000
135 +
136 +#define TSX_SAMPLE_MASK                0x00003FFF
137 +#define TSX_SAMPLE_SHIFT       0x00
138 +#define TSY_SAMPLE_MASK                0x3FFF0000
139 +#define TSY_SAMPLE_SHIFT       0x10
140 +
141 +#define TSSETUP2_TINT          0x00000001
142 +#define TSSETUP2_NICOR         0x00000002
143 +#define TSSETUP2_PINT          0x00000004
144 +#define TSSETUP2_PENSTS                0x00000008
145 +#define TSSETUP2_PINTEN                0x00000010
146 +#define TSSETUP2_DEVINT                0x00000020
147 +#define TSSETUP2_DINTEN                0x00000040
148 +#define TSSETUP2_DTMEN         0x00000080
149 +#define TSSETUP2_DISDEV                0x00000100
150 +#define TSSETUP2_NSIGND                0x00000200
151 +#define TSSETUP2_S28EN         0x00000400
152 +#define TSSETUP2_RINTEN                0x00000800
153 +
154 +#define TSXYRESULT_SDR         0x80000000
155 +
156 +/*
157 + * These are used as trigger levels to know when we have pen up/down.
158 + * The rules:
159 + * 1.  TS_HEAVY_INV_PRESSURE < TS_LIGHT_INV_PRESSURE because these
160 + *    are Inverse pressure.
161 + * 2.  Any touch lighter than TS_LIGHT_INV_PRESSURE is a pen up.
162 + * 3.  Any touch heavier than TS_HEAVY_INV_PRESSURE is a pen down.
163 + */
164 +#define TS_HEAVY_INV_PRESSURE 0xFE0 /* C00 */
165 +#define TS_LIGHT_INV_PRESSURE 0xFFF /* e00 */
166 +
167 +/*
168 + * If the x, y, or inverse pressure changes more than these values
169 + * between two succeeding points, the point is not reported.
170 + */
171 +#define TS_MAX_VALID_XY_CHANGE         0x300
172 +#define TS_MAX_VALID_PRESSURE_CHANGE   0x100
173 +
174 +/*
175 + * This is the minimum Z1 Value that is valid.
176 + */
177 +#define MIN_Z1_VALUE 0x50
178 +
179 +/*
180 + * Settling delay for taking each ADC measurement.  Increase this
181 + * if ts is jittery.
182 + */
183 +#define EP93XX_TS_ADC_DELAY_USEC 2000
184 +
185 +/*
186 + * Delay between TS points.
187 + */
188 +#define EP93XX_TS_PER_POINT_DELAY_USEC 10000
189 +
190 +/*
191 + * A few more macros...
192 + */
193 +#define TSSETUP_DEFAULT  (TSSETUP_NSMP_32 | TSSETUP_DEV_64 |  \
194 +                         ((128<<TSSETUP_SDLY_SHIFT) & TSSETUP_SDLY_MASK) | \
195 +                         ((128<<TSSETUP_DLY_SHIFT)  & TSSETUP_DLY_MASK))
196 +
197 +#define TSSETUP2_DEFAULT (TSSETUP2_NSIGND)
198 +
199 +/*
200 + * For now, we use one of the minor numbers from the local/experimental
201 + * range.
202 + */
203 +#define EP93XX_TS_MINOR 240
204 +
205 +/*
206 + * Static Declarations
207 + */
208 +static unsigned int   guiLastX, guiLastY;
209 +static unsigned int   guiLastInvPressure;
210 +
211 +struct TouchScreenSample
212 +{
213 +    int currentX;
214 +    int currentY;
215 +    int currentButton;
216 +    int currentPressure;
217 +    struct timeval currentTime;
218 +};
219 +
220 +/*
221 + * This must match the structure in tslib.
222 + */
223 +struct ts_sample {
224 +    int x;
225 +    int y;
226 +    unsigned int pressure;
227 +    struct timeval tv;
228 +};
229 +
230 +static struct TouchScreenSample gSample;
231 +static int bFreshTouchData;
232 +static int bCurrentPenDown;
233 +
234 +static DECLARE_WAIT_QUEUE_HEAD(queue);
235 +static DEFINE_SEMAPHORE(open_sem);
236 +static DEFINE_SPINLOCK(event_buffer_lock);
237 +static struct fasync_struct *ep93xx_fasync;
238 +
239 +/*
240 + * Typedef Declarations
241 + */
242 +typedef enum {
243 +    TS_MODE_UN_INITIALIZED,
244 +    TS_MODE_HARDWARE_SCAN,
245 +    TS_MODE_SOFT_SCAN
246 +} ts_mode_t;
247 +
248 +static ts_mode_t gScanningMode;
249 +
250 +typedef enum{
251 +    TS_STATE_STOPPED = 0,
252 +    TS_STATE_Z1,
253 +    TS_STATE_Z2,
254 +    TS_STATE_Y,
255 +    TS_STATE_X,
256 +    TS_STATE_DONE
257 +} ts_states_t;
258 +
259 +typedef struct
260 +{
261 +    unsigned int uiX;
262 +    unsigned int uiY;
263 +    unsigned int uiZ1;
264 +    unsigned int uiZ2;
265 +    ts_states_t  state;
266 +} ts_struct_t;
267 +
268 +static ts_struct_t sTouch;
269 +
270 +/*
271 + * From the spec, here's how to set up the touch screen's switch registers.
272 + */
273 +typedef struct
274 +{
275 +    unsigned int uiDetect;
276 +    unsigned int uiDischarge;
277 +    unsigned int uiXSample;
278 +    unsigned int uiYSample;
279 +    unsigned int uiSwitchZ1;
280 +    unsigned int uiSwitchZ2;
281 +}SwitchStructType;
282 +
283 +/*
284 + * Here's the switch settings for a 4-wire touchscreen.  See the spec
285 + * for how to handle a 4, 7, or 8-wire.
286 + */
287 +const static SwitchStructType sSwitchSettings =
288 +/* s28en=0 */
289 +/*   TSDetect    TSDischarge TSXSample   TSYSample   SwitchZ1    SwitchZ2 */
290 +    {0x00403604, 0x0007fe04, 0x00081604, 0x00104601, 0x00101601, 0x00101608};
291 +
292 +/*
293 + * Function declarations
294 + */
295 +static void ep93xx_ts_set_direct(unsigned int uiADCSwitch);
296 +static irqreturn_t ep93xx_ts_isr(int irq, void *dev_id);
297 +static irqreturn_t ep93xx_timer2_isr(int irq, void *dev_id);
298 +static void ee93xx_ts_evt_add(int button, int dX, int dY, int Pressure);
299 +static ssize_t ep93xx_ts_read(struct file *filp, char *buf,
300 +       size_t count, loff_t *l);
301 +static unsigned int ep93xx_ts_poll(struct file *filp, poll_table *wait);
302 +static int ep93xx_ts_open(struct inode *inode, struct file *filp);
303 +static int ep93xx_ts_fasync(int fd, struct file *filp, int on);
304 +static int ep93xx_ts_release(struct inode *inode, struct file *filp);
305 +static ssize_t ep93xx_ts_write(struct file *file, const char *buffer,
306 +               size_t count, loff_t *ppos);
307 +static void ep93xx_ts_setup(void);
308 +static void ep93xx_ts_shutdown(void);
309 +int __init ep93xx_ts_init(void);
310 +void __exit ep93xx_ts_exit(void);
311 +static unsigned int CalculateInvPressure(void);
312 +static unsigned int ADCGetData(unsigned int uiSamples, unsigned int uiMaxDiff);
313 +static void TS_Soft_Scan_Mode(void);
314 +static void TS_Hardware_Scan_Mode(void);
315 +static void ProcessPointData(void);
316 +static void Set_Timer2_uSec(unsigned int Delay_mSec);
317 +static void Stop_Timer2(void);
318 +
319 +/*
320 + *  ep93xx_ts_isr
321 + */
322 +static irqreturn_t ep93xx_ts_isr(int irq, void *dev_id)
323 +{
324 +    /*
325 +     * Note that we don't clear the interrupt here.  The interrupt
326 +     * gets cleared in TS_Soft_Scan_Mode when the TS ENABLE
327 +     * bit is cleared.
328 +     */
329 +
330 +    /*
331 +     * Set the ts to manual polling mode and schedule a callback.
332 +     * That way we can return from the isr in a reasonable amount of
333 +     * time and process the touch in the callback after a brief delay.
334 +     */
335 +    TS_Soft_Scan_Mode();
336 +
337 +    return(IRQ_HANDLED);
338 +}
339 +
340 +/*
341 + * Save the current ts 'event' in an atomic fashion.
342 + */
343 +static void ee93xx_ts_evt_add(int buttons, int iX, int iY, int iPressure)
344 +{
345 +    /*
346 +     * Note the event, but use spinlocks to keep it from getting
347 +     * halfway read if we get interrupted.
348 +     */
349 +
350 +    spin_lock(&event_buffer_lock);
351 +
352 +    gSample.currentX        = iX;
353 +    gSample.currentY        = iY;
354 +    gSample.currentButton   = buttons;
355 +    gSample.currentPressure = iPressure;
356 +    bFreshTouchData         = 1;
357 +    do_gettimeofday(&gSample.currentTime);
358 +
359 +    spin_unlock(&event_buffer_lock);
360 +
361 +    kill_fasync(&ep93xx_fasync, SIGIO, POLL_IN);
362 +    wake_up_interruptible(&queue);
363 +}
364 +
365 +
366 +static ssize_t ep93xx_ts_read(struct file *filp, char *buf, size_t count, loff_t *l)
367 +{
368 +    unsigned short data[3];
369 +    struct  ts_sample   ts_data;
370 +    int     iReturn = -EFAULT;
371 +
372 +    if (!bFreshTouchData)
373 +    {
374 +       iReturn = 0;
375 +    }
376 +    else if (count == sizeof(data))
377 +    {
378 +       spin_lock_irq(&event_buffer_lock);
379 +       bFreshTouchData = 0;
380 +       data[0] = gSample.currentX;
381 +       data[1] = gSample.currentY;
382 +       data[2] = gSample.currentButton;
383 +
384 +       spin_unlock_irq(&event_buffer_lock);
385 +
386 +       if (copy_to_user(buf, data, sizeof data))
387 +           return -EFAULT;
388 +
389 +       count -= sizeof(data);
390 +
391 +       /* return the # of bytes that got read */
392 +       iReturn = sizeof(data) ;
393 +    }
394 +    else if (count == sizeof(struct ts_sample) )
395 +    {
396 +       spin_lock_irq(&event_buffer_lock);
397 +       bFreshTouchData = 0;
398 +       ts_data.x           = gSample.currentX;
399 +       ts_data.y           = gSample.currentY;
400 +       ts_data.pressure    = gSample.currentPressure;
401 +       ts_data.tv          = gSample.currentTime;
402 +       spin_unlock_irq(&event_buffer_lock);
403 +
404 +       if (copy_to_user(buf, &ts_data, sizeof(struct ts_sample)))
405 +       {
406 +           iReturn = -EFAULT;
407 +       }
408 +       else
409 +       {
410 +           count -= sizeof(ts_data);
411 +           iReturn = sizeof(ts_data);
412 +       }
413 +    }
414 +
415 +    return iReturn;
416 +}
417 +
418 +static unsigned int ep93xx_ts_poll(struct file *filp, poll_table *wait)
419 +{
420 +    poll_wait(filp, &queue, wait);
421 +
422 +    if (bFreshTouchData)
423 +    {
424 +       return POLLIN | POLLRDNORM;
425 +    }
426 +
427 +    return 0;
428 +}
429 +
430 +static int ep93xx_ts_open(struct inode *inode, struct file *filp)
431 +{
432 +    if (down_trylock(&open_sem))
433 +    {
434 +       return -EBUSY;
435 +    }
436 +
437 +    ep93xx_ts_setup();
438 +
439 +    return 0;
440 +}
441 +
442 +/*
443 + * Asynchronous I/O support.
444 + */
445 +static int ep93xx_ts_fasync(int fd, struct file *filp, int on)
446 +{
447 +    int retval;
448 +
449 +    retval = fasync_helper(fd, filp, on, &ep93xx_fasync);
450 +    if (retval < 0)
451 +    {
452 +       return retval;
453 +    }
454 +
455 +    return 0;
456 +}
457 +
458 +static int ep93xx_ts_release(struct inode *inode, struct file *filp)
459 +{
460 +    Stop_Timer2();
461 +
462 +    /*
463 +     * Call our async I/O support to request that this file
464 +     * cease to be used for async I/O.
465 +     */
466 +    ep93xx_ts_fasync(-1, filp, 0);
467 +
468 +    ep93xx_ts_shutdown();
469 +
470 +    up(&open_sem);
471 +
472 +    return 0;
473 +}
474 +
475 +static ssize_t ep93xx_ts_write(struct file *file, const char *buffer, size_t count,
476 +              loff_t *ppos)
477 +{
478 +    return -EINVAL;
479 +}
480 +
481 +
482 +static int ep93xx_ts_ioctl(struct inode *inode, struct file *file, uint command, ulong u)
483 +{
484 +    static const int         version = EV_VERSION;
485 +    static const u_int32_t   bit =(1 << EV_ABS);
486 +    static const u_int32_t   absbit = (1 << ABS_X) | (1 << ABS_Y) | (1 << ABS_PRESSURE);
487 +    int         iReturn ;
488 +    int         i = 0;
489 +
490 +    switch(command)
491 +    {
492 +       case EVIOCGVERSION:
493 +           i = copy_to_user((void __user *)u, (void *)version, sizeof(version));
494 +           iReturn = i ? -EFAULT : 0;
495 +           break;
496 +
497 +       case EVIOCGBIT(0,sizeof(u_int32_t) * 8) :
498 +           i = copy_to_user((void __user *)u, (void *)bit, sizeof(bit));
499 +           iReturn = i ? -EFAULT : 0;
500 +           break;
501 +
502 +       case EVIOCGBIT(EV_ABS, sizeof(absbit) * 8):
503 +           i = copy_to_user((void __user *)u, (void *)absbit, sizeof(absbit));
504 +           iReturn = i ? -EFAULT : 0;
505 +           break;
506 +       default:
507 +           iReturn = -1;
508 +           break;
509 +    }
510 +
511 +    return iReturn;
512 +}
513 +
514 +static struct file_operations ep93xx_ts_fops = {
515 +    owner:      THIS_MODULE,
516 +    read:       ep93xx_ts_read,
517 +    write:      ep93xx_ts_write,
518 +    poll:       ep93xx_ts_poll,
519 +    open:       ep93xx_ts_open,
520 +    unlocked_ioctl:      ep93xx_ts_ioctl,
521 +    release:    ep93xx_ts_release,
522 +    fasync:     ep93xx_ts_fasync,
523 +};
524 +
525 +static struct miscdevice ep93xx_ts_miscdev =
526 +{
527 +       EP93XX_TS_MINOR,
528 +       "ep93xx_ts",
529 +       &ep93xx_ts_fops
530 +};
531 +
532 +void ep93xx_ts_setup(void)
533 +{
534 +    unsigned int uiKTDIV, uiTSXYMaxMin;
535 +
536 +    /*
537 +     * Set the TSEN bit in KTDIV so that we are enabling the clock
538 +     * for the touchscreen.
539 +     */
540 +    uiKTDIV = __raw_readl(EP93XX_SYSCON_KEYTCHCLKDIV);
541 +    uiKTDIV |= EP93XX_SYSCON_KEYTCHCLKDIV_TSEN;
542 +    ep93xx_syscon_swlocked_write(uiKTDIV, EP93XX_SYSCON_KEYTCHCLKDIV);
543 +
544 +    /*
545 +     * Program the EP93XX_TOUCHSCREEN_SETUP and TSSetup2 registers.
546 +     */
547 +    __raw_writel(TSSETUP_DEFAULT, EP93XX_TOUCHSCREEN_SETUP);
548 +    __raw_writel(TSSETUP2_DEFAULT, EP93XX_TOUCHSCREEN_SETUP2);
549 +
550 +    /*
551 +     * Set the the touch settings.
552 +     */
553 +    __raw_writel(0xaa, EP93XX_TOUCHSCREEN_SWLOCK);
554 +    __raw_writel(sSwitchSettings.uiDischarge, EP93XX_TOUCHSCREEN_DIRECT);
555 +
556 +    __raw_writel(0xaa, EP93XX_TOUCHSCREEN_SWLOCK);
557 +    __raw_writel(sSwitchSettings.uiDischarge, EP93XX_TOUCHSCREEN_DISCHARGE);
558 +
559 +    __raw_writel(0xaa, EP93XX_TOUCHSCREEN_SWLOCK);
560 +    __raw_writel(sSwitchSettings.uiSwitchZ1, EP93XX_TOUCHSCREEN_XSAMPLE);
561 +
562 +    __raw_writel(0xaa, EP93XX_TOUCHSCREEN_SWLOCK);
563 +    __raw_writel(sSwitchSettings.uiSwitchZ2, EP93XX_TOUCHSCREEN_YSAMPLE);
564 +
565 +    __raw_writel(0xaa, EP93XX_TOUCHSCREEN_SWLOCK);
566 +    __raw_writel(sSwitchSettings.uiDetect, EP93XX_TOUCHSCREEN_DETECT);
567 +
568 +    /*
569 +     * X,YMin set to 0x40 = have to drag that many pixels for a new irq.
570 +     * X,YMax set to 0x40 = 1024 pixels is the maximum movement within the
571 +     * time scan limit.
572 +     */
573 +    uiTSXYMaxMin =  (50   << TSMAXMIN_XMIN_SHIFT) & TSMAXMIN_XMIN_MASK;
574 +    uiTSXYMaxMin |= (50   << TSMAXMIN_YMIN_SHIFT) & TSMAXMIN_YMIN_MASK;
575 +    uiTSXYMaxMin |= (0xff << TSMAXMIN_XMAX_SHIFT) & TSMAXMIN_XMAX_MASK;
576 +    uiTSXYMaxMin |= (0xff << TSMAXMIN_YMAX_SHIFT) & TSMAXMIN_YMAX_MASK;
577 +    __raw_writel(uiTSXYMaxMin, EP93XX_TOUCHSCREEN_XYMAXMIN);
578 +
579 +    bCurrentPenDown = 0;
580 +    bFreshTouchData = 0;
581 +    guiLastX = 0;
582 +    guiLastY = 0;
583 +    guiLastInvPressure = 0xffffff;
584 +
585 +    /*
586 +     * Enable the touch screen scanning engine.
587 +     */
588 +    TS_Hardware_Scan_Mode();
589 +}
590 +
591 +/*
592 + * ep93xx_ts_shutdown
593 + *
594 + */
595 +static void
596 +ep93xx_ts_shutdown(void)
597 +{
598 +    unsigned int uiKTDIV;
599 +
600 +    sTouch.state = TS_STATE_STOPPED;
601 +    Stop_Timer2();
602 +
603 +    /*
604 +     * Disable the scanning engine.
605 +     */
606 +    __raw_writel(0, EP93XX_TOUCHSCREEN_SETUP);
607 +    __raw_writel(0, EP93XX_TOUCHSCREEN_SETUP2);
608 +
609 +    /*
610 +     * Clear the TSEN bit in KTDIV so that we are disabling the clock
611 +     * for the touchscreen.
612 +     */
613 +    uiKTDIV = __raw_readl(EP93XX_SYSCON_KEYTCHCLKDIV);
614 +    uiKTDIV &= ~EP93XX_SYSCON_KEYTCHCLKDIV_TSEN;
615 +    ep93xx_syscon_swlocked_write(uiKTDIV, EP93XX_SYSCON_KEYTCHCLKDIV);
616 +
617 +} /* ep93xx_ts_shutdown */
618 +
619 +static irqreturn_t ep93xx_timer2_isr(int irq, void *dev_id)
620 +{
621 +    switch(sTouch.state)
622 +    {
623 +       case TS_STATE_STOPPED:
624 +           TS_Hardware_Scan_Mode();
625 +           break;
626 +
627 +       /*
628 +        * Get the Z1 value for pressure measurement and set up
629 +        * the switch register for getting the Z2 measurement.
630 +        */
631 +       case TS_STATE_Z1:
632 +           Set_Timer2_uSec(EP93XX_TS_ADC_DELAY_USEC);
633 +           sTouch.uiZ1 = ADCGetData(2, 200);
634 +           ep93xx_ts_set_direct(sSwitchSettings.uiSwitchZ2);
635 +           sTouch.state = TS_STATE_Z2;
636 +           break;
637 +
638 +       /*
639 +        * Get the Z2 value for pressure measurement and set up
640 +        * the switch register for getting the Y measurement.
641 +        */
642 +       case TS_STATE_Z2:
643 +           sTouch.uiZ2 = ADCGetData(2, 200);
644 +           ep93xx_ts_set_direct(sSwitchSettings.uiYSample);
645 +           sTouch.state = TS_STATE_Y;
646 +           break;
647 +
648 +       /*
649 +        * Get the Y value and set up the switch register for
650 +        * getting the X measurement.
651 +        */
652 +       case TS_STATE_Y:
653 +           sTouch.uiY = ADCGetData(4, 20);
654 +           ep93xx_ts_set_direct(sSwitchSettings.uiXSample);
655 +           sTouch.state = TS_STATE_X;
656 +           break;
657 +
658 +       /*
659 +        * Read the X value.  This is the last of the 4 adc values
660 +        * we need so we continue on to process the data.
661 +        */
662 +       case TS_STATE_X:
663 +           Stop_Timer2();
664 +
665 +           sTouch.uiX = ADCGetData(4, 20);
666 +
667 +           __raw_writel(0xaa, EP93XX_TOUCHSCREEN_SWLOCK);
668 +           __raw_writel(sSwitchSettings.uiDischarge, EP93XX_TOUCHSCREEN_DIRECT);
669 +
670 +           sTouch.state = TS_STATE_DONE;
671 +
672 +           /*
673 +            * Process this set of ADC readings.
674 +            */
675 +           ProcessPointData();
676 +
677 +           break;
678 +
679 +       /*
680 +        * Shouldn't get here.  But if we do, we can recover...
681 +        */
682 +       case TS_STATE_DONE:
683 +           TS_Hardware_Scan_Mode();
684 +           break;
685 +    }
686 +
687 +    /*
688 +     * Clear the timer2 interrupt.
689 +     */
690 +    __raw_writel(1, EP93XX_TIMER2_CLEAR);
691 +    return(IRQ_HANDLED);
692 +}
693 +
694 +/*---------------------------------------------------------------------
695 + * ProcessPointData
696 + *
697 + * This routine processes the ADC data into usable point data and then
698 + * puts the driver into hw or sw scanning mode before returning.
699 + *
700 + * We calculate inverse pressure (lower number = more pressure) then
701 + * do a hystheresis with the two pressure values 'light' and 'heavy'.
702 + *
703 + * If we are above the light, we have pen up.
704 + * If we are below the heavy we have pen down.
705 + * As long as the pressure stays below the light, pen stays down.
706 + * When we get above the light again, pen goes back up.
707 + *
708 + */
709 +static void ProcessPointData(void)
710 +{
711 +    int  bValidPoint = 0;
712 +    unsigned int   uiXDiff, uiYDiff, uiInvPressureDiff;
713 +    unsigned int   uiInvPressure;
714 +
715 +    /*
716 +     * Calculate the current pressure.
717 +     */
718 +    uiInvPressure = CalculateInvPressure();
719 +
720 +    /*
721 +     * If pen pressure is so light that it is greater than the 'max' setting
722 +     * then we consider this to be a pen up.
723 +     */
724 +    if (uiInvPressure >= TS_LIGHT_INV_PRESSURE)
725 +    {
726 +       bCurrentPenDown = 0;
727 +       ee93xx_ts_evt_add(0, guiLastX, guiLastY, 0);
728 +       TS_Hardware_Scan_Mode();
729 +       return;
730 +    }
731 +
732 +    /*
733 +     * Hysteresis:
734 +     * If the pen pressure is hard enough to be less than the 'min' OR
735 +     * the pen is already down and is still less than the 'max'...
736 +     */
737 +    if ((uiInvPressure < TS_HEAVY_INV_PRESSURE) ||
738 +       (bCurrentPenDown && (uiInvPressure < TS_LIGHT_INV_PRESSURE)))
739 +    {
740 +       if (bCurrentPenDown)
741 +       {
742 +           /*
743 +            * If pen was previously down, check the difference between
744 +            * the last sample and this one... if the difference between
745 +            * samples is too great, ignore the sample.
746 +            */
747 +           uiXDiff = abs(guiLastX - sTouch.uiX);
748 +           uiYDiff = abs(guiLastY - sTouch.uiY);
749 +           uiInvPressureDiff = abs(guiLastInvPressure - uiInvPressure);
750 +
751 +           if (uiXDiff < TS_MAX_VALID_XY_CHANGE
752 +               && uiYDiff < TS_MAX_VALID_XY_CHANGE
753 +               && uiInvPressureDiff < TS_MAX_VALID_PRESSURE_CHANGE)
754 +           {
755 +               bValidPoint = 1;
756 +           }
757 +       }
758 +       else
759 +       {
760 +           bValidPoint = 1;
761 +       }
762 +
763 +       /*
764 +        * If either the pen was put down or dragged make a note of it.
765 +        */
766 +       if (bValidPoint)
767 +       {
768 +           guiLastX = sTouch.uiX;
769 +           guiLastY = sTouch.uiY;
770 +           guiLastInvPressure = uiInvPressure;
771 +           bCurrentPenDown = 1;
772 +           ee93xx_ts_evt_add(1, sTouch.uiX, sTouch.uiY,
773 +                             0x7000000 / uiInvPressure);
774 +       }
775 +
776 +       TS_Soft_Scan_Mode();
777 +       return;
778 +    }
779 +
780 +    TS_Hardware_Scan_Mode();
781 +}
782 +
783 +static void ep93xx_ts_set_direct(unsigned int uiADCSwitch)
784 +{
785 +    unsigned int uiResult;
786 +
787 +    /*
788 +     * Set the switch settings in the direct register.
789 +     */
790 +    __raw_writel(0xaa, EP93XX_TOUCHSCREEN_SWLOCK);
791 +    __raw_writel(uiADCSwitch, EP93XX_TOUCHSCREEN_DIRECT);
792 +
793 +    /*
794 +     * Read and throw away the first sample.
795 +     */
796 +    do {
797 +       uiResult = __raw_readl(EP93XX_TOUCHSCREEN_XYRESULT);
798 +    } while (!(uiResult & TSXYRESULT_SDR));
799 +
800 +}
801 +
802 +static unsigned int ADCGetData(unsigned int uiSamples, unsigned int uiMaxDiff)
803 +{
804 +    unsigned int uiResult, uiValue, uiCount, uiLowest, uiHighest, uiSum, uiAve;
805 +
806 +    do
807 +    {
808 +       /*
809 +        * Initialize our values.
810 +        */
811 +       uiLowest        = 0xfffffff;
812 +       uiHighest       = 0;
813 +       uiSum           = 0;
814 +
815 +       for (uiCount = 0; uiCount < uiSamples; uiCount++)
816 +       {
817 +           /*
818 +            * Read the touch screen four more times and average.
819 +            */
820 +           do {
821 +               uiResult = __raw_readl(EP93XX_TOUCHSCREEN_XYRESULT);
822 +           } while (!(uiResult & TSXYRESULT_SDR));
823 +
824 +           uiValue = (uiResult & TSXYRESULT_AD_MASK) >> TSXYRESULT_AD_SHIFT;
825 +           uiValue = ((uiValue >> 4) + ((1 + TSXYRESULT_X_MASK)>>1)) & TSXYRESULT_X_MASK;
826 +
827 +           /*
828 +            * Add up the values.
829 +            */
830 +           uiSum += uiValue;
831 +
832 +           /*
833 +            * Get the lowest and highest values.
834 +            */
835 +           if (uiValue < uiLowest)
836 +           {
837 +               uiLowest = uiValue;
838 +           }
839 +           if (uiValue > uiHighest)
840 +           {
841 +               uiHighest = uiValue;
842 +           }
843 +       }
844 +    } while ((uiHighest - uiLowest) > uiMaxDiff);
845 +
846 +    /*
847 +     * Calculate the Average value.
848 +     */
849 +    uiAve = uiSum / uiSamples;
850 +
851 +    return uiAve;
852 +}
853 +
854 +/*
855 + * CalculateInvPressure
856 + *
857 + * Is the Touch Valid.  Touch is not valid if the X or Y value is not
858 + * in range and the pressure is not  enough.
859 + *
860 + * Touch resistance can be measured by the following formula:
861 + *
862 + *          Rx * X *     Z2
863 + * Rtouch = --------- * (-- - 1)
864 + *           4096        Z1
865 + *
866 + * This is simplified in the ration of Rtouch to Rx.  The lower the value, the
867 + * higher the pressure.
868 + *
869 + *                     Z2
870 + * InvPressure =  X * (-- - 1)
871 + *                     Z1
872 + */
873 +static unsigned int CalculateInvPressure(void)
874 +{
875 +    unsigned int uiInvPressure;
876 +
877 +    /*
878 +     * Check to see if the point is valid.
879 +     */
880 +    if (sTouch.uiZ1 < MIN_Z1_VALUE)
881 +    {
882 +       uiInvPressure = 0x10000;
883 +    }
884 +
885 +    /*
886 +     * Can omit the pressure calculation if you need to get rid of the division.
887 +     */
888 +    else
889 +    {
890 +       uiInvPressure = ((sTouch.uiX * sTouch.uiZ2) / sTouch.uiZ1) - sTouch.uiX;
891 +    }
892 +
893 +    return uiInvPressure;
894 +}
895 +
896 +/*
897 + * TS_Hardware_Scan_Mode
898 + *
899 + * Enables the ep93xx ts scanning engine so that when the pen goes down
900 + * we will get an interrupt.
901 + */
902 +static void TS_Hardware_Scan_Mode(void)
903 +{
904 +    unsigned int uiDevCfg;
905 +
906 +    /*
907 +     * Disable the soft scanning engine.
908 +     */
909 +    sTouch.state = TS_STATE_STOPPED;
910 +    Stop_Timer2();
911 +
912 +    /*
913 +     * Clear the TIN (Touchscreen INactive) bit so we can go to
914 +     * automatic scanning mode.
915 +     */
916 +    uiDevCfg = __raw_readl(EP93XX_SYSCON_DEVCFG);
917 +    ep93xx_syscon_swlocked_write(uiDevCfg & ~EP93XX_SYSCON_DEVCFG_TIN,
918 +                                EP93XX_SYSCON_DEVCFG);
919 +
920 +    /*
921 +     * Enable the touch screen scanning state machine by setting
922 +     * the ENABLE bit.
923 +     */
924 +    __raw_writel(TSSETUP_DEFAULT | TSSETUP_ENABLE, EP93XX_TOUCHSCREEN_SETUP);
925 +
926 +    /*
927 +     * Set the flag to show that we are in interrupt mode.
928 +     */
929 +    gScanningMode = TS_MODE_HARDWARE_SCAN;
930 +
931 +    /*
932 +     * Initialize EP93XX_TOUCHSCREEN_SETUP2 register.
933 +     */
934 +    __raw_writel(TSSETUP2_DEFAULT, EP93XX_TOUCHSCREEN_SETUP2);
935 +
936 +}
937 +
938 +/*
939 + * TS_Soft_Scan_Mode
940 + *
941 + * Sets the touch screen to manual polling mode.
942 + */
943 +static void TS_Soft_Scan_Mode(void)
944 +{
945 +    unsigned int uiDevCfg;
946 +
947 +    if (gScanningMode != TS_MODE_SOFT_SCAN)
948 +    {
949 +       /*
950 +        * Disable the touch screen scanning state machine by clearing
951 +        * the ENABLE bit.
952 +        */
953 +       __raw_writel(TSSETUP_DEFAULT, EP93XX_TOUCHSCREEN_SETUP);
954 +
955 +       /*
956 +        * Set the TIN bit so we can do manual touchscreen polling.
957 +        */
958 +       uiDevCfg = __raw_readl(EP93XX_SYSCON_DEVCFG);
959 +       ep93xx_syscon_swlocked_write(uiDevCfg | EP93XX_SYSCON_DEVCFG_TIN,
960 +                                    EP93XX_SYSCON_DEVCFG);
961 +    }
962 +
963 +    /*
964 +     * Set the switch register up for the first ADC reading
965 +     */
966 +    ep93xx_ts_set_direct(sSwitchSettings.uiSwitchZ1);
967 +
968 +    /*
969 +     * Initialize our software state machine to know which ADC
970 +     * reading to take
971 +     */
972 +    sTouch.state = TS_STATE_Z1;
973 +
974 +    /*
975 +     * Set the timer so after a mSec or two settling delay it will
976 +     * take the first ADC reading.
977 +     */
978 +    Set_Timer2_uSec(EP93XX_TS_PER_POINT_DELAY_USEC);
979 +
980 +    /*
981 +     * Note that we are in sw scanning mode not hw scanning mode.
982 +     */
983 +    gScanningMode = TS_MODE_SOFT_SCAN;
984 +
985 +}
986 +
987 +static void Set_Timer2_uSec(unsigned int uiDelay_uSec)
988 +{
989 +    unsigned int uiClockTicks;
990 +
991 +    /*
992 +     * Stop timer 2
993 +     */
994 +    __raw_writel(0, EP93XX_TIMER2_CONTROL);
995 +
996 +    uiClockTicks = ((uiDelay_uSec * 508) + 999) / 1000;
997 +    __raw_writel(uiClockTicks, EP93XX_TIMER2_LOAD);
998 +    __raw_writel(uiClockTicks, EP93XX_TIMER2_VALUE);
999 +
1000 +    /*
1001 +     * Set up Timer 2 for 508 kHz clock and periodic mode.
1002 +     */
1003 +    __raw_writel(0xC8, EP93XX_TIMER2_CONTROL);
1004 +
1005 +}
1006 +
1007 +static void Stop_Timer2(void)
1008 +{
1009 +    __raw_writel(0, EP93XX_TIMER2_CONTROL);
1010 +}
1011 +
1012 +/*
1013 + * Initialization and exit routines
1014 + */
1015 +int __init ep93xx_ts_init(void)
1016 +{
1017 +    int retval;
1018 +
1019 +    retval = request_irq(IRQ_EP93XX_TOUCH, ep93xx_ts_isr,
1020 +                        IRQF_DISABLED, "ep93xx_ts", 0);
1021 +    if (retval)
1022 +    {
1023 +       printk(KERN_WARNING "ep93xx_ts: failed to get touchscreen IRQ\n");
1024 +       return retval;
1025 +    }
1026 +
1027 +    retval = request_irq(IRQ_EP93XX_TIMER2, ep93xx_timer2_isr,
1028 +                        IRQF_DISABLED, "ep93xx_timer2", 0);
1029 +    if (retval)
1030 +    {
1031 +       printk(KERN_WARNING "ep93xx_ts: failed to get timer2 IRQ\n");
1032 +       free_irq(IRQ_EP93XX_TOUCH, 0);
1033 +       return retval;
1034 +    }
1035 +
1036 +    misc_register(&ep93xx_ts_miscdev);
1037 +
1038 +    sTouch.state = TS_STATE_STOPPED;
1039 +    gScanningMode = TS_MODE_UN_INITIALIZED;
1040 +
1041 +    printk(KERN_NOTICE "ep93xx touchscreen driver configured for 4-wire operation\n");
1042 +
1043 +    return 0;
1044 +}
1045 +
1046 +void __exit ep93xx_ts_exit(void)
1047 +{
1048 +    Stop_Timer2();
1049 +
1050 +    free_irq(IRQ_EP93XX_TOUCH, 0);
1051 +    free_irq(IRQ_EP93XX_TIMER2, 0);
1052 +
1053 +    misc_deregister(&ep93xx_ts_miscdev);
1054 +}
1055 +
1056 +module_init(ep93xx_ts_init);
1057 +module_exit(ep93xx_ts_exit);
1058 +
1059 +MODULE_DESCRIPTION("Cirrus EP93xx touchscreen driver");
1060 +MODULE_SUPPORTED_DEVICE("touchscreen/ep93xx");
1061 +MODULE_LICENSE("GPL");