ba648750a8d927db4a4cade7e2df61cca5348059
[linux-2.6.git] / drivers / input / touchscreen / mainstone-wm97xx.c
1 /*
2  * mainstone-wm97xx.c  --  Mainstone Continuous Touch screen driver for
3  *                         Wolfson WM97xx AC97 Codecs.
4  *
5  * Copyright 2004, 2007 Wolfson Microelectronics PLC.
6  * Author: Liam Girdwood <lrg@slimlogic.co.uk>
7  * Parts Copyright : Ian Molton <spyro@f2s.com>
8  *                   Andrew Zabolotny <zap@homelink.ru>
9  *
10  *  This program is free software; you can redistribute  it and/or modify it
11  *  under  the terms of  the GNU General  Public License as published by the
12  *  Free Software Foundation;  either version 2 of the  License, or (at your
13  *  option) any later version.
14  *
15  * Notes:
16  *     This is a wm97xx extended touch driver to capture touch
17  *     data in a continuous manner on the Intel XScale archictecture
18  *
19  *  Features:
20  *       - codecs supported:- WM9705, WM9712, WM9713
21  *       - processors supported:- Intel XScale PXA25x, PXA26x, PXA27x
22  *
23  */
24
25 #include <linux/module.h>
26 #include <linux/moduleparam.h>
27 #include <linux/kernel.h>
28 #include <linux/init.h>
29 #include <linux/delay.h>
30 #include <linux/irq.h>
31 #include <linux/interrupt.h>
32 #include <linux/wm97xx.h>
33 #include <linux/io.h>
34 #include <mach/pxa-regs.h>
35
36 #define VERSION         "0.13"
37
38 struct continuous {
39         u16 id;    /* codec id */
40         u8 code;   /* continuous code */
41         u8 reads;  /* number of coord reads per read cycle */
42         u32 speed; /* number of coords per second */
43 };
44
45 #define WM_READS(sp) ((sp / HZ) + 1)
46
47 static const struct continuous cinfo[] = {
48         {WM9705_ID2, 0, WM_READS(94), 94},
49         {WM9705_ID2, 1, WM_READS(188), 188},
50         {WM9705_ID2, 2, WM_READS(375), 375},
51         {WM9705_ID2, 3, WM_READS(750), 750},
52         {WM9712_ID2, 0, WM_READS(94), 94},
53         {WM9712_ID2, 1, WM_READS(188), 188},
54         {WM9712_ID2, 2, WM_READS(375), 375},
55         {WM9712_ID2, 3, WM_READS(750), 750},
56         {WM9713_ID2, 0, WM_READS(94), 94},
57         {WM9713_ID2, 1, WM_READS(120), 120},
58         {WM9713_ID2, 2, WM_READS(154), 154},
59         {WM9713_ID2, 3, WM_READS(188), 188},
60 };
61
62 /* continuous speed index */
63 static int sp_idx;
64 static u16 last, tries;
65
66 /*
67  * Pen sampling frequency (Hz) in continuous mode.
68  */
69 static int cont_rate = 200;
70 module_param(cont_rate, int, 0);
71 MODULE_PARM_DESC(cont_rate, "Sampling rate in continuous mode (Hz)");
72
73 /*
74  * Pen down detection.
75  *
76  * This driver can either poll or use an interrupt to indicate a pen down
77  * event. If the irq request fails then it will fall back to polling mode.
78  */
79 static int pen_int;
80 module_param(pen_int, int, 0);
81 MODULE_PARM_DESC(pen_int, "Pen down detection (1 = interrupt, 0 = polling)");
82
83 /*
84  * Pressure readback.
85  *
86  * Set to 1 to read back pen down pressure
87  */
88 static int pressure;
89 module_param(pressure, int, 0);
90 MODULE_PARM_DESC(pressure, "Pressure readback (1 = pressure, 0 = no pressure)");
91
92 /*
93  * AC97 touch data slot.
94  *
95  * Touch screen readback data ac97 slot
96  */
97 static int ac97_touch_slot = 5;
98 module_param(ac97_touch_slot, int, 0);
99 MODULE_PARM_DESC(ac97_touch_slot, "Touch screen data slot AC97 number");
100
101
102 /* flush AC97 slot 5 FIFO on pxa machines */
103 #ifdef CONFIG_PXA27x
104 static void wm97xx_acc_pen_up(struct wm97xx *wm)
105 {
106         schedule_timeout_uninterruptible(1);
107
108         while (MISR & (1 << 2))
109                 MODR;
110 }
111 #else
112 static void wm97xx_acc_pen_up(struct wm97xx *wm)
113 {
114         int count = 16;
115         schedule_timeout_uninterruptible(1);
116
117         while (count < 16) {
118                 MODR;
119                 count--;
120         }
121 }
122 #endif
123
124 static int wm97xx_acc_pen_down(struct wm97xx *wm)
125 {
126         u16 x, y, p = 0x100 | WM97XX_ADCSEL_PRES;
127         int reads = 0;
128
129         /* When the AC97 queue has been drained we need to allow time
130          * to buffer up samples otherwise we end up spinning polling
131          * for samples.  The controller can't have a suitably low
132          * threashold set to use the notifications it gives.
133          */
134         schedule_timeout_uninterruptible(1);
135
136         if (tries > 5) {
137                 tries = 0;
138                 return RC_PENUP;
139         }
140
141         x = MODR;
142         if (x == last) {
143                 tries++;
144                 return RC_AGAIN;
145         }
146         last = x;
147         do {
148                 if (reads)
149                         x = MODR;
150                 y = MODR;
151                 if (pressure)
152                         p = MODR;
153
154                 /* are samples valid */
155                 if ((x & WM97XX_ADCSRC_MASK) != WM97XX_ADCSEL_X ||
156                     (y & WM97XX_ADCSRC_MASK) != WM97XX_ADCSEL_Y ||
157                     (p & WM97XX_ADCSRC_MASK) != WM97XX_ADCSEL_PRES)
158                         goto up;
159
160                 /* coordinate is good */
161                 tries = 0;
162                 input_report_abs(wm->input_dev, ABS_X, x & 0xfff);
163                 input_report_abs(wm->input_dev, ABS_Y, y & 0xfff);
164                 input_report_abs(wm->input_dev, ABS_PRESSURE, p & 0xfff);
165                 input_sync(wm->input_dev);
166                 reads++;
167         } while (reads < cinfo[sp_idx].reads);
168 up:
169         return RC_PENDOWN | RC_AGAIN;
170 }
171
172 static int wm97xx_acc_startup(struct wm97xx *wm)
173 {
174         int idx = 0;
175
176         /* check we have a codec */
177         if (wm->ac97 == NULL)
178                 return -ENODEV;
179
180         /* Go you big red fire engine */
181         for (idx = 0; idx < ARRAY_SIZE(cinfo); idx++) {
182                 if (wm->id != cinfo[idx].id)
183                         continue;
184                 sp_idx = idx;
185                 if (cont_rate <= cinfo[idx].speed)
186                         break;
187         }
188         wm->acc_rate = cinfo[sp_idx].code;
189         wm->acc_slot = ac97_touch_slot;
190         dev_info(wm->dev,
191                  "mainstone accelerated touchscreen driver, %d samples/sec\n",
192                  cinfo[sp_idx].speed);
193
194         /* codec specific irq config */
195         if (pen_int) {
196                 switch (wm->id) {
197                 case WM9705_ID2:
198                         wm->pen_irq = IRQ_GPIO(4);
199                         set_irq_type(IRQ_GPIO(4), IRQ_TYPE_EDGE_BOTH);
200                         break;
201                 case WM9712_ID2:
202                 case WM9713_ID2:
203                         /* enable pen down interrupt */
204                         /* use PEN_DOWN GPIO 13 to assert IRQ on GPIO line 2 */
205                         wm->pen_irq = MAINSTONE_AC97_IRQ;
206                         wm97xx_config_gpio(wm, WM97XX_GPIO_13, WM97XX_GPIO_IN,
207                                            WM97XX_GPIO_POL_HIGH,
208                                            WM97XX_GPIO_STICKY,
209                                            WM97XX_GPIO_WAKE);
210                         wm97xx_config_gpio(wm, WM97XX_GPIO_2, WM97XX_GPIO_OUT,
211                                            WM97XX_GPIO_POL_HIGH,
212                                            WM97XX_GPIO_NOTSTICKY,
213                                            WM97XX_GPIO_NOWAKE);
214                         break;
215                 default:
216                         dev_err(wm->dev,
217                                 "pen down irq not supported on this device\n");
218                         pen_int = 0;
219                         break;
220                 }
221         }
222
223         return 0;
224 }
225
226 static void wm97xx_acc_shutdown(struct wm97xx *wm)
227 {
228         /* codec specific deconfig */
229         if (pen_int) {
230                 switch (wm->id & 0xffff) {
231                 case WM9705_ID2:
232                         wm->pen_irq = 0;
233                         break;
234                 case WM9712_ID2:
235                 case WM9713_ID2:
236                         /* disable interrupt */
237                         wm->pen_irq = 0;
238                         break;
239                 }
240         }
241 }
242
243 static void wm97xx_irq_enable(struct wm97xx *wm, int enable)
244 {
245         if (enable)
246                 enable_irq(wm->pen_irq);
247         else
248                 disable_irq(wm->pen_irq);
249 }
250
251 static struct wm97xx_mach_ops mainstone_mach_ops = {
252         .acc_enabled = 1,
253         .acc_pen_up = wm97xx_acc_pen_up,
254         .acc_pen_down = wm97xx_acc_pen_down,
255         .acc_startup = wm97xx_acc_startup,
256         .acc_shutdown = wm97xx_acc_shutdown,
257         .irq_enable = wm97xx_irq_enable,
258         .irq_gpio = WM97XX_GPIO_2,
259 };
260
261 static int mainstone_wm97xx_probe(struct platform_device *pdev)
262 {
263         struct wm97xx *wm = platform_get_drvdata(pdev);
264
265         return wm97xx_register_mach_ops(wm, &mainstone_mach_ops);
266 }
267
268 static int mainstone_wm97xx_remove(struct platform_device *pdev)
269 {
270         struct wm97xx *wm = platform_get_drvdata(pdev);
271
272         wm97xx_unregister_mach_ops(wm);
273         return 0;
274 }
275
276 static struct platform_driver mainstone_wm97xx_driver = {
277         .probe = mainstone_wm97xx_probe,
278         .remove = mainstone_wm97xx_remove,
279         .driver = {
280                 .name = "wm97xx-touch",
281         },
282 };
283
284 static int __init mainstone_wm97xx_init(void)
285 {
286         return platform_driver_register(&mainstone_wm97xx_driver);
287 }
288
289 static void __exit mainstone_wm97xx_exit(void)
290 {
291         platform_driver_unregister(&mainstone_wm97xx_driver);
292 }
293
294 module_init(mainstone_wm97xx_init);
295 module_exit(mainstone_wm97xx_exit);
296
297 /* Module information */
298 MODULE_AUTHOR("Liam Girdwood <lrg@slimlogic.co.uk>");
299 MODULE_DESCRIPTION("wm97xx continuous touch driver for mainstone");
300 MODULE_LICENSE("GPL");