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