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 architecture
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 <linux/gpio.h>
35
36 #include <mach/regs-ac97.h>
37
38 #include <asm/mach-types.h>
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 static int irq;
68
69 /*
70 * Pen sampling frequency (Hz) in continuous mode.
71 */
72 static int cont_rate = 200;
73 module_param(cont_rate, int, 0);
74 MODULE_PARM_DESC(cont_rate, "Sampling rate in continuous mode (Hz)");
75
76 /*
77 * Pen down detection.
78 *
79 * This driver can either poll or use an interrupt to indicate a pen down
80 * event. If the irq request fails then it will fall back to polling mode.
81 */
82 static int pen_int;
83 module_param(pen_int, int, 0);
84 MODULE_PARM_DESC(pen_int, "Pen down detection (1 = interrupt, 0 = polling)");
85
86 /*
87 * Pressure readback.
88 *
89 * Set to 1 to read back pen down pressure
90 */
91 static int pressure;
92 module_param(pressure, int, 0);
93 MODULE_PARM_DESC(pressure, "Pressure readback (1 = pressure, 0 = no pressure)");
94
95 /*
96 * AC97 touch data slot.
97 *
98 * Touch screen readback data ac97 slot
99 */
100 static int ac97_touch_slot = 5;
101 module_param(ac97_touch_slot, int, 0);
102 MODULE_PARM_DESC(ac97_touch_slot, "Touch screen data slot AC97 number");
103
104
105 /* flush AC97 slot 5 FIFO on pxa machines */
106 #ifdef CONFIG_PXA27x
wm97xx_acc_pen_up(struct wm97xx * wm)107 static void wm97xx_acc_pen_up(struct wm97xx *wm)
108 {
109 schedule_timeout_uninterruptible(1);
110
111 while (MISR & (1 << 2))
112 MODR;
113 }
114 #else
wm97xx_acc_pen_up(struct wm97xx * wm)115 static void wm97xx_acc_pen_up(struct wm97xx *wm)
116 {
117 unsigned int count;
118
119 schedule_timeout_uninterruptible(1);
120
121 for (count = 0; count < 16; count++)
122 MODR;
123 }
124 #endif
125
wm97xx_acc_pen_down(struct wm97xx * wm)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 * threshold 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 dev_dbg(wm->dev, "Raw coordinates: x=%x, y=%x, p=%x\n",
157 x, y, p);
158
159 /* are samples valid */
160 if ((x & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_X ||
161 (y & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_Y ||
162 (p & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_PRES)
163 goto up;
164
165 /* coordinate is good */
166 tries = 0;
167 input_report_abs(wm->input_dev, ABS_X, x & 0xfff);
168 input_report_abs(wm->input_dev, ABS_Y, y & 0xfff);
169 input_report_abs(wm->input_dev, ABS_PRESSURE, p & 0xfff);
170 input_report_key(wm->input_dev, BTN_TOUCH, (p != 0));
171 input_sync(wm->input_dev);
172 reads++;
173 } while (reads < cinfo[sp_idx].reads);
174 up:
175 return RC_PENDOWN | RC_AGAIN;
176 }
177
wm97xx_acc_startup(struct wm97xx * wm)178 static int wm97xx_acc_startup(struct wm97xx *wm)
179 {
180 int idx = 0, ret = 0;
181
182 /* check we have a codec */
183 if (wm->ac97 == NULL)
184 return -ENODEV;
185
186 /* Go you big red fire engine */
187 for (idx = 0; idx < ARRAY_SIZE(cinfo); idx++) {
188 if (wm->id != cinfo[idx].id)
189 continue;
190 sp_idx = idx;
191 if (cont_rate <= cinfo[idx].speed)
192 break;
193 }
194 wm->acc_rate = cinfo[sp_idx].code;
195 wm->acc_slot = ac97_touch_slot;
196 dev_info(wm->dev,
197 "mainstone accelerated touchscreen driver, %d samples/sec\n",
198 cinfo[sp_idx].speed);
199
200 /* IRQ driven touchscreen is used on Palm hardware */
201 if (machine_is_palmt5() || machine_is_palmtx() || machine_is_palmld()) {
202 pen_int = 1;
203 irq = 27;
204 /* There is some obscure mutant of WM9712 interbred with WM9713
205 * used on Palm HW */
206 wm->variant = WM97xx_WM1613;
207 } else if (machine_is_mainstone() && pen_int)
208 irq = 4;
209
210 if (irq) {
211 ret = gpio_request(irq, "Touchscreen IRQ");
212 if (ret)
213 goto out;
214
215 ret = gpio_direction_input(irq);
216 if (ret) {
217 gpio_free(irq);
218 goto out;
219 }
220
221 wm->pen_irq = gpio_to_irq(irq);
222 irq_set_irq_type(wm->pen_irq, IRQ_TYPE_EDGE_BOTH);
223 } else /* pen irq not supported */
224 pen_int = 0;
225
226 /* codec specific irq config */
227 if (pen_int) {
228 switch (wm->id) {
229 case WM9705_ID2:
230 break;
231 case WM9712_ID2:
232 case WM9713_ID2:
233 /* use PEN_DOWN GPIO 13 to assert IRQ on GPIO line 2 */
234 wm97xx_config_gpio(wm, WM97XX_GPIO_13, WM97XX_GPIO_IN,
235 WM97XX_GPIO_POL_HIGH,
236 WM97XX_GPIO_STICKY,
237 WM97XX_GPIO_WAKE);
238 wm97xx_config_gpio(wm, WM97XX_GPIO_2, WM97XX_GPIO_OUT,
239 WM97XX_GPIO_POL_HIGH,
240 WM97XX_GPIO_NOTSTICKY,
241 WM97XX_GPIO_NOWAKE);
242 break;
243 default:
244 dev_err(wm->dev,
245 "pen down irq not supported on this device\n");
246 pen_int = 0;
247 break;
248 }
249 }
250
251 out:
252 return ret;
253 }
254
wm97xx_acc_shutdown(struct wm97xx * wm)255 static void wm97xx_acc_shutdown(struct wm97xx *wm)
256 {
257 /* codec specific deconfig */
258 if (pen_int) {
259 if (irq)
260 gpio_free(irq);
261 wm->pen_irq = 0;
262 }
263 }
264
wm97xx_irq_enable(struct wm97xx * wm,int enable)265 static void wm97xx_irq_enable(struct wm97xx *wm, int enable)
266 {
267 if (enable)
268 enable_irq(wm->pen_irq);
269 else
270 disable_irq_nosync(wm->pen_irq);
271 }
272
273 static struct wm97xx_mach_ops mainstone_mach_ops = {
274 .acc_enabled = 1,
275 .acc_pen_up = wm97xx_acc_pen_up,
276 .acc_pen_down = wm97xx_acc_pen_down,
277 .acc_startup = wm97xx_acc_startup,
278 .acc_shutdown = wm97xx_acc_shutdown,
279 .irq_enable = wm97xx_irq_enable,
280 .irq_gpio = WM97XX_GPIO_2,
281 };
282
mainstone_wm97xx_probe(struct platform_device * pdev)283 static int mainstone_wm97xx_probe(struct platform_device *pdev)
284 {
285 struct wm97xx *wm = platform_get_drvdata(pdev);
286
287 return wm97xx_register_mach_ops(wm, &mainstone_mach_ops);
288 }
289
mainstone_wm97xx_remove(struct platform_device * pdev)290 static int mainstone_wm97xx_remove(struct platform_device *pdev)
291 {
292 struct wm97xx *wm = platform_get_drvdata(pdev);
293
294 wm97xx_unregister_mach_ops(wm);
295 return 0;
296 }
297
298 static struct platform_driver mainstone_wm97xx_driver = {
299 .probe = mainstone_wm97xx_probe,
300 .remove = mainstone_wm97xx_remove,
301 .driver = {
302 .name = "wm97xx-touch",
303 },
304 };
305 module_platform_driver(mainstone_wm97xx_driver);
306
307 /* Module information */
308 MODULE_AUTHOR("Liam Girdwood <lrg@slimlogic.co.uk>");
309 MODULE_DESCRIPTION("wm97xx continuous touch driver for mainstone");
310 MODULE_LICENSE("GPL");
311