1 /*
2 * zylonite-wm97xx.c -- Zylonite Continuous Touch screen driver
3 *
4 * Copyright 2004, 2007, 2008 Wolfson Microelectronics PLC.
5 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
6 * Parts Copyright : Ian Molton <spyro@f2s.com>
7 * Andrew Zabolotny <zap@homelink.ru>
8 *
9 * This program is free software; you can redistribute it and/or modify it
10 * under the terms of the GNU General Public License as published by the
11 * Free Software Foundation; either version 2 of the License, or (at your
12 * option) any later version.
13 *
14 * Notes:
15 * This is a wm97xx extended touch driver supporting interrupt driven
16 * and continuous operation on Marvell Zylonite development systems
17 * (which have a WM9713 on board).
18 */
19
20 #include <linux/module.h>
21 #include <linux/moduleparam.h>
22 #include <linux/kernel.h>
23 #include <linux/delay.h>
24 #include <linux/gpio.h>
25 #include <linux/irq.h>
26 #include <linux/interrupt.h>
27 #include <linux/io.h>
28 #include <linux/wm97xx.h>
29
30 #include <mach/hardware.h>
31 #include <mach/mfp.h>
32 #include <mach/regs-ac97.h>
33
34 struct continuous {
35 u16 id; /* codec id */
36 u8 code; /* continuous code */
37 u8 reads; /* number of coord reads per read cycle */
38 u32 speed; /* number of coords per second */
39 };
40
41 #define WM_READS(sp) ((sp / HZ) + 1)
42
43 static const struct continuous cinfo[] = {
44 { WM9713_ID2, 0, WM_READS(94), 94 },
45 { WM9713_ID2, 1, WM_READS(120), 120 },
46 { WM9713_ID2, 2, WM_READS(154), 154 },
47 { WM9713_ID2, 3, WM_READS(188), 188 },
48 };
49
50 /* continuous speed index */
51 static int sp_idx;
52
53 /*
54 * Pen sampling frequency (Hz) in continuous mode.
55 */
56 static int cont_rate = 200;
57 module_param(cont_rate, int, 0);
58 MODULE_PARM_DESC(cont_rate, "Sampling rate in continuous mode (Hz)");
59
60 /*
61 * Pressure readback.
62 *
63 * Set to 1 to read back pen down pressure
64 */
65 static int pressure;
66 module_param(pressure, int, 0);
67 MODULE_PARM_DESC(pressure, "Pressure readback (1 = pressure, 0 = no pressure)");
68
69 /*
70 * AC97 touch data slot.
71 *
72 * Touch screen readback data ac97 slot
73 */
74 static int ac97_touch_slot = 5;
75 module_param(ac97_touch_slot, int, 0);
76 MODULE_PARM_DESC(ac97_touch_slot, "Touch screen data slot AC97 number");
77
78
79 /* flush AC97 slot 5 FIFO machines */
wm97xx_acc_pen_up(struct wm97xx * wm)80 static void wm97xx_acc_pen_up(struct wm97xx *wm)
81 {
82 int i;
83
84 msleep(1);
85
86 for (i = 0; i < 16; i++)
87 MODR;
88 }
89
wm97xx_acc_pen_down(struct wm97xx * wm)90 static int wm97xx_acc_pen_down(struct wm97xx *wm)
91 {
92 u16 x, y, p = 0x100 | WM97XX_ADCSEL_PRES;
93 int reads = 0;
94 static u16 last, tries;
95
96 /* When the AC97 queue has been drained we need to allow time
97 * to buffer up samples otherwise we end up spinning polling
98 * for samples. The controller can't have a suitably low
99 * threshold set to use the notifications it gives.
100 */
101 msleep(1);
102
103 if (tries > 5) {
104 tries = 0;
105 return RC_PENUP;
106 }
107
108 x = MODR;
109 if (x == last) {
110 tries++;
111 return RC_AGAIN;
112 }
113 last = x;
114 do {
115 if (reads)
116 x = MODR;
117 y = MODR;
118 if (pressure)
119 p = MODR;
120
121 dev_dbg(wm->dev, "Raw coordinates: x=%x, y=%x, p=%x\n",
122 x, y, p);
123
124 /* are samples valid */
125 if ((x & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_X ||
126 (y & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_Y ||
127 (p & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_PRES)
128 goto up;
129
130 /* coordinate is good */
131 tries = 0;
132 input_report_abs(wm->input_dev, ABS_X, x & 0xfff);
133 input_report_abs(wm->input_dev, ABS_Y, y & 0xfff);
134 input_report_abs(wm->input_dev, ABS_PRESSURE, p & 0xfff);
135 input_report_key(wm->input_dev, BTN_TOUCH, (p != 0));
136 input_sync(wm->input_dev);
137 reads++;
138 } while (reads < cinfo[sp_idx].reads);
139 up:
140 return RC_PENDOWN | RC_AGAIN;
141 }
142
wm97xx_acc_startup(struct wm97xx * wm)143 static int wm97xx_acc_startup(struct wm97xx *wm)
144 {
145 int idx;
146
147 /* check we have a codec */
148 if (wm->ac97 == NULL)
149 return -ENODEV;
150
151 /* Go you big red fire engine */
152 for (idx = 0; idx < ARRAY_SIZE(cinfo); idx++) {
153 if (wm->id != cinfo[idx].id)
154 continue;
155 sp_idx = idx;
156 if (cont_rate <= cinfo[idx].speed)
157 break;
158 }
159 wm->acc_rate = cinfo[sp_idx].code;
160 wm->acc_slot = ac97_touch_slot;
161 dev_info(wm->dev,
162 "zylonite accelerated touchscreen driver, %d samples/sec\n",
163 cinfo[sp_idx].speed);
164
165 return 0;
166 }
167
wm97xx_irq_enable(struct wm97xx * wm,int enable)168 static void wm97xx_irq_enable(struct wm97xx *wm, int enable)
169 {
170 if (enable)
171 enable_irq(wm->pen_irq);
172 else
173 disable_irq_nosync(wm->pen_irq);
174 }
175
176 static struct wm97xx_mach_ops zylonite_mach_ops = {
177 .acc_enabled = 1,
178 .acc_pen_up = wm97xx_acc_pen_up,
179 .acc_pen_down = wm97xx_acc_pen_down,
180 .acc_startup = wm97xx_acc_startup,
181 .irq_enable = wm97xx_irq_enable,
182 .irq_gpio = WM97XX_GPIO_2,
183 };
184
zylonite_wm97xx_probe(struct platform_device * pdev)185 static int zylonite_wm97xx_probe(struct platform_device *pdev)
186 {
187 struct wm97xx *wm = platform_get_drvdata(pdev);
188 int gpio_touch_irq;
189
190 if (cpu_is_pxa320())
191 gpio_touch_irq = mfp_to_gpio(MFP_PIN_GPIO15);
192 else
193 gpio_touch_irq = mfp_to_gpio(MFP_PIN_GPIO26);
194
195 wm->pen_irq = gpio_to_irq(gpio_touch_irq);
196 irq_set_irq_type(wm->pen_irq, IRQ_TYPE_EDGE_BOTH);
197
198 wm97xx_config_gpio(wm, WM97XX_GPIO_13, WM97XX_GPIO_IN,
199 WM97XX_GPIO_POL_HIGH,
200 WM97XX_GPIO_STICKY,
201 WM97XX_GPIO_WAKE);
202 wm97xx_config_gpio(wm, WM97XX_GPIO_2, WM97XX_GPIO_OUT,
203 WM97XX_GPIO_POL_HIGH,
204 WM97XX_GPIO_NOTSTICKY,
205 WM97XX_GPIO_NOWAKE);
206
207 return wm97xx_register_mach_ops(wm, &zylonite_mach_ops);
208 }
209
zylonite_wm97xx_remove(struct platform_device * pdev)210 static int zylonite_wm97xx_remove(struct platform_device *pdev)
211 {
212 struct wm97xx *wm = platform_get_drvdata(pdev);
213
214 wm97xx_unregister_mach_ops(wm);
215
216 return 0;
217 }
218
219 static struct platform_driver zylonite_wm97xx_driver = {
220 .probe = zylonite_wm97xx_probe,
221 .remove = zylonite_wm97xx_remove,
222 .driver = {
223 .name = "wm97xx-touch",
224 },
225 };
226 module_platform_driver(zylonite_wm97xx_driver);
227
228 /* Module information */
229 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
230 MODULE_DESCRIPTION("wm97xx continuous touch driver for Zylonite");
231 MODULE_LICENSE("GPL");
232