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/init.h>
24 #include <linux/delay.h>
25 #include <linux/gpio.h>
26 #include <linux/irq.h>
27 #include <linux/interrupt.h>
28 #include <linux/io.h>
29 #include <linux/wm97xx.h>
30
31 #include <mach/hardware.h>
32 #include <mach/mfp.h>
33 #include <mach/regs-ac97.h>
34
35 struct continuous {
36 u16 id; /* codec id */
37 u8 code; /* continuous code */
38 u8 reads; /* number of coord reads per read cycle */
39 u32 speed; /* number of coords per second */
40 };
41
42 #define WM_READS(sp) ((sp / HZ) + 1)
43
44 static const struct continuous cinfo[] = {
45 { WM9713_ID2, 0, WM_READS(94), 94 },
46 { WM9713_ID2, 1, WM_READS(120), 120 },
47 { WM9713_ID2, 2, WM_READS(154), 154 },
48 { WM9713_ID2, 3, WM_READS(188), 188 },
49 };
50
51 /* continuous speed index */
52 static int sp_idx;
53
54 /*
55 * Pen sampling frequency (Hz) in continuous mode.
56 */
57 static int cont_rate = 200;
58 module_param(cont_rate, int, 0);
59 MODULE_PARM_DESC(cont_rate, "Sampling rate in continuous mode (Hz)");
60
61 /*
62 * Pressure readback.
63 *
64 * Set to 1 to read back pen down pressure
65 */
66 static int pressure;
67 module_param(pressure, int, 0);
68 MODULE_PARM_DESC(pressure, "Pressure readback (1 = pressure, 0 = no pressure)");
69
70 /*
71 * AC97 touch data slot.
72 *
73 * Touch screen readback data ac97 slot
74 */
75 static int ac97_touch_slot = 5;
76 module_param(ac97_touch_slot, int, 0);
77 MODULE_PARM_DESC(ac97_touch_slot, "Touch screen data slot AC97 number");
78
79
80 /* flush AC97 slot 5 FIFO machines */
wm97xx_acc_pen_up(struct wm97xx * wm)81 static void wm97xx_acc_pen_up(struct wm97xx *wm)
82 {
83 int i;
84
85 msleep(1);
86
87 for (i = 0; i < 16; i++)
88 MODR;
89 }
90
wm97xx_acc_pen_down(struct wm97xx * wm)91 static int wm97xx_acc_pen_down(struct wm97xx *wm)
92 {
93 u16 x, y, p = 0x100 | WM97XX_ADCSEL_PRES;
94 int reads = 0;
95 static u16 last, tries;
96
97 /* When the AC97 queue has been drained we need to allow time
98 * to buffer up samples otherwise we end up spinning polling
99 * for samples. The controller can't have a suitably low
100 * threshold set to use the notifications it gives.
101 */
102 msleep(1);
103
104 if (tries > 5) {
105 tries = 0;
106 return RC_PENUP;
107 }
108
109 x = MODR;
110 if (x == last) {
111 tries++;
112 return RC_AGAIN;
113 }
114 last = x;
115 do {
116 if (reads)
117 x = MODR;
118 y = MODR;
119 if (pressure)
120 p = MODR;
121
122 dev_dbg(wm->dev, "Raw coordinates: x=%x, y=%x, p=%x\n",
123 x, y, p);
124
125 /* are samples valid */
126 if ((x & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_X ||
127 (y & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_Y ||
128 (p & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_PRES)
129 goto up;
130
131 /* coordinate is good */
132 tries = 0;
133 input_report_abs(wm->input_dev, ABS_X, x & 0xfff);
134 input_report_abs(wm->input_dev, ABS_Y, y & 0xfff);
135 input_report_abs(wm->input_dev, ABS_PRESSURE, p & 0xfff);
136 input_report_key(wm->input_dev, BTN_TOUCH, (p != 0));
137 input_sync(wm->input_dev);
138 reads++;
139 } while (reads < cinfo[sp_idx].reads);
140 up:
141 return RC_PENDOWN | RC_AGAIN;
142 }
143
wm97xx_acc_startup(struct wm97xx * wm)144 static int wm97xx_acc_startup(struct wm97xx *wm)
145 {
146 int idx;
147
148 /* check we have a codec */
149 if (wm->ac97 == NULL)
150 return -ENODEV;
151
152 /* Go you big red fire engine */
153 for (idx = 0; idx < ARRAY_SIZE(cinfo); idx++) {
154 if (wm->id != cinfo[idx].id)
155 continue;
156 sp_idx = idx;
157 if (cont_rate <= cinfo[idx].speed)
158 break;
159 }
160 wm->acc_rate = cinfo[sp_idx].code;
161 wm->acc_slot = ac97_touch_slot;
162 dev_info(wm->dev,
163 "zylonite accelerated touchscreen driver, %d samples/sec\n",
164 cinfo[sp_idx].speed);
165
166 return 0;
167 }
168
wm97xx_irq_enable(struct wm97xx * wm,int enable)169 static void wm97xx_irq_enable(struct wm97xx *wm, int enable)
170 {
171 if (enable)
172 enable_irq(wm->pen_irq);
173 else
174 disable_irq_nosync(wm->pen_irq);
175 }
176
177 static struct wm97xx_mach_ops zylonite_mach_ops = {
178 .acc_enabled = 1,
179 .acc_pen_up = wm97xx_acc_pen_up,
180 .acc_pen_down = wm97xx_acc_pen_down,
181 .acc_startup = wm97xx_acc_startup,
182 .irq_enable = wm97xx_irq_enable,
183 .irq_gpio = WM97XX_GPIO_2,
184 };
185
zylonite_wm97xx_probe(struct platform_device * pdev)186 static int zylonite_wm97xx_probe(struct platform_device *pdev)
187 {
188 struct wm97xx *wm = platform_get_drvdata(pdev);
189 int gpio_touch_irq;
190
191 if (cpu_is_pxa320())
192 gpio_touch_irq = mfp_to_gpio(MFP_PIN_GPIO15);
193 else
194 gpio_touch_irq = mfp_to_gpio(MFP_PIN_GPIO26);
195
196 wm->pen_irq = gpio_to_irq(gpio_touch_irq);
197 irq_set_irq_type(wm->pen_irq, IRQ_TYPE_EDGE_BOTH);
198
199 wm97xx_config_gpio(wm, WM97XX_GPIO_13, WM97XX_GPIO_IN,
200 WM97XX_GPIO_POL_HIGH,
201 WM97XX_GPIO_STICKY,
202 WM97XX_GPIO_WAKE);
203 wm97xx_config_gpio(wm, WM97XX_GPIO_2, WM97XX_GPIO_OUT,
204 WM97XX_GPIO_POL_HIGH,
205 WM97XX_GPIO_NOTSTICKY,
206 WM97XX_GPIO_NOWAKE);
207
208 return wm97xx_register_mach_ops(wm, &zylonite_mach_ops);
209 }
210
zylonite_wm97xx_remove(struct platform_device * pdev)211 static int zylonite_wm97xx_remove(struct platform_device *pdev)
212 {
213 struct wm97xx *wm = platform_get_drvdata(pdev);
214
215 wm97xx_unregister_mach_ops(wm);
216
217 return 0;
218 }
219
220 static struct platform_driver zylonite_wm97xx_driver = {
221 .probe = zylonite_wm97xx_probe,
222 .remove = zylonite_wm97xx_remove,
223 .driver = {
224 .name = "wm97xx-touch",
225 },
226 };
227 module_platform_driver(zylonite_wm97xx_driver);
228
229 /* Module information */
230 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
231 MODULE_DESCRIPTION("wm97xx continuous touch driver for Zylonite");
232 MODULE_LICENSE("GPL");
233