1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * zylonite-wm97xx.c -- Zylonite Continuous Touch screen driver
4 *
5 * Copyright 2004, 2007, 2008 Wolfson Microelectronics PLC.
6 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
7 * Parts Copyright : Ian Molton <spyro@f2s.com>
8 * Andrew Zabolotny <zap@homelink.ru>
9 *
10 * Notes:
11 * This is a wm97xx extended touch driver supporting interrupt driven
12 * and continuous operation on Marvell Zylonite development systems
13 * (which have a WM9713 on board).
14 */
15
16 #include <linux/module.h>
17 #include <linux/moduleparam.h>
18 #include <linux/kernel.h>
19 #include <linux/delay.h>
20 #include <linux/gpio.h>
21 #include <linux/irq.h>
22 #include <linux/interrupt.h>
23 #include <linux/io.h>
24 #include <linux/wm97xx.h>
25
26 #include <mach/hardware.h>
27 #include <mach/mfp.h>
28 #include <mach/regs-ac97.h>
29
30 struct continuous {
31 u16 id; /* codec id */
32 u8 code; /* continuous code */
33 u8 reads; /* number of coord reads per read cycle */
34 u32 speed; /* number of coords per second */
35 };
36
37 #define WM_READS(sp) ((sp / HZ) + 1)
38
39 static const struct continuous cinfo[] = {
40 { WM9713_ID2, 0, WM_READS(94), 94 },
41 { WM9713_ID2, 1, WM_READS(120), 120 },
42 { WM9713_ID2, 2, WM_READS(154), 154 },
43 { WM9713_ID2, 3, WM_READS(188), 188 },
44 };
45
46 /* continuous speed index */
47 static int sp_idx;
48
49 /*
50 * Pen sampling frequency (Hz) in continuous mode.
51 */
52 static int cont_rate = 200;
53 module_param(cont_rate, int, 0);
54 MODULE_PARM_DESC(cont_rate, "Sampling rate in continuous mode (Hz)");
55
56 /*
57 * Pressure readback.
58 *
59 * Set to 1 to read back pen down pressure
60 */
61 static int pressure;
62 module_param(pressure, int, 0);
63 MODULE_PARM_DESC(pressure, "Pressure readback (1 = pressure, 0 = no pressure)");
64
65 /*
66 * AC97 touch data slot.
67 *
68 * Touch screen readback data ac97 slot
69 */
70 static int ac97_touch_slot = 5;
71 module_param(ac97_touch_slot, int, 0);
72 MODULE_PARM_DESC(ac97_touch_slot, "Touch screen data slot AC97 number");
73
74
75 /* flush AC97 slot 5 FIFO machines */
wm97xx_acc_pen_up(struct wm97xx * wm)76 static void wm97xx_acc_pen_up(struct wm97xx *wm)
77 {
78 int i;
79
80 msleep(1);
81
82 for (i = 0; i < 16; i++)
83 MODR;
84 }
85
wm97xx_acc_pen_down(struct wm97xx * wm)86 static int wm97xx_acc_pen_down(struct wm97xx *wm)
87 {
88 u16 x, y, p = 0x100 | WM97XX_ADCSEL_PRES;
89 int reads = 0;
90 static u16 last, tries;
91
92 /* When the AC97 queue has been drained we need to allow time
93 * to buffer up samples otherwise we end up spinning polling
94 * for samples. The controller can't have a suitably low
95 * threshold set to use the notifications it gives.
96 */
97 msleep(1);
98
99 if (tries > 5) {
100 tries = 0;
101 return RC_PENUP;
102 }
103
104 x = MODR;
105 if (x == last) {
106 tries++;
107 return RC_AGAIN;
108 }
109 last = x;
110 do {
111 if (reads)
112 x = MODR;
113 y = MODR;
114 if (pressure)
115 p = MODR;
116
117 dev_dbg(wm->dev, "Raw coordinates: x=%x, y=%x, p=%x\n",
118 x, y, p);
119
120 /* are samples valid */
121 if ((x & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_X ||
122 (y & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_Y ||
123 (p & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_PRES)
124 goto up;
125
126 /* coordinate is good */
127 tries = 0;
128 input_report_abs(wm->input_dev, ABS_X, x & 0xfff);
129 input_report_abs(wm->input_dev, ABS_Y, y & 0xfff);
130 input_report_abs(wm->input_dev, ABS_PRESSURE, p & 0xfff);
131 input_report_key(wm->input_dev, BTN_TOUCH, (p != 0));
132 input_sync(wm->input_dev);
133 reads++;
134 } while (reads < cinfo[sp_idx].reads);
135 up:
136 return RC_PENDOWN | RC_AGAIN;
137 }
138
wm97xx_acc_startup(struct wm97xx * wm)139 static int wm97xx_acc_startup(struct wm97xx *wm)
140 {
141 int idx;
142
143 /* check we have a codec */
144 if (wm->ac97 == NULL)
145 return -ENODEV;
146
147 /* Go you big red fire engine */
148 for (idx = 0; idx < ARRAY_SIZE(cinfo); idx++) {
149 if (wm->id != cinfo[idx].id)
150 continue;
151 sp_idx = idx;
152 if (cont_rate <= cinfo[idx].speed)
153 break;
154 }
155 wm->acc_rate = cinfo[sp_idx].code;
156 wm->acc_slot = ac97_touch_slot;
157 dev_info(wm->dev,
158 "zylonite accelerated touchscreen driver, %d samples/sec\n",
159 cinfo[sp_idx].speed);
160
161 return 0;
162 }
163
wm97xx_irq_enable(struct wm97xx * wm,int enable)164 static void wm97xx_irq_enable(struct wm97xx *wm, int enable)
165 {
166 if (enable)
167 enable_irq(wm->pen_irq);
168 else
169 disable_irq_nosync(wm->pen_irq);
170 }
171
172 static struct wm97xx_mach_ops zylonite_mach_ops = {
173 .acc_enabled = 1,
174 .acc_pen_up = wm97xx_acc_pen_up,
175 .acc_pen_down = wm97xx_acc_pen_down,
176 .acc_startup = wm97xx_acc_startup,
177 .irq_enable = wm97xx_irq_enable,
178 .irq_gpio = WM97XX_GPIO_2,
179 };
180
zylonite_wm97xx_probe(struct platform_device * pdev)181 static int zylonite_wm97xx_probe(struct platform_device *pdev)
182 {
183 struct wm97xx *wm = platform_get_drvdata(pdev);
184 int gpio_touch_irq;
185
186 if (cpu_is_pxa320())
187 gpio_touch_irq = mfp_to_gpio(MFP_PIN_GPIO15);
188 else
189 gpio_touch_irq = mfp_to_gpio(MFP_PIN_GPIO26);
190
191 wm->pen_irq = gpio_to_irq(gpio_touch_irq);
192 irq_set_irq_type(wm->pen_irq, IRQ_TYPE_EDGE_BOTH);
193
194 wm97xx_config_gpio(wm, WM97XX_GPIO_13, WM97XX_GPIO_IN,
195 WM97XX_GPIO_POL_HIGH,
196 WM97XX_GPIO_STICKY,
197 WM97XX_GPIO_WAKE);
198 wm97xx_config_gpio(wm, WM97XX_GPIO_2, WM97XX_GPIO_OUT,
199 WM97XX_GPIO_POL_HIGH,
200 WM97XX_GPIO_NOTSTICKY,
201 WM97XX_GPIO_NOWAKE);
202
203 return wm97xx_register_mach_ops(wm, &zylonite_mach_ops);
204 }
205
zylonite_wm97xx_remove(struct platform_device * pdev)206 static int zylonite_wm97xx_remove(struct platform_device *pdev)
207 {
208 struct wm97xx *wm = platform_get_drvdata(pdev);
209
210 wm97xx_unregister_mach_ops(wm);
211
212 return 0;
213 }
214
215 static struct platform_driver zylonite_wm97xx_driver = {
216 .probe = zylonite_wm97xx_probe,
217 .remove = zylonite_wm97xx_remove,
218 .driver = {
219 .name = "wm97xx-touch",
220 },
221 };
222 module_platform_driver(zylonite_wm97xx_driver);
223
224 /* Module information */
225 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
226 MODULE_DESCRIPTION("wm97xx continuous touch driver for Zylonite");
227 MODULE_LICENSE("GPL");
228