2 * zylonite-wm97xx.c -- Zylonite Continuous Touch screen driver
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>
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.
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).
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/irq.h>
26 #include <linux/interrupt.h>
28 #include <linux/wm97xx.h>
30 #include <mach/hardware.h>
32 #include <mach/regs-ac97.h>
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 */
41 #define WM_READS(sp) ((sp / HZ) + 1)
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 },
50 /* continuous speed index */
54 * Pen sampling frequency (Hz) in continuous mode.
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)");
63 * Set to 1 to read back pen down pressure
66 module_param(pressure, int, 0);
67 MODULE_PARM_DESC(pressure, "Pressure readback (1 = pressure, 0 = no pressure)");
70 * AC97 touch data slot.
72 * Touch screen readback data ac97 slot
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");
79 /* flush AC97 slot 5 FIFO machines */
80 static void wm97xx_acc_pen_up(struct wm97xx *wm)
86 for (i = 0; i < 16; i++)
90 static int wm97xx_acc_pen_down(struct wm97xx *wm)
92 u16 x, y, p = 0x100 | WM97XX_ADCSEL_PRES;
94 static u16 last, tries;
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 * threashold set to use the notifications it gives.
121 /* are samples valid */
122 if ((x & WM97XX_ADCSRC_MASK) != WM97XX_ADCSEL_X ||
123 (y & WM97XX_ADCSRC_MASK) != WM97XX_ADCSEL_Y ||
124 (p & WM97XX_ADCSRC_MASK) != WM97XX_ADCSEL_PRES)
127 /* coordinate is good */
129 input_report_abs(wm->input_dev, ABS_X, x & 0xfff);
130 input_report_abs(wm->input_dev, ABS_Y, y & 0xfff);
131 input_report_abs(wm->input_dev, ABS_PRESSURE, p & 0xfff);
132 input_report_key(wm->input_dev, BTN_TOUCH, (p != 0));
133 input_sync(wm->input_dev);
135 } while (reads < cinfo[sp_idx].reads);
137 return RC_PENDOWN | RC_AGAIN;
140 static int wm97xx_acc_startup(struct wm97xx *wm)
144 /* check we have a codec */
145 if (wm->ac97 == NULL)
148 /* Go you big red fire engine */
149 for (idx = 0; idx < ARRAY_SIZE(cinfo); idx++) {
150 if (wm->id != cinfo[idx].id)
153 if (cont_rate <= cinfo[idx].speed)
156 wm->acc_rate = cinfo[sp_idx].code;
157 wm->acc_slot = ac97_touch_slot;
159 "zylonite accelerated touchscreen driver, %d samples/sec\n",
160 cinfo[sp_idx].speed);
165 static void wm97xx_irq_enable(struct wm97xx *wm, int enable)
168 enable_irq(wm->pen_irq);
170 disable_irq_nosync(wm->pen_irq);
173 static struct wm97xx_mach_ops zylonite_mach_ops = {
175 .acc_pen_up = wm97xx_acc_pen_up,
176 .acc_pen_down = wm97xx_acc_pen_down,
177 .acc_startup = wm97xx_acc_startup,
178 .irq_enable = wm97xx_irq_enable,
179 .irq_gpio = WM97XX_GPIO_2,
182 static int zylonite_wm97xx_probe(struct platform_device *pdev)
184 struct wm97xx *wm = platform_get_drvdata(pdev);
188 gpio_touch_irq = mfp_to_gpio(MFP_PIN_GPIO15);
190 gpio_touch_irq = mfp_to_gpio(MFP_PIN_GPIO26);
192 wm->pen_irq = IRQ_GPIO(gpio_touch_irq);
193 set_irq_type(IRQ_GPIO(gpio_touch_irq), IRQ_TYPE_EDGE_BOTH);
195 wm97xx_config_gpio(wm, WM97XX_GPIO_13, WM97XX_GPIO_IN,
196 WM97XX_GPIO_POL_HIGH,
199 wm97xx_config_gpio(wm, WM97XX_GPIO_2, WM97XX_GPIO_OUT,
200 WM97XX_GPIO_POL_HIGH,
201 WM97XX_GPIO_NOTSTICKY,
204 return wm97xx_register_mach_ops(wm, &zylonite_mach_ops);
207 static int zylonite_wm97xx_remove(struct platform_device *pdev)
209 struct wm97xx *wm = platform_get_drvdata(pdev);
211 wm97xx_unregister_mach_ops(wm);
216 static struct platform_driver zylonite_wm97xx_driver = {
217 .probe = zylonite_wm97xx_probe,
218 .remove = zylonite_wm97xx_remove,
220 .name = "wm97xx-touch",
224 static int __init zylonite_wm97xx_init(void)
226 return platform_driver_register(&zylonite_wm97xx_driver);
229 static void __exit zylonite_wm97xx_exit(void)
231 platform_driver_unregister(&zylonite_wm97xx_driver);
234 module_init(zylonite_wm97xx_init);
235 module_exit(zylonite_wm97xx_exit);
237 /* Module information */
238 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
239 MODULE_DESCRIPTION("wm97xx continuous touch driver for Zylonite");
240 MODULE_LICENSE("GPL");