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
34struct 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
43static 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 */
51static int sp_idx;
52
53/*
54 * Pen sampling frequency (Hz) in continuous mode.
55 */
56static int cont_rate = 200;
57module_param(cont_rate, int, 0);
58MODULE_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 */
65static int pressure;
66module_param(pressure, int, 0);
67MODULE_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 */
74static int ac97_touch_slot = 5;
75module_param(ac97_touch_slot, int, 0);
76MODULE_PARM_DESC(ac97_touch_slot, "Touch screen data slot AC97 number");
77
78
79/* flush AC97 slot 5 FIFO machines */
80static 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
90static 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);
139up:
140	return RC_PENDOWN | RC_AGAIN;
141}
142
143static 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
168static 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
176static 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
185static 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
210static 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
219static struct platform_driver zylonite_wm97xx_driver = {
220	.probe	= zylonite_wm97xx_probe,
221	.remove	= zylonite_wm97xx_remove,
222	.driver	= {
223		.name	= "wm97xx-touch",
224	},
225};
226module_platform_driver(zylonite_wm97xx_driver);
227
228/* Module information */
229MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
230MODULE_DESCRIPTION("wm97xx continuous touch driver for Zylonite");
231MODULE_LICENSE("GPL");
232