1/*
2 * mainstone-wm97xx.c  --  Mainstone Continuous Touch screen driver for
3 *                         Wolfson WM97xx AC97 Codecs.
4 *
5 * Copyright 2004, 2007 Wolfson Microelectronics PLC.
6 * Author: Liam Girdwood <lrg@slimlogic.co.uk>
7 * Parts Copyright : Ian Molton <spyro@f2s.com>
8 *                   Andrew Zabolotny <zap@homelink.ru>
9 *
10 *  This program is free software; you can redistribute  it and/or modify it
11 *  under  the terms of  the GNU General  Public License as published by the
12 *  Free Software Foundation;  either version 2 of the  License, or (at your
13 *  option) any later version.
14 *
15 * Notes:
16 *     This is a wm97xx extended touch driver to capture touch
17 *     data in a continuous manner on the Intel XScale architecture
18 *
19 *  Features:
20 *       - codecs supported:- WM9705, WM9712, WM9713
21 *       - processors supported:- Intel XScale PXA25x, PXA26x, PXA27x
22 *
23 */
24
25#include <linux/module.h>
26#include <linux/moduleparam.h>
27#include <linux/kernel.h>
28#include <linux/delay.h>
29#include <linux/irq.h>
30#include <linux/interrupt.h>
31#include <linux/wm97xx.h>
32#include <linux/io.h>
33#include <linux/gpio.h>
34
35#include <mach/regs-ac97.h>
36
37#include <asm/mach-types.h>
38
39struct continuous {
40	u16 id;    /* codec id */
41	u8 code;   /* continuous code */
42	u8 reads;  /* number of coord reads per read cycle */
43	u32 speed; /* number of coords per second */
44};
45
46#define WM_READS(sp) ((sp / HZ) + 1)
47
48static const struct continuous cinfo[] = {
49	{WM9705_ID2, 0, WM_READS(94), 94},
50	{WM9705_ID2, 1, WM_READS(188), 188},
51	{WM9705_ID2, 2, WM_READS(375), 375},
52	{WM9705_ID2, 3, WM_READS(750), 750},
53	{WM9712_ID2, 0, WM_READS(94), 94},
54	{WM9712_ID2, 1, WM_READS(188), 188},
55	{WM9712_ID2, 2, WM_READS(375), 375},
56	{WM9712_ID2, 3, WM_READS(750), 750},
57	{WM9713_ID2, 0, WM_READS(94), 94},
58	{WM9713_ID2, 1, WM_READS(120), 120},
59	{WM9713_ID2, 2, WM_READS(154), 154},
60	{WM9713_ID2, 3, WM_READS(188), 188},
61};
62
63/* continuous speed index */
64static int sp_idx;
65static u16 last, tries;
66static int irq;
67
68/*
69 * Pen sampling frequency (Hz) in continuous mode.
70 */
71static int cont_rate = 200;
72module_param(cont_rate, int, 0);
73MODULE_PARM_DESC(cont_rate, "Sampling rate in continuous mode (Hz)");
74
75/*
76 * Pen down detection.
77 *
78 * This driver can either poll or use an interrupt to indicate a pen down
79 * event. If the irq request fails then it will fall back to polling mode.
80 */
81static int pen_int;
82module_param(pen_int, int, 0);
83MODULE_PARM_DESC(pen_int, "Pen down detection (1 = interrupt, 0 = polling)");
84
85/*
86 * Pressure readback.
87 *
88 * Set to 1 to read back pen down pressure
89 */
90static int pressure;
91module_param(pressure, int, 0);
92MODULE_PARM_DESC(pressure, "Pressure readback (1 = pressure, 0 = no pressure)");
93
94/*
95 * AC97 touch data slot.
96 *
97 * Touch screen readback data ac97 slot
98 */
99static int ac97_touch_slot = 5;
100module_param(ac97_touch_slot, int, 0);
101MODULE_PARM_DESC(ac97_touch_slot, "Touch screen data slot AC97 number");
102
103
104/* flush AC97 slot 5 FIFO on pxa machines */
105#ifdef CONFIG_PXA27x
106static void wm97xx_acc_pen_up(struct wm97xx *wm)
107{
108	schedule_timeout_uninterruptible(1);
109
110	while (MISR & (1 << 2))
111		MODR;
112}
113#else
114static void wm97xx_acc_pen_up(struct wm97xx *wm)
115{
116	unsigned int count;
117
118	schedule_timeout_uninterruptible(1);
119
120	for (count = 0; count < 16; count++)
121		MODR;
122}
123#endif
124
125static int wm97xx_acc_pen_down(struct wm97xx *wm)
126{
127	u16 x, y, p = 0x100 | WM97XX_ADCSEL_PRES;
128	int reads = 0;
129
130	/* When the AC97 queue has been drained we need to allow time
131	 * to buffer up samples otherwise we end up spinning polling
132	 * for samples.  The controller can't have a suitably low
133	 * threshold set to use the notifications it gives.
134	 */
135	schedule_timeout_uninterruptible(1);
136
137	if (tries > 5) {
138		tries = 0;
139		return RC_PENUP;
140	}
141
142	x = MODR;
143	if (x == last) {
144		tries++;
145		return RC_AGAIN;
146	}
147	last = x;
148	do {
149		if (reads)
150			x = MODR;
151		y = MODR;
152		if (pressure)
153			p = MODR;
154
155		dev_dbg(wm->dev, "Raw coordinates: x=%x, y=%x, p=%x\n",
156			x, y, p);
157
158		/* are samples valid */
159		if ((x & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_X ||
160		    (y & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_Y ||
161		    (p & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_PRES)
162			goto up;
163
164		/* coordinate is good */
165		tries = 0;
166		input_report_abs(wm->input_dev, ABS_X, x & 0xfff);
167		input_report_abs(wm->input_dev, ABS_Y, y & 0xfff);
168		input_report_abs(wm->input_dev, ABS_PRESSURE, p & 0xfff);
169		input_report_key(wm->input_dev, BTN_TOUCH, (p != 0));
170		input_sync(wm->input_dev);
171		reads++;
172	} while (reads < cinfo[sp_idx].reads);
173up:
174	return RC_PENDOWN | RC_AGAIN;
175}
176
177static int wm97xx_acc_startup(struct wm97xx *wm)
178{
179	int idx = 0, ret = 0;
180
181	/* check we have a codec */
182	if (wm->ac97 == NULL)
183		return -ENODEV;
184
185	/* Go you big red fire engine */
186	for (idx = 0; idx < ARRAY_SIZE(cinfo); idx++) {
187		if (wm->id != cinfo[idx].id)
188			continue;
189		sp_idx = idx;
190		if (cont_rate <= cinfo[idx].speed)
191			break;
192	}
193	wm->acc_rate = cinfo[sp_idx].code;
194	wm->acc_slot = ac97_touch_slot;
195	dev_info(wm->dev,
196		 "mainstone accelerated touchscreen driver, %d samples/sec\n",
197		 cinfo[sp_idx].speed);
198
199	/* IRQ driven touchscreen is used on Palm hardware */
200	if (machine_is_palmt5() || machine_is_palmtx() || machine_is_palmld()) {
201		pen_int = 1;
202		irq = 27;
203		/* There is some obscure mutant of WM9712 interbred with WM9713
204		 * used on Palm HW */
205		wm->variant = WM97xx_WM1613;
206	} else if (machine_is_mainstone() && pen_int)
207		irq = 4;
208
209	if (irq) {
210		ret = gpio_request(irq, "Touchscreen IRQ");
211		if (ret)
212			goto out;
213
214		ret = gpio_direction_input(irq);
215		if (ret) {
216			gpio_free(irq);
217			goto out;
218		}
219
220		wm->pen_irq = gpio_to_irq(irq);
221		irq_set_irq_type(wm->pen_irq, IRQ_TYPE_EDGE_BOTH);
222	} else /* pen irq not supported */
223		pen_int = 0;
224
225	/* codec specific irq config */
226	if (pen_int) {
227		switch (wm->id) {
228		case WM9705_ID2:
229			break;
230		case WM9712_ID2:
231		case WM9713_ID2:
232			/* use PEN_DOWN GPIO 13 to assert IRQ on GPIO line 2 */
233			wm97xx_config_gpio(wm, WM97XX_GPIO_13, WM97XX_GPIO_IN,
234					   WM97XX_GPIO_POL_HIGH,
235					   WM97XX_GPIO_STICKY,
236					   WM97XX_GPIO_WAKE);
237			wm97xx_config_gpio(wm, WM97XX_GPIO_2, WM97XX_GPIO_OUT,
238					   WM97XX_GPIO_POL_HIGH,
239					   WM97XX_GPIO_NOTSTICKY,
240					   WM97XX_GPIO_NOWAKE);
241			break;
242		default:
243			dev_err(wm->dev,
244				"pen down irq not supported on this device\n");
245			pen_int = 0;
246			break;
247		}
248	}
249
250out:
251	return ret;
252}
253
254static void wm97xx_acc_shutdown(struct wm97xx *wm)
255{
256	/* codec specific deconfig */
257	if (pen_int) {
258		if (irq)
259			gpio_free(irq);
260		wm->pen_irq = 0;
261	}
262}
263
264static void wm97xx_irq_enable(struct wm97xx *wm, int enable)
265{
266	if (enable)
267		enable_irq(wm->pen_irq);
268	else
269		disable_irq_nosync(wm->pen_irq);
270}
271
272static struct wm97xx_mach_ops mainstone_mach_ops = {
273	.acc_enabled = 1,
274	.acc_pen_up = wm97xx_acc_pen_up,
275	.acc_pen_down = wm97xx_acc_pen_down,
276	.acc_startup = wm97xx_acc_startup,
277	.acc_shutdown = wm97xx_acc_shutdown,
278	.irq_enable = wm97xx_irq_enable,
279	.irq_gpio = WM97XX_GPIO_2,
280};
281
282static int mainstone_wm97xx_probe(struct platform_device *pdev)
283{
284	struct wm97xx *wm = platform_get_drvdata(pdev);
285
286	return wm97xx_register_mach_ops(wm, &mainstone_mach_ops);
287}
288
289static int mainstone_wm97xx_remove(struct platform_device *pdev)
290{
291	struct wm97xx *wm = platform_get_drvdata(pdev);
292
293	wm97xx_unregister_mach_ops(wm);
294	return 0;
295}
296
297static struct platform_driver mainstone_wm97xx_driver = {
298	.probe = mainstone_wm97xx_probe,
299	.remove = mainstone_wm97xx_remove,
300	.driver = {
301		.name = "wm97xx-touch",
302	},
303};
304module_platform_driver(mainstone_wm97xx_driver);
305
306/* Module information */
307MODULE_AUTHOR("Liam Girdwood <lrg@slimlogic.co.uk>");
308MODULE_DESCRIPTION("wm97xx continuous touch driver for mainstone");
309MODULE_LICENSE("GPL");
310