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/init.h>
29#include <linux/delay.h>
30#include <linux/irq.h>
31#include <linux/interrupt.h>
32#include <linux/wm97xx.h>
33#include <linux/io.h>
34#include <linux/gpio.h>
35
36#include <mach/regs-ac97.h>
37
38#include <asm/mach-types.h>
39
40struct continuous {
41	u16 id;    /* codec id */
42	u8 code;   /* continuous code */
43	u8 reads;  /* number of coord reads per read cycle */
44	u32 speed; /* number of coords per second */
45};
46
47#define WM_READS(sp) ((sp / HZ) + 1)
48
49static const struct continuous cinfo[] = {
50	{WM9705_ID2, 0, WM_READS(94), 94},
51	{WM9705_ID2, 1, WM_READS(188), 188},
52	{WM9705_ID2, 2, WM_READS(375), 375},
53	{WM9705_ID2, 3, WM_READS(750), 750},
54	{WM9712_ID2, 0, WM_READS(94), 94},
55	{WM9712_ID2, 1, WM_READS(188), 188},
56	{WM9712_ID2, 2, WM_READS(375), 375},
57	{WM9712_ID2, 3, WM_READS(750), 750},
58	{WM9713_ID2, 0, WM_READS(94), 94},
59	{WM9713_ID2, 1, WM_READS(120), 120},
60	{WM9713_ID2, 2, WM_READS(154), 154},
61	{WM9713_ID2, 3, WM_READS(188), 188},
62};
63
64/* continuous speed index */
65static int sp_idx;
66static u16 last, tries;
67static int irq;
68
69/*
70 * Pen sampling frequency (Hz) in continuous mode.
71 */
72static int cont_rate = 200;
73module_param(cont_rate, int, 0);
74MODULE_PARM_DESC(cont_rate, "Sampling rate in continuous mode (Hz)");
75
76/*
77 * Pen down detection.
78 *
79 * This driver can either poll or use an interrupt to indicate a pen down
80 * event. If the irq request fails then it will fall back to polling mode.
81 */
82static int pen_int;
83module_param(pen_int, int, 0);
84MODULE_PARM_DESC(pen_int, "Pen down detection (1 = interrupt, 0 = polling)");
85
86/*
87 * Pressure readback.
88 *
89 * Set to 1 to read back pen down pressure
90 */
91static int pressure;
92module_param(pressure, int, 0);
93MODULE_PARM_DESC(pressure, "Pressure readback (1 = pressure, 0 = no pressure)");
94
95/*
96 * AC97 touch data slot.
97 *
98 * Touch screen readback data ac97 slot
99 */
100static int ac97_touch_slot = 5;
101module_param(ac97_touch_slot, int, 0);
102MODULE_PARM_DESC(ac97_touch_slot, "Touch screen data slot AC97 number");
103
104
105/* flush AC97 slot 5 FIFO on pxa machines */
106#ifdef CONFIG_PXA27x
107static void wm97xx_acc_pen_up(struct wm97xx *wm)
108{
109	schedule_timeout_uninterruptible(1);
110
111	while (MISR & (1 << 2))
112		MODR;
113}
114#else
115static void wm97xx_acc_pen_up(struct wm97xx *wm)
116{
117	unsigned int count;
118
119	schedule_timeout_uninterruptible(1);
120
121	for (count = 0; count < 16; count++)
122		MODR;
123}
124#endif
125
126static int wm97xx_acc_pen_down(struct wm97xx *wm)
127{
128	u16 x, y, p = 0x100 | WM97XX_ADCSEL_PRES;
129	int reads = 0;
130
131	/* When the AC97 queue has been drained we need to allow time
132	 * to buffer up samples otherwise we end up spinning polling
133	 * for samples.  The controller can't have a suitably low
134	 * threshold set to use the notifications it gives.
135	 */
136	schedule_timeout_uninterruptible(1);
137
138	if (tries > 5) {
139		tries = 0;
140		return RC_PENUP;
141	}
142
143	x = MODR;
144	if (x == last) {
145		tries++;
146		return RC_AGAIN;
147	}
148	last = x;
149	do {
150		if (reads)
151			x = MODR;
152		y = MODR;
153		if (pressure)
154			p = MODR;
155
156		dev_dbg(wm->dev, "Raw coordinates: x=%x, y=%x, p=%x\n",
157			x, y, p);
158
159		/* are samples valid */
160		if ((x & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_X ||
161		    (y & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_Y ||
162		    (p & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_PRES)
163			goto up;
164
165		/* coordinate is good */
166		tries = 0;
167		input_report_abs(wm->input_dev, ABS_X, x & 0xfff);
168		input_report_abs(wm->input_dev, ABS_Y, y & 0xfff);
169		input_report_abs(wm->input_dev, ABS_PRESSURE, p & 0xfff);
170		input_report_key(wm->input_dev, BTN_TOUCH, (p != 0));
171		input_sync(wm->input_dev);
172		reads++;
173	} while (reads < cinfo[sp_idx].reads);
174up:
175	return RC_PENDOWN | RC_AGAIN;
176}
177
178static int wm97xx_acc_startup(struct wm97xx *wm)
179{
180	int idx = 0, ret = 0;
181
182	/* check we have a codec */
183	if (wm->ac97 == NULL)
184		return -ENODEV;
185
186	/* Go you big red fire engine */
187	for (idx = 0; idx < ARRAY_SIZE(cinfo); idx++) {
188		if (wm->id != cinfo[idx].id)
189			continue;
190		sp_idx = idx;
191		if (cont_rate <= cinfo[idx].speed)
192			break;
193	}
194	wm->acc_rate = cinfo[sp_idx].code;
195	wm->acc_slot = ac97_touch_slot;
196	dev_info(wm->dev,
197		 "mainstone accelerated touchscreen driver, %d samples/sec\n",
198		 cinfo[sp_idx].speed);
199
200	/* IRQ driven touchscreen is used on Palm hardware */
201	if (machine_is_palmt5() || machine_is_palmtx() || machine_is_palmld()) {
202		pen_int = 1;
203		irq = 27;
204		/* There is some obscure mutant of WM9712 interbred with WM9713
205		 * used on Palm HW */
206		wm->variant = WM97xx_WM1613;
207	} else if (machine_is_mainstone() && pen_int)
208		irq = 4;
209
210	if (irq) {
211		ret = gpio_request(irq, "Touchscreen IRQ");
212		if (ret)
213			goto out;
214
215		ret = gpio_direction_input(irq);
216		if (ret) {
217			gpio_free(irq);
218			goto out;
219		}
220
221		wm->pen_irq = gpio_to_irq(irq);
222		irq_set_irq_type(wm->pen_irq, IRQ_TYPE_EDGE_BOTH);
223	} else /* pen irq not supported */
224		pen_int = 0;
225
226	/* codec specific irq config */
227	if (pen_int) {
228		switch (wm->id) {
229		case WM9705_ID2:
230			break;
231		case WM9712_ID2:
232		case WM9713_ID2:
233			/* use PEN_DOWN GPIO 13 to assert IRQ on GPIO line 2 */
234			wm97xx_config_gpio(wm, WM97XX_GPIO_13, WM97XX_GPIO_IN,
235					   WM97XX_GPIO_POL_HIGH,
236					   WM97XX_GPIO_STICKY,
237					   WM97XX_GPIO_WAKE);
238			wm97xx_config_gpio(wm, WM97XX_GPIO_2, WM97XX_GPIO_OUT,
239					   WM97XX_GPIO_POL_HIGH,
240					   WM97XX_GPIO_NOTSTICKY,
241					   WM97XX_GPIO_NOWAKE);
242			break;
243		default:
244			dev_err(wm->dev,
245				"pen down irq not supported on this device\n");
246			pen_int = 0;
247			break;
248		}
249	}
250
251out:
252	return ret;
253}
254
255static void wm97xx_acc_shutdown(struct wm97xx *wm)
256{
257	/* codec specific deconfig */
258	if (pen_int) {
259		if (irq)
260			gpio_free(irq);
261		wm->pen_irq = 0;
262	}
263}
264
265static void wm97xx_irq_enable(struct wm97xx *wm, int enable)
266{
267	if (enable)
268		enable_irq(wm->pen_irq);
269	else
270		disable_irq_nosync(wm->pen_irq);
271}
272
273static struct wm97xx_mach_ops mainstone_mach_ops = {
274	.acc_enabled = 1,
275	.acc_pen_up = wm97xx_acc_pen_up,
276	.acc_pen_down = wm97xx_acc_pen_down,
277	.acc_startup = wm97xx_acc_startup,
278	.acc_shutdown = wm97xx_acc_shutdown,
279	.irq_enable = wm97xx_irq_enable,
280	.irq_gpio = WM97XX_GPIO_2,
281};
282
283static int mainstone_wm97xx_probe(struct platform_device *pdev)
284{
285	struct wm97xx *wm = platform_get_drvdata(pdev);
286
287	return wm97xx_register_mach_ops(wm, &mainstone_mach_ops);
288}
289
290static int mainstone_wm97xx_remove(struct platform_device *pdev)
291{
292	struct wm97xx *wm = platform_get_drvdata(pdev);
293
294	wm97xx_unregister_mach_ops(wm);
295	return 0;
296}
297
298static struct platform_driver mainstone_wm97xx_driver = {
299	.probe = mainstone_wm97xx_probe,
300	.remove = mainstone_wm97xx_remove,
301	.driver = {
302		.name = "wm97xx-touch",
303	},
304};
305module_platform_driver(mainstone_wm97xx_driver);
306
307/* Module information */
308MODULE_AUTHOR("Liam Girdwood <lrg@slimlogic.co.uk>");
309MODULE_DESCRIPTION("wm97xx continuous touch driver for mainstone");
310MODULE_LICENSE("GPL");
311