1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * mainstone-wm97xx.c  --  Mainstone Continuous Touch screen driver for
4 *                         Wolfson WM97xx AC97 Codecs.
5 *
6 * Copyright 2004, 2007 Wolfson Microelectronics PLC.
7 * Author: Liam Girdwood <lrg@slimlogic.co.uk>
8 * Parts Copyright : Ian Molton <spyro@f2s.com>
9 *                   Andrew Zabolotny <zap@homelink.ru>
10 *
11 * Notes:
12 *     This is a wm97xx extended touch driver to capture touch
13 *     data in a continuous manner on the Intel XScale architecture
14 *
15 *  Features:
16 *       - codecs supported:- WM9705, WM9712, WM9713
17 *       - processors supported:- Intel XScale PXA25x, PXA26x, PXA27x
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/consumer.h>
25#include <linux/irq.h>
26#include <linux/interrupt.h>
27#include <linux/io.h>
28#include <linux/soc/pxa/cpu.h>
29#include <linux/wm97xx.h>
30
31#include <sound/pxa2xx-lib.h>
32
33#include <asm/mach-types.h>
34
35struct continuous {
36	u16 id;    /* codec id */
37	u8 code;   /* continuous code */
38	u8 reads;  /* number of coord reads per read cycle */
39	u32 speed; /* number of coords per second */
40};
41
42#define WM_READS(sp) ((sp / HZ) + 1)
43
44static const struct continuous cinfo[] = {
45	{ WM9705_ID2, 0, WM_READS(94),  94  },
46	{ WM9705_ID2, 1, WM_READS(188), 188 },
47	{ WM9705_ID2, 2, WM_READS(375), 375 },
48	{ WM9705_ID2, 3, WM_READS(750), 750 },
49	{ WM9712_ID2, 0, WM_READS(94),  94  },
50	{ WM9712_ID2, 1, WM_READS(188), 188 },
51	{ WM9712_ID2, 2, WM_READS(375), 375 },
52	{ WM9712_ID2, 3, WM_READS(750), 750 },
53	{ WM9713_ID2, 0, WM_READS(94),  94  },
54	{ WM9713_ID2, 1, WM_READS(120), 120 },
55	{ WM9713_ID2, 2, WM_READS(154), 154 },
56	{ WM9713_ID2, 3, WM_READS(188), 188 },
57};
58
59/* continuous speed index */
60static int sp_idx;
61static struct gpio_desc *gpiod_irq;
62
63/*
64 * Pen sampling frequency (Hz) in continuous mode.
65 */
66static int cont_rate = 200;
67module_param(cont_rate, int, 0);
68MODULE_PARM_DESC(cont_rate, "Sampling rate in continuous mode (Hz)");
69
70/*
71 * Pen down detection.
72 *
73 * This driver can either poll or use an interrupt to indicate a pen down
74 * event. If the irq request fails then it will fall back to polling mode.
75 */
76static int pen_int;
77module_param(pen_int, int, 0);
78MODULE_PARM_DESC(pen_int, "Pen down detection (1 = interrupt, 0 = polling)");
79
80/*
81 * Pressure readback.
82 *
83 * Set to 1 to read back pen down pressure
84 */
85static int pressure;
86module_param(pressure, int, 0);
87MODULE_PARM_DESC(pressure, "Pressure readback (1 = pressure, 0 = no pressure)");
88
89/*
90 * AC97 touch data slot.
91 *
92 * Touch screen readback data ac97 slot
93 */
94static int ac97_touch_slot = 5;
95module_param(ac97_touch_slot, int, 0);
96MODULE_PARM_DESC(ac97_touch_slot, "Touch screen data slot AC97 number");
97
98
99/* flush AC97 slot 5 FIFO on pxa machines */
100static void wm97xx_acc_pen_up(struct wm97xx *wm)
101{
102	unsigned int count;
103
104	msleep(1);
105
106	if (cpu_is_pxa27x()) {
107		while (pxa2xx_ac97_read_misr() & (1 << 2))
108			pxa2xx_ac97_read_modr();
109	} else if (cpu_is_pxa3xx()) {
110		for (count = 0; count < 16; count++)
111			pxa2xx_ac97_read_modr();
112	}
113}
114
115static int wm97xx_acc_pen_down(struct wm97xx *wm)
116{
117	u16 x, y, p = 0x100 | WM97XX_ADCSEL_PRES;
118	int reads = 0;
119	static u16 last, tries;
120
121	/* When the AC97 queue has been drained we need to allow time
122	 * to buffer up samples otherwise we end up spinning polling
123	 * for samples.  The controller can't have a suitably low
124	 * threshold set to use the notifications it gives.
125	 */
126	msleep(1);
127
128	if (tries > 5) {
129		tries = 0;
130		return RC_PENUP;
131	}
132
133	x = pxa2xx_ac97_read_modr();
134	if (x == last) {
135		tries++;
136		return RC_AGAIN;
137	}
138	last = x;
139	do {
140		if (reads)
141			x = pxa2xx_ac97_read_modr();
142		y = pxa2xx_ac97_read_modr();
143		if (pressure)
144			p = pxa2xx_ac97_read_modr();
145
146		dev_dbg(wm->dev, "Raw coordinates: x=%x, y=%x, p=%x\n",
147			x, y, p);
148
149		/* are samples valid */
150		if ((x & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_X ||
151		    (y & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_Y ||
152		    (p & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_PRES)
153			goto up;
154
155		/* coordinate is good */
156		tries = 0;
157		input_report_abs(wm->input_dev, ABS_X, x & 0xfff);
158		input_report_abs(wm->input_dev, ABS_Y, y & 0xfff);
159		input_report_abs(wm->input_dev, ABS_PRESSURE, p & 0xfff);
160		input_report_key(wm->input_dev, BTN_TOUCH, (p != 0));
161		input_sync(wm->input_dev);
162		reads++;
163	} while (reads < cinfo[sp_idx].reads);
164up:
165	return RC_PENDOWN | RC_AGAIN;
166}
167
168static int wm97xx_acc_startup(struct wm97xx *wm)
169{
170	int idx = 0, ret = 0;
171
172	/* check we have a codec */
173	if (wm->ac97 == NULL)
174		return -ENODEV;
175
176	/* Go you big red fire engine */
177	for (idx = 0; idx < ARRAY_SIZE(cinfo); idx++) {
178		if (wm->id != cinfo[idx].id)
179			continue;
180		sp_idx = idx;
181		if (cont_rate <= cinfo[idx].speed)
182			break;
183	}
184	wm->acc_rate = cinfo[sp_idx].code;
185	wm->acc_slot = ac97_touch_slot;
186	dev_info(wm->dev,
187		 "mainstone accelerated touchscreen driver, %d samples/sec\n",
188		 cinfo[sp_idx].speed);
189
190	if (pen_int) {
191		gpiod_irq = gpiod_get(wm->dev, "touch", GPIOD_IN);
192		if (IS_ERR(gpiod_irq))
193			pen_int = 0;
194	}
195
196	if (pen_int) {
197		wm->pen_irq = gpiod_to_irq(gpiod_irq);
198		irq_set_irq_type(wm->pen_irq, IRQ_TYPE_EDGE_BOTH);
199	}
200
201	/* codec specific irq config */
202	if (pen_int) {
203		switch (wm->id) {
204		case WM9705_ID2:
205			break;
206		case WM9712_ID2:
207		case WM9713_ID2:
208			/* use PEN_DOWN GPIO 13 to assert IRQ on GPIO line 2 */
209			wm97xx_config_gpio(wm, WM97XX_GPIO_13, WM97XX_GPIO_IN,
210					   WM97XX_GPIO_POL_HIGH,
211					   WM97XX_GPIO_STICKY,
212					   WM97XX_GPIO_WAKE);
213			wm97xx_config_gpio(wm, WM97XX_GPIO_2, WM97XX_GPIO_OUT,
214					   WM97XX_GPIO_POL_HIGH,
215					   WM97XX_GPIO_NOTSTICKY,
216					   WM97XX_GPIO_NOWAKE);
217			break;
218		default:
219			dev_err(wm->dev,
220				"pen down irq not supported on this device\n");
221			pen_int = 0;
222			break;
223		}
224	}
225
226	return ret;
227}
228
229static void wm97xx_acc_shutdown(struct wm97xx *wm)
230{
231	/* codec specific deconfig */
232	if (pen_int) {
233		if (gpiod_irq)
234			gpiod_put(gpiod_irq);
235		wm->pen_irq = 0;
236	}
237}
238
239static struct wm97xx_mach_ops mainstone_mach_ops = {
240	.acc_enabled	= 1,
241	.acc_pen_up	= wm97xx_acc_pen_up,
242	.acc_pen_down	= wm97xx_acc_pen_down,
243	.acc_startup	= wm97xx_acc_startup,
244	.acc_shutdown	= wm97xx_acc_shutdown,
245	.irq_gpio	= WM97XX_GPIO_2,
246};
247
248static int mainstone_wm97xx_probe(struct platform_device *pdev)
249{
250	struct wm97xx *wm = platform_get_drvdata(pdev);
251
252	return wm97xx_register_mach_ops(wm, &mainstone_mach_ops);
253}
254
255static void mainstone_wm97xx_remove(struct platform_device *pdev)
256{
257	struct wm97xx *wm = platform_get_drvdata(pdev);
258
259	wm97xx_unregister_mach_ops(wm);
260}
261
262static struct platform_driver mainstone_wm97xx_driver = {
263	.probe	= mainstone_wm97xx_probe,
264	.remove_new = mainstone_wm97xx_remove,
265	.driver	= {
266		.name	= "wm97xx-touch",
267	},
268};
269module_platform_driver(mainstone_wm97xx_driver);
270
271/* Module information */
272MODULE_AUTHOR("Liam Girdwood <lrg@slimlogic.co.uk>");
273MODULE_DESCRIPTION("wm97xx continuous touch driver for mainstone");
274MODULE_LICENSE("GPL");
275