/drivers/input/touchscreen/mainstone-wm97xx.c

  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/irq.h>
 25#include <linux/interrupt.h>
 26#include <linux/wm97xx.h>
 27#include <linux/io.h>
 28#include <linux/gpio.h>
 29
 30#include <mach/regs-ac97.h>
 31
 32#include <asm/mach-types.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	{WM9705_ID2, 0, WM_READS(94), 94},
 45	{WM9705_ID2, 1, WM_READS(188), 188},
 46	{WM9705_ID2, 2, WM_READS(375), 375},
 47	{WM9705_ID2, 3, WM_READS(750), 750},
 48	{WM9712_ID2, 0, WM_READS(94), 94},
 49	{WM9712_ID2, 1, WM_READS(188), 188},
 50	{WM9712_ID2, 2, WM_READS(375), 375},
 51	{WM9712_ID2, 3, WM_READS(750), 750},
 52	{WM9713_ID2, 0, WM_READS(94), 94},
 53	{WM9713_ID2, 1, WM_READS(120), 120},
 54	{WM9713_ID2, 2, WM_READS(154), 154},
 55	{WM9713_ID2, 3, WM_READS(188), 188},
 56};
 57
 58/* continuous speed index */
 59static int sp_idx;
 60static u16 last, tries;
 61static int 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 */
100#ifdef CONFIG_PXA27x
101static void wm97xx_acc_pen_up(struct wm97xx *wm)
102{
103	schedule_timeout_uninterruptible(1);
104
105	while (MISR & (1 << 2))
106		MODR;
107}
108#else
109static void wm97xx_acc_pen_up(struct wm97xx *wm)
110{
111	unsigned int count;
112
113	schedule_timeout_uninterruptible(1);
114
115	for (count = 0; count < 16; count++)
116		MODR;
117}
118#endif
119
120static int wm97xx_acc_pen_down(struct wm97xx *wm)
121{
122	u16 x, y, p = 0x100 | WM97XX_ADCSEL_PRES;
123	int reads = 0;
124
125	/* When the AC97 queue has been drained we need to allow time
126	 * to buffer up samples otherwise we end up spinning polling
127	 * for samples.  The controller can't have a suitably low
128	 * threshold set to use the notifications it gives.
129	 */
130	schedule_timeout_uninterruptible(1);
131
132	if (tries > 5) {
133		tries = 0;
134		return RC_PENUP;
135	}
136
137	x = MODR;
138	if (x == last) {
139		tries++;
140		return RC_AGAIN;
141	}
142	last = x;
143	do {
144		if (reads)
145			x = MODR;
146		y = MODR;
147		if (pressure)
148			p = MODR;
149
150		dev_dbg(wm->dev, "Raw coordinates: x=%x, y=%x, p=%x\n",
151			x, y, p);
152
153		/* are samples valid */
154		if ((x & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_X ||
155		    (y & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_Y ||
156		    (p & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_PRES)
157			goto up;
158
159		/* coordinate is good */
160		tries = 0;
161		input_report_abs(wm->input_dev, ABS_X, x & 0xfff);
162		input_report_abs(wm->input_dev, ABS_Y, y & 0xfff);
163		input_report_abs(wm->input_dev, ABS_PRESSURE, p & 0xfff);
164		input_report_key(wm->input_dev, BTN_TOUCH, (p != 0));
165		input_sync(wm->input_dev);
166		reads++;
167	} while (reads < cinfo[sp_idx].reads);
168up:
169	return RC_PENDOWN | RC_AGAIN;
170}
171
172static int wm97xx_acc_startup(struct wm97xx *wm)
173{
174	int idx = 0, ret = 0;
175
176	/* check we have a codec */
177	if (wm->ac97 == NULL)
178		return -ENODEV;
179
180	/* Go you big red fire engine */
181	for (idx = 0; idx < ARRAY_SIZE(cinfo); idx++) {
182		if (wm->id != cinfo[idx].id)
183			continue;
184		sp_idx = idx;
185		if (cont_rate <= cinfo[idx].speed)
186			break;
187	}
188	wm->acc_rate = cinfo[sp_idx].code;
189	wm->acc_slot = ac97_touch_slot;
190	dev_info(wm->dev,
191		 "mainstone accelerated touchscreen driver, %d samples/sec\n",
192		 cinfo[sp_idx].speed);
193
194	/* IRQ driven touchscreen is used on Palm hardware */
195	if (machine_is_palmt5() || machine_is_palmtx() || machine_is_palmld()) {
196		pen_int = 1;
197		irq = 27;
198		/* There is some obscure mutant of WM9712 interbred with WM9713
199		 * used on Palm HW */
200		wm->variant = WM97xx_WM1613;
201	} else if (machine_is_mainstone() && pen_int)
202		irq = 4;
203
204	if (irq) {
205		ret = gpio_request(irq, "Touchscreen IRQ");
206		if (ret)
207			goto out;
208
209		ret = gpio_direction_input(irq);
210		if (ret) {
211			gpio_free(irq);
212			goto out;
213		}
214
215		wm->pen_irq = gpio_to_irq(irq);
216		irq_set_irq_type(wm->pen_irq, IRQ_TYPE_EDGE_BOTH);
217	} else /* pen irq not supported */
218		pen_int = 0;
219
220	/* codec specific irq config */
221	if (pen_int) {
222		switch (wm->id) {
223		case WM9705_ID2:
224			break;
225		case WM9712_ID2:
226		case WM9713_ID2:
227			/* use PEN_DOWN GPIO 13 to assert IRQ on GPIO line 2 */
228			wm97xx_config_gpio(wm, WM97XX_GPIO_13, WM97XX_GPIO_IN,
229					   WM97XX_GPIO_POL_HIGH,
230					   WM97XX_GPIO_STICKY,
231					   WM97XX_GPIO_WAKE);
232			wm97xx_config_gpio(wm, WM97XX_GPIO_2, WM97XX_GPIO_OUT,
233					   WM97XX_GPIO_POL_HIGH,
234					   WM97XX_GPIO_NOTSTICKY,
235					   WM97XX_GPIO_NOWAKE);
236			break;
237		default:
238			dev_err(wm->dev,
239				"pen down irq not supported on this device\n");
240			pen_int = 0;
241			break;
242		}
243	}
244
245out:
246	return ret;
247}
248
249static void wm97xx_acc_shutdown(struct wm97xx *wm)
250{
251	/* codec specific deconfig */
252	if (pen_int) {
253		if (irq)
254			gpio_free(irq);
255		wm->pen_irq = 0;
256	}
257}
258
259static void wm97xx_irq_enable(struct wm97xx *wm, int enable)
260{
261	if (enable)
262		enable_irq(wm->pen_irq);
263	else
264		disable_irq_nosync(wm->pen_irq);
265}
266
267static struct wm97xx_mach_ops mainstone_mach_ops = {
268	.acc_enabled = 1,
269	.acc_pen_up = wm97xx_acc_pen_up,
270	.acc_pen_down = wm97xx_acc_pen_down,
271	.acc_startup = wm97xx_acc_startup,
272	.acc_shutdown = wm97xx_acc_shutdown,
273	.irq_enable = wm97xx_irq_enable,
274	.irq_gpio = WM97XX_GPIO_2,
275};
276
277static int mainstone_wm97xx_probe(struct platform_device *pdev)
278{
279	struct wm97xx *wm = platform_get_drvdata(pdev);
280
281	return wm97xx_register_mach_ops(wm, &mainstone_mach_ops);
282}
283
284static int mainstone_wm97xx_remove(struct platform_device *pdev)
285{
286	struct wm97xx *wm = platform_get_drvdata(pdev);
287
288	wm97xx_unregister_mach_ops(wm);
289	return 0;
290}
291
292static struct platform_driver mainstone_wm97xx_driver = {
293	.probe = mainstone_wm97xx_probe,
294	.remove = mainstone_wm97xx_remove,
295	.driver = {
296		.name = "wm97xx-touch",
297	},
298};
299module_platform_driver(mainstone_wm97xx_driver);
300
301/* Module information */
302MODULE_AUTHOR("Liam Girdwood <lrg@slimlogic.co.uk>");
303MODULE_DESCRIPTION("wm97xx continuous touch driver for mainstone");
304MODULE_LICENSE("GPL");