1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * zylonite-wm97xx.c  --  Zylonite Continuous Touch screen driver
  4 *
  5 * Copyright 2004, 2007, 2008 Wolfson Microelectronics PLC.
  6 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
  7 * Parts Copyright : Ian Molton <spyro@f2s.com>
  8 *                   Andrew Zabolotny <zap@homelink.ru>
  9 *
 10 * Notes:
 11 *     This is a wm97xx extended touch driver supporting interrupt driven
 12 *     and continuous operation on Marvell Zylonite development systems
 13 *     (which have a WM9713 on board).
 14 */
 15
 16#include <linux/module.h>
 17#include <linux/moduleparam.h>
 18#include <linux/kernel.h>
 19#include <linux/delay.h>
 20#include <linux/gpio.h>
 21#include <linux/irq.h>
 22#include <linux/interrupt.h>
 23#include <linux/io.h>
 24#include <linux/wm97xx.h>
 25
 26#include <mach/hardware.h>
 27#include <mach/mfp.h>
 28#include <mach/regs-ac97.h>
 29
 30struct continuous {
 31	u16 id;    /* codec id */
 32	u8 code;   /* continuous code */
 33	u8 reads;  /* number of coord reads per read cycle */
 34	u32 speed; /* number of coords per second */
 35};
 36
 37#define WM_READS(sp) ((sp / HZ) + 1)
 38
 39static const struct continuous cinfo[] = {
 40	{ WM9713_ID2, 0, WM_READS(94),  94  },
 41	{ WM9713_ID2, 1, WM_READS(120), 120 },
 42	{ WM9713_ID2, 2, WM_READS(154), 154 },
 43	{ WM9713_ID2, 3, WM_READS(188), 188 },
 44};
 45
 46/* continuous speed index */
 47static int sp_idx;
 48
 49/*
 50 * Pen sampling frequency (Hz) in continuous mode.
 51 */
 52static int cont_rate = 200;
 53module_param(cont_rate, int, 0);
 54MODULE_PARM_DESC(cont_rate, "Sampling rate in continuous mode (Hz)");
 55
 56/*
 57 * Pressure readback.
 58 *
 59 * Set to 1 to read back pen down pressure
 60 */
 61static int pressure;
 62module_param(pressure, int, 0);
 63MODULE_PARM_DESC(pressure, "Pressure readback (1 = pressure, 0 = no pressure)");
 64
 65/*
 66 * AC97 touch data slot.
 67 *
 68 * Touch screen readback data ac97 slot
 69 */
 70static int ac97_touch_slot = 5;
 71module_param(ac97_touch_slot, int, 0);
 72MODULE_PARM_DESC(ac97_touch_slot, "Touch screen data slot AC97 number");
 73
 74
 75/* flush AC97 slot 5 FIFO machines */
 76static void wm97xx_acc_pen_up(struct wm97xx *wm)
 77{
 78	int i;
 79
 80	msleep(1);
 81
 82	for (i = 0; i < 16; i++)
 83		MODR;
 84}
 85
 86static int wm97xx_acc_pen_down(struct wm97xx *wm)
 87{
 88	u16 x, y, p = 0x100 | WM97XX_ADCSEL_PRES;
 89	int reads = 0;
 90	static u16 last, tries;
 91
 92	/* When the AC97 queue has been drained we need to allow time
 93	 * to buffer up samples otherwise we end up spinning polling
 94	 * for samples.  The controller can't have a suitably low
 95	 * threshold set to use the notifications it gives.
 96	 */
 97	msleep(1);
 98
 99	if (tries > 5) {
100		tries = 0;
101		return RC_PENUP;
102	}
103
104	x = MODR;
105	if (x == last) {
106		tries++;
107		return RC_AGAIN;
108	}
109	last = x;
110	do {
111		if (reads)
112			x = MODR;
113		y = MODR;
114		if (pressure)
115			p = MODR;
116
117		dev_dbg(wm->dev, "Raw coordinates: x=%x, y=%x, p=%x\n",
118			x, y, p);
119
120		/* are samples valid */
121		if ((x & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_X ||
122		    (y & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_Y ||
123		    (p & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_PRES)
124			goto up;
125
126		/* coordinate is good */
127		tries = 0;
128		input_report_abs(wm->input_dev, ABS_X, x & 0xfff);
129		input_report_abs(wm->input_dev, ABS_Y, y & 0xfff);
130		input_report_abs(wm->input_dev, ABS_PRESSURE, p & 0xfff);
131		input_report_key(wm->input_dev, BTN_TOUCH, (p != 0));
132		input_sync(wm->input_dev);
133		reads++;
134	} while (reads < cinfo[sp_idx].reads);
135up:
136	return RC_PENDOWN | RC_AGAIN;
137}
138
139static int wm97xx_acc_startup(struct wm97xx *wm)
140{
141	int idx;
142
143	/* check we have a codec */
144	if (wm->ac97 == NULL)
145		return -ENODEV;
146
147	/* Go you big red fire engine */
148	for (idx = 0; idx < ARRAY_SIZE(cinfo); idx++) {
149		if (wm->id != cinfo[idx].id)
150			continue;
151		sp_idx = idx;
152		if (cont_rate <= cinfo[idx].speed)
153			break;
154	}
155	wm->acc_rate = cinfo[sp_idx].code;
156	wm->acc_slot = ac97_touch_slot;
157	dev_info(wm->dev,
158		 "zylonite accelerated touchscreen driver, %d samples/sec\n",
159		 cinfo[sp_idx].speed);
160
161	return 0;
162}
163
164static void wm97xx_irq_enable(struct wm97xx *wm, int enable)
165{
166	if (enable)
167		enable_irq(wm->pen_irq);
168	else
169		disable_irq_nosync(wm->pen_irq);
170}
171
172static struct wm97xx_mach_ops zylonite_mach_ops = {
173	.acc_enabled	= 1,
174	.acc_pen_up	= wm97xx_acc_pen_up,
175	.acc_pen_down	= wm97xx_acc_pen_down,
176	.acc_startup	= wm97xx_acc_startup,
177	.irq_enable	= wm97xx_irq_enable,
178	.irq_gpio	= WM97XX_GPIO_2,
179};
180
181static int zylonite_wm97xx_probe(struct platform_device *pdev)
182{
183	struct wm97xx *wm = platform_get_drvdata(pdev);
184	int gpio_touch_irq;
185
186	if (cpu_is_pxa320())
187		gpio_touch_irq = mfp_to_gpio(MFP_PIN_GPIO15);
188	else
189		gpio_touch_irq = mfp_to_gpio(MFP_PIN_GPIO26);
190
191	wm->pen_irq = gpio_to_irq(gpio_touch_irq);
192	irq_set_irq_type(wm->pen_irq, IRQ_TYPE_EDGE_BOTH);
193
194	wm97xx_config_gpio(wm, WM97XX_GPIO_13, WM97XX_GPIO_IN,
195			   WM97XX_GPIO_POL_HIGH,
196			   WM97XX_GPIO_STICKY,
197			   WM97XX_GPIO_WAKE);
198	wm97xx_config_gpio(wm, WM97XX_GPIO_2, WM97XX_GPIO_OUT,
199			   WM97XX_GPIO_POL_HIGH,
200			   WM97XX_GPIO_NOTSTICKY,
201			   WM97XX_GPIO_NOWAKE);
202
203	return wm97xx_register_mach_ops(wm, &zylonite_mach_ops);
204}
205
206static int zylonite_wm97xx_remove(struct platform_device *pdev)
207{
208	struct wm97xx *wm = platform_get_drvdata(pdev);
209
210	wm97xx_unregister_mach_ops(wm);
211
212	return 0;
213}
214
215static struct platform_driver zylonite_wm97xx_driver = {
216	.probe	= zylonite_wm97xx_probe,
217	.remove	= zylonite_wm97xx_remove,
218	.driver	= {
219		.name	= "wm97xx-touch",
220	},
221};
222module_platform_driver(zylonite_wm97xx_driver);
223
224/* Module information */
225MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
226MODULE_DESCRIPTION("wm97xx continuous touch driver for Zylonite");
227MODULE_LICENSE("GPL");