1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * mainstone-wm97xx.c -- Mainstone Continuous Touch screen driver for
4 * Wolfson WM97xx AC97 Codecs.
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>
12 * This is a wm97xx extended touch driver to capture touch
13 * data in a continuous manner on the Intel XScale architecture
16 * - codecs supported:- WM9705, WM9712, WM9713
17 * - processors supported:- Intel XScale PXA25x, PXA26x, PXA27x
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>
28 #include <linux/gpio.h>
30 #include <mach/regs-ac97.h>
32 #include <asm/mach-types.h>
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 */
41 #define WM_READS(sp) ((sp / HZ) + 1)
43 static 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},
58 /* continuous speed index */
60 static u16 last, tries;
64 * Pen sampling frequency (Hz) in continuous mode.
66 static int cont_rate = 200;
67 module_param(cont_rate, int, 0);
68 MODULE_PARM_DESC(cont_rate, "Sampling rate in continuous mode (Hz)");
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.
77 module_param(pen_int, int, 0);
78 MODULE_PARM_DESC(pen_int, "Pen down detection (1 = interrupt, 0 = polling)");
83 * Set to 1 to read back pen down pressure
86 module_param(pressure, int, 0);
87 MODULE_PARM_DESC(pressure, "Pressure readback (1 = pressure, 0 = no pressure)");
90 * AC97 touch data slot.
92 * Touch screen readback data ac97 slot
94 static int ac97_touch_slot = 5;
95 module_param(ac97_touch_slot, int, 0);
96 MODULE_PARM_DESC(ac97_touch_slot, "Touch screen data slot AC97 number");
99 /* flush AC97 slot 5 FIFO on pxa machines */
101 static void wm97xx_acc_pen_up(struct wm97xx *wm)
103 schedule_timeout_uninterruptible(1);
105 while (MISR & (1 << 2))
109 static void wm97xx_acc_pen_up(struct wm97xx *wm)
113 schedule_timeout_uninterruptible(1);
115 for (count = 0; count < 16; count++)
120 static int wm97xx_acc_pen_down(struct wm97xx *wm)
122 u16 x, y, p = 0x100 | WM97XX_ADCSEL_PRES;
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.
130 schedule_timeout_uninterruptible(1);
150 dev_dbg(wm->dev, "Raw coordinates: x=%x, y=%x, p=%x\n",
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)
159 /* coordinate is good */
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);
167 } while (reads < cinfo[sp_idx].reads);
169 return RC_PENDOWN | RC_AGAIN;
172 static int wm97xx_acc_startup(struct wm97xx *wm)
174 int idx = 0, ret = 0;
176 /* check we have a codec */
177 if (wm->ac97 == NULL)
180 /* Go you big red fire engine */
181 for (idx = 0; idx < ARRAY_SIZE(cinfo); idx++) {
182 if (wm->id != cinfo[idx].id)
185 if (cont_rate <= cinfo[idx].speed)
188 wm->acc_rate = cinfo[sp_idx].code;
189 wm->acc_slot = ac97_touch_slot;
191 "mainstone accelerated touchscreen driver, %d samples/sec\n",
192 cinfo[sp_idx].speed);
194 /* IRQ driven touchscreen is used on Palm hardware */
195 if (machine_is_palmt5() || machine_is_palmtx() || machine_is_palmld()) {
198 /* There is some obscure mutant of WM9712 interbred with WM9713
200 wm->variant = WM97xx_WM1613;
201 } else if (machine_is_mainstone() && pen_int)
205 ret = gpio_request(irq, "Touchscreen IRQ");
209 ret = gpio_direction_input(irq);
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 */
220 /* codec specific irq config */
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,
232 wm97xx_config_gpio(wm, WM97XX_GPIO_2, WM97XX_GPIO_OUT,
233 WM97XX_GPIO_POL_HIGH,
234 WM97XX_GPIO_NOTSTICKY,
239 "pen down irq not supported on this device\n");
249 static void wm97xx_acc_shutdown(struct wm97xx *wm)
251 /* codec specific deconfig */
259 static void wm97xx_irq_enable(struct wm97xx *wm, int enable)
262 enable_irq(wm->pen_irq);
264 disable_irq_nosync(wm->pen_irq);
267 static struct wm97xx_mach_ops mainstone_mach_ops = {
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,
277 static int mainstone_wm97xx_probe(struct platform_device *pdev)
279 struct wm97xx *wm = platform_get_drvdata(pdev);
281 return wm97xx_register_mach_ops(wm, &mainstone_mach_ops);
284 static int mainstone_wm97xx_remove(struct platform_device *pdev)
286 struct wm97xx *wm = platform_get_drvdata(pdev);
288 wm97xx_unregister_mach_ops(wm);
292 static struct platform_driver mainstone_wm97xx_driver = {
293 .probe = mainstone_wm97xx_probe,
294 .remove = mainstone_wm97xx_remove,
296 .name = "wm97xx-touch",
299 module_platform_driver(mainstone_wm97xx_driver);
301 /* Module information */
302 MODULE_AUTHOR("Liam Girdwood <lrg@slimlogic.co.uk>");
303 MODULE_DESCRIPTION("wm97xx continuous touch driver for mainstone");
304 MODULE_LICENSE("GPL");