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 | |
35 | struct 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 | |
44 | static 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 */ |
60 | static int sp_idx; |
61 | static struct gpio_desc *gpiod_irq; |
62 | |
63 | /* |
64 | * Pen sampling frequency (Hz) in continuous mode. |
65 | */ |
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)" ); |
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 | */ |
76 | static int pen_int; |
77 | module_param(pen_int, int, 0); |
78 | MODULE_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 | */ |
85 | static int pressure; |
86 | module_param(pressure, int, 0); |
87 | MODULE_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 | */ |
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" ); |
97 | |
98 | |
99 | /* flush AC97 slot 5 FIFO on pxa machines */ |
100 | static void wm97xx_acc_pen_up(struct wm97xx *wm) |
101 | { |
102 | unsigned int count; |
103 | |
104 | msleep(msecs: 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 | |
115 | static 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(msecs: 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(dev: wm->input_dev, ABS_X, value: x & 0xfff); |
158 | input_report_abs(dev: wm->input_dev, ABS_Y, value: y & 0xfff); |
159 | input_report_abs(dev: wm->input_dev, ABS_PRESSURE, value: p & 0xfff); |
160 | input_report_key(dev: wm->input_dev, BTN_TOUCH, value: (p != 0)); |
161 | input_sync(dev: wm->input_dev); |
162 | reads++; |
163 | } while (reads < cinfo[sp_idx].reads); |
164 | up: |
165 | return RC_PENDOWN | RC_AGAIN; |
166 | } |
167 | |
168 | static 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(dev: wm->dev, con_id: "touch" , flags: GPIOD_IN); |
192 | if (IS_ERR(ptr: gpiod_irq)) |
193 | pen_int = 0; |
194 | } |
195 | |
196 | if (pen_int) { |
197 | wm->pen_irq = gpiod_to_irq(desc: gpiod_irq); |
198 | irq_set_irq_type(irq: wm->pen_irq, type: 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, dir: WM97XX_GPIO_IN, |
210 | pol: WM97XX_GPIO_POL_HIGH, |
211 | sticky: WM97XX_GPIO_STICKY, |
212 | wake: WM97XX_GPIO_WAKE); |
213 | wm97xx_config_gpio(wm, WM97XX_GPIO_2, dir: WM97XX_GPIO_OUT, |
214 | pol: WM97XX_GPIO_POL_HIGH, |
215 | sticky: WM97XX_GPIO_NOTSTICKY, |
216 | wake: 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 | |
229 | static void wm97xx_acc_shutdown(struct wm97xx *wm) |
230 | { |
231 | /* codec specific deconfig */ |
232 | if (pen_int) { |
233 | if (gpiod_irq) |
234 | gpiod_put(desc: gpiod_irq); |
235 | wm->pen_irq = 0; |
236 | } |
237 | } |
238 | |
239 | static 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 | |
248 | static 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 | |
255 | static int 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 | return 0; |
262 | } |
263 | |
264 | static struct platform_driver mainstone_wm97xx_driver = { |
265 | .probe = mainstone_wm97xx_probe, |
266 | .remove = mainstone_wm97xx_remove, |
267 | .driver = { |
268 | .name = "wm97xx-touch" , |
269 | }, |
270 | }; |
271 | module_platform_driver(mainstone_wm97xx_driver); |
272 | |
273 | /* Module information */ |
274 | MODULE_AUTHOR("Liam Girdwood <lrg@slimlogic.co.uk>" ); |
275 | MODULE_DESCRIPTION("wm97xx continuous touch driver for mainstone" ); |
276 | MODULE_LICENSE("GPL" ); |
277 | |