1 /* 2 * mainstone-wm97xx.c -- Mainstone Continuous Touch screen driver for 3 * Wolfson WM97xx AC97 Codecs. 4 * 5 * Copyright 2004, 2007 Wolfson Microelectronics PLC. 6 * Author: Liam Girdwood <lrg@slimlogic.co.uk> 7 * Parts Copyright : Ian Molton <spyro@f2s.com> 8 * Andrew Zabolotny <zap@homelink.ru> 9 * 10 * This program is free software; you can redistribute it and/or modify it 11 * under the terms of the GNU General Public License as published by the 12 * Free Software Foundation; either version 2 of the License, or (at your 13 * option) any later version. 14 * 15 * Notes: 16 * This is a wm97xx extended touch driver to capture touch 17 * data in a continuous manner on the Intel XScale archictecture 18 * 19 * Features: 20 * - codecs supported:- WM9705, WM9712, WM9713 21 * - processors supported:- Intel XScale PXA25x, PXA26x, PXA27x 22 * 23 */ 24 25 #include <linux/module.h> 26 #include <linux/moduleparam.h> 27 #include <linux/kernel.h> 28 #include <linux/init.h> 29 #include <linux/delay.h> 30 #include <linux/irq.h> 31 #include <linux/interrupt.h> 32 #include <linux/wm97xx.h> 33 #include <linux/io.h> 34 #include <mach/regs-ac97.h> 35 36 #define VERSION "0.13" 37 38 struct continuous { 39 u16 id; /* codec id */ 40 u8 code; /* continuous code */ 41 u8 reads; /* number of coord reads per read cycle */ 42 u32 speed; /* number of coords per second */ 43 }; 44 45 #define WM_READS(sp) ((sp / HZ) + 1) 46 47 static const struct continuous cinfo[] = { 48 {WM9705_ID2, 0, WM_READS(94), 94}, 49 {WM9705_ID2, 1, WM_READS(188), 188}, 50 {WM9705_ID2, 2, WM_READS(375), 375}, 51 {WM9705_ID2, 3, WM_READS(750), 750}, 52 {WM9712_ID2, 0, WM_READS(94), 94}, 53 {WM9712_ID2, 1, WM_READS(188), 188}, 54 {WM9712_ID2, 2, WM_READS(375), 375}, 55 {WM9712_ID2, 3, WM_READS(750), 750}, 56 {WM9713_ID2, 0, WM_READS(94), 94}, 57 {WM9713_ID2, 1, WM_READS(120), 120}, 58 {WM9713_ID2, 2, WM_READS(154), 154}, 59 {WM9713_ID2, 3, WM_READS(188), 188}, 60 }; 61 62 /* continuous speed index */ 63 static int sp_idx; 64 static u16 last, tries; 65 66 /* 67 * Pen sampling frequency (Hz) in continuous mode. 68 */ 69 static int cont_rate = 200; 70 module_param(cont_rate, int, 0); 71 MODULE_PARM_DESC(cont_rate, "Sampling rate in continuous mode (Hz)"); 72 73 /* 74 * Pen down detection. 75 * 76 * This driver can either poll or use an interrupt to indicate a pen down 77 * event. If the irq request fails then it will fall back to polling mode. 78 */ 79 static int pen_int; 80 module_param(pen_int, int, 0); 81 MODULE_PARM_DESC(pen_int, "Pen down detection (1 = interrupt, 0 = polling)"); 82 83 /* 84 * Pressure readback. 85 * 86 * Set to 1 to read back pen down pressure 87 */ 88 static int pressure; 89 module_param(pressure, int, 0); 90 MODULE_PARM_DESC(pressure, "Pressure readback (1 = pressure, 0 = no pressure)"); 91 92 /* 93 * AC97 touch data slot. 94 * 95 * Touch screen readback data ac97 slot 96 */ 97 static int ac97_touch_slot = 5; 98 module_param(ac97_touch_slot, int, 0); 99 MODULE_PARM_DESC(ac97_touch_slot, "Touch screen data slot AC97 number"); 100 101 102 /* flush AC97 slot 5 FIFO on pxa machines */ 103 #ifdef CONFIG_PXA27x 104 static void wm97xx_acc_pen_up(struct wm97xx *wm) 105 { 106 schedule_timeout_uninterruptible(1); 107 108 while (MISR & (1 << 2)) 109 MODR; 110 } 111 #else 112 static void wm97xx_acc_pen_up(struct wm97xx *wm) 113 { 114 int count = 16; 115 schedule_timeout_uninterruptible(1); 116 117 while (count < 16) { 118 MODR; 119 count--; 120 } 121 } 122 #endif 123 124 static int wm97xx_acc_pen_down(struct wm97xx *wm) 125 { 126 u16 x, y, p = 0x100 | WM97XX_ADCSEL_PRES; 127 int reads = 0; 128 129 /* When the AC97 queue has been drained we need to allow time 130 * to buffer up samples otherwise we end up spinning polling 131 * for samples. The controller can't have a suitably low 132 * threashold set to use the notifications it gives. 133 */ 134 schedule_timeout_uninterruptible(1); 135 136 if (tries > 5) { 137 tries = 0; 138 return RC_PENUP; 139 } 140 141 x = MODR; 142 if (x == last) { 143 tries++; 144 return RC_AGAIN; 145 } 146 last = x; 147 do { 148 if (reads) 149 x = MODR; 150 y = MODR; 151 if (pressure) 152 p = MODR; 153 154 /* are samples valid */ 155 if ((x & WM97XX_ADCSRC_MASK) != WM97XX_ADCSEL_X || 156 (y & WM97XX_ADCSRC_MASK) != WM97XX_ADCSEL_Y || 157 (p & WM97XX_ADCSRC_MASK) != WM97XX_ADCSEL_PRES) 158 goto up; 159 160 /* coordinate is good */ 161 tries = 0; 162 input_report_abs(wm->input_dev, ABS_X, x & 0xfff); 163 input_report_abs(wm->input_dev, ABS_Y, y & 0xfff); 164 input_report_abs(wm->input_dev, ABS_PRESSURE, p & 0xfff); 165 input_report_key(wm->input_dev, BTN_TOUCH, (p != 0)); 166 input_sync(wm->input_dev); 167 reads++; 168 } while (reads < cinfo[sp_idx].reads); 169 up: 170 return RC_PENDOWN | RC_AGAIN; 171 } 172 173 static int wm97xx_acc_startup(struct wm97xx *wm) 174 { 175 int idx = 0; 176 177 /* check we have a codec */ 178 if (wm->ac97 == NULL) 179 return -ENODEV; 180 181 /* Go you big red fire engine */ 182 for (idx = 0; idx < ARRAY_SIZE(cinfo); idx++) { 183 if (wm->id != cinfo[idx].id) 184 continue; 185 sp_idx = idx; 186 if (cont_rate <= cinfo[idx].speed) 187 break; 188 } 189 wm->acc_rate = cinfo[sp_idx].code; 190 wm->acc_slot = ac97_touch_slot; 191 dev_info(wm->dev, 192 "mainstone accelerated touchscreen driver, %d samples/sec\n", 193 cinfo[sp_idx].speed); 194 195 /* codec specific irq config */ 196 if (pen_int) { 197 switch (wm->id) { 198 case WM9705_ID2: 199 wm->pen_irq = IRQ_GPIO(4); 200 set_irq_type(IRQ_GPIO(4), IRQ_TYPE_EDGE_BOTH); 201 break; 202 case WM9712_ID2: 203 case WM9713_ID2: 204 /* enable pen down interrupt */ 205 /* use PEN_DOWN GPIO 13 to assert IRQ on GPIO line 2 */ 206 wm->pen_irq = MAINSTONE_AC97_IRQ; 207 wm97xx_config_gpio(wm, WM97XX_GPIO_13, WM97XX_GPIO_IN, 208 WM97XX_GPIO_POL_HIGH, 209 WM97XX_GPIO_STICKY, 210 WM97XX_GPIO_WAKE); 211 wm97xx_config_gpio(wm, WM97XX_GPIO_2, WM97XX_GPIO_OUT, 212 WM97XX_GPIO_POL_HIGH, 213 WM97XX_GPIO_NOTSTICKY, 214 WM97XX_GPIO_NOWAKE); 215 break; 216 default: 217 dev_err(wm->dev, 218 "pen down irq not supported on this device\n"); 219 pen_int = 0; 220 break; 221 } 222 } 223 224 return 0; 225 } 226 227 static void wm97xx_acc_shutdown(struct wm97xx *wm) 228 { 229 /* codec specific deconfig */ 230 if (pen_int) { 231 switch (wm->id & 0xffff) { 232 case WM9705_ID2: 233 wm->pen_irq = 0; 234 break; 235 case WM9712_ID2: 236 case WM9713_ID2: 237 /* disable interrupt */ 238 wm->pen_irq = 0; 239 break; 240 } 241 } 242 } 243 244 static void wm97xx_irq_enable(struct wm97xx *wm, int enable) 245 { 246 if (enable) 247 enable_irq(wm->pen_irq); 248 else 249 disable_irq_nosync(wm->pen_irq); 250 } 251 252 static struct wm97xx_mach_ops mainstone_mach_ops = { 253 .acc_enabled = 1, 254 .acc_pen_up = wm97xx_acc_pen_up, 255 .acc_pen_down = wm97xx_acc_pen_down, 256 .acc_startup = wm97xx_acc_startup, 257 .acc_shutdown = wm97xx_acc_shutdown, 258 .irq_enable = wm97xx_irq_enable, 259 .irq_gpio = WM97XX_GPIO_2, 260 }; 261 262 static int mainstone_wm97xx_probe(struct platform_device *pdev) 263 { 264 struct wm97xx *wm = platform_get_drvdata(pdev); 265 266 return wm97xx_register_mach_ops(wm, &mainstone_mach_ops); 267 } 268 269 static int mainstone_wm97xx_remove(struct platform_device *pdev) 270 { 271 struct wm97xx *wm = platform_get_drvdata(pdev); 272 273 wm97xx_unregister_mach_ops(wm); 274 return 0; 275 } 276 277 static struct platform_driver mainstone_wm97xx_driver = { 278 .probe = mainstone_wm97xx_probe, 279 .remove = mainstone_wm97xx_remove, 280 .driver = { 281 .name = "wm97xx-touch", 282 }, 283 }; 284 285 static int __init mainstone_wm97xx_init(void) 286 { 287 return platform_driver_register(&mainstone_wm97xx_driver); 288 } 289 290 static void __exit mainstone_wm97xx_exit(void) 291 { 292 platform_driver_unregister(&mainstone_wm97xx_driver); 293 } 294 295 module_init(mainstone_wm97xx_init); 296 module_exit(mainstone_wm97xx_exit); 297 298 /* Module information */ 299 MODULE_AUTHOR("Liam Girdwood <lrg@slimlogic.co.uk>"); 300 MODULE_DESCRIPTION("wm97xx continuous touch driver for mainstone"); 301 MODULE_LICENSE("GPL"); 302