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 architecture 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 <linux/gpio.h> 35 36 #include <mach/regs-ac97.h> 37 38 #include <asm/mach-types.h> 39 40 struct continuous { 41 u16 id; /* codec id */ 42 u8 code; /* continuous code */ 43 u8 reads; /* number of coord reads per read cycle */ 44 u32 speed; /* number of coords per second */ 45 }; 46 47 #define WM_READS(sp) ((sp / HZ) + 1) 48 49 static const struct continuous cinfo[] = { 50 {WM9705_ID2, 0, WM_READS(94), 94}, 51 {WM9705_ID2, 1, WM_READS(188), 188}, 52 {WM9705_ID2, 2, WM_READS(375), 375}, 53 {WM9705_ID2, 3, WM_READS(750), 750}, 54 {WM9712_ID2, 0, WM_READS(94), 94}, 55 {WM9712_ID2, 1, WM_READS(188), 188}, 56 {WM9712_ID2, 2, WM_READS(375), 375}, 57 {WM9712_ID2, 3, WM_READS(750), 750}, 58 {WM9713_ID2, 0, WM_READS(94), 94}, 59 {WM9713_ID2, 1, WM_READS(120), 120}, 60 {WM9713_ID2, 2, WM_READS(154), 154}, 61 {WM9713_ID2, 3, WM_READS(188), 188}, 62 }; 63 64 /* continuous speed index */ 65 static int sp_idx; 66 static u16 last, tries; 67 static int irq; 68 69 /* 70 * Pen sampling frequency (Hz) in continuous mode. 71 */ 72 static int cont_rate = 200; 73 module_param(cont_rate, int, 0); 74 MODULE_PARM_DESC(cont_rate, "Sampling rate in continuous mode (Hz)"); 75 76 /* 77 * Pen down detection. 78 * 79 * This driver can either poll or use an interrupt to indicate a pen down 80 * event. If the irq request fails then it will fall back to polling mode. 81 */ 82 static int pen_int; 83 module_param(pen_int, int, 0); 84 MODULE_PARM_DESC(pen_int, "Pen down detection (1 = interrupt, 0 = polling)"); 85 86 /* 87 * Pressure readback. 88 * 89 * Set to 1 to read back pen down pressure 90 */ 91 static int pressure; 92 module_param(pressure, int, 0); 93 MODULE_PARM_DESC(pressure, "Pressure readback (1 = pressure, 0 = no pressure)"); 94 95 /* 96 * AC97 touch data slot. 97 * 98 * Touch screen readback data ac97 slot 99 */ 100 static int ac97_touch_slot = 5; 101 module_param(ac97_touch_slot, int, 0); 102 MODULE_PARM_DESC(ac97_touch_slot, "Touch screen data slot AC97 number"); 103 104 105 /* flush AC97 slot 5 FIFO on pxa machines */ 106 #ifdef CONFIG_PXA27x 107 static void wm97xx_acc_pen_up(struct wm97xx *wm) 108 { 109 schedule_timeout_uninterruptible(1); 110 111 while (MISR & (1 << 2)) 112 MODR; 113 } 114 #else 115 static void wm97xx_acc_pen_up(struct wm97xx *wm) 116 { 117 unsigned int count; 118 119 schedule_timeout_uninterruptible(1); 120 121 for (count = 0; count < 16; count++) 122 MODR; 123 } 124 #endif 125 126 static int wm97xx_acc_pen_down(struct wm97xx *wm) 127 { 128 u16 x, y, p = 0x100 | WM97XX_ADCSEL_PRES; 129 int reads = 0; 130 131 /* When the AC97 queue has been drained we need to allow time 132 * to buffer up samples otherwise we end up spinning polling 133 * for samples. The controller can't have a suitably low 134 * threshold set to use the notifications it gives. 135 */ 136 schedule_timeout_uninterruptible(1); 137 138 if (tries > 5) { 139 tries = 0; 140 return RC_PENUP; 141 } 142 143 x = MODR; 144 if (x == last) { 145 tries++; 146 return RC_AGAIN; 147 } 148 last = x; 149 do { 150 if (reads) 151 x = MODR; 152 y = MODR; 153 if (pressure) 154 p = MODR; 155 156 dev_dbg(wm->dev, "Raw coordinates: x=%x, y=%x, p=%x\n", 157 x, y, p); 158 159 /* are samples valid */ 160 if ((x & WM97XX_ADCSRC_MASK) != WM97XX_ADCSEL_X || 161 (y & WM97XX_ADCSRC_MASK) != WM97XX_ADCSEL_Y || 162 (p & WM97XX_ADCSRC_MASK) != WM97XX_ADCSEL_PRES) 163 goto up; 164 165 /* coordinate is good */ 166 tries = 0; 167 input_report_abs(wm->input_dev, ABS_X, x & 0xfff); 168 input_report_abs(wm->input_dev, ABS_Y, y & 0xfff); 169 input_report_abs(wm->input_dev, ABS_PRESSURE, p & 0xfff); 170 input_report_key(wm->input_dev, BTN_TOUCH, (p != 0)); 171 input_sync(wm->input_dev); 172 reads++; 173 } while (reads < cinfo[sp_idx].reads); 174 up: 175 return RC_PENDOWN | RC_AGAIN; 176 } 177 178 static int wm97xx_acc_startup(struct wm97xx *wm) 179 { 180 int idx = 0, ret = 0; 181 182 /* check we have a codec */ 183 if (wm->ac97 == NULL) 184 return -ENODEV; 185 186 /* Go you big red fire engine */ 187 for (idx = 0; idx < ARRAY_SIZE(cinfo); idx++) { 188 if (wm->id != cinfo[idx].id) 189 continue; 190 sp_idx = idx; 191 if (cont_rate <= cinfo[idx].speed) 192 break; 193 } 194 wm->acc_rate = cinfo[sp_idx].code; 195 wm->acc_slot = ac97_touch_slot; 196 dev_info(wm->dev, 197 "mainstone accelerated touchscreen driver, %d samples/sec\n", 198 cinfo[sp_idx].speed); 199 200 /* IRQ driven touchscreen is used on Palm hardware */ 201 if (machine_is_palmt5() || machine_is_palmtx() || machine_is_palmld()) { 202 pen_int = 1; 203 irq = 27; 204 /* There is some obscure mutant of WM9712 interbred with WM9713 205 * used on Palm HW */ 206 wm->variant = WM97xx_WM1613; 207 } else if (machine_is_mainstone() && pen_int) 208 irq = 4; 209 210 if (irq) { 211 ret = gpio_request(irq, "Touchscreen IRQ"); 212 if (ret) 213 goto out; 214 215 ret = gpio_direction_input(irq); 216 if (ret) { 217 gpio_free(irq); 218 goto out; 219 } 220 221 wm->pen_irq = gpio_to_irq(irq); 222 set_irq_type(wm->pen_irq, IRQ_TYPE_EDGE_BOTH); 223 } else /* pen irq not supported */ 224 pen_int = 0; 225 226 /* codec specific irq config */ 227 if (pen_int) { 228 switch (wm->id) { 229 case WM9705_ID2: 230 break; 231 case WM9712_ID2: 232 case WM9713_ID2: 233 /* use PEN_DOWN GPIO 13 to assert IRQ on GPIO line 2 */ 234 wm97xx_config_gpio(wm, WM97XX_GPIO_13, WM97XX_GPIO_IN, 235 WM97XX_GPIO_POL_HIGH, 236 WM97XX_GPIO_STICKY, 237 WM97XX_GPIO_WAKE); 238 wm97xx_config_gpio(wm, WM97XX_GPIO_2, WM97XX_GPIO_OUT, 239 WM97XX_GPIO_POL_HIGH, 240 WM97XX_GPIO_NOTSTICKY, 241 WM97XX_GPIO_NOWAKE); 242 break; 243 default: 244 dev_err(wm->dev, 245 "pen down irq not supported on this device\n"); 246 pen_int = 0; 247 break; 248 } 249 } 250 251 out: 252 return ret; 253 } 254 255 static void wm97xx_acc_shutdown(struct wm97xx *wm) 256 { 257 /* codec specific deconfig */ 258 if (pen_int) { 259 if (irq) 260 gpio_free(irq); 261 wm->pen_irq = 0; 262 } 263 } 264 265 static void wm97xx_irq_enable(struct wm97xx *wm, int enable) 266 { 267 if (enable) 268 enable_irq(wm->pen_irq); 269 else 270 disable_irq_nosync(wm->pen_irq); 271 } 272 273 static struct wm97xx_mach_ops mainstone_mach_ops = { 274 .acc_enabled = 1, 275 .acc_pen_up = wm97xx_acc_pen_up, 276 .acc_pen_down = wm97xx_acc_pen_down, 277 .acc_startup = wm97xx_acc_startup, 278 .acc_shutdown = wm97xx_acc_shutdown, 279 .irq_enable = wm97xx_irq_enable, 280 .irq_gpio = WM97XX_GPIO_2, 281 }; 282 283 static int mainstone_wm97xx_probe(struct platform_device *pdev) 284 { 285 struct wm97xx *wm = platform_get_drvdata(pdev); 286 287 return wm97xx_register_mach_ops(wm, &mainstone_mach_ops); 288 } 289 290 static int mainstone_wm97xx_remove(struct platform_device *pdev) 291 { 292 struct wm97xx *wm = platform_get_drvdata(pdev); 293 294 wm97xx_unregister_mach_ops(wm); 295 return 0; 296 } 297 298 static struct platform_driver mainstone_wm97xx_driver = { 299 .probe = mainstone_wm97xx_probe, 300 .remove = mainstone_wm97xx_remove, 301 .driver = { 302 .name = "wm97xx-touch", 303 }, 304 }; 305 306 static int __init mainstone_wm97xx_init(void) 307 { 308 return platform_driver_register(&mainstone_wm97xx_driver); 309 } 310 311 static void __exit mainstone_wm97xx_exit(void) 312 { 313 platform_driver_unregister(&mainstone_wm97xx_driver); 314 } 315 316 module_init(mainstone_wm97xx_init); 317 module_exit(mainstone_wm97xx_exit); 318 319 /* Module information */ 320 MODULE_AUTHOR("Liam Girdwood <lrg@slimlogic.co.uk>"); 321 MODULE_DESCRIPTION("wm97xx continuous touch driver for mainstone"); 322 MODULE_LICENSE("GPL"); 323