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 /* are samples valid */ 157 if ((x & WM97XX_ADCSRC_MASK) != WM97XX_ADCSEL_X || 158 (y & WM97XX_ADCSRC_MASK) != WM97XX_ADCSEL_Y || 159 (p & WM97XX_ADCSRC_MASK) != WM97XX_ADCSEL_PRES) 160 goto up; 161 162 /* coordinate is good */ 163 tries = 0; 164 input_report_abs(wm->input_dev, ABS_X, x & 0xfff); 165 input_report_abs(wm->input_dev, ABS_Y, y & 0xfff); 166 input_report_abs(wm->input_dev, ABS_PRESSURE, p & 0xfff); 167 input_report_key(wm->input_dev, BTN_TOUCH, (p != 0)); 168 input_sync(wm->input_dev); 169 reads++; 170 } while (reads < cinfo[sp_idx].reads); 171 up: 172 return RC_PENDOWN | RC_AGAIN; 173 } 174 175 static int wm97xx_acc_startup(struct wm97xx *wm) 176 { 177 int idx = 0, ret = 0; 178 179 /* check we have a codec */ 180 if (wm->ac97 == NULL) 181 return -ENODEV; 182 183 /* Go you big red fire engine */ 184 for (idx = 0; idx < ARRAY_SIZE(cinfo); idx++) { 185 if (wm->id != cinfo[idx].id) 186 continue; 187 sp_idx = idx; 188 if (cont_rate <= cinfo[idx].speed) 189 break; 190 } 191 wm->acc_rate = cinfo[sp_idx].code; 192 wm->acc_slot = ac97_touch_slot; 193 dev_info(wm->dev, 194 "mainstone accelerated touchscreen driver, %d samples/sec\n", 195 cinfo[sp_idx].speed); 196 197 /* IRQ driven touchscreen is used on Palm hardware */ 198 if (machine_is_palmt5() || machine_is_palmtx() || machine_is_palmld()) { 199 pen_int = 1; 200 irq = 27; 201 /* There is some obscure mutant of WM9712 interbred with WM9713 202 * used on Palm HW */ 203 wm->variant = WM97xx_WM1613; 204 } else if (machine_is_mainstone() && pen_int) 205 irq = 4; 206 207 if (irq) { 208 ret = gpio_request(irq, "Touchscreen IRQ"); 209 if (ret) 210 goto out; 211 212 ret = gpio_direction_input(irq); 213 if (ret) { 214 gpio_free(irq); 215 goto out; 216 } 217 218 wm->pen_irq = gpio_to_irq(irq); 219 set_irq_type(wm->pen_irq, IRQ_TYPE_EDGE_BOTH); 220 } else /* pen irq not supported */ 221 pen_int = 0; 222 223 /* codec specific irq config */ 224 if (pen_int) { 225 switch (wm->id) { 226 case WM9705_ID2: 227 break; 228 case WM9712_ID2: 229 case WM9713_ID2: 230 /* use PEN_DOWN GPIO 13 to assert IRQ on GPIO line 2 */ 231 wm97xx_config_gpio(wm, WM97XX_GPIO_13, WM97XX_GPIO_IN, 232 WM97XX_GPIO_POL_HIGH, 233 WM97XX_GPIO_STICKY, 234 WM97XX_GPIO_WAKE); 235 wm97xx_config_gpio(wm, WM97XX_GPIO_2, WM97XX_GPIO_OUT, 236 WM97XX_GPIO_POL_HIGH, 237 WM97XX_GPIO_NOTSTICKY, 238 WM97XX_GPIO_NOWAKE); 239 break; 240 default: 241 dev_err(wm->dev, 242 "pen down irq not supported on this device\n"); 243 pen_int = 0; 244 break; 245 } 246 } 247 248 out: 249 return ret; 250 } 251 252 static void wm97xx_acc_shutdown(struct wm97xx *wm) 253 { 254 /* codec specific deconfig */ 255 if (pen_int) { 256 if (irq) 257 gpio_free(irq); 258 wm->pen_irq = 0; 259 } 260 } 261 262 static void wm97xx_irq_enable(struct wm97xx *wm, int enable) 263 { 264 if (enable) 265 enable_irq(wm->pen_irq); 266 else 267 disable_irq_nosync(wm->pen_irq); 268 } 269 270 static struct wm97xx_mach_ops mainstone_mach_ops = { 271 .acc_enabled = 1, 272 .acc_pen_up = wm97xx_acc_pen_up, 273 .acc_pen_down = wm97xx_acc_pen_down, 274 .acc_startup = wm97xx_acc_startup, 275 .acc_shutdown = wm97xx_acc_shutdown, 276 .irq_enable = wm97xx_irq_enable, 277 .irq_gpio = WM97XX_GPIO_2, 278 }; 279 280 static int mainstone_wm97xx_probe(struct platform_device *pdev) 281 { 282 struct wm97xx *wm = platform_get_drvdata(pdev); 283 284 return wm97xx_register_mach_ops(wm, &mainstone_mach_ops); 285 } 286 287 static int mainstone_wm97xx_remove(struct platform_device *pdev) 288 { 289 struct wm97xx *wm = platform_get_drvdata(pdev); 290 291 wm97xx_unregister_mach_ops(wm); 292 return 0; 293 } 294 295 static struct platform_driver mainstone_wm97xx_driver = { 296 .probe = mainstone_wm97xx_probe, 297 .remove = mainstone_wm97xx_remove, 298 .driver = { 299 .name = "wm97xx-touch", 300 }, 301 }; 302 303 static int __init mainstone_wm97xx_init(void) 304 { 305 return platform_driver_register(&mainstone_wm97xx_driver); 306 } 307 308 static void __exit mainstone_wm97xx_exit(void) 309 { 310 platform_driver_unregister(&mainstone_wm97xx_driver); 311 } 312 313 module_init(mainstone_wm97xx_init); 314 module_exit(mainstone_wm97xx_exit); 315 316 /* Module information */ 317 MODULE_AUTHOR("Liam Girdwood <lrg@slimlogic.co.uk>"); 318 MODULE_DESCRIPTION("wm97xx continuous touch driver for mainstone"); 319 MODULE_LICENSE("GPL"); 320