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/irq.h> 25 #include <linux/interrupt.h> 26 #include <linux/wm97xx.h> 27 #include <linux/io.h> 28 #include <linux/gpio.h> 29 30 #include <mach/regs-ac97.h> 31 32 #include <asm/mach-types.h> 33 34 struct continuous { 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 */ 39 }; 40 41 #define WM_READS(sp) ((sp / HZ) + 1) 42 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}, 56 }; 57 58 /* continuous speed index */ 59 static int sp_idx; 60 static u16 last, tries; 61 static int 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 #ifdef CONFIG_PXA27x 101 static void wm97xx_acc_pen_up(struct wm97xx *wm) 102 { 103 schedule_timeout_uninterruptible(1); 104 105 while (MISR & (1 << 2)) 106 MODR; 107 } 108 #else 109 static void wm97xx_acc_pen_up(struct wm97xx *wm) 110 { 111 unsigned int count; 112 113 schedule_timeout_uninterruptible(1); 114 115 for (count = 0; count < 16; count++) 116 MODR; 117 } 118 #endif 119 120 static int wm97xx_acc_pen_down(struct wm97xx *wm) 121 { 122 u16 x, y, p = 0x100 | WM97XX_ADCSEL_PRES; 123 int reads = 0; 124 125 /* 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. 129 */ 130 schedule_timeout_uninterruptible(1); 131 132 if (tries > 5) { 133 tries = 0; 134 return RC_PENUP; 135 } 136 137 x = MODR; 138 if (x == last) { 139 tries++; 140 return RC_AGAIN; 141 } 142 last = x; 143 do { 144 if (reads) 145 x = MODR; 146 y = MODR; 147 if (pressure) 148 p = MODR; 149 150 dev_dbg(wm->dev, "Raw coordinates: x=%x, y=%x, p=%x\n", 151 x, y, p); 152 153 /* 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) 157 goto up; 158 159 /* coordinate is good */ 160 tries = 0; 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); 166 reads++; 167 } while (reads < cinfo[sp_idx].reads); 168 up: 169 return RC_PENDOWN | RC_AGAIN; 170 } 171 172 static int wm97xx_acc_startup(struct wm97xx *wm) 173 { 174 int idx = 0, ret = 0; 175 176 /* check we have a codec */ 177 if (wm->ac97 == NULL) 178 return -ENODEV; 179 180 /* Go you big red fire engine */ 181 for (idx = 0; idx < ARRAY_SIZE(cinfo); idx++) { 182 if (wm->id != cinfo[idx].id) 183 continue; 184 sp_idx = idx; 185 if (cont_rate <= cinfo[idx].speed) 186 break; 187 } 188 wm->acc_rate = cinfo[sp_idx].code; 189 wm->acc_slot = ac97_touch_slot; 190 dev_info(wm->dev, 191 "mainstone accelerated touchscreen driver, %d samples/sec\n", 192 cinfo[sp_idx].speed); 193 194 /* IRQ driven touchscreen is used on Palm hardware */ 195 if (machine_is_palmt5() || machine_is_palmtx() || machine_is_palmld()) { 196 pen_int = 1; 197 irq = 27; 198 /* There is some obscure mutant of WM9712 interbred with WM9713 199 * used on Palm HW */ 200 wm->variant = WM97xx_WM1613; 201 } else if (machine_is_mainstone() && pen_int) 202 irq = 4; 203 204 if (irq) { 205 ret = gpio_request(irq, "Touchscreen IRQ"); 206 if (ret) 207 goto out; 208 209 ret = gpio_direction_input(irq); 210 if (ret) { 211 gpio_free(irq); 212 goto out; 213 } 214 215 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 */ 218 pen_int = 0; 219 220 /* codec specific irq config */ 221 if (pen_int) { 222 switch (wm->id) { 223 case WM9705_ID2: 224 break; 225 case WM9712_ID2: 226 case WM9713_ID2: 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, 230 WM97XX_GPIO_STICKY, 231 WM97XX_GPIO_WAKE); 232 wm97xx_config_gpio(wm, WM97XX_GPIO_2, WM97XX_GPIO_OUT, 233 WM97XX_GPIO_POL_HIGH, 234 WM97XX_GPIO_NOTSTICKY, 235 WM97XX_GPIO_NOWAKE); 236 break; 237 default: 238 dev_err(wm->dev, 239 "pen down irq not supported on this device\n"); 240 pen_int = 0; 241 break; 242 } 243 } 244 245 out: 246 return ret; 247 } 248 249 static void wm97xx_acc_shutdown(struct wm97xx *wm) 250 { 251 /* codec specific deconfig */ 252 if (pen_int) { 253 if (irq) 254 gpio_free(irq); 255 wm->pen_irq = 0; 256 } 257 } 258 259 static void wm97xx_irq_enable(struct wm97xx *wm, int enable) 260 { 261 if (enable) 262 enable_irq(wm->pen_irq); 263 else 264 disable_irq_nosync(wm->pen_irq); 265 } 266 267 static struct wm97xx_mach_ops mainstone_mach_ops = { 268 .acc_enabled = 1, 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, 275 }; 276 277 static int mainstone_wm97xx_probe(struct platform_device *pdev) 278 { 279 struct wm97xx *wm = platform_get_drvdata(pdev); 280 281 return wm97xx_register_mach_ops(wm, &mainstone_mach_ops); 282 } 283 284 static int mainstone_wm97xx_remove(struct platform_device *pdev) 285 { 286 struct wm97xx *wm = platform_get_drvdata(pdev); 287 288 wm97xx_unregister_mach_ops(wm); 289 return 0; 290 } 291 292 static struct platform_driver mainstone_wm97xx_driver = { 293 .probe = mainstone_wm97xx_probe, 294 .remove = mainstone_wm97xx_remove, 295 .driver = { 296 .name = "wm97xx-touch", 297 }, 298 }; 299 module_platform_driver(mainstone_wm97xx_driver); 300 301 /* Module information */ 302 MODULE_AUTHOR("Liam Girdwood <lrg@slimlogic.co.uk>"); 303 MODULE_DESCRIPTION("wm97xx continuous touch driver for mainstone"); 304 MODULE_LICENSE("GPL"); 305