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(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(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(wm->input_dev, ABS_X, x & 0xfff); 158 input_report_abs(wm->input_dev, ABS_Y, y & 0xfff); 159 input_report_abs(wm->input_dev, ABS_PRESSURE, p & 0xfff); 160 input_report_key(wm->input_dev, BTN_TOUCH, (p != 0)); 161 input_sync(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 /* IRQ driven touchscreen is used on Palm hardware */ 191 if (machine_is_palmt5() || machine_is_palmtx() || machine_is_palmld()) { 192 pen_int = 1; 193 /* There is some obscure mutant of WM9712 interbred with WM9713 194 * used on Palm HW */ 195 wm->variant = WM97xx_WM1613; 196 } else if (machine_is_zylonite()) { 197 pen_int = 1; 198 } 199 200 if (pen_int) { 201 gpiod_irq = gpiod_get(wm->dev, "touch", GPIOD_IN); 202 if (IS_ERR(gpiod_irq)) 203 pen_int = 0; 204 } 205 206 if (pen_int) { 207 wm->pen_irq = gpiod_to_irq(gpiod_irq); 208 irq_set_irq_type(wm->pen_irq, IRQ_TYPE_EDGE_BOTH); 209 } 210 211 /* codec specific irq config */ 212 if (pen_int) { 213 switch (wm->id) { 214 case WM9705_ID2: 215 break; 216 case WM9712_ID2: 217 case WM9713_ID2: 218 /* use PEN_DOWN GPIO 13 to assert IRQ on GPIO line 2 */ 219 wm97xx_config_gpio(wm, WM97XX_GPIO_13, WM97XX_GPIO_IN, 220 WM97XX_GPIO_POL_HIGH, 221 WM97XX_GPIO_STICKY, 222 WM97XX_GPIO_WAKE); 223 wm97xx_config_gpio(wm, WM97XX_GPIO_2, WM97XX_GPIO_OUT, 224 WM97XX_GPIO_POL_HIGH, 225 WM97XX_GPIO_NOTSTICKY, 226 WM97XX_GPIO_NOWAKE); 227 break; 228 default: 229 dev_err(wm->dev, 230 "pen down irq not supported on this device\n"); 231 pen_int = 0; 232 break; 233 } 234 } 235 236 return ret; 237 } 238 239 static void wm97xx_acc_shutdown(struct wm97xx *wm) 240 { 241 /* codec specific deconfig */ 242 if (pen_int) { 243 if (gpiod_irq) 244 gpiod_put(gpiod_irq); 245 wm->pen_irq = 0; 246 } 247 } 248 249 static struct wm97xx_mach_ops mainstone_mach_ops = { 250 .acc_enabled = 1, 251 .acc_pen_up = wm97xx_acc_pen_up, 252 .acc_pen_down = wm97xx_acc_pen_down, 253 .acc_startup = wm97xx_acc_startup, 254 .acc_shutdown = wm97xx_acc_shutdown, 255 .irq_gpio = WM97XX_GPIO_2, 256 }; 257 258 static int mainstone_wm97xx_probe(struct platform_device *pdev) 259 { 260 struct wm97xx *wm = platform_get_drvdata(pdev); 261 262 return wm97xx_register_mach_ops(wm, &mainstone_mach_ops); 263 } 264 265 static int mainstone_wm97xx_remove(struct platform_device *pdev) 266 { 267 struct wm97xx *wm = platform_get_drvdata(pdev); 268 269 wm97xx_unregister_mach_ops(wm); 270 271 return 0; 272 } 273 274 static struct platform_driver mainstone_wm97xx_driver = { 275 .probe = mainstone_wm97xx_probe, 276 .remove = mainstone_wm97xx_remove, 277 .driver = { 278 .name = "wm97xx-touch", 279 }, 280 }; 281 module_platform_driver(mainstone_wm97xx_driver); 282 283 /* Module information */ 284 MODULE_AUTHOR("Liam Girdwood <lrg@slimlogic.co.uk>"); 285 MODULE_DESCRIPTION("wm97xx continuous touch driver for mainstone"); 286 MODULE_LICENSE("GPL"); 287