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