// SPDX-License-Identifier: GPL-2.0-or-later /* * mainstone-wm97xx.c -- Mainstone Continuous Touch screen driver for * Wolfson WM97xx AC97 Codecs. * * Copyright 2004, 2007 Wolfson Microelectronics PLC. * Author: Liam Girdwood * Parts Copyright : Ian Molton * Andrew Zabolotny * * Notes: * This is a wm97xx extended touch driver to capture touch * data in a continuous manner on the Intel XScale architecture * * Features: * - codecs supported:- WM9705, WM9712, WM9713 * - processors supported:- Intel XScale PXA25x, PXA26x, PXA27x */ #include #include #include #include #include #include #include #include #include #include #include #include struct continuous { u16 id; /* codec id */ u8 code; /* continuous code */ u8 reads; /* number of coord reads per read cycle */ u32 speed; /* number of coords per second */ }; #define WM_READS(sp) ((sp / HZ) + 1) static const struct continuous cinfo[] = { { WM9705_ID2, 0, WM_READS(94), 94 }, { WM9705_ID2, 1, WM_READS(188), 188 }, { WM9705_ID2, 2, WM_READS(375), 375 }, { WM9705_ID2, 3, WM_READS(750), 750 }, { WM9712_ID2, 0, WM_READS(94), 94 }, { WM9712_ID2, 1, WM_READS(188), 188 }, { WM9712_ID2, 2, WM_READS(375), 375 }, { WM9712_ID2, 3, WM_READS(750), 750 }, { WM9713_ID2, 0, WM_READS(94), 94 }, { WM9713_ID2, 1, WM_READS(120), 120 }, { WM9713_ID2, 2, WM_READS(154), 154 }, { WM9713_ID2, 3, WM_READS(188), 188 }, }; /* continuous speed index */ static int sp_idx; static struct gpio_desc *gpiod_irq; /* * Pen sampling frequency (Hz) in continuous mode. */ static int cont_rate = 200; module_param(cont_rate, int, 0); MODULE_PARM_DESC(cont_rate, "Sampling rate in continuous mode (Hz)"); /* * Pen down detection. * * This driver can either poll or use an interrupt to indicate a pen down * event. If the irq request fails then it will fall back to polling mode. */ static int pen_int; module_param(pen_int, int, 0); MODULE_PARM_DESC(pen_int, "Pen down detection (1 = interrupt, 0 = polling)"); /* * Pressure readback. * * Set to 1 to read back pen down pressure */ static int pressure; module_param(pressure, int, 0); MODULE_PARM_DESC(pressure, "Pressure readback (1 = pressure, 0 = no pressure)"); /* * AC97 touch data slot. * * Touch screen readback data ac97 slot */ static int ac97_touch_slot = 5; module_param(ac97_touch_slot, int, 0); MODULE_PARM_DESC(ac97_touch_slot, "Touch screen data slot AC97 number"); /* flush AC97 slot 5 FIFO on pxa machines */ static void wm97xx_acc_pen_up(struct wm97xx *wm) { unsigned int count; msleep(1); if (cpu_is_pxa27x()) { while (pxa2xx_ac97_read_misr() & (1 << 2)) pxa2xx_ac97_read_modr(); } else if (cpu_is_pxa3xx()) { for (count = 0; count < 16; count++) pxa2xx_ac97_read_modr(); } } static int wm97xx_acc_pen_down(struct wm97xx *wm) { u16 x, y, p = 0x100 | WM97XX_ADCSEL_PRES; int reads = 0; static u16 last, tries; /* When the AC97 queue has been drained we need to allow time * to buffer up samples otherwise we end up spinning polling * for samples. The controller can't have a suitably low * threshold set to use the notifications it gives. */ msleep(1); if (tries > 5) { tries = 0; return RC_PENUP; } x = pxa2xx_ac97_read_modr(); if (x == last) { tries++; return RC_AGAIN; } last = x; do { if (reads) x = pxa2xx_ac97_read_modr(); y = pxa2xx_ac97_read_modr(); if (pressure) p = pxa2xx_ac97_read_modr(); dev_dbg(wm->dev, "Raw coordinates: x=%x, y=%x, p=%x\n", x, y, p); /* are samples valid */ if ((x & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_X || (y & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_Y || (p & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_PRES) goto up; /* coordinate is good */ tries = 0; input_report_abs(wm->input_dev, ABS_X, x & 0xfff); input_report_abs(wm->input_dev, ABS_Y, y & 0xfff); input_report_abs(wm->input_dev, ABS_PRESSURE, p & 0xfff); input_report_key(wm->input_dev, BTN_TOUCH, (p != 0)); input_sync(wm->input_dev); reads++; } while (reads < cinfo[sp_idx].reads); up: return RC_PENDOWN | RC_AGAIN; } static int wm97xx_acc_startup(struct wm97xx *wm) { int idx = 0, ret = 0; /* check we have a codec */ if (wm->ac97 == NULL) return -ENODEV; /* Go you big red fire engine */ for (idx = 0; idx < ARRAY_SIZE(cinfo); idx++) { if (wm->id != cinfo[idx].id) continue; sp_idx = idx; if (cont_rate <= cinfo[idx].speed) break; } wm->acc_rate = cinfo[sp_idx].code; wm->acc_slot = ac97_touch_slot; dev_info(wm->dev, "mainstone accelerated touchscreen driver, %d samples/sec\n", cinfo[sp_idx].speed); if (pen_int) { gpiod_irq = gpiod_get(wm->dev, "touch", GPIOD_IN); if (IS_ERR(gpiod_irq)) pen_int = 0; } if (pen_int) { wm->pen_irq = gpiod_to_irq(gpiod_irq); irq_set_irq_type(wm->pen_irq, IRQ_TYPE_EDGE_BOTH); } /* codec specific irq config */ if (pen_int) { switch (wm->id) { case WM9705_ID2: break; case WM9712_ID2: case WM9713_ID2: /* use PEN_DOWN GPIO 13 to assert IRQ on GPIO line 2 */ wm97xx_config_gpio(wm, WM97XX_GPIO_13, WM97XX_GPIO_IN, WM97XX_GPIO_POL_HIGH, WM97XX_GPIO_STICKY, WM97XX_GPIO_WAKE); wm97xx_config_gpio(wm, WM97XX_GPIO_2, WM97XX_GPIO_OUT, WM97XX_GPIO_POL_HIGH, WM97XX_GPIO_NOTSTICKY, WM97XX_GPIO_NOWAKE); break; default: dev_err(wm->dev, "pen down irq not supported on this device\n"); pen_int = 0; break; } } return ret; } static void wm97xx_acc_shutdown(struct wm97xx *wm) { /* codec specific deconfig */ if (pen_int) { if (gpiod_irq) gpiod_put(gpiod_irq); wm->pen_irq = 0; } } static struct wm97xx_mach_ops mainstone_mach_ops = { .acc_enabled = 1, .acc_pen_up = wm97xx_acc_pen_up, .acc_pen_down = wm97xx_acc_pen_down, .acc_startup = wm97xx_acc_startup, .acc_shutdown = wm97xx_acc_shutdown, .irq_gpio = WM97XX_GPIO_2, }; static int mainstone_wm97xx_probe(struct platform_device *pdev) { struct wm97xx *wm = platform_get_drvdata(pdev); return wm97xx_register_mach_ops(wm, &mainstone_mach_ops); } static void mainstone_wm97xx_remove(struct platform_device *pdev) { struct wm97xx *wm = platform_get_drvdata(pdev); wm97xx_unregister_mach_ops(wm); } static struct platform_driver mainstone_wm97xx_driver = { .probe = mainstone_wm97xx_probe, .remove = mainstone_wm97xx_remove, .driver = { .name = "wm97xx-touch", }, }; module_platform_driver(mainstone_wm97xx_driver); /* Module information */ MODULE_AUTHOR("Liam Girdwood "); MODULE_DESCRIPTION("wm97xx continuous touch driver for mainstone"); MODULE_LICENSE("GPL");