/* * wm97xx-core.c -- Touch screen driver core for Wolfson WM9705, WM9712 * and WM9713 AC97 Codecs. * * Copyright 2003, 2004, 2005, 2006, 2007, 2008 Wolfson Microelectronics PLC. * Author: Liam Girdwood * Parts Copyright : Ian Molton * Andrew Zabolotny * Russell King * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the * Free Software Foundation; either version 2 of the License, or (at your * option) any later version. * * Notes: * * Features: * - supports WM9705, WM9712, WM9713 * - polling mode * - continuous mode (arch-dependent) * - adjustable rpu/dpp settings * - adjustable pressure current * - adjustable sample settle delay * - 4 and 5 wire touchscreens (5 wire is WM9712 only) * - pen down detection * - battery monitor * - sample AUX adcs * - power management * - codec GPIO * - codec event notification * Todo * - Support for async sampling control for noisy LCDs. * */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define TS_NAME "wm97xx" #define WM_CORE_VERSION "1.00" #define DEFAULT_PRESSURE 0xb0c0 /* * Touchscreen absolute values * * These parameters are used to help the input layer discard out of * range readings and reduce jitter etc. * * o min, max:- indicate the min and max values your touch screen returns * o fuzz:- use a higher number to reduce jitter * * The default values correspond to Mainstone II in QVGA mode * * Please read * Documentation/input/input-programming.txt for more details. */ static int abs_x[3] = {350, 3900, 5}; module_param_array(abs_x, int, NULL, 0); MODULE_PARM_DESC(abs_x, "Touchscreen absolute X min, max, fuzz"); static int abs_y[3] = {320, 3750, 40}; module_param_array(abs_y, int, NULL, 0); MODULE_PARM_DESC(abs_y, "Touchscreen absolute Y min, max, fuzz"); static int abs_p[3] = {0, 150, 4}; module_param_array(abs_p, int, NULL, 0); MODULE_PARM_DESC(abs_p, "Touchscreen absolute Pressure min, max, fuzz"); /* * wm97xx IO access, all IO locking done by AC97 layer */ int wm97xx_reg_read(struct wm97xx *wm, u16 reg) { if (wm->ac97) return wm->ac97->bus->ops->read(wm->ac97, reg); else return -1; } EXPORT_SYMBOL_GPL(wm97xx_reg_read); void wm97xx_reg_write(struct wm97xx *wm, u16 reg, u16 val) { /* cache digitiser registers */ if (reg >= AC97_WM9713_DIG1 && reg <= AC97_WM9713_DIG3) wm->dig[(reg - AC97_WM9713_DIG1) >> 1] = val; /* cache gpio regs */ if (reg >= AC97_GPIO_CFG && reg <= AC97_MISC_AFE) wm->gpio[(reg - AC97_GPIO_CFG) >> 1] = val; /* wm9713 irq reg */ if (reg == 0x5a) wm->misc = val; if (wm->ac97) wm->ac97->bus->ops->write(wm->ac97, reg, val); } EXPORT_SYMBOL_GPL(wm97xx_reg_write); /** * wm97xx_read_aux_adc - Read the aux adc. * @wm: wm97xx device. * @adcsel: codec ADC to be read * * Reads the selected AUX ADC. */ int wm97xx_read_aux_adc(struct wm97xx *wm, u16 adcsel) { int power_adc = 0, auxval; u16 power = 0; int rc = 0; int timeout = 0; /* get codec */ mutex_lock(&wm->codec_mutex); /* When the touchscreen is not in use, we may have to power up * the AUX ADC before we can use sample the AUX inputs-> */ if (wm->id == WM9713_ID2 && (power = wm97xx_reg_read(wm, AC97_EXTENDED_MID)) & 0x8000) { power_adc = 1; wm97xx_reg_write(wm, AC97_EXTENDED_MID, power & 0x7fff); } /* Prepare the codec for AUX reading */ wm->codec->aux_prepare(wm); /* Turn polling mode on to read AUX ADC */ wm->pen_probably_down = 1; while (rc != RC_VALID && timeout++ < 5) rc = wm->codec->poll_sample(wm, adcsel, &auxval); if (power_adc) wm97xx_reg_write(wm, AC97_EXTENDED_MID, power | 0x8000); wm->codec->dig_restore(wm); wm->pen_probably_down = 0; if (timeout >= 5) { dev_err(wm->dev, "timeout reading auxadc %d, disabling digitiser\n", adcsel); wm->codec->dig_enable(wm, false); } mutex_unlock(&wm->codec_mutex); return (rc == RC_VALID ? auxval & 0xfff : -EBUSY); } EXPORT_SYMBOL_GPL(wm97xx_read_aux_adc); /** * wm97xx_get_gpio - Get the status of a codec GPIO. * @wm: wm97xx device. * @gpio: gpio * * Get the status of a codec GPIO pin */ enum wm97xx_gpio_status wm97xx_get_gpio(struct wm97xx *wm, u32 gpio) { u16 status; enum wm97xx_gpio_status ret; mutex_lock(&wm->codec_mutex); status = wm97xx_reg_read(wm, AC97_GPIO_STATUS); if (status & gpio) ret = WM97XX_GPIO_HIGH; else ret = WM97XX_GPIO_LOW; mutex_unlock(&wm->codec_mutex); return ret; } EXPORT_SYMBOL_GPL(wm97xx_get_gpio); /** * wm97xx_set_gpio - Set the status of a codec GPIO. * @wm: wm97xx device. * @gpio: gpio * * * Set the status of a codec GPIO pin */ void wm97xx_set_gpio(struct wm97xx *wm, u32 gpio, enum wm97xx_gpio_status status) { u16 reg; mutex_lock(&wm->codec_mutex); reg = wm97xx_reg_read(wm, AC97_GPIO_STATUS); if (status == WM97XX_GPIO_HIGH) reg |= gpio; else reg &= ~gpio; if (wm->id == WM9712_ID2 && wm->variant != WM97xx_WM1613) wm97xx_reg_write(wm, AC97_GPIO_STATUS, reg << 1); else wm97xx_reg_write(wm, AC97_GPIO_STATUS, reg); mutex_unlock(&wm->codec_mutex); } EXPORT_SYMBOL_GPL(wm97xx_set_gpio); /* * Codec GPIO pin configuration, this sets pin direction, polarity, * stickyness and wake up. */ void wm97xx_config_gpio(struct wm97xx *wm, u32 gpio, enum wm97xx_gpio_dir dir, enum wm97xx_gpio_pol pol, enum wm97xx_gpio_sticky sticky, enum wm97xx_gpio_wake wake) { u16 reg; mutex_lock(&wm->codec_mutex); reg = wm97xx_reg_read(wm, AC97_GPIO_POLARITY); if (pol == WM97XX_GPIO_POL_HIGH) reg |= gpio; else reg &= ~gpio; wm97xx_reg_write(wm, AC97_GPIO_POLARITY, reg); reg = wm97xx_reg_read(wm, AC97_GPIO_STICKY); if (sticky == WM97XX_GPIO_STICKY) reg |= gpio; else reg &= ~gpio; wm97xx_reg_write(wm, AC97_GPIO_STICKY, reg); reg = wm97xx_reg_read(wm, AC97_GPIO_WAKEUP); if (wake == WM97XX_GPIO_WAKE) reg |= gpio; else reg &= ~gpio; wm97xx_reg_write(wm, AC97_GPIO_WAKEUP, reg); reg = wm97xx_reg_read(wm, AC97_GPIO_CFG); if (dir == WM97XX_GPIO_IN) reg |= gpio; else reg &= ~gpio; wm97xx_reg_write(wm, AC97_GPIO_CFG, reg); mutex_unlock(&wm->codec_mutex); } EXPORT_SYMBOL_GPL(wm97xx_config_gpio); /* * Configure the WM97XX_PRP value to use while system is suspended. * If a value other than 0 is set then WM97xx pen detection will be * left enabled in the configured mode while the system is in suspend, * the device has users and suspend has not been disabled via the * wakeup sysfs entries. * * @wm: WM97xx device to configure * @mode: WM97XX_PRP value to configure while suspended */ void wm97xx_set_suspend_mode(struct wm97xx *wm, u16 mode) { wm->suspend_mode = mode; device_init_wakeup(&wm->input_dev->dev, mode != 0); } EXPORT_SYMBOL_GPL(wm97xx_set_suspend_mode); /* * Handle a pen down interrupt. */ static void wm97xx_pen_irq_worker(struct work_struct *work) { struct wm97xx *wm = container_of(work, struct wm97xx, pen_event_work); int pen_was_down = wm->pen_is_down; /* do we need to enable the touch panel reader */ if (wm->id == WM9705_ID2) { if (wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD) & WM97XX_PEN_DOWN) wm->pen_is_down = 1; else wm->pen_is_down = 0; } else { u16 status, pol; mutex_lock(&wm->codec_mutex); status = wm97xx_reg_read(wm, AC97_GPIO_STATUS); pol = wm97xx_reg_read(wm, AC97_GPIO_POLARITY); if (WM97XX_GPIO_13 & pol & status) { wm->pen_is_down = 1; wm97xx_reg_write(wm, AC97_GPIO_POLARITY, pol & ~WM97XX_GPIO_13); } else { wm->pen_is_down = 0; wm97xx_reg_write(wm, AC97_GPIO_POLARITY, pol | WM97XX_GPIO_13); } if (wm->id == WM9712_ID2 && wm->variant != WM97xx_WM1613) wm97xx_reg_write(wm, AC97_GPIO_STATUS, (status & ~WM97XX_GPIO_13) << 1); else wm97xx_reg_write(wm, AC97_GPIO_STATUS, status & ~WM97XX_GPIO_13); mutex_unlock(&wm->codec_mutex); } /* If the system is not using continuous mode or it provides a * pen down operation then we need to schedule polls while the * pen is down. Otherwise the machine driver is responsible * for scheduling reads. */ if (!wm->mach_ops->acc_enabled || wm->mach_ops->acc_pen_down) { if (wm->pen_is_down && !pen_was_down) { /* Data is not available immediately on pen down */ queue_delayed_work(wm->ts_workq, &wm->ts_reader, 1); } /* Let ts_reader report the pen up for debounce. */ if (!wm->pen_is_down && pen_was_down) wm->pen_is_down = 1; } if (!wm->pen_is_down && wm->mach_ops->acc_enabled) wm->mach_ops->acc_pen_up(wm); wm->mach_ops->irq_enable(wm, 1); } /* * Codec PENDOWN irq handler * * We have to disable the codec interrupt in the handler because it * can take up to 1ms to clear the interrupt source. We schedule a task * in a work queue to do the actual interaction with the chip. The * interrupt is then enabled again in the slow handler when the source * has been cleared. */ static irqreturn_t wm97xx_pen_interrupt(int irq, void *dev_id) { struct wm97xx *wm = dev_id; if (!work_pending(&wm->pen_event_work)) { wm->mach_ops->irq_enable(wm, 0); queue_work(wm->ts_workq, &wm->pen_event_work); } return IRQ_HANDLED; } /* * initialise pen IRQ handler and workqueue */ static int wm97xx_init_pen_irq(struct wm97xx *wm) { u16 reg; /* If an interrupt is supplied an IRQ enable operation must also be * provided. */ BUG_ON(!wm->mach_ops->irq_enable); if (request_irq(wm->pen_irq, wm97xx_pen_interrupt, IRQF_SHARED, "wm97xx-pen", wm)) { dev_err(wm->dev, "Failed to register pen down interrupt, polling"); wm->pen_irq = 0; return -EINVAL; } /* Configure GPIO as interrupt source on WM971x */ if (wm->id != WM9705_ID2) { BUG_ON(!wm->mach_ops->irq_gpio); reg = wm97xx_reg_read(wm, AC97_MISC_AFE); wm97xx_reg_write(wm, AC97_MISC_AFE, reg & ~(wm->mach_ops->irq_gpio)); reg = wm97xx_reg_read(wm, 0x5a); wm97xx_reg_write(wm, 0x5a, reg & ~0x0001); } return 0; } static int wm97xx_read_samples(struct wm97xx *wm) { struct wm97xx_data data; int rc; mutex_lock(&wm->codec_mutex); if (wm->mach_ops && wm->mach_ops->acc_enabled) rc = wm->mach_ops->acc_pen_down(wm); else rc = wm->codec->poll_touch(wm, &data); if (rc & RC_PENUP) { if (wm->pen_is_down) { wm->pen_is_down = 0; dev_dbg(wm->dev, "pen up\n"); input_report_abs(wm->input_dev, ABS_PRESSURE, 0); input_report_key(wm->input_dev, BTN_TOUCH, 0); input_sync(wm->input_dev); } else if (!(rc & RC_AGAIN)) { /* We need high frequency updates only while * pen is down, the user never will be able to * touch screen faster than a few times per * second... On the other hand, when the user * is actively working with the touchscreen we * don't want to lose the quick response. So we * will slowly increase sleep time after the * pen is up and quicky restore it to ~one task * switch when pen is down again. */ if (wm->ts_reader_interval < HZ / 10) wm->ts_reader_interval++; } } else if (rc & RC_VALID) { dev_dbg(wm->dev, "pen down: x=%x:%d, y=%x:%d, pressure=%x:%d\n", data.x >> 12, data.x & 0xfff, data.y >> 12, data.y & 0xfff, data.p >> 12, data.p & 0xfff); input_report_abs(wm->input_dev, ABS_X, data.x & 0xfff); input_report_abs(wm->input_dev, ABS_Y, data.y & 0xfff); input_report_abs(wm->input_dev, ABS_PRESSURE, data.p & 0xfff); input_report_key(wm->input_dev, BTN_TOUCH, 1); input_sync(wm->input_dev); wm->pen_is_down = 1; wm->ts_reader_interval = wm->ts_reader_min_interval; } else if (rc & RC_PENDOWN) { dev_dbg(wm->dev, "pen down\n"); wm->pen_is_down = 1; wm->ts_reader_interval = wm->ts_reader_min_interval; } mutex_unlock(&wm->codec_mutex); return rc; } /* * The touchscreen sample reader. */ static void wm97xx_ts_reader(struct work_struct *work) { int rc; struct wm97xx *wm = container_of(work, struct wm97xx, ts_reader.work); BUG_ON(!wm->codec); do { rc = wm97xx_read_samples(wm); } while (rc & RC_AGAIN); if (wm->pen_is_down || !wm->pen_irq) queue_delayed_work(wm->ts_workq, &wm->ts_reader, wm->ts_reader_interval); } /** * wm97xx_ts_input_open - Open the touch screen input device. * @idev: Input device to be opened. * * Called by the input sub system to open a wm97xx touchscreen device. * Starts the touchscreen thread and touch digitiser. */ static int wm97xx_ts_input_open(struct input_dev *idev) { struct wm97xx *wm = input_get_drvdata(idev); wm->ts_workq = create_singlethread_workqueue("kwm97xx"); if (wm->ts_workq == NULL) { dev_err(wm->dev, "Failed to create workqueue\n"); return -EINVAL; } /* start digitiser */ if (wm->mach_ops && wm->mach_ops->acc_enabled) wm->codec->acc_enable(wm, 1); wm->codec->dig_enable(wm, 1); INIT_DELAYED_WORK(&wm->ts_reader, wm97xx_ts_reader); INIT_WORK(&wm->pen_event_work, wm97xx_pen_irq_worker); wm->ts_reader_min_interval = HZ >= 100 ? HZ / 100 : 1; if (wm->ts_reader_min_interval < 1) wm->ts_reader_min_interval = 1; wm->ts_reader_interval = wm->ts_reader_min_interval; wm->pen_is_down = 0; if (wm->pen_irq) wm97xx_init_pen_irq(wm); else dev_err(wm->dev, "No IRQ specified\n"); /* If we either don't have an interrupt for pen down events or * failed to acquire it then we need to poll. */ if (wm->pen_irq == 0) queue_delayed_work(wm->ts_workq, &wm->ts_reader, wm->ts_reader_interval); return 0; } /** * wm97xx_ts_input_close - Close the touch screen input device. * @idev: Input device to be closed. * * Called by the input sub system to close a wm97xx touchscreen * device. Kills the touchscreen thread and stops the touch * digitiser. */ static void wm97xx_ts_input_close(struct input_dev *idev) { struct wm97xx *wm = input_get_drvdata(idev); u16 reg; if (wm->pen_irq) { /* Return the interrupt to GPIO usage (disabling it) */ if (wm->id != WM9705_ID2) { BUG_ON(!wm->mach_ops->irq_gpio); reg = wm97xx_reg_read(wm, AC97_MISC_AFE); wm97xx_reg_write(wm, AC97_MISC_AFE, reg | wm->mach_ops->irq_gpio); } free_irq(wm->pen_irq, wm); } wm->pen_is_down = 0; /* Balance out interrupt disables/enables */ if (cancel_work_sync(&wm->pen_event_work)) wm->mach_ops->irq_enable(wm, 1); /* ts_reader rearms itself so we need to explicitly stop it * before we destroy the workqueue. */ cancel_delayed_work_sync(&wm->ts_reader); destroy_workqueue(wm->ts_workq); /* stop digitiser */ wm->codec->dig_enable(wm, 0); if (wm->mach_ops && wm->mach_ops->acc_enabled) wm->codec->acc_enable(wm, 0); } static int wm97xx_probe(struct device *dev) { struct wm97xx *wm; struct wm97xx_pdata *pdata = dev->platform_data; int ret = 0, id = 0; wm = kzalloc(sizeof(struct wm97xx), GFP_KERNEL); if (!wm) return -ENOMEM; mutex_init(&wm->codec_mutex); wm->dev = dev; dev_set_drvdata(dev, wm); wm->ac97 = to_ac97_t(dev); /* check that we have a supported codec */ id = wm97xx_reg_read(wm, AC97_VENDOR_ID1); if (id != WM97XX_ID1) { dev_err(dev, "Device with vendor %04x is not a wm97xx\n", id); ret = -ENODEV; goto alloc_err; } wm->id = wm97xx_reg_read(wm, AC97_VENDOR_ID2); wm->variant = WM97xx_GENERIC; dev_info(wm->dev, "detected a wm97%02x codec\n", wm->id & 0xff); switch (wm->id & 0xff) { #ifdef CONFIG_TOUCHSCREEN_WM9705 case 0x05: wm->codec = &wm9705_codec; break; #endif #ifdef CONFIG_TOUCHSCREEN_WM9712 case 0x12: wm->codec = &wm9712_codec; break; #endif #ifdef CONFIG_TOUCHSCREEN_WM9713 case 0x13: wm->codec = &wm9713_codec; break; #endif default: dev_err(wm->dev, "Support for wm97%02x not compiled in.\n", wm->id & 0xff); ret = -ENODEV; goto alloc_err; } /* set up physical characteristics */ wm->codec->phy_init(wm); /* load gpio cache */ wm->gpio[0] = wm97xx_reg_read(wm, AC97_GPIO_CFG); wm->gpio[1] = wm97xx_reg_read(wm, AC97_GPIO_POLARITY); wm->gpio[2] = wm97xx_reg_read(wm, AC97_GPIO_STICKY); wm->gpio[3] = wm97xx_reg_read(wm, AC97_GPIO_WAKEUP); wm->gpio[4] = wm97xx_reg_read(wm, AC97_GPIO_STATUS); wm->gpio[5] = wm97xx_reg_read(wm, AC97_MISC_AFE); wm->input_dev = input_allocate_device(); if (wm->input_dev == NULL) { ret = -ENOMEM; goto alloc_err; } /* set up touch configuration */ wm->input_dev->name = "wm97xx touchscreen"; wm->input_dev->phys = "wm97xx"; wm->input_dev->open = wm97xx_ts_input_open; wm->input_dev->close = wm97xx_ts_input_close; __set_bit(EV_ABS, wm->input_dev->evbit); __set_bit(EV_KEY, wm->input_dev->evbit); __set_bit(BTN_TOUCH, wm->input_dev->keybit); input_set_abs_params(wm->input_dev, ABS_X, abs_x[0], abs_x[1], abs_x[2], 0); input_set_abs_params(wm->input_dev, ABS_Y, abs_y[0], abs_y[1], abs_y[2], 0); input_set_abs_params(wm->input_dev, ABS_PRESSURE, abs_p[0], abs_p[1], abs_p[2], 0); input_set_drvdata(wm->input_dev, wm); wm->input_dev->dev.parent = dev; ret = input_register_device(wm->input_dev); if (ret < 0) goto dev_alloc_err; /* register our battery device */ wm->battery_dev = platform_device_alloc("wm97xx-battery", -1); if (!wm->battery_dev) { ret = -ENOMEM; goto batt_err; } platform_set_drvdata(wm->battery_dev, wm); wm->battery_dev->dev.parent = dev; wm->battery_dev->dev.platform_data = pdata; ret = platform_device_add(wm->battery_dev); if (ret < 0) goto batt_reg_err; /* register our extended touch device (for machine specific * extensions) */ wm->touch_dev = platform_device_alloc("wm97xx-touch", -1); if (!wm->touch_dev) { ret = -ENOMEM; goto touch_err; } platform_set_drvdata(wm->touch_dev, wm); wm->touch_dev->dev.parent = dev; wm->touch_dev->dev.platform_data = pdata; ret = platform_device_add(wm->touch_dev); if (ret < 0) goto touch_reg_err; return ret; touch_reg_err: platform_device_put(wm->touch_dev); touch_err: platform_device_del(wm->battery_dev); batt_reg_err: platform_device_put(wm->battery_dev); batt_err: input_unregister_device(wm->input_dev); wm->input_dev = NULL; dev_alloc_err: input_free_device(wm->input_dev); alloc_err: kfree(wm); return ret; } static int wm97xx_remove(struct device *dev) { struct wm97xx *wm = dev_get_drvdata(dev); platform_device_unregister(wm->battery_dev); platform_device_unregister(wm->touch_dev); input_unregister_device(wm->input_dev); kfree(wm); return 0; } #ifdef CONFIG_PM static int wm97xx_suspend(struct device *dev, pm_message_t state) { struct wm97xx *wm = dev_get_drvdata(dev); u16 reg; int suspend_mode; if (device_may_wakeup(&wm->input_dev->dev)) suspend_mode = wm->suspend_mode; else suspend_mode = 0; if (wm->input_dev->users) cancel_delayed_work_sync(&wm->ts_reader); /* Power down the digitiser (bypassing the cache for resume) */ reg = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER2); reg &= ~WM97XX_PRP_DET_DIG; if (wm->input_dev->users) reg |= suspend_mode; wm->ac97->bus->ops->write(wm->ac97, AC97_WM97XX_DIGITISER2, reg); /* WM9713 has an additional power bit - turn it off if there * are no users or if suspend mode is zero. */ if (wm->id == WM9713_ID2 && (!wm->input_dev->users || !suspend_mode)) { reg = wm97xx_reg_read(wm, AC97_EXTENDED_MID) | 0x8000; wm97xx_reg_write(wm, AC97_EXTENDED_MID, reg); } return 0; } static int wm97xx_resume(struct device *dev) { struct wm97xx *wm = dev_get_drvdata(dev); /* restore digitiser and gpios */ if (wm->id == WM9713_ID2) { wm97xx_reg_write(wm, AC97_WM9713_DIG1, wm->dig[0]); wm97xx_reg_write(wm, 0x5a, wm->misc); if (wm->input_dev->users) { u16 reg; reg = wm97xx_reg_read(wm, AC97_EXTENDED_MID) & 0x7fff; wm97xx_reg_write(wm, AC97_EXTENDED_MID, reg); } } wm97xx_reg_write(wm, AC97_WM9713_DIG2, wm->dig[1]); wm97xx_reg_write(wm, AC97_WM9713_DIG3, wm->dig[2]); wm97xx_reg_write(wm, AC97_GPIO_CFG, wm->gpio[0]); wm97xx_reg_write(wm, AC97_GPIO_POLARITY, wm->gpio[1]); wm97xx_reg_write(wm, AC97_GPIO_STICKY, wm->gpio[2]); wm97xx_reg_write(wm, AC97_GPIO_WAKEUP, wm->gpio[3]); wm97xx_reg_write(wm, AC97_GPIO_STATUS, wm->gpio[4]); wm97xx_reg_write(wm, AC97_MISC_AFE, wm->gpio[5]); if (wm->input_dev->users && !wm->pen_irq) { wm->ts_reader_interval = wm->ts_reader_min_interval; queue_delayed_work(wm->ts_workq, &wm->ts_reader, wm->ts_reader_interval); } return 0; } #else #define wm97xx_suspend NULL #define wm97xx_resume NULL #endif /* * Machine specific operations */ int wm97xx_register_mach_ops(struct wm97xx *wm, struct wm97xx_mach_ops *mach_ops) { mutex_lock(&wm->codec_mutex); if (wm->mach_ops) { mutex_unlock(&wm->codec_mutex); return -EINVAL; } wm->mach_ops = mach_ops; mutex_unlock(&wm->codec_mutex); return 0; } EXPORT_SYMBOL_GPL(wm97xx_register_mach_ops); void wm97xx_unregister_mach_ops(struct wm97xx *wm) { mutex_lock(&wm->codec_mutex); wm->mach_ops = NULL; mutex_unlock(&wm->codec_mutex); } EXPORT_SYMBOL_GPL(wm97xx_unregister_mach_ops); static struct device_driver wm97xx_driver = { .name = "wm97xx-ts", .bus = &ac97_bus_type, .owner = THIS_MODULE, .probe = wm97xx_probe, .remove = wm97xx_remove, .suspend = wm97xx_suspend, .resume = wm97xx_resume, }; static int __init wm97xx_init(void) { return driver_register(&wm97xx_driver); } static void __exit wm97xx_exit(void) { driver_unregister(&wm97xx_driver); } module_init(wm97xx_init); module_exit(wm97xx_exit); /* Module information */ MODULE_AUTHOR("Liam Girdwood "); MODULE_DESCRIPTION("WM97xx Core - Touch Screen / AUX ADC / GPIO Driver"); MODULE_LICENSE("GPL");