/* * Driver for the Freescale Semiconductor MC13783 touchscreen. * * Copyright 2004-2007 Freescale Semiconductor, Inc. All Rights Reserved. * Copyright (C) 2009 Sascha Hauer, Pengutronix * * Initial development of this code was funded by * Phytec Messtechnik GmbH, http://www.phytec.de/ * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 as published by * the Free Software Foundation. */ #include #include #include #include #include #include #include #include #define MC13783_TS_NAME "mc13783-ts" #define DEFAULT_SAMPLE_TOLERANCE 300 static unsigned int sample_tolerance = DEFAULT_SAMPLE_TOLERANCE; module_param(sample_tolerance, uint, S_IRUGO | S_IWUSR); MODULE_PARM_DESC(sample_tolerance, "If the minimal and maximal value read out for one axis (out " "of three) differ by this value (default: " __stringify(DEFAULT_SAMPLE_TOLERANCE) ") or more, the reading " "is supposed to be wrong and is discarded. Set to 0 to " "disable this check."); struct mc13783_ts_priv { struct input_dev *idev; struct mc13xxx *mc13xxx; struct delayed_work work; struct workqueue_struct *workq; unsigned int sample[4]; }; static irqreturn_t mc13783_ts_handler(int irq, void *data) { struct mc13783_ts_priv *priv = data; mc13xxx_irq_ack(priv->mc13xxx, irq); /* * Kick off reading coordinates. Note that if work happens already * be queued for future execution (it rearms itself) it will not * be rescheduled for immediate execution here. However the rearm * delay is HZ / 50 which is acceptable. */ queue_delayed_work(priv->workq, &priv->work, 0); return IRQ_HANDLED; } #define sort3(a0, a1, a2) ({ \ if (a0 > a1) \ swap(a0, a1); \ if (a1 > a2) \ swap(a1, a2); \ if (a0 > a1) \ swap(a0, a1); \ }) static void mc13783_ts_report_sample(struct mc13783_ts_priv *priv) { struct input_dev *idev = priv->idev; int x0, x1, x2, y0, y1, y2; int cr0, cr1; /* * the values are 10-bit wide only, but the two least significant * bits are for future 12 bit use and reading yields 0 */ x0 = priv->sample[0] & 0xfff; x1 = priv->sample[1] & 0xfff; x2 = priv->sample[2] & 0xfff; y0 = priv->sample[3] & 0xfff; y1 = (priv->sample[0] >> 12) & 0xfff; y2 = (priv->sample[1] >> 12) & 0xfff; cr0 = (priv->sample[2] >> 12) & 0xfff; cr1 = (priv->sample[3] >> 12) & 0xfff; dev_dbg(&idev->dev, "x: (% 4d,% 4d,% 4d) y: (% 4d, % 4d,% 4d) cr: (% 4d, % 4d)\n", x0, x1, x2, y0, y1, y2, cr0, cr1); sort3(x0, x1, x2); sort3(y0, y1, y2); cr0 = (cr0 + cr1) / 2; if (!cr0 || !sample_tolerance || (x2 - x0 < sample_tolerance && y2 - y0 < sample_tolerance)) { /* report the median coordinate and average pressure */ if (cr0) { input_report_abs(idev, ABS_X, x1); input_report_abs(idev, ABS_Y, y1); dev_dbg(&idev->dev, "report (%d, %d, %d)\n", x1, y1, 0x1000 - cr0); queue_delayed_work(priv->workq, &priv->work, HZ / 50); } else dev_dbg(&idev->dev, "report release\n"); input_report_abs(idev, ABS_PRESSURE, cr0 ? 0x1000 - cr0 : cr0); input_report_key(idev, BTN_TOUCH, cr0); input_sync(idev); } else dev_dbg(&idev->dev, "discard event\n"); } static void mc13783_ts_work(struct work_struct *work) { struct mc13783_ts_priv *priv = container_of(work, struct mc13783_ts_priv, work.work); unsigned int mode = MC13XXX_ADC_MODE_TS; unsigned int channel = 12; if (mc13xxx_adc_do_conversion(priv->mc13xxx, mode, channel, priv->sample) == 0) mc13783_ts_report_sample(priv); } static int mc13783_ts_open(struct input_dev *dev) { struct mc13783_ts_priv *priv = input_get_drvdata(dev); int ret; mc13xxx_lock(priv->mc13xxx); mc13xxx_irq_ack(priv->mc13xxx, MC13XXX_IRQ_TS); ret = mc13xxx_irq_request(priv->mc13xxx, MC13XXX_IRQ_TS, mc13783_ts_handler, MC13783_TS_NAME, priv); if (ret) goto out; ret = mc13xxx_reg_rmw(priv->mc13xxx, MC13XXX_ADC0, MC13XXX_ADC0_TSMOD_MASK, MC13XXX_ADC0_TSMOD0); if (ret) mc13xxx_irq_free(priv->mc13xxx, MC13XXX_IRQ_TS, priv); out: mc13xxx_unlock(priv->mc13xxx); return ret; } static void mc13783_ts_close(struct input_dev *dev) { struct mc13783_ts_priv *priv = input_get_drvdata(dev); mc13xxx_lock(priv->mc13xxx); mc13xxx_reg_rmw(priv->mc13xxx, MC13XXX_ADC0, MC13XXX_ADC0_TSMOD_MASK, 0); mc13xxx_irq_free(priv->mc13xxx, MC13XXX_IRQ_TS, priv); mc13xxx_unlock(priv->mc13xxx); cancel_delayed_work_sync(&priv->work); } static int __init mc13783_ts_probe(struct platform_device *pdev) { struct mc13783_ts_priv *priv; struct input_dev *idev; int ret = -ENOMEM; priv = kzalloc(sizeof(*priv), GFP_KERNEL); idev = input_allocate_device(); if (!priv || !idev) goto err_free_mem; INIT_DELAYED_WORK(&priv->work, mc13783_ts_work); priv->mc13xxx = dev_get_drvdata(pdev->dev.parent); priv->idev = idev; /* * We need separate workqueue because mc13783_adc_do_conversion * uses keventd and thus would deadlock. */ priv->workq = create_singlethread_workqueue("mc13783_ts"); if (!priv->workq) goto err_free_mem; idev->name = MC13783_TS_NAME; idev->dev.parent = &pdev->dev; idev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); idev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); input_set_abs_params(idev, ABS_X, 0, 0xfff, 0, 0); input_set_abs_params(idev, ABS_Y, 0, 0xfff, 0, 0); input_set_abs_params(idev, ABS_PRESSURE, 0, 0xfff, 0, 0); idev->open = mc13783_ts_open; idev->close = mc13783_ts_close; input_set_drvdata(idev, priv); ret = input_register_device(priv->idev); if (ret) { dev_err(&pdev->dev, "register input device failed with %d\n", ret); goto err_destroy_wq; } platform_set_drvdata(pdev, priv); return 0; err_destroy_wq: destroy_workqueue(priv->workq); err_free_mem: input_free_device(idev); kfree(priv); return ret; } static int __devexit mc13783_ts_remove(struct platform_device *pdev) { struct mc13783_ts_priv *priv = platform_get_drvdata(pdev); platform_set_drvdata(pdev, NULL); destroy_workqueue(priv->workq); input_unregister_device(priv->idev); kfree(priv); return 0; } static struct platform_driver mc13783_ts_driver = { .remove = __devexit_p(mc13783_ts_remove), .driver = { .owner = THIS_MODULE, .name = MC13783_TS_NAME, }, }; static int __init mc13783_ts_init(void) { return platform_driver_probe(&mc13783_ts_driver, &mc13783_ts_probe); } module_init(mc13783_ts_init); static void __exit mc13783_ts_exit(void) { platform_driver_unregister(&mc13783_ts_driver); } module_exit(mc13783_ts_exit); MODULE_DESCRIPTION("MC13783 input touchscreen driver"); MODULE_AUTHOR("Sascha Hauer "); MODULE_LICENSE("GPL v2"); MODULE_ALIAS("platform:" MC13783_TS_NAME);