| /* |
| * 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 <linux/platform_device.h> |
| #include <linux/mfd/mc13783.h> |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <linux/input.h> |
| #include <linux/sched.h> |
| #include <linux/slab.h> |
| #include <linux/init.h> |
| |
| #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]; |
| struct mc13xxx_ts_platform_data *touch; |
| }; |
| |
| 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->touch->ato, priv->touch->atox, |
| 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; |
| priv->touch = dev_get_platdata(&pdev->dev); |
| if (!priv->touch) { |
| dev_err(&pdev->dev, "missing platform data\n"); |
| ret = -ENODEV; |
| goto err_free_mem; |
| } |
| |
| /* |
| * 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 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 = mc13783_ts_remove, |
| .driver = { |
| .owner = THIS_MODULE, |
| .name = MC13783_TS_NAME, |
| }, |
| }; |
| |
| module_platform_driver_probe(mc13783_ts_driver, mc13783_ts_probe); |
| |
| MODULE_DESCRIPTION("MC13783 input touchscreen driver"); |
| MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>"); |
| MODULE_LICENSE("GPL v2"); |
| MODULE_ALIAS("platform:" MC13783_TS_NAME); |