--- /dev/null
+/*
+ * 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);
+
+ 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 = {
+ .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);
Code Review / kvmfornfv.git / blobdiff