diff options
Diffstat (limited to 'drivers/input/touchscreen/mc13783_ts.c')
| -rw-r--r-- | drivers/input/touchscreen/mc13783_ts.c | 255 |
1 files changed, 255 insertions, 0 deletions
diff --git a/drivers/input/touchscreen/mc13783_ts.c b/drivers/input/touchscreen/mc13783_ts.c new file mode 100644 index 000000000..913e25a99 --- /dev/null +++ b/drivers/input/touchscreen/mc13783_ts.c @@ -0,0 +1,255 @@ +/* + * 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); |