1 files changed, 456 insertions, 0 deletions

diff --git a/drivers/input/touchscreen/colibri-vf50-ts.c b/drivers/input/touchscreen/colibri-vf50-ts.c
new file mode 100644
index 000000000000..5b0a796d3f54
--- /dev/null
+++ b/drivers/input/touchscreen/colibri-vf50-ts.c
@@ -0,0 +1,456 @@
+/* Copyright 2013 Toradex AG
+ *
+ * Toradex Colibri VF50 Touchscreen driver
+ *
+ * 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.
+*/
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/sched.h>
+#include <linux/list.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/clk.h>
+#include <linux/interrupt.h>
+#include <linux/uaccess.h>
+#include <linux/miscdevice.h>
+#include <linux/mvf_adc.h>
+#include <linux/device.h>
+#include <linux/cdev.h>
+#include <linux/input.h>
+#include <linux/delay.h>
+#include <linux/gpio.h>
+#include <mach/colibri-ts.h>
+
+#define DRIVER_NAME "colibri-vf50-ts"
+#define DRV_VERSION "1.0"
+
+#define MVF_ADC_MAX ((1 << 12) - 1)
+
+#define COLI_TOUCH_MIN_DELAY_US 1000
+#define COLI_TOUCH_MAX_DELAY_US 2000
+
+#define COL_TS_GPIO_XP 0
+#define COL_TS_GPIO_XM 1
+#define COL_TS_GPIO_YP 2
+#define COL_TS_GPIO_YM 3
+#define COL_TS_GPIO_TOUCH 4
+#define COL_TS_GPIO_PULLUP 5
+
+#define COL_TS_WIRE_XP 0
+#define COL_TS_WIRE_XM 1
+#define COL_TS_WIRE_YP 2
+#define COL_TS_WIRE_YM 3
+
+struct col_ts_driver {
+	int enable_state;
+	struct gpio *control_gpio;
+};
+
+/* GPIO */
+static struct gpio col_ts_gpios[] = {
+	[COL_TS_GPIO_XP] = { 13, GPIOF_IN, "Touchscreen PX" },
+	[COL_TS_GPIO_XM] = { 5, GPIOF_IN, "Touchscreen MX" },
+	[COL_TS_GPIO_YP] = { 12, GPIOF_IN, "Touchscreen PY" },
+	[COL_TS_GPIO_YM] = { 4, GPIOF_IN, "Touchscreen MY" },
+	[COL_TS_GPIO_TOUCH] = { 8, GPIOF_IN, "Touchscreen (Touch interrupt)" },
+	[COL_TS_GPIO_PULLUP] = { 9, GPIOF_IN, "Touchscreen (Pull-up)" },
+};
+
+/* GPIOs and their FET configuration */
+static struct col_ts_driver col_ts_drivers[] = {
+	[COL_TS_WIRE_XP] = {
+		.enable_state = 0,
+		.control_gpio = &col_ts_gpios[COL_TS_GPIO_XP],
+	},
+	[COL_TS_WIRE_XM] = {
+		.enable_state = 1,
+		.control_gpio = &col_ts_gpios[COL_TS_GPIO_XM],
+	},
+	[COL_TS_WIRE_YP] = {
+		.enable_state = 0,
+		.control_gpio = &col_ts_gpios[COL_TS_GPIO_YP],
+	},
+	[COL_TS_WIRE_YM] = {
+		.enable_state = 1,
+		.control_gpio  = &col_ts_gpios[COL_TS_GPIO_YM],
+	},
+};
+
+#define col_ts_init_wire(ts_gpio) \
+	gpio_direction_output(col_ts_drivers[ts_gpio].control_gpio->gpio, \
+			!col_ts_drivers[ts_gpio].enable_state)
+
+#define col_ts_enable_wire(ts_gpio) \
+	gpio_set_value(col_ts_drivers[ts_gpio].control_gpio->gpio, \
+			col_ts_drivers[ts_gpio].enable_state)
+
+#define col_ts_disable_wire(ts_gpio) \
+	gpio_set_value(col_ts_drivers[ts_gpio].control_gpio->gpio, \
+			!col_ts_drivers[ts_gpio].enable_state)
+
+struct adc_touch_device {
+	struct platform_device	*pdev;
+
+	bool stop_touchscreen;
+
+	int pen_irq;
+	struct input_dev	*ts_input;
+	struct workqueue_struct *ts_workqueue;
+	struct work_struct	ts_work;
+};
+
+struct adc_touch_device *touch;
+
+/*
+ * Enables given plates and measures touch parameters using ADC
+ */
+static int adc_ts_measure(int plate1, int plate2, int adc, int adc_channel)
+{
+	int i, value = 0;
+	col_ts_enable_wire(plate1);
+	col_ts_enable_wire(plate2);
+
+	/* Use hrtimer sleep since msleep sleeps 10ms+ */
+	usleep_range(COLI_TOUCH_MIN_DELAY_US, COLI_TOUCH_MAX_DELAY_US);
+
+	for (i = 0; i < 5; i++) {
+		int ret = mvf_adc_register_and_convert(adc, adc_channel);
+		if (ret < 0)
+			return -EINVAL;
+
+		value += ret;
+	}
+
+	value /= 5;
+
+	col_ts_disable_wire(plate1);
+	col_ts_disable_wire(plate2);
+
+	return value;
+}
+
+/*
+ * Enable touch detection using falling edge detection on XM 
+ */
+static void adc_ts_enable_touch_detection(struct adc_touch_device *adc_ts)
+{
+	struct colibri_ts_platform_data *pdata = adc_ts->pdev->dev.platform_data;
+
+	/* Enable plate YM (needs to be strong 0) */
+	col_ts_enable_wire(COL_TS_WIRE_YM);
+
+	/* Let the platform mux to GPIO in order to enable Pull-Up on GPIO */
+	if (pdata->mux_pen_interrupt)
+		pdata->mux_pen_interrupt(adc_ts->pdev);
+}
+
+/*
+ * ADC touch screen sampling worker function
+ */
+static void adc_ts_work(struct work_struct *ts_work)
+{
+	struct adc_touch_device *adc_ts = container_of(ts_work,
+				struct adc_touch_device, ts_work);
+	struct device *dev = &adc_ts->pdev->dev;
+	int val_x, val_y, val_z1, val_z2, val_p = 0;
+
+	struct adc_feature feature = {
+		.channel = ADC0,
+		.clk_sel = ADCIOC_BUSCLK_SET,
+		.clk_div_num = 1,
+		.res_mode = 12,
+		.sam_time = 6,
+		.lp_con = ADCIOC_LPOFF_SET,
+		.hs_oper = ADCIOC_HSOFF_SET,
+		.vol_ref = ADCIOC_VR_VREF_SET,
+		.tri_sel = ADCIOC_SOFTTS_SET,
+		.ha_sel = ADCIOC_HA_SET,
+		.ha_sam = 8,
+		.do_ena = ADCIOC_DOEOFF_SET,
+		.ac_ena = ADCIOC_ADACKENOFF_SET,
+		.dma_ena = ADCIDC_DMAOFF_SET,
+		.cc_ena = ADCIOC_CCEOFF_SET,
+		.compare_func_ena = ADCIOC_ACFEOFF_SET,
+		.range_ena = ADCIOC_ACRENOFF_SET,
+		.greater_ena = ADCIOC_ACFGTOFF_SET,
+		.result0 = 0,
+		.result1 = 0,
+	};
+
+	mvf_adc_initiate(0);
+	mvf_adc_set(0, &feature);
+
+	mvf_adc_initiate(1);
+	mvf_adc_set(1, &feature);
+
+	while (!adc_ts->stop_touchscreen)
+	{
+		/* X-Direction */
+		val_x = adc_ts_measure(COL_TS_WIRE_XP, COL_TS_WIRE_XM, 1, 0);
+		if (val_x < 0)
+			continue;
+
+		/* Y-Direction */
+		val_y = adc_ts_measure(COL_TS_WIRE_YP, COL_TS_WIRE_YM, 0, 0);
+		if (val_y < 0)
+			continue;
+
+		/* Touch pressure
+		 * Measure on XP/YM
+		 */
+		val_z1 = adc_ts_measure(COL_TS_WIRE_YP, COL_TS_WIRE_XM, 0, 1);
+		if (val_z1 < 0)
+			continue;
+		val_z2 = adc_ts_measure(COL_TS_WIRE_YP, COL_TS_WIRE_XM, 1, 2);
+		if (val_z2 < 0)
+			continue;
+
+		/* According to datasheet of our touchscreen, 
+		 * resistance on X axis is 400~1200.. 
+		 */
+	//	if ((val_z2 - val_z1) < (MVF_ADC_MAX - (1<<9)) {
+		/* Validate signal (avoid calculation using noise) */
+		if (val_z1 > 64 && val_x > 64) {
+			/* Calculate resistance between the plates
+			 * lower resistance means higher pressure */
+			int r_x = (1000 * val_x) / MVF_ADC_MAX;
+			val_p = (r_x * val_z2) / val_z1 - r_x;
+		} else {
+			val_p = 2000;
+		}
+		/*
+		dev_dbg(dev, "Measured values: x: %d, y: %d, z1: %d, z2: %d, "
+			"p: %d\n", val_x, val_y, val_z1, val_z2, val_p);
+*/
+		/*
+		 * If touch pressure is too low, stop measuring and reenable
+		 * touch detection
+		 */
+		if (val_p > 1050)
+			break;
+
+		/* Report touch position and sleep for next measurement */
+		input_report_abs(adc_ts->ts_input, ABS_X, MVF_ADC_MAX - val_x);
+		input_report_abs(adc_ts->ts_input, ABS_Y, MVF_ADC_MAX - val_y);
+		input_report_abs(adc_ts->ts_input, ABS_PRESSURE, 2000 - val_p);
+		input_report_key(adc_ts->ts_input, BTN_TOUCH, 1);
+		input_sync(adc_ts->ts_input);
+
+		msleep(10);
+	}
+
+	/* Report no more touch, reenable touch detection */
+	input_report_abs(adc_ts->ts_input, ABS_PRESSURE, 0);
+	input_report_key(adc_ts->ts_input, BTN_TOUCH, 0);
+	input_sync(adc_ts->ts_input);
+
+	/* Wait the pull-up to be stable on high */
+	adc_ts_enable_touch_detection(adc_ts);
+	msleep(10);
+
+	/* Reenable IRQ to detect touch */
+	enable_irq(adc_ts->pen_irq);
+
+	dev_dbg(dev, "Reenabled touch detection interrupt\n");
+}
+
+static irqreturn_t adc_tc_touched(int irq, void *dev_id)
+{
+	struct adc_touch_device *adc_ts = (struct adc_touch_device *)dev_id;
+	struct device *dev = &adc_ts->pdev->dev;
+	struct colibri_ts_platform_data *pdata = adc_ts->pdev->dev.platform_data;
+
+	dev_dbg(dev, "Touch detected, start worker thread\n");
+
+	/* Stop IRQ */
+	disable_irq_nosync(irq);
+
+	/* Disable the touch detection plates */
+	col_ts_disable_wire(COL_TS_WIRE_YM);
+
+	/* Let the platform mux to GPIO in order to enable Pull-Up on GPIO */
+	if (pdata->mux_adc)
+		pdata->mux_adc(adc_ts->pdev);
+
+	/* Start worker thread */
+	queue_work(adc_ts->ts_workqueue, &adc_ts->ts_work);
+
+	return IRQ_HANDLED;
+}
+
+static int adc_ts_open(struct input_dev *dev_input)
+{
+	int ret;
+	struct adc_touch_device *adc_ts = input_get_drvdata(dev_input);
+	struct device *dev = &adc_ts->pdev->dev;
+	struct colibri_ts_platform_data *pdata = adc_ts->pdev->dev.platform_data;
+
+	dev_dbg(dev, "Input device %s opened, starting touch detection\n", 
+			dev_input->name);
+
+	adc_ts->stop_touchscreen = false;
+
+	/* Initialize GPIOs, leave FETs closed by default */
+	col_ts_init_wire(COL_TS_WIRE_XP);
+	col_ts_init_wire(COL_TS_WIRE_XM);
+	col_ts_init_wire(COL_TS_WIRE_YP);
+	col_ts_init_wire(COL_TS_WIRE_YM);
+
+	/* Mux detection before request IRQ, wait for pull-up to settle */
+	adc_ts_enable_touch_detection(adc_ts);
+	msleep(10);
+
+	adc_ts->pen_irq = gpio_to_irq(pdata->gpio_pen);
+	if (adc_ts->pen_irq < 0) {
+		dev_err(dev, "Unable to get IRQ for GPIO %d\n", pdata->gpio_pen);
+		return adc_ts->pen_irq;
+	}
+
+	ret = request_irq(adc_ts->pen_irq, adc_tc_touched, IRQF_TRIGGER_FALLING,
+			"touch detected", adc_ts);
+	if (ret < 0) {
+		dev_err(dev, "Unable to request IRQ %d\n", adc_ts->pen_irq);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void adc_ts_close(struct input_dev *dev_input)
+{
+	struct adc_touch_device *adc_ts = input_get_drvdata(dev_input);
+	struct device *dev = &adc_ts->pdev->dev;
+
+	free_irq(gpio_to_irq(col_ts_gpios[COL_TS_GPIO_TOUCH].gpio), adc_ts);
+
+	adc_ts->stop_touchscreen = true;
+
+	/* Wait until touchscreen thread finishes any possible remnants. */
+	cancel_work_sync(&adc_ts->ts_work);
+
+	dev_dbg(dev, "Input device %s closed, disable touch detection\n", 
+			dev_input->name);
+}
+
+
+static int __devinit adc_ts_probe(struct platform_device *pdev)
+{
+	int ret = 0;
+	struct device *dev = &pdev->dev;
+	struct input_dev *input;
+	struct adc_touch_device *adc_ts;
+
+	adc_ts = kzalloc(sizeof(struct adc_touch_device), GFP_KERNEL);
+	if (!adc_ts) {
+		dev_err(dev, "Failed to allocate TS device!\n");
+		return -ENOMEM;
+	}
+
+	adc_ts->pdev = pdev;
+
+	input = input_allocate_device();
+	if (!input) {
+		dev_err(dev, "Failed to allocate TS input device!\n");
+		ret = -ENOMEM;
+		goto err_input_allocate;
+	}
+
+	input->name = DRIVER_NAME;
+	input->id.bustype = BUS_HOST;
+	input->dev.parent = dev;
+	input->open = adc_ts_open;
+	input->close = adc_ts_close;
+
+	__set_bit(EV_ABS, input->evbit);
+	__set_bit(EV_KEY, input->evbit);
+	__set_bit(BTN_TOUCH, input->keybit);
+	input_set_abs_params(input, ABS_X, 0, MVF_ADC_MAX, 0, 0);
+	input_set_abs_params(input, ABS_Y, 0, MVF_ADC_MAX, 0, 0);
+	input_set_abs_params(input, ABS_PRESSURE, 0, MVF_ADC_MAX, 0, 0);
+
+	adc_ts->ts_input = input;
+	input_set_drvdata(input, adc_ts);
+	ret = input_register_device(input);
+	if (ret) {
+		dev_err(dev, "failed to register input device\n");
+		goto err;
+	}
+
+	/* Create workqueue for ADC sampling and calculation */
+	INIT_WORK(&adc_ts->ts_work, adc_ts_work);
+	adc_ts->ts_workqueue = create_singlethread_workqueue("mvf-adc-touch");
+
+	if (!adc_ts->ts_workqueue) {
+		dev_err(dev, "failed to create workqueue");
+		goto err;
+	}
+
+	/* Request GPIOs for FETs and touch detection */
+	ret = gpio_request_array(col_ts_gpios, COL_TS_GPIO_PULLUP + 1);
+	if (ret) {
+		dev_err(dev, "failed to request GPIOs\n");
+		goto err;
+	}
+
+	dev_info(dev, "attached driver successfully\n");
+
+	return 0;
+err:
+	input_free_device(touch->ts_input);
+
+err_input_allocate:
+	kfree(adc_ts);
+
+	return ret;
+}
+
+static int __devexit adc_ts_remove(struct platform_device *pdev)
+{
+	struct adc_touch_device *adc_ts = platform_get_drvdata(pdev);
+
+	input_unregister_device(adc_ts->ts_input);
+
+	destroy_workqueue(adc_ts->ts_workqueue);
+	kfree(adc_ts->ts_input);
+	kfree(adc_ts);
+
+	return 0;
+}
+
+static struct platform_driver adc_ts_driver = {
+	.driver		= {
+		.name	= DRIVER_NAME,
+		.owner	= THIS_MODULE,
+	},
+	.probe		= adc_ts_probe,
+	.remove		= __devexit_p(adc_ts_remove),
+};
+
+static int __init adc_ts_init(void)
+{
+	int ret;
+
+	ret = platform_driver_register(&adc_ts_driver);
+	if (ret)
+		printk(KERN_ERR "%s: failed to add adc touchscreen driver\n", 
+				__func__);
+
+	return ret;
+}
+
+static void __exit adc_ts_exit(void)
+{
+	platform_driver_unregister(&adc_ts_driver);
+}
+module_init(adc_ts_init);
+module_exit(adc_ts_exit);
+
+MODULE_AUTHOR("Stefan Agner");
+MODULE_DESCRIPTION("Colibri VF50 Touchscreen driver");
+MODULE_LICENSE("GPL v2");
+MODULE_VERSION(DRV_VERSION);