1 files changed, 406 insertions, 0 deletions
diff --git a/drivers/input/touchscreen/tsc2007.c b/drivers/input/touchscreen/tsc2007.c
new file mode 100644
index 00000000..1473d238
--- /dev/null
+++ b/drivers/input/touchscreen/tsc2007.c
@@ -0,0 +1,406 @@
+/*
+ * drivers/input/touchscreen/tsc2007.c
+ *
+ * Copyright (c) 2008 MtekVision Co., Ltd.
+ *	Kwangwoo Lee <kwlee@mtekvision.com>
+ *
+ * Using code from:
+ *  - ads7846.c
+ *	Copyright (c) 2005 David Brownell
+ *	Copyright (c) 2006 Nokia Corporation
+ *  - corgi_ts.c
+ *	Copyright (C) 2004-2005 Richard Purdie
+ *  - omap_ts.[hc], ads7846.h, ts_osk.c
+ *	Copyright (C) 2002 MontaVista Software
+ *	Copyright (C) 2004 Texas Instruments
+ *	Copyright (C) 2005 Dirk Behme
+ *
+ *  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/module.h>
+#include <linux/slab.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/i2c.h>
+#include <linux/i2c/tsc2007.h>
+
+#define TSC2007_MEASURE_TEMP0		(0x0 << 4)
+#define TSC2007_MEASURE_AUX		(0x2 << 4)
+#define TSC2007_MEASURE_TEMP1		(0x4 << 4)
+#define TSC2007_ACTIVATE_XN		(0x8 << 4)
+#define TSC2007_ACTIVATE_YN		(0x9 << 4)
+#define TSC2007_ACTIVATE_YP_XN		(0xa << 4)
+#define TSC2007_SETUP			(0xb << 4)
+#define TSC2007_MEASURE_X		(0xc << 4)
+#define TSC2007_MEASURE_Y		(0xd << 4)
+#define TSC2007_MEASURE_Z1		(0xe << 4)
+#define TSC2007_MEASURE_Z2		(0xf << 4)
+
+#define TSC2007_POWER_OFF_IRQ_EN	(0x0 << 2)
+#define TSC2007_ADC_ON_IRQ_DIS0		(0x1 << 2)
+#define TSC2007_ADC_OFF_IRQ_EN		(0x2 << 2)
+#define TSC2007_ADC_ON_IRQ_DIS1		(0x3 << 2)
+
+#define TSC2007_12BIT			(0x0 << 1)
+#define TSC2007_8BIT			(0x1 << 1)
+
+#define	MAX_12BIT			((1 << 12) - 1)
+
+#define ADC_ON_12BIT	(TSC2007_12BIT | TSC2007_ADC_ON_IRQ_DIS0)
+
+#define READ_Y		(ADC_ON_12BIT | TSC2007_MEASURE_Y)
+#define READ_Z1		(ADC_ON_12BIT | TSC2007_MEASURE_Z1)
+#define READ_Z2		(ADC_ON_12BIT | TSC2007_MEASURE_Z2)
+#define READ_X		(ADC_ON_12BIT | TSC2007_MEASURE_X)
+#define PWRDOWN		(TSC2007_12BIT | TSC2007_POWER_OFF_IRQ_EN)
+
+struct ts_event {
+	u16	x;
+	u16	y;
+	u16	z1, z2;
+};
+
+struct tsc2007 {
+	struct input_dev	*input;
+	char			phys[32];
+
+	struct i2c_client	*client;
+
+	u16			model;
+	u16			x_plate_ohms;
+	u16			max_rt;
+	unsigned long		poll_delay;
+	unsigned long		poll_period;
+
+	int			irq;
+
+	wait_queue_head_t	wait;
+	bool			stopped;
+
+	int			(*get_pendown_state)(void);
+	void			(*clear_penirq)(void);
+};
+
+static inline int tsc2007_xfer(struct tsc2007 *tsc, u8 cmd)
+{
+	s32 data;
+	u16 val;
+
+	data = i2c_smbus_read_word_data(tsc->client, cmd);
+	if (data < 0) {
+		dev_err(&tsc->client->dev, "i2c io error: %d\n", data);
+		return data;
+	}
+
+	/* The protocol and raw data format from i2c interface:
+	 * S Addr Wr [A] Comm [A] S Addr Rd [A] [DataLow] A [DataHigh] NA P
+	 * Where DataLow has [D11-D4], DataHigh has [D3-D0 << 4 | Dummy 4bit].
+	 */
+	val = swab16(data) >> 4;
+
+	dev_dbg(&tsc->client->dev, "data: 0x%x, val: 0x%x\n", data, val);
+
+	return val;
+}
+
+static void tsc2007_read_values(struct tsc2007 *tsc, struct ts_event *tc)
+{
+	/* y- still on; turn on only y+ (and ADC) */
+	tc->y = tsc2007_xfer(tsc, READ_Y);
+
+	/* turn y- off, x+ on, then leave in lowpower */
+	tc->x = tsc2007_xfer(tsc, READ_X);
+
+	/* turn y+ off, x- on; we'll use formula #1 */
+	tc->z1 = tsc2007_xfer(tsc, READ_Z1);
+	tc->z2 = tsc2007_xfer(tsc, READ_Z2);
+
+	/* Prepare for next touch reading - power down ADC, enable PENIRQ */
+	tsc2007_xfer(tsc, PWRDOWN);
+}
+
+static u32 tsc2007_calculate_pressure(struct tsc2007 *tsc, struct ts_event *tc)
+{
+	u32 rt = 0;
+
+	/* range filtering */
+	if (tc->x == MAX_12BIT)
+		tc->x = 0;
+
+	if (likely(tc->x && tc->z1)) {
+		/* compute touch pressure resistance using equation #1 */
+		rt = tc->z2 - tc->z1;
+		rt *= tc->x;
+		rt *= tsc->x_plate_ohms;
+		rt /= tc->z1;
+		rt = (rt + 2047) >> 12;
+	}
+
+	return rt;
+}
+
+static bool tsc2007_is_pen_down(struct tsc2007 *ts)
+{
+	/*
+	 * NOTE: We can't rely on the pressure to determine the pen down
+	 * state, even though this controller has a pressure sensor.
+	 * The pressure value can fluctuate for quite a while after
+	 * lifting the pen and in some cases may not even settle at the
+	 * expected value.
+	 *
+	 * The only safe way to check for the pen up condition is in the
+	 * work function by reading the pen signal state (it's a GPIO
+	 * and IRQ). Unfortunately such callback is not always available,
+	 * in that case we assume that the pen is down and expect caller
+	 * to fall back on the pressure reading.
+	 */
+
+	if (!ts->get_pendown_state)
+		return true;
+
+	return ts->get_pendown_state();
+}
+
+static irqreturn_t tsc2007_soft_irq(int irq, void *handle)
+{
+	struct tsc2007 *ts = handle;
+	struct input_dev *input = ts->input;
+	struct ts_event tc;
+	u32 rt;
+
+	while (!ts->stopped && tsc2007_is_pen_down(ts)) {
+
+		/* pen is down, continue with the measurement */
+		tsc2007_read_values(ts, &tc);
+
+		rt = tsc2007_calculate_pressure(ts, &tc);
+
+		if (rt == 0 && !ts->get_pendown_state) {
+			/*
+			 * If pressure reported is 0 and we don't have
+			 * callback to check pendown state, we have to
+			 * assume that pen was lifted up.
+			 */
+			break;
+		}
+
+		if (rt <= ts->max_rt) {
+			dev_dbg(&ts->client->dev,
+				"DOWN point(%4d,%4d), pressure (%4u)\n",
+				tc.x, tc.y, rt);
+
+			input_report_key(input, BTN_TOUCH, 1);
+			input_report_abs(input, ABS_X, tc.x);
+			input_report_abs(input, ABS_Y, tc.y);
+			input_report_abs(input, ABS_PRESSURE, rt);
+
+			input_sync(input);
+
+		} else {
+			/*
+			 * Sample found inconsistent by debouncing or pressure is
+			 * beyond the maximum. Don't report it to user space,
+			 * repeat at least once more the measurement.
+			 */
+			dev_dbg(&ts->client->dev, "ignored pressure %d\n", rt);
+		}
+
+		wait_event_timeout(ts->wait, ts->stopped,
+				   msecs_to_jiffies(ts->poll_period));
+	}
+
+	dev_dbg(&ts->client->dev, "UP\n");
+
+	input_report_key(input, BTN_TOUCH, 0);
+	input_report_abs(input, ABS_PRESSURE, 0);
+	input_sync(input);
+
+	if (ts->clear_penirq)
+		ts->clear_penirq();
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t tsc2007_hard_irq(int irq, void *handle)
+{
+	struct tsc2007 *ts = handle;
+
+	if (!ts->get_pendown_state || likely(ts->get_pendown_state()))
+		return IRQ_WAKE_THREAD;
+
+	if (ts->clear_penirq)
+		ts->clear_penirq();
+
+	return IRQ_HANDLED;
+}
+
+static void tsc2007_stop(struct tsc2007 *ts)
+{
+	ts->stopped = true;
+	mb();
+	wake_up(&ts->wait);
+
+	disable_irq(ts->irq);
+}
+
+static int tsc2007_open(struct input_dev *input_dev)
+{
+	struct tsc2007 *ts = input_get_drvdata(input_dev);
+	int err;
+
+	ts->stopped = false;
+	mb();
+
+	enable_irq(ts->irq);
+
+	/* Prepare for touch readings - power down ADC and enable PENIRQ */
+	err = tsc2007_xfer(ts, PWRDOWN);
+	if (err < 0) {
+		tsc2007_stop(ts);
+		return err;
+	}
+
+	return 0;
+}
+
+static void tsc2007_close(struct input_dev *input_dev)
+{
+	struct tsc2007 *ts = input_get_drvdata(input_dev);
+
+	tsc2007_stop(ts);
+}
+
+static int __devinit tsc2007_probe(struct i2c_client *client,
+				   const struct i2c_device_id *id)
+{
+	struct tsc2007 *ts;
+	struct tsc2007_platform_data *pdata = client->dev.platform_data;
+	struct input_dev *input_dev;
+	int err;
+
+	if (!pdata) {
+		dev_err(&client->dev, "platform data is required!\n");
+		return -EINVAL;
+	}
+
+	if (!i2c_check_functionality(client->adapter,
+				     I2C_FUNC_SMBUS_READ_WORD_DATA))
+		return -EIO;
+
+	ts = kzalloc(sizeof(struct tsc2007), GFP_KERNEL);
+	input_dev = input_allocate_device();
+	if (!ts || !input_dev) {
+		err = -ENOMEM;
+		goto err_free_mem;
+	}
+
+	ts->client = client;
+	ts->irq = client->irq;
+	ts->input = input_dev;
+	init_waitqueue_head(&ts->wait);
+
+	ts->model             = pdata->model;
+	ts->x_plate_ohms      = pdata->x_plate_ohms;
+	ts->max_rt            = pdata->max_rt ? : MAX_12BIT;
+	ts->poll_delay        = pdata->poll_delay ? : 1;
+	ts->poll_period       = pdata->poll_period ? : 1;
+	ts->get_pendown_state = pdata->get_pendown_state;
+	ts->clear_penirq      = pdata->clear_penirq;
+
+	if (pdata->x_plate_ohms == 0) {
+		dev_err(&client->dev, "x_plate_ohms is not set up in platform data");
+		err = -EINVAL;
+		goto err_free_mem;
+	}
+
+	snprintf(ts->phys, sizeof(ts->phys),
+		 "%s/input0", dev_name(&client->dev));
+
+	input_dev->name = "TSC2007 Touchscreen";
+	input_dev->phys = ts->phys;
+	input_dev->id.bustype = BUS_I2C;
+
+	input_dev->open = tsc2007_open;
+	input_dev->close = tsc2007_close;
+
+	input_set_drvdata(input_dev, ts);
+
+	input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
+	input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
+
+	input_set_abs_params(input_dev, ABS_X, 0, MAX_12BIT, pdata->fuzzx, 0);
+	input_set_abs_params(input_dev, ABS_Y, 0, MAX_12BIT, pdata->fuzzy, 0);
+	input_set_abs_params(input_dev, ABS_PRESSURE, 0, MAX_12BIT,
+			pdata->fuzzz, 0);
+
+	if (pdata->init_platform_hw)
+		pdata->init_platform_hw();
+
+	err = request_threaded_irq(ts->irq, tsc2007_hard_irq, tsc2007_soft_irq,
+				   IRQF_ONESHOT, client->dev.driver->name, ts);
+	if (err < 0) {
+		dev_err(&client->dev, "irq %d busy?\n", ts->irq);
+		goto err_free_mem;
+	}
+
+	tsc2007_stop(ts);
+
+	err = input_register_device(input_dev);
+	if (err)
+		goto err_free_irq;
+
+	i2c_set_clientdata(client, ts);
+
+	return 0;
+
+ err_free_irq:
+	free_irq(ts->irq, ts);
+	if (pdata->exit_platform_hw)
+		pdata->exit_platform_hw();
+ err_free_mem:
+	input_free_device(input_dev);
+	kfree(ts);
+	return err;
+}
+
+static int __devexit tsc2007_remove(struct i2c_client *client)
+{
+	struct tsc2007	*ts = i2c_get_clientdata(client);
+	struct tsc2007_platform_data *pdata = client->dev.platform_data;
+
+	free_irq(ts->irq, ts);
+
+	if (pdata->exit_platform_hw)
+		pdata->exit_platform_hw();
+
+	input_unregister_device(ts->input);
+	kfree(ts);
+
+	return 0;
+}
+
+static const struct i2c_device_id tsc2007_idtable[] = {
+	{ "tsc2007", 0 },
+	{ }
+};
+
+MODULE_DEVICE_TABLE(i2c, tsc2007_idtable);
+
+static struct i2c_driver tsc2007_driver = {
+	.driver = {
+		.owner	= THIS_MODULE,
+		.name	= "tsc2007"
+	},
+	.id_table	= tsc2007_idtable,
+	.probe		= tsc2007_probe,
+	.remove		= __devexit_p(tsc2007_remove),
+};
+
+module_i2c_driver(tsc2007_driver);
+
+MODULE_AUTHOR("Kwangwoo Lee <kwlee@mtekvision.com>");
+MODULE_DESCRIPTION("TSC2007 TouchScreen Driver");
+MODULE_LICENSE("GPL");