input: add driver for tnetv107x touchscreen controller

This patch adds support for tnetv107x's on-chip touchscreen controller.

Signed-off-by: Cyril Chemparathy <cyril@ti.com>
Acked-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>

1 files changed, 396 insertions, 0 deletions

diff --git a/drivers/input/touchscreen/tnetv107x-ts.c b/drivers/input/touchscreen/tnetv107x-ts.c
new file mode 100644
index 000000000000..cf1dba2e267c
--- /dev/null
+++ b/drivers/input/touchscreen/tnetv107x-ts.c
@@ -0,0 +1,396 @@
+/*
+ * Texas Instruments TNETV107X Touchscreen Driver
+ *
+ * Copyright (C) 2010 Texas Instruments
+ *
+ * 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 version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/input.h>
+#include <linux/platform_device.h>
+#include <linux/interrupt.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/ctype.h>
+#include <linux/io.h>
+#include <linux/clk.h>
+
+#include <mach/tnetv107x.h>
+
+#define TSC_PENUP_POLL		(HZ / 5)
+#define IDLE_TIMEOUT		100 /* msec */
+
+/*
+ * The first and last samples of a touch interval are usually garbage and need
+ * to be filtered out with these devices.  The following definitions control
+ * the number of samples skipped.
+ */
+#define TSC_HEAD_SKIP		1
+#define TSC_TAIL_SKIP		1
+#define TSC_SKIP		(TSC_HEAD_SKIP + TSC_TAIL_SKIP + 1)
+#define TSC_SAMPLES		(TSC_SKIP + 1)
+
+/* Register Offsets */
+struct tsc_regs {
+	u32	rev;
+	u32	tscm;
+	u32	bwcm;
+	u32	swc;
+	u32	adcchnl;
+	u32	adcdata;
+	u32	chval[4];
+};
+
+/* TSC Mode Configuration Register (tscm) bits */
+#define WMODE		BIT(0)
+#define TSKIND		BIT(1)
+#define ZMEASURE_EN	BIT(2)
+#define IDLE		BIT(3)
+#define TSC_EN		BIT(4)
+#define STOP		BIT(5)
+#define ONE_SHOT	BIT(6)
+#define SINGLE		BIT(7)
+#define AVG		BIT(8)
+#define AVGNUM(x)	(((x) & 0x03) <<  9)
+#define PVSTC(x)	(((x) & 0x07) << 11)
+#define PON		BIT(14)
+#define PONBG		BIT(15)
+#define AFERST		BIT(16)
+
+/* ADC DATA Capture Register bits */
+#define DATA_VALID	BIT(16)
+
+/* Register Access Macros */
+#define tsc_read(ts, reg)		__raw_readl(&(ts)->regs->reg)
+#define tsc_write(ts, reg, val)		__raw_writel(val, &(ts)->regs->reg);
+#define tsc_set_bits(ts, reg, val)	\
+	tsc_write(ts, reg, tsc_read(ts, reg) | (val))
+#define tsc_clr_bits(ts, reg, val)	\
+	tsc_write(ts, reg, tsc_read(ts, reg) & ~(val))
+
+struct sample {
+	int x, y, p;
+};
+
+struct tsc_data {
+	struct input_dev		*input_dev;
+	struct resource			*res;
+	struct tsc_regs __iomem		*regs;
+	struct timer_list		timer;
+	spinlock_t			lock;
+	struct clk			*clk;
+	struct device			*dev;
+	int				sample_count;
+	struct sample			samples[TSC_SAMPLES];
+	int				tsc_irq;
+};
+
+static int tsc_read_sample(struct tsc_data *ts, struct sample* sample)
+{
+	int	x, y, z1, z2, t, p = 0;
+	u32	val;
+
+	val = tsc_read(ts, chval[0]);
+	if (val & DATA_VALID)
+		x = val & 0xffff;
+	else
+		return -EINVAL;
+
+	y  = tsc_read(ts, chval[1]) & 0xffff;
+	z1 = tsc_read(ts, chval[2]) & 0xffff;
+	z2 = tsc_read(ts, chval[3]) & 0xffff;
+
+	if (z1) {
+		t = ((600 * x) * (z2 - z1));
+		p = t / (u32) (z1 << 12);
+		if (p < 0)
+			p = 0;
+	}
+
+	sample->x  = x;
+	sample->y  = y;
+	sample->p  = p;
+
+	return 0;
+}
+
+static void tsc_poll(unsigned long data)
+{
+	struct tsc_data *ts = (struct tsc_data *)data;
+	unsigned long flags;
+	int i, val, x, y, p;
+
+	spin_lock_irqsave(&ts->lock, flags);
+
+	if (ts->sample_count >= TSC_SKIP) {
+		input_report_abs(ts->input_dev, ABS_PRESSURE, 0);
+		input_report_key(ts->input_dev, BTN_TOUCH, 0);
+		input_sync(ts->input_dev);
+	} else if (ts->sample_count > 0) {
+		/*
+		 * A touch event lasted less than our skip count.  Salvage and
+		 * report anyway.
+		 */
+		for (i = 0, val = 0; i < ts->sample_count; i++)
+			val += ts->samples[i].x;
+		x = val / ts->sample_count;
+
+		for (i = 0, val = 0; i < ts->sample_count; i++)
+			val += ts->samples[i].y;
+		y = val / ts->sample_count;
+
+		for (i = 0, val = 0; i < ts->sample_count; i++)
+			val += ts->samples[i].p;
+		p = val / ts->sample_count;
+
+		input_report_abs(ts->input_dev, ABS_X, x);
+		input_report_abs(ts->input_dev, ABS_Y, y);
+		input_report_abs(ts->input_dev, ABS_PRESSURE, p);
+		input_report_key(ts->input_dev, BTN_TOUCH, 1);
+		input_sync(ts->input_dev);
+	}
+
+	ts->sample_count = 0;
+
+	spin_unlock_irqrestore(&ts->lock, flags);
+}
+
+static irqreturn_t tsc_irq(int irq, void *dev_id)
+{
+	struct tsc_data *ts = (struct tsc_data *)dev_id;
+	struct sample *sample;
+	int index;
+
+	spin_lock(&ts->lock);
+
+	index = ts->sample_count % TSC_SAMPLES;
+	sample = &ts->samples[index];
+	if (tsc_read_sample(ts, sample) < 0)
+		goto out;
+
+	if (++ts->sample_count >= TSC_SKIP) {
+		index = (ts->sample_count - TSC_TAIL_SKIP - 1) % TSC_SAMPLES;
+		sample = &ts->samples[index];
+
+		input_report_abs(ts->input_dev, ABS_X, sample->x);
+		input_report_abs(ts->input_dev, ABS_Y, sample->y);
+		input_report_abs(ts->input_dev, ABS_PRESSURE, sample->p);
+		if (ts->sample_count == TSC_SKIP)
+			input_report_key(ts->input_dev, BTN_TOUCH, 1);
+		input_sync(ts->input_dev);
+	}
+	mod_timer(&ts->timer, jiffies + TSC_PENUP_POLL);
+out:
+	spin_unlock(&ts->lock);
+	return IRQ_HANDLED;
+}
+
+static int tsc_start(struct input_dev *dev)
+{
+	struct tsc_data *ts = input_get_drvdata(dev);
+	unsigned long timeout = jiffies + msecs_to_jiffies(IDLE_TIMEOUT);
+	u32 val;
+
+	clk_enable(ts->clk);
+
+	/* Go to idle mode, before any initialization */
+	while (time_after(timeout, jiffies)) {
+		if (tsc_read(ts, tscm) & IDLE)
+			break;
+	}
+
+	if (time_before(timeout, jiffies)) {
+		dev_warn(ts->dev, "timeout waiting for idle\n");
+		clk_disable(ts->clk);
+		return -EIO;
+	}
+
+	/* Configure TSC Control register*/
+	val = (PONBG | PON | PVSTC(4) | ONE_SHOT | ZMEASURE_EN);
+	tsc_write(ts, tscm, val);
+
+	/* Bring TSC out of reset: Clear AFE reset bit */
+	val &= ~(AFERST);
+	tsc_write(ts, tscm, val);
+
+	/* Configure all pins for hardware control*/
+	tsc_write(ts, bwcm, 0);
+
+	/* Finally enable the TSC */
+	tsc_set_bits(ts, tscm, TSC_EN);
+
+	return 0;
+}
+
+static void tsc_stop(struct input_dev *dev)
+{
+	struct tsc_data *ts = input_get_drvdata(dev);
+
+	tsc_clr_bits(ts, tscm, TSC_EN);
+	synchronize_irq(ts->tsc_irq);
+	del_timer_sync(&ts->timer);
+	clk_disable(ts->clk);
+}
+
+static int __devinit tsc_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct tsc_data *ts;
+	int error = 0;
+	u32 rev = 0;
+
+	ts = kzalloc(sizeof(struct tsc_data), GFP_KERNEL);
+	if (!ts) {
+		dev_err(dev, "cannot allocate device info\n");
+		return -ENOMEM;
+	}
+
+	ts->dev = dev;
+	spin_lock_init(&ts->lock);
+	setup_timer(&ts->timer, tsc_poll, (unsigned long)ts);
+	platform_set_drvdata(pdev, ts);
+
+	ts->tsc_irq = platform_get_irq(pdev, 0);
+	if (ts->tsc_irq < 0) {
+		dev_err(dev, "cannot determine device interrupt\n");
+		error = -ENODEV;
+		goto error_res;
+	}
+
+	ts->res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!ts->res) {
+		dev_err(dev, "cannot determine register area\n");
+		error = -ENODEV;
+		goto error_res;
+	}
+
+	if (!request_mem_region(ts->res->start, resource_size(ts->res),
+				pdev->name)) {
+		dev_err(dev, "cannot claim register memory\n");
+		ts->res = NULL;
+		error = -EINVAL;
+		goto error_res;
+	}
+
+	ts->regs = ioremap(ts->res->start, resource_size(ts->res));
+	if (!ts->regs) {
+		dev_err(dev, "cannot map register memory\n");
+		error = -ENOMEM;
+		goto error_map;
+	}
+
+	ts->clk = clk_get(dev, NULL);
+	if (!ts->clk) {
+		dev_err(dev, "cannot claim device clock\n");
+		error = -EINVAL;
+		goto error_clk;
+	}
+
+	error = request_threaded_irq(ts->tsc_irq, NULL, tsc_irq, 0,
+				     dev_name(dev), ts);
+	if (error < 0) {
+		dev_err(ts->dev, "Could not allocate ts irq\n");
+		goto error_irq;
+	}
+
+	ts->input_dev = input_allocate_device();
+	if (!ts->input_dev) {
+		dev_err(dev, "cannot allocate input device\n");
+		error = -ENOMEM;
+		goto error_input;
+	}
+	input_set_drvdata(ts->input_dev, ts);
+
+	ts->input_dev->name       = pdev->name;
+	ts->input_dev->id.bustype = BUS_HOST;
+	ts->input_dev->dev.parent = &pdev->dev;
+	ts->input_dev->open	  = tsc_start;
+	ts->input_dev->close	  = tsc_stop;
+
+	clk_enable(ts->clk);
+	rev = tsc_read(ts, rev);
+	ts->input_dev->id.product = ((rev >>  8) & 0x07);
+	ts->input_dev->id.version = ((rev >> 16) & 0xfff);
+	clk_disable(ts->clk);
+
+	__set_bit(EV_KEY,    ts->input_dev->evbit);
+	__set_bit(EV_ABS,    ts->input_dev->evbit);
+	__set_bit(BTN_TOUCH, ts->input_dev->keybit);
+
+	input_set_abs_params(ts->input_dev, ABS_X, 0, 0xffff, 5, 0);
+	input_set_abs_params(ts->input_dev, ABS_Y, 0, 0xffff, 5, 0);
+	input_set_abs_params(ts->input_dev, ABS_PRESSURE, 0, 4095, 128, 0);
+
+	error = input_register_device(ts->input_dev);
+	if (error < 0) {
+		dev_err(dev, "failed input device registration\n");
+		goto error_reg;
+	}
+
+	return 0;
+
+error_reg:
+	input_free_device(ts->input_dev);
+error_input:
+	free_irq(ts->tsc_irq, ts);
+error_irq:
+	clk_put(ts->clk);
+error_clk:
+	iounmap(ts->regs);
+error_map:
+	release_mem_region(ts->res->start, resource_size(ts->res));
+error_res:
+	platform_set_drvdata(pdev, NULL);
+	kfree(ts);
+
+	return error;
+}
+
+static int __devexit tsc_remove(struct platform_device *pdev)
+{
+	struct tsc_data *ts = platform_get_drvdata(pdev);
+
+	input_unregister_device(ts->input_dev);
+	free_irq(ts->tsc_irq, ts);
+	clk_put(ts->clk);
+	iounmap(ts->regs);
+	release_mem_region(ts->res->start, resource_size(ts->res));
+	platform_set_drvdata(pdev, NULL);
+	kfree(ts);
+
+	return 0;
+}
+
+static struct platform_driver tsc_driver = {
+	.probe		= tsc_probe,
+	.remove		= __devexit_p(tsc_remove),
+	.driver.name	= "tnetv107x-ts",
+	.driver.owner	= THIS_MODULE,
+};
+
+static int __init tsc_init(void)
+{
+	return platform_driver_register(&tsc_driver);
+}
+
+static void __exit tsc_exit(void)
+{
+	platform_driver_unregister(&tsc_driver);
+}
+
+module_init(tsc_init);
+module_exit(tsc_exit);
+
+MODULE_AUTHOR("Cyril Chemparathy");
+MODULE_DESCRIPTION("TNETV107X Touchscreen Driver");
+MODULE_ALIAS("platform: tnetv107x-ts");
+MODULE_LICENSE("GPL");