[PATCH 5/7] input: add driver for tnetv107x touchscreen controller

[Cyril Chemparathy <cyril@ti.com>]

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

Signed-off-by: Cyril Chemparathy <cyril@ti.com>
---
 drivers/input/touchscreen/Kconfig        |    6 +
 drivers/input/touchscreen/Makefile       |    1 +
 drivers/input/touchscreen/tnetv107x-ts.c |  481 ++++++++++++++++++++++++++++++
 3 files changed, 488 insertions(+), 0 deletions(-)
 create mode 100644 drivers/input/touchscreen/tnetv107x-ts.c

diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index 0069d97..e56a170 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -638,4 +638,10 @@ config TOUCHSCREEN_STMPE
 	  To compile this driver as a module, choose M here: the
 	  module will be called stmpe-ts.
 
+config TOUCHSCREEN_TNETV107X
+	tristate "TI TNETV107X touchscreen support"
+	depends on ARCH_DAVINCI_TNETV107X
+	help
+	  Say Y here if you want to use the TNETV107X touchscreen.
+
 endif
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index 28217e1..55a7db9 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -52,3 +52,4 @@ obj-$(CONFIG_TOUCHSCREEN_WM97XX_MAINSTONE)	+= mainstone-wm97xx.o
 obj-$(CONFIG_TOUCHSCREEN_WM97XX_ZYLONITE)	+= zylonite-wm97xx.o
 obj-$(CONFIG_TOUCHSCREEN_W90X900)	+= w90p910_ts.o
 obj-$(CONFIG_TOUCHSCREEN_TPS6507X)	+= tps6507x-ts.o
+obj-$(CONFIG_TOUCHSCREEN_TNETV107X)	+= tnetv107x-ts.o
diff --git a/drivers/input/touchscreen/tnetv107x-ts.c b/drivers/input/touchscreen/tnetv107x-ts.c
new file mode 100644
index 0000000..a8543c5
--- /dev/null
+++ b/drivers/input/touchscreen/tnetv107x-ts.c
@@ -0,0 +1,481 @@
+/*
+ * 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>
+
+/* Poll Rates */
+#define TSC_PENUP_POLL		(HZ / 5)
+
+/*
+ * 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 tnetv107x_tsc_data	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;
+	int				cal[TSC_CAL_SIZE];
+};
+
+/* default calibration that works for most evm boards */
+static int tscal_set;
+static int tscal[TSC_CAL_SIZE];
+module_param_array(tscal, int, &tscal_set, 0);
+
+static inline 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  = (ts->cal[2] + ts->cal[0] * x + ts->cal[1] * y);
+	sample->x /= ts->cal[6];
+	sample->y  = (ts->cal[5] + ts->cal[3] * x + ts->cal[4] * y);
+	sample->y /= ts->cal[6];
+	sample->p  = p;
+
+	return 0;
+}
+
+static inline void tsc_report_up(struct tsc_data *ts)
+{
+	input_report_abs(ts->input_dev, ABS_PRESSURE, 0);
+	input_report_key(ts->input_dev, BTN_TOUCH, 0);
+	input_sync(ts->input_dev);
+}
+
+static inline void tsc_report(struct tsc_data *ts, int x, int y, int p)
+{
+	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);
+}
+
+static inline void tsc_report_down(struct tsc_data *ts, bool touch)
+{
+	if (touch)
+		input_report_key(ts->input_dev, BTN_TOUCH, 1);
+	input_sync(ts->input_dev);
+}
+
+static inline 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) {
+		tsc_report_up(ts);
+	} 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;
+
+		tsc_report(ts, x, y, p);
+		tsc_report_down(ts, true);
+	}
+
+	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) {
+		++ts->sample_count;
+
+		if (ts->sample_count < TSC_SKIP)
+			goto done;
+
+		index = (ts->sample_count - TSC_TAIL_SKIP - 1) % TSC_SAMPLES;
+		sample = &ts->samples[index];
+
+		tsc_report(ts, sample->x, sample->y, sample->y);
+		tsc_report_down(ts, (ts->sample_count == TSC_SKIP));
+done:
+		mod_timer(&ts->timer, jiffies + TSC_PENUP_POLL);
+	}
+
+	spin_unlock(&ts->lock);
+	return IRQ_HANDLED;
+}
+
+static ssize_t tsc_cal_show(struct device *dev, struct device_attribute *attr,
+			    char *buf)
+{
+	struct tsc_data *ts = dev_get_drvdata(dev);
+	ssize_t len = 0;
+	int i;
+
+	for (i = 0; i < 6; i++)
+		len += snprintf(buf+len, PAGE_SIZE-len, "%d ", ts->cal[i]);
+
+	len += snprintf(buf+len, PAGE_SIZE-len, "%d\n", ts->cal[6]);
+
+	return len;
+}
+
+/*
+ * The calibration data format is identical to the contents of tslib's
+ * generated output
+ */
+static ssize_t tsc_cal_store(struct device *dev, struct device_attribute *attr,
+			     const char *buf, size_t count)
+{
+	struct tsc_data *ts = dev_get_drvdata(dev);
+	int index = 0;
+	int cal[TSC_CAL_SIZE];
+	const char *cur = buf, *end = buf + count;
+	char *tmp;
+	unsigned long flags;
+
+	for (index = 0; index < TSC_CAL_SIZE; index++) {
+		while (isspace(*cur) && cur < end)
+			cur++;
+		if (cur >= end) {
+			dev_err(ts->dev, "premature end in calib data\n");
+			return -EINVAL;
+		}
+
+		if (isdigit(*cur) || *cur == '-') {
+			cal[index] = simple_strtol(cur, &tmp, 0);
+			cur = tmp;
+		}
+	}
+
+	spin_lock_irqsave(&ts->lock, flags);
+	memcpy(ts->cal, cal, sizeof(cal));
+	spin_unlock_irqrestore(&ts->lock, flags);
+
+	return count;
+}
+
+static struct device_attribute tsc_attr_cal =
+	__ATTR(tscal, S_IWUSR | S_IRUGO, tsc_cal_show, tsc_cal_store);
+
+static int tsc_probe(struct platform_device *pdev)
+{
+	struct tnetv107x_tsc_data *pdata = pdev->dev.platform_data;
+	struct tsc_data *ts;
+	int ret = 0, *cal;
+	u32 rev = 0, val = 0;
+	struct device *dev = &pdev->dev;
+
+	if (!pdata) {
+		dev_err(dev, "could not find platform data\n");
+		return -EINVAL;
+	}
+
+	ts = kzalloc(sizeof(struct tsc_data), GFP_KERNEL);
+	if (!ts) {
+		dev_err(dev, "cannot allocate device info\n");
+		return -ENOMEM;
+	}
+
+	ts->dev = dev;
+	ts->data = *pdata;
+	dev_set_drvdata(dev, ts);
+
+	cal = (tscal_set == TSC_CAL_SIZE) ? tscal : ts->data.calibration_data;
+	memcpy(ts->cal, cal, TSC_CAL_SIZE * sizeof(int));
+
+	ret = -ENOMEM;
+	ts->input_dev = input_allocate_device();
+	if (!ts->input_dev) {
+		dev_err(dev, "cannot allocate input device\n");
+		goto error0;
+	}
+
+	ret = -ENODEV;
+	ts->tsc_irq = platform_get_irq(pdev, 0);
+	if (ts->tsc_irq < 0) {
+		dev_err(dev, "cannot determine device interrupt\n");
+		goto error1;
+	}
+
+	ret = -ENODEV;
+	ts->res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!ts->res) {
+		dev_err(dev, "cannot determine register area\n");
+		goto error1;
+	}
+
+	ret = -EINVAL;
+	if (!request_mem_region(ts->res->start, resource_size(ts->res),
+				pdev->name)) {
+		dev_err(dev, "cannot claim register memory\n");
+		goto error1;
+	}
+
+	ret = -ENOMEM;
+	ts->regs = ioremap(ts->res->start, resource_size(ts->res));
+	if (!ts->regs) {
+		dev_err(dev, "cannot map register memory\n");
+		goto error2;
+	}
+
+	ret = -EINVAL;
+	ts->clk = clk_get(dev, NULL);
+	if (!ts->clk) {
+		dev_err(dev, "cannot claim device clock\n");
+		goto error3;
+	}
+	clk_enable(ts->clk);
+
+	spin_lock_init(&ts->lock);
+
+	init_timer(&ts->timer);
+	setup_timer(&ts->timer, tsc_poll, (unsigned long)ts);
+
+	/* Go to idle mode, before any initialization */
+	while ((tsc_read(ts, tscm) & IDLE) == 0)
+		barrier();
+
+	/* Configure the 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);
+	udelay(10);
+
+	/* Configure all pins for hardware control*/
+	tsc_write(ts, bwcm, 0);
+
+	/* Finally enable the TSC */
+	tsc_set_bits(ts, tscm, TSC_EN);
+
+	ret = -EINVAL;
+	if (request_irq(ts->tsc_irq, tsc_irq, 0, "tnetv107x-ts", ts)) {
+		dev_err(dev, "Could not allocate ts irq\n");
+		goto error4;
+	}
+
+	ret = device_create_file(ts->dev, &tsc_attr_cal);
+	if (ret < 0) {
+		dev_err(dev, "Could not create sysfs entry!\n");
+		goto error5;
+	}
+
+	rev = tsc_read(ts, rev);
+	ts->input_dev->name       = "tnetv107x-ts";
+	ts->input_dev->phys       = "tnetv107x-ts/input0";
+	ts->input_dev->id.bustype = BUS_HOST;
+	ts->input_dev->id.vendor  = 0x0001;
+	ts->input_dev->id.product = ((rev >>  8) & 0x07);
+	ts->input_dev->id.version = ((rev >> 16) & 0xfff);
+	ts->input_dev->dev.parent = &pdev->dev;
+
+	/* Declare capabilities */
+	set_bit(EV_KEY,       ts->input_dev->evbit);
+	set_bit(BTN_TOUCH,    ts->input_dev->keybit);
+	set_bit(EV_ABS,       ts->input_dev->evbit);
+	set_bit(ABS_X,        ts->input_dev->absbit);
+	set_bit(ABS_Y,        ts->input_dev->absbit);
+	set_bit(ABS_PRESSURE, ts->input_dev->absbit);
+
+	input_set_abs_params(ts->input_dev, ABS_X, 0, ts->data.xres, 5, 0);
+	input_set_abs_params(ts->input_dev, ABS_Y, 0, ts->data.yres, 5, 0);
+	input_set_abs_params(ts->input_dev, ABS_PRESSURE, 0, 4095, 128, 0);
+
+	ret = input_register_device(ts->input_dev);
+	if (ret < 0)
+		goto error6;
+
+	return 0;
+
+error6:
+	device_remove_file(ts->dev, &tsc_attr_cal);
+error5:
+	free_irq(ts->tsc_irq, ts);
+error4:
+	clk_disable(ts->clk);
+	clk_put(ts->clk);
+error3:
+	iounmap(ts->regs);
+error2:
+	release_mem_region(ts->res->start, resource_size(ts->res));
+error1:
+	input_free_device(ts->input_dev);
+error0:
+	kfree(ts);
+	dev_set_drvdata(dev, NULL);
+	return ret;
+}
+
+static int tsc_remove(struct platform_device *pdev)
+{
+	struct tsc_data *ts = dev_get_drvdata(&pdev->dev);
+
+	if (!ts)
+		return 0;
+
+	tsc_clr_bits(ts, tscm, TSC_EN);
+	del_timer_sync(&ts->timer);
+	device_remove_file(ts->dev, &tsc_attr_cal);
+	free_irq(ts->tsc_irq, ts);
+	clk_disable(ts->clk);
+	clk_put(ts->clk);
+	iounmap(ts->regs);
+	release_mem_region(ts->res->start, resource_size(ts->res));
+	input_free_device(ts->input_dev);
+	kfree(ts);
+	dev_set_drvdata(&pdev->dev, NULL);
+	return 0;
+}
+
+static int tsc_suspend(struct platform_device *pdev, pm_message_t state)
+{
+	/* Nothing yet */
+	return 0;
+}
+
+static int tsc_resume(struct platform_device *pdev)
+{
+	/* Nothing yet */
+	return 0;
+}
+
+static struct platform_driver tsc_driver = {
+	.probe		= tsc_probe,
+	.remove		= tsc_remove,
+	.suspend	= tsc_suspend,
+	.resume		= tsc_resume,
+	.driver.name	= "tnetv107x-ts",
+};
+
+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_DESCRIPTION("TNETV107X Touchscreen Driver");
+MODULE_LICENSE("GPL");
-- 
1.7.0.4