[patch 1/1] TOUCHSCREEN: S3C24XX touchscreen driver from Arnaud Patard.

[Ben Dooks <ben@simtec.co.uk>]

[-- Attachment #1: thirdparty/inprogress/s3c24xx-touchscreen.patch --]
[-- Type: TEXT/PLAIN, Size: 15952 bytes --]

From: Arnaud Patard <arnaud.patard@rtp-net.org>

S3C24XX touchscreen driver, originally written by Arnaud Patard and
other contributors. This driver is the version from the Simtec Electronics
tree, and as such is the best place to start and thus proposed to be
merged into the linux input system.

The driver has had substantial testing as well as a number of tidying
up passes done by Ben Dooks, as noted:

- added kernel-doc comments to most of the routines
- removed old code from pre adc framework days
- updated device probe code to use platform id list matching
- cleaned up debug, since printk() now has timestamp feature
- ensure code uses dev_() reporting macros where necessary

Signed-off-by: Arnaud Patard <arnaud.patard@rtp-net.org>
Signed-off-by: Simtec Linux Team <linux@simtec.co.uk>
Signed-off-by: Ben Dooks <ben@simtec.co.uk>

---
 drivers/input/touchscreen/Kconfig      |   18 +
 drivers/input/touchscreen/Makefile     |    1 
 drivers/input/touchscreen/s3c2410_ts.c |  464 +++++++++++++++++++++++++++++++++
 3 files changed, 483 insertions(+)


Index: b/drivers/input/touchscreen/Kconfig
===================================================================
--- a/drivers/input/touchscreen/Kconfig	2009-11-09 22:28:23.000000000 +0000
+++ b/drivers/input/touchscreen/Kconfig	2009-11-10 10:38:44.000000000 +0000
@@ -133,6 +133,24 @@ config TOUCHSCREEN_FUJITSU
 	  To compile this driver as a module, choose M here: the
 	  module will be called fujitsu-ts.
 
+config TOUCHSCREEN_S3C2410
+	tristate "Samsung S3C2410 touchscreen input driver"
+	depends on ARCH_S3C2410 && INPUT && INPUT_TOUCHSCREEN
+	select SERIO
+	help
+	  Say Y here if you have the s3c2410 touchscreen.
+
+	  If unsure, say N.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called s3c2410_ts.
+
+config TOUCHSCREEN_S3C2410_DEBUG
+	boolean "Samsung S3C2410 touchscreen debug messages"
+	depends on TOUCHSCREEN_S3C2410
+	help
+	  Select this if you want debug messages
+
 config TOUCHSCREEN_GUNZE
 	tristate "Gunze AHL-51S touchscreen"
 	select SERIO
Index: b/drivers/input/touchscreen/Makefile
===================================================================
--- a/drivers/input/touchscreen/Makefile	2009-11-09 22:28:23.000000000 +0000
+++ b/drivers/input/touchscreen/Makefile	2009-11-10 10:38:44.000000000 +0000
@@ -26,6 +26,7 @@ obj-$(CONFIG_TOUCHSCREEN_HP7XX)		+= jorn
 obj-$(CONFIG_TOUCHSCREEN_HTCPEN)	+= htcpen.o
 obj-$(CONFIG_TOUCHSCREEN_USB_COMPOSITE)	+= usbtouchscreen.o
 obj-$(CONFIG_TOUCHSCREEN_PENMOUNT)	+= penmount.o
+obj-$(CONFIG_TOUCHSCREEN_S3C2410)	+= s3c2410_ts.o
 obj-$(CONFIG_TOUCHSCREEN_TOUCHIT213)	+= touchit213.o
 obj-$(CONFIG_TOUCHSCREEN_TOUCHRIGHT)	+= touchright.o
 obj-$(CONFIG_TOUCHSCREEN_TOUCHWIN)	+= touchwin.o
Index: b/drivers/input/touchscreen/s3c2410_ts.c
===================================================================
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ b/drivers/input/touchscreen/s3c2410_ts.c	2009-11-10 10:47:38.000000000 +0000
@@ -0,0 +1,464 @@
+/* drivers/input/touchscreen/s3c2410_ts.c
+ *
+ * Samsung S3C24XX touchscreen driver
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the term of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * Copyright 2004 Arnaud Patard <arnaud.patard@rtp-net.org>
+ * Copyright 2008 Ben Dooks <ben-linux@fluff.org>
+ * Copyright 2009 Simtec Electronics <linux@simtec.co.uk>
+ *
+ * Additional work by Herbert Pötzl <herbert@13thfloor.at> and
+ * Harald Welte <laforge@openmoko.org>
+ */
+
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/gpio.h>
+#include <linux/input.h>
+#include <linux/init.h>
+#include <linux/serio.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+
+#include <plat/adc.h>
+#include <plat/regs-adc.h>
+
+#include <mach/regs-gpio.h>
+#include <mach/ts.h>
+
+/* For ts.dev.id.version */
+#define S3C2410TSVERSION	0x0101
+
+#define TSC_SLEEP  (S3C2410_ADCTSC_PULL_UP_DISABLE | S3C2410_ADCTSC_XY_PST(0))
+
+#define INT_DOWN	(0)
+#define INT_UP		(1 << 8)
+
+#define WAIT4INT	(S3C2410_ADCTSC_YM_SEN | \
+			 S3C2410_ADCTSC_YP_SEN | \
+			 S3C2410_ADCTSC_XP_SEN | \
+			 S3C2410_ADCTSC_XY_PST(3))
+
+#define AUTOPST		(S3C2410_ADCTSC_YM_SEN | \
+			 S3C2410_ADCTSC_YP_SEN | \
+			 S3C2410_ADCTSC_XP_SEN | \
+			 S3C2410_ADCTSC_AUTO_PST | \
+			 S3C2410_ADCTSC_XY_PST(0))
+
+#define DEBUG_LVL    KERN_DEBUG
+
+static char *s3c2410ts_name = "s3c2410 TouchScreen";
+
+/* Per-touchscreen data. */
+
+/**
+ * struct s3c2410ts - driver touchscreen state.
+ * @client: The ADC client we registered with the core driver.
+ * @dev: The device we are bound to.
+ * @input: The input device we registered with the input subsystem.
+ * @clock: The clock for the adc.
+ * @io: Pointer to the IO base.
+ * @xp: The accumulated X position data.
+ * @yp: The accumulated Y position data.
+ * @irq_tc: The interrupt number for pen up/down interrupt
+ * @count: The number of samples collected.
+ * @shift: The log2 of the maximum count to read in one go.
+ */
+struct s3c2410ts {
+	struct s3c_adc_client *client;
+	struct device *dev;
+	struct input_dev *input;
+	struct clk *clock;
+	void __iomem *io;
+	unsigned long xp;
+	unsigned long yp;
+	int irq_tc;
+	int count;
+	int shift;
+};
+
+static struct s3c2410ts ts;
+
+/**
+ * s3c2410_ts_connect - configure gpio for s3c2410 systems
+ *
+ * Configure the GPIO for the S3C2410 system, where we have external FETs
+ * connected to the device (later systems such as the S3C2440 integrate
+ * these into the device).
+*/
+static inline void s3c2410_ts_connect(void)
+{
+	s3c2410_gpio_cfgpin(S3C2410_GPG(12), S3C2410_GPG12_XMON);
+	s3c2410_gpio_cfgpin(S3C2410_GPG(13), S3C2410_GPG13_nXPON);
+	s3c2410_gpio_cfgpin(S3C2410_GPG(14), S3C2410_GPG14_YMON);
+	s3c2410_gpio_cfgpin(S3C2410_GPG(15), S3C2410_GPG15_nYPON);
+}
+
+/**
+ * get_down - return the down state of the pen
+ * @data0: The data read from ADCDAT0 register.
+ * @data1: The data read from ADCDAT1 register.
+ *
+ * Return non-zero if both readings show that the pen is down.
+ */
+static inline int get_down(unsigned long data0, unsigned long data1)
+{
+	/* returns true if both data values show stylus down */
+	return (!(data0 & S3C2410_ADCDAT0_UPDOWN) &&
+		!(data1 & S3C2410_ADCDAT0_UPDOWN));
+}
+
+static void touch_timer_fire(unsigned long data)
+{
+	unsigned long data0;
+	unsigned long data1;
+	int down;
+
+	data0 = readl(ts.io + S3C2410_ADCDAT0);
+	data1 = readl(ts.io + S3C2410_ADCDAT1);
+
+	down = get_down(data0, data1);
+
+	if (ts.count == (1<<ts.shift)) {
+		ts.xp >>= ts.shift;
+		ts.yp >>= ts.shift;
+
+		dev_dbg(ts.dev, "%s: X=%lu, Y=%lu, count=%d\n",
+			__func__, ts.xp, ts.yp, ts.count);
+
+		input_report_abs(ts.input, ABS_X, ts.xp);
+		input_report_abs(ts.input, ABS_Y, ts.yp);
+
+		input_report_key(ts.input, BTN_TOUCH, 1);
+		input_report_abs(ts.input, ABS_PRESSURE, 1);
+		input_sync(ts.input);
+
+		ts.xp = 0;
+		ts.yp = 0;
+		ts.count = 0;
+	}
+
+	if (down) {
+		s3c_adc_start(ts.client, 0, 1 << ts.shift);
+	} else {
+		ts.count = 0;
+
+		input_report_key(ts.input, BTN_TOUCH, 0);
+		input_report_abs(ts.input, ABS_PRESSURE, 0);
+		input_sync(ts.input);
+
+		writel(WAIT4INT | INT_DOWN, ts.io + S3C2410_ADCTSC);
+	}
+}
+
+static struct timer_list touch_timer = TIMER_INITIALIZER(touch_timer_fire, 0, 0);
+
+/**
+ * stylus_irq - touchscreen stylus event interrupt
+ * @irq: The interrupt number
+ * @dev_id: The device ID.
+ *
+ * Called when the IRQ_TC is fired for a pen up or down event.
+ */
+static irqreturn_t stylus_irq(int irq, void *dev_id)
+{
+	unsigned long data0;
+	unsigned long data1;
+	int down;
+
+	data0 = readl(ts.io + S3C2410_ADCDAT0);
+	data1 = readl(ts.io + S3C2410_ADCDAT1);
+
+	down = get_down(data0, data1);
+
+	/* TODO we should never get an interrupt with down set while
+	 * the timer is running, but maybe we ought to verify that the
+	 * timer isn't running anyways. */
+
+	if (down)
+		s3c_adc_start(ts.client, 0, 1 << ts.shift);
+	else
+		dev_info(ts.dev, "%s: count=%d\n", __func__, ts.count);
+
+	return IRQ_HANDLED;
+}
+
+/**
+ * s3c24xx_ts_conversion - ADC conversion callback
+ * @client: The client that was registered with the ADC core.
+ * @data0: The reading from ADCDAT0.
+ * @data1: The reading from ADCDAT1.
+ * @left: The number of samples left.
+ *
+ * Called when a conversion has finished.
+ */
+static void s3c24xx_ts_conversion(struct s3c_adc_client *client,
+				  unsigned data0, unsigned data1,
+				  unsigned *left)
+{
+	dev_dbg(ts.dev, "%s: %d,%d\n", __func__, data0, data1);
+
+	ts.xp += data0;
+	ts.yp += data1;
+
+	ts.count++;
+
+	/* From tests, it seems that it is unlikely to get a pen-up
+	 * event during the conversion process which means we can
+	 * ignore any pen-up events with less than the requisite
+	 * count done.
+	 *
+	 * In several thousand conversions, no pen-ups where detected
+	 * before count completed.
+	 */
+}
+
+/**
+ * s3c24xx_ts_select - ADC selection callback.
+ * @client: The client that was registered with the ADC core.
+ * @select: The reason for select.
+ *
+ * Called when the ADC core selects (or deslects) us as a client.
+ */
+static void s3c24xx_ts_select(struct s3c_adc_client *client, unsigned select)
+{
+	if (select) {
+		writel(S3C2410_ADCTSC_PULL_UP_DISABLE | AUTOPST,
+		       ts.io + S3C2410_ADCTSC);
+	} else {
+		mod_timer(&touch_timer, jiffies+1);
+		writel(WAIT4INT | INT_UP, ts.io + S3C2410_ADCTSC);
+	}
+}
+
+/**
+ * s3c2410ts_probe - device core probe entry point
+ * @pdev: The device we are being bound to.
+ *
+ * Initialise, find and allocate any resources we need to run and then
+ * register with the ADC and input systems.
+ */
+static int __init s3c2410ts_probe(struct platform_device *pdev)
+{
+	struct s3c2410_ts_mach_info *info;
+	struct device *dev = &pdev->dev;
+	struct input_dev *input_dev;
+	struct resource *res;
+	int ret = -EINVAL;
+
+	/* Initialise input stuff */
+	memset(&ts, 0, sizeof(struct s3c2410ts));
+
+	ts.dev = dev;
+
+	info = pdev->dev.platform_data;
+	if (!info) {
+		dev_err(dev, "no platform data, cannot attach\n");
+		return -EINVAL;
+	}
+
+	dev_dbg(dev, "initialising touchscreen\n");
+
+	ts.clock = clk_get(dev, "adc");
+	if (IS_ERR(ts.clock)) {
+		dev_err(dev, "cannot get adc clock source\n");
+		return -ENOENT;
+	}
+
+	clk_enable(ts.clock);
+	dev_dbg(dev, "got and enabled clocks\n");
+
+	ts.irq_tc = ret = platform_get_irq(pdev, 0);
+	if (ret < 0) {
+		dev_err(dev, "no resource for interrupt\n");
+		goto err_clk;
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(dev, "no resource for registers\n");
+		ret = -ENOENT;
+		goto err_clk;
+	}
+
+	ts.io = ioremap(res->start, resource_size(res));
+	if (ts.io == NULL) {
+		dev_err(dev, "cannot map registers\n");
+		ret = -ENOMEM;
+		goto err_clk;
+	}
+
+	/* Configure the touchscreen external FETs on the S3C2410 */
+	if (!platform_get_device_id(pdev)->driver_data)
+		s3c2410_ts_connect();
+
+	ts.client = s3c_adc_register(pdev, s3c24xx_ts_select,
+				     s3c24xx_ts_conversion, 1);
+	if (IS_ERR(ts.client)) {
+		dev_err(dev, "failed to register adc client\n");
+		ret = PTR_ERR(ts.client);
+		goto err_iomap;
+	}
+
+	/* Initialise registers */
+	if ((info->delay & 0xffff) > 0)
+		writel(info->delay & 0xffff, ts.io + S3C2410_ADCDLY);
+
+	writel(WAIT4INT | INT_DOWN, ts.io + S3C2410_ADCTSC);
+
+	input_dev = input_allocate_device();
+	if (!input_dev) {
+		dev_err(dev, "Unable to allocate the input device !!\n");
+		ret = -ENOMEM;
+		goto err_iomap;
+	}
+
+	ts.input = input_dev;
+	ts.input->evbit[0] = BIT_MASK(EV_SYN) | BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
+	ts.input->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
+	input_set_abs_params(ts.input, ABS_X, 0, 0x3FF, 0, 0);
+	input_set_abs_params(ts.input, ABS_Y, 0, 0x3FF, 0, 0);
+	input_set_abs_params(ts.input, ABS_PRESSURE, 0, 1, 0, 0);
+
+	ts.input->name = s3c2410ts_name;
+	ts.input->id.bustype = BUS_HOST;
+	ts.input->id.vendor = 0xDEAD;
+	ts.input->id.product = 0xBEEF;
+	ts.input->id.version = S3C2410TSVERSION;
+
+	ts.shift = info->oversampling_shift;
+
+	if (request_irq(ts.irq_tc, stylus_irq, IRQF_DISABLED,
+			"s3c2410_ts_pen", ts.input)) {
+		dev_err(dev, "cannot get TC interrupt\n");
+		ret = -EIO;
+		goto err_inputdev;
+	}
+
+	dev_info(dev, "driver attached, registering input device\n");
+
+	/* All went ok, so register to the input system */
+	ret = input_register_device(ts.input);
+	if (ret < 0) {
+		dev_err(dev, "failed to register input device\n");
+		ret = -EIO;
+		goto err_tcirq;
+	}
+
+	return 0;
+
+ err_tcirq:
+	free_irq(ts.irq_tc, ts.input);
+ err_inputdev:
+	input_unregister_device(ts.input);
+ err_iomap:
+	iounmap(ts.io);
+ err_clk:
+	clk_put(ts.clock);
+	return ret;
+}
+
+/**
+ * s3c2410ts_remove - device core removal entry point
+ * @pdev: The device we are being removed from.
+ *
+ * Free up our state ready to be removed.
+ */
+static int s3c2410ts_remove(struct platform_device *pdev)
+{
+	free_irq(ts.irq_tc, ts.input);
+
+	clk_disable(ts.clock);
+	clk_put(ts.clock);
+
+	input_unregister_device(ts.input);
+	iounmap(ts.io);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int s3c2410ts_suspend(struct platform_device *pdev, pm_message_t state)
+{
+	writel(TSC_SLEEP, ts.io + S3C2410_ADCTSC);
+	disable_irq(ts.irq_tc);
+	clk_disable(ts.clock);
+
+	return 0;
+}
+
+static int s3c2410ts_resume(struct platform_device *pdev)
+{
+	struct s3c2410_ts_mach_info *info = pdev->dev.platform_data;
+
+	clk_enable(ts.clock);
+
+	/* Initialise registers */
+	if ((info->delay & 0xffff) > 0)
+		writel(info->delay & 0xffff, ts.io + S3C2410_ADCDLY);
+
+	writel(WAIT4INT | INT_DOWN, ts.io + S3C2410_ADCTSC);
+
+	return 0;
+}
+
+#else
+#define s3c2410ts_suspend NULL
+#define s3c2410ts_resume  NULL
+#endif
+
+static struct platform_device_id s3cts_driver_ids[] = {
+	{ "s3c2410-ts", 0 },
+	{ "s3c2440-ts", 1 },
+	{ }
+};
+MODULE_DEVICE_TABLE(platform, s3cts_driver_ids);
+
+static struct platform_driver s3c_ts_driver = {
+	.driver         = {
+		.name   = "s3c24xx-ts",
+		.owner  = THIS_MODULE,
+	},
+	.id_table	= s3cts_driver_ids,
+	.probe		= s3c2410ts_probe,
+	.remove		= s3c2410ts_remove,
+	.suspend	= s3c2410ts_suspend,
+	.resume		= s3c2410ts_resume,
+};
+
+static int __init s3c2410ts_init(void)
+{
+	return platform_driver_register(&s3c_ts_driver);
+}
+
+static void __exit s3c2410ts_exit(void)
+{
+	platform_driver_unregister(&s3c_ts_driver);
+}
+
+module_init(s3c2410ts_init);
+module_exit(s3c2410ts_exit);
+
+MODULE_AUTHOR("Arnaud Patard <arnaud.patard@rtp-net.org>, "
+	      "Ben Dooks <ben@simtec.co.uk>, "
+	      "Simtec Electronics <linux@simtec.co.uk>");
+MODULE_DESCRIPTION("S3C24XX Touchscreen driver");
+MODULE_LICENSE("GPL v2");