Re: [PATCH] Add support for HTC Shift Touchscreen

[Pau Oliva Fora <pau@eslack.org>]

From: Pau Oliva Fora <pau@eslack.org>

The patch below adds support for HTC Shift UMPC touchscreen.

Signed-off-by: Pau Oliva Fora <pau@eslack.org>

---

Patch against linux-2.6.25.4, should apply clean on other versions too.
Thanks to Sam Ravnborg and Pekka Enberg for their comments, my reply below:

Sam Ravnborg wrote:
 > The use of the four ports would be nice to be documented

done, changed the DEFINE names


 >> +		outb_p(3, HTCPEN_PORT2);
 > What is the semantic of 3 here.
 > Add a comment or a DEFINE

added DEFINES for those


 > These calculations needs spaces and comments.

Done, hope is ok now.


 > I would asusme you are missing a: input_unregister_device(htcpen_dev);?

no, device is not yet registered here.


Pekka Enberg wrote:
 >> +struct input_dev *htcpen_dev;
 >
 > Why are you not using isa_register_driver() instead?

I have no specifications from the manufacturer, so don't know how to
properly prove the device, etc.


 >> +       printk(KERN_INFO "htcpen: module inserted\n");
 >> +
 >> +       inb_p(HTCPEN_PORT0);
 >
 > So there's no way to probe the existence of this device?

I can add a minimal sanity check if that is a must, but I don't have
a datasheet and contacting HTC did not help.


 >> +       if (request_irq(HTCPEN_IRQ, htcpen_interrupt, 0, "htcpen", NULL)) {
 >
 > This is leaking htcpen_dev here. Look at some other drivers for
 > examples how to use gotos for this kind of error handling.

Thanks, should be fixed now.


diff -uprN linux-2.6.25.4/drivers/input/touchscreen/htcpen.c linux/drivers/input/touchscreen/htcpen.c
--- linux-2.6.25.4/drivers/input/touchscreen/htcpen.c	1970-01-01 01:00:00.000000000 +0100
+++ linux/drivers/input/touchscreen/htcpen.c	2008-05-17 17:38:35.000000000 +0200
@@ -0,0 +1,155 @@
+/*
+ * HTC Shift touchscreen driver
+ *
+ * Copyright (C) 2008 Pau Oliva Fora <pof@eslack.org>
+ *
+ * Thanks to:
+ * 	Heikki Linnakangas - Penmount LPC touchscreen driver
+ * 	Wacom / Ping Cheng - Help on linuxwacom-devel
+ * 	Esteve Espuna      - Ideas, tips, moral support :)
+ *
+ * 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/errno.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/init.h>
+#include <linux/irq.h>
+
+#define DRIVER_VERSION		"v0.5"
+#define DRIVER_DESC	"HTC Shift touchscreen driver"
+
+MODULE_AUTHOR("Pau Oliva Fora <pau@eslack.org>");
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_LICENSE("GPL");
+
+#define HTCPEN_PORT_IRQ_CLEAR 0x068
+#define HTCPEN_PORT_INIT 0x06c
+#define HTCPEN_PORT_INDEX 0x0250
+#define HTCPEN_PORT_DATA 0x0251
+#define HTCPEN_IRQ 3
+
+#define X_INDEX 3
+#define Y_INDEX 5
+#define LSB_XY_INDEX 0xc
+#define X_AXIS_MAX 2040
+#define Y_AXIS_MAX 2040
+#define DEVICE_ENABLE 0xa2
+
+static int inverse_y;
+module_param(inverse_y, bool, 0644);
+MODULE_PARM_DESC(inverse_y, "If set Y axis is inversed.");
+
+struct input_dev *htcpen_dev;
+
+static void poll_htcpen(void)
+{
+	unsigned short x, y, xy;
+	unsigned short touch;
+
+	/* 0=press ; 1=release */
+	outb_p(0xb, HTCPEN_PORT_INDEX);
+	touch = inb_p(HTCPEN_PORT_DATA);
+	if (touch)
+		touch = 0;
+	else
+		touch = 1;
+
+	input_report_key(htcpen_dev, BTN_TOUCH, touch);
+
+	/* only update X/Y when screen is being touched */
+	if (touch) {
+		outb_p(X_INDEX, HTCPEN_PORT_INDEX);
+		x = inb_p(HTCPEN_PORT_DATA);
+
+		outb_p(Y_INDEX, HTCPEN_PORT_INDEX);
+		y = inb_p(HTCPEN_PORT_DATA);
+
+		outb_p(LSB_XY_INDEX, HTCPEN_PORT_INDEX);
+		xy = inb_p(HTCPEN_PORT_DATA);
+
+		/* get high resolution value of X and Y using LSB */
+		x = X_AXIS_MAX - ((x * 8) + ((xy >> 4) & 0xf));
+		y = (y * 8) + (xy & 0xf);
+		if (inverse_y)
+			y = Y_AXIS_MAX - y;
+
+		input_report_abs(htcpen_dev, ABS_X, x);
+		input_report_abs(htcpen_dev, ABS_Y, y);
+	}
+
+	input_sync(htcpen_dev);
+
+	inb_p(HTCPEN_PORT_IRQ_CLEAR);
+}
+
+static irqreturn_t htcpen_interrupt(int irq, void *handle)
+{
+	poll_htcpen();
+	return IRQ_HANDLED;
+}
+
+static int __init htcpen_init(void)
+{
+	int err;
+
+	printk(KERN_INFO "htcpen: module inserted\n");
+
+	inb_p(HTCPEN_PORT_IRQ_CLEAR);
+
+	htcpen_dev = input_allocate_device();
+	if (!htcpen_dev) {
+		printk(KERN_ERR "htcpen: can't allocate device\n");
+		err = -ENOMEM;
+		goto fail1;
+	}
+
+	htcpen_dev->name = "HTC Pen TouchScreen";
+	htcpen_dev->id.bustype = BUS_ISA;
+	htcpen_dev->id.vendor = 0;
+	htcpen_dev->id.product = 0;
+	htcpen_dev->id.version = 0;
+
+	input_set_abs_params(htcpen_dev, ABS_X, 0, X_AXIS_MAX, 0, 0);
+	input_set_abs_params(htcpen_dev, ABS_Y, 0, Y_AXIS_MAX, 0, 0);
+
+	htcpen_dev->evbit[0] = BIT_MASK(EV_ABS) | BIT_MASK(EV_KEY);
+	htcpen_dev->absbit[0] = BIT_MASK(ABS_X) | BIT_MASK(ABS_Y);
+	htcpen_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
+
+	err = request_irq(HTCPEN_IRQ, htcpen_interrupt, 0, "htcpen",
+		htcpen_dev);
+	if (err) {
+		printk(KERN_ERR "htcpen: irq busy\n");
+		err = -EBUSY;
+		goto fail1;
+	}
+
+	err = input_register_device(htcpen_dev);
+	if (err)
+		goto fail2;
+
+	outb_p(DEVICE_ENABLE, HTCPEN_PORT_INIT);
+
+	return 0;
+
+ fail2:	free_irq(HTCPEN_IRQ, htcpen_dev);
+ fail1:	input_free_device(htcpen_dev);
+	return err;
+}
+
+static void __exit htcpen_exit(void)
+{
+	input_unregister_device(htcpen_dev);
+	free_irq(HTCPEN_IRQ, htcpen_dev);
+	printk(KERN_INFO "htcpen: module removed\n");
+}
+
+module_init(htcpen_init);
+module_exit(htcpen_exit);
diff -uprN linux-2.6.25.4/drivers/input/touchscreen/Kconfig linux/drivers/input/touchscreen/Kconfig
--- linux-2.6.25.4/drivers/input/touchscreen/Kconfig	2008-05-15 17:00:12.000000000 +0200
+++ linux/drivers/input/touchscreen/Kconfig	2008-05-17 03:23:14.000000000 +0200
@@ -134,6 +134,17 @@ config TOUCHSCREEN_HP7XX
  	  To compile this driver as a module, choose M here: the
  	  module will be called jornada720_ts.

+config TOUCHSCREEN_HTCPEN
+	tristate "HTC Shift X9500 touchscreen"
+	help
+	  Say Y here if you have an HTC Shift UMPC also known as HTC X9500
+	  Clio / Shangrila and want to support the built-in touchscreen.
+
+	  If unsure, say N.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called htcpen.
+
  config TOUCHSCREEN_PENMOUNT
  	tristate "Penmount serial touchscreen"
  	select SERIO
diff -uprN linux-2.6.25.4/drivers/input/touchscreen/Makefile linux/drivers/input/touchscreen/Makefile
--- linux-2.6.25.4/drivers/input/touchscreen/Makefile	2008-05-15 17:00:12.000000000 +0200
+++ linux/drivers/input/touchscreen/Makefile	2008-05-17 03:10:12.000000000 +0200
@@ -14,6 +14,7 @@ obj-$(CONFIG_TOUCHSCREEN_MTOUCH)	+= mtou
  obj-$(CONFIG_TOUCHSCREEN_MK712)		+= mk712.o
  obj-$(CONFIG_TOUCHSCREEN_HP600)		+= hp680_ts_input.o
  obj-$(CONFIG_TOUCHSCREEN_HP7XX)		+= jornada720_ts.o
+obj-$(CONFIG_TOUCHSCREEN_HTCPEN)	+= htcpen.o
  obj-$(CONFIG_TOUCHSCREEN_USB_COMPOSITE)	+= usbtouchscreen.o
  obj-$(CONFIG_TOUCHSCREEN_PENMOUNT)	+= penmount.o
  obj-$(CONFIG_TOUCHSCREEN_TOUCHRIGHT)	+= touchright.o