Input: add support for Wacom W8001 penabled serial touchscreen

The Wacom W8001 sensor is a sensor device (uses electromagnetic
resonance) and it is interfaced via its serial microcontroller
to the host.

Signed-off-by: Jaya Kumar <jayakumar.lkml@gmail.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

4 files changed, 340 insertions, 0 deletions

diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index 3d1ab8fa9acc..20eb52ed176d 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -95,6 +95,19 @@ config TOUCHSCREEN_ELO
           To compile this driver as a module, choose M here: the
           module will be called elo.
 
+config TOUCHSCREEN_WACOM_W8001
+        tristate "Wacom W8001 penabled serial touchscreen"
+        select SERIO
+        help
+          Say Y here if you have an Wacom W8001 penabled serial touchscreen
+          connected to your system.
+
+          If unsure, say N.
+
+          To compile this driver as a module, choose M here: the
+          module will be called wacom_w8001.
+
+
 config TOUCHSCREEN_MTOUCH
         tristate "MicroTouch serial touchscreens"
         select SERIO
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index 15cf29079489..3dc84d3846c1 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -26,6 +26,7 @@ obj-$(CONFIG_TOUCHSCREEN_TOUCHIT213)	+= touchit213.o
 obj-$(CONFIG_TOUCHSCREEN_TOUCHRIGHT)    += touchright.o
 obj-$(CONFIG_TOUCHSCREEN_TOUCHWIN)      += touchwin.o
 obj-$(CONFIG_TOUCHSCREEN_UCB1400)       += ucb1400_ts.o
+obj-$(CONFIG_TOUCHSCREEN_WACOM_W8001)   += wacom_w8001.o
 obj-$(CONFIG_TOUCHSCREEN_WM97XX)        += wm97xx-ts.o
 wm97xx-ts-$(CONFIG_TOUCHSCREEN_WM9705)  += wm9705.o
 wm97xx-ts-$(CONFIG_TOUCHSCREEN_WM9712)  += wm9712.o
diff --git a/drivers/input/touchscreen/wacom_w8001.c b/drivers/input/touchscreen/wacom_w8001.c
new file mode 100644
index 000000000000..2f33a0167644
--- /dev/null
+++ b/drivers/input/touchscreen/wacom_w8001.c
@@ -0,0 +1,325 @@
+/*
+ * Wacom W8001 penabled serial touchscreen driver
+ *
+ * Copyright (c) 2008 Jaya Kumar
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file COPYING in the main directory of this archive for
+ * more details.
+ *
+ * Layout based on Elo serial touchscreen driver by Vojtech Pavlik
+ */
+
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/input.h>
+#include <linux/serio.h>
+#include <linux/init.h>
+#include <linux/ctype.h>
+
+#define DRIVER_DESC     "Wacom W8001 serial touchscreen driver"
+
+MODULE_AUTHOR("Jaya Kumar <jayakumar.lkml@gmail.com>");
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_LICENSE("GPL");
+
+/*
+ * Definitions & global arrays.
+ */
+
+#define W8001_MAX_LENGTH        11
+#define W8001_PACKET_LEN        11
+#define W8001_LEAD_MASK 0x80
+#define W8001_LEAD_BYTE 0x80
+#define W8001_TAB_MASK 0x40
+#define W8001_TAB_BYTE 0x40
+
+#define W8001_QUERY_PACKET 0x20
+
+struct w8001_coord {
+        u8 rdy;
+        u8 tsw;
+        u8 f1;
+        u8 f2;
+        u16 x;
+        u16 y;
+        u16 pen_pressure;
+        u8 tilt_x;
+        u8 tilt_y;
+};
+
+/*
+ * Per-touchscreen data.
+ */
+
+struct w8001 {
+        struct input_dev *dev;
+        struct serio *serio;
+        struct mutex cmd_mutex;
+        struct completion cmd_done;
+        int id;
+        int idx;
+        unsigned char expected_packet;
+        unsigned char data[W8001_MAX_LENGTH];
+        unsigned char response[W8001_PACKET_LEN];
+        char phys[32];
+};
+
+static int parse_data(u8 *data, struct w8001_coord *coord)
+{
+        coord->rdy = data[0] & 0x20;
+        coord->tsw = data[0] & 0x01;
+        coord->f1 = data[0] & 0x02;
+        coord->f2 = data[0] & 0x04;
+
+        coord->x = (data[1] & 0x7F) << 9;
+        coord->x |= (data[2] & 0x7F) << 2;
+        coord->x |= (data[6] & 0x60) >> 5;
+
+        coord->y = (data[3] & 0x7F) << 9;
+        coord->y |= (data[4] & 0x7F) << 2;
+        coord->y |= (data[6] & 0x18) >> 3;
+
+        coord->pen_pressure = data[5] & 0x7F;
+        coord->pen_pressure |= (data[6] & 0x07) << 7 ;
+
+        coord->tilt_x = data[7] & 0x7F;
+        coord->tilt_y = data[8] & 0x7F;
+
+        return 0;
+}
+
+static void w8001_process_data(struct w8001 *w8001, unsigned char data)
+{
+        struct input_dev *dev = w8001->dev;
+        u8 tmp;
+        struct w8001_coord coord;
+
+        w8001->data[w8001->idx] = data;
+        switch (w8001->idx++) {
+        case 0:
+                if ((data & W8001_LEAD_MASK) != W8001_LEAD_BYTE) {
+                        pr_debug("w8001: unsynchronized data: 0x%02x\n", data);
+                        w8001->idx = 0;
+                }
+                break;
+        case 8:
+                tmp = w8001->data[0] & W8001_TAB_MASK;
+                if (unlikely(tmp == W8001_TAB_BYTE))
+                        break;
+                w8001->idx = 0;
+                memset(&coord, 0, sizeof(coord));
+                parse_data(w8001->data, &coord);
+                input_report_abs(dev, ABS_X, coord.x);
+                input_report_abs(dev, ABS_Y, coord.y);
+                input_report_abs(dev, ABS_PRESSURE, coord.pen_pressure);
+                input_report_key(dev, BTN_TOUCH, coord.tsw);
+                input_sync(dev);
+                break;
+        case 10:
+                w8001->idx = 0;
+                memcpy(w8001->response, &w8001->data, W8001_PACKET_LEN);
+                w8001->expected_packet = W8001_QUERY_PACKET;
+                complete(&w8001->cmd_done);
+                break;
+        }
+}
+
+
+static irqreturn_t w8001_interrupt(struct serio *serio,
+                unsigned char data, unsigned int flags)
+{
+        struct w8001 *w8001 = serio_get_drvdata(serio);
+
+        w8001_process_data(w8001, data);
+
+        return IRQ_HANDLED;
+}
+
+static int w8001_async_command(struct w8001 *w8001, unsigned char *packet,
+                                        int len)
+{
+        int rc = -1;
+        int i;
+
+        mutex_lock(&w8001->cmd_mutex);
+
+