Input: add Austria Microsystem AS5011 joystick driver

This is driver for EasyPoint AS5011 2 axis joystick chip. This chip is
plugged on an I2C bus.

Tested on ARM processor (i.MX27).

Signed-off-by: Fabien Marteau <fabien.marteau@armadeus.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

4 files changed, 398 insertions, 0 deletions

diff --git a/drivers/input/joystick/Kconfig b/drivers/input/joystick/Kconfig
index 5b596165b571..56eb471b5576 100644
--- a/drivers/input/joystick/Kconfig
+++ b/drivers/input/joystick/Kconfig
@@ -255,6 +255,16 @@ config JOYSTICK_AMIGA
           To compile this driver as a module, choose M here: the
           module will be called amijoy.
 
+config JOYSTICK_AS5011
+        tristate "Austria Microsystem AS5011 joystick"
+        depends on I2C
+        help
+          Say Y here if you have an AS5011 digital joystick connected to your
+          system.
+
+          To compile this driver as a module, choose M here: the
+          module will be called as5011.
+
 config JOYSTICK_JOYDUMP
         tristate "Gameport data dumper"
         select GAMEPORT
diff --git a/drivers/input/joystick/Makefile b/drivers/input/joystick/Makefile
index f3a8cbe2abb6..92dc0de9dfed 100644
--- a/drivers/input/joystick/Makefile
+++ b/drivers/input/joystick/Makefile
@@ -7,6 +7,7 @@
 obj-$(CONFIG_JOYSTICK_A3D)              += a3d.o
 obj-$(CONFIG_JOYSTICK_ADI)              += adi.o
 obj-$(CONFIG_JOYSTICK_AMIGA)            += amijoy.o
+obj-$(CONFIG_JOYSTICK_AS5011)           += as5011.o
 obj-$(CONFIG_JOYSTICK_ANALOG)           += analog.o
 obj-$(CONFIG_JOYSTICK_COBRA)            += cobra.o
 obj-$(CONFIG_JOYSTICK_DB9)              += db9.o
diff --git a/drivers/input/joystick/as5011.c b/drivers/input/joystick/as5011.c
new file mode 100644
index 000000000000..f6732b57ca07
--- /dev/null
+++ b/drivers/input/joystick/as5011.c
@@ -0,0 +1,367 @@
+/*
+ * Copyright (c) 2010, 2011 Fabien Marteau <fabien.marteau@armadeus.com>
+ * Sponsored by ARMadeus Systems
+ *
+ * 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; 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
+ *
+ * Driver for Austria Microsystems joysticks AS5011
+ *
+ * TODO:
+ *      - Power on the chip when open() and power down when close()
+ *      - Manage power mode
+ */
+
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/input.h>
+#include <linux/gpio.h>
+#include <linux/delay.h>
+#include <linux/input/as5011.h>
+#include <linux/slab.h>
+
+#define DRIVER_DESC "Driver for Austria Microsystems AS5011 joystick"
+#define MODULE_DEVICE_ALIAS "as5011"
+
+MODULE_AUTHOR("Fabien Marteau <fabien.marteau@armadeus.com>");
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_LICENSE("GPL");
+
+/* registers */
+#define AS5011_CTRL1            0x76
+#define AS5011_CTRL2            0x75
+#define AS5011_XP               0x43
+#define AS5011_XN               0x44
+#define AS5011_YP               0x53
+#define AS5011_YN               0x54
+#define AS5011_X_REG            0x41
+#define AS5011_Y_REG            0x42
+#define AS5011_X_RES_INT        0x51
+#define AS5011_Y_RES_INT        0x52
+
+/* CTRL1 bits */
+#define AS5011_CTRL1_LP_PULSED          0x80
+#define AS5011_CTRL1_LP_ACTIVE          0x40
+#define AS5011_CTRL1_LP_CONTINUE        0x20
+#define AS5011_CTRL1_INT_WUP_EN         0x10
+#define AS5011_CTRL1_INT_ACT_EN         0x08
+#define AS5011_CTRL1_EXT_CLK_EN         0x04
+#define AS5011_CTRL1_SOFT_RST           0x02
+#define AS5011_CTRL1_DATA_VALID         0x01
+
+/* CTRL2 bits */
+#define AS5011_CTRL2_EXT_SAMPLE_EN      0x08
+#define AS5011_CTRL2_RC_BIAS_ON         0x04
+#define AS5011_CTRL2_INV_SPINNING       0x02
+
+#define AS5011_MAX_AXIS 80
+#define AS5011_MIN_AXIS (-80)
+#define AS5011_FUZZ     8
+#define AS5011_FLAT     40
+
+struct as5011_device {
+        struct input_dev *input_dev;
+        struct i2c_client *i2c_client;
+        unsigned int button_gpio;
+        unsigned int button_irq;
+        unsigned int axis_irq;
+};
+
+static int as5011_i2c_write(struct i2c_client *client,
+                            uint8_t aregaddr,
+                            uint8_t avalue)
+{
+        uint8_t data[2] = { aregaddr, avalue };
+        struct i2c_msg msg = {
+                client->addr, I2C_M_IGNORE_NAK, 2, (uint8_t *)data
+        };
+        int error;
+
+        error = i2c_transfer(client->adapter, &msg, 1);
+        return error < 0 ? error : 0;
+}
+
+static int as5011_i2c_read(struct i2c_client *client,
+                           uint8_t aregaddr, signed char *value)
+{
+        uint8_t data[2] = { aregaddr };
+        struct i2c_msg msg_set[2] = {
+                { client->addr, I2C_M_REV_DIR_ADDR, 1, (uint8_t *)data },
+                { client->addr, I2C_M_RD | I2C_M_NOSTART, 1, (uint8_t *)data }
+        };
+        int error;
+
+        error = i2c_transfer(client->adapter, msg_set, 2);
+        if (error < 0)
+                return error;
+
+        *value = data[0] & 0x80 ? -1 * (1 + ~data[0]) : data[0];
+        return 0;
+}
+
+static irqreturn_t as5011_button_interrupt(int irq, void *dev_id)
+{
+        struct as5011_device *as5011 = dev_id;
+        int val = gpio_get_value_cansleep(as5011->button_gpio);
+
+        input_report_key(as5011->input_dev, BTN_JOYSTICK, !val);
+        input_sync(as5011->input_dev);
+
+        return IRQ_HANDLED;
+}
+
+static irqreturn_t as5011_axis_interrupt(int irq, void *dev_id)
+{
+        struct as5011_device *as5011 = dev_id;
+        int error;
+        signed char x, y;
+
+        error = as5011_i2c_read(as5011->i2c_client, AS5011_X_RES_INT, &x);
+        if (error < 0)
+                goto out;
+
+        error = as5011_i2c_read(as5011->i2c_client, AS5011_Y_RES_INT, &y);
+        if (error < 0)
+                goto out;
+
+        input_report_abs(as5011->input_dev, ABS_X, x);
+        input_report_abs(as5011->input_dev, ABS_Y, y);
+        input_sync(as5011->input_dev);
+
+out:
+        return IRQ_HANDLED;
+}
+
+static int __devinit as5011_configure_chip(struct as5011_device *as5011,
+                                const struct as5011_platform_data *plat_dat)
+{
+        struct i2c_client *client = as5011->i2c_client;
+        int error;
+        signed char value;
+
+        /* chip soft reset */
+        error = as5011_i2c_write(client, AS5011_CTRL1,
+                                 AS5011_CTRL1_SOFT_RST);