Input: add support for Wacom Stylus device with I2C interface
authorTatsunosuke Tobita <tobita.tatsunosuke@wacom.co.jp>
Mon, 26 Mar 2012 00:23:19 +0000 (17:23 -0700)
committerDmitry Torokhov <dmitry.torokhov@gmail.com>
Wed, 4 Apr 2012 16:24:23 +0000 (09:24 -0700)
This adds support for Wacom Stylus device with I2C interface.

[Dan Carpenter <dan.carpenter@oracle.com>: fix NULL-pointer dereference
 in error handling path.]
Signed-off-by: Tatsunosuke Tobita <tobita.tatsunosuke@wacom.co.jp>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
drivers/input/touchscreen/Kconfig
drivers/input/touchscreen/Makefile
drivers/input/touchscreen/wacom_i2c.c [new file with mode: 0644]

index 97b31a0..c5eb2b9 100644 (file)
@@ -306,6 +306,18 @@ config TOUCHSCREEN_WACOM_W8001
          To compile this driver as a module, choose M here: the
          module will be called wacom_w8001.
 
+config TOUCHSCREEN_WACOM_I2C
+       tristate "Wacom Tablet support (I2C)"
+       depends on I2C
+       help
+         Say Y here if you want to use the I2C version of the Wacom
+         Pen Tablet.
+
+         If unsure, say N.
+
+         To compile this driver as a module, choose M here: the module
+         will be called wacom_i2c.
+
 config TOUCHSCREEN_LPC32XX
        tristate "LPC32XX touchscreen controller"
        depends on ARCH_LPC32XX
index 3d5cf8c..7cca7dd 100644 (file)
@@ -59,6 +59,7 @@ obj-$(CONFIG_TOUCHSCREEN_TSC2005)     += tsc2005.o
 obj-$(CONFIG_TOUCHSCREEN_TSC2007)      += tsc2007.o
 obj-$(CONFIG_TOUCHSCREEN_UCB1400)      += ucb1400_ts.o
 obj-$(CONFIG_TOUCHSCREEN_WACOM_W8001)  += wacom_w8001.o
+obj-$(CONFIG_TOUCHSCREEN_WACOM_I2C)    += wacom_i2c.o
 obj-$(CONFIG_TOUCHSCREEN_WM831X)       += wm831x-ts.o
 obj-$(CONFIG_TOUCHSCREEN_WM97XX)       += wm97xx-ts.o
 wm97xx-ts-$(CONFIG_TOUCHSCREEN_WM9705) += wm9705.o
diff --git a/drivers/input/touchscreen/wacom_i2c.c b/drivers/input/touchscreen/wacom_i2c.c
new file mode 100644 (file)
index 0000000..b8ca4a6
--- /dev/null
@@ -0,0 +1,315 @@
+/*
+ * Wacom Penabled Driver for I2C
+ *
+ * Copyright (c) 2011 Tatsunosuke Tobita, Wacom.
+ * <tobita.tatsunosuke@wacom.co.jp>
+ *
+ * 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 of 2 of the License,
+ * or (at your option) any later version.
+ */
+
+#include <linux/module.h>
+#include <linux/input.h>
+#include <linux/i2c.h>
+#include <linux/slab.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+#include <linux/gpio.h>
+#include <asm/unaligned.h>
+
+#define WACOM_CMD_QUERY0       0x04
+#define WACOM_CMD_QUERY1       0x00
+#define WACOM_CMD_QUERY2       0x33
+#define WACOM_CMD_QUERY3       0x02
+#define WACOM_CMD_THROW0       0x05
+#define WACOM_CMD_THROW1       0x00
+#define WACOM_QUERY_SIZE       19
+#define WACOM_RETRY_CNT                100
+
+struct wacom_features {
+       int x_max;
+       int y_max;
+       int pressure_max;
+       char fw_version;
+};
+
+struct wacom_i2c {
+       struct i2c_client *client;
+       struct input_dev *input;
+       unsigned int gpio;
+       u8 data[WACOM_QUERY_SIZE];
+};
+
+static int wacom_query_device(struct i2c_client *client,
+                             struct wacom_features *features)
+{
+       int ret;
+       u8 cmd1[] = { WACOM_CMD_QUERY0, WACOM_CMD_QUERY1,
+                       WACOM_CMD_QUERY2, WACOM_CMD_QUERY3 };
+       u8 cmd2[] = { WACOM_CMD_THROW0, WACOM_CMD_THROW1 };
+       u8 data[WACOM_QUERY_SIZE];
+       struct i2c_msg msgs[] = {
+               {
+                       .addr = client->addr,
+                       .flags = 0,
+                       .len = sizeof(cmd1),
+                       .buf = cmd1,
+               },
+               {
+                       .addr = client->addr,
+                       .flags = 0,
+                       .len = sizeof(cmd2),
+                       .buf = cmd2,
+               },
+               {
+                       .addr = client->addr,
+                       .flags = I2C_M_RD,
+                       .len = sizeof(data),
+                       .buf = data,
+               },
+       };
+
+       ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
+       if (ret < 0)
+               return ret;
+       if (ret != ARRAY_SIZE(msgs))
+               return -EIO;
+
+       features->x_max = get_unaligned_le16(&data[3]);
+       features->y_max = get_unaligned_le16(&data[5]);
+       features->pressure_max = get_unaligned_le16(&data[11]);
+       features->fw_version = get_unaligned_le16(&data[13]);
+
+       dev_dbg(&client->dev,
+               "x_max:%d, y_max:%d, pressure:%d, fw:%d\n",
+               features->x_max, features->y_max,
+               features->pressure_max, features->fw_version);
+
+       return 0;
+}
+
+static int wacom_i2c_fetch_data(struct wacom_i2c *wac_i2c)
+{
+       int retries = 0;
+       int ret;
+
+       do {
+               ret = i2c_master_recv(wac_i2c->client,
+                                     wac_i2c->data, sizeof(wac_i2c->data));
+       } while (gpio_get_value(wac_i2c->gpio) == 0 &&
+                retries++ < WACOM_RETRY_CNT);
+
+       if (retries >= WACOM_RETRY_CNT)
+               ret = -EIO;
+
+       return ret < 0 ? ret : 0;
+}
+
+static irqreturn_t wacom_i2c_irq(int irq, void *dev_id)
+{
+       struct wacom_i2c *wac_i2c = dev_id;
+       struct input_dev *input = wac_i2c->input;
+       u8 *data = wac_i2c->data;
+       unsigned int x, y, pressure;
+       unsigned char tsw, f1, f2, ers;
+       int error;
+
+       error = wacom_i2c_fetch_data(wac_i2c);
+       if (error)
+               goto out;
+
+       tsw = data[3] & 0x01;
+       ers = data[3] & 0x04;
+       f1 = data[3] & 0x02;
+       f2 = data[3] & 0x10;
+       x = le16_to_cpup((__le16 *)&data[4]);
+       y = le16_to_cpup((__le16 *)&data[6]);
+       pressure = le16_to_cpup((__le16 *)&data[8]);
+
+       input_report_key(input, BTN_TOUCH, tsw || ers);
+       input_report_key(input, BTN_TOOL_PEN, tsw);
+       input_report_key(input, BTN_TOOL_RUBBER, ers);
+       input_report_key(input, BTN_STYLUS, f1);
+       input_report_key(input, BTN_STYLUS2, f2);
+       input_report_abs(input, ABS_X, x);
+       input_report_abs(input, ABS_Y, y);
+       input_report_abs(input, ABS_PRESSURE, pressure);
+       input_sync(input);
+
+out:
+       return IRQ_HANDLED;
+}
+
+static int wacom_i2c_open(struct input_dev *dev)
+{
+       struct wacom_i2c *wac_i2c = input_get_drvdata(dev);
+       struct i2c_client *client = wac_i2c->client;
+       int error;
+
+       /* Clear the device buffer */
+       error = wacom_i2c_fetch_data(wac_i2c);
+       if (error)
+               return error;
+
+       enable_irq(client->irq);
+
+       return 0;
+}
+
+static void wacom_i2c_close(struct input_dev *dev)
+{
+       struct wacom_i2c *wac_i2c = input_get_drvdata(dev);
+       struct i2c_client *client = wac_i2c->client;
+
+       disable_irq(client->irq);
+}
+
+static int __devinit wacom_i2c_probe(struct i2c_client *client,
+                                    const struct i2c_device_id *id)
+{
+       struct wacom_i2c *wac_i2c;
+       struct input_dev *input;
+       struct wacom_features features;
+       int gpio;
+       int error;
+
+       if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
+               dev_err(&client->dev, "i2c_check_functionality error\n");
+               return -EIO;
+       }
+
+       gpio = irq_to_gpio(client->irq);
+       if (gpio < 0) {
+               error = gpio;
+               dev_err(&client->dev,
+                       "irq_to_gpio() failed, error: %d\n", error);
+               return error;
+       }
+
+       error = wacom_query_device(client, &features);
+       if (error)
+               return error;
+
+       wac_i2c = kzalloc(sizeof(*wac_i2c), GFP_KERNEL);
+       input = input_allocate_device();
+       if (!wac_i2c || !input) {
+               error = -ENOMEM;
+               goto err_free_mem;
+       }
+
+       wac_i2c->client = client;
+       wac_i2c->input = input;
+       wac_i2c->gpio = gpio;
+
+       input->name = "Wacom I2C Digitizer";
+       input->id.bustype = BUS_I2C;
+       input->id.vendor = 0x56a;
+       input->id.version = features.fw_version;
+       input->dev.parent = &client->dev;
+       input->open = wacom_i2c_open;
+       input->close = wacom_i2c_close;
+
+       input->evbit[0] |= BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
+
+       __set_bit(BTN_TOOL_PEN, input->keybit);
+       __set_bit(BTN_TOOL_RUBBER, input->keybit);
+       __set_bit(BTN_STYLUS, input->keybit);
+       __set_bit(BTN_STYLUS2, input->keybit);
+       __set_bit(BTN_TOUCH, input->keybit);
+
+       input_set_abs_params(input, ABS_X, 0, features.x_max, 0, 0);
+       input_set_abs_params(input, ABS_Y, 0, features.y_max, 0, 0);
+       input_set_abs_params(input, ABS_PRESSURE,
+                            0, features.pressure_max, 0, 0);
+
+       input_set_drvdata(input, wac_i2c);
+
+       error = request_threaded_irq(client->irq, NULL, wacom_i2c_irq,
+                                    IRQF_TRIGGER_FALLING,
+                                    "wacom_i2c", wac_i2c);
+       if (error) {
+               dev_err(&client->dev,
+                       "Failed to enable IRQ, error: %d\n", error);
+               goto err_free_mem;
+       }
+
+       /* Disable the IRQ, we'll enable it in wac_i2c_open() */
+       disable_irq(client->irq);
+
+       error = input_register_device(wac_i2c->input);
+       if (error) {
+               dev_err(&client->dev,
+                       "Failed to register input device, error: %d\n", error);
+               goto err_free_irq;
+       }
+
+       i2c_set_clientdata(client, wac_i2c);
+       return 0;
+
+err_free_irq:
+       free_irq(client->irq, wac_i2c);
+err_free_mem:
+       input_free_device(input);
+       kfree(wac_i2c);
+
+       return error;
+}
+
+static int __devexit wacom_i2c_remove(struct i2c_client *client)
+{
+       struct wacom_i2c *wac_i2c = i2c_get_clientdata(client);
+
+       free_irq(client->irq, wac_i2c);
+       input_unregister_device(wac_i2c->input);
+       kfree(wac_i2c);
+
+       return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int wacom_i2c_suspend(struct device *dev)
+{
+       struct i2c_client *client = to_i2c_client(dev);
+
+       disable_irq(client->irq);
+
+       return 0;
+}
+
+static int wacom_i2c_resume(struct device *dev)
+{
+       struct i2c_client *client = to_i2c_client(dev);
+
+       enable_irq(client->irq);
+
+       return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(wacom_i2c_pm, wacom_i2c_suspend, wacom_i2c_resume);
+
+static const struct i2c_device_id wacom_i2c_id[] = {
+       { "WAC_I2C_EMR", 0 },
+       { },
+};
+MODULE_DEVICE_TABLE(i2c, wacom_i2c_id);
+
+static struct i2c_driver wacom_i2c_driver = {
+       .driver = {
+               .name   = "wacom_i2c",
+               .owner  = THIS_MODULE,
+               .pm     = &wacom_i2c_pm,
+       },
+
+       .probe          = wacom_i2c_probe,
+       .remove         = __devexit_p(wacom_i2c_remove),
+       .id_table       = wacom_i2c_id,
+};
+module_i2c_driver(wacom_i2c_driver);
+
+MODULE_AUTHOR("Tatsunosuke Tobita <tobita.tatsunosuke@wacom.co.jp>");
+MODULE_DESCRIPTION("WACOM EMR I2C Driver");
+MODULE_LICENSE("GPL");