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authorTatsunosuke Tobita <tobita.tatsunosuke@wacom.co.jp>2012-03-26 04:23:19 +0400
committerDmitry Torokhov <dmitry.torokhov@gmail.com>2012-04-04 20:24:23 +0400
commit5a966261c0dfb836f54444ff3893638802183cac (patch)
tree335a2475bec51b2eea1b3a503d4838c539c2ee97 /drivers/input/touchscreen/wacom_i2c.c
parent271002ca7956e5ef140c02af1bd8e93063924ec6 (diff)
downloadlinux-5a966261c0dfb836f54444ff3893638802183cac.tar.xz
Input: add support for Wacom Stylus device with I2C interface
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>
Diffstat (limited to 'drivers/input/touchscreen/wacom_i2c.c')
-rw-r--r--drivers/input/touchscreen/wacom_i2c.c315
1 files changed, 315 insertions, 0 deletions
diff --git a/drivers/input/touchscreen/wacom_i2c.c b/drivers/input/touchscreen/wacom_i2c.c
new file mode 100644
index 000000000000..b8ca4a6bc91a
--- /dev/null
+++ b/drivers/input/touchscreen/wacom_i2c.c
@@ -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");