This patch implements a simple Keypad driver that functions
as an I2C client. It handles key press events for keys
connected to TCA6416 I2C based IO expander.
Signed-off-by: Sriramakrishnan <srk@xxxxxx>
---
drivers/input/keyboard/Kconfig | 16 ++
drivers/input/keyboard/Makefile | 1 +
drivers/input/keyboard/tca6416-keypad.c | 354 +++++++++++++++++++++++++++++++
include/linux/tca6416_keypad.h | 34 +++
4 files changed, 405 insertions(+), 0 deletions(-)
create mode 100644 drivers/input/keyboard/tca6416-keypad.c
create mode 100644 include/linux/tca6416_keypad.h
diff --git a/drivers/input/keyboard/Kconfig b/drivers/input/keyboard/Kconfig
index 64c1023..cf7fca9 100644
--- a/drivers/input/keyboard/Kconfig
+++ b/drivers/input/keyboard/Kconfig
@@ -192,6 +192,22 @@ config KEYBOARD_GPIO
To compile this driver as a module, choose M here: the
module will be called gpio_keys.
+config KEYBOARD_TCA6416
+ tristate "TCA6416 Keypad Support"
+ depends on I2C
+ help
+ This driver implements basic keypad functionality
+ for keys connected through TCA6416 IO expander
+
+ Say Y here if your device has keys connected to
+ TCA6416 IO expander. Your board-specific setup logic
+ must also provide pin-mask details(of which TCA6416 pins
+ are used for keypad).
+
+ If enabled the complete TCA6416 device will be managed through
+ this driver.
+
+
config KEYBOARD_MATRIX
tristate "GPIO driven matrix keypad support"
depends on GENERIC_GPIO
diff --git a/drivers/input/keyboard/Makefile b/drivers/input/keyboard/Makefile
index 706c6b5..47e267c 100644
--- a/drivers/input/keyboard/Makefile
+++ b/drivers/input/keyboard/Makefile
@@ -15,6 +15,7 @@ obj-$(CONFIG_KEYBOARD_CORGI) += corgikbd.o
obj-$(CONFIG_KEYBOARD_DAVINCI) += davinci_keyscan.o
obj-$(CONFIG_KEYBOARD_EP93XX) += ep93xx_keypad.o
obj-$(CONFIG_KEYBOARD_GPIO) += gpio_keys.o
+obj-$(CONFIG_KEYBOARD_TCA6416) += tca6416-keypad.o
obj-$(CONFIG_KEYBOARD_HIL) += hil_kbd.o
obj-$(CONFIG_KEYBOARD_HIL_OLD) += hilkbd.o
obj-$(CONFIG_KEYBOARD_IMX) += imx_keypad.o
diff --git a/drivers/input/keyboard/tca6416-keypad.c b/drivers/input/keyboard/tca6416-keypad.c
new file mode 100644
index 0000000..17df832
--- /dev/null
+++ b/drivers/input/keyboard/tca6416-keypad.c
@@ -0,0 +1,354 @@
+/*
+ * Driver for keys on TCA6416 I2C IO expander
+ *
+ * Copyright (C) 2010 Texas Instruments
+ *
+ * Author : Sriramakrishnan.A.G. <srk@xxxxxx>
+ *
+ * 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/module.h>
+#include <linux/init.h>
+#include <linux/gpio.h>
+#include <linux/i2c.h>
+#include <linux/input.h>
+#include <linux/tca6416_keypad.h>
+#include <linux/workqueue.h>
+#include <linux/types.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+
+#define TCA6416_INPUT 0
+#define TCA6416_OUTPUT 1
+#define TCA6416_INVERT 2
+#define TCA6416_DIRECTION 3
+
+static const struct i2c_device_id tca6416_id[] = {
+ { "tca6416-keys", 16, },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, tca6416_id);
+
+struct tca6416_drv_data {
+ struct input_dev *input;
+ struct tca6416_button data[0];
+};
+
+struct tca6416_keypad_chip {
+ uint16_t reg_output;
+ uint16_t reg_direction;
+ uint16_t reg_input;
+
+ struct i2c_client *client;
+ struct tca6416_drv_data *drv_data;
+ struct delayed_work dwork;
+ uint16_t pinmask;
+ int irqnum;
+ int use_polling;
+};
+
+static int tca6416_write_reg(struct tca6416_keypad_chip *chip, int reg,
+ uint16_t val)
+{
+ int ret;
+
+ ret = i2c_smbus_write_word_data(chip->client, reg << 1, val);
+
+ if (ret < 0) {
+ dev_err(&chip->client->dev, "failed writing register\n");
+ return ret;
+ }
+
+ return 0;
+}
+
+static int tca6416_read_reg(struct tca6416_keypad_chip *chip, int reg,
+ uint16_t *val)
+{
+ int ret;
+
+ ret = i2c_smbus_read_word_data(chip->client, reg << 1);
+
+ if (ret < 0) {
+ dev_err(&chip->client->dev, "failed reading register\n");
+ return ret;
+ }
+
+ *val = (uint16_t)ret;
+ return 0;
+}
+
+static irqreturn_t tca6416_keys_isr(int irq, void *dev_id)
+{
+ struct tca6416_keypad_chip *chip =
+ (struct tca6416_keypad_chip *) dev_id;
+
+ disable_irq(irq);
+ schedule_delayed_work(&chip->dwork, 0);
+ return IRQ_HANDLED;
+
+}
+
+static void tca6416_keys_work_func(struct work_struct *workstruct)
+{
+ struct delayed_work *delay_work =
+ container_of(workstruct, struct delayed_work, work);
+ struct tca6416_keypad_chip *chip =
+ container_of(delay_work, struct tca6416_keypad_chip, dwork);
+ struct tca6416_drv_data *ddata = chip->drv_data;
+ uint16_t reg_val, val;
+ int ret, i, pin_index;
+
+ ret = tca6416_read_reg(chip, TCA6416_INPUT, ®_val);
+ if (ret)
+ return;
+
+ reg_val &= chip->pinmask;
+
+ /* Figure out which lines have changed */
+ val = reg_val ^ (chip->reg_input);
+ chip->reg_input = reg_val;
+
+ for (i = 0, pin_index = 0; i < 16; i++) {
+ if (val & (1 << i)) {
+ struct tca6416_button *button = &ddata->data[pin_index];
+ struct input_dev *input = ddata->input;
+ unsigned int type = button->type ?: EV_KEY;
+ int state = ((reg_val & (1 << i)) ? 1 : 0)
+ ^ button->active_low;
+
+ input_event(input, type, button->code, !!state);
+ input_sync(input);
+ }
+
+ if (chip->pinmask & (1 << i))
+ pin_index++;
+ }
+
+ if (chip->use_polling)
+ schedule_delayed_work(&chip->dwork, msecs_to_jiffies(100));
+ else
+ enable_irq(chip->irqnum);
+
+}
+
+
+static int __devinit tca6416_keypad_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct tca6416_keys_platform_data *pdata;
+ struct tca6416_keypad_chip *chip;
+ struct tca6416_drv_data *ddata;
+ struct input_dev *input;
+ int i, ret, pin_index, err;
+ uint16_t reg_val;
+
+ /* Check functionality */
+ err = i2c_check_functionality(client->adapter,
+ I2C_FUNC_SMBUS_BYTE);
+ if (!err) {
+ dev_err(&client->dev, "%s adapter not supported\n",
+ dev_driver_string(&client->adapter->dev));
+ return -ENODEV;
+ }
+
+
+ chip = kzalloc(sizeof(struct tca6416_keypad_chip), GFP_KERNEL);
+ if (chip == NULL)
+ return -ENOMEM;
+
+ pdata = client->dev.platform_data;
+ if (pdata == NULL) {
+ dev_dbg(&client->dev, "no platform data\n");
+ ret = -EINVAL;
+ goto fail1;
+ }
+
+ chip->client = client;
+ chip->pinmask = pdata->pinmask;
+
+ /* initialize cached registers from their original values.
+ * we can't share this chip with another i2c master.
+ */
+ ret = tca6416_read_reg(chip, TCA6416_OUTPUT, &chip->reg_output);
+ if (ret)
+ goto fail1;
+
+ ret = tca6416_read_reg(chip, TCA6416_DIRECTION, &chip->reg_direction);
+ if (ret)
+ goto fail1;
+
+ /* ensure that keypad pins are set to input */
+ reg_val = chip->reg_direction | chip->pinmask;
+ ret = tca6416_write_reg(chip, TCA6416_DIRECTION, reg_val);
+ if (ret)
+ goto fail1;
+
+ ret = tca6416_read_reg(chip, TCA6416_DIRECTION, &chip->reg_direction);
+ if (ret)
+ goto fail1;
+
+ ret = tca6416_read_reg(chip, TCA6416_INPUT, &chip->reg_input);
+ if (ret)
+ goto fail1;
+
+ i2c_set_clientdata(client, chip);
+
+
+ ddata = kzalloc(sizeof(struct tca6416_drv_data) +
+ pdata->nbuttons * sizeof(struct tca6416_button),
+ GFP_KERNEL);
+ if (!ddata) {
+ ret = -ENOMEM;
+ goto fail1;
+ }
+
+ input = input_allocate_device();
+ if (!input) {
+ dev_dbg(&client->dev, "failed to allocate state\n");
+ ret = -ENOMEM;
+ kfree(ddata);
+ goto fail2;
+ }
+
+ input->phys = "tca6416-keys/input0";
+ input->name = client->name;
+ input->dev.parent = &client->dev;
+
+ input->id.bustype = BUS_HOST;
+ input->id.vendor = 0x0001;
+ input->id.product = 0x0001;
+ input->id.version = 0x0100;
+
+ /* Enable auto repeat feature of Linux input subsystem */
+ if (pdata->rep)
+ __set_bit(EV_REP, input->evbit);
+
+ ddata->input = input;
+
+ for (i = 0; i < pdata->nbuttons; i++) {
+ unsigned int type;
+
+ ddata->data[i] = pdata->buttons[i];
+ type = (pdata->buttons[i].type) ?: EV_KEY;
+ input_set_capability(input, type, (pdata->buttons[i].code));
+ }
+
+ chip->drv_data = ddata;
+ chip->use_polling = pdata->use_polling;
+
+ INIT_DELAYED_WORK(&chip->dwork, tca6416_keys_work_func);
+
+ if (!chip->use_polling) {
+ if (pdata->irq_is_gpio)
+ chip->irqnum = gpio_to_irq(client->irq);
+ else
+ chip->irqnum = client->irq;
+
+ ret = request_irq(chip->irqnum, tca6416_keys_isr,
+ IRQF_SHARED | IRQF_TRIGGER_FALLING ,
+ "tca6416-keypad", chip);
+ if (ret) {
+ dev_dbg(&client->dev,
+ "Unable to claim irq %d; error %d\n",
+ chip->irqnum, ret);
+ goto fail3;
+ }
+ disable_irq(chip->irqnum);
+ }
+
+ ret = input_register_device(input);
+ if (ret) {
+ dev_dbg(&client->dev, "Unable to register input device, "
+ "error: %d\n", ret);
+ goto fail4;
+ }
+
+ /* get current state of buttons */
+
+ ret = tca6416_read_reg(chip, TCA6416_INPUT, ®_val);
+ if (ret)
+ goto fail5;
+
+ chip->reg_input = reg_val & chip->pinmask;
+
+ for (i = 0, pin_index = 0; i < 16; i++) {
+ if (chip->pinmask & (1 << i)) {
+ struct tca6416_button *button = &ddata->data[pin_index];
+ unsigned int type = button->type ?: EV_KEY;
+ int state = ((reg_val & (1 << i)) ? 1 : 0)
+ ^ button->active_low;
+
+ input_event(input, type, button->code, !!state);
+ input_sync(input);
+ pin_index++;
+ }
+ }
+ input_sync(input);
+
+ if (chip->use_polling)
+ schedule_delayed_work(&chip->dwork, msecs_to_jiffies(100));
+ else
+ enable_irq(chip->irqnum);
+
+ return 0;
+
+fail5:
+ input_unregister_device(input);
+fail4:
+ if (!chip->use_polling)
+ free_irq(chip->irqnum, chip);
+fail3:
+ input_free_device(input);
+fail2:
+ kfree(ddata);
+fail1:
+ kfree(chip);
+ return ret;
+}
+
+static int tca6416_keypad_remove(struct i2c_client *client)
+{
+ struct tca6416_keypad_chip *chip = i2c_get_clientdata(client);
+ struct tca6416_drv_data *ddata = chip->drv_data;
+ struct input_dev *input = ddata->input;
+
+ if (!chip->use_polling)
+ free_irq(chip->irqnum, chip);
+ cancel_delayed_work_sync(&chip->dwork);
+ input_unregister_device(input);
+ input_free_device(input);
+ kfree(ddata);
+ kfree(chip);
+ return 0;
+}
+
+
+static struct i2c_driver tca6416_keypad_driver = {
+ .driver = {
+ .name = "tca6416-keypad",
+ },
+ .probe = tca6416_keypad_probe,
+ .remove = tca6416_keypad_remove,
+ .id_table = tca6416_id,
+};
+
+static int __init tca6416_keypad_init(void)
+{
+ return i2c_add_driver(&tca6416_keypad_driver);
+}
+
+subsys_initcall(tca6416_keypad_init);
+
+static void __exit tca6416_keypad_exit(void)
+{
+ i2c_del_driver(&tca6416_keypad_driver);
+}
+module_exit(tca6416_keypad_exit);
+
+MODULE_AUTHOR("Sriramakrishnan <srk@xxxxxx>");
+MODULE_DESCRIPTION("Keypad driver over tca6146 IO expander");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/tca6416_keypad.h b/include/linux/tca6416_keypad.h
new file mode 100644
index 0000000..7bd266f
--- /dev/null
+++ b/include/linux/tca6416_keypad.h
@@ -0,0 +1,34 @@
+/*
+ * tca6416 keypad platform support
+ *
+ * Copyright (C) 2010 Texas Instruments
+ *
+ * Author: Sriramakrishnan <srk@xxxxxx>
+ *
+ * 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.
+ */
+
+#ifndef _TCA6416_KEYS_H
+#define _TCA6416_KEYS_H
+
+#include <linux/types.h>
+
+struct tca6416_button {
+ /* Configuration parameters */
+ int code; /* input event code (KEY_*, SW_*) */
+ int active_low;
+ int type; /* input event type (EV_KEY, EV_SW) */
+};
+
+struct tca6416_keys_platform_data {
+ struct tca6416_button *buttons;
+ int nbuttons;
+ unsigned int rep:1; /* enable input subsystem auto repeat */
+ uint16_t pinmask;
+ uint16_t invert;
+ int irq_is_gpio;
+ int use_polling; /* use polling if Interrupt is not connected*/
+};
+#endif
--
1.6.2.4
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