Input: add keypad driver for keys interfaced to TCA6416
authorSriramakrishnan Govindarajan <srk@ti.com>
Tue, 4 May 2010 06:47:12 +0000 (23:47 -0700)
committerDmitry Torokhov <dmitry.torokhov@gmail.com>
Tue, 4 May 2010 06:50:42 +0000 (23:50 -0700)
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@ti.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
drivers/input/keyboard/Kconfig
drivers/input/keyboard/Makefile
drivers/input/keyboard/tca6416-keypad.c [new file with mode: 0644]
include/linux/tca6416_keypad.h [new file with mode: 0644]

index a8293388d0194084eec2905b4c9c949eece17939..3525f533e186d3f3cf0e7990d9efa4af90a66d85 100644 (file)
@@ -179,6 +179,22 @@ 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
index 9a74127e4d1706fcc35baa0edb21481b0344b79b..4596d0c6f9228cfeca47a6a08ff019d04e353787 100644 (file)
@@ -14,6 +14,7 @@ obj-$(CONFIG_KEYBOARD_BFIN)           += bf54x-keys.o
 obj-$(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 (file)
index 0000000..493c93f
--- /dev/null
@@ -0,0 +1,349 @@
+/*
+ * Driver for keys on TCA6416 I2C IO expander
+ *
+ * Copyright (C) 2010 Texas Instruments
+ *
+ * Author : Sriramakrishnan.A.G. <srk@ti.com>
+ *
+ * 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/types.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/workqueue.h>
+#include <linux/gpio.h>
+#include <linux/i2c.h>
+#include <linux/input.h>
+#include <linux/tca6416_keypad.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 input_dev *input;
+       struct delayed_work dwork;
+       u16 pinmask;
+       int irqnum;
+       bool use_polling;
+       struct tca6416_button buttons[0];
+};
+
+static int tca6416_write_reg(struct tca6416_keypad_chip *chip, int reg, u16 val)
+{
+       int error;
+
+       error = i2c_smbus_write_word_data(chip->client, reg << 1, val);
+       if (error < 0) {
+               dev_err(&chip->client->dev,
+                       "%s failed, reg: %d, val: %d, error: %d\n",
+                       __func__, reg, val, error);
+               return error;
+       }
+
+       return 0;
+}
+
+static int tca6416_read_reg(struct tca6416_keypad_chip *chip, int reg, u16 *val)
+{
+       int retval;
+
+       retval = i2c_smbus_read_word_data(chip->client, reg << 1);
+       if (retval < 0) {
+               dev_err(&chip->client->dev, "%s failed, reg: %d, error: %d\n",
+                       __func__, reg, retval);
+               return retval;
+       }
+
+       *val = (u16)retval;
+       return 0;
+}
+
+static void tca6416_keys_scan(struct tca6416_keypad_chip *chip)
+{
+       struct input_dev *input = chip->input;
+       u16 reg_val, val;
+       int error, i, pin_index;
+
+       error = tca6416_read_reg(chip, TCA6416_INPUT, &reg_val);
+       if (error)
+               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 = &chip->buttons[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);
+               }
+
+               if (chip->pinmask & (1 << i))
+                       pin_index++;
+       }
+}
+
+/*
+ * This is threaded IRQ handler and this can (and will) sleep.
+ */
+static irqreturn_t tca6416_keys_isr(int irq, void *dev_id)
+{
+       struct tca6416_keypad_chip *chip = dev_id;
+
+       tca6416_keys_scan(chip);
+
+       return IRQ_HANDLED;
+}
+
+static void tca6416_keys_work_func(struct work_struct *work)
+{
+       struct tca6416_keypad_chip *chip =
+               container_of(work, struct tca6416_keypad_chip, dwork.work);
+
+       tca6416_keys_scan(chip);
+       schedule_delayed_work(&chip->dwork, msecs_to_jiffies(100));
+}
+
+static int tca6416_keys_open(struct input_dev *dev)
+{
+       struct tca6416_keypad_chip *chip = input_get_drvdata(dev);
+
+       /* Get initial device state in case it has switches */
+       tca6416_keys_scan(chip);
+
+       if (chip->use_polling)
+               schedule_delayed_work(&chip->dwork, msecs_to_jiffies(100));
+       else
+               enable_irq(chip->irqnum);
+
+       return 0;
+}
+
+static void tca6416_keys_close(struct input_dev *dev)
+{
+       struct tca6416_keypad_chip *chip = input_get_drvdata(dev);
+
+       if (chip->use_polling)
+               cancel_delayed_work_sync(&chip->dwork);
+       else
+               disable_irq(chip->irqnum);
+}
+
+static int __devinit tca6416_setup_registers(struct tca6416_keypad_chip *chip)
+{
+       int error;
+
+       error = tca6416_read_reg(chip, TCA6416_OUTPUT, &chip->reg_output);
+       if (error)
+               return error;
+
+       error = tca6416_read_reg(chip, TCA6416_DIRECTION, &chip->reg_direction);
+       if (error)
+               return error;
+
+       /* ensure that keypad pins are set to input */
+       error = tca6416_write_reg(chip, TCA6416_DIRECTION,
+                                 chip->reg_direction | chip->pinmask);
+       if (error)
+               return error;
+
+       error = tca6416_read_reg(chip, TCA6416_DIRECTION, &chip->reg_direction);
+       if (error)
+               return error;
+
+       error = tca6416_read_reg(chip, TCA6416_INPUT, &chip->reg_input);
+       if (error)
+               return error;
+
+       chip->reg_input &= chip->pinmask;
+
+       return 0;
+}
+
+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 input_dev *input;
+       int error;
+       int i;
+
+       /* Check functionality */
+       if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE)) {
+               dev_err(&client->dev, "%s adapter not supported\n",
+                       dev_driver_string(&client->adapter->dev));
+               return -ENODEV;
+       }
+
+       pdata = client->dev.platform_data;
+       if (!pdata) {
+               dev_dbg(&client->dev, "no platform data\n");
+               return -EINVAL;
+       }
+
+       chip = kzalloc(sizeof(struct tca6416_keypad_chip) +
+                      pdata->nbuttons * sizeof(struct tca6416_button),
+                      GFP_KERNEL);
+       input = input_allocate_device();
+       if (!chip || !input) {
+               error = -ENOMEM;
+               goto fail1;
+       }
+
+       chip->client = client;
+       chip->input = input;
+       chip->pinmask = pdata->pinmask;
+       chip->use_polling = pdata->use_polling;
+
+       INIT_DELAYED_WORK(&chip->dwork, tca6416_keys_work_func);
+
+       input->phys = "tca6416-keys/input0";
+       input->name = client->name;
+       input->dev.parent = &client->dev;
+
+       input->open = tca6416_keys_open;
+       input->close = tca6416_keys_close;
+
+       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);
+
+       for (i = 0; i < pdata->nbuttons; i++) {
+               unsigned int type;
+
+               chip->buttons[i] = pdata->buttons[i];
+               type = (pdata->buttons[i].type) ?: EV_KEY;
+               input_set_capability(input, type, pdata->buttons[i].code);
+       }
+
+       input_set_drvdata(input, chip);
+
+       /*
+        * Initialize cached registers from their original values.
+        * we can't share this chip with another i2c master.
+        */
+       error = tca6416_setup_registers(chip);
+       if (error)
+               goto fail1;
+
+       if (!chip->use_polling) {
+               if (pdata->irq_is_gpio)
+                       chip->irqnum = gpio_to_irq(client->irq);
+               else
+                       chip->irqnum = client->irq;
+
+               error = request_threaded_irq(chip->irqnum, NULL,
+                                            tca6416_keys_isr,
+                                            IRQF_TRIGGER_FALLING,
+                                            "tca6416-keypad", chip);
+               if (error) {
+                       dev_dbg(&client->dev,
+                               "Unable to claim irq %d; error %d\n",
+                               chip->irqnum, error);
+                       goto fail1;
+               }
+               disable_irq(chip->irqnum);
+       }
+
+       error = input_register_device(input);
+       if (error) {
+               dev_dbg(&client->dev,
+                       "Unable to register input device, error: %d\n", error);
+               goto fail2;
+       }
+
+       i2c_set_clientdata(client, chip);
+
+       return 0;
+
+fail2:
+       if (!chip->use_polling) {
+               free_irq(chip->irqnum, chip);
+               enable_irq(chip->irqnum);
+       }
+fail1:
+       input_free_device(input);
+       kfree(chip);
+       return error;
+}
+
+static int __devexit tca6416_keypad_remove(struct i2c_client *client)
+{
+       struct tca6416_keypad_chip *chip = i2c_get_clientdata(client);
+
+       if (!chip->use_polling) {
+               free_irq(chip->irqnum, chip);
+               enable_irq(chip->irqnum);
+       }
+
+       input_unregister_device(chip->input);
+       kfree(chip);
+
+       i2c_set_clientdata(client, NULL);
+
+       return 0;
+}
+
+
+static struct i2c_driver tca6416_keypad_driver = {
+       .driver = {
+               .name   = "tca6416-keypad",
+       },
+       .probe          = tca6416_keypad_probe,
+       .remove         = __devexit_p(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@ti.com>");
+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 (file)
index 0000000..7bd266f
--- /dev/null
@@ -0,0 +1,34 @@
+/*
+ * tca6416 keypad platform support
+ *
+ * Copyright (C) 2010 Texas Instruments
+ *
+ * Author: Sriramakrishnan <srk@ti.com>
+ *
+ * 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