1 files changed, 349 insertions, 0 deletions

diff --git a/drivers/input/keyboard/tca6416-keypad.c b/drivers/input/keyboard/tca6416-keypad.c
new file mode 100644
index 000000000000..493c93f25e2a
--- /dev/null
+++ b/drivers/input/keyboard/tca6416-keypad.c
@@ -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");