--- /dev/null
+/*
+ * 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, ®_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");
projects / GitHub / LineageOS / android_kernel_motorola_exynos9610.git / commitdiff