drivers/input/keyboard/tca6416-keypad.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Driver for keys on TCA6416 I2C IO expander
  *
  * Copyright (C) 2010 Texas Instruments
  *
  * Author : Sriramakrishnan.A.G. <srk@ti.com>
  */

 #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/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

 #define TCA6416_POLL_INTERVAL	100 /* msec */

 static const struct i2c_device_id tca6416_id[] = {
 	{ "tca6416-keys", 16, },
 	{ "tca6408-keys", 8, },
 	{ }
 };
 MODULE_DEVICE_TABLE(i2c, tca6416_id);

 struct tca6416_drv_data {
 	struct input_dev *input;
 	struct tca6416_button data[];
 };

 struct tca6416_keypad_chip {
 	uint16_t reg_output;
 	uint16_t reg_direction;
 	uint16_t reg_input;

 	struct i2c_client *client;
 	struct input_dev *input;
 	int io_size;
 	int irqnum;
 	u16 pinmask;
 	bool use_polling;
 	struct tca6416_button buttons[];
 };

 static int tca6416_write_reg(struct tca6416_keypad_chip *chip, int reg, u16 val)
 {
 	int error;

 	error = chip->io_size > 8 ?
 		i2c_smbus_write_word_data(chip->client, reg << 1, val) :
 		i2c_smbus_write_byte_data(chip->client, reg, 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 = chip->io_size > 8 ?
 		 i2c_smbus_read_word_data(chip->client, reg << 1) :
 		 i2c_smbus_read_byte_data(chip->client, reg);
 	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 input_dev *input)
 {
 	struct tca6416_keypad_chip *chip = input_get_drvdata(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)
 {
 	tca6416_keys_scan(dev_id);

 	return IRQ_HANDLED;
 }

 static int tca6416_keys_open(struct input_dev *dev)
 {
 	struct tca6416_keypad_chip *chip = input_get_drvdata(dev);

 	if (!chip->use_polling) {
 		/* Get initial device state in case it has switches */
 		tca6416_keys_scan(dev);
 		enable_irq(chip->client->irq);
 	}

 	return 0;
 }

 static void tca6416_keys_close(struct input_dev *dev)
 {
 	struct tca6416_keypad_chip *chip = input_get_drvdata(dev);

 	if (!chip->use_polling)
 		disable_irq(chip->client->irq);
 }

 static int 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 tca6416_keypad_probe(struct i2c_client *client)
 {
 	const struct i2c_device_id *id = i2c_client_get_device_id(client);
 	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 = dev_get_platdata(&client->dev);
 	if (!pdata) {
 		dev_dbg(&client->dev, "no platform data\n");
 		return -EINVAL;
 	}

 	chip = devm_kzalloc(&client->dev,
 			    struct_size(chip, buttons, pdata->nbuttons),
 			    GFP_KERNEL);
 	if (!chip)
 		return -ENOMEM;

 	input = devm_input_allocate_device(&client->dev);
 	if (!input)
 		return -ENOMEM;

 	chip->client = client;
 	chip->input = input;
 	chip->io_size = id->driver_data;
 	chip->pinmask = pdata->pinmask;
 	chip->use_polling = pdata->use_polling;

 	input->phys = "tca6416-keys/input0";
 	input->name = client->name;

 	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)
 		return error;

 	if (chip->use_polling) {
 		error = input_setup_polling(input, tca6416_keys_scan);
 		if (error) {
 			dev_err(&client->dev, "Failed to setup polling\n");
 			return error;
 		}

 		input_set_poll_interval(input, TCA6416_POLL_INTERVAL);
 	} else {
 		error = devm_request_threaded_irq(&client->dev, client->irq,
 						  NULL, tca6416_keys_isr,
 						  IRQF_TRIGGER_FALLING |
 							IRQF_ONESHOT |
 							IRQF_NO_AUTOEN,
 						  "tca6416-keypad", input);
 		if (error) {
 			dev_dbg(&client->dev,
 				"Unable to claim irq %d; error %d\n",
 				client->irq, error);
 			return error;
 		}
 	}

 	error = input_register_device(input);
 	if (error) {
 		dev_dbg(&client->dev,
 			"Unable to register input device, error: %d\n", error);
 		return error;
 	}

 	i2c_set_clientdata(client, chip);

 	return 0;
 }

 static struct i2c_driver tca6416_keypad_driver = {
 	.driver = {
 		.name	= "tca6416-keypad",
 	},
 	.probe		= tca6416_keypad_probe,
 	.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 tca6416 IO expander");
 MODULE_LICENSE("GPL");
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* Driver for keys on TCA6416 I2C IO expander
	*
	* Copyright (C) 2010 Texas Instruments
	*
	* Author : Sriramakrishnan.A.G. <srk@ti.com>
	*/

	#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/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

	#define TCA6416_POLL_INTERVAL 100 /* msec */

	static const struct i2c_device_id tca6416_id[] = {
	{ "tca6416-keys", 16, },
	{ "tca6408-keys", 8, },
	{ }
	};
	MODULE_DEVICE_TABLE(i2c, tca6416_id);

	struct tca6416_drv_data {
	struct input_dev *input;
	struct tca6416_button data[];
	};

	struct tca6416_keypad_chip {
	uint16_t reg_output;
	uint16_t reg_direction;
	uint16_t reg_input;

	struct i2c_client *client;
	struct input_dev *input;
	int io_size;
	int irqnum;
	u16 pinmask;
	bool use_polling;
	struct tca6416_button buttons[];
	};

	static int tca6416_write_reg(struct tca6416_keypad_chip *chip, int reg, u16 val)
	{
	int error;

	error = chip->io_size > 8 ?
	i2c_smbus_write_word_data(chip->client, reg << 1, val) :
	i2c_smbus_write_byte_data(chip->client, reg, 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 = chip->io_size > 8 ?
	i2c_smbus_read_word_data(chip->client, reg << 1) :
	i2c_smbus_read_byte_data(chip->client, reg);
	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 input_dev *input)
	{
	struct tca6416_keypad_chip *chip = input_get_drvdata(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)
	{
	tca6416_keys_scan(dev_id);

	return IRQ_HANDLED;
	}

	static int tca6416_keys_open(struct input_dev *dev)
	{
	struct tca6416_keypad_chip *chip = input_get_drvdata(dev);

	if (!chip->use_polling) {
	/* Get initial device state in case it has switches */
	tca6416_keys_scan(dev);
	enable_irq(chip->client->irq);
	}

	return 0;
	}

	static void tca6416_keys_close(struct input_dev *dev)
	{
	struct tca6416_keypad_chip *chip = input_get_drvdata(dev);

	if (!chip->use_polling)
	disable_irq(chip->client->irq);
	}

	static int 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 tca6416_keypad_probe(struct i2c_client *client)
	{
	const struct i2c_device_id *id = i2c_client_get_device_id(client);
	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 = dev_get_platdata(&client->dev);
	if (!pdata) {
	dev_dbg(&client->dev, "no platform data\n");
	return -EINVAL;
	}

	chip = devm_kzalloc(&client->dev,
	struct_size(chip, buttons, pdata->nbuttons),
	GFP_KERNEL);
	if (!chip)
	return -ENOMEM;

	input = devm_input_allocate_device(&client->dev);
	if (!input)
	return -ENOMEM;

	chip->client = client;
	chip->input = input;
	chip->io_size = id->driver_data;
	chip->pinmask = pdata->pinmask;
	chip->use_polling = pdata->use_polling;

	input->phys = "tca6416-keys/input0";
	input->name = client->name;

	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)
	return error;

	if (chip->use_polling) {
	error = input_setup_polling(input, tca6416_keys_scan);
	if (error) {
	dev_err(&client->dev, "Failed to setup polling\n");
	return error;
	}

	input_set_poll_interval(input, TCA6416_POLL_INTERVAL);
	} else {
	error = devm_request_threaded_irq(&client->dev, client->irq,
	NULL, tca6416_keys_isr,
	IRQF_TRIGGER_FALLING \|
	IRQF_ONESHOT \|
	IRQF_NO_AUTOEN,
	"tca6416-keypad", input);
	if (error) {
	dev_dbg(&client->dev,
	"Unable to claim irq %d; error %d\n",
	client->irq, error);
	return error;
	}
	}

	error = input_register_device(input);
	if (error) {
	dev_dbg(&client->dev,
	"Unable to register input device, error: %d\n", error);
	return error;
	}

	i2c_set_clientdata(client, chip);

	return 0;
	}

	static struct i2c_driver tca6416_keypad_driver = {
	.driver = {
	.name = "tca6416-keypad",
	},
	.probe = tca6416_keypad_probe,
	.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 tca6416 IO expander");
	MODULE_LICENSE("GPL");