drivers/input/joystick/adafruit-seesaw.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Copyright (C) 2023 Anshul Dalal <anshulusr@gmail.com>
  *
  * Driver for Adafruit Mini I2C Gamepad
  *
  * Based on the work of:
  *	Oleh Kravchenko (Sparkfun Qwiic Joystick driver)
  *
  * Datasheet: https://cdn-learn.adafruit.com/downloads/pdf/gamepad-qt.pdf
  * Product page: https://www.adafruit.com/product/5743
  * Firmware and hardware sources: https://github.com/adafruit/Adafruit_Seesaw
  *
  * TODO:
  *	- Add interrupt support
  */

 #include <asm/unaligned.h>
 #include <linux/bits.h>
 #include <linux/delay.h>
 #include <linux/i2c.h>
 #include <linux/input.h>
 #include <linux/input/sparse-keymap.h>
 #include <linux/kernel.h>
 #include <linux/module.h>

 #define SEESAW_DEVICE_NAME		"seesaw-gamepad"

 #define SEESAW_ADC_BASE			0x0900

 #define SEESAW_GPIO_DIRCLR_BULK		0x0103
 #define SEESAW_GPIO_BULK		0x0104
 #define SEESAW_GPIO_BULK_SET		0x0105
 #define SEESAW_GPIO_PULLENSET		0x010b

 #define SEESAW_STATUS_HW_ID		0x0001
 #define SEESAW_STATUS_SWRST		0x007f

 #define SEESAW_ADC_OFFSET		0x07

 #define SEESAW_BUTTON_A			0x05
 #define SEESAW_BUTTON_B			0x01
 #define SEESAW_BUTTON_X			0x06
 #define SEESAW_BUTTON_Y			0x02
 #define SEESAW_BUTTON_START		0x10
 #define SEESAW_BUTTON_SELECT		0x00

 #define SEESAW_ANALOG_X			0x0e
 #define SEESAW_ANALOG_Y			0x0f

 #define SEESAW_JOYSTICK_MAX_AXIS	1023
 #define SEESAW_JOYSTICK_FUZZ		2
 #define SEESAW_JOYSTICK_FLAT		4

 #define SEESAW_GAMEPAD_POLL_INTERVAL_MS	16
 #define SEESAW_GAMEPAD_POLL_MIN		8
 #define SEESAW_GAMEPAD_POLL_MAX		32

 static const unsigned long SEESAW_BUTTON_MASK =
 	BIT(SEESAW_BUTTON_A) | BIT(SEESAW_BUTTON_B) | BIT(SEESAW_BUTTON_X) |
 	BIT(SEESAW_BUTTON_Y) | BIT(SEESAW_BUTTON_START) |
 	BIT(SEESAW_BUTTON_SELECT);

 struct seesaw_gamepad {
 	struct input_dev *input_dev;
 	struct i2c_client *i2c_client;
 };

 struct seesaw_data {
 	u16 x;
 	u16 y;
 	u32 button_state;
 };

 static const struct key_entry seesaw_buttons_new[] = {
 	{ KE_KEY, SEESAW_BUTTON_A, .keycode = BTN_SOUTH },
 	{ KE_KEY, SEESAW_BUTTON_B, .keycode = BTN_EAST },
 	{ KE_KEY, SEESAW_BUTTON_X, .keycode = BTN_NORTH },
 	{ KE_KEY, SEESAW_BUTTON_Y, .keycode = BTN_WEST },
 	{ KE_KEY, SEESAW_BUTTON_START, .keycode = BTN_START },
 	{ KE_KEY, SEESAW_BUTTON_SELECT, .keycode = BTN_SELECT },
 	{ KE_END, 0 }
 };

 static int seesaw_register_read(struct i2c_client *client, u16 reg, void *buf,
 				int count)
 {
 	__be16 register_buf = cpu_to_be16(reg);
 	struct i2c_msg message_buf[2] = {
 		{
 			.addr = client->addr,
 			.flags = client->flags,
 			.len = sizeof(register_buf),
 			.buf = (u8 *)&register_buf,
 		},
 		{
 			.addr = client->addr,
 			.flags = client->flags | I2C_M_RD,
 			.len = count,
 			.buf = (u8 *)buf,
 		},
 	};
 	int ret;

 	ret = i2c_transfer(client->adapter, message_buf,
 			   ARRAY_SIZE(message_buf));
 	if (ret < 0)
 		return ret;

 	return 0;
 }

 static int seesaw_register_write_u8(struct i2c_client *client, u16 reg,
 				    u8 value)
 {
 	u8 write_buf[sizeof(reg) + sizeof(value)];
 	int ret;

 	put_unaligned_be16(reg, write_buf);
 	write_buf[sizeof(reg)] = value;

 	ret = i2c_master_send(client, write_buf, sizeof(write_buf));
 	if (ret < 0)
 		return ret;

 	return 0;
 }

 static int seesaw_register_write_u32(struct i2c_client *client, u16 reg,
 				     u32 value)
 {
 	u8 write_buf[sizeof(reg) + sizeof(value)];
 	int ret;

 	put_unaligned_be16(reg, write_buf);
 	put_unaligned_be32(value, write_buf + sizeof(reg));
 	ret = i2c_master_send(client, write_buf, sizeof(write_buf));
 	if (ret < 0)
 		return ret;

 	return 0;
 }

 static int seesaw_read_data(struct i2c_client *client, struct seesaw_data *data)
 {
 	__be16 adc_data;
 	__be32 read_buf;
 	int err;

 	err = seesaw_register_read(client, SEESAW_GPIO_BULK,
 				   &read_buf, sizeof(read_buf));
 	if (err)
 		return err;

 	data->button_state = ~be32_to_cpu(read_buf);

 	err = seesaw_register_read(client,
 				   SEESAW_ADC_BASE |
 					(SEESAW_ADC_OFFSET + SEESAW_ANALOG_X),
 				   &adc_data, sizeof(adc_data));
 	if (err)
 		return err;
 	/*
 	 * ADC reads left as max and right as 0, must be reversed since kernel
 	 * expects reports in opposite order.
 	 */
 	data->x = SEESAW_JOYSTICK_MAX_AXIS - be16_to_cpu(adc_data);

 	err = seesaw_register_read(client,
 				   SEESAW_ADC_BASE |
 					(SEESAW_ADC_OFFSET + SEESAW_ANALOG_Y),
 				   &adc_data, sizeof(adc_data));
 	if (err)
 		return err;

 	data->y = be16_to_cpu(adc_data);

 	return 0;
 }

 static void seesaw_poll(struct input_dev *input)
 {
 	struct seesaw_gamepad *private = input_get_drvdata(input);
 	struct seesaw_data data;
 	int err, i;

 	err = seesaw_read_data(private->i2c_client, &data);
 	if (err) {
 		dev_err_ratelimited(&input->dev,
 				    "failed to read joystick state: %d\n", err);
 		return;
 	}

 	input_report_abs(input, ABS_X, data.x);
 	input_report_abs(input, ABS_Y, data.y);

 	for_each_set_bit(i, &SEESAW_BUTTON_MASK,
 			 BITS_PER_TYPE(SEESAW_BUTTON_MASK)) {
 		if (!sparse_keymap_report_event(input, i,
 						data.button_state & BIT(i),
 						false))
 			dev_err_ratelimited(&input->dev,
 					    "failed to report keymap event");
 	}

 	input_sync(input);
 }

 static int seesaw_probe(struct i2c_client *client)
 {
 	struct seesaw_gamepad *seesaw;
 	u8 hardware_id;
 	int err;

 	err = seesaw_register_write_u8(client, SEESAW_STATUS_SWRST, 0xFF);
 	if (err)
 		return err;

 	/* Wait for the registers to reset before proceeding */
 	usleep_range(10000, 15000);

 	seesaw = devm_kzalloc(&client->dev, sizeof(*seesaw), GFP_KERNEL);
 	if (!seesaw)
 		return -ENOMEM;

 	err = seesaw_register_read(client, SEESAW_STATUS_HW_ID,
 				   &hardware_id, sizeof(hardware_id));
 	if (err)
 		return err;

 	dev_dbg(&client->dev, "Adafruit Seesaw Gamepad, Hardware ID: %02x\n",
 		hardware_id);

 	/* Set Pin Mode to input and enable pull-up resistors */
 	err = seesaw_register_write_u32(client, SEESAW_GPIO_DIRCLR_BULK,
 					SEESAW_BUTTON_MASK);
 	if (err)
 		return err;
 	err = seesaw_register_write_u32(client, SEESAW_GPIO_PULLENSET,
 					SEESAW_BUTTON_MASK);
 	if (err)
 		return err;
 	err = seesaw_register_write_u32(client, SEESAW_GPIO_BULK_SET,
 					SEESAW_BUTTON_MASK);
 	if (err)
 		return err;

 	seesaw->i2c_client = client;
 	seesaw->input_dev = devm_input_allocate_device(&client->dev);
 	if (!seesaw->input_dev)
 		return -ENOMEM;

 	seesaw->input_dev->id.bustype = BUS_I2C;
 	seesaw->input_dev->name = "Adafruit Seesaw Gamepad";
 	seesaw->input_dev->phys = "i2c/" SEESAW_DEVICE_NAME;
 	input_set_drvdata(seesaw->input_dev, seesaw);
 	input_set_abs_params(seesaw->input_dev, ABS_X,
 			     0, SEESAW_JOYSTICK_MAX_AXIS,
 			     SEESAW_JOYSTICK_FUZZ, SEESAW_JOYSTICK_FLAT);
 	input_set_abs_params(seesaw->input_dev, ABS_Y,
 			     0, SEESAW_JOYSTICK_MAX_AXIS,
 			     SEESAW_JOYSTICK_FUZZ, SEESAW_JOYSTICK_FLAT);

 	err = sparse_keymap_setup(seesaw->input_dev, seesaw_buttons_new, NULL);
 	if (err) {
 		dev_err(&client->dev,
 			"failed to set up input device keymap: %d\n", err);
 		return err;
 	}

 	err = input_setup_polling(seesaw->input_dev, seesaw_poll);
 	if (err) {
 		dev_err(&client->dev, "failed to set up polling: %d\n", err);
 		return err;
 	}

 	input_set_poll_interval(seesaw->input_dev,
 				SEESAW_GAMEPAD_POLL_INTERVAL_MS);
 	input_set_max_poll_interval(seesaw->input_dev, SEESAW_GAMEPAD_POLL_MAX);
 	input_set_min_poll_interval(seesaw->input_dev, SEESAW_GAMEPAD_POLL_MIN);

 	err = input_register_device(seesaw->input_dev);
 	if (err) {
 		dev_err(&client->dev, "failed to register joystick: %d\n", err);
 		return err;
 	}

 	return 0;
 }

 static const struct i2c_device_id seesaw_id_table[] = {
 	{ SEESAW_DEVICE_NAME },
 	{ /* Sentinel */ }
 };
 MODULE_DEVICE_TABLE(i2c, seesaw_id_table);

 static const struct of_device_id seesaw_of_table[] = {
 	{ .compatible = "adafruit,seesaw-gamepad"},
 	{ /* Sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, seesaw_of_table);

 static struct i2c_driver seesaw_driver = {
 	.driver = {
 		.name = SEESAW_DEVICE_NAME,
 		.of_match_table = seesaw_of_table,
 	},
 	.id_table = seesaw_id_table,
 	.probe = seesaw_probe,
 };
 module_i2c_driver(seesaw_driver);

 MODULE_AUTHOR("Anshul Dalal <anshulusr@gmail.com>");
 MODULE_DESCRIPTION("Adafruit Mini I2C Gamepad driver");
 MODULE_LICENSE("GPL");
	// SPDX-License-Identifier: GPL-2.0-or-later
	/*
	* Copyright (C) 2023 Anshul Dalal <anshulusr@gmail.com>
	*
	* Driver for Adafruit Mini I2C Gamepad
	*
	* Based on the work of:
	* Oleh Kravchenko (Sparkfun Qwiic Joystick driver)
	*
	* Datasheet: https://cdn-learn.adafruit.com/downloads/pdf/gamepad-qt.pdf
	* Product page: https://www.adafruit.com/product/5743
	* Firmware and hardware sources: https://github.com/adafruit/Adafruit_Seesaw
	*
	* TODO:
	* - Add interrupt support
	*/

	#include <asm/unaligned.h>
	#include <linux/bits.h>
	#include <linux/delay.h>
	#include <linux/i2c.h>
	#include <linux/input.h>
	#include <linux/input/sparse-keymap.h>
	#include <linux/kernel.h>
	#include <linux/module.h>

	#define SEESAW_DEVICE_NAME "seesaw-gamepad"

	#define SEESAW_ADC_BASE 0x0900

	#define SEESAW_GPIO_DIRCLR_BULK 0x0103
	#define SEESAW_GPIO_BULK 0x0104
	#define SEESAW_GPIO_BULK_SET 0x0105
	#define SEESAW_GPIO_PULLENSET 0x010b

	#define SEESAW_STATUS_HW_ID 0x0001
	#define SEESAW_STATUS_SWRST 0x007f

	#define SEESAW_ADC_OFFSET 0x07

	#define SEESAW_BUTTON_A 0x05
	#define SEESAW_BUTTON_B 0x01
	#define SEESAW_BUTTON_X 0x06
	#define SEESAW_BUTTON_Y 0x02
	#define SEESAW_BUTTON_START 0x10
	#define SEESAW_BUTTON_SELECT 0x00

	#define SEESAW_ANALOG_X 0x0e
	#define SEESAW_ANALOG_Y 0x0f

	#define SEESAW_JOYSTICK_MAX_AXIS 1023
	#define SEESAW_JOYSTICK_FUZZ 2
	#define SEESAW_JOYSTICK_FLAT 4

	#define SEESAW_GAMEPAD_POLL_INTERVAL_MS 16
	#define SEESAW_GAMEPAD_POLL_MIN 8
	#define SEESAW_GAMEPAD_POLL_MAX 32

	static const unsigned long SEESAW_BUTTON_MASK =
	BIT(SEESAW_BUTTON_A) \| BIT(SEESAW_BUTTON_B) \| BIT(SEESAW_BUTTON_X) \|
	BIT(SEESAW_BUTTON_Y) \| BIT(SEESAW_BUTTON_START) \|
	BIT(SEESAW_BUTTON_SELECT);

	struct seesaw_gamepad {
	struct input_dev *input_dev;
	struct i2c_client *i2c_client;
	};

	struct seesaw_data {
	u16 x;
	u16 y;
	u32 button_state;
	};

	static const struct key_entry seesaw_buttons_new[] = {
	{ KE_KEY, SEESAW_BUTTON_A, .keycode = BTN_SOUTH },
	{ KE_KEY, SEESAW_BUTTON_B, .keycode = BTN_EAST },
	{ KE_KEY, SEESAW_BUTTON_X, .keycode = BTN_NORTH },
	{ KE_KEY, SEESAW_BUTTON_Y, .keycode = BTN_WEST },
	{ KE_KEY, SEESAW_BUTTON_START, .keycode = BTN_START },
	{ KE_KEY, SEESAW_BUTTON_SELECT, .keycode = BTN_SELECT },
	{ KE_END, 0 }
	};

	static int seesaw_register_read(struct i2c_client client, u16 reg, void buf,
	int count)
	{
	__be16 register_buf = cpu_to_be16(reg);
	struct i2c_msg message_buf[2] = {
	{
	.addr = client->addr,
	.flags = client->flags,
	.len = sizeof(register_buf),
	.buf = (u8 *)&register_buf,
	},
	{
	.addr = client->addr,
	.flags = client->flags \| I2C_M_RD,
	.len = count,
	.buf = (u8 *)buf,
	},
	};
	int ret;

	ret = i2c_transfer(client->adapter, message_buf,
	ARRAY_SIZE(message_buf));
	if (ret < 0)
	return ret;

	return 0;
	}

	static int seesaw_register_write_u8(struct i2c_client *client, u16 reg,
	u8 value)
	{
	u8 write_buf[sizeof(reg) + sizeof(value)];
	int ret;

	put_unaligned_be16(reg, write_buf);
	write_buf[sizeof(reg)] = value;

	ret = i2c_master_send(client, write_buf, sizeof(write_buf));
	if (ret < 0)
	return ret;

	return 0;
	}

	static int seesaw_register_write_u32(struct i2c_client *client, u16 reg,
	u32 value)
	{
	u8 write_buf[sizeof(reg) + sizeof(value)];
	int ret;

	put_unaligned_be16(reg, write_buf);
	put_unaligned_be32(value, write_buf + sizeof(reg));
	ret = i2c_master_send(client, write_buf, sizeof(write_buf));
	if (ret < 0)
	return ret;

	return 0;
	}

	static int seesaw_read_data(struct i2c_client client, struct seesaw_data data)
	{
	__be16 adc_data;
	__be32 read_buf;
	int err;

	err = seesaw_register_read(client, SEESAW_GPIO_BULK,
	&read_buf, sizeof(read_buf));
	if (err)
	return err;

	data->button_state = ~be32_to_cpu(read_buf);

	err = seesaw_register_read(client,
	SEESAW_ADC_BASE \|
	(SEESAW_ADC_OFFSET + SEESAW_ANALOG_X),
	&adc_data, sizeof(adc_data));
	if (err)
	return err;
	/*
	* ADC reads left as max and right as 0, must be reversed since kernel
	* expects reports in opposite order.
	*/
	data->x = SEESAW_JOYSTICK_MAX_AXIS - be16_to_cpu(adc_data);

	err = seesaw_register_read(client,
	SEESAW_ADC_BASE \|
	(SEESAW_ADC_OFFSET + SEESAW_ANALOG_Y),
	&adc_data, sizeof(adc_data));
	if (err)
	return err;

	data->y = be16_to_cpu(adc_data);

	return 0;
	}

	static void seesaw_poll(struct input_dev *input)
	{
	struct seesaw_gamepad *private = input_get_drvdata(input);
	struct seesaw_data data;
	int err, i;

	err = seesaw_read_data(private->i2c_client, &data);
	if (err) {
	dev_err_ratelimited(&input->dev,
	"failed to read joystick state: %d\n", err);
	return;
	}

	input_report_abs(input, ABS_X, data.x);
	input_report_abs(input, ABS_Y, data.y);

	for_each_set_bit(i, &SEESAW_BUTTON_MASK,
	BITS_PER_TYPE(SEESAW_BUTTON_MASK)) {
	if (!sparse_keymap_report_event(input, i,
	data.button_state & BIT(i),
	false))
	dev_err_ratelimited(&input->dev,
	"failed to report keymap event");
	}

	input_sync(input);
	}

	static int seesaw_probe(struct i2c_client *client)
	{
	struct seesaw_gamepad *seesaw;
	u8 hardware_id;
	int err;

	err = seesaw_register_write_u8(client, SEESAW_STATUS_SWRST, 0xFF);
	if (err)
	return err;

	/* Wait for the registers to reset before proceeding */
	usleep_range(10000, 15000);

	seesaw = devm_kzalloc(&client->dev, sizeof(*seesaw), GFP_KERNEL);
	if (!seesaw)
	return -ENOMEM;

	err = seesaw_register_read(client, SEESAW_STATUS_HW_ID,
	&hardware_id, sizeof(hardware_id));
	if (err)
	return err;

	dev_dbg(&client->dev, "Adafruit Seesaw Gamepad, Hardware ID: %02x\n",
	hardware_id);

	/* Set Pin Mode to input and enable pull-up resistors */
	err = seesaw_register_write_u32(client, SEESAW_GPIO_DIRCLR_BULK,
	SEESAW_BUTTON_MASK);
	if (err)
	return err;
	err = seesaw_register_write_u32(client, SEESAW_GPIO_PULLENSET,
	SEESAW_BUTTON_MASK);
	if (err)
	return err;
	err = seesaw_register_write_u32(client, SEESAW_GPIO_BULK_SET,
	SEESAW_BUTTON_MASK);
	if (err)
	return err;

	seesaw->i2c_client = client;
	seesaw->input_dev = devm_input_allocate_device(&client->dev);
	if (!seesaw->input_dev)
	return -ENOMEM;

	seesaw->input_dev->id.bustype = BUS_I2C;
	seesaw->input_dev->name = "Adafruit Seesaw Gamepad";
	seesaw->input_dev->phys = "i2c/" SEESAW_DEVICE_NAME;
	input_set_drvdata(seesaw->input_dev, seesaw);
	input_set_abs_params(seesaw->input_dev, ABS_X,
	0, SEESAW_JOYSTICK_MAX_AXIS,
	SEESAW_JOYSTICK_FUZZ, SEESAW_JOYSTICK_FLAT);
	input_set_abs_params(seesaw->input_dev, ABS_Y,
	0, SEESAW_JOYSTICK_MAX_AXIS,
	SEESAW_JOYSTICK_FUZZ, SEESAW_JOYSTICK_FLAT);

	err = sparse_keymap_setup(seesaw->input_dev, seesaw_buttons_new, NULL);
	if (err) {
	dev_err(&client->dev,
	"failed to set up input device keymap: %d\n", err);
	return err;
	}

	err = input_setup_polling(seesaw->input_dev, seesaw_poll);
	if (err) {
	dev_err(&client->dev, "failed to set up polling: %d\n", err);
	return err;
	}

	input_set_poll_interval(seesaw->input_dev,
	SEESAW_GAMEPAD_POLL_INTERVAL_MS);
	input_set_max_poll_interval(seesaw->input_dev, SEESAW_GAMEPAD_POLL_MAX);
	input_set_min_poll_interval(seesaw->input_dev, SEESAW_GAMEPAD_POLL_MIN);

	err = input_register_device(seesaw->input_dev);
	if (err) {
	dev_err(&client->dev, "failed to register joystick: %d\n", err);
	return err;
	}

	return 0;
	}

	static const struct i2c_device_id seesaw_id_table[] = {
	{ SEESAW_DEVICE_NAME },
	{ /* Sentinel */ }
	};
	MODULE_DEVICE_TABLE(i2c, seesaw_id_table);

	static const struct of_device_id seesaw_of_table[] = {
	{ .compatible = "adafruit,seesaw-gamepad"},
	{ /* Sentinel */ }
	};
	MODULE_DEVICE_TABLE(of, seesaw_of_table);

	static struct i2c_driver seesaw_driver = {
	.driver = {
	.name = SEESAW_DEVICE_NAME,
	.of_match_table = seesaw_of_table,
	},
	.id_table = seesaw_id_table,
	.probe = seesaw_probe,
	};
	module_i2c_driver(seesaw_driver);

	MODULE_AUTHOR("Anshul Dalal <anshulusr@gmail.com>");
	MODULE_DESCRIPTION("Adafruit Mini I2C Gamepad driver");
	MODULE_LICENSE("GPL");