diff options
Diffstat (limited to 'drivers/input/joystick/adafruit-seesaw.c')
-rw-r--r-- | drivers/input/joystick/adafruit-seesaw.c | 315 |
1 files changed, 315 insertions, 0 deletions
diff --git a/drivers/input/joystick/adafruit-seesaw.c b/drivers/input/joystick/adafruit-seesaw.c new file mode 100644 index 0000000000..1b9279f024 --- /dev/null +++ b/drivers/input/joystick/adafruit-seesaw.c @@ -0,0 +1,315 @@ +// 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 *)®ister_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"); 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