--- /dev/null
+// 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");
git.samba.org / sfrench / cifs-2.6.git / commitdiff