Hi, please also Cc linux-kernel@xxxxxxxxxxxxxxx on all patches. Some more comments inline. On 2023-10-08 22:54:34+0530, Anshul Dalal wrote: > A simple driver for a mini gamepad that communicates over i2c, the gamepad > has bidirectional thumb stick input and six buttons. > > The gamepad chip utilizes the open framework from Adafruit called 'Seesaw' > to transmit the ADC data for the joystick and digital pin state for the > buttons. I have only implemented the functionality required to receive the > thumb stick and button state. > > Steps in reading the gamepad state over i2c: > 1. Reset the registers > 2. Set the pin mode of the pins specified by the `BUTTON_MASK` to input > `BUTTON_MASK`: A bit-map for the six digital pins internally > connected to the joystick buttons. > 3. Enable internal pullup resistors for the `BUTTON_MASK` > 4. Bulk set the pin state HIGH for `BUTTON_MASK` > 5. Poll the device for button and joystick state done by: > `seesaw_read_data(struct i2c_client *client, struct seesaw_data *data)` > > Product page: > https://www.adafruit.com/product/5743 > Arduino driver: > https://github.com/adafruit/Adafruit_Seesaw > > Driver tested on RPi Zero 2W > > Signed-off-by: Anshul Dalal <anshulusr@xxxxxxxxx> > --- > > Changes for v2: > adafruit-seesaw.c: > - Renamed file from 'adafruit_seesaw.c' > - Changed device name from 'seesaw_gamepad' to 'seesaw-gamepad' > - Changed count parameter for receiving joystick x on line 118: > `2` to `sizeof(write_buf)` > - Fixed invalid buffer size on line 123 and 126: > `data->y` to `sizeof(data->y)` > - Added comment for the `mdelay(10)` on line 169 > - Changed inconsistent indentation on line 271 > Kconfig: > - Fixed indentation for the help text > - Updated module name > Makefile: > - Updated module object file name > MAINTAINERS: > - Updated file name for the driver and bindings > > MAINTAINERS | 7 + > drivers/input/joystick/Kconfig | 9 + > drivers/input/joystick/Makefile | 1 + > drivers/input/joystick/adafruit-seesaw.c | 277 +++++++++++++++++++++++ > 4 files changed, 294 insertions(+) > create mode 100644 drivers/input/joystick/adafruit-seesaw.c > > diff --git a/MAINTAINERS b/MAINTAINERS > index 81d5fc0bba68..cd4f9deb77e2 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -441,6 +441,13 @@ W: http://wiki.analog.com/AD7879 > W: https://ez.analog.com/linux-software-drivers > F: drivers/input/touchscreen/ad7879.c > > +ADAFRUIT MINI I2C GAMEPAD > +M: Anshul Dalal <anshulusr@xxxxxxxxx> > +L: linux-input@xxxxxxxxxxxxxxx > +S: Maintained > +F: Documentation/devicetree/bindings/input/adafruit,seesaw-gamepad.yaml > +F: drivers/input/joystick/adafruit-seesaw.c > + > ADDRESS SPACE LAYOUT RANDOMIZATION (ASLR) > M: Jiri Kosina <jikos@xxxxxxxxxx> > S: Maintained > diff --git a/drivers/input/joystick/Kconfig b/drivers/input/joystick/Kconfig > index ac6925ce8366..4d4fc38087bf 100644 > --- a/drivers/input/joystick/Kconfig > +++ b/drivers/input/joystick/Kconfig > @@ -412,4 +412,13 @@ config JOYSTICK_SENSEHAT > To compile this driver as a module, choose M here: the > module will be called sensehat_joystick. > > +config JOYSTICK_SEESAW > + tristate "Adafruit Mini I2C Gamepad with Seesaw" > + depends on I2C > + help > + Say Y here if you want to use the Adafruit Mini I2C Gamepad. > + > + To compile this driver as a module, choose M here: the module will be > + called adafruit-seesaw. > + > endif > diff --git a/drivers/input/joystick/Makefile b/drivers/input/joystick/Makefile > index 3937535f0098..fdc653209542 100644 > --- a/drivers/input/joystick/Makefile > +++ b/drivers/input/joystick/Makefile > @@ -28,6 +28,7 @@ obj-$(CONFIG_JOYSTICK_N64) += n64joy.o > obj-$(CONFIG_JOYSTICK_PSXPAD_SPI) += psxpad-spi.o > obj-$(CONFIG_JOYSTICK_PXRC) += pxrc.o > obj-$(CONFIG_JOYSTICK_QWIIC) += qwiic-joystick.o > +obj-$(CONFIG_JOYSTICK_SEESAW) += adafruit-seesaw.o > obj-$(CONFIG_JOYSTICK_SENSEHAT) += sensehat-joystick.o > obj-$(CONFIG_JOYSTICK_SIDEWINDER) += sidewinder.o > obj-$(CONFIG_JOYSTICK_SPACEBALL) += spaceball.o > diff --git a/drivers/input/joystick/adafruit-seesaw.c b/drivers/input/joystick/adafruit-seesaw.c > new file mode 100644 > index 000000000000..1e8b3f5604d8 > --- /dev/null > +++ b/drivers/input/joystick/adafruit-seesaw.c > @@ -0,0 +1,277 @@ > +// SPDX-License-Identifier: GPL-2.0-or-later > +/* > + * Copyright (C) 2023 Anshul Dalal <anshulusr@xxxxxxxxx> > + * > + * Driver for Adafruit Mini I2C Gamepad > + * > + * Based on the work of: > + * Oleh Kravchenko (Sparkfun Qwiic Joystick driver) > + * > + * Product page: https://www.adafruit.com/product/5743 > + * Firmware and hardware sources: https://github.com/adafruit/Adafruit_Seesaw > + */ > + > +#include <linux/bits.h> > +#include <linux/delay.h> > +#include <linux/i2c.h> > +#include <linux/input.h> > +#include <linux/kernel.h> > +#include <linux/module.h> > + > +/* clang-format off */ > +#define SEESAW_DEVICE_NAME "seesaw-gamepad" > + > +#define SEESAW_STATUS_BASE 0 > +#define SEESAW_GPIO_BASE 1 > +#define SEESAW_ADC_BASE 9 > + > +#define SEESAW_GPIO_DIRCLR_BULK 3 > +#define SEESAW_GPIO_BULK 4 > +#define SEESAW_GPIO_BULK_SET 5 > +#define SEESAW_GPIO_PULLENSET 11 > + > +#define SEESAW_STATUS_HW_ID 1 > +#define SEESAW_STATUS_SWRST 127 > + > +#define SEESAW_ADC_OFFSET 7 > + > +#define BUTTON_A 5 > +#define BUTTON_B 1 > +#define BUTTON_X 6 > +#define BUTTON_Y 2 > +#define BUTTON_START 16 > +#define BUTTON_SELECT 0 > + > +#define ANALOG_X 14 > +#define ANALOG_Y 15 > + > +#define SEESAW_JOYSTICK_MAX_AXIS 1023 > +#define SEESAW_JOYSTICK_FUZZ 2 > +#define SEESAW_JOYSTICK_FLAT 4 > + > +#define SEESAW_GAMEPAD_POLL_INTERVAL 16 > +#define SEESAW_GAMEPAD_POLL_MIN 8 > +#define SEESAW_GAMEPAD_POLL_MAX 32 > +/* clang-format on */ > + > +u32 BUTTON_MASK = (1UL << BUTTON_A) | (1UL << BUTTON_B) | (1UL << BUTTON_X) | > + (1UL << BUTTON_Y) | (1UL << BUTTON_START) | > + (1UL << BUTTON_SELECT); BIT(BUTTON_A), etc. Also below. > + > +struct seesaw_gamepad { > + char physical_path[32]; > + unsigned char hardware_id; This can be dropped. > + struct input_dev *input_dev; > + struct i2c_client *i2c_client; > +}; > + > +struct seesaw_data { > + __be16 x; > + __be16 y; > + u8 button_a, button_b, button_x, button_y, button_start, button_select; > +}; > + > +static int seesaw_read_data(struct i2c_client *client, struct seesaw_data *data) > +{ > + int err; > + unsigned char write_buf[2] = { SEESAW_GPIO_BASE, SEESAW_GPIO_BULK }; > + > + unsigned char read_buf[4]; > + > + err = i2c_master_send(client, write_buf, sizeof(write_buf)); > + if (err < 0) > + return err; > + if (err != sizeof(write_buf)) > + return -EIO; The return value of the i2c_master_ APIs should never be != the count parameter. So the addition sizeof() checks can go away. > + err = i2c_master_recv(client, read_buf, sizeof(read_buf)); > + if (err < 0) > + return err; > + if (err != sizeof(read_buf)) > + return -EIO; > + u32 result = ((u32)read_buf[0] << 24) | ((u32)read_buf[1] << 16) | > + ((u32)read_buf[2] << 8) | (u32)read_buf[3]; get_unaligned_be32() > + data->button_a = !(result & (1UL << BUTTON_A)); This should be able to use test_bit(). > + data->button_b = !(result & (1UL << BUTTON_B)); > + data->button_x = !(result & (1UL << BUTTON_X)); > + data->button_y = !(result & (1UL << BUTTON_Y)); > + data->button_start = !(result & (1UL << BUTTON_START)); > + data->button_select = !(result & (1UL << BUTTON_SELECT)); > + > + write_buf[0] = SEESAW_ADC_BASE; > + write_buf[1] = SEESAW_ADC_OFFSET + ANALOG_X; > + err = i2c_master_send(client, write_buf, sizeof(write_buf)); > + if (err < 0) > + return err; > + if (err != sizeof(write_buf)) > + return -EIO; > + err = i2c_master_recv(client, (char *)&data->x, sizeof(data->x)); > + if (err < 0) > + return err; > + if (err != sizeof(data->x)) > + return -EIO; > + /* > + * 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(data->x); > + > + write_buf[1] = SEESAW_ADC_OFFSET + ANALOG_Y; > + err = i2c_master_send(client, write_buf, sizeof(write_buf)); > + if (err < 0) > + return err; > + if (err != sizeof(write_buf)) > + return -EIO; > + err = i2c_master_recv(client, (char *)&data->y, sizeof(data->y)); > + if (err < 0) > + return err; > + if (err != sizeof(data->y)) > + return -EIO; > + data->y = be16_to_cpu(data->y); > + > + return 0; > +} > + > +static void seesaw_poll(struct input_dev *input) > +{ > + struct seesaw_gamepad *private = input_get_drvdata(input); > + struct seesaw_data data; > + int err; > + > + err = seesaw_read_data(private->i2c_client, &data); > + if (err != 0) > + return; > + > + input_report_abs(input, ABS_X, data.x); > + input_report_abs(input, ABS_Y, data.y); > + input_report_key(input, BTN_A, data.button_a); > + input_report_key(input, BTN_B, data.button_b); > + input_report_key(input, BTN_X, data.button_x); > + input_report_key(input, BTN_Y, data.button_y); > + input_report_key(input, BTN_START, data.button_start); > + input_report_key(input, BTN_SELECT, data.button_select); > + input_sync(input); > +} > + > +static int seesaw_probe(struct i2c_client *client) > +{ > + int err; > + struct seesaw_gamepad *private; > + unsigned char register_reset[] = { SEESAW_STATUS_BASE, > + SEESAW_STATUS_SWRST, 0xFF }; > + unsigned char get_hw_id[] = { SEESAW_STATUS_BASE, SEESAW_STATUS_HW_ID }; > + > + err = i2c_master_send(client, register_reset, sizeof(register_reset)); > + if (err < 0) > + return err; > + if (err != sizeof(register_reset)) > + return -EIO; > + > + /* Wait for the registers to reset before proceeding */ > + mdelay(10); > + > + private = devm_kzalloc(&client->dev, sizeof(*private), GFP_KERNEL); > + if (!private) > + return -ENOMEM; > + > + err = i2c_master_send(client, get_hw_id, sizeof(get_hw_id)); > + if (err < 0) > + return err; > + if (err != sizeof(get_hw_id)) > + return -EIO; > + err = i2c_master_recv(client, &private->hardware_id, 1); > + if (err < 0) > + return err; > + if (err != 1) > + return -EIO; > + > + dev_dbg(&client->dev, "Adafruit Seesaw Gamepad, Hardware ID: %02x\n", > + private->hardware_id); > + > + private->i2c_client = client; > + scnprintf(private->physical_path, sizeof(private->physical_path), > + "i2c/%s", dev_name(&client->dev)); > + i2c_set_clientdata(client, private); > + > + private->input_dev = devm_input_allocate_device(&client->dev); > + if (!private->input_dev) > + return -ENOMEM; > + > + private->input_dev->id.bustype = BUS_I2C; > + private->input_dev->name = "Adafruit Seesaw Gamepad"; > + private->input_dev->phys = private->physical_path; > + input_set_drvdata(private->input_dev, private); > + input_set_abs_params(private->input_dev, ABS_X, 0, > + SEESAW_JOYSTICK_MAX_AXIS, SEESAW_JOYSTICK_FUZZ, > + SEESAW_JOYSTICK_FLAT); > + input_set_abs_params(private->input_dev, ABS_Y, 0, > + SEESAW_JOYSTICK_MAX_AXIS, SEESAW_JOYSTICK_FUZZ, > + SEESAW_JOYSTICK_FLAT); > + input_set_capability(private->input_dev, EV_KEY, BTN_A); > + input_set_capability(private->input_dev, EV_KEY, BTN_B); > + input_set_capability(private->input_dev, EV_KEY, BTN_X); > + input_set_capability(private->input_dev, EV_KEY, BTN_Y); > + input_set_capability(private->input_dev, EV_KEY, BTN_START); > + input_set_capability(private->input_dev, EV_KEY, BTN_SELECT); > + > + err = input_setup_polling(private->input_dev, seesaw_poll); > + if (err) { > + dev_err(&client->dev, "failed to set up polling: %d\n", err); > + return err; > + } > + > + input_set_poll_interval(private->input_dev, > + SEESAW_GAMEPAD_POLL_INTERVAL); > + input_set_max_poll_interval(private->input_dev, > + SEESAW_GAMEPAD_POLL_MAX); > + input_set_min_poll_interval(private->input_dev, > + SEESAW_GAMEPAD_POLL_MIN); > + > + err = input_register_device(private->input_dev); > + if (err) { > + dev_err(&client->dev, "failed to register joystick: %d\n", err); > + return err; > + } > + > + /* Set Pin Mode to input and enable pull-up resistors */ > + unsigned char pin_mode[] = { SEESAW_GPIO_BASE, SEESAW_GPIO_DIRCLR_BULK, > + BUTTON_MASK >> 24, BUTTON_MASK >> 16, > + BUTTON_MASK >> 8, BUTTON_MASK }; > + err = i2c_master_send(client, pin_mode, sizeof(pin_mode)); > + pin_mode[1] = SEESAW_GPIO_PULLENSET; > + err |= i2c_master_send(client, pin_mode, sizeof(pin_mode)); This will mangle the errorcode if the calls to i2c_master_send() return different errors. > + pin_mode[1] = SEESAW_GPIO_BULK_SET; > + err |= i2c_master_send(client, pin_mode, sizeof(pin_mode)); > + if (err < 0) > + return err; > + if (err != sizeof(pin_mode)) > + return -EIO; > + > + return 0; > +} > + > +#ifdef CONFIG_OF > +static const struct of_device_id of_seesaw_match[] = { > + { > + .compatible = "adafruit,seesaw-gamepad", > + }, > + { /* Sentinel */ }, No comma after sentinel. > +}; > +MODULE_DEVICE_TABLE(of, of_seesaw_match); > +#endif /* CONFIG_OF */ > + > +static const struct i2c_device_id seesaw_id_table[] = { { KBUILD_MODNAME, 0 }, > + { /* Sentinel */ } }; Borked formatting. Also afaik KBUILD_MODNAME in id-tables is frowned upon. Use the explicit string instead. > +MODULE_DEVICE_TABLE(i2c, seesaw_id_table); > + > +static struct i2c_driver seesaw_driver = { > + .driver = { > + .name = SEESAW_DEVICE_NAME, > + .of_match_table = of_match_ptr(of_seesaw_match), > + }, > + .id_table = seesaw_id_table, > + .probe = seesaw_probe, > +}; > +module_i2c_driver(seesaw_driver); > + > +MODULE_AUTHOR("Anshul Dalal <anshulusr@xxxxxxxxx>"); > +MODULE_DESCRIPTION("Adafruit Mini I2C Gamepad driver"); > +MODULE_LICENSE("GPL"); > -- > 2.42.0 >
