| Message ID | 20231008172435.2391009-2-anshulusr@gmail.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v2,1/2] dt-bindings: input: bindings for Adafruit Seesaw Gamepad | expand |
Hi, please also Cc linux-kernel@vger.kernel.org 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@gmail.com> > --- > > 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@gmail.com> > +L: linux-input@vger.kernel.org > +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@kernel.org> > 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@gmail.com> > + * > + * 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@gmail.com>"); > +MODULE_DESCRIPTION("Adafruit Mini I2C Gamepad driver"); > +MODULE_LICENSE("GPL"); > -- > 2.42.0 >
On 2023-10-08 22:54:34+0530, Anshul Dalal wrote: > [..] > + > + 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); FYI the button layout on this device is different from common commercial gamepads like XBox, Playstation and Logitech. This seems to be common to all gamepads from Adafruit. Adafruit: X Y A B Others: Y X B A In input-event-codes.h the symbol BTN_A actually maps to BTN_SOUTH, matching the common layout. But as you can see this is wrong for this device. (Same for BTN_B and BTN_EAST) Weirdly enough for BTN_X/BTN_NORTH and BTN_Y/BNT_WEST the aliasing is correct for Adafruit and wrong for the others. Not sure how to fix this correctly. Maybe the input maintainers know. > + input_report_key(input, BTN_START, data.button_start); > + input_report_key(input, BTN_SELECT, data.button_select); > + input_sync(input); > +}
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@gmail.com> +L: linux-input@vger.kernel.org +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@kernel.org> 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@gmail.com> + * + * 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); + +struct seesaw_gamepad { + char physical_path[32]; + unsigned char hardware_id; + 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; + 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]; + data->button_a = !(result & (1UL << BUTTON_A)); + 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)); + 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 */ }, +}; +MODULE_DEVICE_TABLE(of, of_seesaw_match); +#endif /* CONFIG_OF */ + +static const struct i2c_device_id seesaw_id_table[] = { { KBUILD_MODNAME, 0 }, + { /* Sentinel */ } }; +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@gmail.com>"); +MODULE_DESCRIPTION("Adafruit Mini I2C Gamepad driver"); +MODULE_LICENSE("GPL");
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@gmail.com> --- 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