On Wed, 2022-02-02 at 19:25 -0500, Charles Mirabile wrote: > This patch adds the driver for the Sense HAT joystick. It outputs BTN_DPAD > key events when moved in any of the four directions and the BTN_SELECT > event when depressed. > > Co-developed-by: Mwesigwa Guma <mguma@xxxxxxxxxx> > Signed-off-by: Mwesigwa Guma <mguma@xxxxxxxxxx> > Co-developed-by: Joel Savitz <jsavitz@xxxxxxxxxx> > Signed-off-by: Joel Savitz <jsavitz@xxxxxxxxxx> > Signed-off-by: Charles Mirabile <cmirabil@xxxxxxxxxx> > --- > drivers/input/joystick/Kconfig | 11 ++ > drivers/input/joystick/Makefile | 1 + > drivers/input/joystick/sensehat-joystick.c | 128 +++++++++++++++++++++ > 3 files changed, 140 insertions(+) > create mode 100644 drivers/input/joystick/sensehat-joystick.c > > diff --git a/drivers/input/joystick/Kconfig b/drivers/input/joystick/Kconfig > index 3b23078bc7b5..505a032e2786 100644 > --- a/drivers/input/joystick/Kconfig > +++ b/drivers/input/joystick/Kconfig > @@ -399,4 +399,15 @@ config JOYSTICK_N64 > Say Y here if you want enable support for the four > built-in controller ports on the Nintendo 64 console. > > +config JOYSTICK_SENSEHAT > + tristate "Raspberry Pi Sense HAT joystick" > + depends on INPUT && I2C > + select MFD_SIMPLE_MFD_I2C > + help > + Say Y here if you want to enable the driver for the > + the Raspberry Pi Sense HAT. > + > + To compile this driver as a module, choose M here: the > + module will be called sensehat_joystick. > + > endif > diff --git a/drivers/input/joystick/Makefile b/drivers/input/joystick/Makefile > index 5174b8aba2dd..39c8b5c6e5ae 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-$(CONFIG_JOYSTICK_SENSEHAT) += sensehat-joystick.o > obj-$(CONFIG_JOYSTICK_SIDEWINDER) += sidewinder.o > obj-$(CONFIG_JOYSTICK_SPACEBALL) += spaceball.o > obj-$(CONFIG_JOYSTICK_SPACEORB) += spaceorb.o > diff --git a/drivers/input/joystick/sensehat-joystick.c b/drivers/input/joystick/sensehat-joystick.c > new file mode 100644 > index 000000000000..a688cc8fbde3 > --- /dev/null > +++ b/drivers/input/joystick/sensehat-joystick.c > @@ -0,0 +1,128 @@ > +// SPDX-License-Identifier: GPL-2.0-or-later > +/* > + * Raspberry Pi Sense HAT joystick driver > + * http://raspberrypi.org > + * > + * Copyright (C) 2015 Raspberry Pi > + * Copyright (C) 2021 Charles Mirabile, Mwesigwa Guma, Joel Savitz > + * > + * Original Author: Serge Schneider > + * Revised for upstream Linux by: Charles Mirabile, Mwesigwa Guma, Joel Savitz > + */ > + > +#include <linux/module.h> > +#include <linux/input.h> > +#include <linux/i2c.h> > +#include <linux/interrupt.h> > +#include <linux/platform_device.h> > +#include <linux/regmap.h> > +#include <linux/of_irq.h> > +#include <linux/property.h> > + > +struct sensehat_joystick { > + struct platform_device *pdev; > + struct input_dev *keys_dev; > + unsigned long prev_states; > + u32 joystick_register; > +}; > + > +static const unsigned int keymap[] = { > + BTN_DPAD_DOWN, BTN_DPAD_RIGHT, BTN_DPAD_UP, BTN_SELECT, BTN_DPAD_LEFT, > +}; > + > +static irqreturn_t sensehat_joystick_report(int n, void *cookie) > +{ > + int i, error, keys; > + struct sensehat_joystick *sensehat_joystick = cookie; > + struct regmap *regmap = > + dev_get_regmap(sensehat_joystick->pdev->dev.parent, NULL); I think it's better to get this during probe and save it in 'struct sensehat_joystick'. You'll avoid having to search for it everytime. > + unsigned long curr_states, changes; > + > + error = regmap_read(regmap, sensehat_joystick->joystick_register, > + &keys); > + if (error < 0) { > + dev_err(&sensehat_joystick->pdev->dev, > + "Failed to read joystick state: %d", error); > + return IRQ_NONE; > + } > + curr_states = keys; > + bitmap_xor(&changes, &curr_states, &sensehat_joystick->prev_states, > + ARRAY_SIZE(keymap)); > + > + for_each_set_bit(i, &changes, ARRAY_SIZE(keymap)) { > + input_report_key(sensehat_joystick->keys_dev, keymap[i], > + curr_states & BIT(i)); > + } > + > + input_sync(sensehat_joystick->keys_dev); > + sensehat_joystick->prev_states = keys; > + return IRQ_HANDLED; > +} > + > +static int sensehat_joystick_probe(struct platform_device *pdev) > +{ > + int error, i; > + struct sensehat_joystick *sensehat_joystick = devm_kzalloc( > + &pdev->dev, sizeof(*sensehat_joystick), GFP_KERNEL); > + > + sensehat_joystick->pdev = pdev; > + sensehat_joystick->keys_dev = devm_input_allocate_device(&pdev->dev); > + if (!sensehat_joystick->keys_dev) { > + dev_err(&pdev->dev, "Could not allocate input device.\n"); > + return -ENOMEM; > + } > + > + for (i = 0; i < ARRAY_SIZE(keymap); i++) > + set_bit(keymap[i], sensehat_joystick->keys_dev->keybit); > + > + sensehat_joystick->keys_dev->name = "Raspberry Pi Sense HAT Joystick"; > + sensehat_joystick->keys_dev->phys = "sensehat-joystick/input0"; > + sensehat_joystick->keys_dev->id.bustype = BUS_I2C; > + sensehat_joystick->keys_dev->evbit[0] = > + BIT_MASK(EV_KEY) | BIT_MASK(EV_REP); > + > + error = input_register_device(sensehat_joystick->keys_dev); > + if (error) { > + dev_err(&pdev->dev, "Could not register input device.\n"); > + return error; > + } > + > + error = device_property_read_u32(&pdev->dev, "reg", > + &sensehat_joystick->joystick_register); > + if (error) { > + dev_err(&pdev->dev, "Could not read register property.\n"); > + return error; > + } I don't think you really need to pass this information through the devicetree. It's just the address to a register, not a HW design detail (i.e. how the board is layout). Using a define is good enough. > + > + error = devm_request_threaded_irq(&pdev->dev, > + of_irq_get(pdev->dev.of_node, 0), Use platform_get_irq() and remember the function may fail, both unrecoverable errors and EPROBE_DEFER when the irqchip isn't ready yet. > + NULL, sensehat_joystick_report, > + IRQF_ONESHOT, "keys", > + sensehat_joystick); > + > + if (error) { > + dev_err(&pdev->dev, "IRQ request failed.\n"); > + return error; > + } nit: space here > + return 0; > +} > + > +static const struct of_device_id sensehat_joystick_device_id[] = { > + { .compatible = "raspberrypi,sensehat-joystick" }, > + {}, > +}; > +MODULE_DEVICE_TABLE(of, sensehat_joystick_device_id); > + > +static struct platform_driver sensehat_joystick_driver = { > + .probe = sensehat_joystick_probe, > + .driver = { > + .name = "sensehat-joystick", > + .of_match_table = sensehat_joystick_device_id, > + }, > +}; > + > +module_platform_driver(sensehat_joystick_driver); > + > +MODULE_DESCRIPTION("Raspberry Pi Sense HAT joystick driver"); > +MODULE_AUTHOR("Serge Schneider <serge@xxxxxxxxxxxxxxx>"); > +MODULE_LICENSE("GPL"); -- Nicolás Sáenz
