[PATCH 2/5] drivers/input/joystick: sensehat: Raspberry Pi Sense HAT joystick driver

Charles Mirabile
2021-10-29T21:54:44Z

This patch implements support for the joystick.
It supports left/right/up/down/enter and is
attached via i2c and a gpio pin for irq.

Signed-off-by: Charles Mirabile <cmirabil@redhat.com>
Signed-off-by: Mwesigwa Guma <mguma@redhat.com>
Signed-off-by: Joel Savitz <jsavitz@redhat.com>
---
drivers/input/joystick/Kconfig | 8 ++
drivers/input/joystick/Makefile | 1 +
drivers/input/joystick/sensehat-joystick.c | 135 +++++++++++++++++++++
3 files changed, 144 insertions(+)
create mode 100644 drivers/input/joystick/sensehat-joystick.c

diff --git a/drivers/input/joystick/Kconfig b/drivers/input/joystick/Kconfig
index 3b23078bc7b5..d2f78353b74c 100644
--- a/drivers/input/joystick/Kconfig
+++ b/drivers/input/joystick/Kconfig
@@ -399,4 +399,12 @@ 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 GPIOLIB && INPUT
+ select MFD_SENSEHAT_CORE
+
+ help
+ This is the joystick driver for the Raspberry Pi Sense HAT
+
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..2a25287b5863
--- /dev/null
+++ b/drivers/input/joystick/sensehat-joystick.c
@@ -0,0 +1,135 @@
+// 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/gpio/consumer.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+#include "sensehat.h"
+
+int sensehat_get_joystick_state(struct sensehat *sensehat);
+
+static unsigned char keymap[] = {KEY_DOWN, KEY_RIGHT, KEY_UP, KEY_ENTER, KEY_LEFT,};
+
+static irqreturn_t sensehat_joystick_report(int n, void *cookie)
+{
+ int i;
+ static s32 prev_keys;
+ struct sensehat *sensehat = cookie;
+ struct sensehat_joystick *sensehat_joystick = &sensehat->joystick;
+ s32 keys = sensehat_get_joystick_state(sensehat);
+ s32 changes = keys ^ prev_keys;
+
+ prev_keys = keys;
+ for (i = 0; i < ARRAY_SIZE(keymap); ++i) {
+ if (changes & (1<<i)) {
+ input_report_key(sensehat_joystick->keys_dev,
+ keymap[i], keys & (1<<i));
+ }
+ }
+ input_sync(sensehat_joystick->keys_dev);
+ return IRQ_HANDLED;
+}
+
+static int sensehat_joystick_probe(struct platform_device *pdev)
+{
+ int ret;
+ int i;
+ struct sensehat *sensehat = dev_get_drvdata(&pdev->dev);
+ struct sensehat_joystick *sensehat_joystick = &sensehat->joystick;
+
+ sensehat_joystick->keys_desc = devm_gpiod_get(&sensehat->i2c_client->dev,
+ "keys-int", GPIOD_IN);
+ if (IS_ERR(sensehat_joystick->keys_desc)) {
+ dev_warn(&pdev->dev, "Failed to get keys-int descriptor.\n");
+ return PTR_ERR(sensehat_joystick->keys_desc);
+ }
+
+
+ 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 = "rpi-sense-joy/input0";
+ sensehat_joystick->keys_dev->id.bustype = BUS_I2C;
+ sensehat_joystick->keys_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REP);
+ sensehat_joystick->keys_dev->keycode = keymap;
+ sensehat_joystick->keys_dev->keycodesize = sizeof(unsigned char);
+ sensehat_joystick->keys_dev->keycodemax = ARRAY_SIZE(keymap);
+
+ ret = input_register_device(sensehat_joystick->keys_dev);
+ if (ret) {
+ dev_err(&pdev->dev, "Could not register input device.\n");
+ return ret;
+ }
+
+ ret = gpiod_direction_input(sensehat_joystick->keys_desc);
+ if (ret) {
+ dev_err(&pdev->dev, "Could not set keys-int direction.\n");
+ return ret;
+ }
+
+ sensehat_joystick->keys_irq = gpiod_to_irq(sensehat_joystick->keys_desc);
+ if (sensehat_joystick->keys_irq < 0) {
+ dev_err(&pdev->dev, "Could not determine keys-int IRQ.\n");
+ return sensehat_joystick->keys_irq;
+ }
+
+ ret = devm_request_threaded_irq(&pdev->dev, sensehat_joystick->keys_irq,
+ NULL, sensehat_joystick_report, IRQF_TRIGGER_RISING | IRQF_ONESHOT,
+ "keys", sensehat);
+
+ if (ret) {
+ dev_err(&pdev->dev, "IRQ request failed.\n");
+ return ret;
+ }
+ return 0;
+}
+
+int sensehat_get_joystick_state(struct sensehat *sensehat)
+{
+ unsigned int reg;
+ int ret = regmap_read(sensehat->regmap, SENSEHAT_KEYS, &reg);
+
+ return ret < 0 ? ret : reg;
+}
+
+static struct platform_device_id sensehat_joystick_device_id[] = {
+ { .name = "sensehat-joystick" },
+ { },
+};
+MODULE_DEVICE_TABLE(platform, sensehat_joystick_device_id);
+
+static struct platform_driver sensehat_joystick_driver = {
+ .probe = sensehat_joystick_probe,
+ .driver = {
+ .name = "sensehat-joystick",
+ },
+};
+
+module_platform_driver(sensehat_joystick_driver);
+
+MODULE_DESCRIPTION("Raspberry Pi Sense HAT joystick driver");
+MODULE_AUTHOR("Serge Schneider <serge@raspberrypi.org>");
+MODULE_LICENSE("GPL");
--
2.31.1