linux4microchip · kay54068 · Apr 10, 2025 · Apr 10, 2025 · May 12, 2022 · Apr 14, 2023
diff --git a/Documentation/devicetree/bindings/auxdisplay/raspberrypi,sensehat-display.yaml b/Documentation/devicetree/bindings/auxdisplay/raspberrypi,sensehat-display.yaml
@@ -0,0 +1,26 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/auxdisplay/raspberrypi,sensehat-display.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Raspberry Pi Sensehat Display
+
+maintainers:
+  - Charles Mirabile <[email protected]>
+  - Joel Savitz <[email protected]>
+
+description:
+  This device is part of the sensehat multi function device.
+  For more information see ../mfd/raspberrypi,sensehat.yaml.
+
+  This device features a programmable 8x8 RGB LED matrix.
+
+properties:
+  compatible:
+    const: raspberrypi,sensehat-display
+
+required:
+  - compatible
+
+additionalProperties: false
diff --git a/Documentation/devicetree/bindings/input/raspberrypi,sensehat-joystick.yaml b/Documentation/devicetree/bindings/input/raspberrypi,sensehat-joystick.yaml
@@ -0,0 +1,31 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/input/raspberrypi,sensehat-joystick.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Raspberry Pi Sensehat Joystick
+
+maintainers:
+  - Charles Mirabile <[email protected]>
+  - Joel Savitz <[email protected]>
+
+description:
+  This device is part of the sensehat multi function device.
+  For more information see ../mfd/raspberrypi,sensehat.yaml.
+
+  This device features a five button joystick (up, down,left,
+  right, click)
+
+properties:
+  compatible:
+    const: raspberrypi,sensehat-joystick
+
+  interrupts:
+    maxItems: 1
+
+required:
+  - compatible
+  - interrupts
+
+additionalProperties: false
diff --git a/Documentation/devicetree/bindings/mfd/raspberrypi,sensehat.yaml b/Documentation/devicetree/bindings/mfd/raspberrypi,sensehat.yaml
@@ -0,0 +1,57 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mfd/raspberrypi,sensehat.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Raspberry Pi Sensehat
+
+maintainers:
+  - Charles Mirabile <[email protected]>
+  - Joel Savitz <[email protected]>
+
+description:
+  The Raspberry Pi Sensehat is an addon board originally developed
+  for the Raspberry Pi that has a joystick and an 8x8 RGB LED display
+  as well as several environmental sensors. It connects via i2c and
+  a gpio for irq.
+
+properties:
+  compatible:
+    const: raspberrypi,sensehat
+
+  reg:
+    maxItems: 1
+
+  joystick:
+    $ref: /schemas/input/raspberrypi,sensehat-joystick.yaml#
+
+  display:
+    $ref: /schemas/auxdisplay/raspberrypi,sensehat-display.yaml#
+
+required:
+  - compatible
+  - reg
+  - joystick
+  - display
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+    i2c {
+      #address-cells = <1>;
+      #size-cells = <0>;
+      hat@46 {
+        compatible = "raspberrypi,sensehat";
+        reg = <0x46>;
+        display {
+          compatible = "raspberrypi,sensehat-display";
+        };
+        joystick {
+          compatible = "raspberrypi,sensehat-joystick";
+          interrupts = <23 IRQ_TYPE_EDGE_RISING>;
+        };
+      };
+    };
diff --git a/MAINTAINERS b/MAINTAINERS
@@ -20891,6 +20891,16 @@ F:	Documentation/ABI/testing/sysfs-bus-iio-chemical-sunrise-co2
 F:	Documentation/devicetree/bindings/iio/chemical/senseair,sunrise.yaml
 F:	drivers/iio/chemical/sunrise_co2.c
 
+SENSEHAT DRIVER
+M:	Charles Mirabile <[email protected]>
+M:	Joel Savitz <[email protected]>
+S:	Maintained
+F:	Documentation/devicetree/bindings/auxdisplay/raspberrypi,sensehat-display.yaml
+F:	Documentation/devicetree/bindings/input/raspberrypi,sensehat-joystick.yaml
+F:	Documentation/devicetree/bindings/mfd/raspberrypi,sensehat.yaml
+F:	drivers/auxdisplay/sensehat-display.c
+F:	drivers/input/joystick/sensehat-joystick.c
+
 SENSIRION SCD30 CARBON DIOXIDE SENSOR DRIVER
 M:	Tomasz Duszynski <[email protected]>
 S:	Maintained

diff --git a/drivers/auxdisplay/Kconfig b/drivers/auxdisplay/Kconfig
@@ -59,6 +59,14 @@ config LCD2S
 	  is a simple single color character display. You have to connect it
 	  to an I2C bus.
 
+config SENSEHAT_DISPLAY
+	tristate "Raspberry Pi Sense HAT display driver"
+	depends on I2C
+	select MFD_SIMPLE_MFD_I2C
+	help
+	 This is a driver for the Raspberry Pi Sensehat 8x8 RBG-LED matrix
+	 you can access it as a misc device at /dev/sense-hat
+
 menuconfig PARPORT_PANEL
 	tristate "Parallel port LCD/Keypad Panel support"
 	depends on PARPORT

diff --git a/drivers/auxdisplay/Makefile b/drivers/auxdisplay/Makefile
@@ -16,3 +16,4 @@ obj-$(CONFIG_LINEDISP)		+= line-display.o
 obj-$(CONFIG_MAX6959)		+= max6959.o
 obj-$(CONFIG_PARPORT_PANEL)	+= panel.o
 obj-$(CONFIG_SEG_LED_GPIO)	+= seg-led-gpio.o
+obj-$(CONFIG_SENSEHAT_DISPLAY)	+= sensehat-display.o
diff --git a/drivers/auxdisplay/sensehat-display.c b/drivers/auxdisplay/sensehat-display.c
@@ -0,0 +1,204 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Raspberry Pi Sense HAT 8x8 LED matrix display driver
+ * http://raspberrypi.org
+ *
+ * Copyright (C) 2015 Raspberry Pi
+ * Copyright (C) 2021 Charles Mirabile, Joel Savitz
+ *
+ * Original Author: Serge Schneider
+ * Revised for upstream Linux by: Charles Mirabile, Joel Savitz
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/mod_devicetable.h>
+#include <linux/miscdevice.h>
+#include <linux/regmap.h>
+#include <linux/property.h>
+
+#define DISPLAY_SMB_REG 0x00
+#define RGB_555_MASK 0x1f
+#define NUM_LEDS 8
+#define NUM_CHANNELS 3
+
+struct sensehat_display {
+	struct platform_device *pdev;
+	struct miscdevice mdev;
+	struct mutex rw_mtx;
+	u8 vmem[NUM_LEDS][NUM_LEDS][NUM_CHANNELS];
+	struct regmap *regmap;
+};
+
+#define VMEM_SIZE sizeof_field(struct sensehat_display, vmem)
+
+
+static int sensehat_update_display(struct sensehat_display *display)
+{
+	int i, j, k, ret;
+	u8 buff[NUM_LEDS][NUM_CHANNELS][NUM_LEDS];
+
+	for (i = 0; i < NUM_LEDS; ++i)
+		for (j = 0; j < NUM_LEDS; ++j)
+			for (k = 0; k < NUM_CHANNELS; ++k)
+				buff[i][k][j] =
+					display->vmem[i][j][k] & RGB_555_MASK;
+
+	ret = regmap_bulk_write(display->regmap, DISPLAY_SMB_REG, buff,
+				VMEM_SIZE);
+	if (ret < 0)
+		dev_err(&display->pdev->dev,
+			"Update to 8x8 LED matrix display failed");
+	return ret;
+}
+
+static loff_t sensehat_display_llseek(struct file *filp, loff_t offset,
+				      int whence)
+{
+	return fixed_size_llseek(filp, offset, whence, VMEM_SIZE);
+}
+
+static ssize_t sensehat_display_read(struct file *filp, char __user *buf,
+				     size_t count, loff_t *f_pos)
+{
+	struct sensehat_display *sensehat_display =
+		container_of(filp->private_data, struct sensehat_display, mdev);
+	ssize_t ret = -EFAULT;
+
+	if (*f_pos < 0 || *f_pos >= VMEM_SIZE)
+		return 0;
+	count = min_t(size_t, count, VMEM_SIZE - *f_pos);
+
+	if (mutex_lock_interruptible(&sensehat_display->rw_mtx))
+		return -ERESTARTSYS;
+	if (copy_to_user(buf, *f_pos + (u8 *)sensehat_display->vmem, count))
+		goto out;
+	*f_pos += count;
+	ret = count;
+out:
+	mutex_unlock(&sensehat_display->rw_mtx);
+	return ret;
+}
+
+static ssize_t sensehat_display_write(struct file *filp, const char __user *buf,
+				      size_t count, loff_t *f_pos)
+{
+	struct sensehat_display *sensehat_display =
+		container_of(filp->private_data, struct sensehat_display, mdev);
+	int ret = -EFAULT;
+
+	if (*f_pos < 0 || *f_pos >= VMEM_SIZE)
+		return -EFBIG;
+	count = min_t(size_t, count, VMEM_SIZE - *f_pos);
+
+	if (mutex_lock_interruptible(&sensehat_display->rw_mtx))
+		return -ERESTARTSYS;
+	if (copy_from_user(*f_pos + (u8 *)sensehat_display->vmem, buf, count))
+		goto out;
+	ret = sensehat_update_display(sensehat_display);
+	if (ret < 0) {
+		ret = -EIO;
+		goto out;
+	}
+	*f_pos += count;
+	ret = count;
+out:
+	mutex_unlock(&sensehat_display->rw_mtx);
+	return ret;
+}
+
+static const struct file_operations sensehat_display_fops = {
+	.owner = THIS_MODULE,
+	.llseek = sensehat_display_llseek,
+	.read = sensehat_display_read,
+	.write = sensehat_display_write,
+};
+
+static int sensehat_display_probe(struct platform_device *pdev)
+{
+	int ret;
+
+	struct sensehat_display *sensehat_display =
+		devm_kmalloc(&pdev->dev, sizeof(*sensehat_display), GFP_KERNEL);
+	if (!sensehat_display)
+		return -ENOMEM;
+
+	sensehat_display->pdev = pdev;
+
+	dev_set_drvdata(&pdev->dev, sensehat_display);
+
+	sensehat_display->regmap = dev_get_regmap(pdev->dev.parent, NULL);
+	if (!sensehat_display->regmap) {
+		dev_err(&pdev->dev,
+			"unable to get sensehat regmap");
+		return -ENODEV;
+	}
+
+	memset(sensehat_display->vmem, 0, VMEM_SIZE);
+
+	mutex_init(&sensehat_display->rw_mtx);
+
+	ret = sensehat_update_display(sensehat_display);
+	if (ret < 0) {
+		dev_err(&pdev->dev,
+			"Could not communicate with sensehat");
+		return ret;
+	}
+
+	sensehat_display->mdev = (struct miscdevice){
+		.minor = MISC_DYNAMIC_MINOR,
+		.name = "sense-hat",
+		.mode = 0666,
+		.fops = &sensehat_display_fops,
+	};
+
+	ret = misc_register(&sensehat_display->mdev);
+	if (ret < 0) {
+		dev_err(&pdev->dev,
+			"Could not register 8x8 LED matrix display.");
+		return ret;
+	}
+
+	dev_info(&pdev->dev,
+		 "8x8 LED matrix display registered with minor number %i",
+		 sensehat_display->mdev.minor);
+
+	return 0;
+}
+
+static void sensehat_display_remove(struct platform_device *pdev)
+{
+	struct sensehat_display *sensehat_display = dev_get_drvdata(&pdev->dev);
+
+	misc_deregister(&sensehat_display->mdev);
+}
+
+static const struct of_device_id sensehat_display_device_id[] = {
+	{ .compatible = "raspberrypi,sensehat-display" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, sensehat_display_device_id);
+
+static struct platform_driver sensehat_display_driver = {
+	.probe = sensehat_display_probe,
+	.remove = sensehat_display_remove,
+	.driver = {
+		.name = "sensehat-display",
+		.of_match_table = sensehat_display_device_id,
+	},
+};
+
+module_platform_driver(sensehat_display_driver);
+
+MODULE_DESCRIPTION("Raspberry Pi Sense HAT 8x8 LED matrix display driver");
+MODULE_AUTHOR("Charles Mirabile <[email protected]>");
+MODULE_AUTHOR("Serge Schneider <[email protected]>");
+MODULE_LICENSE("GPL");
diff --git a/drivers/mfd/simple-mfd-i2c.c b/drivers/mfd/simple-mfd-i2c.c
@@ -88,6 +88,7 @@ static const struct of_device_id simple_mfd_i2c_of_match[] = {
 	{ .compatible = "silergy,sy7636a", .data = &silergy_sy7636a},
 	{ .compatible = "maxim,max5970", .data = &maxim_max5970},
 	{ .compatible = "maxim,max5978", .data = &maxim_max5970},
+	{ .compatible = "raspberrypi,sensehat" },
 	{}
 };
 MODULE_DEVICE_TABLE(of, simple_mfd_i2c_of_match);