ioc: Add basic structure

ioc/kernel-driver/.gitignore

@@ -0,0 +1,6 @@
+*.o
+*.ko
+*.mod.c
+modules.order
+Module.symvers
+*.pro.user

ioc/kernel-driver/Makefile

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+obj-m := lw35-ioc.o
+KDIR := ~/projects/arm-linux/current
+PWD := $(shell pwd)
+default: lw35-ioc.ko
+lw35-ioc.ko: lw35-ioc.c
+	$(MAKE) -C $(KDIR) SUBDIRS=$(PWD) modules
+
+deploy: lw35-ioc.ko
+	scp $< markus@opi:/home/markus/lw35-ioc/deploy
+
+clean:
+	rm -f ./*.o ./*.ko ./*.mod.c modules.order Module.symvers
+
+.phony: deploy clean

ioc/kernel-driver/device-tree-opi-pc.dtb

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+/*
+	Reading: https://www.kernel.org/doc/Documentation/devicetree/bindings/interrupt-controller/interrupts.txt
+*/
+
+&spi1 {
+	status = "okay";
+	lw35ioc@0 {
+		compatible = "brother,lw35ioc";
+		reg = <0x0>;
+		spi-max-frequency = <2000000>;
+		
+		pinctrl-names = "default";
+		pinctrl-0 = <&lw35ioc>;
+		data-gpios = <&pio 0 7 GPIO_ACTIVE_HIGH>; /* TODO: get real IO num */
+		
+		interrupt-parent = <&pio>;
+		interrupts = <52 2>;
+	};
+};
+
+&pio {
+	lmg6202ulyt_opc: lmg6202ulyt_pins {
+		pins = "PA7";
+		function = "gpio_out";
+		interrupt-controller;
+		#interrupt-cells = <1>;
+	};
+};

ioc/kernel-driver/lw35-ioc.c

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+#include <linux/init.h>
+#include <linux/dma-mapping.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/delay.h>
+#include <linux/spi/spi.h>
+#include <linux/of_device.h>
+#include <linux/gpio/consumer.h>
+#include <linux/interrupt.h>
+
+/*
+ * irq in general: https://notes.shichao.io/lkd/ch7/
+ * raspi irqs: http://morethanuser.blogspot.com/2013/04/raspberry-pi-gpio-interrupts-in-kernel.html
+ * kdoc devtree irq: https://www.kernel.org/doc/Documentation/devicetree/bindings/interrupt-controller/interrupts.txt
+ * GPIOD doc (including irq): https://www.kernel.org/doc/Documentation/gpio/consumer.txt
+ */
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Markus Koch");
+MODULE_DESCRIPTION("LW35 I/O Controller Driver");
+MODULE_VERSION("0.1");
+
+static char *testparam = "param";
+module_param(testparam, charp, S_IRUGO);
+MODULE_PARM_DESC(testparam, "A test parameter");
+
+static struct of_device_id lw35ioc_dt_ids[] = {
+{ .compatible = "brother,lw35", },
+{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, lw35ioc_dt_ids);
+
+struct lw35ioc_priv {
+	struct spi_device *spi;
+	
+	// USER VARS HERE
+};
+
+static int lw35ioc_probe(struct spi_device *spi)
+{
+	struct lw35ioc_priv *priv = NULL;
+
+	printk(KERN_INFO "lw35ioc: probe\n");
+
+	priv = devm_kzalloc(&spi->dev,
+			    sizeof(struct lw35ioc_priv),
+			    GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+	spi_set_drvdata(spi, priv);
+
+	priv->spi = spi;
+
+	printk(KERN_INFO "lw35ioc: Loaded driver\n");
+
+	return 0;
+
+	// Error handlers go here
+}
+
+static int lw35ioc_remove(struct spi_device *spi)
+{
+	struct lw35ioc_priv *priv = spi_get_drvdata(spi);
+
+	return 0;
+}
+
+static struct spi_driver lw35ioc_driver = {
+	.probe = lw35ioc_probe,
+	.remove = lw35ioc_remove,
+	.driver = {
+		.name = "lw35ioc",
+		.owner = THIS_MODULE,
+		.of_match_table = lw35ioc_dt_ids,
+	},
+};
+module_spi_driver(lw35ioc_driver);
+

ioc/kernel-driver/lw35-ioc.pro

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+TEMPLATE = app
+CONFIG += console
+CONFIG -= app_bundle
+CONFIG -= qt
+
+INCLUDEPATH += /home/markus/projects/arm-linux/current/include
+
+SOURCES += \
+        lw35-ioc.c