gryphon-led-module: added driver for RGB led

gryphon-led-module/Makefile

@@ -0,0 +1,62 @@
+# Copyright (c) 2017 Genexis B.V.
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# version 2 as published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+# 02110-1301 USA
+
+include $(TOPDIR)/rules.mk
+include $(INCLUDE_DIR)/kernel.mk
+
+PKG_NAME:=gryphon-led-kernel-module
+PKG_RELEASE:=1
+
+include $(INCLUDE_DIR)/package.mk
+
+define KernelPackage/$(PKG_NAME)
+  SUBMENU:=Genexis
+  TITLE:=LED driver for Gryphon
+  FILES:=$(PKG_BUILD_DIR)/$(PKG_NAME).$(LINUX_KMOD_SUFFIX)
+  KCONFIG:=CONFIG_PACKAGE_kmod-gryphon-led-kernel-module=y
+  AUTOLOAD:=$(call AutoLoad,60,$(PKG_NAME))
+  PKG_LICENSE:=Genexis
+  PKG_LICENSE_URL:=
+endef
+
+define KernelPackage/$(PKG_NAME)/description
+  This package contains the LED driver for Gryphon devices.
+endef
+
+EXTRA_KCONFIG:= CONFIG_RGB_LED=m
+
+MODULE_INCLUDE=-I$(PKG_BUILD_DIR)
+
+define Build/Prepare
+	mkdir -p $(PKG_BUILD_DIR)/kdevlinks/
+	$(CP) -s `pwd`/src/* $(PKG_BUILD_DIR)/kdevlinks/
+	$(CP) src/* $(PKG_BUILD_DIR)
+endef
+
+define Build/Compile
+	$(MAKE) -C "$(LINUX_DIR)" \
+		CROSS_COMPILE="$(TARGET_CROSS)" \
+		ARCH="$(LINUX_KARCH)" \
+		SUBDIRS="$(PKG_BUILD_DIR)" \
+		EXTRA_CFLAGS="-DKERNEL_MODULE $(BUILDFLAGS) -I$(LINUX_DIR)/include -include generated/autoconf.h $(MODULE_INCLUDE)" \
+		modules
+endef
+
+define Build/InstallDev
+	$(INSTALL_DIR) $(1)/usr/include
+endef
+
+$(eval $(call KernelPackage,$(PKG_NAME)))

gryphon-led-module/src/Makefile

@@ -0,0 +1,26 @@
+# Copyright (c) 2017 Genexis B.V.
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# version 2 as published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+# 02110-1301 USA
+
+MODULE_NAME  = gryphon-led-kernel-module
+
+obj-m  := $(MODULE_NAME).o
+
+GENEXIS_FILES= \
+	main.o \
+	sk9822.o \
+	sk9822_bitbang.o
+
+$(MODULE_NAME)-objs := $(GENEXIS_FILES)

gryphon-led-module/src/main.c

@@ -0,0 +1,255 @@
+/*
+ * Copyright (c) 2017 Genexis B.V.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ */
+
+#define DEBUG 1
+
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/printk.h>
+#include <linux/init.h>
+#include <linux/err.h>
+#include <linux/platform_device.h>
+#include <linux/gpio/consumer.h>
+#include <linux/of.h>
+#include <linux/version.h>
+
+#include "sk9822.h"
+
+#define DRIVER_NAME			"canyon_led"
+#define DRIVER_AUTHOR		"Genexis B.V."
+#define DRIVER_DESC			"Canyon LED driver for SK9822"
+#define DRIVER_VERSION	"1"
+
+/**
+ * sysfs interfaces
+ */
+
+static ssize_t get_led_color(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	/* [ln] todo: dummy implementation */
+	int len;
+
+	len = sprintf(buf, "%d\n", 123);
+	if (len <= 0) {
+		dev_err(dev, "sk9822: Invalid sprintf len: %d\n", len);
+	}
+
+	return len;
+}
+
+/**
+ * @brief Set complete LED strip to a specific color
+ * @retval count number of bytes written
+ * @retval -EMSGSIZE if the message is too big
+ * @retval -EIO for all other errors (e.g. leds cannot be configured)
+ */
+static ssize_t set_led_color(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t count)
+{
+	int ret = 0;
+	size_t buflen = count;
+	struct sk9822_leds *sk9822 = dev_get_drvdata(dev);
+
+	if (IS_ERR(sk9822)) {
+		printk(KERN_ERR "Platform get drvdata returned NULL\n");
+		return -EIO;
+	}
+
+	/* strip newline */
+	if ((count > 0) && (buf[count-1] == '\n')) {
+		buflen--;
+	}
+
+	if (buflen != 6) { // RRGGBB\0
+		return -EMSGSIZE;
+	}
+
+	// Update the LED array here
+	printk(KERN_DEBUG "Set LED color\n");
+	ret = sk9822_set_color_str(sk9822, buf);
+	if (ret != 0) {
+		printk(KERN_ERR "Failed to set led color\n");
+		return -EIO;
+	}
+
+	// Now push to the HW
+	ret = sk9822_update(sk9822);
+	if (ret != 0) {
+		printk(KERN_ERR "Failed to update led\n");
+		return -EIO;
+	}
+
+	return count;
+}
+static DEVICE_ATTR(led_color, S_IRUGO | S_IWUSR, get_led_color, set_led_color);
+
+static struct attribute *sk9822_dev_attrs[] = {
+	 &dev_attr_led_color.attr,
+	 NULL
+};
+
+static struct attribute_group sk9822_dev_attr_group = {
+	.name = "sk9822",
+	.attrs = sk9822_dev_attrs,
+};
+
+/**
+ * device prope and removal
+ */
+
+static int canyon_led_probe(struct platform_device *pdev)
+{
+	int ret;
+	struct sk9822_leds *leds;
+
+	printk(KERN_NOTICE "Begin probing...\n");
+
+	leds = devm_kzalloc(&pdev->dev, sizeof(*leds), GFP_KERNEL);
+	if (!leds) {
+		return -ENOMEM;
+	}
+	leds->dev = &pdev->dev;
+	leds->led_brightness = SK9822_DEFAULT_BRIGHTNESS;
+
+	leds->led_colors = devm_kzalloc(&pdev->dev,
+			(sizeof(cRGB) * leds->led_count), GFP_KERNEL);
+	if (!leds->led_colors) {
+		return -ENOMEM;
+	}
+
+	ret = of_property_read_u16(pdev->dev.of_node, "led-count", &leds->led_count);
+	if (ret < 0) {
+		dev_warn(&pdev->dev, "Could not read led-count property\n");
+		leds->led_count = SK9822_DEFAULT_NUM_LEDS;
+	}
+
+	platform_set_drvdata(pdev, leds);
+
+	printk(KERN_INFO "Allocated memory\n");
+
+#if LINUX_VERSION_CODE <= KERNEL_VERSION(3, 16, 0)
+	leds->clock_gpio = gpiod_get_index(&pdev->dev, "led", 0);
+#elif LINUX_VERSION_CODE >= KERNEL_VERSION(4, 3, 0)
+	leds->clock_gpio = gpiod_get_index(&pdev->dev, "led", 0, GPIOD_OUT_HIGH);
+#else
+	dev_warn(&pdev->dev, "Kernel version Not supported\n");
+	exit(1);
+#endif
+
+	gpiod_direction_output(leds->clock_gpio, 1);
+	if (IS_ERR(leds->clock_gpio)) {
+		dev_err(&pdev->dev, "Failed to acquire clock GPIO %ld\n",
+				PTR_ERR(leds->clock_gpio));
+		leds->clock_gpio = NULL;
+		return PTR_ERR(leds->clock_gpio);
+	} else {
+		printk(KERN_INFO "Got clock gpio\n");
+		gpiod_set_value(leds->clock_gpio, 0);
+	}
+
+#if LINUX_VERSION_CODE <= KERNEL_VERSION(3, 16, 0)
+	leds->data_gpio = gpiod_get_index(&pdev->dev, "led", 1);
+#elif LINUX_VERSION_CODE >= KERNEL_VERSION(4, 3, 0)
+	leds->data_gpio = gpiod_get_index(&pdev->dev, "led", 1, GPIOD_OUT_HIGH);
+#else
+	dev_warn(&pdev->dev, "Kernel version Not supported\n");
+	exit(1);
+#endif
+
+	gpiod_direction_output(leds->data_gpio, 1);
+	if (IS_ERR(leds->data_gpio)) {
+		dev_err(&pdev->dev, "Failed to acquire data GPIO %ld\n",
+				PTR_ERR(leds->data_gpio));
+		leds->data_gpio = NULL;
+		return PTR_ERR(leds->data_gpio);
+	} else {
+		printk(KERN_INFO "Got data gpio\n");
+		gpiod_set_value(leds->data_gpio, 0);
+	}
+
+	printk(KERN_INFO "Attempt to set filefs stuff\n");
+	ret = sysfs_create_group(&pdev->dev.kobj, &sk9822_dev_attr_group);
+	if (ret) {
+		dev_err(&pdev->dev, "sysfs creation failed\n");
+		return ret;
+	}
+
+	printk(KERN_INFO "Flash LEDs to verify they work\n");
+	sk9822_set_color_str(leds, "00FF00");
+	sk9822_update(leds);
+	msleep(200);
+	sk9822_set_color_str(leds, "000000");
+	sk9822_update(leds);
+
+	printk(KERN_NOTICE "We made it, carry on...\n");
+
+	return 0;
+}
+
+static int canyon_led_remove(struct platform_device *pdev)
+{
+	struct sk9822_leds *leds;
+
+	sysfs_remove_group(&pdev->dev.kobj, &sk9822_dev_attr_group);
+
+	leds = platform_get_drvdata(pdev);
+	if (IS_ERR(leds)) {
+		printk(KERN_ERR "Platform get drvdata returned NULL\n");
+		return -1;
+	}
+
+	if (leds->clock_gpio) {
+		gpiod_put(leds->clock_gpio);
+	}
+
+	if (leds->data_gpio) {
+		gpiod_put(leds->data_gpio);
+	}
+
+	printk(KERN_NOTICE "Bye, bye\n");
+
+	return 0;
+}
+
+/**
+ * platform driver metadata
+ */
+
+static const struct of_device_id canyon_led_of_ids[] = {
+	{ .compatible = "canyon,led" },
+	{ }
+};
+
+static struct platform_driver canyon_led = {
+	.probe = &canyon_led_probe,
+	.remove = &canyon_led_remove,
+	.driver = {
+		.name = DRIVER_NAME,
+		.owner = THIS_MODULE,
+		.of_match_table = canyon_led_of_ids,
+	},
+};
+
+MODULE_DEVICE_TABLE(of, canyon_led_of_ids);
+module_platform_driver(canyon_led);
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_VERSION(DRIVER_VERSION);
+MODULE_LICENSE("GPL");

gryphon-led-module/src/sk9822.c

@@ -0,0 +1,86 @@
+/*
+ * Copyright (c) 2017 Genexis B.V.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ */
+
+#include <linux/kernel.h>
+#include <linux/types.h>
+
+#include "sk9822.h"
+#include "sk9822_bitbang.h"
+
+cRGB __hexs_to_rgb(const char *hex)
+{
+	cRGB rgb;
+	int r, g, b;
+
+	sscanf(hex, "%02x%02x%02x", &r, &g, &b);
+	// This needs sanity checking
+	rgb.r = r;
+	rgb.g = g;
+	rgb.b = b;
+	return rgb;
+}
+
+/**
+ * @brief update the color over the given device struct to the provided HEX color
+ */
+int sk9822_set_color_str(struct sk9822_leds *sk9822, const char *hex)
+{
+	int i;
+	cRGB color = __hexs_to_rgb(hex);
+
+	for (i = 0; i < sk9822->led_count; i++) {
+		sk9822->led_colors[i] = color;
+	}
+
+	return 0;
+}
+
+/**
+ * @brief write device struct to the device
+ */
+int sk9822_update(struct sk9822_leds *sk9822)
+{
+	uint16_t i;
+	uint8_t *rawarray = (uint8_t *)sk9822->led_colors;
+	uint16_t led_count = sk9822->led_count;
+
+	sk9822_bb_write(sk9822, 0x00);  // Start Frame
+	sk9822_bb_write(sk9822, 0x00);
+	sk9822_bb_write(sk9822, 0x00);
+	sk9822_bb_write(sk9822, 0x00);
+
+	for (i = 0; i < (led_count*3); i += 3) {
+		sk9822_bb_write(sk9822, 0xe0+sk9822->led_brightness);  // Maximum global brightness
+		sk9822_bb_write(sk9822, rawarray[i+0]);
+		sk9822_bb_write(sk9822, rawarray[i+1]);
+		sk9822_bb_write(sk9822, rawarray[i+2]);
+	}
+
+	// Reset frame - Only needed for SK9822, has no effect on APA102
+	sk9822_bb_write(sk9822, 0x00);
+	sk9822_bb_write(sk9822, 0x00);
+	sk9822_bb_write(sk9822, 0x00);
+	sk9822_bb_write(sk9822, 0x00);
+
+	// End frame: 8+8*(leds >> 4) clock cycles
+	for (i = 0; i < led_count; i += 16) {
+		sk9822_bb_write(sk9822, 0xff);  // 8 more clock cycles
+	}
+
+	return 0;
+}

gryphon-led-module/src/sk9822.h

@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2017 Genexis B.V.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ */
+
+#ifndef SK9822_H_
+#define SK9822_H_
+
+#include <linux/types.h>
+
+#define SK9822_DEFAULT_NUM_LEDS 32 // U16, used if DT param fails
+#define SK9822_DEFAULT_BRIGHTNESS 31  // 5-bit brightness, 0-31
+
+typedef struct {
+	uint8_t b;
+	uint8_t g;
+	uint8_t r;
+} cRGB;   // BGR (SK9822 Standard)
+
+struct sk9822_leds {
+	struct device *dev;
+	struct gpio_desc *clock_gpio;
+	struct gpio_desc *data_gpio;
+
+	cRGB *led_colors;
+	uint8_t led_brightness;
+	uint16_t led_count;
+};
+
+int sk9822_set_color_str(struct sk9822_leds *sk9822, const char *hex);
+int sk9822_update(struct sk9822_leds *sk9822);
+
+#endif /* SK9822_H_ */

gryphon-led-module/src/sk9822_bitbang.c

@@ -0,0 +1,48 @@
+/*
+ * Copyright (c) 2017 Genexis B.V.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ */
+
+#include <linux/gpio/consumer.h>
+#include <linux/delay.h>
+#include <linux/types.h>
+
+#include "sk9822.h"
+
+/**
+ * @brief Bitbang write operation CLOCK+DATA
+ *
+ * Assumed state before call: CLOCK- Low, DATA- High
+ */
+void sk9822_bb_write(struct sk9822_leds *sk9822, uint8_t c)
+{
+	uint8_t i;
+
+	for (i = 0; i < 8 ; i++) {
+		if (!(c&0x80)) {
+			gpiod_set_value(sk9822->data_gpio, 0); // set data low
+		} else {
+			gpiod_set_value(sk9822->data_gpio, 1); // set data high
+		}
+
+		gpiod_set_value(sk9822->clock_gpio, 1); // set clock high, data sampled here
+		c <<= 1;
+		udelay(1); // stretch clock
+		gpiod_set_value(sk9822->clock_gpio, 0); // set clock low
+	}
+
+	// State after call: SCK Low, Data high
+}

gryphon-led-module/src/sk9822_bitbang.h

@@ -0,0 +1,28 @@
+/*
+ * Copyright (c) 2017 Genexis B.V.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ */
+
+#ifndef _SK9822_BB_H_
+#define _SK9822_BB_H_
+
+#include <linux/types.h>
+
+#include "sk9822.h"
+
+void sk9822_bb_write(struct sk9822_leds *sk9822, uint8_t c);
+
+#endif /* _SK9822_BB_H_ */