drivers/ws281x: Add saul support

drivers/saul/init_devs/auto_init_ws281x.c

@@ -0,0 +1,71 @@
+/*
+ * Copyright (C) 2024 HAW Hamburg
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License v2.1. See the file LICENSE in the top level
+ * directory for more details.
+ *
+ */
+
+/**
+ * @ingroup     sys_auto_init_saul
+ * @{
+ *
+ * @file
+ * @brief       Auto initialization of ws281x RGB LED devices
+ *
+ * @author      Kevin Weiss <kevin.weiss@haw-hamburg.de>
+ *
+ * @}
+ */
+
+#include "assert.h"
+#include "log.h"
+#include "saul_reg.h"
+
+#include "ws281x.h"
+#include "ws281x_params.h"
+
+/**
+ * @brief   Define the number of configured sensors
+ */
+#define WS281X_NUM     ARRAY_SIZE(ws281x_params)
+
+/**
+ * @brief   Allocate memory for the device descriptors
+ */
+static ws281x_t ws281x_devs[WS281X_NUM];
+
+/**
+ * @brief   Memory for the SAUL registry entries
+ */
+static saul_reg_t saul_entries[WS281X_NUM];
+
+/**
+ * @brief   Define the number of saul info
+ */
+#define WS281X_INFO_NUM ARRAY_SIZE(ws281x_saul_info)
+
+/**
+ * @brief   Reference the driver struct
+ */
+extern const saul_driver_t ws281x_saul_driver;
+
+void auto_init_ws281x(void)
+{
+    assert(WS281X_NUM == WS281X_INFO_NUM);
+
+    for (unsigned i = 0; i < WS281X_NUM; i++) {
+        LOG_DEBUG("[auto_init_saul] initializing WS281x #%u: ", i);
+
+        if (ws281x_init(&ws281x_devs[i], &ws281x_params[i]) != 0) {
+            LOG_ERROR("ERROR\n");
+            continue;
+        }
+        LOG_DEBUG("SUCCESS\n");
+        saul_entries[i].dev = &(ws281x_devs[i]);
+        saul_entries[i].name = ws281x_saul_info[i].name;
+        saul_entries[i].driver = &ws281x_saul_driver;
+        saul_reg_add(&(saul_entries[i]));
+    }
+}

drivers/saul/init_devs/init.c

@@ -343,4 +343,8 @@ void saul_init_devs(void)
         extern void auto_init_servo(void);
         auto_init_servo();
     }
+    if (IS_USED(MODULE_WS281X)) {
+        extern void auto_init_ws281x(void);
+        auto_init_ws281x();
+    }
 }

drivers/ws281x/Makefile

@@ -1,3 +1,14 @@
 SRC := ws281x.c # All other sources files provide ws281x_write as submodule
 SUBMODULES := 1
+
+# Since we have submodules we need to manually handle saul instead of
+# including driver_with_saul.mk
+MODULE ?= $(shell basename $(CURDIR))
+SAUL_INTERFACE ?= $(MODULE)_saul.c
+
+# only include <module>_saul.c if saul module is used
+ifneq (,$(filter saul,$(USEMODULE)))
+  SRC += $(SAUL_INTERFACE)
+endif
+
 include $(RIOTBASE)/Makefile.base

drivers/ws281x/Makefile.dep

@@ -37,3 +37,6 @@ endif
 ifneq (,$(filter ws281x_timer_gpio_ll,$(USEMODULE)))
   FEATURES_REQUIRED += periph_gpio_ll periph_timer periph_timer_poll
 endif
+
+# It would seem xtimer is always required as it is used in the header...
+USEMODULE += xtimer

drivers/ws281x/include/ws281x_params.h

@@ -20,6 +20,8 @@
 #define WS281X_PARAMS_H
 
 #include "board.h"
+#include "saul_reg.h"
+
 #include "ws281x.h"
 
 #ifdef __cplusplus
@@ -105,6 +107,21 @@ static const ws281x_params_t ws281x_params[] =
 #define WS281X_TIMER_FREQ 16000000
 #endif
 
+/**
+ * @brief   SAUL info
+ */
+#ifndef WS281X_SAUL_INFO
+#define WS281X_SAUL_INFO  { .name = "WS281X RGB LED" }
+#endif
+
+/**
+ * @brief   Additional meta information to keep in the SAUL registry
+ */
+static const saul_reg_info_t ws281x_saul_info[] =
+{
+    WS281X_SAUL_INFO
+};
+
 #ifdef __cplusplus
 }
 #endif

drivers/ws281x/ws281x_saul.c

@@ -0,0 +1,47 @@
+/*
+ * Copyright (C) 2024 HAW Hamburg
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License v2.1. See the file LICENSE in the top level
+ * directory for more details.
+ */
+
+/**
+ * @ingroup     drivers_ws281x
+ * @{
+ *
+ * @file
+ * @brief       NEOPixel/ws281x adaption to SAUL
+ *
+ * @author      Kevin Weiss <kevin.weiss@haw-hamburg.de>
+ *
+ * @}
+ */
+
+#include <string.h>
+#include <stdio.h>
+
+#include "saul.h"
+#include "ws281x.h"
+
+static int set_rgb_led(const void *dev, const phydat_t *res)
+{
+    ws281x_t *ws281x = (ws281x_t *)dev;
+    color_rgb_t color = {
+        .r = res->val[0],
+        .g = res->val[1],
+        .b = res->val[2]
+    };
+    for (unsigned idx = 0; idx < ws281x->params.numof; idx++) {
+        puts("Setting LED");
+        ws281x_set(ws281x, idx, color);
+    }
+    ws281x_write(ws281x);
+    return 1;
+}
+
+const saul_driver_t ws281x_saul_driver = {
+    .read = saul_read_notsup,
+    .write = set_rgb_led,
+    .type = SAUL_ACT_LED_RGB,
+};