[dev] Add simple multi-instance device driver model.

Model supports class drivers capable of driving multiple device
instances independently. Implements simple pattern for device life
cycle management. Completely optional and self-contained.

dev/driver.c

@@ -0,0 +1,132 @@
+/*
+ * Copyright (c) 2012 Corey Tabaka
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files
+ * (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge,
+ * publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include <dev/driver.h>
+#include <assert.h>
+#include <err.h>
+
+extern struct device __devices[];
+extern struct device __devices_end[];
+
+status_t device_init_all(void)
+{
+	status_t res = NO_ERROR;
+
+	struct device *dev = __devices;
+	while (dev != __devices_end) {
+		status_t code = device_init(dev);
+
+		if (code < 0) {
+			TRACEF("Driver init failed for driver \"%s\", device \"%s\", reason %d\n",
+					dev->driver->type, dev->name, code);
+
+			res = code;
+		}
+
+		dev++;
+	}
+
+	return res;
+}
+
+status_t device_fini_all(void)
+{
+	status_t res = NO_ERROR;
+
+	struct device *dev = __devices;
+	while (dev != __devices_end) {
+		status_t code = device_fini(dev);
+
+		if (code < 0) {
+			TRACEF("Driver fini failed for driver \"%s\", device \"%s\", reason %d\n",
+					dev->driver->type, dev->name, code);
+
+			res = code;
+		}
+
+		dev++;
+	}
+
+	return res;
+}
+
+status_t device_init(struct device *dev)
+{
+	if (!dev)
+		return ERR_INVALID_ARGS;
+
+	DEBUG_ASSERT(dev->driver);
+	
+	const struct driver_ops *ops = dev->driver->ops;
+
+	if (ops && ops->init)
+		return ops->init(dev);
+	else
+		return ERR_NOT_SUPPORTED;
+}
+
+status_t device_fini(struct device *dev)
+{
+	if (!dev)
+		return ERR_INVALID_ARGS;
+	
+	DEBUG_ASSERT(dev->driver);
+
+	const struct driver_ops *ops = dev->driver->ops;
+
+	if (ops && ops->fini)
+		return ops->fini(dev);
+	else
+		return ERR_NOT_SUPPORTED;
+}
+
+status_t device_suspend(struct device *dev)
+{
+	if (!dev)
+		return ERR_NOT_SUPPORTED;
+	
+	DEBUG_ASSERT(dev->driver);
+
+	const struct driver_ops *ops = dev->driver->ops;
+
+	if (ops && ops->suspend)
+		return ops->suspend(dev);
+	else
+		return ERR_NOT_SUPPORTED;
+}
+
+status_t device_resume(struct device *dev)
+{
+	if (!dev)
+		return ERR_NOT_SUPPORTED;
+	
+	DEBUG_ASSERT(dev->driver);
+
+	const struct driver_ops *ops = dev->driver->ops;
+
+	if (ops && ops->resume)
+		return ops->resume(dev);
+	else
+		return ERR_NOT_SUPPORTED;
+}
+

dev/rules.mk

@@ -3,6 +3,7 @@ LOCAL_DIR := $(GET_LOCAL_DIR)
 MODULE := $(LOCAL_DIR)
 
 MODULE_SRCS += \
-	$(LOCAL_DIR)/dev.c
+	$(LOCAL_DIR)/dev.c \
+	$(LOCAL_DIR)/driver.c \
 
 include make/module.mk

include/compiler.h

@@ -151,6 +151,10 @@
 /* TODO: add type check */
 #define countof(a) (sizeof(a) / sizeof((a)[0]))
 
+/* macro-expanding concat */
+#define concat(a, b) __ex_concat(a, b)
+#define __ex_concat(a, b) a ## b
+
 /* CPP header guards */
 #ifdef __cplusplus
 #define __BEGIN_CDECLS  extern "C" {

include/dev/driver.h

@@ -0,0 +1,113 @@
+/*
+ * Copyright (c) 2012 Corey Tabaka
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files
+ * (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge,
+ * publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+#ifndef __DEV_DRIVER_H
+#define __DEV_DRIVER_H
+
+#include <sys/types.h>
+#include <list.h> // for containerof
+#include <compiler.h>
+
+struct driver;
+
+/*
+ * Contains the data pertaining to an instance of a device. More than one
+ * instance may exist for a given driver type (i.e. uart0, uart1, etc..).
+ */
+struct device {
+	const char *name;
+	const struct driver *driver;
+
+	/* instance specific config data populated at instantiation */
+	const void *config;
+
+	/* instance specific data populated by the driver at init */
+	void *state;
+	
+	// TODO: add generic state, such as suspend/resume state, etc...
+};
+
+/* device class, mainly used as a unique magic pointer to validate ops */
+struct device_class {
+	const char *name;
+};
+
+/* standard driver ops; extensions should contain this ops structure */
+struct driver_ops {
+	const struct device_class *device_class;
+
+	status_t (*init)(struct device *dev);
+	status_t (*fini)(struct device *dev);
+
+	status_t (*suspend)(struct device *dev);
+	status_t (*resume)(struct device *dev);
+};
+
+/* describes a driver, one per driver type */
+struct driver {
+	const char *type;
+	const struct driver_ops *ops;
+};
+
+#define DRIVER_EXPORT(type_, ops_) \
+	struct driver concat(__driver_, type_) \
+		__SECTION(".drivers") = { \
+		.type = #type_, \
+		.ops = ops_, \
+	}
+
+#define DEVICE_INSTANCE(type_, name_, config_) \
+	extern struct driver concat(__driver_, type_); \
+	struct device concat(__device_, concat(type_, concat(_, name_))) \
+		__SECTION(".devices") = { \
+		.name = #name_, \
+		.driver = &concat(__driver_, type_), \
+		.config = config_, \
+	}
+
+/*
+ * returns the driver specific ops pointer given the device instance, specifc
+ * ops type, and generic ops member name within the specific ops structure.
+ */
+#define device_get_driver_ops(dev, type, member) ({ \
+	type *__ops = NULL; \
+	if (dev && dev->driver && dev->driver->ops) \
+		__ops = containerof(dev->driver->ops, type, member); \
+	__ops; \
+})
+
+#define device_get_by_name(type_, name_) ({ \
+	extern struct device concat(__device_, concat(type_, concat(_, name_))); \
+	&concat(__device_, concat(type_, concat(_, name_))); \
+})
+
+status_t device_init_all(void);
+status_t device_fini_all(void);
+
+status_t device_init(struct device *dev);
+status_t device_fini(struct device *dev);
+
+status_t device_suspend(struct device *dev);
+status_t device_resume(struct device *dev);
+
+#endif
+

include/err.h

@@ -52,5 +52,6 @@
 #define ERR_NOT_SUPPORTED -24
 #define ERR_TOO_BIG -25
 #define ERR_THREAD_DETACHED -26
+#define ERR_NOT_CONFIGURED -27
 
 #endif