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alistair23-linux/include/linux/platform_device.h
Paul Gortmaker f309d44431 platform_device: better support builtin boilerplate avoidance 
We have macros that help reduce the boilerplate for modules
that register with no extra init/exit complexity other than the
most standard use case.  However we see an increasing number of
non-modular drivers using these modular_driver() type register
functions.

There are several downsides to this:
1) The code can appear modular to a reader of the code, and they
   won't know if the code really is modular without checking the
   Makefile and Kconfig to see if compilation is governed by a
   bool or tristate.
2) Coders of drivers may be tempted to code up an __exit function
   that is never used, just in order to satisfy the required three
   args of the modular registration function.
3) Non-modular code ends up including the <module.h> which increases
   CPP overhead that they don't need.
4) It hinders us from performing better separation of the module
   init code and the generic init code.

Here we introduce similar macros, with the mapping from module_driver
to builtin_driver and similar, so that simple changes of:

  module_platform_driver()       --->  builtin_platform_driver()
  module_platform_driver_probe() --->  builtin_platform_driver_probe().

can help us avoid #3 above, without having to code up the same
__init functions and device_initcall() boilerplate.

For non modular code, module_init becomes __initcall.  But direct use
of __initcall is discouraged, vs. one of the priority categorized
subgroups.  As __initcall gets mapped onto device_initcall, our
use of device_initcall directly in this change means that the
runtime impact is zero -- drivers will remain at level 6 in the
initcall ordering.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2015-06-16 14:12:37 -04:00

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/*
* platform_device.h - generic, centralized driver model
*
* Copyright (c) 2001-2003 Patrick Mochel <mochel@osdl.org>
*
* This file is released under the GPLv2
*
* See Documentation/driver-model/ for more information.
*/
#ifndef _PLATFORM_DEVICE_H_
#define _PLATFORM_DEVICE_H_
#include <linux/device.h>
#include <linux/mod_devicetable.h>
#define PLATFORM_DEVID_NONE (-1)
#define PLATFORM_DEVID_AUTO (-2)
struct mfd_cell;
struct platform_device {
const char *name;
int id;
bool id_auto;
struct device dev;
u32 num_resources;
struct resource *resource;
const struct platform_device_id *id_entry;
char *driver_override; /* Driver name to force a match */
/* MFD cell pointer */
struct mfd_cell *mfd_cell;
/* arch specific additions */
struct pdev_archdata archdata;
};
#define platform_get_device_id(pdev) ((pdev)->id_entry)
#define to_platform_device(x) container_of((x), struct platform_device, dev)
extern int platform_device_register(struct platform_device *);
extern void platform_device_unregister(struct platform_device *);
extern struct bus_type platform_bus_type;
extern struct device platform_bus;
extern void arch_setup_pdev_archdata(struct platform_device *);
extern struct resource *platform_get_resource(struct platform_device *,
unsigned int, unsigned int);
extern int platform_get_irq(struct platform_device *, unsigned int);
extern struct resource *platform_get_resource_byname(struct platform_device *,
unsigned int,
const char *);
extern int platform_get_irq_byname(struct platform_device *, const char *);
extern int platform_add_devices(struct platform_device **, int);
struct platform_device_info {
struct device *parent;
struct fwnode_handle *fwnode;
const char *name;
int id;
const struct resource *res;
unsigned int num_res;
const void *data;
size_t size_data;
u64 dma_mask;
};
extern struct platform_device *platform_device_register_full(
const struct platform_device_info *pdevinfo);
/**
* platform_device_register_resndata - add a platform-level device with
* resources and platform-specific data
*
* @parent: parent device for the device we're adding
* @name: base name of the device we're adding
* @id: instance id
* @res: set of resources that needs to be allocated for the device
* @num: number of resources
* @data: platform specific data for this platform device
* @size: size of platform specific data
*
* Returns &struct platform_device pointer on success, or ERR_PTR() on error.
*/
static inline struct platform_device *platform_device_register_resndata(
struct device *parent, const char *name, int id,
const struct resource *res, unsigned int num,
const void *data, size_t size) {
struct platform_device_info pdevinfo = {
.parent = parent,
.name = name,
.id = id,
.res = res,
.num_res = num,
.data = data,
.size_data = size,
.dma_mask = 0,
};
return platform_device_register_full(&pdevinfo);
}
/**
* platform_device_register_simple - add a platform-level device and its resources
* @name: base name of the device we're adding
* @id: instance id
* @res: set of resources that needs to be allocated for the device
* @num: number of resources
*
* This function creates a simple platform device that requires minimal
* resource and memory management. Canned release function freeing memory
* allocated for the device allows drivers using such devices to be
* unloaded without waiting for the last reference to the device to be
* dropped.
*
* This interface is primarily intended for use with legacy drivers which
* probe hardware directly. Because such drivers create sysfs device nodes
* themselves, rather than letting system infrastructure handle such device
* enumeration tasks, they don't fully conform to the Linux driver model.
* In particular, when such drivers are built as modules, they can't be
* "hotplugged".
*
* Returns &struct platform_device pointer on success, or ERR_PTR() on error.
*/
static inline struct platform_device *platform_device_register_simple(
const char *name, int id,
const struct resource *res, unsigned int num)
{
return platform_device_register_resndata(NULL, name, id,
res, num, NULL, 0);
}
/**
* platform_device_register_data - add a platform-level device with platform-specific data
* @parent: parent device for the device we're adding
* @name: base name of the device we're adding
* @id: instance id
* @data: platform specific data for this platform device
* @size: size of platform specific data
*
* This function creates a simple platform device that requires minimal
* resource and memory management. Canned release function freeing memory
* allocated for the device allows drivers using such devices to be
* unloaded without waiting for the last reference to the device to be
* dropped.
*
* Returns &struct platform_device pointer on success, or ERR_PTR() on error.
*/
static inline struct platform_device *platform_device_register_data(
struct device *parent, const char *name, int id,
const void *data, size_t size)
{
return platform_device_register_resndata(parent, name, id,
NULL, 0, data, size);
}
extern struct platform_device *platform_device_alloc(const char *name, int id);
extern int platform_device_add_resources(struct platform_device *pdev,
const struct resource *res,
unsigned int num);
extern int platform_device_add_data(struct platform_device *pdev,
const void *data, size_t size);
extern int platform_device_add(struct platform_device *pdev);
extern void platform_device_del(struct platform_device *pdev);
extern void platform_device_put(struct platform_device *pdev);
struct platform_driver {
int (*probe)(struct platform_device *);
int (*remove)(struct platform_device *);
void (*shutdown)(struct platform_device *);
int (*suspend)(struct platform_device *, pm_message_t state);
int (*resume)(struct platform_device *);
struct device_driver driver;
const struct platform_device_id *id_table;
bool prevent_deferred_probe;
};
#define to_platform_driver(drv) (container_of((drv), struct platform_driver, \
driver))
/*
* use a macro to avoid include chaining to get THIS_MODULE
*/
#define platform_driver_register(drv) \
__platform_driver_register(drv, THIS_MODULE)
extern int __platform_driver_register(struct platform_driver *,
struct module *);
extern void platform_driver_unregister(struct platform_driver *);
/* non-hotpluggable platform devices may use this so that probe() and
* its support may live in __init sections, conserving runtime memory.
*/
#define platform_driver_probe(drv, probe) \
__platform_driver_probe(drv, probe, THIS_MODULE)
extern int __platform_driver_probe(struct platform_driver *driver,
int (*probe)(struct platform_device *), struct module *module);
static inline void *platform_get_drvdata(const struct platform_device *pdev)
{
return dev_get_drvdata(&pdev->dev);
}
static inline void platform_set_drvdata(struct platform_device *pdev,
void *data)
{
dev_set_drvdata(&pdev->dev, data);
}
/* module_platform_driver() - Helper macro for drivers that don't do
* anything special in module init/exit. This eliminates a lot of
* boilerplate. Each module may only use this macro once, and
* calling it replaces module_init() and module_exit()
*/
#define module_platform_driver(__platform_driver) \
module_driver(__platform_driver, platform_driver_register, \
platform_driver_unregister)
/* builtin_platform_driver() - Helper macro for builtin drivers that
* don't do anything special in driver init. This eliminates some
* boilerplate. Each driver may only use this macro once, and
* calling it replaces device_initcall(). Note this is meant to be
* a parallel of module_platform_driver() above, but w/o _exit stuff.
*/
#define builtin_platform_driver(__platform_driver) \
builtin_driver(__platform_driver, platform_driver_register)
/* module_platform_driver_probe() - Helper macro for drivers that don't do
* anything special in module init/exit. This eliminates a lot of
* boilerplate. Each module may only use this macro once, and
* calling it replaces module_init() and module_exit()
*/
#define module_platform_driver_probe(__platform_driver, __platform_probe) \
static int __init __platform_driver##_init(void) \
{ \
return platform_driver_probe(&(__platform_driver), \
__platform_probe); \
} \
module_init(__platform_driver##_init); \
static void __exit __platform_driver##_exit(void) \
{ \
platform_driver_unregister(&(__platform_driver)); \
} \
module_exit(__platform_driver##_exit);
/* builtin_platform_driver_probe() - Helper macro for drivers that don't do
* anything special in device init. This eliminates some boilerplate. Each
* driver may only use this macro once, and using it replaces device_initcall.
* This is meant to be a parallel of module_platform_driver_probe above, but
* without the __exit parts.
*/
#define builtin_platform_driver_probe(__platform_driver, __platform_probe) \
static int __init __platform_driver##_init(void) \
{ \
return platform_driver_probe(&(__platform_driver), \
__platform_probe); \
} \
device_initcall(__platform_driver##_init); \
#define platform_create_bundle(driver, probe, res, n_res, data, size) \
__platform_create_bundle(driver, probe, res, n_res, data, size, THIS_MODULE)
extern struct platform_device *__platform_create_bundle(
struct platform_driver *driver, int (*probe)(struct platform_device *),
struct resource *res, unsigned int n_res,
const void *data, size_t size, struct module *module);
/* early platform driver interface */
struct early_platform_driver {
const char *class_str;
struct platform_driver *pdrv;
struct list_head list;
int requested_id;
char *buffer;
int bufsize;
};
#define EARLY_PLATFORM_ID_UNSET -2
#define EARLY_PLATFORM_ID_ERROR -3
extern int early_platform_driver_register(struct early_platform_driver *epdrv,
char *buf);
extern void early_platform_add_devices(struct platform_device **devs, int num);
static inline int is_early_platform_device(struct platform_device *pdev)
{
return !pdev->dev.driver;
}
extern void early_platform_driver_register_all(char *class_str);
extern int early_platform_driver_probe(char *class_str,
int nr_probe, int user_only);
extern void early_platform_cleanup(void);
#define early_platform_init(class_string, platdrv) \
early_platform_init_buffer(class_string, platdrv, NULL, 0)
#ifndef MODULE
#define early_platform_init_buffer(class_string, platdrv, buf, bufsiz) \
static __initdata struct early_platform_driver early_driver = { \
.class_str = class_string, \
.buffer = buf, \
.bufsize = bufsiz, \
.pdrv = platdrv, \
.requested_id = EARLY_PLATFORM_ID_UNSET, \
}; \
static int __init early_platform_driver_setup_func(char *buffer) \
{ \
return early_platform_driver_register(&early_driver, buffer); \
} \
early_param(class_string, early_platform_driver_setup_func)
#else /* MODULE */
#define early_platform_init_buffer(class_string, platdrv, buf, bufsiz) \
static inline char *early_platform_driver_setup_func(void) \
{ \
return bufsiz ? buf : NULL; \
}
#endif /* MODULE */
#ifdef CONFIG_SUSPEND
extern int platform_pm_suspend(struct device *dev);
extern int platform_pm_resume(struct device *dev);
#else
#define platform_pm_suspend NULL
#define platform_pm_resume NULL
#endif
#ifdef CONFIG_HIBERNATE_CALLBACKS
extern int platform_pm_freeze(struct device *dev);
extern int platform_pm_thaw(struct device *dev);
extern int platform_pm_poweroff(struct device *dev);
extern int platform_pm_restore(struct device *dev);
#else
#define platform_pm_freeze NULL
#define platform_pm_thaw NULL
#define platform_pm_poweroff NULL
#define platform_pm_restore NULL
#endif
#ifdef CONFIG_PM_SLEEP
#define USE_PLATFORM_PM_SLEEP_OPS \
.suspend = platform_pm_suspend, \
.resume = platform_pm_resume, \
.freeze = platform_pm_freeze, \
.thaw = platform_pm_thaw, \
.poweroff = platform_pm_poweroff, \
.restore = platform_pm_restore,
#else
#define USE_PLATFORM_PM_SLEEP_OPS
#endif
#endif /* _PLATFORM_DEVICE_H_ */
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