From 2dfe47b26ba0bf72974ae4ca2bb86b211a78596b Mon Sep 17 00:00:00 2001 From: Eric Miao Date: Tue, 30 Dec 2008 14:20:59 +0800 Subject: [PATCH] platform: introduce module id table for platform devices Now platform_device is being widely used on SoC processors where the peripherals are attached to the system bus, which is simple enough. However, silicon IPs for these SoCs are usually shared heavily across a family of processors, even products from different companies. This makes the original simple driver name based matching insufficient, or simply not straight-forward. Introduce a module id table for platform devices, and makes it clear that a platform driver is able to support some shared IP and handle slight differences across different platforms (by 'driver_data'). Module alias is handled automatically when a MODULE_DEVICE_TABLE() is defined. To not disturb the current platform drivers too much, the matched id entry is recorded and can be retrieved by platform_get_device_id(). Signed-off-by: Eric Miao --- drivers/base/platform.c | 23 ++++++++++++++++++++++- include/linux/mod_devicetable.h | 9 +++++++++ include/linux/platform_device.h | 6 ++++++ scripts/mod/file2alias.c | 12 ++++++++++++ 4 files changed, 49 insertions(+), 1 deletions(-) diff --git a/drivers/base/platform.c b/drivers/base/platform.c index d0591f0..ae65607 100644 --- a/drivers/base/platform.c +++ b/drivers/base/platform.c @@ -587,10 +587,25 @@ static int platform_uevent(struct device *dev, struct kobj_uevent_env *env) { struct platform_device *pdev = to_platform_device(dev); - add_uevent_var(env, "MODALIAS=platform:%s", pdev->name); + add_uevent_var(env, "MODALIAS=%s%s", PLATFORM_MODULE_PREFIX, + (pdev->id_entry) ? pdev->id_entry->name : pdev->name); return 0; } +static const struct platform_device_id *platform_match_id( + struct platform_device_id *id, + struct platform_device *pdev) +{ + while (id->name[0]) { + if (strcmp(pdev->name, id->name) == 0) { + pdev->id_entry = id; + return id; + } + id++; + } + return NULL; +} + /** * platform_match - bind platform device to platform driver. * @dev: device. @@ -607,7 +622,13 @@ static int platform_uevent(struct device *dev, struct kobj_uevent_env *env) static int platform_match(struct device *dev, struct device_driver *drv) { struct platform_device *pdev = to_platform_device(dev); + struct platform_driver *pdrv = to_platform_driver(drv); + + /* match against the id table first */ + if (pdrv->id_table) + return platform_match_id(pdrv->id_table, pdev) != NULL; + /* fall-back to driver name match */ return (strncmp(pdev->name, drv->name, BUS_ID_SIZE) == 0); } diff --git a/include/linux/mod_devicetable.h b/include/linux/mod_devicetable.h index 97b91d1..05542d3 100644 --- a/include/linux/mod_devicetable.h +++ b/include/linux/mod_devicetable.h @@ -447,4 +447,13 @@ struct dmi_system_id { #define DMI_MATCH(a, b) { a, b } +#define PLATFORM_NAME_SIZE 20 +#define PLATFORM_MODULE_PREFIX "platform:" + +struct platform_device_id { + char name[PLATFORM_NAME_SIZE]; + kernel_ulong_t driver_data + __attribute__((aligned(sizeof(kernel_ulong_t)))); +}; + #endif /* LINUX_MOD_DEVICETABLE_H */ diff --git a/include/linux/platform_device.h b/include/linux/platform_device.h index 4b8cc6a..7edc570 100644 --- a/include/linux/platform_device.h +++ b/include/linux/platform_device.h @@ -12,6 +12,7 @@ #define _PLATFORM_DEVICE_H_ #include +#include struct platform_device { const char * name; @@ -19,8 +20,12 @@ struct platform_device { struct device dev; u32 num_resources; struct resource * resource; + + struct platform_device_id *id_entry; }; +#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 *); @@ -57,6 +62,7 @@ struct platform_driver { int (*resume)(struct platform_device *); struct pm_ext_ops *pm; struct device_driver driver; + struct platform_device_id *id_table; }; extern int platform_driver_register(struct platform_driver *); diff --git a/scripts/mod/file2alias.c b/scripts/mod/file2alias.c index d4dc222..f71f5e6 100644 --- a/scripts/mod/file2alias.c +++ b/scripts/mod/file2alias.c @@ -696,6 +696,14 @@ static int do_dmi_entry(const char *filename, struct dmi_system_id *id, strcat(alias, ":"); return 1; } + +static int do_platform_entry(const char *filename, + struct platform_device_id *id, char *alias) +{ + sprintf(alias, PLATFORM_MODULE_PREFIX "%s", id->name); + return 1; +} + /* Ignore any prefix, eg. some architectures prepend _ */ static inline int sym_is(const char *symbol, const char *name) { @@ -835,6 +843,10 @@ void handle_moddevtable(struct module *mod, struct elf_info *info, do_table(symval, sym->st_size, sizeof(struct dmi_system_id), "dmi", do_dmi_entry, mod); + else if (sym_is(symname, "__mod_platform_device_table")) + do_table(symval, sym->st_size, + sizeof(struct platform_device_id), "platform", + do_platform_entry, mod); free(zeros); } -- 1.6.0.4