On Sat, Jan 31, 2009 at 10:49:17PM +0800, Eric Miao wrote:
> >From 334741bf2768a98e7babde6c2795151bfa0d57f6 Mon Sep 17 00:00:00 2001
> From: Eric Miao <[email protected]>
> Date: Tue, 30 Dec 2008 14:20:59 +0800
> Subject: 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 <[email protected]>
> ---
> drivers/base/platform.c | 21 ++++++++++++++++++++-
> include/linux/mod_devicetable.h | 9 +++++++++
> include/linux/platform_device.h | 6 ++++++
> scripts/mod/file2alias.c | 12 ++++++++++++
> 4 files changed, 47 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/base/platform.c b/drivers/base/platform.c
> index d0591f0..45bdc37 100644
> --- a/drivers/base/platform.c
> +++ b/drivers/base/platform.c
> @@ -587,7 +587,8 @@ 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;
> }
>
> @@ -604,10 +605,28 @@ static int platform_uevent(struct device *dev, struct kobj_uevent_env *env)
> * and compare it against the name of the driver. Return whether they match
> * or not.
> */
> +static const struct platform_device_id *platform_match_id(
> + const struct platform_device_id *id,
> + struct platform_device *pdev)
> +{
> + while (id->name[0]) {
> + if (strcmp(pdev->name, id->name) == 0)
> + return (pdev->id_entry = id);
> + id++;
> + }
> + return NULL;
> +}
> +
> 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..5201491 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[I2C_NAME_SIZE];
> + kernel_ulong_t driver_data
> + __attribute__((aligned(sizeof(kernel_ulong_t))));
> +};
> +
surely you mean PLATFORM_NAME_SIZE in this struct?
> #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 <linux/device.h>
> +#include <linux/mod_devicetable.h>
>
> 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;
> };
--
Ben ([email protected], http://www.fluff.org/)
'a smiley only costs 4 bytes'