From 13977091a988fb0d21821c2221ddc920eba36b79 Mon Sep 17 00:00:00 2001 From: Magnus Damm Date: Mon, 30 Mar 2009 14:37:25 -0700 Subject: Driver Core: early platform driver V3 of the early platform driver implementation. Platform drivers are great for embedded platforms because we can separate driver configuration from the actual driver. So base addresses, interrupts and other configuration can be kept with the processor or board code, and the platform driver can be reused by many different platforms. For early devices we have nothing today. For instance, to configure early timers and early serial ports we cannot use platform devices. This because the setup order during boot. Timers are needed before the platform driver core code is available. The same goes for early printk support. Early in this case means before initcalls. These early drivers today have their configuration either hard coded or they receive it using some special configuration method. This is working quite well, but if we want to support both regular kernel modules and early devices then we need to have two ways of configuring the same driver. A single way would be better. The early platform driver patch is basically a set of functions that allow drivers to register themselves and architecture code to locate them and probe. Registration happens through early_param(). The time for the probe is decided by the architecture code. See Documentation/driver-model/platform.txt for more details. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Magnus Damm Cc: Paul Mundt Cc: Kay Sievers Cc: David Brownell Cc: Tejun Heo Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman --- include/linux/platform_device.h | 42 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 42 insertions(+) (limited to 'include/linux/platform_device.h') diff --git a/include/linux/platform_device.h b/include/linux/platform_device.h index 76e470a299b..72736fd8223 100644 --- a/include/linux/platform_device.h +++ b/include/linux/platform_device.h @@ -77,4 +77,46 @@ extern int platform_driver_probe(struct platform_driver *driver, #define platform_get_drvdata(_dev) dev_get_drvdata(&(_dev)->dev) #define platform_set_drvdata(_dev,data) dev_set_drvdata(&(_dev)->dev, (data)) +/* early platform driver interface */ +struct early_platform_driver { + const char *class_str; + struct platform_driver *pdrv; + struct list_head list; + int requested_id; +}; + +#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); + + +#ifndef MODULE +#define early_platform_init(class_string, platform_driver) \ +static __initdata struct early_platform_driver early_driver = { \ + .class_str = class_string, \ + .pdrv = platform_driver, \ + .requested_id = EARLY_PLATFORM_ID_UNSET, \ +}; \ +static int __init early_platform_driver_setup_func(char *buf) \ +{ \ + return early_platform_driver_register(&early_driver, buf); \ +} \ +early_param(class_string, early_platform_driver_setup_func) +#else /* MODULE */ +#define early_platform_init(class_string, platform_driver) +#endif /* MODULE */ + #endif /* _PLATFORM_DEVICE_H_ */ -- cgit v1.2.3-70-g09d2 From e67c85626cd02e306da1b4195bfaf68d61050796 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Sun, 8 Mar 2009 23:13:32 +0800 Subject: Revert driver core: move platform_data into platform_device This reverts commit 006f4571a15fae3a0575f2a0f9e9b63b3d1012f8: This patch moves platform_data from struct device into struct platform_device, based on the two ideas: 1. Now all platform_driver is registered by platform_driver_register, which makes probe()/release()/... of platform_driver passed parameter of platform_device *, so platform driver can get platform_data from platform_device; 2. Other kind of devices do not need to use platform_data, we can decrease size of device if moving it to platform_device. Taking into consideration of thousands of files to be fixed and they can't be finished in one night(maybe it will take a long time), so we keep platform_data in device to allow two kind of cases coexist until all platform devices pass its platfrom data from platform_device->platform_data. All patches to do this kind of conversion are welcome. As we don't really want to do it, it was a bad idea. Cc: David Brownell Cc: Ming Lei Signed-off-by: Greg Kroah-Hartman --- drivers/base/platform.c | 3 --- include/linux/device.h | 9 ++------- include/linux/platform_device.h | 1 - 3 files changed, 2 insertions(+), 11 deletions(-) (limited to 'include/linux/platform_device.h') diff --git a/drivers/base/platform.c b/drivers/base/platform.c index d1d0ee43192..8b4708e0624 100644 --- a/drivers/base/platform.c +++ b/drivers/base/platform.c @@ -217,7 +217,6 @@ int platform_device_add_data(struct platform_device *pdev, const void *data, if (d) { memcpy(d, data, size); pdev->dev.platform_data = d; - pdev->platform_data = d; } return d ? 0 : -ENOMEM; } @@ -247,8 +246,6 @@ int platform_device_add(struct platform_device *pdev) else dev_set_name(&pdev->dev, pdev->name); - pdev->platform_data = pdev->dev.platform_data; - for (i = 0; i < pdev->num_resources; i++) { struct resource *p, *r = &pdev->resource[i]; diff --git a/include/linux/device.h b/include/linux/device.h index 6a69caaac18..5d5c197bad4 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -384,13 +384,8 @@ struct device { struct device_driver *driver; /* which driver has allocated this device */ void *driver_data; /* data private to the driver */ - - void *platform_data; /* We will remove platform_data - field if all platform devices - pass its platform specific data - from platform_device->platform_data, - other kind of devices should not - use platform_data. */ + void *platform_data; /* Platform specific data, device + core doesn't touch it */ struct dev_pm_info power; #ifdef CONFIG_NUMA diff --git a/include/linux/platform_device.h b/include/linux/platform_device.h index 72736fd8223..b67bb5d7b22 100644 --- a/include/linux/platform_device.h +++ b/include/linux/platform_device.h @@ -20,7 +20,6 @@ struct platform_device { struct device dev; u32 num_resources; struct resource * resource; - void *platform_data; struct platform_device_id *id_entry; }; -- cgit v1.2.3-70-g09d2