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 --- drivers/base/platform.c | 239 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 239 insertions(+) (limited to 'drivers/base/platform.c') diff --git a/drivers/base/platform.c b/drivers/base/platform.c index d2198f64ad4..b5b6c973a2e 100644 --- a/drivers/base/platform.c +++ b/drivers/base/platform.c @@ -990,6 +990,8 @@ int __init platform_bus_init(void) { int error; + early_platform_cleanup(); + error = device_register(&platform_bus); if (error) return error; @@ -1020,3 +1022,240 @@ u64 dma_get_required_mask(struct device *dev) } EXPORT_SYMBOL_GPL(dma_get_required_mask); #endif + +static __initdata LIST_HEAD(early_platform_driver_list); +static __initdata LIST_HEAD(early_platform_device_list); + +/** + * early_platform_driver_register + * @edrv: early_platform driver structure + * @buf: string passed from early_param() + */ +int __init early_platform_driver_register(struct early_platform_driver *epdrv, + char *buf) +{ + unsigned long index; + int n; + + /* Simply add the driver to the end of the global list. + * Drivers will by default be put on the list in compiled-in order. + */ + if (!epdrv->list.next) { + INIT_LIST_HEAD(&epdrv->list); + list_add_tail(&epdrv->list, &early_platform_driver_list); + } + + /* If the user has specified device then make sure the driver + * gets prioritized. The driver of the last device specified on + * command line will be put first on the list. + */ + n = strlen(epdrv->pdrv->driver.name); + if (buf && !strncmp(buf, epdrv->pdrv->driver.name, n)) { + list_move(&epdrv->list, &early_platform_driver_list); + + if (!strcmp(buf, epdrv->pdrv->driver.name)) + epdrv->requested_id = -1; + else if (buf[n] == '.' && strict_strtoul(&buf[n + 1], 10, + &index) == 0) + epdrv->requested_id = index; + else + epdrv->requested_id = EARLY_PLATFORM_ID_ERROR; + } + + return 0; +} + +/** + * early_platform_add_devices - add a numbers of early platform devices + * @devs: array of early platform devices to add + * @num: number of early platform devices in array + */ +void __init early_platform_add_devices(struct platform_device **devs, int num) +{ + struct device *dev; + int i; + + /* simply add the devices to list */ + for (i = 0; i < num; i++) { + dev = &devs[i]->dev; + + if (!dev->devres_head.next) { + INIT_LIST_HEAD(&dev->devres_head); + list_add_tail(&dev->devres_head, + &early_platform_device_list); + } + } +} + +/** + * early_platform_driver_register_all + * @class_str: string to identify early platform driver class + */ +void __init early_platform_driver_register_all(char *class_str) +{ + /* The "class_str" parameter may or may not be present on the kernel + * command line. If it is present then there may be more than one + * matching parameter. + * + * Since we register our early platform drivers using early_param() + * we need to make sure that they also get registered in the case + * when the parameter is missing from the kernel command line. + * + * We use parse_early_options() to make sure the early_param() gets + * called at least once. The early_param() may be called more than + * once since the name of the preferred device may be specified on + * the kernel command line. early_platform_driver_register() handles + * this case for us. + */ + parse_early_options(class_str); +} + +/** + * early_platform_match + * @edrv: early platform driver structure + * @id: id to match against + */ +static __init struct platform_device * +early_platform_match(struct early_platform_driver *epdrv, int id) +{ + struct platform_device *pd; + + list_for_each_entry(pd, &early_platform_device_list, dev.devres_head) + if (platform_match(&pd->dev, &epdrv->pdrv->driver)) + if (pd->id == id) + return pd; + + return NULL; +} + +/** + * early_platform_left + * @edrv: early platform driver structure + * @id: return true if id or above exists + */ +static __init int early_platform_left(struct early_platform_driver *epdrv, + int id) +{ + struct platform_device *pd; + + list_for_each_entry(pd, &early_platform_device_list, dev.devres_head) + if (platform_match(&pd->dev, &epdrv->pdrv->driver)) + if (pd->id >= id) + return 1; + + return 0; +} + +/** + * early_platform_driver_probe_id + * @class_str: string to identify early platform driver class + * @id: id to match against + * @nr_probe: number of platform devices to successfully probe before exiting + */ +static int __init early_platform_driver_probe_id(char *class_str, + int id, + int nr_probe) +{ + struct early_platform_driver *epdrv; + struct platform_device *match; + int match_id; + int n = 0; + int left = 0; + + list_for_each_entry(epdrv, &early_platform_driver_list, list) { + /* only use drivers matching our class_str */ + if (strcmp(class_str, epdrv->class_str)) + continue; + + if (id == -2) { + match_id = epdrv->requested_id; + left = 1; + + } else { + match_id = id; + left += early_platform_left(epdrv, id); + + /* skip requested id */ + switch (epdrv->requested_id) { + case EARLY_PLATFORM_ID_ERROR: + case EARLY_PLATFORM_ID_UNSET: + break; + default: + if (epdrv->requested_id == id) + match_id = EARLY_PLATFORM_ID_UNSET; + } + } + + switch (match_id) { + case EARLY_PLATFORM_ID_ERROR: + pr_warning("%s: unable to parse %s parameter\n", + class_str, epdrv->pdrv->driver.name); + /* fall-through */ + case EARLY_PLATFORM_ID_UNSET: + match = NULL; + break; + default: + match = early_platform_match(epdrv, match_id); + } + + if (match) { + if (epdrv->pdrv->probe(match)) + pr_warning("%s: unable to probe %s early.\n", + class_str, match->name); + else + n++; + } + + if (n >= nr_probe) + break; + } + + if (left) + return n; + else + return -ENODEV; +} + +/** + * early_platform_driver_probe + * @class_str: string to identify early platform driver class + * @nr_probe: number of platform devices to successfully probe before exiting + * @user_only: only probe user specified early platform devices + */ +int __init early_platform_driver_probe(char *class_str, + int nr_probe, + int user_only) +{ + int k, n, i; + + n = 0; + for (i = -2; n < nr_probe; i++) { + k = early_platform_driver_probe_id(class_str, i, nr_probe - n); + + if (k < 0) + break; + + n += k; + + if (user_only) + break; + } + + return n; +} + +/** + * early_platform_cleanup - clean up early platform code + */ +void __init early_platform_cleanup(void) +{ + struct platform_device *pd, *pd2; + + /* clean up the devres list used to chain devices */ + list_for_each_entry_safe(pd, pd2, &early_platform_device_list, + dev.devres_head) { + list_del(&pd->dev.devres_head); + memset(&pd->dev.devres_head, 0, sizeof(pd->dev.devres_head)); + } +} + -- cgit v1.2.3-70-g09d2 From d86c1302c58e4d4ebd99d459c2daff13613ac7f4 Mon Sep 17 00:00:00 2001 From: Randy Dunlap Date: Tue, 21 Apr 2009 07:22:53 -0700 Subject: Driver core: platform: fix kernel-doc warnings Fix function parameter notation in platform.c; fixes kernel-doc warnings. Signed-off-by: Randy Dunlap Signed-off-by: Greg Kroah-Hartman --- drivers/base/platform.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'drivers/base/platform.c') diff --git a/drivers/base/platform.c b/drivers/base/platform.c index b5b6c973a2e..ec5400c3202 100644 --- a/drivers/base/platform.c +++ b/drivers/base/platform.c @@ -1028,7 +1028,7 @@ static __initdata LIST_HEAD(early_platform_device_list); /** * early_platform_driver_register - * @edrv: early_platform driver structure + * @epdrv: early_platform driver structure * @buf: string passed from early_param() */ int __init early_platform_driver_register(struct early_platform_driver *epdrv, @@ -1112,7 +1112,7 @@ void __init early_platform_driver_register_all(char *class_str) /** * early_platform_match - * @edrv: early platform driver structure + * @epdrv: early platform driver structure * @id: id to match against */ static __init struct platform_device * @@ -1130,7 +1130,7 @@ early_platform_match(struct early_platform_driver *epdrv, int id) /** * early_platform_left - * @edrv: early platform driver structure + * @epdrv: early platform driver structure * @id: return true if id or above exists */ static __init int early_platform_left(struct early_platform_driver *epdrv, -- cgit v1.2.3-70-g09d2 From bee86321b7b2312fbb62f4cb903eba1cca45e8ad Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Fri, 13 Mar 2009 23:06:59 +0800 Subject: Revert driver core: fix passing platform_data This reverts commit ce21c7bcd796fc4f45d48781b7e85f493cc55ee5: We will remove platform_data field from struct device until all platform devices pass its specific data from platfom_device and all platform drivers use platform specific data passed by platform_device->platform_data. This kind of conversion will need a long time, for thousands of files is affected. To make the conversion easily, we allow platform specific data passed by struct device or struct platform_device and platform driver may use it from struct device or struct platform_device. As we really don't want to do this at all. Cc: David Brownell Cc: Ming Lei Signed-off-by: Greg Kroah-Hartman --- drivers/base/platform.c | 15 +-------------- 1 file changed, 1 insertion(+), 14 deletions(-) (limited to 'drivers/base/platform.c') diff --git a/drivers/base/platform.c b/drivers/base/platform.c index ec5400c3202..d1d0ee43192 100644 --- a/drivers/base/platform.c +++ b/drivers/base/platform.c @@ -247,20 +247,7 @@ int platform_device_add(struct platform_device *pdev) else dev_set_name(&pdev->dev, pdev->name); - /* We will remove platform_data field from struct device - * if all platform devices pass its platform specific data - * from platform_device. The conversion is going to be a - * long time, so we allow the two cases coexist to make - * this kind of fix more easily*/ - if (pdev->platform_data && pdev->dev.platform_data) { - printk(KERN_ERR - "%s: use which platform_data?\n", - dev_name(&pdev->dev)); - } else if (pdev->platform_data) { - pdev->dev.platform_data = pdev->platform_data; - } else if (pdev->dev.platform_data) { - pdev->platform_data = pdev->dev.platform_data; - } + pdev->platform_data = pdev->dev.platform_data; for (i = 0; i < pdev->num_resources; i++) { struct resource *p, *r = &pdev->resource[i]; -- 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 'drivers/base/platform.c') 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