diff options
Diffstat (limited to 'drivers/base')
| -rw-r--r-- | drivers/base/Kconfig | 3 | ||||
| -rw-r--r-- | drivers/base/Makefile | 1 | ||||
| -rw-r--r-- | drivers/base/base.h | 6 | ||||
| -rw-r--r-- | drivers/base/bus.c | 6 | ||||
| -rw-r--r-- | drivers/base/core.c | 2 | ||||
| -rw-r--r-- | drivers/base/cpu.c | 11 | ||||
| -rw-r--r-- | drivers/base/dd.c | 148 | ||||
| -rw-r--r-- | drivers/base/driver.c | 35 | ||||
| -rw-r--r-- | drivers/base/soc.c | 183 |
9 files changed, 362 insertions, 33 deletions
diff --git a/drivers/base/Kconfig b/drivers/base/Kconfig index 7be9f79018e9..9aa618acfe97 100644 --- a/drivers/base/Kconfig +++ b/drivers/base/Kconfig @@ -176,6 +176,9 @@ config GENERIC_CPU_DEVICES bool default n +config SOC_BUS + bool + source "drivers/base/regmap/Kconfig" config DMA_SHARED_BUFFER diff --git a/drivers/base/Makefile b/drivers/base/Makefile index 610f9997a403..b6d1b9c4200c 100644 --- a/drivers/base/Makefile +++ b/drivers/base/Makefile @@ -19,6 +19,7 @@ obj-$(CONFIG_MODULES) += module.o endif obj-$(CONFIG_SYS_HYPERVISOR) += hypervisor.o obj-$(CONFIG_REGMAP) += regmap/ +obj-$(CONFIG_SOC_BUS) += soc.o ccflags-$(CONFIG_DEBUG_DRIVER) := -DDEBUG diff --git a/drivers/base/base.h b/drivers/base/base.h index b858dfd9a37c..6ee17bb391a9 100644 --- a/drivers/base/base.h +++ b/drivers/base/base.h @@ -59,6 +59,10 @@ struct driver_private { * @knode_parent - node in sibling list * @knode_driver - node in driver list * @knode_bus - node in bus list + * @deferred_probe - entry in deferred_probe_list which is used to retry the + * binding of drivers which were unable to get all the resources needed by + * the device; typically because it depends on another driver getting + * probed first. * @driver_data - private pointer for driver specific info. Will turn into a * list soon. * @device - pointer back to the struct class that this structure is @@ -71,6 +75,7 @@ struct device_private { struct klist_node knode_parent; struct klist_node knode_driver; struct klist_node knode_bus; + struct list_head deferred_probe; void *driver_data; struct device *device; }; @@ -105,6 +110,7 @@ extern void bus_remove_driver(struct device_driver *drv); extern void driver_detach(struct device_driver *drv); extern int driver_probe_device(struct device_driver *drv, struct device *dev); +extern void driver_deferred_probe_del(struct device *dev); static inline int driver_match_device(struct device_driver *drv, struct device *dev) { diff --git a/drivers/base/bus.c b/drivers/base/bus.c index 40fb12288ce2..26a06b801b5b 100644 --- a/drivers/base/bus.c +++ b/drivers/base/bus.c @@ -1194,13 +1194,15 @@ EXPORT_SYMBOL_GPL(subsys_interface_register); void subsys_interface_unregister(struct subsys_interface *sif) { - struct bus_type *subsys = sif->subsys; + struct bus_type *subsys; struct subsys_dev_iter iter; struct device *dev; - if (!sif) + if (!sif || !sif->subsys) return; + subsys = sif->subsys; + mutex_lock(&subsys->p->mutex); list_del_init(&sif->node); if (sif->remove_dev) { diff --git a/drivers/base/core.c b/drivers/base/core.c index 74dda4f697f9..7050a75dde38 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -921,6 +921,7 @@ int device_private_init(struct device *dev) dev->p->device = dev; klist_init(&dev->p->klist_children, klist_children_get, klist_children_put); + INIT_LIST_HEAD(&dev->p->deferred_probe); return 0; } @@ -1188,6 +1189,7 @@ void device_del(struct device *dev) device_remove_file(dev, &uevent_attr); device_remove_attrs(dev); bus_remove_device(dev); + driver_deferred_probe_del(dev); /* * Some platform devices are driven without driver attached diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c index 4dabf5077c48..adf937bf4091 100644 --- a/drivers/base/cpu.c +++ b/drivers/base/cpu.c @@ -11,6 +11,7 @@ #include <linux/device.h> #include <linux/node.h> #include <linux/gfp.h> +#include <linux/slab.h> #include <linux/percpu.h> #include "base.h" @@ -244,6 +245,9 @@ int __cpuinit register_cpu(struct cpu *cpu, int num) cpu->dev.id = num; cpu->dev.bus = &cpu_subsys; cpu->dev.release = cpu_device_release; +#ifdef CONFIG_ARCH_HAS_CPU_AUTOPROBE + cpu->dev.bus->uevent = arch_cpu_uevent; +#endif error = device_register(&cpu->dev); if (!error && cpu->hotpluggable) register_cpu_control(cpu); @@ -268,6 +272,10 @@ struct device *get_cpu_device(unsigned cpu) } EXPORT_SYMBOL_GPL(get_cpu_device); +#ifdef CONFIG_ARCH_HAS_CPU_AUTOPROBE +static DEVICE_ATTR(modalias, 0444, arch_print_cpu_modalias, NULL); +#endif + static struct attribute *cpu_root_attrs[] = { #ifdef CONFIG_ARCH_CPU_PROBE_RELEASE &dev_attr_probe.attr, @@ -278,6 +286,9 @@ static struct attribute *cpu_root_attrs[] = { &cpu_attrs[2].attr.attr, &dev_attr_kernel_max.attr, &dev_attr_offline.attr, +#ifdef CONFIG_ARCH_HAS_CPU_AUTOPROBE + &dev_attr_modalias.attr, +#endif NULL }; diff --git a/drivers/base/dd.c b/drivers/base/dd.c index 142e3d600f14..1b1cbb571d38 100644 --- a/drivers/base/dd.c +++ b/drivers/base/dd.c @@ -28,6 +28,141 @@ #include "base.h" #include "power/power.h" +/* + * Deferred Probe infrastructure. + * + * Sometimes driver probe order matters, but the kernel doesn't always have + * dependency information which means some drivers will get probed before a + * resource it depends on is available. For example, an SDHCI driver may + * first need a GPIO line from an i2c GPIO controller before it can be + * initialized. If a required resource is not available yet, a driver can + * request probing to be deferred by returning -EPROBE_DEFER from its probe hook + * + * Deferred probe maintains two lists of devices, a pending list and an active + * list. A driver returning -EPROBE_DEFER causes the device to be added to the + * pending list. A successful driver probe will trigger moving all devices + * from the pending to the active list so that the workqueue will eventually + * retry them. + * + * The deferred_probe_mutex must be held any time the deferred_probe_*_list + * of the (struct device*)->p->deferred_probe pointers are manipulated + */ +static DEFINE_MUTEX(deferred_probe_mutex); +static LIST_HEAD(deferred_probe_pending_list); +static LIST_HEAD(deferred_probe_active_list); +static struct workqueue_struct *deferred_wq; + +/** + * deferred_probe_work_func() - Retry probing devices in the active list. + */ +static void deferred_probe_work_func(struct work_struct *work) +{ + struct device *dev; + struct device_private *private; + /* + * This block processes every device in the deferred 'active' list. + * Each device is removed from the active list and passed to + * bus_probe_device() to re-attempt the probe. The loop continues + * until every device in the active list is removed and retried. + * + * Note: Once the device is removed from the list and the mutex is + * released, it is possible for the device get freed by another thread + * and cause a illegal pointer dereference. This code uses + * get/put_device() to ensure the device structure cannot disappear + * from under our feet. + */ + mutex_lock(&deferred_probe_mutex); + while (!list_empty(&deferred_probe_active_list)) { + private = list_first_entry(&deferred_probe_active_list, + typeof(*dev->p), deferred_probe); + dev = private->device; + list_del_init(&private->deferred_probe); + + get_device(dev); + + /* + * Drop the mutex while probing each device; the probe path may + * manipulate the deferred list + */ + mutex_unlock(&deferred_probe_mutex); + dev_dbg(dev, "Retrying from deferred list\n"); + bus_probe_device(dev); + mutex_lock(&deferred_probe_mutex); + + put_device(dev); + } + mutex_unlock(&deferred_probe_mutex); +} +static DECLARE_WORK(deferred_probe_work, deferred_probe_work_func); + +static void driver_deferred_probe_add(struct device *dev) +{ + mutex_lock(&deferred_probe_mutex); + if (list_empty(&dev->p->deferred_probe)) { + dev_dbg(dev, "Added to deferred list\n"); + list_add(&dev->p->deferred_probe, &deferred_probe_pending_list); + } + mutex_unlock(&deferred_probe_mutex); +} + +void driver_deferred_probe_del(struct device *dev) +{ + mutex_lock(&deferred_probe_mutex); + if (!list_empty(&dev->p->deferred_probe)) { + dev_dbg(dev, "Removed from deferred list\n"); + list_del_init(&dev->p->deferred_probe); + } + mutex_unlock(&deferred_probe_mutex); +} + +static bool driver_deferred_probe_enable = false; +/** + * driver_deferred_probe_trigger() - Kick off re-probing deferred devices + * + * This functions moves all devices from the pending list to the active + * list and schedules the deferred probe workqueue to process them. It + * should be called anytime a driver is successfully bound to a device. + */ +static void driver_deferred_probe_trigger(void) +{ + if (!driver_deferred_probe_enable) + return; + + /* + * A successful probe means that all the devices in the pending list + * should be triggered to be reprobed. Move all the deferred devices + * into the active list so they can be retried by the workqueue + */ + mutex_lock(&deferred_probe_mutex); + list_splice_tail_init(&deferred_probe_pending_list, + &deferred_probe_active_list); + mutex_unlock(&deferred_probe_mutex); + + /* + * Kick the re-probe thread. It may already be scheduled, but it is + * safe to kick it again. + */ + queue_work(deferred_wq, &deferred_probe_work); +} + +/** + * deferred_probe_initcall() - Enable probing of deferred devices + * + * We don't want to get in the way when the bulk of drivers are getting probed. + * Instead, this initcall makes sure that deferred probing is delayed until + * late_initcall time. + */ +static int deferred_probe_initcall(void) +{ + deferred_wq = create_singlethread_workqueue("deferwq"); + if (WARN_ON(!deferred_wq)) + return -ENOMEM; + + driver_deferred_probe_enable = true; + driver_deferred_probe_trigger(); + return 0; +} +late_initcall(deferred_probe_initcall); static void driver_bound(struct device *dev) { @@ -42,6 +177,13 @@ static void driver_bound(struct device *dev) klist_add_tail(&dev->p->knode_driver, &dev->driver->p->klist_devices); + /* + * Make sure the device is no longer in one of the deferred lists and + * kick off retrying all pending devices + */ + driver_deferred_probe_del(dev); + driver_deferred_probe_trigger(); + if (dev->bus) blocking_notifier_call_chain(&dev->bus->p->bus_notifier, BUS_NOTIFY_BOUND_DRIVER, dev); @@ -142,7 +284,11 @@ probe_failed: driver_sysfs_remove(dev); dev->driver = NULL; - if (ret != -ENODEV && ret != -ENXIO) { + if (ret == -EPROBE_DEFER) { + /* Driver requested deferred probing */ + dev_info(dev, "Driver %s requests probe deferral\n", drv->name); + driver_deferred_probe_add(dev); + } else if (ret != -ENODEV && ret != -ENXIO) { /* driver matched but the probe failed */ printk(KERN_WARNING "%s: probe of %s failed with error %d\n", diff --git a/drivers/base/driver.c b/drivers/base/driver.c index b631f7c59453..60e4f77ca662 100644 --- a/drivers/base/driver.c +++ b/drivers/base/driver.c @@ -153,34 +153,6 @@ int driver_add_kobj(struct device_driver *drv, struct kobject *kobj, } EXPORT_SYMBOL_GPL(driver_add_kobj); -/** - * get_driver - increment driver reference count. - * @drv: driver. - */ -struct device_driver *get_driver(struct device_driver *drv) -{ - if (drv) { - struct driver_private *priv; - struct kobject *kobj; - - kobj = kobject_get(&drv->p->kobj); - priv = to_driver(kobj); - return priv->driver; - } - return NULL; -} -EXPORT_SYMBOL_GPL(get_driver); - -/** - * put_driver - decrement driver's refcount. - * @drv: driver. - */ -void put_driver(struct device_driver *drv) -{ - kobject_put(&drv->p->kobj); -} -EXPORT_SYMBOL_GPL(put_driver); - static int driver_add_groups(struct device_driver *drv, const struct attribute_group **groups) { @@ -234,7 +206,6 @@ int driver_register(struct device_driver *drv) other = driver_find(drv->name, drv->bus); if (other) { - put_driver(other); printk(KERN_ERR "Error: Driver '%s' is already registered, " "aborting...\n", drv->name); return -EBUSY; @@ -275,7 +246,9 @@ EXPORT_SYMBOL_GPL(driver_unregister); * Call kset_find_obj() to iterate over list of drivers on * a bus to find driver by name. Return driver if found. * - * Note that kset_find_obj increments driver's reference count. + * This routine provides no locking to prevent the driver it returns + * from being unregistered or unloaded while the caller is using it. + * The caller is responsible for preventing this. */ struct device_driver *driver_find(const char *name, struct bus_type *bus) { @@ -283,6 +256,8 @@ struct device_driver *driver_find(const char *name, struct bus_type *bus) struct driver_private *priv; if (k) { + /* Drop reference added by kset_find_obj() */ + kobject_put(k); priv = to_driver(k); return priv->driver; } diff --git a/drivers/base/soc.c b/drivers/base/soc.c new file mode 100644 index 000000000000..05f150382da8 --- /dev/null +++ b/drivers/base/soc.c @@ -0,0 +1,183 @@ +/* + * Copyright (C) ST-Ericsson SA 2011 + * + * Author: Lee Jones <lee.jones@linaro.org> for ST-Ericsson. + * License terms: GNU General Public License (GPL), version 2 + */ + +#include <linux/sysfs.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/stat.h> +#include <linux/slab.h> +#include <linux/idr.h> +#include <linux/spinlock.h> +#include <linux/sys_soc.h> +#include <linux/err.h> + +static DEFINE_IDR(soc_ida); +static DEFINE_SPINLOCK(soc_lock); + +static ssize_t soc_info_get(struct device *dev, + struct device_attribute *attr, + char *buf); + +struct soc_device { + struct device dev; + struct soc_device_attribute *attr; + int soc_dev_num; +}; + +static struct bus_type soc_bus_type = { + .name = "soc", +}; + +static DEVICE_ATTR(machine, S_IRUGO, soc_info_get, NULL); +static DEVICE_ATTR(family, S_IRUGO, soc_info_get, NULL); +static DEVICE_ATTR(soc_id, S_IRUGO, soc_info_get, NULL); +static DEVICE_ATTR(revision, S_IRUGO, soc_info_get, NULL); + +struct device *soc_device_to_device(struct soc_device *soc_dev) +{ + return &soc_dev->dev; +} + +static mode_t soc_attribute_mode(struct kobject *kobj, + struct attribute *attr, + int index) +{ + struct device *dev = container_of(kobj, struct device, kobj); + struct soc_device *soc_dev = container_of(dev, struct soc_device, dev); + + if ((attr == &dev_attr_machine.attr) + && (soc_dev->attr->machine != NULL)) + return attr->mode; + if ((attr == &dev_attr_family.attr) + && (soc_dev->attr->family != NULL)) + return attr->mode; + if ((attr == &dev_attr_revision.attr) + && (soc_dev->attr->revision != NULL)) + return attr->mode; + if ((attr == &dev_attr_soc_id.attr) + && (soc_dev->attr->soc_id != NULL)) + return attr->mode; + + /* Unknown or unfilled attribute. */ + return 0; +} + +static ssize_t soc_info_get(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct soc_device *soc_dev = container_of(dev, struct soc_device, dev); + + if (attr == &dev_attr_machine) + return sprintf(buf, "%s\n", soc_dev->attr->machine); + if (attr == &dev_attr_family) + return sprintf(buf, "%s\n", soc_dev->attr->family); + if (attr == &dev_attr_revision) + return sprintf(buf, "%s\n", soc_dev->attr->revision); + if (attr == &dev_attr_soc_id) + return sprintf(buf, "%s\n", soc_dev->attr->soc_id); + + return -EINVAL; + +} + +static struct attribute *soc_attr[] = { + &dev_attr_machine.attr, + &dev_attr_family.attr, + &dev_attr_soc_id.attr, + &dev_attr_revision.attr, + NULL, +}; + +static const struct attribute_group soc_attr_group = { + .attrs = soc_attr, + .is_visible = soc_attribute_mode, +}; + +static const struct attribute_group *soc_attr_groups[] = { + &soc_attr_group, + NULL, +}; + +static void soc_release(struct device *dev) +{ + struct soc_device *soc_dev = container_of(dev, struct soc_device, dev); + + kfree(soc_dev); +} + +struct soc_device *soc_device_register(struct soc_device_attribute *soc_dev_attr) +{ + struct soc_device *soc_dev; + int ret; + + soc_dev = kzalloc(sizeof(*soc_dev), GFP_KERNEL); + if (!soc_dev) { + ret = -ENOMEM; + goto out1; + } + + /* Fetch a unique (reclaimable) SOC ID. */ + do { + if (!ida_pre_get(&soc_ida, GFP_KERNEL)) { + ret = -ENOMEM; + goto out2; + } + + spin_lock(&soc_lock); + ret = ida_get_new(&soc_ida, &soc_dev->soc_dev_num); + spin_unlock(&soc_lock); + + } while (ret == -EAGAIN); + + if (ret) + goto out2; + + soc_dev->attr = soc_dev_attr; + soc_dev->dev.bus = &soc_bus_type; + soc_dev->dev.groups = soc_attr_groups; + soc_dev->dev.release = soc_release; + + dev_set_name(&soc_dev->dev, "soc%d", soc_dev->soc_dev_num); + + ret = device_register(&soc_dev->dev); + if (ret) + goto out3; + + return soc_dev; + +out3: + ida_remove(&soc_ida, soc_dev->soc_dev_num); +out2: + kfree(soc_dev); +out1: + return ERR_PTR(ret); +} + +/* Ensure soc_dev->attr is freed prior to calling soc_device_unregister. */ +void soc_device_unregister(struct soc_device *soc_dev) +{ + ida_remove(&soc_ida, soc_dev->soc_dev_num); + + device_unregister(&soc_dev->dev); +} + +static int __init soc_bus_register(void) +{ + spin_lock_init(&soc_lock); + + return bus_register(&soc_bus_type); +} +core_initcall(soc_bus_register); + +static void __exit soc_bus_unregister(void) +{ + ida_destroy(&soc_ida); + + bus_unregister(&soc_bus_type); +} +module_exit(soc_bus_unregister); |