[RFC 1/7] capebus: Core capebus support
Pantelis Antoniou
panto at antoniou-consulting.com
Wed Oct 31 12:52:07 EDT 2012
Introducing capebus; a bus that allows small boards (capes) to connect
to a complex SoC using simple expansion connectors.
Up to now to support these kind of boards, one had to hack the board files,
and do all sort of gymnastics to handle all the different cases of
conflict resolution.
Capebus provides abstractions that keep the pain to a minimum.
This part of the series is introducing the core capebus functionality
dealing with the basic bus & driver probe functions.
Signed-off-by: Pantelis Antoniou <panto at antoniou-consulting.com>
---
drivers/Kconfig | 2 +
drivers/Makefile | 3 +
drivers/capebus/Kconfig | 17 ++
drivers/capebus/Makefile | 8 +
drivers/capebus/capebus-driver.c | 608 +++++++++++++++++++++++++++++++++++++++
drivers/capebus/capebus-probe.c | 320 +++++++++++++++++++++
drivers/capebus/capebus-sysfs.c | 52 ++++
include/linux/capebus.h | 298 +++++++++++++++++++
8 files changed, 1308 insertions(+)
create mode 100644 drivers/capebus/Kconfig
create mode 100644 drivers/capebus/Makefile
create mode 100644 drivers/capebus/capebus-driver.c
create mode 100644 drivers/capebus/capebus-probe.c
create mode 100644 drivers/capebus/capebus-sysfs.c
create mode 100644 include/linux/capebus.h
diff --git a/drivers/Kconfig b/drivers/Kconfig
index dbdefa3..bfbe1d1 100644
--- a/drivers/Kconfig
+++ b/drivers/Kconfig
@@ -156,4 +156,6 @@ source "drivers/pwm/Kconfig"
source "drivers/irqchip/Kconfig"
+source "drivers/capebus/Kconfig"
+
endmenu
diff --git a/drivers/Makefile b/drivers/Makefile
index a16a8d0..d7a103b 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -145,3 +145,6 @@ obj-$(CONFIG_EXTCON) += extcon/
obj-$(CONFIG_MEMORY) += memory/
obj-$(CONFIG_IIO) += iio/
obj-$(CONFIG_VME_BUS) += vme/
+
+# Capebus
+obj-$(CONFIG_CAPEBUS) += capebus/
diff --git a/drivers/capebus/Kconfig b/drivers/capebus/Kconfig
new file mode 100644
index 0000000..cea1b68
--- /dev/null
+++ b/drivers/capebus/Kconfig
@@ -0,0 +1,17 @@
+#
+# Capebus core support
+#
+
+menu "CAPEBUS support"
+
+config CAPEBUS
+ bool "Capebus support"
+ default n
+ help
+ Enable to support capebus devices.
+
+source "drivers/capebus/boards/Kconfig"
+
+source "drivers/capebus/capes/Kconfig"
+
+endmenu
diff --git a/drivers/capebus/Makefile b/drivers/capebus/Makefile
new file mode 100644
index 0000000..45aa303
--- /dev/null
+++ b/drivers/capebus/Makefile
@@ -0,0 +1,8 @@
+#
+# Makefile for CAPEBUS devices
+#
+
+obj-$(CONFIG_CAPEBUS) += capebus-probe.o \
+ capebus-driver.o capebus-sysfs.o
+obj-$(CONFIG_CAPEBUS) += boards/
+obj-$(CONFIG_CAPEBUS) += capes/
diff --git a/drivers/capebus/capebus-driver.c b/drivers/capebus/capebus-driver.c
new file mode 100644
index 0000000..82b1d1b
--- /dev/null
+++ b/drivers/capebus/capebus-driver.c
@@ -0,0 +1,608 @@
+/*
+ * Capebus driver infrastructure
+ *
+ * Copyright (C) 2012 Pantelis Antoniou <panto at antoniou-consulting.com>
+ * Copyright (C) 2012 Texas Instruments Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/device.h>
+#include <linux/mempolicy.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/cpu.h>
+#include <linux/pm_runtime.h>
+#include <linux/suspend.h>
+
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_platform.h>
+
+#include <linux/capebus.h>
+
+/**
+ * capebus_match_device - Tell if a cape device structure has a
+ * matching cape device id structure
+ * @drv: the cape driver to match against
+ * @dev: the cape device structure to match against
+ *
+ * Used by a driver to check whether a cape device present in the
+ * system is in its list of supported devices. Returns the matching
+ * cape_device_id structure or %NULL if there is no match.
+ */
+static const struct cape_device_id *capebus_match_device(
+ struct cape_driver *drv, struct cape_dev *dev)
+{
+ struct cape_bus *bus = dev->bus;
+ struct cape_slot *slot = dev->slot;
+
+ BUG_ON(bus == NULL);
+ BUG_ON(slot == NULL);
+ BUG_ON(bus->ops == NULL);
+ BUG_ON(bus->ops->get_dev_id == NULL);
+
+ return bus->ops->get_dev_id(slot);
+}
+
+/**
+ * capebus_device_probe - check if a driver wants to claim a
+ * specific cape device
+ * @dev: cape device being probed
+ *
+ * returns 0 on success, else error.
+ * side-effect: cape_dev->driver is set to drv when drv claims cape_dev.
+ */
+static int capebus_device_probe(struct device *dev)
+{
+ const struct cape_device_id *id;
+ int error = 0;
+ struct cape_driver *drv;
+ struct cape_dev *cape_dev;
+ struct device *parent;
+
+ drv = to_cape_driver(dev->driver);
+ cape_dev = to_cape_dev(dev);
+ cape_dev = capebus_dev_get(cape_dev);
+
+ /* sanity checks */
+ if (cape_dev == NULL ||
+ cape_dev->bus == NULL || cape_dev->bus->ops == NULL ||
+ cape_dev->driver != NULL || drv->probe == NULL) {
+ error = -EINVAL;
+ goto err_no_sanity;
+ }
+
+ id = capebus_match_device(drv, cape_dev);
+ if (!id) {
+ error = -ENODEV;
+ goto err_no_match;
+ }
+
+ /* The parent device must be in active state when probing */
+ parent = cape_dev->dev.parent;
+ if (parent)
+ pm_runtime_get_sync(parent);
+
+ /* Unbound cape devices are always set to disabled and suspended.
+ * During probe, the device is set to enabled and active and the
+ * usage count is incremented. If the driver supports runtime PM,
+ * it should call pm_runtime_put_noidle() in its probe routine and
+ * pm_runtime_get_noresume() in its remove routine.
+ */
+ pm_runtime_get_noresume(&cape_dev->dev);
+ pm_runtime_set_active(&cape_dev->dev);
+ pm_runtime_enable(&cape_dev->dev);
+
+ /* call the driver's probe method */
+ error = drv->probe(cape_dev, id);
+
+ /* release the parent no matter what */
+ if (parent)
+ pm_runtime_put(parent);
+
+ if (error != 0)
+ goto err_probe_fail;
+
+ /* call the probed bus method */
+ if (cape_dev->bus->ops->dev_probed != NULL) {
+ error = cape_dev->bus->ops->dev_probed(cape_dev);
+ if (error != 0)
+ goto err_dev_probed_fail;
+ }
+
+ /* all is fine... */
+ cape_dev->driver = drv;
+ cape_dev->added = 1;
+
+ return 0;
+
+err_dev_probed_fail:
+ if (drv->remove) {
+ pm_runtime_get_sync(&cape_dev->dev);
+ drv->remove(cape_dev);
+ pm_runtime_put_noidle(&cape_dev->dev);
+ }
+err_probe_fail:
+ pm_runtime_disable(&cape_dev->dev);
+ pm_runtime_set_suspended(&cape_dev->dev);
+ pm_runtime_put_noidle(&cape_dev->dev);
+err_no_match:
+ /* nothing */
+err_no_sanity:
+ capebus_dev_put(cape_dev);
+ return error;
+}
+
+static int capebus_device_remove(struct device *dev)
+{
+ struct cape_dev *cape_dev = to_cape_dev(dev);
+ struct cape_driver *drv = cape_dev->driver;
+
+ if (drv) {
+ /* call the removed bus method (if added prev.) */
+ if (cape_dev->added) {
+ BUG_ON(cape_dev->bus == NULL);
+ BUG_ON(cape_dev->bus->ops == NULL);
+ if (cape_dev->bus->ops->dev_removed)
+ cape_dev->bus->ops->dev_removed(cape_dev);
+ cape_dev->added = 0;
+ }
+ if (drv->remove) {
+ pm_runtime_get_sync(dev);
+ drv->remove(cape_dev);
+ pm_runtime_put_noidle(dev);
+ }
+ cape_dev->driver = NULL;
+ }
+
+ /* Undo the runtime PM settings in local_capebus_probe() */
+ pm_runtime_disable(dev);
+ pm_runtime_set_suspended(dev);
+ pm_runtime_put_noidle(dev);
+
+ capebus_dev_put(cape_dev);
+ return 0;
+}
+
+static void capebus_device_shutdown(struct device *dev)
+{
+ struct cape_dev *cape_dev = to_cape_dev(dev);
+ struct cape_driver *drv = cape_dev->driver;
+
+ if (drv && drv->shutdown)
+ drv->shutdown(cape_dev);
+
+ capebus_disable_device(cape_dev);
+
+ if (!device_may_wakeup(dev))
+ capebus_enable_wake(cape_dev, false);
+}
+
+static int capebus_bus_match(struct device *dev, struct device_driver *drv);
+static int capebus_device_probe(struct device *dev);
+static int capebus_device_remove(struct device *dev);
+static void capebus_device_shutdown(struct device *dev);
+
+struct bus_type capebus_bus_type = {
+ .name = "capebus",
+ .match = capebus_bus_match,
+ .probe = capebus_device_probe,
+ .remove = capebus_device_remove,
+ .shutdown = capebus_device_shutdown,
+ .dev_attrs = capebus_dev_attrs,
+ .bus_attrs = capebus_bus_attrs,
+ .pm = NULL, /* No PM for now */
+};
+EXPORT_SYMBOL(capebus_bus_type);
+
+/**
+ * __capebus_register_driver - register a new capebus driver
+ * @drv: the driver structure to register
+ * @owner: owner module of drv
+ * @mod_name: module name string
+ *
+ * Adds the driver structure to the list of registered drivers.
+ * Returns a negative value on error, otherwise 0.
+ * If no error occurred, the driver remains registered even if
+ * no device was claimed during registration.
+ */
+int __capebus_register_driver(struct cape_driver *drv, struct module *owner,
+ const char *mod_name)
+{
+ /* initialize common driver fields */
+ drv->driver.bus = &capebus_bus_type;
+ drv->driver.owner = owner;
+ drv->driver.mod_name = mod_name;
+
+ /* register with core */
+ return driver_register(&drv->driver);
+}
+EXPORT_SYMBOL(__capebus_register_driver);
+
+/**
+ * capebus_unregister_driver - unregister a capebus driver
+ * @drv: the driver structure to unregister
+ *
+ * Deletes the driver structure from the list of registered cape drivers,
+ * gives it a chance to clean up by calling its remove() function for
+ * each device it was responsible for, and marks those devices as
+ * driverless.
+ */
+
+void
+capebus_unregister_driver(struct cape_driver *drv)
+{
+ /* TODO: not really working properly */
+ driver_unregister(&drv->driver);
+}
+EXPORT_SYMBOL(capebus_unregister_driver);
+
+/**
+ * capebus_bus_match - Tell if a cape device structure has a matching
+ * cape device id structure
+ * @dev: the cape device structure to match against
+ * @drv: the device driver to search for matching cape device id structures
+ *
+ * Used by a driver to check whether a cape device present in the
+ * system is in its list of supported devices. Returns the matching
+ * cape_device_id structure or %NULL if there is no match.
+ */
+static int capebus_bus_match(struct device *dev, struct device_driver *drv)
+{
+ struct cape_dev *cape_dev = to_cape_dev(dev);
+ struct cape_driver *cape_drv = to_cape_driver(drv);
+ const struct cape_device_id *found_id;
+
+ found_id = capebus_match_device(cape_drv, cape_dev);
+ if (found_id)
+ return 1;
+
+ return 0;
+}
+
+/**
+ * capebus_dev_get - increments the reference count of the capebus
+ * device structure
+ * @dev: the device being referenced
+ *
+ * Each live reference to a device should be refcounted.
+ *
+ * Drivers for cape devices should normally record such references in
+ * their probe() methods, when they bind to a device, and release
+ * them by calling capebus_dev_put(), in their disconnect() methods.
+ *
+ * A pointer to the device with the incremented reference counter is returned.
+ */
+struct cape_dev *capebus_dev_get(struct cape_dev *dev)
+{
+ if (dev)
+ get_device(&dev->dev);
+ return dev;
+}
+EXPORT_SYMBOL(capebus_dev_get);
+
+/**
+ * capebus_dev_put - release a use of the capebus device structure
+ * @dev: device that's been disconnected
+ *
+ * Must be called when a user of a device is finished with it. When the last
+ * user of the device calls this function, the memory of the device is freed.
+ */
+void capebus_dev_put(struct cape_dev *dev)
+{
+ if (dev)
+ put_device(&dev->dev);
+}
+EXPORT_SYMBOL(capebus_dev_put);
+
+static int __init capebus_driver_init(void)
+{
+ return bus_register(&capebus_bus_type);
+}
+
+postcore_initcall(capebus_driver_init);
+
+const struct of_device_id *
+capebus_of_match_device(struct cape_dev *cdev,
+ const char *property, const char *value)
+{
+ struct cape_bus *bus = cdev->bus;
+ struct device *dev = &cdev->dev;
+ struct device_node *pnode = cape_bus_to_parent_of_node(bus);
+ struct device_node *node;
+ const struct of_device_id *match;
+ const char* cp;
+ int cplen, l;
+
+ dev_dbg(dev, "Iterating on parent of node "
+ "name='%s' type='%s' full_name='%s'\n",
+ pnode->name, pnode->type, pnode->full_name);
+
+ match = NULL;
+ for_each_child_of_node(pnode, node) {
+
+ dev->of_node = node;
+ match = of_match_device(dev->driver->of_match_table, dev);
+ if (!match)
+ goto next_node;
+
+ cp = of_get_property(node, property, &cplen);
+ if (cp == NULL)
+ goto next_node;
+
+ while (cplen > 0) {
+ if (of_compat_cmp(cp, value, strlen(value)) == 0)
+ break;
+ l = strlen(cp) + 1;
+ cp += l;
+ cplen -= l;
+ }
+
+ /* matched */
+ if (cplen > 0)
+ break;
+next_node:
+ match = NULL;
+ dev->of_node = NULL;
+ }
+
+ if (match == NULL) {
+ dev_dbg(dev, "Failed to find matching child-node\n");
+ return NULL;
+ }
+
+ dev_dbg(dev, "Found matching child node "
+ "name='%s' type='%s' "
+ "full_name='%s' (compatible='%s')\n",
+ node->name, node->type, node->full_name,
+ match->compatible);
+
+ return match;
+}
+EXPORT_SYMBOL(capebus_of_match_device);
+
+struct device_node *
+capebus_of_compatible_device_property_match(struct cape_dev *dev,
+ const struct of_device_id *matches,
+ const char *prop, const char *prop_value)
+{
+ const struct of_device_id *match;
+ struct device_node *node, *cnode;
+ const char* cp;
+ int cplen, l;
+
+ if (prop == NULL || prop_value == NULL)
+ goto try_non_property;
+
+ /* at first try secondary match */
+ for_each_child_of_node(dev->dev.of_node, node) {
+
+ cp = of_get_property(node, prop, &cplen);
+ if (cp == NULL)
+ continue;
+
+ while (cplen > 0) {
+ if (of_compat_cmp(cp, prop_value,
+ strlen(prop_value)) == 0)
+ break;
+ l = strlen(cp) + 1;
+ cp += l;
+ cplen -= l;
+ }
+
+ /* not matched */
+ if (cplen <= 0)
+ continue;
+
+ /* now iterate in the children nodes */
+ for_each_child_of_node(node, cnode) {
+
+ match = of_match_node(matches, cnode);
+ if (match) {
+ /* release reference to parent, keep this one */
+ of_node_put(node);
+ return cnode;
+ }
+ }
+ }
+
+try_non_property:
+ for_each_child_of_node(dev->dev.of_node, node) {
+
+ match = of_match_node(matches, node);
+ if (match)
+ return node;
+ }
+
+ return NULL;
+}
+EXPORT_SYMBOL(capebus_of_compatible_device_property_match);
+
+struct platform_device *
+capebus_of_platform_compatible_device_create(struct cape_dev *dev,
+ const struct of_device_id *matches,
+ const char *pdev_name,
+ const char *prop, const char *prop_value)
+{
+ struct device_node *node;
+ struct platform_device *pdev;
+
+ node = capebus_of_compatible_device_property_match(dev, matches, prop,
+ prop_value);
+ if (node == NULL)
+ return ERR_PTR(-ENXIO);
+
+ pdev = of_platform_device_create(node, pdev_name, dev->bus->dev.parent);
+
+ /* release the reference to the node */
+ of_node_put(node);
+ node = NULL;
+
+ if (pdev == NULL) {
+ dev_err(&dev->dev, "Failed to create platform device '%s'\n",
+ pdev_name);
+ return ERR_PTR(-ENODEV);
+ }
+
+ return pdev;
+}
+EXPORT_SYMBOL(capebus_of_platform_compatible_device_create);
+
+struct device_node *
+capebus_of_find_property_node(struct cape_dev *dev,
+ const char *prop, const char *prop_value,
+ const char *name)
+{
+ struct device_node *node;
+ const char* cp;
+ int cplen, l;
+ struct property *pp;
+
+ node = NULL;
+ if (prop == NULL || prop_value == NULL)
+ goto find_direct;
+
+ /* at first try secondary match */
+ for_each_child_of_node(dev->dev.of_node, node) {
+
+ cp = of_get_property(node, prop, &cplen);
+ if (cp == NULL)
+ continue;
+
+ while (cplen > 0) {
+ if (of_compat_cmp(cp, prop_value,
+ strlen(prop_value)) == 0)
+ break;
+ l = strlen(cp) + 1;
+ cp += l;
+ cplen -= l;
+ }
+
+ /* not matched */
+ if (cplen <= 0)
+ continue;
+
+ /* found ? */
+ pp = of_find_property(node, name, NULL);
+ if (pp != NULL)
+ return node;
+ }
+find_direct:
+ pp = of_find_property(dev->dev.of_node, name, NULL);
+ if (pp == NULL)
+ return NULL;
+
+ return of_node_get(dev->dev.of_node);
+}
+EXPORT_SYMBOL_GPL(capebus_of_find_property_node);
+
+struct property *
+capebus_of_find_property(struct cape_dev *dev,
+ const char *prop, const char *prop_value,
+ const char *name, int *lenp)
+{
+ struct device_node *node;
+ struct property *pp;
+
+ node = capebus_of_find_property_node(dev, prop, prop_value, name);
+ if (node == NULL)
+ return NULL;
+
+ pp = of_find_property(node, name, lenp);
+
+ of_node_put(node);
+
+ return pp;
+}
+EXPORT_SYMBOL_GPL(capebus_of_find_property);
+
+const void *capebus_of_get_property(struct cape_dev *dev,
+ const char *prop, const char *prop_value,
+ const char *name, int *lenp)
+{
+ struct property *pp;
+
+ pp = capebus_of_find_property(dev, prop, prop_value, name, lenp);
+ return pp ? pp->value : NULL;
+}
+EXPORT_SYMBOL_GPL(capebus_of_get_property);
+
+/* node exists, but it's not available? make it so */
+int capebus_of_device_node_enable(struct device_node *node)
+{
+ struct property *prop;
+ int ret;
+
+ prop = kzalloc(sizeof(*prop), GFP_KERNEL);
+ if (prop == NULL)
+ goto err_no_prop_mem;
+
+ prop->name = kstrdup("status", GFP_KERNEL);
+ if (prop->name == NULL)
+ goto err_no_name_mem;
+
+ prop->value = kstrdup("okay", GFP_KERNEL);
+ if (prop->value == NULL)
+ goto err_no_value_mem;
+
+ prop->length = strlen(prop->value) + 1;
+ set_bit(OF_DYNAMIC, &prop->_flags);
+
+ ret = prom_update_property(node, prop);
+ if (ret != 0)
+ goto err_update_failed;
+
+ return 0;
+
+err_update_failed:
+ kfree(prop->value);
+err_no_value_mem:
+ kfree(prop->name);
+err_no_name_mem:
+ kfree(prop);
+err_no_prop_mem:
+ return -ENOMEM;
+}
+EXPORT_SYMBOL_GPL(capebus_of_device_node_enable);
+
+/* Make sure this node is activated (even if it was disabled) */
+int capebus_of_platform_device_enable(struct device_node *node)
+{
+ struct platform_device *pdev, *ppdev;
+ int ret;
+
+ if (of_device_is_available(node))
+ return 0;
+
+ ret = capebus_of_device_node_enable(node);
+ if (ret != 0)
+ return ret;
+
+ /* now we need to find the parent of the node */
+ ppdev = of_find_device_by_node(node->parent);
+
+ pdev = of_platform_device_create(node, NULL,
+ ppdev ? &ppdev->dev : NULL);
+ if (IS_ERR_OR_NULL(pdev)) {
+ ret = pdev ? PTR_ERR(pdev) : -ENODEV;
+ return ret;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(capebus_of_platform_device_enable);
diff --git a/drivers/capebus/capebus-probe.c b/drivers/capebus/capebus-probe.c
new file mode 100644
index 0000000..b46e915
--- /dev/null
+++ b/drivers/capebus/capebus-probe.c
@@ -0,0 +1,320 @@
+/*
+ * Capebus bus infrastructure
+ *
+ * Copyright (C) 2012 Pantelis Antoniou <panto at antoniou-consulting.com>
+ * Copyright (C) 2012 Texas Instruments Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/module.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_i2c.h>
+#include <linux/of_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/err.h>
+#include <linux/list.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+
+#include <linux/capebus.h>
+
+LIST_HEAD(cape_buses);
+EXPORT_SYMBOL(cape_buses);
+
+DEFINE_MUTEX(cape_buses_mutex);
+EXPORT_SYMBOL(cape_buses_mutex);
+
+/*
+ * Cape Bus Class
+ */
+static void release_capebus_dev(struct device *dev)
+{
+ struct cape_dev *cape_dev = to_cape_dev(dev);
+
+ kfree(cape_dev);
+}
+
+static struct class capebus_class = {
+ .name = "capebus",
+ .dev_release = &release_capebus_dev,
+};
+
+static int __init capebus_class_init(void)
+{
+ return class_register(&capebus_class);
+}
+postcore_initcall(capebus_class_init);
+
+static struct cape_bus *cape_bus_find(const char *name, int busno)
+{
+ struct cape_bus *bus;
+ int found;
+
+ if (busno < 0)
+ return NULL;
+
+ found = 0;
+ cape_bus_for_each(bus) {
+ if (strcmp(name, bus->name) == 0 && bus->busno == busno) {
+ found = 1;
+ break;
+ }
+ }
+ return found ? bus : NULL;
+}
+
+static int cape_bus_pick_busno(const char *name, int busno)
+{
+ struct cape_bus *bus;
+
+ BUG_ON(name == NULL);
+
+ /* fixed id */
+ if (busno >= 0)
+ return busno;
+
+ /* dynamic id */
+ busno = -1;
+ cape_bus_for_each(bus) {
+ /* name must match */
+ if (strcmp(name, bus->name) != 0)
+ continue;
+ busno = max(busno, bus->busno);
+ }
+ return busno + 1;
+}
+
+int cape_bus_register(struct cape_bus *bus, const char *name, int busno,
+ struct device *parent, struct cape_bus_ops *ops)
+{
+ struct cape_bus *b2;
+ int r;
+
+ if (name == NULL)
+ return -EINVAL;
+
+ INIT_LIST_HEAD(&bus->node);
+ INIT_LIST_HEAD(&bus->devices);
+ INIT_LIST_HEAD(&bus->slots);
+
+ /* do everything under lock */
+ mutex_lock(&cape_buses_mutex);
+
+ b2 = cape_bus_find(name, busno);
+ if (b2 != NULL) {
+ if (parent != NULL)
+ dev_err(parent, "capebus %s:%d in use\n", name, busno);
+ else
+ pr_err("capebus %s:%d in use\n", name, busno);
+ r = -EBUSY;
+ goto err_unlock;
+ }
+ bus->name = name;
+ bus->busno = cape_bus_pick_busno(name, busno);
+ bus->ops = ops;
+
+ bus->dev.class = &capebus_class;
+ bus->dev.parent = parent;
+ dev_set_name(&bus->dev, "%s:%d", bus->name, bus->busno);
+ r = device_register(&bus->dev);
+ if (r != 0) {
+ if (parent != NULL)
+ dev_err(parent, "capebus #%d failed to register dev\n",
+ bus->busno);
+ else
+ pr_err("capebus #%d failed to register dev\n",
+ bus->busno);
+ goto err_unlock;
+ }
+
+ list_add_tail(&bus->node, &cape_buses);
+ mutex_unlock(&cape_buses_mutex);
+
+ dev_info(&bus->dev, "Registered\n");
+
+ return 0;
+err_unlock:
+ mutex_unlock(&cape_buses_mutex);
+ return r;
+}
+
+int cape_bus_deregister(struct cape_bus *bus)
+{
+ return -EINVAL; /* not yet supported */
+}
+
+/* must have cape_buses_mutex */
+struct cape_slot *cape_slot_find(struct cape_bus *bus, int slotno)
+{
+ struct cape_slot *slot;
+ int found;
+
+ found = 0;
+ cape_slot_for_each(bus, slot) {
+ if (slot->slotno == slotno) {
+ found = 1;
+ break;
+ }
+ }
+ return found ? slot : NULL;
+}
+
+/**
+ * cape_bus_release_dev - free a cape device structure when all users
+ * of it are finished.
+ * @dev: device that's been disconnected
+ *
+ * Will be called only by the device core when all users of this cape device are
+ * done.
+ */
+static void cape_bus_release_dev(struct device *dev)
+{
+ struct cape_dev *cdev;
+
+ cdev = to_cape_dev(dev);
+ /* cape_release_capabilities(cdev); TODO */
+ /* cape_release_of_node(cdev); TODO */
+ kfree(cdev);
+}
+
+/* mutex lock must be held */
+static struct cape_dev *cape_bus_scan_slot(struct cape_slot *slot)
+{
+ struct cape_bus *bus = slot->bus;
+ struct cape_dev *dev;
+ const struct cape_device_id *id;
+
+ /* get the ID (if a device exists) */
+ id = bus->ops->get_dev_id(slot);
+ if (id == NULL)
+ return ERR_PTR(-ENODEV);
+
+ /* slot must not have a device yet */
+ dev = slot->dev;
+ if (dev == NULL) {
+ dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+ if (dev == NULL) {
+ dev_info(&bus->dev, "Failed to allocate cape device "
+ "for slot #%d\n", slot->slotno);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ INIT_LIST_HEAD(&dev->bus_list);
+ dev->bus = bus;
+ dev->slot = slot;
+ }
+
+ dev->id = id;
+ dev->text_id = bus->ops->get_text_dev_id(slot);
+
+ /* capebus_set_of_node(dev); TODO */
+
+ return dev;
+}
+
+int cape_bus_scan_one_slot(struct cape_bus *bus, struct cape_slot *slot)
+{
+ struct cape_dev *dev;
+ int r;
+
+ mutex_lock(&cape_buses_mutex);
+
+ dev = slot->dev;
+ if (dev == NULL) {
+
+ dev = cape_bus_scan_slot(slot);
+ if (IS_ERR(dev)) {
+ r = PTR_ERR(dev);
+ goto err_out;
+ }
+
+ dev_info(&bus->dev, "Slot #%d id='%s'\n", slot->slotno,
+ dev->text_id ? dev->text_id : "");
+
+ slot->dev = dev;
+
+ dev->dev.release = cape_bus_release_dev;
+ dev->dev.parent = &dev->bus->dev;
+ dev->dev.bus = &capebus_bus_type;
+ dev_set_name(&dev->dev, "%s-%d:%d",
+ dev->bus->name, dev->bus->busno,
+ dev->slot->slotno);
+
+ list_add_tail(&dev->bus_list, &bus->devices);
+
+ } else {
+ dev_info(&bus->dev, "Slot #%d id='%s' - rescan\n", slot->slotno,
+ dev->text_id ? dev->text_id : "");
+
+ if (dev->added) {
+ r = -EEXIST;
+ goto err_out;
+ }
+ }
+
+ r = device_register(&dev->dev);
+ if (r != 0) {
+ dev_info(&bus->dev, "Slot #%d id='%s' - "
+ "Failed to register\n",
+ slot->slotno,
+ dev->text_id ? dev->text_id : "");
+ r = 0;
+ } else {
+ if (dev->bus->ops->dev_registered)
+ dev->bus->ops->dev_registered(dev);
+ }
+
+err_out:
+ mutex_unlock(&cape_buses_mutex);
+
+ return r;
+}
+
+int cape_bus_register_slot(struct cape_bus *bus, struct cape_slot *slot,
+ int slotno)
+{
+ struct cape_slot *s2;
+ int r;
+
+ r = 0;
+
+ /* invalid (slot must always be numbered - no hotplug) */
+ if (slotno < 0) {
+ dev_err(&bus->dev, "Slot registration #%d failed\n", slotno);
+ return -EINVAL;
+ }
+
+ mutex_lock(&cape_buses_mutex);
+ s2 = cape_slot_find(bus, slotno);
+ if (s2 != NULL) {
+ dev_err(&bus->dev, "Slot #%d already exists\n", slotno);
+ mutex_unlock(&cape_buses_mutex);
+ return -EINVAL;
+ }
+
+ INIT_LIST_HEAD(&slot->node);
+ slot->bus = bus;
+ list_add(&slot->node, &bus->slots);
+ slot->slotno = slotno;
+ slot->dev = NULL;
+ mutex_unlock(&cape_buses_mutex);
+
+ dev_info(&bus->dev, "Slot #%d registered\n", slot->slotno);
+
+ return cape_bus_scan_one_slot(bus, slot);
+}
diff --git a/drivers/capebus/capebus-sysfs.c b/drivers/capebus/capebus-sysfs.c
new file mode 100644
index 0000000..81c21fe
--- /dev/null
+++ b/drivers/capebus/capebus-sysfs.c
@@ -0,0 +1,52 @@
+/*
+ * drivers/capebus/capebus-sysfs.c
+ *
+ * sysfs for capebus devices
+ *
+ * Copyright (C) 2012 Pantelis Antoniou <panto at antoniou-consulting.com>
+ * Copyright (C) 2012 Texas Instruments Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ * Modeled after PCI's pci-sysfs.c
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/stat.h>
+#include <linux/export.h>
+#include <linux/fs.h>
+#include <linux/slab.h>
+#include <linux/pm_runtime.h>
+
+#include <linux/capebus.h>
+
+static ssize_t id_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct cape_dev *cdev;
+
+ cdev = to_cape_dev(dev);
+ return sprintf(buf, "%s\n", cdev->text_id);
+}
+
+struct device_attribute capebus_dev_attrs[] = {
+ __ATTR_RO(id),
+ __ATTR_NULL,
+};
+
+struct bus_attribute capebus_bus_attrs[] = {
+ __ATTR_NULL
+};
diff --git a/include/linux/capebus.h b/include/linux/capebus.h
new file mode 100644
index 0000000..7524401
--- /dev/null
+++ b/include/linux/capebus.h
@@ -0,0 +1,298 @@
+/*
+ * capebus.h
+ *
+ * Cape bus defines and function prototypes
+ *
+ * Copyright (C) 2012 Pantelis Antoniou <panto at antoniou-consulting.com>
+ * Copyright (C) 2012 Texas Instruments Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+#ifndef LINUX_CAPEBUS_H
+#define LINUX_CAPEBUS_H
+
+#include <linux/list.h>
+#include <linux/device.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+#include <linux/atomic.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+
+struct cape_device_id {
+ const char *cntrlboard; /* controlling board; i.e. "beaglebone" */
+ int len; /* opaque addressing data */
+ const void *data;
+};
+
+struct cape_dev;
+struct cape_bus;
+struct cape_slot;
+
+struct cape_slot {
+ struct list_head node;
+ struct cape_bus *bus; /* the bus this slot is on */
+ int slotno; /* index of this slot */
+ struct cape_dev *dev; /* the device (if found) */
+};
+
+struct cape_driver {
+ struct list_head node;
+ int (*probe)(struct cape_dev *dev, const struct cape_device_id *id);
+ void (*remove)(struct cape_dev *dev);
+ int (*suspend) (struct cape_dev *dev, pm_message_t state);
+ int (*suspend_late) (struct cape_dev *dev, pm_message_t state);
+ int (*resume_early) (struct cape_dev *dev);
+ int (*resume) (struct cape_dev *dev);
+ void (*shutdown) (struct cape_dev *dev);
+ struct device_driver driver;
+};
+
+/*
+ * capebus_register_driver must be a macro so that
+ * KBUILD_MODNAME can be expanded
+ */
+#define capebus_register_driver(driver) \
+ __capebus_register_driver(driver, THIS_MODULE, KBUILD_MODNAME)
+
+int __capebus_register_driver(struct cape_driver *drv, struct module *owner,
+ const char *mod_name);
+
+void capebus_unregister_driver(struct cape_driver *dev);
+
+/**
+ * module_capebus_driver() - Helper macro for registering a capebus driver
+ * @__capebus_driver: capebus_driver struct
+ *
+ * Helper macro for capebus drivers which do not do anything special in module
+ * init/exit. This eliminates a lot of boilerplate. Each module may only
+ * use this macro once, and calling it replaces module_init() and module_exit()
+ */
+#define module_capebus_driver(__capebus_driver) \
+ module_driver(__capebus_driver, capebus_register_driver, \
+ capebus_unregister_driver)
+
+#define to_cape_driver(n) container_of(n, struct cape_driver, driver)
+
+struct cape_bus_ops {
+ const struct cape_device_id *(*get_dev_id)(struct cape_slot *slot);
+ const char *(*get_text_dev_id)(struct cape_slot *slot);
+ int (*dev_probed)(struct cape_dev *dev); /* probed succesfully */
+ void (*dev_removed)(struct cape_dev *dev); /* removed */
+ int (*dev_registered)(struct cape_dev *dev); /* registered OK */
+};
+
+struct cape_bus {
+ struct list_head node;
+ const char *name;
+ struct list_head devices;
+ struct cape_dev *self;
+ struct list_head slots;
+ struct cape_bus_ops *ops;
+ int busno;
+ struct device dev;
+ /* TODO: resources.... */
+};
+
+#define to_cape_bus(n) container_of(n, struct cape_bus, dev)
+
+#define cape_bus_to_parent_of_node(n) ((n)->dev.parent->of_node)
+
+struct cape_dev {
+ struct list_head bus_list; /* node in per-bus list */
+ struct cape_bus *bus; /* bus this device is on */
+ struct cape_slot *slot; /* cape slot of this device */
+ struct cape_driver *driver; /* driver of this device */
+ struct device dev;
+ atomic_t enable_cnt; /* capebus_enable_device */
+ /* has been called */
+ const struct cape_device_id *id;
+ const char *text_id;
+ unsigned int added : 1; /* device has been added */
+ void *drv_priv; /* driver private data */
+};
+
+#define to_cape_dev(n) container_of(n, struct cape_dev, dev)
+
+struct cape_dev *capebus_dev_get(struct cape_dev *dev);
+void capebus_dev_put(struct cape_dev *dev);
+
+/* must have cape_buses_mutex */
+#define cape_bus_for_each(_bus) \
+ list_for_each_entry(_bus, &cape_buses, node)
+
+#define cape_bus_for_each_safe(_bus, _busn) \
+ list_for_each_entry_safe(_bus, _busn, &cape_buses, node)
+
+int cape_bus_register(struct cape_bus *bus, const char *name, int busno,
+ struct device *parent, struct cape_bus_ops *ops);
+
+/* must have cape_buses_mutex */
+#define cape_slot_for_each(_bus, _slot) \
+ list_for_each_entry(_slot, &(_bus)->slots, node)
+
+#define cape_slot_for_each_safe(_bus, _slot, _slotn) \
+ list_for_each_entry_safe(_slot, _slotn, &(_bus)->slots, node)
+
+int cape_bus_register_slot(struct cape_bus *bus,
+ struct cape_slot *slot, int slotno);
+
+int cape_bus_scan_one_slot(struct cape_bus *bus, struct cape_slot *slot);
+int cape_bus_scan(struct cape_bus *bus);
+
+extern struct list_head cape_buses;
+extern struct mutex cape_buses_mutex;
+
+static inline int capebus_is_enabled(struct cape_dev *cdev)
+{
+ return atomic_read(&cdev->enable_cnt) > 0;
+}
+
+static inline int capebus_enable_device(struct cape_dev *cdev)
+{
+ if (atomic_add_return(1, &cdev->enable_cnt) > 1)
+ return 0; /* already enabled */
+
+ /* XXX do enable */
+
+ return 0;
+}
+
+static inline void capebus_disable_device(struct cape_dev *cdev)
+{
+ if (atomic_sub_return(1, &cdev->enable_cnt) != 0)
+ return;
+
+ /* callback to disable device? */
+}
+
+static inline int capebus_enable_wake(struct cape_dev *dev, int what)
+{
+ return 0;
+}
+
+extern struct device_attribute capebus_dev_attrs[];
+extern struct bus_attribute capebus_bus_attrs[];
+
+extern struct bus_type capebus_bus_type;
+
+const struct of_device_id *
+capebus_of_match_device(struct cape_dev *cdev,
+ const char *property, const char *value);
+
+struct device_node *
+capebus_of_compatible_device_property_match(struct cape_dev *dev,
+ const struct of_device_id *matches,
+ const char *prop, const char *prop_value);
+
+struct platform_device *
+capebus_of_platform_compatible_device_create(struct cape_dev *dev,
+ const struct of_device_id *matches,
+ const char *pdev_name,
+ const char *prop, const char *prop_value);
+
+/* of tree support */
+
+struct device_node *
+capebus_of_find_property_node(struct cape_dev *dev,
+ const char *prop, const char *prop_value,
+ const char *name);
+
+struct property *
+capebus_of_find_property(struct cape_dev *dev,
+ const char *prop, const char *prop_value,
+ const char *name, int *lenp);
+
+const void *capebus_of_get_property(struct cape_dev *dev,
+ const char *prop, const char *prop_value,
+ const char *name, int *lenp);
+
+static inline int capebus_of_property_read_u32_array(struct cape_dev *dev,
+ const char *prop, const char *prop_value,
+ const char *name, u32 *out_values, size_t sz)
+{
+ struct device_node *node;
+ int ret;
+
+ node = capebus_of_find_property_node(dev, prop, prop_value, name);
+ ret = of_property_read_u32_array(node, name, out_values, sz);
+ of_node_put(node);
+ return ret;
+}
+
+static inline int capebus_of_property_read_u32(struct cape_dev *dev,
+ const char *prop, const char *prop_value,
+ const char *name, u32 *out_value)
+{
+ return capebus_of_property_read_u32_array(dev, prop,
+ prop_value, name, out_value, 1);
+}
+
+static inline bool capebus_of_property_read_bool(struct cape_dev *dev,
+ const char *prop, const char *prop_value,
+ const char *name)
+{
+ struct device_node *node;
+ bool ret;
+
+ node = capebus_of_find_property_node(dev, prop, prop_value, name);
+ ret = of_property_read_bool(node, name);
+ of_node_put(node);
+ return ret;
+}
+
+static inline int capebus_of_property_read_string(struct cape_dev *dev,
+ const char *prop, const char *prop_value,
+ const char *name, const char **out_string)
+{
+ struct device_node *node;
+ int ret;
+
+ node = capebus_of_find_property_node(dev, prop, prop_value, name);
+ ret = of_property_read_string(node, name, out_string);
+ of_node_put(node);
+ return ret;
+}
+
+static inline int capebus_of_property_read_string_index(struct cape_dev *dev,
+ const char *prop, const char *prop_value,
+ const char *name, int index, const char **out_string)
+{
+ struct device_node *node;
+ int ret;
+
+ node = capebus_of_find_property_node(dev, prop, prop_value, name);
+ ret = of_property_read_string_index(node, name, index, out_string);
+ of_node_put(node);
+ return ret;
+}
+
+static inline int capebus_of_property_read_u64(struct cape_dev *dev,
+ const char *prop, const char *prop_value,
+ const char *name, u64 *out_value)
+{
+ struct device_node *node;
+ int ret;
+
+ node = capebus_of_find_property_node(dev, prop, prop_value, name);
+ ret = of_property_read_u64(node, name, out_value);
+ of_node_put(node);
+ return ret;
+}
+
+int capebus_of_device_node_enable(struct device_node *node);
+int capebus_of_platform_device_enable(struct device_node *node);
+
+#endif
--
1.7.12
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