diff options
| -rw-r--r-- | drivers/Makefile | 2 | ||||
| -rw-r--r-- | drivers/i2c/Kconfig | 5 | ||||
| -rw-r--r-- | drivers/i2c/Makefile | 1 | ||||
| -rw-r--r-- | drivers/i2c/i2c-boardinfo.c | 90 | ||||
| -rw-r--r-- | drivers/i2c/i2c-core.c | 90 | ||||
| -rw-r--r-- | drivers/i2c/i2c-core.h | 31 | ||||
| -rw-r--r-- | include/linux/i2c.h | 62 |
7 files changed, 276 insertions, 5 deletions
diff --git a/drivers/Makefile b/drivers/Makefile index 920c975..26ca903 100644 --- a/drivers/Makefile +++ b/drivers/Makefile @@ -58,7 +58,7 @@ obj-$(CONFIG_GAMEPORT) += input/gameport/ obj-$(CONFIG_INPUT) += input/ obj-$(CONFIG_I2O) += message/ obj-$(CONFIG_RTC_LIB) += rtc/ -obj-$(CONFIG_I2C) += i2c/ +obj-y += i2c/ obj-$(CONFIG_W1) += w1/ obj-$(CONFIG_HWMON) += hwmon/ obj-$(CONFIG_PHONE) += telephony/ diff --git a/drivers/i2c/Kconfig b/drivers/i2c/Kconfig index 11935f6..74c8518 100644 --- a/drivers/i2c/Kconfig +++ b/drivers/i2c/Kconfig @@ -22,6 +22,11 @@ config I2C This I2C support can also be built as a module. If so, the module will be called i2c-core. +config I2C_BOARDINFO + boolean + depends on I2C + default y + config I2C_CHARDEV tristate "I2C device interface" depends on I2C diff --git a/drivers/i2c/Makefile b/drivers/i2c/Makefile index 71c5a85..ba26e6c 100644 --- a/drivers/i2c/Makefile +++ b/drivers/i2c/Makefile @@ -2,6 +2,7 @@ # Makefile for the i2c core. # +obj-$(CONFIG_I2C_BOARDINFO) += i2c-boardinfo.o obj-$(CONFIG_I2C) += i2c-core.o obj-$(CONFIG_I2C_CHARDEV) += i2c-dev.o obj-y += busses/ chips/ algos/ diff --git a/drivers/i2c/i2c-boardinfo.c b/drivers/i2c/i2c-boardinfo.c new file mode 100644 index 0000000..ffb35f0 --- /dev/null +++ b/drivers/i2c/i2c-boardinfo.c @@ -0,0 +1,90 @@ +/* + * i2c-boardinfo.h - collect pre-declarations of I2C devices + * + * 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/kernel.h> +#include <linux/i2c.h> + +#include "i2c-core.h" + + +/* These symbols are exported ONLY FOR the i2c core. + * No other users will be supported. + */ +DEFINE_MUTEX(__i2c_board_lock); +EXPORT_SYMBOL_GPL(__i2c_board_lock); + +LIST_HEAD(__i2c_board_list); +EXPORT_SYMBOL_GPL(__i2c_board_list); + +int __i2c_first_dynamic_bus_num; +EXPORT_SYMBOL_GPL(__i2c_first_dynamic_bus_num); + + +/** + * i2c_register_board_info - statically declare I2C devices + * @busnum: identifies the bus to which these devices belong + * @info: vector of i2c device descriptors + * @len: how many descriptors in the vector; may be zero to reserve + * the specified bus number. + * + * Systems using the Linux I2C driver stack can declare tables of board info + * while they initialize. This should be done in board-specific init code + * near arch_initcall() time, or equivalent, before any I2C adapter driver is + * registered. For example, mainboard init code could define several devices, + * as could the init code for each daughtercard in a board stack. + * + * The I2C devices will be created later, after the adapter for the relevant + * bus has been registered. After that moment, standard driver model tools + * are used to bind "new style" I2C drivers to the devices. The bus number + * for any device declared using this routine is not available for dynamic + * allocation. + * + * The board info passed can safely be __initdata, but be careful of embedded + * pointers (for platform_data, functions, etc) since that won't be copied. + */ +int __init +i2c_register_board_info(int busnum, + struct i2c_board_info const *info, unsigned len) +{ + int status; + + mutex_lock(&__i2c_board_lock); + + /* dynamic bus numbers will be assigned after the last static one */ + if (busnum >= __i2c_first_dynamic_bus_num) + __i2c_first_dynamic_bus_num = busnum + 1; + + for (status = 0; len; len--, info++) { + struct i2c_devinfo *devinfo; + + devinfo = kzalloc(sizeof(*devinfo), GFP_KERNEL); + if (!devinfo) { + pr_debug("i2c-core: can't register boardinfo!\n"); + status = -ENOMEM; + break; + } + + devinfo->busnum = busnum; + devinfo->board_info = *info; + list_add_tail(&devinfo->list, &__i2c_board_list); + } + + mutex_unlock(&__i2c_board_lock); + + return status; +} diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index 3aac1b5..a7dcdc6 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -35,6 +35,8 @@ #include <linux/completion.h> #include <asm/uaccess.h> +#include "i2c-core.h" + static LIST_HEAD(adapters); static LIST_HEAD(drivers); @@ -162,6 +164,11 @@ static void i2c_client_release(struct device *dev) complete(&client->released); } +static void i2c_client_dev_release(struct device *dev) +{ + kfree(to_i2c_client(dev)); +} + static ssize_t show_client_name(struct device *dev, struct device_attribute *attr, char *buf) { struct i2c_client *client = to_i2c_client(dev); @@ -195,7 +202,60 @@ struct bus_type i2c_bus_type = { .resume = i2c_device_resume, }; -static void i2c_unregister_device(struct i2c_client *client) +/** + * i2c_new_device - instantiate an i2c device for use with a new style driver + * @adap: the adapter managing the device + * @info: describes one I2C device; bus_num is ignored + * + * Create a device to work with a new style i2c driver, where binding is + * handled through driver model probe()/remove() methods. This call is not + * appropriate for use by mainboad initialization logic, which usually runs + * during an arch_initcall() long before any i2c_adapter could exist. + * + * This returns the new i2c client, which may be saved for later use with + * i2c_unregister_device(); or NULL to indicate an error. + */ +struct i2c_client * +i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info) +{ + struct i2c_client *client; + int status; + + client = kzalloc(sizeof *client, GFP_KERNEL); + if (!client) + return NULL; + + client->adapter = adap; + + client->dev.platform_data = info->platform_data; + client->flags = info->flags; + client->addr = info->addr; + client->irq = info->irq; + + strlcpy(client->driver_name, info->driver_name, + sizeof(client->driver_name)); + strlcpy(client->name, info->type, sizeof(client->name)); + + /* a new style driver may be bound to this device when we + * return from this function, or any later moment (e.g. maybe + * hotplugging will load the driver module). and the device + * refcount model is the standard driver model one. + */ + status = i2c_attach_client(client); + if (status < 0) { + kfree(client); + client = NULL; + } + return client; +} +EXPORT_SYMBOL_GPL(i2c_new_device); + + +/** + * i2c_unregister_device - reverse effect of i2c_new_device() + * @client: value returned from i2c_new_device() + */ +void i2c_unregister_device(struct i2c_client *client) { struct i2c_adapter *adapter = client->adapter; struct i2c_driver *driver = client->driver; @@ -213,6 +273,7 @@ static void i2c_unregister_device(struct i2c_client *client) device_unregister(&client->dev); } +EXPORT_SYMBOL_GPL(i2c_unregister_device); /* ------------------------------------------------------------------------- */ @@ -243,6 +304,22 @@ struct class i2c_adapter_class = { .dev_attrs = i2c_adapter_attrs, }; +static void i2c_scan_static_board_info(struct i2c_adapter *adapter) +{ + struct i2c_devinfo *devinfo; + + mutex_lock(&__i2c_board_lock); + list_for_each_entry(devinfo, &__i2c_board_list, list) { + if (devinfo->busnum == adapter->nr + && !i2c_new_device(adapter, + &devinfo->board_info)) + printk(KERN_ERR "i2c-core: can't create i2c%d-%04x\n", + i2c_adapter_id(adapter), + devinfo->board_info.addr); + } + mutex_unlock(&__i2c_board_lock); +} + /* ----- * i2c_add_adapter is called from within the algorithm layer, @@ -311,7 +388,6 @@ out_list: goto out_unlock; } - int i2c_del_adapter(struct i2c_adapter *adap) { struct list_head *item, *_n; @@ -541,9 +617,15 @@ int i2c_attach_client(struct i2c_client *client) client->usage_count = 0; client->dev.parent = &client->adapter->dev; - client->dev.driver = &client->driver->driver; client->dev.bus = &i2c_bus_type; - client->dev.release = &i2c_client_release; + + if (client->driver) + client->dev.driver = &client->driver->driver; + + if (client->driver && !is_newstyle_driver(client->driver)) + client->dev.release = i2c_client_release; + else + client->dev.release = i2c_client_dev_release; snprintf(&client->dev.bus_id[0], sizeof(client->dev.bus_id), "%d-%04x", i2c_adapter_id(adapter), client->addr); diff --git a/drivers/i2c/i2c-core.h b/drivers/i2c/i2c-core.h new file mode 100644 index 0000000..cd5bff8 --- /dev/null +++ b/drivers/i2c/i2c-core.h @@ -0,0 +1,31 @@ +/* + * i2c-core.h - interfaces internal to the I2C framework + * + * 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. + */ + +struct i2c_devinfo { + struct list_head list; + int busnum; + struct i2c_board_info board_info; +}; + +/* board_lock protects board_list and first_dynamic_bus_num. + * only i2c core components are allowed to use these symbols. + */ +extern struct mutex __i2c_board_lock; +extern struct list_head __i2c_board_list; +extern int __i2c_first_dynamic_bus_num; + diff --git a/include/linux/i2c.h b/include/linux/i2c.h index 6802c3a..382a43b 100644 --- a/include/linux/i2c.h +++ b/include/linux/i2c.h @@ -172,6 +172,7 @@ struct i2c_client { int usage_count; /* How many accesses currently */ /* to the client */ struct device dev; /* the device structure */ + int irq; /* irq issued by device (or -1) */ char driver_name[KOBJ_NAME_LEN]; struct list_head list; struct completion released; @@ -193,6 +194,67 @@ static inline void i2c_set_clientdata (struct i2c_client *dev, void *data) dev_set_drvdata (&dev->dev, data); } +/** + * struct i2c_board_info - template for device creation + * @driver_name: identifies the driver to be bound to the device + * @type: optional chip type information, to initialize i2c_client.name + * @flags: to initialize i2c_client.flags + * @addr: stored in i2c_client.addr + * @platform_data: stored in i2c_client.dev.platform_data + * @irq: stored in i2c_client.irq + + * I2C doesn't actually support hardware probing, although controllers and + * devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's + * a device at a given address. Drivers commonly need more information than + * that, such as chip type, configuration, associated IRQ, and so on. + * + * i2c_board_info is used to build tables of information listing I2C devices + * that are present. This information is used to grow the driver model tree + * for "new style" I2C drivers. For mainboards this is done statically using + * i2c_register_board_info(), where @bus_num represents an adapter that isn't + * yet available. For add-on boards, i2c_new_device() does this dynamically + * with the adapter already known. + */ +struct i2c_board_info { + char driver_name[KOBJ_NAME_LEN]; + char type[I2C_NAME_SIZE]; + unsigned short flags; + unsigned short addr; + void *platform_data; + int irq; +}; + +/** + * I2C_BOARD_INFO - macro used to list an i2c device and its driver + * @driver: identifies the driver to use with the device + * @dev_addr: the device's address on the bus. + * + * This macro initializes essential fields of a struct i2c_board_info, + * declaring what has been provided on a particular board. Optional + * fields (such as the chip type, its associated irq, or device-specific + * platform_data) are provided using conventional syntax. + */ +#define I2C_BOARD_INFO(driver,dev_addr) \ + .driver_name = (driver), .addr = (dev_addr) + + +/* Add-on boards should register/unregister their devices; e.g. a board + * with integrated I2C, a config eeprom, sensors, and a codec that's + * used in conjunction with the primary hardware. + */ +extern struct i2c_client * +i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info); + +extern void i2c_unregister_device(struct i2c_client *); + +/* Mainboard arch_initcall() code should register all its I2C devices. + * This is done at arch_initcall time, before declaring any i2c adapters. + * Modules for add-on boards must use other calls. + */ +extern int +i2c_register_board_info(int busnum, struct i2c_board_info const *info, unsigned n); + + /* * The following structs are for those who like to implement new bus drivers: * i2c_algorithm is the interface to a class of hardware solutions which can |
