diff options
Diffstat (limited to 'linux/drivers/media/video/v4l2-common.c')
| -rw-r--r-- | linux/drivers/media/video/v4l2-common.c | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/linux/drivers/media/video/v4l2-common.c b/linux/drivers/media/video/v4l2-common.c index e87a04a60..6d5e41ecc 100644 --- a/linux/drivers/media/video/v4l2-common.c +++ b/linux/drivers/media/video/v4l2-common.c @@ -58,6 +58,7 @@ #include <asm/div64.h> #define __OLD_VIDIOC_ /* To allow fixing old calls*/ #include <media/v4l2-common.h> +#include <media/v4l2-device.h> #include <media/v4l2-chip-ident.h> #include <linux/videodev2.h> @@ -802,4 +803,173 @@ int v4l2_i2c_attach(struct i2c_adapter *adapter, int address, struct i2c_driver return err != -ENOMEM ? 0 : err; } EXPORT_SYMBOL(v4l2_i2c_attach); + +void v4l2_i2c_subdev_init(struct v4l2_subdev *sd, struct i2c_client *client, + const struct v4l2_subdev_ops *ops) +{ + v4l2_subdev_init(sd, ops); + /* the owner is the same as the i2c_client's driver owner */ + sd->owner = client->driver->driver.owner; + /* i2c_client and v4l2_subdev point to one another */ + v4l2_set_subdevdata(sd, client); + i2c_set_clientdata(client, sd); + /* initialize name */ + snprintf(sd->name, sizeof(sd->name), "%s %d-%04x", + client->driver->driver.name, i2c_adapter_id(client->adapter), + client->addr); +} +EXPORT_SYMBOL_GPL(v4l2_i2c_subdev_init); + +#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 22) +/* Supporting function to find a client on a specific address on the + given adapter. Used for legacy i2c drivers. */ +static struct i2c_client *v4l2_i2c_legacy_find_client(struct i2c_adapter *adap, u8 addr) +{ + struct i2c_client *result = NULL; + struct i2c_client *client; + struct list_head *item; + +#if LINUX_VERSION_CODE <= KERNEL_VERSION(2, 6, 16) + down(&adap->clist_lock); +#else + mutex_lock(&adap->clist_lock); +#endif + list_for_each(item, &adap->clients) { + client = list_entry(item, struct i2c_client, list); + if (client->addr == addr) { + result = client; + break; + } + } +#if LINUX_VERSION_CODE <= KERNEL_VERSION(2, 6, 16) + up(&adap->clist_lock); +#else + mutex_unlock(&adap->clist_lock); +#endif + return result; +} +#endif + + +/* Load an i2c sub-device. It assumes that i2c_get_adapdata(adapter) + returns the v4l2_device and that i2c_get_clientdata(client) + returns the v4l2_subdev. */ +struct v4l2_subdev *v4l2_i2c_new_subdev(struct i2c_adapter *adapter, + const char *module_name, const char *client_type, u8 addr) +{ + struct v4l2_device *dev = i2c_get_adapdata(adapter); + struct v4l2_subdev *sd = NULL; + struct i2c_client *client; +#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 22) + struct i2c_board_info info; +#endif + + BUG_ON(!dev); +#ifdef MODULE + if (module_name) + request_module(module_name); +#endif +#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 22) + /* Setup the i2c board info with the device type and + the device address. */ + memset(&info, 0, sizeof(info)); +#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 26) + strlcpy(info.driver_name, client_type, sizeof(info.driver_name)); +#else + strlcpy(info.type, client_type, sizeof(info.type)); +#endif + info.addr = addr; + + /* Create the i2c client */ + client = i2c_new_device(adapter, &info); +#else + /* Legacy code: loading the module automatically + probes and creates the i2c_client on the adapter. + Try to find the client by walking the adapter's client list. */ + client = v4l2_i2c_legacy_find_client(adapter, addr); +#endif + /* Note: it is possible in the future that + c->driver is NULL if the driver is still being loaded. + We need better support from the kernel so that we + can easily wait for the load to finish. */ + if (client == NULL || client->driver == NULL) + return NULL; + + /* Lock the module so we can safely get the v4l2_subdev pointer */ + if (!try_module_get(client->driver->driver.owner)) + return NULL; + sd = i2c_get_clientdata(client); + + /* Register with the v4l2_device which increases the module's + use count as well. */ + if (v4l2_device_register_subdev(dev, sd)) + sd = NULL; + /* Decrease the module use count to match the first try_module_get. */ + module_put(client->driver->driver.owner); + return sd; + +} +EXPORT_SYMBOL_GPL(v4l2_i2c_new_subdev); + +/* Probe and load an i2c sub-device. It assumes that i2c_get_adapdata(adapter) + returns the v4l2_device and that i2c_get_clientdata(client) + returns the v4l2_subdev. */ +struct v4l2_subdev *v4l2_i2c_new_probed_subdev(struct i2c_adapter *adapter, + const char *module_name, const char *client_type, + const unsigned short *addrs) +{ + struct v4l2_device *dev = i2c_get_adapdata(adapter); + struct v4l2_subdev *sd = NULL; + struct i2c_client *client = NULL; +#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 22) + struct i2c_board_info info; +#endif + + BUG_ON(!dev); +#ifdef MODULE + if (module_name) + request_module(module_name); +#endif +#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 22) + /* Setup the i2c board info with the device type and + the device address. */ + memset(&info, 0, sizeof(info)); +#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 26) + strlcpy(info.driver_name, client_type, sizeof(info.driver_name)); +#else + strlcpy(info.type, client_type, sizeof(info.type)); +#endif + + /* Probe and create the i2c client */ + client = i2c_new_probed_device(adapter, &info, addrs); +#else + /* Legacy code: loading the module should automatically + probe and create the i2c_client on the adapter. + Try to find the client by walking the adapter's client list + for each of the possible addresses. */ + while (!client && *addrs != I2C_CLIENT_END) + client = v4l2_i2c_legacy_find_client(adapter, *addrs++); +#endif + /* Note: it is possible in the future that + c->driver is NULL if the driver is still being loaded. + We need better support from the kernel so that we + can easily wait for the load to finish. */ + if (client == NULL || client->driver == NULL) + return NULL; + + /* Lock the module so we can safely get the v4l2_subdev pointer */ + if (!try_module_get(client->driver->driver.owner)) + return NULL; + sd = i2c_get_clientdata(client); + + /* Register with the v4l2_device which increases the module's + use count as well. */ + if (v4l2_device_register_subdev(dev, sd)) + sd = NULL; + /* Decrease the module use count to match the first try_module_get. */ + module_put(client->driver->driver.owner); + return sd; +} +EXPORT_SYMBOL_GPL(v4l2_i2c_new_probed_subdev); + #endif |