| Message ID | 1335347102-14905-4-git-send-email-thierry.reding@avionic-design.de |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
On 04/25/2012 03:45 AM, Thierry Reding wrote: > This function resolves an OF device node to an I2C adapter registered > with the I2C core. I think this is doing the same thing as a patch I posted recently: http://www.spinics.net/lists/linux-i2c/msg07808.html What's the advantage of one way over the other? -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
* Stephen Warren wrote: > On 04/25/2012 03:45 AM, Thierry Reding wrote: > > This function resolves an OF device node to an I2C adapter registered > > with the I2C core. > > I think this is doing the same thing as a patch I posted recently: > http://www.spinics.net/lists/linux-i2c/msg07808.html I wasn't aware of that patch. > What's the advantage of one way over the other? Both are fine I think. Your version is shorter but mine may be a little faster since it doesn't iterate over all devices on the bus. Since the lookup doesn't happen very frequently this isn't much of an issue. Thierry
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index feb7dc3..e73b044 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -1627,6 +1627,40 @@ void i2c_put_adapter(struct i2c_adapter *adap) } EXPORT_SYMBOL(i2c_put_adapter); +#ifdef CONFIG_OF +static int of_i2c_match_node(int id, void *p, void *data) +{ + struct device_node *node = data; + struct i2c_adapter *adapter = p; + + if (adapter->dev.of_node == node) + return id; + + return 0; +} + +struct i2c_adapter *of_i2c_get_adapter(struct device_node *node) +{ + struct i2c_adapter *adapter = NULL; + int err; + + mutex_lock(&core_lock); + + err = idr_for_each(&i2c_adapter_idr, of_i2c_match_node, node); + if (err < 0) + goto out; + + adapter = idr_find(&i2c_adapter_idr, err); + if (adapter && !try_module_get(adapter->owner)) + adapter = NULL; + +out: + mutex_unlock(&core_lock); + return adapter; +} +EXPORT_SYMBOL(of_i2c_get_adapter); +#endif + /* The SMBus parts */ #define POLY (0x1070U << 3) diff --git a/include/linux/of_i2c.h b/include/linux/of_i2c.h index 0efe8d4..a35c497 100644 --- a/include/linux/of_i2c.h +++ b/include/linux/of_i2c.h @@ -20,11 +20,18 @@ extern void of_i2c_register_devices(struct i2c_adapter *adap); /* must call put_device() when done with returned i2c_client device */ extern struct i2c_client *of_find_i2c_device_by_node(struct device_node *node); +extern struct i2c_adapter *of_i2c_get_adapter(struct device_node *node); + #else static inline void of_i2c_register_devices(struct i2c_adapter *adap) { return; } + +static inline struct i2c_adapter *of_i2c_get_adapter(struct device_node *node) +{ + return NULL; +} #endif /* CONFIG_OF_I2C */ #endif /* __LINUX_OF_I2C_H */
This function resolves an OF device node to an I2C adapter registered with the I2C core. Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de> --- drivers/i2c/i2c-core.c | 34 ++++++++++++++++++++++++++++++++++ include/linux/of_i2c.h | 7 +++++++ 2 files changed, 41 insertions(+)