From: Jean Delvare Date: Sat, 7 Nov 2009 12:10:46 +0000 (+0100) Subject: i2c: Add an interface to lock/unlock an I2C bus segment X-Git-Tag: v3.0~7002^2 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=afa08974fe80c198b8650f73ed8ab59135ca10d0;p=platform%2Fkernel%2Flinux-amlogic.git i2c: Add an interface to lock/unlock an I2C bus segment Some drivers need to be able to prevent access to an I2C bus segment for a specific period of time. Add an interface for them to do so without twiddling with i2c-core internals. Signed-off-by: Jean Delvare Acked-by: Ben Hutchings --- diff --git a/drivers/net/sfc/sfe4001.c b/drivers/net/sfc/sfe4001.c index cee00ad..49eb91b 100644 --- a/drivers/net/sfc/sfe4001.c +++ b/drivers/net/sfc/sfe4001.c @@ -188,7 +188,7 @@ static int sfn4111t_reset(struct efx_nic *efx) efx_oword_t reg; /* GPIO 3 and the GPIO register are shared with I2C, so block that */ - mutex_lock(&efx->i2c_adap.bus_lock); + i2c_lock_adapter(&efx->i2c_adap); /* Pull RST_N (GPIO 2) low then let it up again, setting the * FLASH_CFG_1 strap (GPIO 3) appropriately. Only change the @@ -204,7 +204,7 @@ static int sfn4111t_reset(struct efx_nic *efx) falcon_write(efx, ®, GPIO_CTL_REG_KER); msleep(1); - mutex_unlock(&efx->i2c_adap.bus_lock); + i2c_unlock_adapter(&efx->i2c_adap); ssleep(1); return 0; diff --git a/include/linux/i2c.h b/include/linux/i2c.h index 57d41b0..7b40cda 100644 --- a/include/linux/i2c.h +++ b/include/linux/i2c.h @@ -361,6 +361,24 @@ static inline void i2c_set_adapdata(struct i2c_adapter *dev, void *data) dev_set_drvdata(&dev->dev, data); } +/** + * i2c_lock_adapter - Prevent access to an I2C bus segment + * @adapter: Target I2C bus segment + */ +static inline void i2c_lock_adapter(struct i2c_adapter *adapter) +{ + mutex_lock(&adapter->bus_lock); +} + +/** + * i2c_unlock_adapter - Reauthorize access to an I2C bus segment + * @adapter: Target I2C bus segment + */ +static inline void i2c_unlock_adapter(struct i2c_adapter *adapter) +{ + mutex_unlock(&adapter->bus_lock); +} + /*flags for the client struct: */ #define I2C_CLIENT_PEC 0x04 /* Use Packet Error Checking */ #define I2C_CLIENT_TEN 0x10 /* we have a ten bit chip address */