diff options
| author | Rosen Kolev <rosen.kolev@amk-drives.bg> | 2011-09-29 11:57:02 +0300 |
|---|---|---|
| committer | Sascha Hauer <s.hauer@pengutronix.de> | 2011-10-07 15:42:48 +0200 |
| commit | 502ecda2d17ed4b50b6c4d5afb04832013996173 (patch) | |
| tree | 787e1797aac61a2d223bd9fbf6c259c20a365e78 | |
| parent | c7efd11b38fa5c0ec264a2724735df07ec5f08d8 (diff) | |
| download | barebox-502ecda2d17ed4b50b6c4d5afb04832013996173.tar.gz barebox-502ecda2d17ed4b50b6c4d5afb04832013996173.tar.xz | |
Allow data-only i2c transfers
Modified the i2c_imx driver to support data-only transfers, without
command byte. This allows to construct more complex i2c transfers
and support non genuine devices like Atmel ATxx secure memory, where the
master reads data after a write command.
Signed-off-by: Rosen Kolev <rosen.kolev@amk-drives.bg>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
| -rw-r--r-- | drivers/i2c/busses/i2c-imx.c | 52 | ||||
| -rw-r--r-- | include/i2c/i2c.h | 1 |
2 files changed, 29 insertions, 24 deletions
diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c index c1e9cafa80..da6218f43c 100644 --- a/drivers/i2c/busses/i2c-imx.c +++ b/drivers/i2c/busses/i2c-imx.c @@ -314,19 +314,21 @@ static int i2c_imx_write(struct i2c_adapter *adapter, struct i2c_msg *msgs) void __iomem *base = i2c_imx->base; int i, result; - dev_dbg(adapter->dev, - "<%s> write slave address: addr=0x%02x\n", - __func__, msgs->addr << 1); + if ( !(msgs->flags & I2C_M_DATA_ONLY) ) { + dev_dbg(adapter->dev, + "<%s> write slave address: addr=0x%02x\n", + __func__, msgs->addr << 1); - /* write slave address */ - writeb(msgs->addr << 1, base + IMX_I2C_I2DR); + /* write slave address */ + writeb(msgs->addr << 1, base + IMX_I2C_I2DR); - result = i2c_imx_trx_complete(adapter); - if (result) - return result; - result = i2c_imx_acked(adapter); - if (result) - return result; + result = i2c_imx_trx_complete(adapter); + if (result) + return result; + result = i2c_imx_acked(adapter); + if (result) + return result; + } /* write data */ for (i = 0; i < msgs->len; i++) { @@ -352,22 +354,24 @@ static int i2c_imx_read(struct i2c_adapter *adapter, struct i2c_msg *msgs) int i, result; unsigned int temp; - dev_dbg(adapter->dev, - "<%s> write slave address: addr=0x%02x\n", - __func__, (msgs->addr << 1) | 0x01); - /* clear IIF */ writeb(0x0, base + IMX_I2C_I2SR); - /* write slave address */ - writeb((msgs->addr << 1) | 0x01, base + IMX_I2C_I2DR); + if ( !(msgs->flags & I2C_M_DATA_ONLY) ) { + dev_dbg(adapter->dev, + "<%s> write slave address: addr=0x%02x\n", + __func__, (msgs->addr << 1) | 0x01); - result = i2c_imx_trx_complete(adapter); - if (result) - return result; - result = i2c_imx_acked(adapter); - if (result) - return result; + /* write slave address */ + writeb((msgs->addr << 1) | 0x01, base + IMX_I2C_I2DR); + + result = i2c_imx_trx_complete(adapter); + if (result) + return result; + result = i2c_imx_acked(adapter); + if (result) + return result; + } /* setup bus to read data */ temp = readb(base + IMX_I2C_I2CR); @@ -428,7 +432,7 @@ static int i2c_imx_xfer(struct i2c_adapter *adapter, /* read/write data */ for (i = 0; i < num; i++) { - if (i) { + if (i && !(msgs[i].flags & I2C_M_DATA_ONLY)) { temp = readb(base + IMX_I2C_I2CR); temp |= I2CR_RSTA; writeb(temp, base + IMX_I2C_I2CR); diff --git a/include/i2c/i2c.h b/include/i2c/i2c.h index 2507d68a34..ccbf518c97 100644 --- a/include/i2c/i2c.h +++ b/include/i2c/i2c.h @@ -30,6 +30,7 @@ struct i2c_platform_data { #define I2C_NAME_SIZE 20 #define I2C_M_RD 0x0001 /* read data, from slave to master */ +#define I2C_M_DATA_ONLY 0x0002 /* transfer data bytes only */ #define I2C_M_TEN 0x0010 /* this is a ten bit chip address */ #define I2C_M_IGNORE_NAK 0x1000 /* if I2C_FUNC_PROTOCOL_MANGLING */ |