From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail.amk-drives.bg ([213.91.234.2]) by canuck.infradead.org with smtp (Exim 4.76 #1 (Red Hat Linux)) id 1R9BUR-0005iD-3c for barebox@lists.infradead.org; Thu, 29 Sep 2011 07:57:08 +0000 From: Rosen Kolev Date: Thu, 29 Sep 2011 11:57:02 +0300 Message-Id: <1317286622-7477-1-git-send-email-rosen.kolev@amk-drives.bg> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: barebox-bounces@lists.infradead.org Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: [PATCH] Allow data-only i2c transfers To: barebox@lists.infradead.org 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 --- drivers/i2c/busses/i2c-imx.c | 52 ++++++++++++++++++++++------------------- 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 2d075f7..d928839 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 2507d68..ccbf518 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 */ -- 1.7.2.3 _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox