diff options
| author | Chew, Chiau Ee <chiau.ee.chew@intel.com> | 2013-09-27 02:57:35 +0800 |
|---|---|---|
| committer | Wolfram Sang <wsa@the-dreams.de> | 2013-09-27 18:12:31 +0200 |
| commit | bd63ace4dc4290165bbf3bf546eba50453d0aa9d (patch) | |
| tree | 943d8582cc7cd5fb470b816d4ac6df7c600084ea | |
| parent | 85b3a9356e84f683dd27fe8b73ad15608b4fc2c5 (diff) | |
| download | linux-bd63ace4dc4290165bbf3bf546eba50453d0aa9d.tar.bz2 | |
i2c: designware: 10-bit addressing mode enabling if I2C_DYNAMIC_TAR_UPDATE is set
According to Designware I2C spec, if I2C_DYNAMIC_TAR_UPDATE is set to 1,
the 10-bit addressing mode is controlled by IC_10BITADDR_MASTER bit of
IC_TAR register instead of IC_CON register. The IC_10BITADDR_MASTER
in IC_CON register becomes read-only copy. Since I2C_DYNAMIC_TAR_UPDATE
value can't be detected from hardware register, so we will always set the
IC_10BITADDR_MASTER bit in both IC_CON and IC_TAR register whenever 10-bit
addresing mode is requested by user application.
Signed-off-by: Chew, Chiau Ee <chiau.ee.chew@intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| -rw-r--r-- | drivers/i2c/busses/i2c-designware-core.c | 26 |
1 files changed, 20 insertions, 6 deletions
diff --git a/drivers/i2c/busses/i2c-designware-core.c b/drivers/i2c/busses/i2c-designware-core.c index dbecf08399f8..5888feef1ac5 100644 --- a/drivers/i2c/busses/i2c-designware-core.c +++ b/drivers/i2c/busses/i2c-designware-core.c @@ -98,6 +98,8 @@ #define DW_IC_ERR_TX_ABRT 0x1 +#define DW_IC_TAR_10BITADDR_MASTER BIT(12) + /* * status codes */ @@ -388,22 +390,34 @@ static int i2c_dw_wait_bus_not_busy(struct dw_i2c_dev *dev) static void i2c_dw_xfer_init(struct dw_i2c_dev *dev) { struct i2c_msg *msgs = dev->msgs; - u32 ic_con; + u32 ic_con, ic_tar = 0; /* Disable the adapter */ __i2c_dw_enable(dev, false); - /* set the slave (target) address */ - dw_writel(dev, msgs[dev->msg_write_idx].addr, DW_IC_TAR); - /* if the slave address is ten bit address, enable 10BITADDR */ ic_con = dw_readl(dev, DW_IC_CON); - if (msgs[dev->msg_write_idx].flags & I2C_M_TEN) + if (msgs[dev->msg_write_idx].flags & I2C_M_TEN) { ic_con |= DW_IC_CON_10BITADDR_MASTER; - else + /* + * If I2C_DYNAMIC_TAR_UPDATE is set, the 10-bit addressing + * mode has to be enabled via bit 12 of IC_TAR register. + * We set it always as I2C_DYNAMIC_TAR_UPDATE can't be + * detected from registers. + */ + ic_tar = DW_IC_TAR_10BITADDR_MASTER; + } else { ic_con &= ~DW_IC_CON_10BITADDR_MASTER; + } + dw_writel(dev, ic_con, DW_IC_CON); + /* + * Set the slave (target) address and enable 10-bit addressing mode + * if applicable. + */ + dw_writel(dev, msgs[dev->msg_write_idx].addr | ic_tar, DW_IC_TAR); + /* Enable the adapter */ __i2c_dw_enable(dev, true); |