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authorChew, Chiau Ee <chiau.ee.chew@intel.com>2013-09-26 22:57:35 +0400
committerWolfram Sang <wsa@the-dreams.de>2013-09-27 20:12:31 +0400
commitbd63ace4dc4290165bbf3bf546eba50453d0aa9d (patch)
tree943d8582cc7cd5fb470b816d4ac6df7c600084ea /drivers
parent85b3a9356e84f683dd27fe8b73ad15608b4fc2c5 (diff)
downloadlinux-bd63ace4dc4290165bbf3bf546eba50453d0aa9d.tar.xz
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>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/i2c/busses/i2c-designware-core.c26
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);