i2c: designware: Move register access detection to common code

Move register access detection out from master and slave HW
initialization code to common code. Motivation for this is to have
register access configured before HW initialization and remove
duplicated code.

This allows to do further separation between probe time initialization
and runtime reinitialization code.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

1 files changed, 34 insertions, 0 deletions

diff --git a/drivers/i2c/busses/i2c-designware-common.c b/drivers/i2c/busses/i2c-designware-common.c
index 48914dfc8ce8..d1c93acabfcf 100644
--- a/drivers/i2c/busses/i2c-designware-common.c
+++ b/drivers/i2c/busses/i2c-designware-common.c
@@ -94,6 +94,40 @@ void dw_writel(struct dw_i2c_dev *dev, u32 b, int offset)
 	}
 }
 
+/**
+ * i2c_dw_set_reg_access() - Set register access flags
+ * @dev: device private data
+ *
+ * Autodetects needed register access mode and sets access flags accordingly.
+ * This must be called before doing any other register access.
+ */
+int i2c_dw_set_reg_access(struct dw_i2c_dev *dev)
+{
+	u32 reg;
+	int ret;
+
+	ret = i2c_dw_acquire_lock(dev);
+	if (ret)
+		return ret;
+
+	reg = dw_readl(dev, DW_IC_COMP_TYPE);
+	i2c_dw_release_lock(dev);
+
+	if (reg == ___constant_swab32(DW_IC_COMP_TYPE_VALUE)) {
+		/* Configure register endianess access */
+		dev->flags |= ACCESS_SWAP;
+	} else if (reg == (DW_IC_COMP_TYPE_VALUE & 0x0000ffff)) {
+		/* Configure register access mode 16bit */
+		dev->flags |= ACCESS_16BIT;
+	} else if (reg != DW_IC_COMP_TYPE_VALUE) {
+		dev_err(dev->dev,
+			"Unknown Synopsys component type: 0x%08x\n", reg);
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
 u32 i2c_dw_scl_hcnt(u32 ic_clk, u32 tSYMBOL, u32 tf, int cond, int offset)
 {
 	/*