i2c: pasemi: Enable the unjam machine

The I2C bus can get stuck under some conditions (desync between
controller and device). The pasemi controllers include an unjam feature
that is enabled on reset, but was being disabled by the driver. Keep it
enabled by explicitly setting the UJM bit in the CTL register. This
should help recover the bus from certain conditions, which would
otherwise remain stuck forever.

Signed-off-by: Hector Martin <marcan@marcan.st>

Author: marcan

drivers/i2c/busses/i2c-pasemi-core.c

@@ -49,6 +49,7 @@
 #define CTL_EN		BIT(11)
 #define CTL_MRR		BIT(10)
 #define CTL_MTR		BIT(9)
+#define CTL_UJM		BIT(8)
 #define CTL_CLK_M	GENMASK(7, 0)
 
 #define TRANSFER_TIMEOUT_MS	100
@@ -72,7 +73,7 @@ static inline int reg_read(struct pasemi_smbus *smbus, int reg)
 
 static void pasemi_reset(struct pasemi_smbus *smbus)
 {
-	u32 val = (CTL_MTR | CTL_MRR | (smbus->clk_div & CTL_CLK_M));
+	u32 val = (CTL_MTR | CTL_MRR | CTL_UJM | (smbus->clk_div & CTL_CLK_M));
 
 	if (smbus->hw_rev >= 6)
 		val |= CTL_EN;