i2c: UniPhier: add driver for UniPhier i2c controller

[u-boot] / drivers / i2c / omap24xx_i2c.c

diff --git a/drivers/i2c/omap24xx_i2c.c b/drivers/i2c/omap24xx_i2c.c
index a39b5917ecd89f0bb11f048e4cde9d721250e574..0f1e35c460ca375aa517dcb4a9d098927ef91d37 100644 (file)
--- a/drivers/i2c/omap24xx_i2c.c
+++ b/drivers/i2c/omap24xx_i2c.c
@@ -153,11 +153,60 @@ static uint omap24_i2c_setspeed(struct i2c_adapter *adap, uint speed)
 
        return 0;
 }
+
+static void omap24_i2c_deblock(struct i2c_adapter *adap)
+{
+       struct i2c *i2c_base = omap24_get_base(adap);
+       int i;
+       u16 systest;
+       u16 orgsystest;
+
+       /* set test mode ST_EN = 1 */
+       orgsystest = readw(&i2c_base->systest);
+       systest = orgsystest;
+       /* enable testmode */
+       systest |= I2C_SYSTEST_ST_EN;
+       writew(systest, &i2c_base->systest);
+       systest &= ~I2C_SYSTEST_TMODE_MASK;
+       systest |= 3 << I2C_SYSTEST_TMODE_SHIFT;
+       writew(systest, &i2c_base->systest);
+
+       /* set SCL, SDA  = 1 */
+       systest |= I2C_SYSTEST_SCL_O | I2C_SYSTEST_SDA_O;
+       writew(systest, &i2c_base->systest);
+       udelay(10);
+
+       /* toggle scl 9 clocks */
+       for (i = 0; i < 9; i++) {
+               /* SCL = 0 */
+               systest &= ~I2C_SYSTEST_SCL_O;
+               writew(systest, &i2c_base->systest);
+               udelay(10);
+               /* SCL = 1 */
+               systest |= I2C_SYSTEST_SCL_O;
+               writew(systest, &i2c_base->systest);
+               udelay(10);
+       }
+
+       /* send stop */
+       systest &= ~I2C_SYSTEST_SDA_O;
+       writew(systest, &i2c_base->systest);
+       udelay(10);
+       systest |= I2C_SYSTEST_SCL_O | I2C_SYSTEST_SDA_O;
+       writew(systest, &i2c_base->systest);
+       udelay(10);
+
+       /* restore original mode */
+       writew(orgsystest, &i2c_base->systest);
+}
+
 static void omap24_i2c_init(struct i2c_adapter *adap, int speed, int slaveadd)
 {
        struct i2c *i2c_base = omap24_get_base(adap);
        int timeout = I2C_TIMEOUT;
+       int deblock = 1;
 
+retry:
        if (readw(&i2c_base->con) & I2C_CON_EN) {
                writew(0, &i2c_base->con);
                udelay(50000);
@@ -194,6 +243,14 @@ static void omap24_i2c_init(struct i2c_adapter *adap, int speed, int slaveadd)
        udelay(1000);
        flush_fifo(adap);
        writew(0xFFFF, &i2c_base->stat);
+
+       /* Handle possible failed I2C state */
+       if (wait_for_bb(adap))
+               if (deblock == 1) {
+                       omap24_i2c_deblock(adap);
+                       deblock = 0;
+                       goto retry;
+               }
 }
 
 static void flush_fifo(struct i2c_adapter *adap)