[COMMON] i2c: exynos5: Add MASTER INIT STATUS check

Master will know a transaction done by watching trans status SFR.
From USIv2 this status SFR has been changed, INIT status(0x1) represents
previous IDLE status(0x0)

Change-Id: I54e815a6833962e359c9adcb2865e82e3ad4338e
Signed-off-by: Kyungwoo Kang <kwoo.kang@samsung.com>

diff --git a/drivers/i2c/busses/i2c-exynos5.c b/drivers/i2c/busses/i2c-exynos5.c
index 2657edaeb76a72e5589b02e0fe3ba4a02436b506..6c4d0ac05849d5af3372d447e6928487349db229 100644 (file)
--- a/drivers/i2c/busses/i2c-exynos5.c
+++ b/drivers/i2c/busses/i2c-exynos5.c
@@ -157,6 +157,7 @@ static LIST_HEAD(drvdata_list);
 #define HSI2C_TRANS_ABORT                      (1u << 1)
 #define HSI2C_TRANS_DONE                       (1u << 0)
 #define HSI2C_MAST_ST_MASK                     (0xf << 0)
+#define HSI2C_MASTER_ST_INIT                   (0x1)
 
 /* I2C_TRANS_STATUS register bits for Exynos7 variant */
 #define HSI2C_MASTER_ST_MASK                   0xf
@@ -568,6 +569,7 @@ static int exynos5_i2c_xfer_msg(struct exynos5_i2c *i2c,
                              struct i2c_msg *msgs, int stop)
 {
        unsigned long timeout;
+       unsigned long trans_status;
        unsigned long i2c_ctl;
        unsigned long i2c_auto_conf;
        unsigned long i2c_timeout;
@@ -676,6 +678,22 @@ static int exynos5_i2c_xfer_msg(struct exynos5_i2c *i2c,
                                (&i2c->msg_complete, EXYNOS5_I2C_TIMEOUT);
 
                        ret = 0;
+
+                       if (i2c->scl_clk_stretch) {
+                               unsigned long timeout = jiffies + msecs_to_jiffies(100);
+
+                               do {
+                                       trans_status = readl(i2c->regs + HSI2C_TRANS_STATUS);
+                                       if ((trans_status & HSI2C_MAST_ST_MASK) == HSI2C_MASTER_ST_INIT){
+                                               timeout = 0;
+                                               break;
+                                       }
+                               } while(time_before(jiffies, timeout));
+
+                               if (timeout)
+                                       dev_err(i2c->dev, "SDA check timeout AT READ!!! = 0x%8lx\n",trans_status);
+                       }
+
                        disable_irq(i2c->irq);
 
                        if (i2c->trans_done < 0) {
@@ -743,8 +761,24 @@ static int exynos5_i2c_xfer_msg(struct exynos5_i2c *i2c,
                                dev_err(i2c->dev, "ack was not received at write\n");
                                ret = i2c->trans_done;
                                exynos5_i2c_reset(i2c);
-                       } else
+                       } else {
+                               if (i2c->scl_clk_stretch) {
+                                       unsigned long timeout = jiffies + msecs_to_jiffies(100);
+
+                                       do {
+                                               trans_status = readl(i2c->regs + HSI2C_TRANS_STATUS);
+                                               if ((trans_status & HSI2C_MAST_ST_MASK) == HSI2C_MASTER_ST_INIT){
+                                                       timeout = 0;
+                                                       break;
+                                               }
+                                       } while(time_before(jiffies, timeout));
+
+                                       if (timeout)
+                                               dev_err(i2c->dev, "SDA check timeout AT WRITE!!! = 0x%8lx\n",trans_status);
+                               }
+
                                ret = 0;
+                       }
                }
        }