3 files changed, 25 insertions, 11 deletions

diff --git a/drivers/i2c/busses/i2c-designware-core.c b/drivers/i2c/busses/i2c-designware-core.c
index 14c4b30d4ccc..22e92c3d3d07 100644
--- a/drivers/i2c/busses/i2c-designware-core.c
+++ b/drivers/i2c/busses/i2c-designware-core.c
@@ -218,7 +218,7 @@ i2c_dw_scl_hcnt(u32 ic_clk, u32 tSYMBOL, u32 tf, int cond, int offset)
                  *
                  * If your hardware is free from tHD;STA issue, try this one.
                  */
-                return (ic_clk * tSYMBOL + 5000) / 10000 - 8 + offset;
+                return (ic_clk * tSYMBOL + 500000) / 1000000 - 8 + offset;
         else
                 /*
                  * Conditional expression:
@@ -234,7 +234,8 @@ i2c_dw_scl_hcnt(u32 ic_clk, u32 tSYMBOL, u32 tf, int cond, int offset)
                  * The reason why we need to take into account "tf" here,
                  * is the same as described in i2c_dw_scl_lcnt().
                  */
-                return (ic_clk * (tSYMBOL + tf) + 5000) / 10000 - 3 + offset;
+                return (ic_clk * (tSYMBOL + tf) + 500000) / 1000000
+                        - 3 + offset;
 }
 
 static u32 i2c_dw_scl_lcnt(u32 ic_clk, u32 tLOW, u32 tf, int offset)
@@ -250,7 +251,7 @@ static u32 i2c_dw_scl_lcnt(u32 ic_clk, u32 tLOW, u32 tf, int offset)
          * account the fall time of SCL signal (tf).  Default tf value
          * should be 0.3 us, for safety.
          */
-        return ((ic_clk * (tLOW + tf) + 5000) / 10000) - 1 + offset;
+        return ((ic_clk * (tLOW + tf) + 500000) / 1000000) - 1 + offset;
 }
 
 static void __i2c_dw_enable(struct dw_i2c_dev *dev, bool enable)
@@ -287,6 +288,7 @@ int i2c_dw_init(struct dw_i2c_dev *dev)
         u32 input_clock_khz;
         u32 hcnt, lcnt;
         u32 reg;
+        u32 sda_falling_time, scl_falling_time;
 
         input_clock_khz = dev->get_clk_rate_khz(dev);
 
@@ -308,15 +310,18 @@ int i2c_dw_init(struct dw_i2c_dev *dev)
 
         /* set standard and fast speed deviders for high/low periods */
 
+        sda_falling_time = dev->sda_falling_time ?: 300; /* ns */
+        scl_falling_time = dev->scl_falling_time ?: 300; /* ns */
+
         /* Standard-mode */
         hcnt = i2c_dw_scl_hcnt(input_clock_khz,
-                                40,     /* tHD;STA = tHIGH = 4.0 us */
-                                3,      /* tf = 0.3 us */
+                                4000,   /* tHD;STA = tHIGH = 4.0 us */
+                                sda_falling_time,
                                 0,      /* 0: DW default, 1: Ideal */
                                 0);     /* No offset */
         lcnt = i2c_dw_scl_lcnt(input_clock_khz,
-                                47,     /* tLOW = 4.7 us */
-                                3,      /* tf = 0.3 us */
+                                4700,   /* tLOW = 4.7 us */
+                                scl_falling_time,
                                 0);     /* No offset */
 
         /* Allow platforms to specify the ideal HCNT and LCNT values */
@@ -330,13 +335,13 @@ int i2c_dw_init(struct dw_i2c_dev *dev)
 
         /* Fast-mode */
         hcnt = i2c_dw_scl_hcnt(input_clock_khz,
-                                6,      /* tHD;STA = tHIGH = 0.6 us */
-                                3,      /* tf = 0.3 us */
+                                600,    /* tHD;STA = tHIGH = 0.6 us */
+                                sda_falling_time,
                                 0,      /* 0: DW default, 1: Ideal */
                                 0);     /* No offset */
         lcnt = i2c_dw_scl_lcnt(input_clock_khz,
-                                13,     /* tLOW = 1.3 us */
-                                3,      /* tf = 0.3 us */
+                                1300,   /* tLOW = 1.3 us */
+                                scl_falling_time,
                                 0);     /* No offset */
 
         if (dev->fs_hcnt && dev->fs_lcnt) {
diff --git a/drivers/i2c/busses/i2c-designware-core.h b/drivers/i2c/busses/i2c-designware-core.h
index e8a756537ed0..d66b6cbc9edc 100644
--- a/drivers/i2c/busses/i2c-designware-core.h
+++ b/drivers/i2c/busses/i2c-designware-core.h
@@ -99,6 +99,8 @@ struct dw_i2c_dev {
         unsigned int            rx_fifo_depth;
         int                     rx_outstanding;
         u32                     sda_hold_time;
+        u32                     sda_falling_time;
+        u32                     scl_falling_time;
         u16                     ss_hcnt;
         u16                     ss_lcnt;
         u16                     fs_hcnt;
diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c
index d0bdac0498ce..fc243992b4b4 100644
--- a/drivers/i2c/busses/i2c-designware-platdrv.c
+++ b/drivers/i2c/busses/i2c-designware-platdrv.c
@@ -159,6 +159,13 @@ static int dw_i2c_probe(struct platform_device *pdev)
                                         "i2c-sda-hold-time-ns", &ht);
                 dev->sda_hold_time = div_u64((u64)ic_clk * ht + 500000,
                                              1000000);
+
+                of_property_read_u32(pdev->dev.of_node,
+                                     "i2c-sda-falling-time-ns",
+                                     &dev->sda_falling_time);
+                of_property_read_u32(pdev->dev.of_node,
+                                     "i2c-scl-falling-time-ns",
+                                     &dev->scl_falling_time);
         }
 
         dev->functionality =