i2c: designware: Do not calculate SCL timing parameters needlessly

Do SCL timing parameter calculation conditionally depending are custom
parameters provided since calculated values will get instantly overwritten
by provided parameters.

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

diff --git a/drivers/i2c/busses/i2c-designware-core.c b/drivers/i2c/busses/i2c-designware-core.c
index fbb48fb138e752ecd5415d4716857d208d1f748e..6e25c010e69037a544ad04f82df46e27e80ca9af 100644 (file)
--- a/drivers/i2c/busses/i2c-designware-core.c
+++ b/drivers/i2c/busses/i2c-designware-core.c
@@ -320,40 +320,39 @@ int i2c_dw_init(struct dw_i2c_dev *dev)
        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,
-                               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,
-                               4700,   /* tLOW = 4.7 us */
-                               scl_falling_time,
-                               0);     /* No offset */
-
-       /* Allow platforms to specify the ideal HCNT and LCNT values */
+       /* Set SCL timing parameters for standard-mode */
        if (dev->ss_hcnt && dev->ss_lcnt) {
                hcnt = dev->ss_hcnt;
                lcnt = dev->ss_lcnt;
+       } else {
+               hcnt = i2c_dw_scl_hcnt(input_clock_khz,
+                                       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,
+                                       4700,   /* tLOW = 4.7 us */
+                                       scl_falling_time,
+                                       0);     /* No offset */
        }
        dw_writel(dev, hcnt, DW_IC_SS_SCL_HCNT);
        dw_writel(dev, lcnt, DW_IC_SS_SCL_LCNT);
        dev_dbg(dev->dev, "Standard-mode HCNT:LCNT = %d:%d\n", hcnt, lcnt);
 
-       /* Fast-mode */
-       hcnt = i2c_dw_scl_hcnt(input_clock_khz,
-                               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,
-                               1300,   /* tLOW = 1.3 us */
-                               scl_falling_time,
-                               0);     /* No offset */
-
+       /* Set SCL timing parameters for fast-mode */
        if (dev->fs_hcnt && dev->fs_lcnt) {
                hcnt = dev->fs_hcnt;
                lcnt = dev->fs_lcnt;
+       } else {
+               hcnt = i2c_dw_scl_hcnt(input_clock_khz,
+                                       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,
+                                       1300,   /* tLOW = 1.3 us */
+                                       scl_falling_time,
+                                       0);     /* No offset */
        }
        dw_writel(dev, hcnt, DW_IC_FS_SCL_HCNT);
        dw_writel(dev, lcnt, DW_IC_FS_SCL_LCNT);