i2c: designware_i2c: Add a little more debugging

Add debugging for a few more values and also use log to show return values
when something goes wrong. This makes it easier to see the root cause.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Wolfgang Wallner <wolfgang.wallner@br-automation.com>
Reviewed-by: Heiko Schocher <hs@denx.de>

diff --git a/drivers/i2c/designware_i2c.c b/drivers/i2c/designware_i2c.c
index 3616e2105fab36e2689cefb9ae8871fb44cd9835..44a1f3339834e46514a2e2d1083e66fe9265d50c 100644 (file)
--- a/drivers/i2c/designware_i2c.c
+++ b/drivers/i2c/designware_i2c.c
@@ -160,9 +160,9 @@ static int dw_i2c_calc_timing(struct dw_i2c *priv, enum i2c_speed_mode mode,
        min_tlow_cnt = calc_counts(ic_clk, info->min_scl_lowtime_ns);
        min_thigh_cnt = calc_counts(ic_clk, info->min_scl_hightime_ns);
 
-       debug("dw_i2c: period %d rise %d fall %d tlow %d thigh %d spk %d\n",
-             period_cnt, rise_cnt, fall_cnt, min_tlow_cnt, min_thigh_cnt,
-             spk_cnt);
+       debug("dw_i2c: mode %d, ic_clk %d, speed %d, period %d rise %d fall %d tlow %d thigh %d spk %d\n",
+             mode, ic_clk, info->speed, period_cnt, rise_cnt, fall_cnt,
+             min_tlow_cnt, min_thigh_cnt, spk_cnt);
 
        /*
         * Back-solve for hcnt and lcnt according to the following equations:
@@ -174,7 +174,7 @@ static int dw_i2c_calc_timing(struct dw_i2c *priv, enum i2c_speed_mode mode,
 
        if (hcnt < 0 || lcnt < 0) {
                debug("dw_i2c: bad counts. hcnt = %d lcnt = %d\n", hcnt, lcnt);
-               return -EINVAL;
+               return log_msg_ret("counts", -EINVAL);
        }
 
        /*
@@ -713,7 +713,7 @@ static int designware_i2c_set_bus_speed(struct udevice *bus, unsigned int speed)
 #if CONFIG_IS_ENABLED(CLK)
        rate = clk_get_rate(&i2c->clk);
        if (IS_ERR_VALUE(rate))
-               return -EINVAL;
+               return log_ret(-EINVAL);
 #else
        rate = IC_CLK;
 #endif