i2c: ocores: rework clk code to handle NULL cookie

For, !HAVE_CLK the clk API returns a NULL cookie. Rework the
initialization code to handle that. If clk_get_rate() delivers 0, we use
the fallback mechanisms. The patch is pretty easy when ignoring white
space issues (git diff -b).
Suggested-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Tested-by: Max Filippov <jcmvbkbc@gmail.com>

drivers/i2c/busses/i2c-ocores.c

@@ -354,7 +354,10 @@ static int ocores_i2c_of_probe(struct platform_device *pdev,
 		i2c->ip_clock_khz = clk_get_rate(i2c->clk) / 1000;
 		if (clock_frequency_present)
 			i2c->bus_clock_khz = clock_frequency / 1000;
-	} else if (of_property_read_u32(np, "opencores,ip-clock-frequency",
+	}
+
+	if (i2c->ip_clock_khz == 0) {
+		if (of_property_read_u32(np, "opencores,ip-clock-frequency",
 						&val)) {
 			if (!clock_frequency_present) {
 				dev_err(&pdev->dev,
@@ -369,6 +372,7 @@ static int ocores_i2c_of_probe(struct platform_device *pdev,
 			if (clock_frequency_present)
 				i2c->bus_clock_khz = clock_frequency / 1000;
 		}
+	}
 
 	of_property_read_u32(pdev->dev.of_node, "reg-io-width",
 				&i2c->reg_io_width);
@@ -518,6 +522,7 @@ static int ocores_i2c_resume(struct device *dev)
 	struct ocores_i2c *i2c = dev_get_drvdata(dev);
 
 	if (!IS_ERR(i2c->clk)) {
+		unsigned long rate;
 		int ret = clk_prepare_enable(i2c->clk);
 
 		if (ret) {
@@ -525,7 +530,9 @@ static int ocores_i2c_resume(struct device *dev)
 				"clk_prepare_enable failed: %d\n", ret);
 			return ret;
 		}
-		i2c->ip_clock_khz = clk_get_rate(i2c->clk) / 1000;
+		rate = clk_get_rate(i2c->clk) / 1000;
+		if (rate)
+			i2c->ip_clock_khz = rate;
 	}
 	return ocores_init(dev, i2c);
 }