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>

1 files changed, 21 insertions, 14 deletions

diff --git a/drivers/i2c/busses/i2c-ocores.c b/drivers/i2c/busses/i2c-ocores.c
index 3fc76b6ffcaa..abf5db7e441e 100644
--- a/drivers/i2c/busses/i2c-ocores.c
+++ b/drivers/i2c/busses/i2c-ocores.c
@@ -354,20 +354,24 @@ 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",
-                                        &val)) {
-                if (!clock_frequency_present) {
-                        dev_err(&pdev->dev,
-                                "Missing required parameter 'opencores,ip-clock-frequency'\n");
-                        return -ENODEV;
+        }
+
+        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,
+                                        "Missing required parameter 'opencores,ip-clock-frequency'\n");
+                                return -ENODEV;
+                        }
+                        i2c->ip_clock_khz = clock_frequency / 1000;
+                        dev_warn(&pdev->dev,
+                                 "Deprecated usage of the 'clock-frequency' property, please update to 'opencores,ip-clock-frequency'\n");
+                } else {
+                        i2c->ip_clock_khz = val / 1000;
+                        if (clock_frequency_present)
+                                i2c->bus_clock_khz = clock_frequency / 1000;
                 }
-                i2c->ip_clock_khz = clock_frequency / 1000;
-                dev_warn(&pdev->dev,
-                         "Deprecated usage of the 'clock-frequency' property, please update to 'opencores,ip-clock-frequency'\n");
-        } else {
-                i2c->ip_clock_khz = val / 1000;
-                if (clock_frequency_present)
-                        i2c->bus_clock_khz = clock_frequency / 1000;
         }
 
         of_property_read_u32(pdev->dev.of_node, "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);
 }