[PATCH v1 1/3] can: mcp251x: Use devm_clk_get_optional() to get the input clock

[Andy Shevchenko]

Simplify the code which fetches the input clock by using
devm_clk_get_optional(). This comes with a small functional change: previously
all errors were ignored when platform data is present. Now all errors are
treated as errors. If no input clock is present devm_clk_get_optional() will
return NULL instead of an error which matches the behavior of the old code.

Signed-off-by: Andy Shevchenko <andriy.shevche...@linux.intel.com>
---
 drivers/net/can/spi/mcp251x.c | 30 ++++++++++++------------------
 1 file changed, 12 insertions(+), 18 deletions(-)

diff --git a/drivers/net/can/spi/mcp251x.c b/drivers/net/can/spi/mcp251x.c
index 58992fd61cb9..e04b578f2b1f 100644
--- a/drivers/net/can/spi/mcp251x.c
+++ b/drivers/net/can/spi/mcp251x.c
@@ -1014,15 +1014,13 @@ static int mcp251x_can_probe(struct spi_device *spi)
        struct clk *clk;
        int freq, ret;
 
-       clk = devm_clk_get(&spi->dev, NULL);
-       if (IS_ERR(clk)) {
-               if (pdata)
-                       freq = pdata->oscillator_frequency;
-               else
-                       return PTR_ERR(clk);
-       } else {
-               freq = clk_get_rate(clk);
-       }
+       clk = devm_clk_get_optional(&spi->dev, NULL);
+       if (IS_ERR(clk))
+               return PTR_ERR(clk);
+
+       freq = clk_get_rate(clk);
+       if (freq == 0 && pdata)
+               freq = pdata->oscillator_frequency;
 
        /* Sanity check */
        if (freq < 1000000 || freq > 25000000)
@@ -1033,11 +1031,9 @@ static int mcp251x_can_probe(struct spi_device *spi)
        if (!net)
                return -ENOMEM;
 
-       if (!IS_ERR(clk)) {
-               ret = clk_prepare_enable(clk);
-               if (ret)
-                       goto out_free;
-       }
+       ret = clk_prepare_enable(clk);
+       if (ret)
+               goto out_free;
 
        net->netdev_ops = &mcp251x_netdev_ops;
        net->flags |= IFF_ECHO;
@@ -1122,8 +1118,7 @@ static int mcp251x_can_probe(struct spi_device *spi)
        mcp251x_power_enable(priv->power, 0);
 
 out_clk:
-       if (!IS_ERR(clk))
-               clk_disable_unprepare(clk);
+       clk_disable_unprepare(clk);
 
 out_free:
        free_candev(net);
@@ -1141,8 +1136,7 @@ static int mcp251x_can_remove(struct spi_device *spi)
 
        mcp251x_power_enable(priv->power, 0);
 
-       if (!IS_ERR(priv->clk))
-               clk_disable_unprepare(priv->clk);
+       clk_disable_unprepare(priv->clk);
 
        free_candev(net);
 
-- 
2.23.0.rc1