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authorThomas Petazzoni <thomas.petazzoni@free-electrons.com>2016-04-22 15:19:52 +0200
committerWolfram Sang <wsa@the-dreams.de>2016-04-27 19:03:02 +0200
commit9f4d6f164229d4221272186597d9393f654adbb9 (patch)
tree2b3bdaf50f616769684ba2004d27fd78367e0280
parent05872b8039101867e7312c6c3a560b887b2d9079 (diff)
i2c: mv64xxx: handle probe deferral for the clock
If a clock is registered by a platform driver and not by the OF_CLK_DECLARE() mechanism, it might show up after the first attempt to probe i2c-mv64xxx. In order to solve this, we need to handle -EPROBE_PREFER as a special return value of devm_clk_get(), and return the same error code from probe(). This gives us three situations: - There is no reference to a clock in the DT. In this case, devm_clk_get() returns an error that is not -EPROBE_DEFER (something like -ENODEV), and we continue the probing without enabling the clock. - There is a reference to the clock in the DT, and the clock is ready. devm_clk_get() returns a valid reference to the clock, and we prepare/enable it. - There is a reference to the clock in the DT, but the clock is not ready. devm_clk_get() returns -EPROBE_DEFER, and we exit from probe() with the same error code so that probe() is tried again later. This is needed for Marvell Armada 7K/8K, where the clock driver is a platform driver. Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
-rw-r--r--drivers/i2c/busses/i2c-mv64xxx.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-mv64xxx.c b/drivers/i2c/busses/i2c-mv64xxx.c
index 43207f5..4c6282a 100644
--- a/drivers/i2c/busses/i2c-mv64xxx.c
+++ b/drivers/i2c/busses/i2c-mv64xxx.c
@@ -910,6 +910,8 @@ mv64xxx_i2c_probe(struct platform_device *pd)
#if defined(CONFIG_HAVE_CLK)
/* Not all platforms have a clk */
drv_data->clk = devm_clk_get(&pd->dev, NULL);
+ if (IS_ERR(drv_data->clk) && PTR_ERR(drv_data->clk) == -EPROBE_DEFER)
+ return -EPROBE_DEFER;
if (!IS_ERR(drv_data->clk)) {
clk_prepare(drv_data->clk);
clk_enable(drv_data->clk);