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author | Thomas Petazzoni <thomas.petazzoni@free-electrons.com> | 2016-04-22 15:19:52 +0200 |
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committer | Wolfram Sang <wsa@the-dreams.de> | 2016-04-27 19:03:02 +0200 |
commit | 9f4d6f164229d4221272186597d9393f654adbb9 (patch) | |
tree | 2b3bdaf50f616769684ba2004d27fd78367e0280 /drivers/i2c/busses | |
parent | 05872b8039101867e7312c6c3a560b887b2d9079 (diff) | |
download | op-kernel-dev-9f4d6f164229d4221272186597d9393f654adbb9.zip op-kernel-dev-9f4d6f164229d4221272186597d9393f654adbb9.tar.gz |
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>
Diffstat (limited to 'drivers/i2c/busses')
-rw-r--r-- | drivers/i2c/busses/i2c-mv64xxx.c | 2 |
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); |