I2C node in device tree breaks old-style drivers
Jochen Friedrich
jochen at scram.de
Wed Jul 30 20:54:27 EST 2008
Hi Timur,
> So my conclusion is that specifying an I2C node in the device tree *requires*
> that the driver be new-style. Is there any way we can fix this? I'm not going
> to have time to update the CS4270 driver to a new-style interface before the
> 2.6.27 window closes.
This conclusion is correct. One possible way to fix this is to add support for
blacklisting to drivers/of/base.c (untested):
[RFC] of: Support blacklisting and blacklist cs4270.
Signed-off-by: Jochen Friedrich <jochen at scram.de>
---
drivers/of/base.c | 8 +++++++-
1 files changed, 7 insertions(+), 1 deletions(-)
diff --git a/drivers/of/base.c b/drivers/of/base.c
index ad8ac1a..8c53b2c 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -404,13 +404,16 @@ EXPORT_SYMBOL(of_find_matching_node);
* assumed that the data size is small and that the compatible values
* should already be distinct enough to differentiate between SPI, I2C
* and other devices.
+ *
+ * Blacklisting devices is supported by using NULL as modalias.
*/
struct of_modalias_table {
char *of_device;
char *modalias;
};
static struct of_modalias_table of_modalias_table[] = {
- /* Empty for now; add entries as needed */
+ /* Blacklisting cs4270 as this driver is currently old-style. */
+ { "cirrus,cs4270", NULL }
};
/**
@@ -441,6 +444,9 @@ int of_modalias_node(struct device_node *node, char *modalias, int len)
compatible = of_modalias_table[i].of_device;
if (!of_device_is_compatible(node, compatible))
continue;
+ /* Check for blacklisting */
+ if (!of_modalias_table[i].modalias)
+ return -ENODEV;
strlcpy(modalias, of_modalias_table[i].modalias, len);
return 0;
}
--
1.5.6.3
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