On 08/01/2014 12:29, Wolfram Sang wrote:
> On Wed, Jan 08, 2014 at 11:15:05AM +0100, Gregory CLEMENT wrote:
>> Hi Wolfram,
>>
>> On 08/01/2014 00:06, Wolfram Sang wrote:
>>> On Tue, Jan 07, 2014 at 11:38:53AM -0700, Jason Gunthorpe wrote:
>>>> On Tue, Jan 07, 2014 at 05:35:03PM +0100, Gregory CLEMENT wrote:
>>>>> +static struct property i2c_offload_broken = {
>>>>> + .name = "offload-broken",
>>>>> +};
>>>>> +
>>>>> +static void __init i2c_quirk(void)
>>>>> +{
>>>>> + struct device_node *np;
>>>>> + u32 dev, rev;
>>>>> +
>>>>> + /*
>>>>> + * Only revisons more recent than A0 support the offload
>>>>> + * mechanism. We can exit only if we are sure that we can
>>>>> + * get the SoC revision and it is more recent than A0.
>>>>> + */
>>>>> + if (mvebu_get_soc_id(&rev, &dev) == 0 && dev > MV78XX0_A0_REV)
>>>>> + return;
>>>>> +
>>>>> + for_each_compatible_node(np, NULL, "marvell,mv78230-i2c")
>>>>> + of_add_property(np, &i2c_offload_broken);
>>>>
>>>> I like this approach.
>>>
>>> Sorry, but I don't.
>>>
>>>> However, when I first read this I thought it should be a -a0 specific
>>>> compatible string, not a 'offload-broken' property - any idea what the
>>>> DT consensus is here? I've seen both approach in use ..
>>>
>>> I prefer the replacement of the compatible string. If it should really
>>> be a seperate property, then it should be a vendor specific property. It
>>> is not generic, at all.
>>
>> Something like "marvell,offload-broken" would be acceptable?
>
> A tad more, yes. Still, since this is a feature/quirk of the IP core
> revision, it should be deduced from the compatible property IMO. It
> cannot be configured anywhere, so it doesn't change on board level.
So you would prefer using the "marvell,mv78230-a0-i2c" comaptible string and
updating it with the follwing piece of code?
diff --git a/arch/arm/mach-mvebu/armada-370-xp.c b/arch/arm/mach-mvebu/armada-370-xp.c
index e2acff98e750..8c4ecf987e82 100644
--- a/arch/arm/mach-mvebu/armada-370-xp.c
+++ b/arch/arm/mach-mvebu/armada-370-xp.c
@@ -21,6 +21,8 @@
#include <linux/clocksource.h>
#include <linux/dma-mapping.h>
#include <linux/mbus.h>
+#include <linux/mvebu-soc-id.h>
+#include <linux/slab.h>
#include <asm/hardware/cache-l2x0.h>
#include <asm/mach/arch.h>
#include <asm/mach/map.h>
@@ -45,8 +47,38 @@ static void __init armada_370_xp_timer_and_clk_init(void)
#endif
}
+static void __init i2c_quirk(void)
+{
+ struct device_node *np;
+ u32 dev, rev;
+ int i = 0;
+
+ /*
+ * Only revisons more recent than A0 support the offload
+ * mechanism. We can exit only if we are sure that we can
+ * get the SoC revision and it is more recent than A0.
+ */
+ if (mvebu_get_soc_id(&rev, &dev) == 0 && dev > MV78XX0_A0_REV)
+ return;
+
+ for_each_compatible_node(np, NULL, "marvell,mv78230-i2c") {
+ struct property *new_compat;
+
+ new_compat = kzalloc(sizeof(*new_compat), GFP_KERNEL);
+
+ new_compat->name = kstrdup("compatible", GFP_KERNEL);
+ new_compat->length = sizeof("marvell,mv78230-a0-i2c");
+ new_compat->value = kstrdup("marvell,mv78230-a0-i2c",
+ GFP_KERNEL);
+
+ of_update_property(np, new_compat);
+ }
+ return;
+}
+
static void __init armada_370_xp_dt_init(void)
{
+ i2c_quirk();
of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
}
>
>
>
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>
--
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com
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