Adding devicetree-spec, and commenting below.
On 12/24/2015 11:02 AM, Pali Rohár wrote:
> On Monday 06 July 2015 22:26:09 Pali Rohár wrote:
>> With this patch "/revision" DT entry is used to set global system_rev
>> variable. DT "/revision" is expected to be u32 numeric value.
>>
>> TODO: add documentation
>>
>> Signed-off-by: Pali Rohár <pali.ro...@gmail.com>
>> ---
>> arch/arm/kernel/devtree.c | 12 ++++++++++--
>> 1 file changed, 10 insertions(+), 2 deletions(-)
>>
>> diff --git a/arch/arm/kernel/devtree.c b/arch/arm/kernel/devtree.c
>> index 11c54de..7d82749 100644
>> --- a/arch/arm/kernel/devtree.c
>> +++ b/arch/arm/kernel/devtree.c
>> @@ -19,6 +19,7 @@
>> #include <linux/of_irq.h>
>> #include <linux/of_platform.h>
>> #include <linux/smp.h>
>> +#include <linux/libfdt_env.h>
>>
>> #include <asm/cputype.h>
>> #include <asm/setup.h>
>> @@ -26,6 +27,7 @@
>> #include <asm/smp_plat.h>
>> #include <asm/mach/arch.h>
>> #include <asm/mach-types.h>
>> +#include <asm/system_info.h>
>>
>>
>> #ifdef CONFIG_SMP
>> @@ -204,6 +206,8 @@ static const void * __init arch_get_next_mach(const char
>> *const **match)
>> const struct machine_desc * __init setup_machine_fdt(unsigned int dt_phys)
>> {
>> const struct machine_desc *mdesc, *mdesc_best = NULL;
>> + unsigned long dt_root;
>> + const u32 *rev;
>>
>> #ifdef CONFIG_ARCH_MULTIPLATFORM
>> DT_MACHINE_START(GENERIC_DT, "Generic DT based system")
>> @@ -215,17 +219,16 @@ const struct machine_desc * __init
>> setup_machine_fdt(unsigned int dt_phys)
>> if (!dt_phys || !early_init_dt_verify(phys_to_virt(dt_phys)))
>> return NULL;
>>
>> + dt_root = of_get_flat_dt_root();
>> mdesc = of_flat_dt_match_machine(mdesc_best, arch_get_next_mach);
>>
>> if (!mdesc) {
>> const char *prop;
>> int size;
>> - unsigned long dt_root;
>>
>> early_print("\nError: unrecognized/unsupported "
>> "device tree compatible list:\n[ ");
>>
>> - dt_root = of_get_flat_dt_root();
>> prop = of_get_flat_dt_prop(dt_root, "compatible", &size);
>> while (size > 0) {
>> early_print("'%s' ", prop);
>> @@ -246,5 +249,10 @@ const struct machine_desc * __init
>> setup_machine_fdt(unsigned int dt_phys)
>> /* Change machine number to match the mdesc we're using */
>> __machine_arch_type = mdesc->nr;
>>
>> + /* Set system revision from DT */
>> + rev = of_get_flat_dt_prop(dt_root, "revision", NULL);
>> + if (rev)
>> + system_rev = fdt32_to_cpu(*rev);
>> +
>> return mdesc;
>> }
>
> This patch and second one (with subject "[PATCH 2/5] arm: boot: convert
> ATAG_REVISION to DT "/revision" entry") are still needed.
>
> Are there any objections for them? If not, I will add missing DT
> documentation and will resend them.
Patch 2/5 copies the value from ATAG_REVISION into the fdt "/revision"
property.
If the use of /revision is limited to being a location to hold an ATAG
value to pass to the global variable system_rev, then it would make
sense to just copy directly from the ATAG value into system_rev in the
same board file where you are copying the ATAGs.
-Frank
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