| Message ID | 1436214373-12969-2-git-send-email-pali.rohar@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
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.rohar@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.
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.rohar@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
On Monday 28 December 2015 13:01:22 Frank Rowand wrote: > > 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. Agreed. That would be simpler, and avoid a situation where someone relies on the /revision property in DT to be set from the atags compat code (preventing an upgrade to a newer bootloader), or on the system_rev variable to be the same across multiple boot loaders, in the absence of other kernel code setting it. Arnd
On Monday 28 December 2015 23:27:17 Arnd Bergmann wrote: > On Monday 28 December 2015 13:01:22 Frank Rowand wrote: > > > > 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. > > Agreed. That would be simpler, and avoid a situation where someone relies > on the /revision property in DT to be set from the atags compat code > (preventing an upgrade to a newer bootloader), or on the system_rev variable > to be the same across multiple boot loaders, in the absence of other > kernel code setting it. So, set system_rev only for Nokia N900? At same place where is called save_atags()?
On Tuesday 05 January 2016 12:37:50 Pali Rohár wrote: > On Monday 28 December 2015 23:27:17 Arnd Bergmann wrote: > > On Monday 28 December 2015 13:01:22 Frank Rowand wrote: > > > > > > 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. > > > > Agreed. That would be simpler, and avoid a situation where someone relies > > on the /revision property in DT to be set from the atags compat code > > (preventing an upgrade to a newer bootloader), or on the system_rev variable > > to be the same across multiple boot loaders, in the absence of other > > kernel code setting it. > > So, set system_rev only for Nokia N900? At same place where is called > save_atags()? > > Yes. Arnd
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; }
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.rohar@gmail.com> --- arch/arm/kernel/devtree.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-)