Re: [PATCH v1 1/1] scripts: dtc: mask flags bit when check i2c addr

From: Rob Herring
Date: Fri Feb 28 2020 - 08:50:13 EST


On Fri, Feb 28, 2020 at 2:48 AM Rayagonda Kokatanur
<rayagonda.kokatanur@xxxxxxxxxxxx> wrote:
>
> Generally i2c addr should not be greater than 10-bit. The highest 2 bits
> are used for I2C_TEN_BIT_ADDRESS and I2C_OWN_SLAVE_ADDRESS. Need to mask
> these flags if check slave addr valid.
>
> Signed-off-by: Rayagonda Kokatanur <rayagonda.kokatanur@xxxxxxxxxxxx>
> ---
> scripts/dtc/Makefile | 2 +-
> scripts/dtc/checks.c | 5 +++++
> 2 files changed, 6 insertions(+), 1 deletion(-)

dtc changes must be submitted against upstream dtc.


> diff --git a/scripts/dtc/Makefile b/scripts/dtc/Makefile
> index 3acbb410904c..c5e8d6a9e73c 100644
> --- a/scripts/dtc/Makefile
> +++ b/scripts/dtc/Makefile
> @@ -9,7 +9,7 @@ dtc-objs := dtc.o flattree.o fstree.o data.o livetree.o treesource.o \
> dtc-objs += dtc-lexer.lex.o dtc-parser.tab.o
>
> # Source files need to get at the userspace version of libfdt_env.h to compile
> -HOST_EXTRACFLAGS := -I $(srctree)/$(src)/libfdt
> +HOST_EXTRACFLAGS := -I $(srctree)/$(src)/libfdt -I$(srctree)/tools/include
>
> ifeq ($(shell pkg-config --exists yaml-0.1 2>/dev/null && echo yes),)
> ifneq ($(CHECK_DTBS),)
> diff --git a/scripts/dtc/checks.c b/scripts/dtc/checks.c
> index 756f0fa9203f..17c9ed4137b5 100644
> --- a/scripts/dtc/checks.c
> +++ b/scripts/dtc/checks.c
> @@ -3,6 +3,7 @@
> * (C) Copyright David Gibson <dwg@xxxxxxxxxxx>, IBM Corporation. 2007.
> */
>
> +#include <linux/bits.h>

Not a UAPI header not that that would be much better as dtc also builds on Mac.

> #include "dtc.h"
> #include "srcpos.h"
>
> @@ -17,6 +18,9 @@
> #define TRACE(c, fmt, ...) do { } while (0)
> #endif
>
> +#define I2C_TEN_BIT_ADDRESS BIT(31)
> +#define I2C_OWN_SLAVE_ADDRESS BIT(30)
> +
> enum checkstatus {
> UNCHECKED = 0,
> PREREQ,
> @@ -1048,6 +1052,7 @@ static void check_i2c_bus_reg(struct check *c, struct dt_info *dti, struct node
>
> for (len = prop->val.len; len > 0; len -= 4) {
> reg = fdt32_to_cpu(*(cells++));
> + reg &= ~(I2C_OWN_SLAVE_ADDRESS | I2C_TEN_BIT_ADDRESS);

I'd just mask the top byte so we don't have to update on the next flag we add.

Rob