This is to fix a build warning in the Linux kernel caused by dtc
incorrectly warning about I2C_OWN_SLAVE_ADDRESS.
v4 adds a U to the defines
v3 fixes the 10 bit size check
v2 contains a second patch to check for 10 bit vs 7 bit addresses.
Joel Stanley (2):
checks: Remove warning for I2C_OWN_SLAVE_ADDRESS
checks: Improve i2c reg property checking
checks.c | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)
--
2.27.0
The i2c bindings in the kernel tree describe support for 10 bit
addressing, which must be indicated with the I2C_TEN_BIT_ADDRESS flag.
When this is set the address can be up to 10 bits. When it is not set
the address is a maximum of 7 bits.
See Documentation/devicetree/bindings/i2c/i2c.txt.
Take into account this flag when checking the address is valid.
Signed-off-by: Joel Stanley <[email protected]>
---
v2: Mask reg when checking the 10-bit size
v3: Fix test
v4: Add U to define
---
checks.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/checks.c b/checks.c
index 69b0156c940c..b7955dbd71ca 100644
--- a/checks.c
+++ b/checks.c
@@ -1023,6 +1023,7 @@ static void check_i2c_bus_bridge(struct check *c, struct dt_info *dti, struct no
WARNING(i2c_bus_bridge, check_i2c_bus_bridge, NULL, &addr_size_cells);
#define I2C_OWN_SLAVE_ADDRESS (1U << 30)
+#define I2C_TEN_BIT_ADDRESS (1U << 31)
static void check_i2c_bus_reg(struct check *c, struct dt_info *dti, struct node *node)
{
@@ -1057,10 +1058,13 @@ static void check_i2c_bus_reg(struct check *c, struct dt_info *dti, struct node
reg = fdt32_to_cpu(*(cells++));
/* Ignore I2C_OWN_SLAVE_ADDRESS */
reg &= ~I2C_OWN_SLAVE_ADDRESS;
- if (reg > 0x3ff)
+
+ if ((reg & I2C_TEN_BIT_ADDRESS) && ((reg & ~I2C_TEN_BIT_ADDRESS) > 0x3ff))
FAIL_PROP(c, dti, node, prop, "I2C address must be less than 10-bits, got \"0x%x\"",
reg);
-
+ else if (reg > 0x7f)
+ FAIL_PROP(c, dti, node, prop, "I2C address must be less than 7-bits, got \"0x%x\". Set I2C_TEN_BIT_ADDRESS for 10 bit addresses or fix the property",
+ reg);
}
}
WARNING(i2c_bus_reg, check_i2c_bus_reg, NULL, ®_format, &i2c_bus_bridge);
--
2.27.0
dtc does a sanity check on reg properties that they are within the 10
bit address range for i2c slave addresses. In the case of multi-master
buses or devices that act as a slave, the binding may describe an
address that the bus will listen on as a device. Do not warn when this
flag is set.
See Documentation/devicetree/bindings/i2c/i2c.txt.
This fixes the following build warnings reported by Stephen and by Arnd:
arch/arm/boot/dts/aspeed-bmc-facebook-yosemitev2.dts:126.11-130.4:
Warning (i2c_bus_reg): /ahb/apb/bus@1e78a000/i2c-bus@80/ipmb1@10:
I2C bus unit address format error, expected "40000010"
arch/arm/boot/dts/aspeed-bmc-facebook-yosemitev2.dts:128.3-30:
Warning (i2c_bus_reg): /ahb/apb/bus@1e78a000/i2c-bus@80/ipmb1@10:reg:
I2C address must be less than 10-bits, got "0x40000010"
Reported-by: Stephen Rothwell <[email protected]>
Reported-by: Arnd Bergmann <[email protected]>
Signed-off-by: Joel Stanley <[email protected]>
---
v2: Fix typo
v4: Add U to define
---
checks.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/checks.c b/checks.c
index a8213c0e13a8..69b0156c940c 100644
--- a/checks.c
+++ b/checks.c
@@ -1022,6 +1022,8 @@ static void check_i2c_bus_bridge(struct check *c, struct dt_info *dti, struct no
}
WARNING(i2c_bus_bridge, check_i2c_bus_bridge, NULL, &addr_size_cells);
+#define I2C_OWN_SLAVE_ADDRESS (1U << 30)
+
static void check_i2c_bus_reg(struct check *c, struct dt_info *dti, struct node *node)
{
struct property *prop;
@@ -1044,6 +1046,8 @@ static void check_i2c_bus_reg(struct check *c, struct dt_info *dti, struct node
}
reg = fdt32_to_cpu(*cells);
+ /* Ignore I2C_OWN_SLAVE_ADDRESS */
+ reg &= ~I2C_OWN_SLAVE_ADDRESS;
snprintf(unit_addr, sizeof(unit_addr), "%x", reg);
if (!streq(unitname, unit_addr))
FAIL(c, dti, node, "I2C bus unit address format error, expected \"%s\"",
@@ -1051,6 +1055,8 @@ 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++));
+ /* Ignore I2C_OWN_SLAVE_ADDRESS */
+ reg &= ~I2C_OWN_SLAVE_ADDRESS;
if (reg > 0x3ff)
FAIL_PROP(c, dti, node, prop, "I2C address must be less than 10-bits, got \"0x%x\"",
reg);
--
2.27.0
On Mon, Jun 22, 2020 at 12:40:03PM +0930, Joel Stanley wrote:
> This is to fix a build warning in the Linux kernel caused by dtc
> incorrectly warning about I2C_OWN_SLAVE_ADDRESS.
Applied, thanks.
>
> v4 adds a U to the defines
> v3 fixes the 10 bit size check
> v2 contains a second patch to check for 10 bit vs 7 bit addresses.
>
> Joel Stanley (2):
> checks: Remove warning for I2C_OWN_SLAVE_ADDRESS
> checks: Improve i2c reg property checking
>
> checks.c | 14 ++++++++++++--
> 1 file changed, 12 insertions(+), 2 deletions(-)
>
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson