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 <sfr@xxxxxxxxxxxxxxxx> Reported-by: Arnd Bergmann <arnd@xxxxxxxx> Signed-off-by: Joel Stanley <joel@xxxxxxxxx> --- 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