On Thu, May 28, 2020 at 06:26:50PM +0930, Joel Stanley wrote: > 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 <joel@xxxxxxxxx> > --- > v2: Mask reg when checking the 10-bit size > --- > checks.c | 8 ++++++-- > 1 file changed, 6 insertions(+), 2 deletions(-) > > diff --git a/checks.c b/checks.c > index feb1721f2603..3fe979a63290 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 (1 << 30) > +#define I2C_TEN_BIT_ADDRESS (1 << 31) As Andy neatly pointed out here: https://lore.kernel.org/lkml/20200527133656.GV1634618@xxxxxxxxxxxxxxxxxx/ (1 << 31) is UB. -Sergey > > 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); > -- > 2.26.2 >
