[PATCH v4 2/2] checks: Improve i2c reg property checking

[Joel Stanley]

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 <j...@jms.id.au>
---
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, &reg_format, &i2c_bus_bridge);
-- 
2.27.0