[PATCH v3 2/2] checks: Improve i2c reg property checking

From: Joel Stanley
Date: Thu May 28 2020 - 04:57:14 EST


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)

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);
--
2.26.2