Also we can enable m24c02 eeprom chip in dts-file e.g.
&i2c0 {
status = "okay";
eeprom: m24c02@50 {
compatible = "spd";
reg = <0x50>;
};
};
Alas! qemu mips malta spd m24c02 eeprom chip emulation is not perfect:
the block read operation does not work properly.
Here is an example.
If we read eeprom content byte-by-byte then there is no problem:
barebox:/ for i in 0x08 0x09 0x0a 0x0b 0x0c 0x0d 0x0e 0x0f ;
> do i2c_read -b 0 -a 0x50 -r $i -c 1 ; done
0x01
0x75
0x54
0x00
0x82
0x08
0x00
0x01
Compare this output with content of qemu.git/hw/mips/mips_malta.c:
static eeprom24c0x_t spd_eeprom = {
.contents = {
...
/* 00000008: */ 0x01,0x75,0x54,0x00,0x82,0x08,0x00,0x01,
But if we read several bytes at once the we have data corruption:
barebox:/ i2c_read -b 0 -a 0x50 -r 0x8 -c 8
0x01 0xff 0xff 0xff 0xff 0xff 0xff 0xff
Signed-off-by: Antony Pavlov <[email protected]>
---
arch/mips/dts/qemu-malta.dts | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/arch/mips/dts/qemu-malta.dts b/arch/mips/dts/qemu-malta.dts
index 204007d..cc1c960 100644
--- a/arch/mips/dts/qemu-malta.dts
+++ b/arch/mips/dts/qemu-malta.dts
@@ -32,6 +32,18 @@
#gpio-cells = <2>;
};
+ i2c0: i2c0 {
+ compatible = "i2c-gpio";
+ gpios = <&gpio 0 0 /* sda */
+ &gpio 1 0 /* scl */
+ >;
+ i2c-gpio,sda-open-drain;
+ i2c-gpio,scl-open-drain;
+ #address-cells = <1>;
+ #size-cells = <0>;
+ status = "disabled";
+ };
+
uart2: serial@bf000900 {
compatible = "ns16550a";
reg = <0xbf000900 0x40>;
@@ -58,3 +70,7 @@
};
};
};
+
+&i2c0 {
+ status = "okay";
+};
--
1.9.2
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