Two variants of controllers are supported:
V1 (bitwise only) found in
i.MX21, i.MX27, i.MX31, i.MX51
V2 (byte operations) found in
i.MX25, i.MX35, i.MX50, i.MX53
Only tested on i.MX53 hardware but in both modes
(by modifying the device tree).
Signed-off-by: Martin Fuzzey <martin.fuzzey@flowbird.group>
Sometimes enumeration fails (about 1 in 50 times on my custom board).
The underlying reason is probably electrical but Linux does not have
the problem.
Comparing the Linux / u-boot implementations shows that Linux
retries the error case whereas u-boot aborts early.
Removing the early abort in u-boot fixes the problem.
Signed-off-by: Martin Fuzzey <martin.fuzzey@flowbird.group>
When the "w1 bus" command is used with no bus master present
a data abort may occur.
This is because uclass_first_device() returns zero, but sets the output
struct udevice pointer to NULL in the no device found case.
Fix w1_get_bus() to account for this and return an error code
as is expected by the callers.
Signed-off-by: Martin Fuzzey <martin.fuzzey@flowbird.group>
Reviewed-by: Eugen Hristev <eugen.hristev@microchip.com>
When a new device is discovered, this may be a w1 eeprom device.
Attempt to find the proper node and driver from the w1-eeprom subsystem.
Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Add a bus driver for bitbanging a 1-Wire bus over a GPIO.
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
[eugen.hristev@microchip.com: fixed some issues]
Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
We might want to use 1-Wire devices connected on boards such as EEPROMs in
U-Boot.
Provide a framework to be able to do that.
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
[eugen.hristev@microchip.com: reworked]
Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
