Hello Lukasz,
Am 04.04.2019 um 12:35 schrieb Lukasz Majewski:
The 'u-boot,i2c-transaction-bytes' device tree property provides
information regarding number of bytes transferred by a device in a
single transaction.
This change is necessary to avoid hanging devices after soft reset.
One notable example is communication with MC34708 device:
1. Reset when communicating with MC34708 via I2C.
2. The u-boot (after reboot -f) tries to setup the I2C and then calls
force_idle_bus. In the same time MC34708 still has some data to be sent
(as it transfers data in 24 bits chunks).
3. The force_idle_bus() is not able to make the bus idle as 8 SCL
clocks may be not enough to have the full transmission.
4. We end up with I2C inconsistency with MC34708.
This PMIC device requires 24+ SCL cycles to make finish any pending I2C
transmission.
Signed-off-by: Lukasz Majewski <lu...@denx.de>
---
doc/device-tree-bindings/i2c/i2c.txt | 5 +++++
drivers/i2c/i2c-uclass.c | 24 ++++++++++++++++++++++++
drivers/i2c/mxc_i2c.c | 19 +++++++++++++++++--
include/i2c.h | 2 ++
4 files changed, 48 insertions(+), 2 deletions(-)
Reviewed-by: Heiko Schocher<h...@denx.de>
bye,
Heiko
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