Commit graph

3 commits

Author SHA1 Message Date
Lukasz Majewski
a40fe217d1 DM: I2C: Introduce 'u-boot, i2c-transaction-bytes' property
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 <lukma@denx.de>
2019-04-11 15:21:33 +02:00
Alexander Kochetkov
df8dcac8a3 dm: i2c: dts: Add gpios and pinctrl device tree properties
The commit describe usage of gpios and pinctrl device tree
properties in order to enable gpio-based software deblocking.

Signed-off-by: Alexander Kochetkov <al.kochet@gmail.com>
2018-04-11 11:34:17 +02:00
Simon Glass
7132b9fd68 dm: i2c: dts: Support an offset-len device tree property
Since U-Boot can support different offset lengths (0-4 bytes), add a device
tree property to specify this. This avoids hard-coding it in the driver.

Signed-off-by: Simon Glass <sjg@chromium.org>
2015-01-29 17:10:01 -07:00