[PATCH v2] i2c: designware_i2c: adjust timing calculation

[Heiko Schocher]

Hello Heinrich,

On 13.10.23 15:09, Heinrich Schuchardt wrote:
> In SPL probing of the designware_i2c device on the StarFive VisionFive 2
> board fails with
> 
>     dw_i2c: mode 0, ic_clk 1000000, speed 100000,
>     period 10 rise 1 fall 1 tlow 5 thigh 4 spk 0
>     dw_i2c: bad counts. hcnt = -4 lcnt = 4
>     device_probe: i2c at 12050000 failed to probe -22
> 
> When changing the offset for the high phase from 7 to 3 the device is
> probed correctly. This now matches the value from the Linux driver.
> 
> Without this fix the memory size of the StarFive VisionFive 2 board cannot
> be read from EEPROM.
> 
> Fixes: e71b6f6622d6 ("i2c: designware_i2c: Rewrite timing calculation")
> 
> Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt at canonical.com>
> ---
> v2:
> 	use the same timing offset at Linux
> 	provide a descriptive comment for the constant
> ---
>  drivers/i2c/designware_i2c.c | 19 +++++++++++++++----
>  1 file changed, 15 insertions(+), 4 deletions(-)

Many thanks for this update!

Reviewed-by: Heiko Schocher <hs at denx.de>

bye,
Heiko
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