[U-Boot] [PATCH] i2c: designware: Get clock rate from clock DM

[Marek Vasut]

On 6/10/19 8:07 AM, Ley Foon Tan wrote:
[...]

>>>> [...]
>>>>
>>>>> @@ -523,8 +527,20 @@ static int designware_i2c_xfer(struct udevice *bus, struct i2c_msg *msg,
>>>>>  static int designware_i2c_set_bus_speed(struct udevice *bus, unsigned int speed)
>>>>>  {
>>>>>       struct dw_i2c *i2c = dev_get_priv(bus);
>>>>> +     ulong rate;
>>>>> +
>>>>> +#if CONFIG_IS_ENABLED(CLK)
>>>>> +     rate = clk_get_rate(&i2c->clk);
>>>>
>>>> Do we need to re-read the bus frequency for each transfer ?
>>>> I would expect set_bus_speed callback to set the frequencies once and
>>>> then keep them that way until it's called again.
>>> Yes, we can get clock rate when request clock in _probe(). Then keep a
>>> copy for future use.
>>
>> Not in .probe() , in set_bus_speed().
> My patch is doing it in designware_i2c_set_bus_speed() already.  We
> can't get clock rate in __dw_i2c_set_bus_speed(), because this
> function doesn't have struct udevice.

include/i2c.h struct dm_i2c_ops {} :

388         /**
389          * set_bus_speed() - set the speed of a bus (optional)
390          *
391          * The bus speed value will be updated by the uclass if this
function
392          * does not return an error. This method is optional - if it
is not
393          * provided then the driver can read the speed from
394          * dev_get_uclass_priv(bus)->speed_hz
395          *
396          * @bus:        Bus to adjust
397          * @speed:      Requested speed in Hz
398          * @return 0 if OK, -EINVAL for invalid values
399          */
400         int (*set_bus_speed)(struct udevice *bus, unsigned int speed);

There's struct udevice right there ^

-- 
Best regards,
Marek Vasut