Re: [PATCH] I2C: i.MX: early: Use internal udelay

[Ahmad Fatoum <a.fatoum@pengutronix.de>]

Hello Alexander,

On 01.02.23 18:50, Alexander Shiyan wrote:
> Hello!
> 
> Just a nitpick, udelay means milliseconds (udelay_(us)),
> which isn't quite right in this case,
> so I think we should use the "loops" value here (delay_loops() or so)).

udelay is already defined used ARMv8 architected timer, so what John is
doingvis providing an implementation for i.MX6. So even if it uses a loop,
the iterations are chosen to be roughly the amount of microseconds
in the argument and thus the name is ok IMO. See his latest revision
of the patch.

Cheers,
Ahmad

> 
> Thanks!
> 
> чт, 26 янв. 2023 г. в 21:57, John Watts <contact@jookia.org>:
>>
>> udelay isn't provided in the PBL, so use our own definition.
>>
>> This avoids boards having to define udelay in their code.
>>
>> Signed-off-by: John Watts <contact@jookia.org>
>> ---
>>  drivers/i2c/busses/i2c-imx-early.c | 9 ++++++++-
>>  1 file changed, 8 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/i2c/busses/i2c-imx-early.c b/drivers/i2c/busses/i2c-imx-early.c
>> index 6c8bdc7904..fcf279eff8 100644
>> --- a/drivers/i2c/busses/i2c-imx-early.c
>> +++ b/drivers/i2c/busses/i2c-imx-early.c
>> @@ -90,6 +90,13 @@ static int i2c_fsl_acked(struct fsl_i2c *fsl_i2c)
>>         return i2c_fsl_poll_status(fsl_i2c, 0, I2SR_RXAK);
>>  }
>>
>> +static void __udelay(int us)
>> +{
>> +       volatile int i;
>> +
>> +       for (i = 0; i < us * 1000; i++);
>> +}
>> +
>>  static int i2c_fsl_start(struct fsl_i2c *fsl_i2c)
>>  {
>>         unsigned int temp = 0;
>> @@ -104,7 +111,7 @@ static int i2c_fsl_start(struct fsl_i2c *fsl_i2c)
>>                           fsl_i2c, FSL_I2C_I2CR);
>>
>>         /* Wait controller to be stable */
>> -       udelay(100);
>> +       __udelay(100);
>>
>>         /* Start I2C transaction */
>>         temp = fsl_i2c_read_reg(fsl_i2c, FSL_I2C_I2CR);
>> --
>> 2.39.1
>>
>>
> 
> 

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