Re: [PATCH 1/1] i2c: qcom-geni: add 32MHz I2C SE clock support for IPQ5424

Mukesh Kumar Savaliya
2024-09-25T09:55:21Z

Thanks manikanta !

On 9/25/2024 2:14 PM, Manikanta Mylavarapu wrote:
>
>
> On 9/25/2024 1:06 PM, Mukesh Kumar Savaliya wrote:
>> Hi Manikanta,
>>
>> On 9/24/2024 12:20 PM, Manikanta Mylavarapu wrote:
>>> The IPQ5424 I2C SE clock operates at a frequency of 32MHz. Since the
>> would it be better to say , I2C SE is sourced from 32MHZ ?
>
> Okay, sure.
>
>>> existing map table is based on 19.2MHz, this patch incorporate the
>> based on 19.2MHz. this patch /,/.
>
> Okay, sure.
>
>>> clock map table to derive the SCL clock from the 32MHz SE clock.
>> from the 32MHz Source Clock frequency.
>> SE = Expand OR  (I2C Serial Engine Controller)
>
> Okay, sure.
>
Please also mention the reason why 32MHz got added ? Need to describe
evolution to understand the purpose behind this change.
>>>
>>> Signed-off-by: Manikanta Mylavarapu <quic_mmanikan@quicinc.com>
>>> ---
>>>   drivers/i2c/busses/i2c-qcom-geni.c | 11 +++++++++++
>>>   1 file changed, 11 insertions(+)
>>>
>>> diff --git a/drivers/i2c/busses/i2c-qcom-geni.c b/drivers/i2c/busses/i2c-qcom-geni.c
>>> index 212336f724a6..bbd9ecf09f4b 100644
>>> --- a/drivers/i2c/busses/i2c-qcom-geni.c
>>> +++ b/drivers/i2c/busses/i2c-qcom-geni.c
>>> @@ -71,6 +71,7 @@ enum geni_i2c_err_code {
>>>     #define I2C_AUTO_SUSPEND_DELAY    250
>>>   #define KHZ(freq)        (1000 * freq)
>>> +#define MHZ(freq)        (1000000 * freq)
>>>   #define PACKING_BYTES_PW    4
>>>     #define ABORT_TIMEOUT        HZ
>>> @@ -152,11 +153,21 @@ static const struct geni_i2c_clk_fld geni_i2c_clk_map[] = {
>> A thought - Should we rename this appending _19.2M ? In future one or more may come as it evolves speed.
>
> Okay, sure.
>
> Thanks & Regards,
> Manikanta.
>
>>>       {KHZ(1000), 1, 3,  9, 18},
>>>   };
>>>   +/* source_clock = 32 MHz */
>>> +static const struct geni_i2c_clk_fld geni_i2c_clk_map_32M[] = {
>>> +    {KHZ(100), 7, 14, 18, 40},
>>> +    {KHZ(400), 4,  3, 11, 20},
>>> +    {KHZ(1000), 4, 3,  6, 15},
>>> +};
>>> +
>>>   static int geni_i2c_clk_map_idx(struct geni_i2c_dev *gi2c)
>>>   {
>>>       int i;
>>>       const struct geni_i2c_clk_fld *itr = geni_i2c_clk_map;
>>>   +    if (clk_get_rate(gi2c->se.clk) == MHZ(32))
>>> +        itr = geni_i2c_clk_map_32M;
>>> +
>>>       for (i = 0; i < ARRAY_SIZE(geni_i2c_clk_map); i++, itr++) {
>>>           if (itr->clk_freq_out == gi2c->clk_freq_out) {
>>>               gi2c->clk_fld = itr;
>