Re: [PATCH 5/8] OPP: Allow multiple clocks for a device

Krzysztof Kozlowski
2022-06-30T12:39:50Z

On 30/06/2022 14:32, Krzysztof Kozlowski wrote:
> On 10/06/2022 10:20, Viresh Kumar wrote:
>> This patch adds support to allow multiple clocks for a device.
>>
>> The design is pretty much similar to how this is done for regulators,
>> and platforms can supply their own version of the config_clks() callback
>> if they have multiple clocks for their device. The core manages the
>> calls via opp_table->config_clks() eventually.
>>
>> We have kept both "clk" and "clks" fields in the OPP table structure and
>> the reason is provided as a comment in _opp_set_clknames(). The same
>> isn't done for "rates" though and we use rates[0] at most of the places
>> now.
>>
>> Co-developed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
>> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
>> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
>
> (...)
>
>> + rates = kmalloc_array(count, sizeof(*rates), GFP_KERNEL);
>> + if (!rates)
>> + return -ENOMEM;
>> +
>> + ret = of_property_read_u64_array(np, "opp-hz", rates, count);
>> + if (ret) {
>> + pr_err("%s: Error parsing opp-hz: %d\n", __func__, ret);
>> + } else {
>> + /*
>> + * Rate is defined as an unsigned long in clk API, and so
>> + * casting explicitly to its type. Must be fixed once rate is 64
>> + * bit guaranteed in clk API.
>> + */
>> + for (i = 0; i < count; i++) {
>> + new_opp->rates[i] = (unsigned long)rates[i];
>> +
>> + /* This will happen for frequencies > 4.29 GHz */
>> + WARN_ON(new_opp->rates[i] != rates[i]);
>> + }
>> + }
>> +
>> + kfree(rates);
>> +
>> + return ret;
>> +}
>> +
>> static int _read_bw(struct dev_pm_opp *new_opp, struct opp_table *opp_table,
>> struct device_node *np, bool peak)
>> {
>> @@ -812,19 +859,13 @@ static int _read_opp_key(struct dev_pm_opp *new_opp,
>> struct opp_table *opp_table, struct device_node *np)
>> {
>> bool found = false;
>> - u64 rate;
>> int ret;
>>
>> - ret = of_property_read_u64(np, "opp-hz", &rate);
>> - if (!ret) {
>> - /*
>> - * Rate is defined as an unsigned long in clk API, and so
>> - * casting explicitly to its type. Must be fixed once rate is 64
>> - * bit guaranteed in clk API.
>> - */
>> - new_opp->rate = (unsigned long)rate;
>> + ret = _read_rate(new_opp, opp_table, np);
>> + if (ret)
>> + return ret;
>> + else if (opp_table->clk_count == 1)
>
> Shouldn't this be >=1? I got several clocks and this one fails.

Actually this might be correct, but you need to update the bindings. Now
you require opp-level for case with multiple clocks.

Best regards,
Krzysztof