Re: [PATCH 08/20] interconnect: qcom: smd-rpm: Add rpmcc handling skeleton code

[Konrad Dybcio <konrad.dybcio@linaro.org>]

On 1.06.2023 12:01, Dmitry Baryshkov wrote:
> On 30/05/2023 13:20, Konrad Dybcio wrote:
>> Introduce qcom_icc_rpm_set_bus_rate() in preparation for handling RPM
>> clock resources within the interconnect framework. This lets us greatly
>> simplify all of the code handling, as setting the rate comes down to:
>>
>> u32 rate_khz = max(clk.sleep_rate, clk.active_rate, clk_a.active_rate)
>> write_to_rpm(clock.description, rate_khz);
>>
>> Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
>> ---
>>   drivers/interconnect/qcom/icc-rpm.h | 15 +++++++++++++++
>>   drivers/interconnect/qcom/smd-rpm.c | 37 +++++++++++++++++++++++++++++++++++++
>>   2 files changed, 52 insertions(+)
>>
>> diff --git a/drivers/interconnect/qcom/icc-rpm.h b/drivers/interconnect/qcom/icc-rpm.h
>> index 9b4ea4e39b9f..aec192321411 100644
>> --- a/drivers/interconnect/qcom/icc-rpm.h
>> +++ b/drivers/interconnect/qcom/icc-rpm.h
>> @@ -22,6 +22,18 @@ enum qcom_icc_type {
>>       QCOM_ICC_QNOC,
>>   };
>>   +/**
>> + * struct rpm_clk_resource - RPM bus clock resource
>> + * @resource_type: RPM resource type of the clock resource
>> + * @clock_id: index of the clock resource of a specific resource type
>> + * @branch: whether the resource represents a branch clock
>> +*/
>> +struct rpm_clk_resource {
>> +    u32 resource_type;
>> +    u32 clock_id;
>> +    bool branch;
>> +};
>> +
>>   #define NUM_BUS_CLKS    2
>>     /**
>> @@ -47,6 +59,7 @@ struct qcom_icc_provider {
>>       int qos_offset;
>>       u64 bus_clk_rate[NUM_BUS_CLKS];
>>       struct clk_bulk_data bus_clks[NUM_BUS_CLKS];
>> +    const struct rpm_clk_resource *bus_clk_desc;
>>       struct clk_bulk_data *intf_clks;
>>       bool keep_alive;
>>       bool is_on;
>> @@ -104,6 +117,7 @@ struct qcom_icc_desc {
>>       struct qcom_icc_node * const *nodes;
>>       size_t num_nodes;
>>       const char * const *bus_clocks;
>> +    const struct rpm_clk_resource *bus_clk_desc;
>>       const char * const *intf_clocks;
>>       size_t num_intf_clocks;
>>       bool keep_alive;
>> @@ -125,5 +139,6 @@ int qnoc_remove(struct platform_device *pdev);
>>     bool qcom_icc_rpm_smd_available(void);
>>   int qcom_icc_rpm_smd_send(int ctx, int rsc_type, int id, u32 val);
>> +int qcom_icc_rpm_set_bus_rate(const struct rpm_clk_resource *clk, u32 active_rate, u32 sleep_rate);
>>     #endif
>> diff --git a/drivers/interconnect/qcom/smd-rpm.c b/drivers/interconnect/qcom/smd-rpm.c
>> index b0183262ba66..6c51e346b326 100644
>> --- a/drivers/interconnect/qcom/smd-rpm.c
>> +++ b/drivers/interconnect/qcom/smd-rpm.c
>> @@ -16,6 +16,7 @@
>>   #include "icc-rpm.h"
>>     #define RPM_KEY_BW        0x00007762
>> +#define QCOM_RPM_SMD_KEY_RATE    0x007a484b
> 
> Nit: can we move all RPM keys to some common header?
They're quite scattered across subsystems so I think it'd be a separate
topic.. Also I think we could think about migrating to stringified raw
values like we have in RPMh - they keys are LE 4-char, non-NULL-terminated
strings (e.g. this one is 'KHz')

> 
>>     static struct qcom_smd_rpm *icc_smd_rpm;
>>   @@ -44,6 +45,38 @@ int qcom_icc_rpm_smd_send(int ctx, int rsc_type, int id, u32 val)
>>   }
>>   EXPORT_SYMBOL_GPL(qcom_icc_rpm_smd_send);
>>   +int qcom_icc_rpm_set_bus_rate(const struct rpm_clk_resource *clk, u32 active_rate, u32 sleep_rate)
>> +{
>> +    struct clk_smd_rpm_req req = {
>> +        .key = cpu_to_le32(QCOM_RPM_SMD_KEY_RATE),
>> +        .nbytes = cpu_to_le32(sizeof(u32)),
>> +    };
>> +    int ret;
>> +
>> +    /* Branch clocks are only on/off */
>> +    if (clk->branch) {
>> +        active_rate = !!active_rate;
>> +        sleep_rate = !!sleep_rate;
>> +    }
>> +
>> +    req.value = cpu_to_le32(active_rate);
>> +    ret = qcom_rpm_smd_write(icc_smd_rpm,
>> +                 QCOM_SMD_RPM_ACTIVE_STATE,
>> +                 clk->resource_type,
>> +                 clk->clock_id,
>> +                 &req, sizeof(req));
>> +    if (ret)
>> +        return ret;
>> +
>> +    req.value = cpu_to_le32(sleep_rate);
>> +    return qcom_rpm_smd_write(icc_smd_rpm,
>> +                  QCOM_SMD_RPM_SLEEP_STATE,
>> +                  clk->resource_type,
>> +                  clk->clock_id,
>> +                  &req, sizeof(req));
>> +}
>> +EXPORT_SYMBOL_GPL(qcom_icc_rpm_set_bus_rate);
>> +
>>   static int qcom_icc_rpm_smd_remove(struct platform_device *pdev)
>>   {
>>       icc_smd_rpm = NULL;
>> @@ -60,6 +93,10 @@ static int qcom_icc_rpm_smd_probe(struct platform_device *pdev)
>>           return -ENODEV;
>>       }
>>   +    /* We need the clock driver to kick things off first to avoid ugly races */
>> +    if (!qcom_smd_rpm_scaling_available())
>> +        return -EPROBE_DEFER;
> 
> 
> This should not be a part of this commit.
"eeh", it makes no functional difference, as if this patch is the HEAD,
we're still consuming the clocks via CCF, which guarantees this is always
true.. I can move it if you wish.

Konrad
> 
>> +
>>       return 0;
>>   }
>>  
>