Re: [PATCH 1/7] soc: amlogic: clk-measure: Define MSR_CLK's register offset separately

[Chuan Liu <chuan.liu@amlogic.com>]

Hi Neil:

     Thanks for your suggestion.


On 4/11/2025 9:31 PM, Neil Armstrong wrote:
> [ EXTERNAL EMAIL ]
>
> Hi,
>
> On 11/04/2025 14:42, Chuan Liu via B4 Relay wrote:
>> From: Chuan Liu <chuan.liu@amlogic.com>
>>
>> Since the MSR_CLK register offset differs between chip variants, we
>> replace the macro-based definition with chip-specific assignments.
>>
>> Change the max_register in regmap_config to be retrieved from DTS.
>>
>> Signed-off-by: Chuan Liu <chuan.liu@amlogic.com>
>> ---
>>   drivers/soc/amlogic/meson-clk-measure.c | 70 
>> ++++++++++++++++++++++++++-------
>>   1 file changed, 55 insertions(+), 15 deletions(-)
>>
>> diff --git a/drivers/soc/amlogic/meson-clk-measure.c 
>> b/drivers/soc/amlogic/meson-clk-measure.c
>> index 39638d6a593c..30387d26307c 100644
>> --- a/drivers/soc/amlogic/meson-clk-measure.c
>> +++ b/drivers/soc/amlogic/meson-clk-measure.c
>> @@ -14,11 +14,6 @@
>>
>>   static DEFINE_MUTEX(measure_lock);
>>
>> -#define MSR_CLK_DUTY         0x0
>> -#define MSR_CLK_REG0         0x4
>> -#define MSR_CLK_REG1         0x8
>> -#define MSR_CLK_REG2         0xc
>> -
>>   #define MSR_DURATION                GENMASK(15, 0)
>>   #define MSR_ENABLE          BIT(16)
>>   #define MSR_CONT            BIT(17) /* continuous measurement */
>> @@ -39,9 +34,20 @@ struct meson_msr_id {
>>       const char *name;
>>   };
>>
>> +struct msr_reg_offset {
>> +     unsigned int duty;
>> +     unsigned int reg0;
>> +     unsigned int reg1;
>> +     unsigned int reg2;
>> +     unsigned int reg3;
>> +     unsigned int reg4;
>> +     unsigned int reg5;
>> +};
>
> I don't object, but:
> 1) could you help actually put a real name on those registers ?


The clk-measure registers and their corresponding functions in our
released documentation are as follows:
MSR_CLK_DUTY: Accumulates counts of clock high/low levels within a
measurement window for duty cycle calculation.
MSR_CLK_REG0: Control register for clock frequency measurement.
MSR_CLK_REG1: Control register for clock duty cycle measurement.
MSR_CLK_REG2: Accumulates total cycle counts within the measurement
window for frequency calculation.
MSR_CLK_REG3-6: Debug status registers for clk-measure (typically
unused in normal operation).

Register Renaming for Next Version:
"duty" -> "duty_val"
"reg0" -> "freq_ctrl"
"reg1" -> "duty_ctrl"
"reg2" -> "freq_val"


> 2) why adding regs 3, 4 & 5 if you don't use them ?


These three registers are unused in normal operation and will be removed
in the next version.


>
>> +
>>   struct meson_msr_data {
>>       struct meson_msr_id *msr_table;
>>       unsigned int msr_count;
>> +     struct msr_reg_offset reg;
>>   };
>>
>>   struct meson_msr {
>> @@ -495,6 +501,7 @@ static int meson_measure_id(struct meson_msr_id 
>> *clk_msr_id,
>>                           unsigned int duration)
>>   {
>>       struct meson_msr *priv = clk_msr_id->priv;
>> +     struct msr_reg_offset *reg = &priv->data.reg;
>>       unsigned int val;
>>       int ret;
>>
>> @@ -502,22 +509,22 @@ static int meson_measure_id(struct meson_msr_id 
>> *clk_msr_id,
>>       if (ret)
>>               return ret;
>>
>> -     regmap_write(priv->regmap, MSR_CLK_REG0, 0);
>> +     regmap_write(priv->regmap, reg->reg0, 0);
>>
>>       /* Set measurement duration */
>> -     regmap_update_bits(priv->regmap, MSR_CLK_REG0, MSR_DURATION,
>> +     regmap_update_bits(priv->regmap, reg->reg0, MSR_DURATION,
>>                          FIELD_PREP(MSR_DURATION, duration - 1));
>>
>>       /* Set ID */
>> -     regmap_update_bits(priv->regmap, MSR_CLK_REG0, MSR_CLK_SRC,
>> +     regmap_update_bits(priv->regmap, reg->reg0, MSR_CLK_SRC,
>>                          FIELD_PREP(MSR_CLK_SRC, clk_msr_id->id));
>>
>>       /* Enable & Start */
>> -     regmap_update_bits(priv->regmap, MSR_CLK_REG0,
>> +     regmap_update_bits(priv->regmap, reg->reg0,
>>                          MSR_RUN | MSR_ENABLE,
>>                          MSR_RUN | MSR_ENABLE);
>>
>> -     ret = regmap_read_poll_timeout(priv->regmap, MSR_CLK_REG0,
>> +     ret = regmap_read_poll_timeout(priv->regmap, reg->reg0,
>>                                      val, !(val & MSR_BUSY), 10, 10000);
>>       if (ret) {
>>               mutex_unlock(&measure_lock);
>> @@ -525,10 +532,10 @@ static int meson_measure_id(struct meson_msr_id 
>> *clk_msr_id,
>>       }
>>
>>       /* Disable */
>> -     regmap_update_bits(priv->regmap, MSR_CLK_REG0, MSR_ENABLE, 0);
>> +     regmap_update_bits(priv->regmap, reg->reg0, MSR_ENABLE, 0);
>>
>>       /* Get the value in multiple of gate time counts */
>> -     regmap_read(priv->regmap, MSR_CLK_REG2, &val);
>> +     regmap_read(priv->regmap, reg->reg2, &val);
>>
>>       mutex_unlock(&measure_lock);
>>
>> @@ -599,11 +606,10 @@ static int clk_msr_summary_show(struct seq_file 
>> *s, void *data)
>>   }
>>   DEFINE_SHOW_ATTRIBUTE(clk_msr_summary);
>>
>> -static const struct regmap_config meson_clk_msr_regmap_config = {
>> +static struct regmap_config meson_clk_msr_regmap_config = {
>>       .reg_bits = 32,
>>       .val_bits = 32,
>>       .reg_stride = 4,
>> -     .max_register = MSR_CLK_REG2,
>>   };
>>
>>   static int meson_msr_probe(struct platform_device *pdev)
>> @@ -611,6 +617,7 @@ static int meson_msr_probe(struct platform_device 
>> *pdev)
>>       const struct meson_msr_data *match_data;
>>       struct meson_msr *priv;
>>       struct dentry *root, *clks;
>> +     struct resource *res;
>>       void __iomem *base;
>>       int i;
>>
>> @@ -636,15 +643,18 @@ static int meson_msr_probe(struct 
>> platform_device *pdev)
>>              match_data->msr_count * sizeof(struct meson_msr_id));
>>       priv->data.msr_count = match_data->msr_count;
>>
>> -     base = devm_platform_ioremap_resource(pdev, 0);
>> +     base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
>>       if (IS_ERR(base))
>>               return PTR_ERR(base);
>>
>> +     meson_clk_msr_regmap_config.max_register = resource_size(res) - 4;
>>       priv->regmap = devm_regmap_init_mmio(&pdev->dev, base,
>> &meson_clk_msr_regmap_config);
>>       if (IS_ERR(priv->regmap))
>>               return PTR_ERR(priv->regmap);
>>
>> +     memcpy(&priv->data.reg, &match_data->reg, sizeof(struct 
>> msr_reg_offset));
>> +
>>       root = debugfs_create_dir("meson-clk-msr", NULL);
>>       clks = debugfs_create_dir("clks", root);
>>
>> @@ -667,26 +677,56 @@ static int meson_msr_probe(struct 
>> platform_device *pdev)
>>   static const struct meson_msr_data clk_msr_gx_data = {
>>       .msr_table = (void *)clk_msr_gx,
>>       .msr_count = ARRAY_SIZE(clk_msr_gx),
>> +     .reg = {
>> +             .duty = 0x0,
>> +             .reg0 = 0x4,
>> +             .reg1 = 0x8,
>> +             .reg2 = 0xc,
>> +     },
>
> Would be great to not duplicate this struct.


Okay, I'll change it to use the same struct across multiplechips.


>
>>   };
>>
>>   static const struct meson_msr_data clk_msr_m8_data = {
>>       .msr_table = (void *)clk_msr_m8,
>>       .msr_count = ARRAY_SIZE(clk_msr_m8),
>> +     .reg = {
>> +             .duty = 0x0,
>> +             .reg0 = 0x4,
>> +             .reg1 = 0x8,
>> +             .reg2 = 0xc,
>> +     },
>>   };
>>
>>   static const struct meson_msr_data clk_msr_axg_data = {
>>       .msr_table = (void *)clk_msr_axg,
>>       .msr_count = ARRAY_SIZE(clk_msr_axg),
>> +     .reg = {
>> +             .duty = 0x0,
>> +             .reg0 = 0x4,
>> +             .reg1 = 0x8,
>> +             .reg2 = 0xc,
>> +     },
>>   };
>>
>>   static const struct meson_msr_data clk_msr_g12a_data = {
>>       .msr_table = (void *)clk_msr_g12a,
>>       .msr_count = ARRAY_SIZE(clk_msr_g12a),
>> +     .reg = {
>> +             .duty = 0x0,
>> +             .reg0 = 0x4,
>> +             .reg1 = 0x8,
>> +             .reg2 = 0xc,
>> +     },
>>   };
>>
>>   static const struct meson_msr_data clk_msr_sm1_data = {
>>       .msr_table = (void *)clk_msr_sm1,
>>       .msr_count = ARRAY_SIZE(clk_msr_sm1),
>> +     .reg = {
>> +             .duty = 0x0,
>> +             .reg0 = 0x4,
>> +             .reg1 = 0x8,
>> +             .reg2 = 0xc,
>> +     },
>>   };
>>
>>   static const struct of_device_id meson_msr_match_table[] = {
>>
>
> Thanks,
> Neil