Re: [PATCH 4/5] thermal: khadas_mcu_fan: add support for Khadas Edge 2

[Muhammed Efe Cetin <muhammed.efecetin.67@gmail.com>]

On 6/26/25 17:46, neil.armstrong@linaro.org wrote:
> On 26/06/2025 16:36, muhammed.efecetin.67@gmail.com wrote:
>> On 6/26/25 17:11, neil.armstrong@linaro.org wrote:
>>> On 26/06/2025 16:04, muhammed.efecetin.67@gmail.com wrote:
>>>> From: Muhammed Efe Cetin <efectn@protonmail.com>
>>>>
>>>> Fan control on the Khadas Edge 2 is controlled with the 0x8A register,
>>>> using percentage values from 0 to 100, whereas there are only 3 constant steps in previous Khadas boards.
>>>> Therefore, i added a new cooling-levels property, similar to the one used in the pwm-fan driver.
>>>> The original behavior can still be used when the cooling-levels property is not specified,
>>>> ensuring that the new functionality does not break old boards. 
>>>
>>> Thanks for the explanation, but would would you like to change that ? The MCU can accept
>>> any value between 0 and 99, so why change the levels from DT ?
>>>
>>> Neil 
>>
>> Thanks for the review. Therefore, you say just add values between 0-100 to cooling-device instead of remapping them using cooling-levels property?
>>
>> What would be the best practise of detecting whether the board is Khadas Edge 2? Adding new bool property, reading model propety from devicetree etc. 
>
> The register DEVICE_NO should be set at 0x12 for Edge V, 0x11 for Edge 1. I don't have the number for Edge 2, perhaps you can read it ?
>
> Neil

The DEVICE_NO register is not available for Khadas Edge 2. Here are the registers [0].

[0] https://dl.khadas.com/products/edge2/tools/mcu/edge2-mcu-register-description-en-v1.0-230520.pdf

>
>>
>> Best regards.
>>
>>>
>>>>
>>>> Signed-off-by: Muhammed Efe Cetin <efectn@protonmail.com>
>>>> ---
>>>>    drivers/thermal/khadas_mcu_fan.c | 76 ++++++++++++++++++++++++++++++--
>>>>    1 file changed, 72 insertions(+), 4 deletions(-)
>>>>
>>>> diff --git a/drivers/thermal/khadas_mcu_fan.c b/drivers/thermal/khadas_mcu_fan.c
>>>> index d35e5313b..504e7d254 100644
>>>> --- a/drivers/thermal/khadas_mcu_fan.c
>>>> +++ b/drivers/thermal/khadas_mcu_fan.c
>>>> @@ -15,10 +15,16 @@
>>>>    #include <linux/thermal.h>
>>>>      #define MAX_LEVEL 3
>>>> +#define MAX_SPEED 0x64
>>>>      struct khadas_mcu_fan_ctx {
>>>>        struct khadas_mcu *mcu;
>>>>        unsigned int level;
>>>> +
>>>> +    unsigned int fan_max_level;
>>>> +    unsigned int fan_register;
>>>> +    unsigned int *fan_cooling_levels;
>>>> +
>>>>        struct thermal_cooling_device *cdev;
>>>>    };
>>>>    @@ -26,9 +32,21 @@ static int khadas_mcu_fan_set_level(struct khadas_mcu_fan_ctx *ctx,
>>>>                        unsigned int level)
>>>>    {
>>>>        int ret;
>>>> +    unsigned int write_level = level;
>>>> +
>>>> +    if (level > ctx->fan_max_level)
>>>> +        return -EINVAL;
>>>> +
>>>> +    if (ctx->fan_cooling_levels != NULL) {
>>>> +        write_level = ctx->fan_cooling_levels[level];
>>>> +
>>>> +        if (write_level > MAX_SPEED)
>>>> +            return -EINVAL;
>>>> +    }
>>>> +
>>>> +    ret = regmap_write(ctx->mcu->regmap, ctx->fan_register,
>>>> +               write_level);
>>>>    -    ret = regmap_write(ctx->mcu->regmap, KHADAS_MCU_CMD_FAN_STATUS_CTRL_REG,
>>>> -               level);
>>>>        if (ret)
>>>>            return ret;
>>>>    @@ -40,7 +58,9 @@ static int khadas_mcu_fan_set_level(struct khadas_mcu_fan_ctx *ctx,
>>>>    static int khadas_mcu_fan_get_max_state(struct thermal_cooling_device *cdev,
>>>>                        unsigned long *state)
>>>>    {
>>>> -    *state = MAX_LEVEL;
>>>> +    struct khadas_mcu_fan_ctx *ctx = cdev->devdata;
>>>> +
>>>> +    *state = ctx->fan_max_level;
>>>>          return 0;
>>>>    }
>>>> @@ -61,7 +81,7 @@ khadas_mcu_fan_set_cur_state(struct thermal_cooling_device *cdev,
>>>>    {
>>>>        struct khadas_mcu_fan_ctx *ctx = cdev->devdata;
>>>>    -    if (state > MAX_LEVEL)
>>>> +    if (state > ctx->fan_max_level)
>>>>            return -EINVAL;
>>>>          if (state == ctx->level)
>>>> @@ -76,6 +96,47 @@ static const struct thermal_cooling_device_ops khadas_mcu_fan_cooling_ops = {
>>>>        .set_cur_state = khadas_mcu_fan_set_cur_state,
>>>>    };
>>>>    +static int khadas_mcu_fan_get_cooling_data_edge2(struct khadas_mcu_fan_ctx *ctx, struct device *dev)
>>>> +{
>>>> +    struct device_node *np = ctx->mcu->dev->of_node;
>>>> +    int num, i, ret;
>>>> +
>>>> +    if (!of_property_present(np, "cooling-levels"))
>>>> +        return 0;
>>>> +
>>>> +    ret = of_property_count_u32_elems(np, "cooling-levels");
>>>> +    if (ret <= 0) {
>>>> +        dev_err(dev, "Wrong data!\n");
>>>> +        return ret ? : -EINVAL;
>>>> +    }
>>>> +
>>>> +    num = ret;
>>>> +    ctx->fan_cooling_levels = devm_kcalloc(dev, num, sizeof(u32),
>>>> +                           GFP_KERNEL);
>>>> +    if (!ctx->fan_cooling_levels)
>>>> +        return -ENOMEM;
>>>> +
>>>> +    ret = of_property_read_u32_array(np, "cooling-levels",
>>>> +                     ctx->fan_cooling_levels, num);
>>>> +    if (ret) {
>>>> +        dev_err(dev, "Property 'cooling-levels' cannot be read!\n");
>>>> +        return ret;
>>>> +    }
>>>> +
>>>> +    for (i = 0; i < num; i++) {
>>>> +        if (ctx->fan_cooling_levels[i] > MAX_SPEED) {
>>>> +            dev_err(dev, "MCU fan state[%d]:%d > %d\n", i,
>>>> +                ctx->fan_cooling_levels[i], MAX_SPEED);
>>>> +            return -EINVAL;
>>>> +        }
>>>> +    }
>>>> +
>>>> +    ctx->fan_max_level = num - 1;
>>>> +    ctx->fan_register = KHADAS_MCU_CMD_FAN_STATUS_CTRL_REG_V2;
>>>> +
>>>> +    return 0;
>>>> +}
>>>> +
>>>>    static int khadas_mcu_fan_probe(struct platform_device *pdev)
>>>>    {
>>>>        struct khadas_mcu *mcu = dev_get_drvdata(pdev->dev.parent);
>>>> @@ -90,6 +151,13 @@ static int khadas_mcu_fan_probe(struct platform_device *pdev)
>>>>        ctx->mcu = mcu;
>>>>        platform_set_drvdata(pdev, ctx);
>>>>    +    ctx->fan_max_level = MAX_LEVEL;
>>>> +    ctx->fan_register = KHADAS_MCU_CMD_FAN_STATUS_CTRL_REG;
>>>> +
>>>> +    ret = khadas_mcu_fan_get_cooling_data_edge2(ctx, dev);
>>>> +    if (ret)
>>>> +        return ret;
>>>> +
>>>>        cdev = devm_thermal_of_cooling_device_register(dev->parent,
>>>>                dev->parent->of_node, "khadas-mcu-fan", ctx,
>>>>                &khadas_mcu_fan_cooling_ops); 
>>>
>>
>