Re: [PATCH v7 18/26] PM / devfreq: rockchip-dfi: account for multiple DDRMON_CTRL registers

[Chanwoo Choi <chanwoo@kernel.org>]

On 23. 10. 16. 21:49, Sascha Hauer wrote:
> On Mon, Oct 09, 2023 at 07:19:04AM +0900, Chanwoo Choi wrote:
>> On 23. 7. 4. 18:32, Sascha Hauer wrote:
>>> The currently supported RK3399 has a set of registers per channel, but
>>> it has only a single DDRMON_CTRL register. With upcoming RK3588 this
>>> will be different, the RK3588 has a DDRMON_CTRL register per channel.
>>>
>>> Instead of expecting a single DDRMON_CTRL register, loop over the
>>> channels and write the channel specific DDRMON_CTRL register. Break
>>> out early out of the loop when there is only a single DDRMON_CTRL
>>> register like on the RK3399.
>>>
>>> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
>>> Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.com>
>>> Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
>>> ---
>>>  drivers/devfreq/event/rockchip-dfi.c | 72 ++++++++++++++++++----------
>>>  1 file changed, 48 insertions(+), 24 deletions(-)
>>>
>>> diff --git a/drivers/devfreq/event/rockchip-dfi.c b/drivers/devfreq/event/rockchip-dfi.c
>>> index 85ec93fd41858..2362d3953ba40 100644
>>> --- a/drivers/devfreq/event/rockchip-dfi.c
>>> +++ b/drivers/devfreq/event/rockchip-dfi.c
>>> @@ -113,12 +113,13 @@ struct rockchip_dfi {
>>>  	int burst_len;
>>>  	int buswidth[DMC_MAX_CHANNELS];
>>>  	int ddrmon_stride;
>>> +	bool ddrmon_ctrl_single;
>>>  };
>>>  
>>>  static int rockchip_dfi_enable(struct rockchip_dfi *dfi)
>>>  {
>>>  	void __iomem *dfi_regs = dfi->regs;
>>> -	int ret = 0;
>>> +	int i, ret = 0;
>>>  
>>>  	mutex_lock(&dfi->mutex);
>>>  
>>> @@ -132,29 +133,41 @@ static int rockchip_dfi_enable(struct rockchip_dfi *dfi)
>>>  		goto out;
>>>  	}
>>>  
>>> -	/* clear DDRMON_CTRL setting */
>>> -	writel_relaxed(HIWORD_UPDATE(0, DDRMON_CTRL_TIMER_CNT_EN | DDRMON_CTRL_SOFTWARE_EN |
>>> -		       DDRMON_CTRL_HARDWARE_EN), dfi_regs + DDRMON_CTRL);
>>> +	for (i = 0; i < DMC_MAX_CHANNELS; i++) {
>>> +		u32 ctrl = 0;
>>>  
>>> -	/* set ddr type to dfi */
>>> -	switch (dfi->ddr_type) {
>>> -	case ROCKCHIP_DDRTYPE_LPDDR2:
>>> -	case ROCKCHIP_DDRTYPE_LPDDR3:
>>> -		writel_relaxed(HIWORD_UPDATE(DDRMON_CTRL_LPDDR23, DDRMON_CTRL_DDR_TYPE_MASK),
>>> -			       dfi_regs + DDRMON_CTRL);
>>> -		break;
>>> -	case ROCKCHIP_DDRTYPE_LPDDR4:
>>> -	case ROCKCHIP_DDRTYPE_LPDDR4X:
>>> -		writel_relaxed(HIWORD_UPDATE(DDRMON_CTRL_LPDDR4, DDRMON_CTRL_DDR_TYPE_MASK),
>>> -			       dfi_regs + DDRMON_CTRL);
>>> -		break;
>>> -	default:
>>> -		break;
>>> -	}
>>> +		if (!(dfi->channel_mask & BIT(i)))
>>> +			continue;
>>>  
>>> -	/* enable count, use software mode */
>>> -	writel_relaxed(HIWORD_UPDATE(DDRMON_CTRL_SOFTWARE_EN, DDRMON_CTRL_SOFTWARE_EN),
>>> -		       dfi_regs + DDRMON_CTRL);
>>> +		/* clear DDRMON_CTRL setting */
>>> +		writel_relaxed(HIWORD_UPDATE(0, DDRMON_CTRL_TIMER_CNT_EN |
>>> +			       DDRMON_CTRL_SOFTWARE_EN | DDRMON_CTRL_HARDWARE_EN),
>>> +			       dfi_regs + i * dfi->ddrmon_stride + DDRMON_CTRL);
>>> +
>>> +		/* set ddr type to dfi */
>>> +		switch (dfi->ddr_type) {
>>> +		case ROCKCHIP_DDRTYPE_LPDDR2:
>>> +		case ROCKCHIP_DDRTYPE_LPDDR3:
>>> +			ctrl = DDRMON_CTRL_LPDDR23;
>>> +			break;
>>> +		case ROCKCHIP_DDRTYPE_LPDDR4:
>>> +		case ROCKCHIP_DDRTYPE_LPDDR4X:
>>> +			ctrl = DDRMON_CTRL_LPDDR4;
>>> +			break;
>>> +		default:
>>> +			break;
>>> +		}
>>> +
>>> +		writel_relaxed(HIWORD_UPDATE(ctrl, DDRMON_CTRL_DDR_TYPE_MASK),
>>> +			       dfi_regs + i * dfi->ddrmon_stride + DDRMON_CTRL);
>>> +
>>> +		/* enable count, use software mode */
>>> +		writel_relaxed(HIWORD_UPDATE(DDRMON_CTRL_SOFTWARE_EN, DDRMON_CTRL_SOFTWARE_EN),
>>> +			       dfi_regs + i * dfi->ddrmon_stride + DDRMON_CTRL);
>>> +
>>> +		if (dfi->ddrmon_ctrl_single)
>>> +			break;
>>> +	}
>>>  out:
>>>  	mutex_unlock(&dfi->mutex);
>>>  
>>> @@ -164,6 +177,7 @@ static int rockchip_dfi_enable(struct rockchip_dfi *dfi)
>>>  static void rockchip_dfi_disable(struct rockchip_dfi *dfi)
>>>  {
>>>  	void __iomem *dfi_regs = dfi->regs;
>>> +	int i;
>>>  
>>>  	mutex_lock(&dfi->mutex);
>>>  
>>> @@ -174,8 +188,17 @@ static void rockchip_dfi_disable(struct rockchip_dfi *dfi)
>>>  	if (dfi->usecount > 0)
>>>  		goto out;
>>>  
>>> -	writel_relaxed(HIWORD_UPDATE(0, DDRMON_CTRL_SOFTWARE_EN),
>>> -		       dfi_regs + DDRMON_CTRL);
>>> +	for (i = 0; i < DMC_MAX_CHANNELS; i++) {
>>> +		if (!(dfi->channel_mask & BIT(i)))
>>> +			continue;
>>> +
>>> +		writel_relaxed(HIWORD_UPDATE(0, DDRMON_CTRL_SOFTWARE_EN),
>>> +			      dfi_regs + i * dfi->ddrmon_stride + DDRMON_CTRL);
>>> +
>>> +		if (dfi->ddrmon_ctrl_single)
>>> +			break;
>>> +	}
>>> +
>>>  	clk_disable_unprepare(dfi->clk);
>>>  out:
>>>  	mutex_unlock(&dfi->mutex);
>>> @@ -666,6 +689,7 @@ static int rk3399_dfi_init(struct rockchip_dfi *dfi)
>>>  	dfi->buswidth[1] = FIELD_GET(RK3399_PMUGRF_OS_REG2_BW_CH1, val) == 0 ? 4 : 2;
>>>  
>>>  	dfi->ddrmon_stride = 0x14;
>>> +	dfi->ddrmon_ctrl_single = true;
>>>  
>>>  	return 0;
>>>  };
>>
>> Even if rk3568 has the only one channle and don't need to check whether 'dfi->ddrmon_ctrl_single'
>> is true or not because of 'if (!(dfi->channel_mask & BIT(i)))',
>> I recommand the add 'dfi->ddrmon_ctrl_single = true;' for rk3568 in order to
>> provide the number of DDRMON_CTRL reigster of rk3568.
>>
>> If rk3568 doesn't have the 'ddrmon_ctrl_single', actually it is not easy
>> to catch what why are there no initilization for rk3568.
> 
> Ok, will change.
> 

Thanks.

-- 
Best Regards,
Samsung Electronics
Chanwoo Choi