linux-kernel - Re: [PATCH v9 2/4] input: pm8xxx-vibrator: refactor to support new SPMI vibrator

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Date: Fri, 12 Apr 2024 11:40:53 +0800
From: Fenglin Wu <quic_fenglinw@...cinc.com>
To: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
CC: <kernel@...cinc.com>, Andy Gross <agross@...nel.org>,
        Bjorn Andersson
	<andersson@...nel.org>,
        Konrad Dybcio <konrad.dybcio@...aro.org>,
        "Dmitry
 Torokhov" <dmitry.torokhov@...il.com>,
        Rob Herring <robh+dt@...nel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
        <linux-arm-msm@...r.kernel.org>, <linux-input@...r.kernel.org>,
        <linux-kernel@...r.kernel.org>, <devicetree@...r.kernel.org>
Subject: Re: [PATCH v9 2/4] input: pm8xxx-vibrator: refactor to support new
 SPMI vibrator



On 4/11/2024 10:05 PM, Dmitry Baryshkov wrote:
> On Thu, 11 Apr 2024 at 16:45, Fenglin Wu <quic_fenglinw@...cinc.com> wrote:
>>
>>
>>
>> On 2024/4/11 18:58, Dmitry Baryshkov wrote:
>>> On Thu, 11 Apr 2024 at 11:32, Fenglin Wu via B4 Relay
>>> <devnull+quic_fenglinw.quicinc.com@...nel.org> wrote:
>>>>
>>>> From: Fenglin Wu <quic_fenglinw@...cinc.com>
>>>>
>>>> Currently, vibrator control register addresses are hard coded,
>>>> including the base address and offsets, it's not flexible to
>>>> support new SPMI vibrator module which is usually included in
>>>> different PMICs with different base address. Refactor it by using
>>>> the base address defined in devicetree.
>>>>
>>>> Signed-off-by: Fenglin Wu <quic_fenglinw@...cinc.com>
>>>> ---
>>>>    drivers/input/misc/pm8xxx-vibrator.c | 42 ++++++++++++++++++++++++------------
>>>>    1 file changed, 28 insertions(+), 14 deletions(-)
>>>>
>>>> diff --git a/drivers/input/misc/pm8xxx-vibrator.c b/drivers/input/misc/pm8xxx-vibrator.c
>>>> index 89f0f1c810d8..2959edca8eb9 100644
>>>> --- a/drivers/input/misc/pm8xxx-vibrator.c
>>>> +++ b/drivers/input/misc/pm8xxx-vibrator.c
>>>> @@ -20,26 +20,26 @@
>>>>    #define MAX_FF_SPEED           0xff
>>>>
>>>>    struct pm8xxx_regs {
>>>> -       unsigned int enable_addr;
>>>> +       unsigned int enable_offset;
>>>>           unsigned int enable_mask;
>>>>
>>>> -       unsigned int drv_addr;
>>>> +       unsigned int drv_offset;
>>>>           unsigned int drv_mask;
>>>>           unsigned int drv_shift;
>>>>           unsigned int drv_en_manual_mask;
>>>>    };
>>>>
>>>>    static const struct pm8xxx_regs pm8058_regs = {
>>>> -       .drv_addr = 0x4A,
>>>> +       .drv_offset = 0x4A,
>>>
>>> If the DT already has reg = <0x4a> and you add drv_offset = 0x4a,
>>> which register will be used by the driver?
>>>
>>> Also, while we are at it, please downcase all the hex numbers that you
>>> are touching.
>>>
>> For SSBI vibrator, the "reg" value defined in DT is not used, see below.
>>
>>
>>>>           .drv_mask = 0xf8,
>>>>           .drv_shift = 3,
>>>>           .drv_en_manual_mask = 0xfc,
>>>>    };
>>>>
>>>>    static struct pm8xxx_regs pm8916_regs = {
>>>> -       .enable_addr = 0xc046,
>>>> +       .enable_offset = 0x46,
>>
>> [...]
>>
>>>> @@ -170,7 +173,7 @@ static int pm8xxx_vib_probe(struct platform_device *pdev)
>>>>           struct pm8xxx_vib *vib;
>>>>           struct input_dev *input_dev;
>>>>           int error;
>>>> -       unsigned int val;
>>>> +       unsigned int val, reg_base = 0;
>>>>           const struct pm8xxx_regs *regs;
>>>>
>>>>           vib = devm_kzalloc(&pdev->dev, sizeof(*vib), GFP_KERNEL);
>>>> @@ -190,13 +193,24 @@ static int pm8xxx_vib_probe(struct platform_device *pdev)
>>>>
>>>>           regs = of_device_get_match_data(&pdev->dev);
>>>>
>>>> +       if (regs->enable_offset != 0) {
>>>> +               error = fwnode_property_read_u32(pdev->dev.fwnode, "reg", &reg_base);
>>>> +               if (error < 0) {
>>>> +                       dev_err(&pdev->dev, "Failed to read reg address, rc=%d\n", error);
>>>> +                       return error;
>>>> +               }
>>>> +       }
>>>> +
>>>> +       vib->enable_addr = reg_base + regs->enable_offset;
>>>> +       vib->drv_addr = reg_base + regs->drv_offset;
>>
>> The reg_base is initialized as 0 and it is assigned as the "reg" value
>> defined in DT only for SPMI vibrators.
> 
> Please don't. This is counterintuitive. We have reg in DT. We should
> be using it.
> 
Hmm, the original driver doesn't use the reg value defined in DT at all, 
Anyway, I can make the SSBI offset to 0, so the base address defined in 
the DT will be always added regardless of SSBI or SPMI vibrator. Let me 
know.
Thanks

>>
>>>> +
>>>>           /* operate in manual mode */
>>>> -       error = regmap_read(vib->regmap, regs->drv_addr, &val);
>>>> +       error = regmap_read(vib->regmap, vib->drv_addr, &val);
>>>>           if (error < 0)
>>>>                   return error;
>>>>
>>>>           val &= regs->drv_en_manual_mask;
>>>> -       error = regmap_write(vib->regmap, regs->drv_addr, val);
>>>> +       error = regmap_write(vib->regmap, vib->drv_addr, val);
>>>>           if (error < 0)
>>>>                   return error;
>>>>
>>>>
>>>> --
>>>> 2.25.1
>>>>
>>>>
>>>
>>>
> 
> 
>