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Date:   Wed, 19 Jul 2023 12:09:20 +0800
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Subject: Re: [PATCH v2 2/2] Input: pm8xxx-vib - Add support for more PMICs
To:     Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
CC:     <linux-arm-msm@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        "Andy Gross" <agross@kernel.org>,
        Bjorn Andersson <andersson@kernel.org>,
        "Konrad Dybcio" <konrad.dybcio@linaro.org>,
        Dmitry Torokhov <dmitry.torokhov@gmail.com>,
        <linux-input@vger.kernel.org>, <quic_collinsd@quicinc.com>,
        <quic_subbaram@quicinc.com>, <quic_kamalw@quicinc.com>,
        <jestar@qti.qualcomm.com>, <quic_huliu@quicinc.com>
References: <20230718062639.2339589-1-quic_fenglinw@quicinc.com>
 <20230718062639.2339589-3-quic_fenglinw@quicinc.com>
 <CAA8EJpq_DGu3+kc_ex_2MUyiQFJvZhbWOc7NO6x1pO1Wx4RbNw@mail.gmail.com>
 <86631cb4-6b99-c3a7-428e-4534891da4c7@quicinc.com>
 <CAA8EJpr--XZnFJX96etagAa0uT0yNBcgZTfFDuu8gH2C5sgoCg@mail.gmail.com>
 <501bc7d0-1f97-1c53-a7f8-701ab9dfdf8e@quicinc.com>
 <CAA8EJppjshTCqeYQL1QUbLd03bopZjGHuOhoFqy7P8XuzYXc9w@mail.gmail.com>
Content-Language: en-US
From:   Fenglin Wu <quic_fenglinw@quicinc.com>
In-Reply-To: <CAA8EJppjshTCqeYQL1QUbLd03bopZjGHuOhoFqy7P8XuzYXc9w@mail.gmail.com>
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On 7/18/2023 7:04 PM, Dmitry Baryshkov wrote:
> On Tue, 18 Jul 2023 at 13:55, Fenglin Wu <quic_fenglinw@quicinc.com> wrote:
>>
>>
>>
>> On 7/18/2023 5:41 PM, Dmitry Baryshkov wrote:
>>> On Tue, 18 Jul 2023 at 09:58, Fenglin Wu <quic_fenglinw@quicinc.com> wrote:
>>>>
>>>>
>>>>
>>>> On 7/18/2023 2:44 PM, Dmitry Baryshkov wrote:
>>>>> On Tue, 18 Jul 2023 at 09:27, Fenglin Wu <quic_fenglinw@quicinc.com> wrote:
>>>>>>
>>>>>> Add support for vibrator module inside PMI632, PM7250B, PM7325B.
>>>>>> It is very similar to vibrator inside PM8xxx but just the drive
>>>>>> amplitude is controlled through 2 bytes registers.
>>>>>>
>>>>>> Signed-off-by: Fenglin Wu <quic_fenglinw@quicinc.com>
>>>>>> ---
>>>>>>     drivers/input/misc/pm8xxx-vibrator.c | 48 ++++++++++++++++++++++++++++
>>>>>>     1 file changed, 48 insertions(+)
>>>>>>
>>>>>> diff --git a/drivers/input/misc/pm8xxx-vibrator.c b/drivers/input/misc/pm8xxx-vibrator.c
>>>>>> index 04cb87efd799..213fdfd47c7f 100644
>>>>>> --- a/drivers/input/misc/pm8xxx-vibrator.c
>>>>>> +++ b/drivers/input/misc/pm8xxx-vibrator.c
>>>>>> @@ -25,6 +25,9 @@ struct pm8xxx_regs {
>>>>>>            unsigned int drv_addr;
>>>>>>            unsigned int drv_mask;
>>>>>>            unsigned int drv_shift;
>>>>>> +       unsigned int drv_addr2;
>>>>>> +       unsigned int drv_mask2;
>>>>>> +       unsigned int drv_shift2;
>>>>>>            unsigned int drv_en_manual_mask;
>>>>>>     };
>>>>>>
>>>>>> @@ -44,6 +47,42 @@ static struct pm8xxx_regs pm8916_regs = {
>>>>>>            .drv_en_manual_mask = 0,
>>>>>>     };
>>>>>>
>>>>>> +static struct pm8xxx_regs pmi632_regs = {
>>>>>> +       .enable_addr = 0x5746,
>>>>>> +       .enable_mask = BIT(7),
>>>>>> +       .drv_addr = 0x5740,
>>>>>> +       .drv_mask = 0xff,
>>>>>> +       .drv_shift = 0,
>>>>>> +       .drv_addr2 = 0x5741,
>>>>>> +       .drv_mask2 = 0x0f,
>>>>>> +       .drv_shift2 = 8,
>>>>>
>>>>> I see that you are just expanding what was done for SSBI PMICs and
>>>>> later expanded to support pm8916. However it might be better to drop
>>>>> the hardcoded .drv_addr (and drv_addr2) and read address from DT
>>>>> instead.
>>>>>
>>>>
>>>> Right, this is the simplest change without updating the code logic too
>>>> much. If we decided to read .drv_addr and .drv_add2 from DT, we will
>>>> have to read .enable_addr along with all other mask/shift for each
>>>> register address from DT as well because they are not consistent from
>>>> target to target. I don't know how would you suggest to add the DT
>>>> properties for all of them, but if we end up to add a property for each
>>>> of them, it won't be cleaner than hard-coding them.
>>>
>>> No, we (correctly) have device compatibles for that. The issue with
>>> hardcoding register addresses is that it adds extra issues here.
>>>
>>> If I understand correctly, we have several 'generation':
>>> - SSBI PMIC, shifted 5-bit mask, en_manual_mask, no enable_register.
>>> - older SPMI PMIC, 5 bit drv_mask, 0 en_manual_mask, enable register at +6
>>> - new SPMI PMIC, 12 bit drv_mask, 0 en_manual_mask, enable register at +6
>>>
>>> For the last generation you are adding three independent entries,
>>> while the block looks the same. If you remove drv_addr (and get it
>>> from reg property), it would allow us to keep only the functional data
>>> in struct pm8xxxx_regs (masks / shifts).
>>>
>>
>> Okay, let me know if I understood it correctly, this is what you are
>> suggesting:
>>
>>     - hard code the mask/shifts and still keep them in struct pm8xxx_regs,
>>       combine the drv_mask2 to the upper byte of the drv_mask, so we will
>>       have following data structure for the 3rd generation vibrator
>>
>>       static struct pm8xxx_regs pm7250b_regs = {
>>           .enable_addr = 0x5346,
>>           .enable_mask = BIT(7),
>>           .drv_mask = 0xfff,
>>           .drv_shift = 0,
>>           .drv_en_manual_mask = 0,
>>       };
>>
>>
>>     - move the drv_addr/drv_addr2 into DT, read them from 'reg' property.
>>       Because of 'mfd/qcom,spmi-pmic.yaml' has defined the 'address-cells'
>>       as 1 and the 'size-cells' as 0 for qcom spmi devices, we couldn't
>>       specify the address size to 2 even the drv_addr for the 3rd
>>       generation vibrator is 2 adjacent bytes. So we will end of having
>>       following DT scheme:
>>
>>         For the 2nd generation which only has drv_addr
>>          vibrator@c041 {
>>                compatible = "qcom,pm8916-vib";
>>                reg = <0xc041>;  /* drv_addr */
> 
> No. This is <0xc000>.
> 
>>                ...
>>          };
>>
>>         For the 3rd generation which has both drv_addr and drv_addr2
>>           vibrator@5340 {
>>                compatible = "qcom,pm7250b-vib";
>>               reg = <0x5340>,  /* drv_addr */
>>                     <0x5341>;  /* drv_addr2 */
>>               ...
>>          };
>>
>> Not sure how do you feel, I actually don't see too much benefit than
>> hard-coding them in the driver.
>> We will end up having code to check how many u32 value in the 'reg' and
>> only assign it to drv_addr2 when the 2nd is available, also when
>> programming drv_addr2 register, the driver will always assume the mask
>> is in the upper byte of the drv_mask and the shift to the drive level is
>> 8 (this seems hacky to me and it was my biggest concern while I made
>> this change, and it led me to defining drv_shift2/drv_mask2 along with
>> drv_addr2).
> 
> We only need drv_addr2 if drv_mask has more than 8 bits. So you don't
> have to specify it in the DT. It is always equal to base_reg + 0x41.
> The same way drv_addr is always equal to base_reg + 0x40 for all
> SPMI-based PMIC vibrator devices.
> 

Thanks. I got it now, I agree this will be beneficial for the case that 
different PMICs have the same vibrator module but with different 
register base address. I am going to change it to this way, let me know 
if this is what you thought:

@@ -25,6 +29,9 @@ struct pm8xxx_regs {
         unsigned int drv_addr;
         unsigned int drv_mask;
         unsigned int drv_shift;
+       unsigned int drv_addr2;
+       unsigned int drv_mask2;
+       unsigned int drv_shift2;
         unsigned int drv_en_manual_mask;
  };

+static struct pm8xxx_regs spmi_vib_regs = {
+       .enable_mask = BIT(7),
+       .drv_mask = 0xff,
+       .drv_shift = 0,
+       .drv_mask2 = 0xf,
+       .drv_shift2 = 8,
+       .drv_en_manual_mask = 0,
+};
+

+#define SPMI_VIB_VSET_LB_REG   0x40
+#define SPMI_VIB_VSET_UP_REG   0x41
+#define SPMI_VIB_EN_CTL_REG    0x46
+

         regs = of_device_get_match_data(&pdev->dev);

+       if (regs->drv_addr == 0) {
+               rc = fwnode_property_read_u32(pdev->dev.fwnode,
+                               "reg", &reg_base);
+               if (rc < 0)
+                       return rc;
+
+               regs->enable_addr = reg_base + SPMI_VIB_EN_CTL_REG;
+               regs->drv_addr = reg_base + SPMI_VIB_VSET_LB_REG;
+               regs->drv_addr2 = reg_base + SPMI_VIB_VSET_UP_REG;
+       }
+


@@ -242,6 +277,7 @@ static const struct of_device_id 
pm8xxx_vib_id_table[] = {
         { .compatible = "qcom,pm8058-vib", .data = &pm8058_regs },
         { .compatible = "qcom,pm8921-vib", .data = &pm8058_regs },
         { .compatible = "qcom,pm8916-vib", .data = &pm8916_regs },
+       ( .compabitle = "qcom,spmi-vib", .data = &spmi_vib_regs },
         { }


>>
>>
>>
>>>>
>>>>
>>>>>> +       .drv_en_manual_mask = 0,
>>>>>> +};
>>>>>> +
>>>>>> +static struct pm8xxx_regs pm7250b_regs = {
>>>>>> +       .enable_addr = 0x5346,
>>>>>> +       .enable_mask = BIT(7),
>>>>>> +       .drv_addr = 0x5340,
>>>>>> +       .drv_mask = 0xff,
>>>>>> +       .drv_shift = 0,
>>>>>> +       .drv_addr2 = 0x5341,
>>>>>> +       .drv_mask2 = 0x0f,
>>>>>> +       .drv_shift2 = 8,
>>>>>> +       .drv_en_manual_mask = 0,
>>>>>> +};
>>>>>> +
>>>>>> +static struct pm8xxx_regs pm7325b_regs = {
>>>>>> +       .enable_addr = 0xdf46,
>>>>>> +       .enable_mask = BIT(7),
>>>>>> +       .drv_addr = 0xdf40,
>>>>>> +       .drv_mask = 0xff,
>>>>>> +       .drv_shift = 0,
>>>>>> +       .drv_addr2 = 0xdf41,
>>>>>> +       .drv_mask2 = 0x0f,
>>>>>> +       .drv_shift2 = 8,
>>>>>> +       .drv_en_manual_mask = 0,
>>>>>> +};
>>>>>> +
>>>>>>     /**
>>>>>>      * struct pm8xxx_vib - structure to hold vibrator data
>>>>>>      * @vib_input_dev: input device supporting force feedback
>>>>>> @@ -87,6 +126,12 @@ static int pm8xxx_vib_set(struct pm8xxx_vib *vib, bool on)
>>>>>>                    return rc;
>>>>>>
>>>>>>            vib->reg_vib_drv = val;
>>>>>> +       if (regs->drv_addr2 != 0 && on) {
>>>>>> +               val = (vib->level << regs->drv_shift2) & regs->drv_mask2;
>>>>>> +               rc = regmap_write(vib->regmap, regs->drv_addr2, val);
>>>>>> +               if (rc < 0)
>>>>>> +                       return rc;
>>>>>> +       }
>>>>>>
>>>>>>            if (regs->enable_mask)
>>>>>>                    rc = regmap_update_bits(vib->regmap, regs->enable_addr,
>>>>>> @@ -242,6 +287,9 @@ static const struct of_device_id pm8xxx_vib_id_table[] = {
>>>>>>            { .compatible = "qcom,pm8058-vib", .data = &pm8058_regs },
>>>>>>            { .compatible = "qcom,pm8921-vib", .data = &pm8058_regs },
>>>>>>            { .compatible = "qcom,pm8916-vib", .data = &pm8916_regs },
>>>>>> +       { .compatible = "qcom,pmi632-vib", .data = &pmi632_regs },
>>>>>> +       { .compatible = "qcom,pm7250b-vib", .data = &pm7250b_regs },
>>>>>> +       { .compatible = "qcom,pm7325b-vib", .data = &pm7325b_regs },
>>>>>>            { }
>>>>>>     };
>>>>>>     MODULE_DEVICE_TABLE(of, pm8xxx_vib_id_table);
>>>>>> --
>>>>>> 2.25.1
>>>>>>
>>>>>
>>>>>
>>>
>>>
>>>
> 
> 
>