[PATCH 1/3] phy: stm32-usbphyc: add counter of PLL consumer

[Patrick DELAUNAY]

Hi Sean,

On 5/8/22 20:21, Sean Anderson wrote:
> On 4/26/22 8:37 AM, Patrick Delaunay wrote:
>> Add the counter of the PLL user n_pll_cons managed by the 2 functions
>> stm32_usbphyc_pll_enable / stm32_usbphyc_pll_disable.
>>
>> This counter allow to remove the function stm32_usbphyc_is_init
>> and it is a preliminary step for ck_usbo_48m introduction.
>
> Is it necessary to disable this clock before booting to Linux? If it 
> isn't,
> then perhaps it is simpler to just not disable the clock.
>
> --Sean


No, it is not necessary, we only need to enable the clock for the first 
user.

I copy the clock behavior from kernel,

but I agree that can be simpler.


Amelie any notice about this point ?

Do you prefer that I kept the behavior - same as kernel driver - or I 
simplify the U-Boot driver ?


Patrick


>
>> Signed-off-by: Patrick Delaunay <patrick.delaunay at foss.st.com>
>> ---
>>
>>   drivers/phy/phy-stm32-usbphyc.c | 76 +++++++++++++++++++++------------
>>   1 file changed, 48 insertions(+), 28 deletions(-)
>>
>> diff --git a/drivers/phy/phy-stm32-usbphyc.c 
>> b/drivers/phy/phy-stm32-usbphyc.c
>> index 9c1dcfae52..16c8799eca 100644
>> --- a/drivers/phy/phy-stm32-usbphyc.c
>> +++ b/drivers/phy/phy-stm32-usbphyc.c
>> @@ -65,6 +65,7 @@ struct stm32_usbphyc {
>>           bool init;
>>           bool powered;
>>       } phys[MAX_PHYS];
>> +    int n_pll_cons;
>>   };
>>     static void stm32_usbphyc_get_pll_params(u32 clk_rate,
>> @@ -124,18 +125,6 @@ static int stm32_usbphyc_pll_init(struct 
>> stm32_usbphyc *usbphyc)
>>       return 0;
>>   }
>>   -static bool stm32_usbphyc_is_init(struct stm32_usbphyc *usbphyc)
>> -{
>> -    int i;
>> -
>> -    for (i = 0; i < MAX_PHYS; i++) {
>> -        if (usbphyc->phys[i].init)
>> -            return true;
>> -    }
>> -
>> -    return false;
>> -}
>> -
>>   static bool stm32_usbphyc_is_powered(struct stm32_usbphyc *usbphyc)
>>   {
>>       int i;
>> @@ -148,18 +137,17 @@ static bool stm32_usbphyc_is_powered(struct 
>> stm32_usbphyc *usbphyc)
>>       return false;
>>   }
>>   -static int stm32_usbphyc_phy_init(struct phy *phy)
>> +static int stm32_usbphyc_pll_enable(struct stm32_usbphyc *usbphyc)
>>   {
>> -    struct stm32_usbphyc *usbphyc = dev_get_priv(phy->dev);
>> -    struct stm32_usbphyc_phy *usbphyc_phy = usbphyc->phys + phy->id;
>>       bool pllen = readl(usbphyc->base + STM32_USBPHYC_PLL) & PLLEN ?
>>                true : false;
>>       int ret;
>>   -    dev_dbg(phy->dev, "phy ID = %lu\n", phy->id);
>> -    /* Check if one phy port has already configured the pll */
>> -    if (pllen && stm32_usbphyc_is_init(usbphyc))
>> -        goto initialized;
>> +    /* Check if one consumer has already configured the pll */
>> +    if (pllen && usbphyc->n_pll_cons) {
>> +        usbphyc->n_pll_cons++;
>> +        return 0;
>> +    }
>>         if (usbphyc->vdda1v1) {
>>           ret = regulator_set_enable(usbphyc->vdda1v1, true);
>> @@ -190,23 +178,19 @@ static int stm32_usbphyc_phy_init(struct phy *phy)
>>       if (!(readl(usbphyc->base + STM32_USBPHYC_PLL) & PLLEN))
>>           return -EIO;
>>   -initialized:
>> -    usbphyc_phy->init = true;
>> +    usbphyc->n_pll_cons++;
>>         return 0;
>>   }
>>   -static int stm32_usbphyc_phy_exit(struct phy *phy)
>> +static int stm32_usbphyc_pll_disable(struct stm32_usbphyc *usbphyc)
>>   {
>> -    struct stm32_usbphyc *usbphyc = dev_get_priv(phy->dev);
>> -    struct stm32_usbphyc_phy *usbphyc_phy = usbphyc->phys + phy->id;
>>       int ret;
>>   -    dev_dbg(phy->dev, "phy ID = %lu\n", phy->id);
>> -    usbphyc_phy->init = false;
>> +    usbphyc->n_pll_cons--;
>>   -    /* Check if other phy port requires pllen */
>> -    if (stm32_usbphyc_is_init(usbphyc))
>> +    /* Check if other consumer requires pllen */
>> +    if (usbphyc->n_pll_cons)
>>           return 0;
>>         clrbits_le32(usbphyc->base + STM32_USBPHYC_PLL, PLLEN);
>> @@ -235,6 +219,42 @@ static int stm32_usbphyc_phy_exit(struct phy *phy)
>>       return 0;
>>   }
>>   +static int stm32_usbphyc_phy_init(struct phy *phy)
>> +{
>> +    struct stm32_usbphyc *usbphyc = dev_get_priv(phy->dev);
>> +    struct stm32_usbphyc_phy *usbphyc_phy = usbphyc->phys + phy->id;
>> +    int ret;
>> +
>> +    dev_dbg(phy->dev, "phy ID = %lu\n", phy->id);
>> +    if (usbphyc_phy->init)
>> +        return 0;
>> +
>> +    ret = stm32_usbphyc_pll_enable(usbphyc);
>> +    if (ret)
>> +        return log_ret(ret);
>> +
>> +    usbphyc_phy->init = true;
>> +
>> +    return 0;
>> +}
>> +
>> +static int stm32_usbphyc_phy_exit(struct phy *phy)
>> +{
>> +    struct stm32_usbphyc *usbphyc = dev_get_priv(phy->dev);
>> +    struct stm32_usbphyc_phy *usbphyc_phy = usbphyc->phys + phy->id;
>> +    int ret;
>> +
>> +    dev_dbg(phy->dev, "phy ID = %lu\n", phy->id);
>> +    if (!usbphyc_phy->init)
>> +        return 0;
>> +
>> +    ret = stm32_usbphyc_pll_disable(usbphyc);
>> +
>> +    usbphyc_phy->init = false;
>> +
>> +    return log_ret(ret);
>> +}
>> +
>>   static int stm32_usbphyc_phy_power_on(struct phy *phy)
>>   {
>>       struct stm32_usbphyc *usbphyc = dev_get_priv(phy->dev);
>>
>