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

[Sean Anderson]

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

> 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);
>