Re: [PATCH 3/4] PCI: mediatek-gen3: rely on reset_bulk APIs for phy reset lines

[Lorenzo Bianconi <lorenzo@kernel.org>]

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> Il 21/06/24 16:48, Lorenzo Bianconi ha scritto:
> > Use reset_bulk APIs to manage phy reset lines. This is a preliminary
> > patch in order to add Airoha EN7581 pcie support.
> > 
> > Tested-by: Zhengping Zhang <zhengping.zhang@airoha.com>
> > Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
> > ---
> >   drivers/pci/controller/pcie-mediatek-gen3.c | 49 ++++++++++++++++-----
> >   1 file changed, 37 insertions(+), 12 deletions(-)
> > 
> > diff --git a/drivers/pci/controller/pcie-mediatek-gen3.c b/drivers/pci/controller/pcie-mediatek-gen3.c
> > index 4859bd875bc4..9842617795a9 100644
> > --- a/drivers/pci/controller/pcie-mediatek-gen3.c
> > +++ b/drivers/pci/controller/pcie-mediatek-gen3.c
> > @@ -100,14 +100,21 @@
> >   #define PCIE_ATR_TLP_TYPE_MEM		PCIE_ATR_TLP_TYPE(0)
> >   #define PCIE_ATR_TLP_TYPE_IO		PCIE_ATR_TLP_TYPE(2)
> > +#define MAX_NUM_PHY_RSTS		1
> > +
> >   struct mtk_gen3_pcie;
> >   /**
> >    * struct mtk_pcie_soc - differentiate between host generations
> >    * @power_up: pcie power_up callback
> > + * @phy_resets: phy reset lines SoC data.
> >    */
> >   struct mtk_pcie_soc {
> >   	int (*power_up)(struct mtk_gen3_pcie *pcie);
> > +	struct {
> > +		const char *id[MAX_NUM_PHY_RSTS];
> > +		int num_rsts;
> 
> Well, it's just two chars after all, so "num_resets" looks better imo.

ack, fine. Naming is always hard :)

> 
> > +	} phy_resets;
> >   };
> >   /**
> > @@ -128,7 +135,7 @@ struct mtk_msi_set {
> >    * @base: IO mapped register base
> >    * @reg_base: physical register base
> >    * @mac_reset: MAC reset control
> > - * @phy_reset: PHY reset control
> > + * @phy_resets: PHY reset controllers
> >    * @phy: PHY controller block
> >    * @clks: PCIe clocks
> >    * @num_clks: PCIe clocks count for this port
> > @@ -148,7 +155,7 @@ struct mtk_gen3_pcie {
> >   	void __iomem *base;
> >   	phys_addr_t reg_base;
> >   	struct reset_control *mac_reset;
> > -	struct reset_control *phy_reset;
> > +	struct reset_control_bulk_data phy_resets[MAX_NUM_PHY_RSTS];
> >   	struct phy *phy;
> >   	struct clk_bulk_data *clks;
> >   	int num_clks;
> > @@ -790,8 +797,8 @@ static int mtk_pcie_parse_port(struct mtk_gen3_pcie *pcie)
> >   {
> >   	struct device *dev = pcie->dev;
> >   	struct platform_device *pdev = to_platform_device(dev);
> > +	int i, ret, num_rsts = pcie->soc->phy_resets.num_rsts; >   	struct resource *regs;
> > -	int ret;
> >   	regs = platform_get_resource_byname(pdev, IORESOURCE_MEM, "pcie-mac");
> >   	if (!regs)
> > @@ -804,12 +811,13 @@ static int mtk_pcie_parse_port(struct mtk_gen3_pcie *pcie)
> >   	pcie->reg_base = regs->start;
> > -	pcie->phy_reset = devm_reset_control_get_optional_exclusive(dev, "phy");
> > -	if (IS_ERR(pcie->phy_reset)) {
> > -		ret = PTR_ERR(pcie->phy_reset);
> > -		if (ret != -EPROBE_DEFER)
> > -			dev_err(dev, "failed to get PHY reset\n");
> > +	for (i = 0; i < num_rsts; i++)
> > +		pcie->phy_resets[i].id = pcie->soc->phy_resets.id[i];
> > +	ret = devm_reset_control_bulk_get_optional_shared(dev, num_rsts,
> > +							  pcie->phy_resets);
> 
> 92 columns is ok, you can use one line for that.

I usually prefer to stay below 79 column limit, but I do not have a strong
opinion about it. I will fix it and even all below.

Regards,
Lorenzo

> 
> > +	if (ret) {
> > +		dev_err(dev, "failed to get PHY bulk reset\n");
> >   		return ret;
> >   	}
> > @@ -846,7 +854,12 @@ static int mtk_pcie_power_up(struct mtk_gen3_pcie *pcie)
> >   	int err;
> >   	/* PHY power on and enable pipe clock */
> > -	reset_control_deassert(pcie->phy_reset);
> > +	err = reset_control_bulk_deassert(pcie->soc->phy_resets.num_rsts,
> > +					  pcie->phy_resets);
> > +	if (err) {
> > +		dev_err(dev, "failed to deassert PHYs\n");
> > +		return err;
> > +	}
> >   	err = phy_init(pcie->phy);
> >   	if (err) {
> > @@ -882,7 +895,8 @@ static int mtk_pcie_power_up(struct mtk_gen3_pcie *pcie)
> >   err_phy_on:
> >   	phy_exit(pcie->phy);
> >   err_phy_init:
> > -	reset_control_assert(pcie->phy_reset);
> > +	reset_control_bulk_assert(pcie->soc->phy_resets.num_rsts,
> > +				  pcie->phy_resets);
> 
> same here
> 
> >   	return err;
> >   }
> > @@ -897,7 +911,8 @@ static void mtk_pcie_power_down(struct mtk_gen3_pcie *pcie)
> >   	phy_power_off(pcie->phy);
> >   	phy_exit(pcie->phy);
> > -	reset_control_assert(pcie->phy_reset);
> > +	reset_control_bulk_assert(pcie->soc->phy_resets.num_rsts,
> > +				  pcie->phy_resets);
> 
> ditto
> 
> >   }
> >   static int mtk_pcie_setup(struct mtk_gen3_pcie *pcie)
> > @@ -912,7 +927,13 @@ static int mtk_pcie_setup(struct mtk_gen3_pcie *pcie)
> >   	 * The controller may have been left out of reset by the bootloader
> >   	 * so make sure that we get a clean start by asserting resets here.
> >   	 */
> > -	reset_control_assert(pcie->phy_reset);
> > +	reset_control_bulk_deassert(pcie->soc->phy_resets.num_rsts,
> > +				    pcie->phy_resets);
> 
> and again...
> 
> > +	usleep_range(5000, 10000);
> > +	reset_control_bulk_assert(pcie->soc->phy_resets.num_rsts,
> > +				  pcie->phy_resets);
> 
> .... :-)
> 
> Cheers,
> Angelo
> 
> > +	msleep(100);
> > +
> >   	reset_control_assert(pcie->mac_reset);
> >   	usleep_range(10, 20);
> > @@ -1090,6 +1111,10 @@ static const struct dev_pm_ops mtk_pcie_pm_ops = {
> >   static const struct mtk_pcie_soc mtk_pcie_soc_mt8192 = {
> >   	.power_up = mtk_pcie_power_up,
> > +	.phy_resets = {
> > +		.id[0] = "phy",
> > +		.num_rsts = 1,
> > +	},
> >   };
> >   static const struct of_device_id mtk_pcie_of_match[] = {
> 

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