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

Lorenzo Bianconi
2024-06-27T07:03:38Z

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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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