Re: [PATCH v2 04/11] PCI: dwc: pcie-kirin: add support for Kirin 970 PCIe controller

Mauro Carvalho Chehab
2021-02-03T17:50:12Z

Em Wed, 3 Feb 2021 08:34:21 -0600
Rob Herring <robh@kernel.org> escreveu:

> On Wed, Feb 3, 2021 at 1:02 AM Mauro Carvalho Chehab
> <mchehab+huawei@kernel.org> wrote:
> >
> > From: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> >
> > Add support for HiSilicon Kirin 970 (hi3670) SoC PCIe controller, based
> > on Synopsys DesignWare PCIe controller IP.
> >
> > [mchehab+huawei@kernel.org: fix merge conflicts]
> > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> > Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
> > ---
> > drivers/pci/controller/dwc/pcie-kirin.c | 723 +++++++++++++++++++++++-
> > 1 file changed, 707 insertions(+), 16 deletions(-)
> >
> > diff --git a/drivers/pci/controller/dwc/pcie-kirin.c b/drivers/pci/controller/dwc/pcie-kirin.c
> > index 026fd1e42a55..5925d2b345a8 100644
> > --- a/drivers/pci/controller/dwc/pcie-kirin.c
> > +++ b/drivers/pci/controller/dwc/pcie-kirin.c
> > @@ -29,6 +29,7 @@
> > #define to_kirin_pcie(x) dev_get_drvdata((x)->dev)
> >
> > #define REF_CLK_FREQ 100000000
> > +#define AXI_CLK_FREQ 207500000
> >
> > /* PCIe ELBI registers */
> > #define SOC_PCIECTRL_CTRL0_ADDR 0x000
> > @@ -60,6 +61,65 @@
> > #define PCIE_DEBOUNCE_PARAM 0xF0F400
> > #define PCIE_OE_BYPASS (0x3 << 28)
> >
> > +/* PCIe CTRL registers */
> > +#define SOC_PCIECTRL_CTRL0_ADDR 0x000
> > +#define SOC_PCIECTRL_CTRL1_ADDR 0x004
> > +#define SOC_PCIECTRL_CTRL7_ADDR 0x01c
> > +#define SOC_PCIECTRL_CTRL12_ADDR 0x030
> > +#define SOC_PCIECTRL_CTRL20_ADDR 0x050
> > +#define SOC_PCIECTRL_CTRL21_ADDR 0x054
> > +#define SOC_PCIECTRL_STATE0_ADDR 0x400
> > +
> > +/* PCIe PHY registers */
> > +#define SOC_PCIEPHY_CTRL0_ADDR 0x000
> > +#define SOC_PCIEPHY_CTRL1_ADDR 0x004
> > +#define SOC_PCIEPHY_CTRL2_ADDR 0x008
> > +#define SOC_PCIEPHY_CTRL3_ADDR 0x00c
> > +#define SOC_PCIEPHY_CTRL38_ADDR 0x0098
> > +#define SOC_PCIEPHY_STATE0_ADDR 0x400
> > +
> > +#define PCIE_LINKUP_ENABLE (0x8020)
> > +#define PCIE_ELBI_SLV_DBI_ENABLE (0x1 << 21)
> > +#define PCIE_LTSSM_ENABLE_BIT (0x1 << 11)
> > +#define PCIEPHY_RESET_BIT (0x1 << 17)
> > +#define PCIEPHY_PIPE_LINE0_RESET_BIT (0x1 << 19)
> > +
> > +#define PORT_MSI_CTRL_ADDR 0x820
> > +#define PORT_MSI_CTRL_UPPER_ADDR 0x824
> > +#define PORT_MSI_CTRL_INT0_ENABLE 0x828
>
> These are common DWC 'port logic' registers. I think the core DWC
> should handle them if not already.

I'll double-check if are there something that can be dropped.

>
> > +
> > +#define EYEPARAM_NOCFG 0xFFFFFFFF
> > +#define RAWLANEN_DIG_PCS_XF_TX_OVRD_IN_1 0x3001
> > +#define SUP_DIG_LVL_OVRD_IN 0xf
> > +#define LANEN_DIG_ASIC_TX_OVRD_IN_1 0x1002
> > +#define LANEN_DIG_ASIC_TX_OVRD_IN_2 0x1003
> > +
> > +/* kirin970 pciephy register */
> > +#define SOC_PCIEPHY_MMC1PLL_CTRL1 0xc04
> > +#define SOC_PCIEPHY_MMC1PLL_CTRL16 0xC40
> > +#define SOC_PCIEPHY_MMC1PLL_CTRL17 0xC44
> > +#define SOC_PCIEPHY_MMC1PLL_CTRL20 0xC50
> > +#define SOC_PCIEPHY_MMC1PLL_CTRL21 0xC54
> > +#define SOC_PCIEPHY_MMC1PLL_STAT0 0xE00
>
> This looks like it is almost all phy related. I think it should all be
> moved to a separate phy driver. Yes, we have some other PCI drivers
> controlling their phys directly where the phy registers are
> intermingled with the PCI host registers, but I think those either
> predate the phy subsystem or are really simple. I also have a dream to
> move all the phy control to the DWC core code.

Yeah, it sounds so. I'll check how hard would be to split this code
into a phy driver on a separate patch.

> > +struct kirin_pcie_ops {
> > + long (*get_resource)(struct kirin_pcie *kirin_pcie,
> > + struct platform_device *pdev);
> > + int (*power_on)(struct kirin_pcie *kirin_pcie);
>
> Never need to power off?

This driver uses devm_*() to allocate its resources, and doesn't
even uses builtin_platform_driver(kirin_pcie_driver) to register.

So, at the current state, it doesn't need a poweroff.

This "power_on" method is actually the device-specific part of
the probe: depending on the compatible, it either runs the Kirin 960
or the new Kirin 970 variant.

I'll try to double-check this when trying to split the PHY logic
from the driver.

> > +static long kirin970_pcie_get_resource(struct kirin_pcie *kirin_pcie,
> > + struct platform_device *pdev)
> > +{
> > + struct device *dev = &pdev->dev;
> > + struct resource *apb;
> > + struct resource *phy;
> > + struct resource *dbi;
> > + int ret;
> > +
> > + apb = platform_get_resource_byname(pdev, IORESOURCE_MEM, "apb");
> > + kirin_pcie->apb_base = devm_ioremap_resource(dev, apb);
> > + if (IS_ERR(kirin_pcie->apb_base))
> > + return PTR_ERR(kirin_pcie->apb_base);
> > +
> > + phy = platform_get_resource_byname(pdev, IORESOURCE_MEM, "phy");
> > + kirin_pcie->phy_base = devm_ioremap_resource(dev, phy);
> > + if (IS_ERR(kirin_pcie->phy_base))
> > + return PTR_ERR(kirin_pcie->phy_base);
> > +
> > + dbi = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dbi");
> > + kirin_pcie->pci->dbi_base = devm_ioremap_resource(dev, dbi);
>
> The DWC core handles this now.

Yes. This is addressed on this patch:

[PATCH v2 07/11] PCI: dwc: pcie-kirin: place common init code altogether

> > + if (IS_ERR(kirin_pcie->pci->dbi_base))
> > + return PTR_ERR(kirin_pcie->pci->dbi_base);
> > +
> > + kirin970_pcie_get_eyeparam(kirin_pcie);
> > +
> > + kirin_pcie->gpio_id_reset[0] = of_get_named_gpio(dev->of_node,
> > + "switch,reset-gpios", 0);
> > + if (kirin_pcie->gpio_id_reset[0] < 0)
> > + return -ENODEV;
> > +
> > + kirin_pcie->gpio_id_reset[1] = of_get_named_gpio(dev->of_node,
> > + "eth,reset-gpios", 0);
> > + if (kirin_pcie->gpio_id_reset[1] < 0)
> > + return -ENODEV;
> > +
> > + kirin_pcie->gpio_id_reset[2] = of_get_named_gpio(dev->of_node,
> > + "m_2,reset-gpios", 0);
> > + if (kirin_pcie->gpio_id_reset[2] < 0)
> > + return -ENODEV;
> > +
> > + kirin_pcie->gpio_id_reset[3] = of_get_named_gpio(dev->of_node,
> > + "mini1,reset-gpios", 0);
> > + if (kirin_pcie->gpio_id_reset[3] < 0)
>
> I've already explained how all this is wrong.

This patch:

[PATCH v2 09/11] PCI: dwc: pcie-kirin: allow using multiple reset GPIOs

Changes the above to, instead, get all the PERST# reset from "reset-gpios":

kirin_pcie->n_gpio_resets = of_gpio_named_count(np, "reset-gpios");
if (kirin_pcie->n_gpio_resets > MAX_GPIO_RESETS) {
dev_err(dev, "Too many GPIO resets!\n");
return -EINVAL;
}
for (i = 0; i < kirin_pcie->n_gpio_resets; i++) {
kirin_pcie->gpio_id_reset[i] = of_get_named_gpio(dev->of_node,
"reset-gpios", i);
if (kirin_pcie->gpio_id_reset[i] < 0)
return kirin_pcie->gpio_id_reset[i];

sprintf(name, "pcie_perst_%d", i);
kirin_pcie->reset_names[i] = devm_kstrdup_const(dev, name,
GFP_KERNEL);
if (!kirin_pcie->reset_names[i])
return -ENOMEM;
}

They're all handled altogether inside the driver.

> > @@ -431,6 +1124,9 @@ static int kirin_pcie_probe(struct platform_device *pdev)
> > return -EINVAL;
> > }
> >
> > + of_id = of_match_node(kirin_pcie_match, dev->of_node);
> > + ops = (struct kirin_pcie_ops *)of_id->data;
>
> of_device_get_match_data()

Ok.

Thanks,
Mauro