Re: [RFC 2/2] pci: dwc: pci-exynos: add the codes to support the exynos5433

From: Jingoo Han
Date: Thu Dec 21 2017 - 11:27:51 EST


On Thursday, December 21, 2017 11:13 AM, Jingoo Han wrote:
> On Thursday, December 21, 2017 7:14 AM, Jaehoon Chung wrote:
> >
> > Exynos5433 has the PCIe for WiFi.
> > Added the codes relevant to PCIe for supporting the exynos5433.
> > Also changed the binding documentation name to
> > 'samsung,exynos-pcie.txt'.
> > (It's not only exynos5440 anymore.)
> >
>
> I have no objection.
> However, I added some comments about Exynos5440.
>
> > Signed-off-by: Jaehoon Chung <jh80.chung@xxxxxxxxxxx>
> > ---
> > ...exynos5440-pcie.txt => samsung,exynos-pcie.txt} | 2 +-
> > drivers/pci/dwc/pci-exynos.c | 183
> ++++++++++++++++-----
> > 2 files changed, 144 insertions(+), 41 deletions(-)
> > rename Documentation/devicetree/bindings/pci/{samsung,exynos5440-
> pcie.txt
> > => samsung,exynos-pcie.txt} (97%)
> >
> > diff --git a/Documentation/devicetree/bindings/pci/samsung,exynos5440-
> > pcie.txt b/Documentation/devicetree/bindings/pci/samsung,exynos-pcie.txt
> > similarity index 97%
> > rename from Documentation/devicetree/bindings/pci/samsung,exynos5440-
> > pcie.txt
> > rename to Documentation/devicetree/bindings/pci/samsung,exynos-pcie.txt
> > index 34a11bfbfb60..958dcc150505 100644
> > --- a/Documentation/devicetree/bindings/pci/samsung,exynos5440-pcie.txt
> > +++ b/Documentation/devicetree/bindings/pci/samsung,exynos-pcie.txt
> > @@ -4,7 +4,7 @@ This PCIe host controller is based on the Synopsys
> > DesignWare PCIe IP
> > and thus inherits all the common properties defined in designware-
> > pcie.txt.
> >
> > Required properties:
> > -- compatible: "samsung,exynos5440-pcie"
> > +- compatible: "samsung,exynos5440-pcie" or "samsung,exynos5433-pcie"
> > - reg: base addresses and lengths of the PCIe controller,
> > the PHY controller, additional register for the PHY controller.
> > (Registers for the PHY controller are DEPRECATED.
> > diff --git a/drivers/pci/dwc/pci-exynos.c b/drivers/pci/dwc/pci-exynos.c
> > index 5596fdedbb94..8dee2e90347e 100644
> > --- a/drivers/pci/dwc/pci-exynos.c
> > +++ b/drivers/pci/dwc/pci-exynos.c
> > @@ -40,6 +40,8 @@
> > #define PCIE_IRQ_SPECIAL 0x008
> > #define PCIE_IRQ_EN_PULSE 0x00c
> > #define PCIE_IRQ_EN_LEVEL 0x010
> > +#define PCIE_SW_WAKE 0x018
> > +#define PCIE_BUS_EN BIT(1)
> > #define IRQ_MSI_ENABLE BIT(2)
> > #define PCIE_IRQ_EN_SPECIAL 0x014
> > #define PCIE_PWR_RESET 0x018
> > @@ -49,7 +51,8 @@
> > #define PCIE_NONSTICKY_RESET 0x024
> > #define PCIE_APP_INIT_RESET 0x028
> > #define PCIE_APP_LTSSM_ENABLE 0x02c
> > -#define PCIE_ELBI_RDLH_LINKUP 0x064
> > +#define PCIE_ELBI_RDLH_LINKUP 0x074
>
> The address of this register should be 0x064 for exynos5440.
> Howe about the following?
>
> +#define EXYNOS5440_PCIE_ELBI_RDLH_LINKUP 0x064
> +#define PCIE_ELBI_RDLH_LINKUP 0x074
>
> Or you can add the following.
>
> /* Exynos5440 PCIe ELBI registers */
> #define EXYNOS5440_PCIE_ELBI_RDLH_LINKUP 0x064
>
> > +#define PCIE_ELBI_XMLH_LINKUP BIT(4)
> > #define PCIE_ELBI_LTSSM_ENABLE 0x1
> > #define PCIE_ELBI_SLV_AWMISC 0x11c
> > #define PCIE_ELBI_SLV_ARMISC 0x120
> > @@ -94,6 +97,10 @@
> > #define PCIE_PHY_TRSV3_PD_TSV BIT(7)
> > #define PCIE_PHY_TRSV3_LVCC 0x31c
> >
> > +/* DBI register */
> > +#define PCIE_MISC_CONTROL_1_OFF 0x8BC
> > +#define DBI_RO_WR_EN BIT(0)
> > +
> > struct exynos_pcie_mem_res {
> > void __iomem *elbi_base; /* DT 0th resource: PCIe CTRL */
> > void __iomem *phy_base; /* DT 1st resource: PHY CTRL */
> > @@ -221,6 +228,96 @@ static const struct exynos_pcie_ops
> > exynos5440_pcie_ops = {
> > .deinit_clk_resources = exynos5440_pcie_deinit_clk_resources,
> > };
> >
> > +static int exynos5433_pcie_get_mem_resources(struct platform_device
> *pdev,
> > + struct exynos_pcie *ep)
> > +{
> > + struct dw_pcie *pci = ep->pci;
> > + struct device *dev = pci->dev;
> > + struct resource *res;
> > +
> > + ep->mem_res = devm_kzalloc(dev, sizeof(*ep->mem_res), GFP_KERNEL);
> > + if (!ep->mem_res)
> > + return -ENOMEM;
> > +
> > + /* External Local Bus interface(ELBI) Register */
> > + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "elbi");
> > + ep->mem_res->elbi_base = devm_ioremap_resource(&pdev->dev, res);
> > + if (IS_ERR(ep->mem_res->elbi_base))
> > + return PTR_ERR(ep->mem_res->elbi_base);
> > +
> > + /* Data Bus Interface(DBI) Register */
> > + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dbi");
> > + pci->dbi_base = devm_ioremap_resource(&pdev->dev, res);
> > + if (IS_ERR(pci->dbi_base))
> > + return PTR_ERR(pci->dbi_base);
> > +
> > + return 0;
> > +}
> > +
> > +static int exynos5433_pcie_get_clk_resources(struct exynos_pcie *ep)
> > +{
> > + struct dw_pcie *pci = ep->pci;
> > + struct device *dev = pci->dev;
> > +
> > + ep->clk_res = devm_kzalloc(dev, sizeof(*ep->clk_res), GFP_KERNEL);
> > + if (!ep->clk_res)
> > + return -ENOMEM;
> > +
> > + ep->clk_res->clk = devm_clk_get(dev, "pcie");
> > + if (IS_ERR(ep->clk_res->clk)) {
> > + dev_err(dev, "Failed to get pcie rc clock\n");
> > + return PTR_ERR(ep->clk_res->clk);
> > + }
> > +
> > + ep->clk_res->bus_clk = devm_clk_get(dev, "pcie_bus");
> > + if (IS_ERR(ep->clk_res->bus_clk)) {
> > + dev_err(dev, "Failed to get pcie bus clock\n");
> > + return PTR_ERR(ep->clk_res->bus_clk);
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +static void exynos5433_pcie_deinit_clk_resources(struct exynos_pcie
*ep)
> > +{
> > + clk_disable_unprepare(ep->clk_res->bus_clk);
> > + clk_disable_unprepare(ep->clk_res->clk);
> > +}
> > +
> > +
> > +static int exynos5433_pcie_init_clk_resources(struct exynos_pcie *ep)
> > +{
> > + struct dw_pcie *pci = ep->pci;
> > + struct device *dev = pci->dev;
> > + int ret;
> > +
> > + ret = clk_prepare_enable(ep->clk_res->clk);
> > + if (ret) {
> > + dev_err(dev, "cannot enable pcie rc clock");
> > + return ret;
> > + }
> > +
> > + ret = clk_prepare_enable(ep->clk_res->bus_clk);
> > + if (ret) {
> > + dev_err(dev, "cannot enable pcie bus clock");
> > + goto err_bus_clk;
> > + }
> > +
> > + return 0;
> > +
> > +err_bus_clk:
> > + clk_disable_unprepare(ep->clk_res->clk);
> > +
> > + return ret;
> > +}
> > +
> > +static const struct exynos_pcie_ops exynos5433_pcie_ops = {
> > + .get_mem_resources = exynos5433_pcie_get_mem_resources,
> > + .get_clk_resources = exynos5433_pcie_get_clk_resources,
> > + .init_clk_resources = exynos5433_pcie_init_clk_resources,
> > + .deinit_clk_resources = exynos5433_pcie_deinit_clk_resources,
> > +};
> > +
> > static void exynos_pcie_writel(void __iomem *base, u32 val, u32 reg)
> > {
> > writel(val, base + reg);
> > @@ -279,7 +376,9 @@ static void exynos_pcie_deassert_core_reset(struct
> > exynos_pcie *ep)
> > exynos_pcie_writel(ep->mem_res->elbi_base, 1, PCIE_NONSTICKY_RESET);
> > exynos_pcie_writel(ep->mem_res->elbi_base, 1, PCIE_APP_INIT_RESET);
> > exynos_pcie_writel(ep->mem_res->elbi_base, 0, PCIE_APP_INIT_RESET);
> > - exynos_pcie_writel(ep->mem_res->block_base, 1, PCIE_PHY_MAC_RESET);
> > + if (ep->mem_res->block_base)
> > + exynos_pcie_writel(ep->mem_res->block_base, 1,
> > + PCIE_PHY_MAC_RESET);
>
> Good.
>
> > }
> >
> > static void exynos_pcie_assert_phy_reset(struct exynos_pcie *ep)
> > @@ -413,9 +512,6 @@ static int exynos_pcie_establish_link(struct
> > exynos_pcie *ep)
> > if (ep->using_phy) {
> > phy_reset(ep->phy);
> >
> > - exynos_pcie_writel(ep->mem_res->elbi_base, 1,
> > - PCIE_PWR_RESET);
> > -
> > phy_power_on(ep->phy);
> > phy_init(ep->phy);
> > } else {
> > @@ -430,14 +526,16 @@ static int exynos_pcie_establish_link(struct
> > exynos_pcie *ep)
> > udelay(500);
> > exynos_pcie_writel(ep->mem_res->block_base, 0,
> > PCIE_PHY_COMMON_RESET);
> > + exynos_pcie_deassert_core_reset(ep);
> > }
> >
> > - /* pulse for common reset */
> > - exynos_pcie_writel(ep->mem_res->block_base, 1,
> > PCIE_PHY_COMMON_RESET);
> > - udelay(500);
> > - exynos_pcie_writel(ep->mem_res->block_base, 0,
> > PCIE_PHY_COMMON_RESET);
>
> These codes are also necessary for Exyno5440.
> How about moving these codes instead of removing them?
>
> @@ -430,14 +526,16 @@ static int exynos_pcie_establish_link(struct
> exynos_pcie *ep)
> udelay(500);
> exynos_pcie_writel(ep->mem_res->block_base, 0,
> PCIE_PHY_COMMON_RESET);
> + /* pulse for common reset */
> + exynos_pcie_writel(ep->mem_res->block_base, 1,
> + PCIE_PHY_COMMON_RESET);
> + udelay(500);
> + exynos_pcie_writel(ep->mem_res->block_base, 0,
> + PCIE_PHY_COMMON_RESET);
> + exynos_pcie_deassert_core_reset(ep);
> }

I checked that this code is duplicated.
So, you can remove this one.
Sorry for making you confused.

Best regards,
Jingoo Han

>
>
> > + /*
> > + * Enable DBI_RO_WR_EN bit.
> > + * - When set to 1, some RO and HWinit bits are wriatble from
> > + * the local application through the DBI.
> > + */
> > + dw_pcie_writel_dbi(pci, PCIE_MISC_CONTROL_1_OFF, DBI_RO_WR_EN);
> >
> > - exynos_pcie_deassert_core_reset(ep);
> > dw_pcie_setup_rc(pp);
> > exynos_pcie_assert_reset(ep);
> >
> > @@ -472,16 +570,6 @@ static void exynos_pcie_clear_irq_pulse(struct
> > exynos_pcie *ep)
> > exynos_pcie_writel(ep->mem_res->elbi_base, val, PCIE_IRQ_PULSE);
> > }
> >
> > -static void exynos_pcie_enable_irq_pulse(struct exynos_pcie *ep)
> > -{
> > - u32 val;
> > -
> > - /* enable INTX interrupt */
> > - val = IRQ_INTA_ASSERT | IRQ_INTB_ASSERT |
> > - IRQ_INTC_ASSERT | IRQ_INTD_ASSERT;
> > - exynos_pcie_writel(ep->mem_res->elbi_base, val, PCIE_IRQ_EN_PULSE);
> > -}
> > -
> > static irqreturn_t exynos_pcie_irq_handler(int irq, void *arg)
> > {
> > struct exynos_pcie *ep = arg;
> > @@ -513,9 +601,16 @@ static void exynos_pcie_msi_init(struct exynos_pcie
> > *ep)
> > exynos_pcie_writel(ep->mem_res->elbi_base, val, PCIE_IRQ_EN_LEVEL);
> > }
> >
> > -static void exynos_pcie_enable_interrupts(struct exynos_pcie *ep)
> > +static void exynos_pcie_enable_irq_pulse(struct exynos_pcie *ep)
> > {
> > - exynos_pcie_enable_irq_pulse(ep);
> > + u32 val;
> > +
> > + val = IRQ_INTA_ASSERT | IRQ_INTB_ASSERT |
> > + IRQ_INTC_ASSERT | IRQ_INTD_ASSERT;
> > + exynos_pcie_writel(ep->mem_res->elbi_base, val, PCIE_IRQ_EN_PULSE);
> > +
> > + exynos_pcie_writel(ep->mem_res->elbi_base, 0, PCIE_IRQ_EN_LEVEL);
> > + exynos_pcie_writel(ep->mem_res->elbi_base, 0, PCIE_IRQ_EN_SPECIAL);
>
> Good.
>
> >
> > if (IS_ENABLED(CONFIG_PCI_MSI))
> > exynos_pcie_msi_init(ep);
> > @@ -575,10 +670,8 @@ static int exynos_pcie_link_up(struct dw_pcie *pci)
> > u32 val;
> >
> > val = exynos_pcie_readl(ep->mem_res->elbi_base,
> > PCIE_ELBI_RDLH_LINKUP);
> > - if (val == PCIE_ELBI_LTSSM_ENABLE)
> > - return 1;
>
> Exynos5440 uses 'PCIE_ELBI_LTSSM_ENABLE'.
> Can you keep this code for Exyno5440?
>
> This register can be added as below.
>
> /* Exynos5440 PCIe ELBI registers */
> #define EXYNOS5440_PCIE_ELBI_RDLH_LINKUP 0x064
> #define EXYNOS5440_PCIE_ELBI_LTSSM_ENABLE BIT(0)
>
> Best regards,
> Jingoo Han
>
> >
> > - return 0;
> > + return (val & PCIE_ELBI_XMLH_LINKUP);
> > }
> >
> > static int exynos_pcie_host_init(struct pcie_port *pp)
> > @@ -587,7 +680,7 @@ static int exynos_pcie_host_init(struct pcie_port
> *pp)
> > struct exynos_pcie *ep = to_exynos_pcie(pci);
> >
> > exynos_pcie_establish_link(ep);
> > - exynos_pcie_enable_interrupts(ep);
> > + exynos_pcie_enable_irq_pulse(ep);
> >
> > return 0;
> > }
> > @@ -608,8 +701,11 @@ static int __init exynos_add_pcie_port(struct
> > exynos_pcie *ep,
> >
> > pp->irq = platform_get_irq(pdev, 1);
> > if (pp->irq < 0) {
> > - dev_err(dev, "failed to get irq\n");
> > - return pp->irq;
> > + pp->irq = platform_get_irq_byname(pdev, "intr");
> > + if (pp->irq < 0) {
> > + dev_err(dev, "failed to get irq\n");
> > + return pp->irq;
> > + }
> > }
> > ret = devm_request_irq(dev, pp->irq, exynos_pcie_irq_handler,
> > IRQF_SHARED, "exynos-pcie", ep);
> > @@ -678,13 +774,23 @@ static int __init exynos_pcie_probe(struct
> > platform_device *pdev)
> >
> > ep->reset_gpio = of_get_named_gpio(np, "reset-gpio", 0);
> >
> > - /* Assume that controller doesn't use the PHY framework */
> > - ep->using_phy = false;
> > + /*
> > + * In case of Exynos5440,
> > + * Assume that controller doesn't use the PHY frameork.
> > + * Other SoCs might be used the PHY framework.
> > + */
> > +
> > + if (of_device_is_compatible(np, "samsung,exynos5440-pcie"))
> > + ep->using_phy = false;
> >
> > - ep->phy = devm_of_phy_get(dev, np, NULL);
> > + ep->phy = devm_of_phy_get(dev, np, "pcie-phy");
> > if (IS_ERR(ep->phy)) {
> > if (PTR_ERR(ep->phy) == -EPROBE_DEFER)
> > return PTR_ERR(ep->phy);
> > + if (!of_device_is_compatible(np, "samsung,exynos5440-pcie"))
> > {
> > + dev_err(dev, "Can't find the pcie-phy\n");
> > + return PTR_ERR(ep->phy);
> > + }
> > dev_warn(dev, "Use the 'phy' property. Current DT of pci-
> > exynos was deprecated!!\n");
> > } else
> > ep->using_phy = true;
> > @@ -734,23 +840,20 @@ static int __exit exynos_pcie_remove(struct
> > platform_device *pdev)
> > static const struct of_device_id exynos_pcie_of_match[] = {
> > {
> > .compatible = "samsung,exynos5440-pcie",
> > - .data = &exynos5440_pcie_ops
> > + .data = &exynos5440_pcie_ops,
> > + }, {
> > + .compatible = "samsung,exynos5433-pcie",
> > + .data = &exynos5433_pcie_ops,
> > },
> > {},
> > };
> >
> > static struct platform_driver exynos_pcie_driver = {
> > + .probe = exynos_pcie_probe,
> > .remove = __exit_p(exynos_pcie_remove),
> > .driver = {
> > .name = "exynos-pcie",
> > .of_match_table = exynos_pcie_of_match,
> > },
> > };
> > -
> > -/* Exynos PCIe driver does not allow module unload */
> > -
> > -static int __init exynos_pcie_init(void)
> > -{
> > - return platform_driver_probe(&exynos_pcie_driver,
> > exynos_pcie_probe);
> > -}
> > -subsys_initcall(exynos_pcie_init);
> > +builtin_platform_driver(exynos_pcie_driver);
> > --
> > 2.15.1
>