Date:   Fri, 22 Dec 2017 02:49:50 -0500
From:   "Jingoo Han" <jingoohan1@...il.com>
To:     "'Jaehoon Chung'" <jh80.chung@...sung.com>,
        <linux-pci@...r.kernel.org>
Cc:     <linux-samsung-soc@...r.kernel.org>, <devicetree@...r.kernel.org>,
        <linux-kernel@...r.kernel.org>, <robh+dt@...nel.org>,
        <krzk@...nel.org>, <kgene@...nel.org>, <lorenzo.pieralisi@....com>
Subject: Re: [RFC 2/2] pci: dwc: pci-exynos: add the codes to support the exynos5433

On Thursday, December 21, 2017 9:21 PM, Jaehoon Chung wrote:
> On 12/22/2017 01:12 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@...sung.com>
> >> ---
> >>  ...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
> 
> Maybe, you're right. Because i didn't have Exynos5440 TRM, it's problem to
> me about updating other SoCs.
> I have checked almost all variants Exynos. They are using the LINKUP
> register as 0x74.
> 
> If i can get the exynos5440 TRM, it's much helpful to me. Is it possible?

I don't have Exynos5440 TRM.
Please ask other guys.

Best regards,
Jingoo Han

> 
> >
> >> +#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);
> >  	}
> >
> >
> >> +	/*
> >> +	 * 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?
> 
> It's possible to keep, but if it has to keep, then it needs to distinguish
> between exynos5440 and other exynos.
> Although I already mentioned, i needs to get Exynos5440 TRM. :)
> 
> Best Regards,
> Jaehoon Chung
> 
> >
> > 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
> >
> >
> >
> >
> >

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