diff mbox series

[RESEND,v2,5/5] PCI: imx6: Add the compliance tests mode support

Message ID 1634277941-6672-6-git-send-email-hongxing.zhu@nxp.com
State New
Headers show
Series PCI: imx6: refine codes and add compliance tests mode support | expand

Commit Message

Hongxing Zhu Oct. 15, 2021, 6:05 a.m. UTC
Refer to the system board signal Quality of PCIe archiecture PHY test
specification. Signal quality tests(for example: jitters,  differential
eye opening and so on ) can be executed with devices in the
polling.compliance state.

To let the device support polling.compliance stat, the clocks and powers
shouldn't be turned off when the probe of device driver is failed.

Based on CLB(Compliance Load Board) Test Fixture and so on test
equipments, the PHY link would be down during the compliance tests.
Refer to this scenario, add the i.MX PCIe compliance tests mode enable
support, and keep the clocks and powers on, and finish the driver probe
without error return.

Use the "pci_imx6.compliance=1" in kernel command line to enable the
compliance tests mode.

Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
---
 drivers/pci/controller/dwc/pci-imx6.c | 32 ++++++++++++++++++++-------
 1 file changed, 24 insertions(+), 8 deletions(-)

Comments

Lucas Stach Oct. 15, 2021, 6:28 p.m. UTC | #1
Am Freitag, dem 15.10.2021 um 14:05 +0800 schrieb Richard Zhu:
> Refer to the system board signal Quality of PCIe archiecture PHY test
> specification. Signal quality tests(for example: jitters,  differential
> eye opening and so on ) can be executed with devices in the
> polling.compliance state.
> 
> To let the device support polling.compliance stat, the clocks and powers
> shouldn't be turned off when the probe of device driver is failed.
> 
> Based on CLB(Compliance Load Board) Test Fixture and so on test
> equipments, the PHY link would be down during the compliance tests.
> Refer to this scenario, add the i.MX PCIe compliance tests mode enable
> support, and keep the clocks and powers on, and finish the driver probe
> without error return.
> 
> Use the "pci_imx6.compliance=1" in kernel command line to enable the
> compliance tests mode.
> 
> Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
> ---
>  drivers/pci/controller/dwc/pci-imx6.c | 32 ++++++++++++++++++++-------
>  1 file changed, 24 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
> index d6a5d99ffa52..e861a516d517 100644
> --- a/drivers/pci/controller/dwc/pci-imx6.c
> +++ b/drivers/pci/controller/dwc/pci-imx6.c
> @@ -143,6 +143,10 @@ struct imx6_pcie {
>  #define PHY_RX_OVRD_IN_LO_RX_DATA_EN		BIT(5)
>  #define PHY_RX_OVRD_IN_LO_RX_PLL_EN		BIT(3)
>  
> +static bool imx6_pcie_cmp_mode;
> +module_param_named(compliance, imx6_pcie_cmp_mode, bool, 0644);
> +MODULE_PARM_DESC(compliance, "i.MX PCIe compliance test mode (1=compliance test mode enabled)");
> +
>  static int pcie_phy_poll_ack(struct imx6_pcie *imx6_pcie, bool exp_val)
>  {
>  	struct dw_pcie *pci = imx6_pcie->pci;
> @@ -812,10 +816,12 @@ static int imx6_pcie_start_link(struct dw_pcie *pci)
>  	 * started in Gen2 mode, there is a possibility the devices on the
>  	 * bus will not be detected at all.  This happens with PCIe switches.
>  	 */
> -	tmp = dw_pcie_readl_dbi(pci, offset + PCI_EXP_LNKCAP);
> -	tmp &= ~PCI_EXP_LNKCAP_SLS;
> -	tmp |= PCI_EXP_LNKCAP_SLS_2_5GB;
> -	dw_pcie_writel_dbi(pci, offset + PCI_EXP_LNKCAP, tmp);
> +	if (!imx6_pcie_cmp_mode) {
> +		tmp = dw_pcie_readl_dbi(pci, offset + PCI_EXP_LNKCAP);
> +		tmp &= ~PCI_EXP_LNKCAP_SLS;
> +		tmp |= PCI_EXP_LNKCAP_SLS_2_5GB;
> +		dw_pcie_writel_dbi(pci, offset + PCI_EXP_LNKCAP, tmp);
> +	}
>  
>  	/* Start LTSSM. */
>  	imx6_pcie_ltssm_enable(dev);
> @@ -876,9 +882,12 @@ static int imx6_pcie_start_link(struct dw_pcie *pci)
>  		dw_pcie_readl_dbi(pci, PCIE_PORT_DEBUG0),
>  		dw_pcie_readl_dbi(pci, PCIE_PORT_DEBUG1));
>  	imx6_pcie_reset_phy(imx6_pcie);

Is it correct to reset the PHY here when in compliance test mode?

> -	imx6_pcie_clk_disable(imx6_pcie);
> -	if (imx6_pcie->vpcie && regulator_is_enabled(imx6_pcie->vpcie) > 0)
> -		regulator_disable(imx6_pcie->vpcie);
> +	if (!imx6_pcie_cmp_mode) {
> +		imx6_pcie_clk_disable(imx6_pcie);
> +		if (imx6_pcie->vpcie
> +		    && regulator_is_enabled(imx6_pcie->vpcie) > 0)
> +			regulator_disable(imx6_pcie->vpcie);
> +	}
>  	return ret;
>  }
>  
> @@ -1183,8 +1192,15 @@ static int imx6_pcie_probe(struct platform_device *pdev)
>  		return ret;
>  
>  	ret = dw_pcie_host_init(&pci->pp);
> -	if (ret < 0)
> +	if (ret < 0) {
> +		if (imx6_pcie_cmp_mode) {
> +			dev_info(dev, "Driver loaded with compliance test mode enabled.\n");
> +			ret = 0;
> +		} else {
> +			dev_err(dev, "Unable to add pcie port.\n");
> +		}
>  		return ret; 
> +	}
>  
>  	if (pci_msi_enabled()) {
>  		u8 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_MSI);
Hongxing Zhu Oct. 19, 2021, 8:12 a.m. UTC | #2
> -----Original Message-----
> From: Lucas Stach <l.stach@pengutronix.de>
> Sent: Saturday, October 16, 2021 2:29 AM
> To: Richard Zhu <hongxing.zhu@nxp.com>; bhelgaas@google.com;
> lorenzo.pieralisi@arm.com
> Cc: linux-pci@vger.kernel.org; dl-linux-imx <linux-imx@nxp.com>;
> linux-arm-kernel@lists.infradead.org; linux-kernel@vger.kernel.org;
> kernel@pengutronix.de
> Subject: Re: [RESEND v2 5/5] PCI: imx6: Add the compliance tests mode
> support
> 
> Am Freitag, dem 15.10.2021 um 14:05 +0800 schrieb Richard Zhu:
> > Refer to the system board signal Quality of PCIe archiecture PHY test
> > specification. Signal quality tests(for example: jitters,
> > differential eye opening and so on ) can be executed with devices in
> > the polling.compliance state.
> >
> > To let the device support polling.compliance stat, the clocks and
> > powers shouldn't be turned off when the probe of device driver is failed.
> >
> > Based on CLB(Compliance Load Board) Test Fixture and so on test
> > equipments, the PHY link would be down during the compliance tests.
> > Refer to this scenario, add the i.MX PCIe compliance tests mode enable
> > support, and keep the clocks and powers on, and finish the driver
> > probe without error return.
> >
> > Use the "pci_imx6.compliance=1" in kernel command line to enable the
> > compliance tests mode.
> >
> > Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
> > ---
> >  drivers/pci/controller/dwc/pci-imx6.c | 32
> > ++++++++++++++++++++-------
> >  1 file changed, 24 insertions(+), 8 deletions(-)
> >
> > diff --git a/drivers/pci/controller/dwc/pci-imx6.c
> > b/drivers/pci/controller/dwc/pci-imx6.c
> > index d6a5d99ffa52..e861a516d517 100644
> > --- a/drivers/pci/controller/dwc/pci-imx6.c
> > +++ b/drivers/pci/controller/dwc/pci-imx6.c
> > @@ -143,6 +143,10 @@ struct imx6_pcie {
> >  #define PHY_RX_OVRD_IN_LO_RX_DATA_EN		BIT(5)
> >  #define PHY_RX_OVRD_IN_LO_RX_PLL_EN		BIT(3)
> >
> > +static bool imx6_pcie_cmp_mode;
> > +module_param_named(compliance, imx6_pcie_cmp_mode, bool, 0644);
> > +MODULE_PARM_DESC(compliance, "i.MX PCIe compliance test mode
> > +(1=compliance test mode enabled)");
> > +
> >  static int pcie_phy_poll_ack(struct imx6_pcie *imx6_pcie, bool
> > exp_val)  {
> >  	struct dw_pcie *pci = imx6_pcie->pci; @@ -812,10 +816,12 @@ static
> > int imx6_pcie_start_link(struct dw_pcie *pci)
> >  	 * started in Gen2 mode, there is a possibility the devices on the
> >  	 * bus will not be detected at all.  This happens with PCIe switches.
> >  	 */
> > -	tmp = dw_pcie_readl_dbi(pci, offset + PCI_EXP_LNKCAP);
> > -	tmp &= ~PCI_EXP_LNKCAP_SLS;
> > -	tmp |= PCI_EXP_LNKCAP_SLS_2_5GB;
> > -	dw_pcie_writel_dbi(pci, offset + PCI_EXP_LNKCAP, tmp);
> > +	if (!imx6_pcie_cmp_mode) {
> > +		tmp = dw_pcie_readl_dbi(pci, offset + PCI_EXP_LNKCAP);
> > +		tmp &= ~PCI_EXP_LNKCAP_SLS;
> > +		tmp |= PCI_EXP_LNKCAP_SLS_2_5GB;
> > +		dw_pcie_writel_dbi(pci, offset + PCI_EXP_LNKCAP, tmp);
> > +	}
> >
> >  	/* Start LTSSM. */
> >  	imx6_pcie_ltssm_enable(dev);
> > @@ -876,9 +882,12 @@ static int imx6_pcie_start_link(struct dw_pcie
> *pci)
> >  		dw_pcie_readl_dbi(pci, PCIE_PORT_DEBUG0),
> >  		dw_pcie_readl_dbi(pci, PCIE_PORT_DEBUG1));
> >  	imx6_pcie_reset_phy(imx6_pcie);
> 
> Is it correct to reset the PHY here when in compliance test mode?
[Richard Zhu] It doesn't matter. PHY reset just let the PHY enter into a dedicated stat after link is down.
This wouldn't impact the compliance tests mode later.

Best Regards
Richard Zhu

> 
> > -	imx6_pcie_clk_disable(imx6_pcie);
> > -	if (imx6_pcie->vpcie && regulator_is_enabled(imx6_pcie->vpcie) > 0)
> > -		regulator_disable(imx6_pcie->vpcie);
> > +	if (!imx6_pcie_cmp_mode) {
> > +		imx6_pcie_clk_disable(imx6_pcie);
> > +		if (imx6_pcie->vpcie
> > +		    && regulator_is_enabled(imx6_pcie->vpcie) > 0)
> > +			regulator_disable(imx6_pcie->vpcie);
> > +	}
> >  	return ret;
> >  }
> >
> > @@ -1183,8 +1192,15 @@ static int imx6_pcie_probe(struct
> platform_device *pdev)
> >  		return ret;
> >
> >  	ret = dw_pcie_host_init(&pci->pp);
> > -	if (ret < 0)
> > +	if (ret < 0) {
> > +		if (imx6_pcie_cmp_mode) {
> > +			dev_info(dev, "Driver loaded with compliance test mode
> enabled.\n");
> > +			ret = 0;
> > +		} else {
> > +			dev_err(dev, "Unable to add pcie port.\n");
> > +		}
> >  		return ret;
> > +	}
> >
> >  	if (pci_msi_enabled()) {
> >  		u8 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_MSI);
>
diff mbox series

Patch

diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
index d6a5d99ffa52..e861a516d517 100644
--- a/drivers/pci/controller/dwc/pci-imx6.c
+++ b/drivers/pci/controller/dwc/pci-imx6.c
@@ -143,6 +143,10 @@  struct imx6_pcie {
 #define PHY_RX_OVRD_IN_LO_RX_DATA_EN		BIT(5)
 #define PHY_RX_OVRD_IN_LO_RX_PLL_EN		BIT(3)
 
+static bool imx6_pcie_cmp_mode;
+module_param_named(compliance, imx6_pcie_cmp_mode, bool, 0644);
+MODULE_PARM_DESC(compliance, "i.MX PCIe compliance test mode (1=compliance test mode enabled)");
+
 static int pcie_phy_poll_ack(struct imx6_pcie *imx6_pcie, bool exp_val)
 {
 	struct dw_pcie *pci = imx6_pcie->pci;
@@ -812,10 +816,12 @@  static int imx6_pcie_start_link(struct dw_pcie *pci)
 	 * started in Gen2 mode, there is a possibility the devices on the
 	 * bus will not be detected at all.  This happens with PCIe switches.
 	 */
-	tmp = dw_pcie_readl_dbi(pci, offset + PCI_EXP_LNKCAP);
-	tmp &= ~PCI_EXP_LNKCAP_SLS;
-	tmp |= PCI_EXP_LNKCAP_SLS_2_5GB;
-	dw_pcie_writel_dbi(pci, offset + PCI_EXP_LNKCAP, tmp);
+	if (!imx6_pcie_cmp_mode) {
+		tmp = dw_pcie_readl_dbi(pci, offset + PCI_EXP_LNKCAP);
+		tmp &= ~PCI_EXP_LNKCAP_SLS;
+		tmp |= PCI_EXP_LNKCAP_SLS_2_5GB;
+		dw_pcie_writel_dbi(pci, offset + PCI_EXP_LNKCAP, tmp);
+	}
 
 	/* Start LTSSM. */
 	imx6_pcie_ltssm_enable(dev);
@@ -876,9 +882,12 @@  static int imx6_pcie_start_link(struct dw_pcie *pci)
 		dw_pcie_readl_dbi(pci, PCIE_PORT_DEBUG0),
 		dw_pcie_readl_dbi(pci, PCIE_PORT_DEBUG1));
 	imx6_pcie_reset_phy(imx6_pcie);
-	imx6_pcie_clk_disable(imx6_pcie);
-	if (imx6_pcie->vpcie && regulator_is_enabled(imx6_pcie->vpcie) > 0)
-		regulator_disable(imx6_pcie->vpcie);
+	if (!imx6_pcie_cmp_mode) {
+		imx6_pcie_clk_disable(imx6_pcie);
+		if (imx6_pcie->vpcie
+		    && regulator_is_enabled(imx6_pcie->vpcie) > 0)
+			regulator_disable(imx6_pcie->vpcie);
+	}
 	return ret;
 }
 
@@ -1183,8 +1192,15 @@  static int imx6_pcie_probe(struct platform_device *pdev)
 		return ret;
 
 	ret = dw_pcie_host_init(&pci->pp);
-	if (ret < 0)
+	if (ret < 0) {
+		if (imx6_pcie_cmp_mode) {
+			dev_info(dev, "Driver loaded with compliance test mode enabled.\n");
+			ret = 0;
+		} else {
+			dev_err(dev, "Unable to add pcie port.\n");
+		}
 		return ret;
+	}
 
 	if (pci_msi_enabled()) {
 		u8 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_MSI);