Re: [PATCH v3 11/11] PCI: imx6: Add i.MX8Q PCIe support

From: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
To: Frank Li <Frank.Li@nxp.com>
Cc: "Richard Zhu" <hongxing.zhu@nxp.com>,
	"Lucas Stach" <l.stach@pengutronix.de>,
	"Lorenzo Pieralisi" <lpieralisi@kernel.org>,
	"Krzysztof Wilczyński" <kw@linux.com>,
	"Rob Herring" <robh@kernel.org>,
	"Bjorn Helgaas" <bhelgaas@google.com>,
	"Shawn Guo" <shawnguo@kernel.org>,
	"Sascha Hauer" <s.hauer@pengutronix.de>,
	"Pengutronix Kernel Team" <kernel@pengutronix.de>,
	"Fabio Estevam" <festevam@gmail.com>,
	"NXP Linux Team" <linux-imx@nxp.com>,
	"Philipp Zabel" <p.zabel@pengutronix.de>,
	"Liam Girdwood" <lgirdwood@gmail.com>,
	"Mark Brown" <broonie@kernel.org>,
	"Krzysztof Kozlowski" <krzysztof.kozlowski+dt@linaro.org>,
	"Conor Dooley" <conor+dt@kernel.org>,
	linux-pci@vger.kernel.org, imx@lists.linux.dev,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, bpf@vger.kernel.org,
	devicetree@vger.kernel.org
Subject: Re: [PATCH v3 11/11] PCI: imx6: Add i.MX8Q PCIe support
Date: Sat, 27 Apr 2024 17:17:36 +0530	[thread overview]
Message-ID: <20240427114736.GO1981@thinkpad> (raw)
In-Reply-To: <20240402-pci2_upstream-v3-11-803414bdb430@nxp.com>

On Tue, Apr 02, 2024 at 10:33:47AM -0400, Frank Li wrote:
> From: Richard Zhu <hongxing.zhu@nxp.com>
> 
> Add i.MX8Q (i.MX8QM, i.MX8QXP and i.MX8DXL) PCIe support.
> 

Add some info like IP version, PCIe Gen, how different the code support
comparted to previous SoCs etc...

> Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
> Signed-off-by: Frank Li <Frank.Li@nxp.com>
> ---
>  drivers/pci/controller/dwc/pcie-imx.c | 54 +++++++++++++++++++++++++++++++++++
>  1 file changed, 54 insertions(+)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-imx.c b/drivers/pci/controller/dwc/pcie-imx.c
> index 378808262d16b..af7c79e869e70 100644
> --- a/drivers/pci/controller/dwc/pcie-imx.c
> +++ b/drivers/pci/controller/dwc/pcie-imx.c
> @@ -30,6 +30,7 @@
>  #include <linux/interrupt.h>
>  #include <linux/reset.h>
>  #include <linux/phy/phy.h>
> +#include <linux/phy/pcie.h>
>  #include <linux/pm_domain.h>
>  #include <linux/pm_runtime.h>
>  
> @@ -81,6 +82,7 @@ enum imx_pcie_variants {
>  	IMX8MQ,
>  	IMX8MM,
>  	IMX8MP,
> +	IMX8Q,
>  	IMX95,
>  	IMX8MQ_EP,
>  	IMX8MM_EP,
> @@ -96,6 +98,7 @@ enum imx_pcie_variants {
>  #define IMX_PCIE_FLAG_HAS_PHY_RESET		BIT(5)
>  #define IMX_PCIE_FLAG_HAS_SERDES		BIT(6)
>  #define IMX_PCIE_FLAG_SUPPORT_64BIT		BIT(7)
> +#define IMX_PCIE_FLAG_CPU_ADDR_FIXUP		BIT(8)
>  
>  #define imx_check_flag(pci, val)     (pci->drvdata->flags & val)
>  
> @@ -132,6 +135,7 @@ struct imx_pcie {
>  	struct regmap		*iomuxc_gpr;
>  	u16			msi_ctrl;
>  	u32			controller_id;
> +	u32			local_addr;
>  	struct reset_control	*pciephy_reset;
>  	struct reset_control	*apps_reset;
>  	struct reset_control	*turnoff_reset;
> @@ -402,6 +406,10 @@ static void imx_pcie_configure_type(struct imx_pcie *imx_pcie)
>  	if (!drvdata->mode_mask[id])
>  		id = 0;
>  
> +	/* If mode_mask is 0, means use phy driver to set mode */
> +	if (!drvdata->mode_mask[id])
> +		return;

There is already a check above for 0 mode_mask. Please consolidate.

> +
>  	mask = drvdata->mode_mask[id];
>  	val = mode << (ffs(mask) - 1);
>  
> @@ -957,6 +965,7 @@ static void imx_pcie_ltssm_enable(struct device *dev)
>  	struct imx_pcie *imx_pcie = dev_get_drvdata(dev);
>  	const struct imx_pcie_drvdata *drvdata = imx_pcie->drvdata;
>  
> +	phy_set_speed(imx_pcie->phy, PCI_EXP_LNKCAP_SLS_2_5GB);
>  	if (drvdata->ltssm_mask)
>  		regmap_update_bits(imx_pcie->iomuxc_gpr, drvdata->ltssm_off, drvdata->ltssm_mask,
>  				   drvdata->ltssm_mask);
> @@ -969,6 +978,7 @@ static void imx_pcie_ltssm_disable(struct device *dev)
>  	struct imx_pcie *imx_pcie = dev_get_drvdata(dev);
>  	const struct imx_pcie_drvdata *drvdata = imx_pcie->drvdata;
>  
> +	phy_set_speed(imx_pcie->phy, 0);
>  	if (drvdata->ltssm_mask)
>  		regmap_update_bits(imx_pcie->iomuxc_gpr, drvdata->ltssm_off,
>  				   drvdata->ltssm_mask, 0);
> @@ -1104,6 +1114,12 @@ static int imx_pcie_host_init(struct dw_pcie_rp *pp)
>  			goto err_clk_disable;
>  		}
>  
> +		ret = phy_set_mode_ext(imx_pcie->phy, PHY_MODE_PCIE, PHY_MODE_PCIE_RC);
> +		if (ret) {
> +			dev_err(dev, "unable to set pcie PHY mode\n");
> +			goto err_phy_off;
> +		}

This is not i.MX8Q specific. Please add it in a separate patch.

> +
>  		ret = phy_power_on(imx_pcie->phy);
>  		if (ret) {
>  			dev_err(dev, "waiting for PHY ready timeout!\n");
> @@ -1154,6 +1170,28 @@ static void imx_pcie_host_exit(struct dw_pcie_rp *pp)
>  		regulator_disable(imx_pcie->vpcie);
>  }
>  
> +static u64 imx_pcie_cpu_addr_fixup(struct dw_pcie *pcie, u64 cpu_addr)
> +{
> +	struct imx_pcie *imx_pcie = to_imx_pcie(pcie);
> +	struct dw_pcie_ep *ep = &pcie->ep;
> +	struct dw_pcie_rp *pp = &pcie->pp;
> +	struct resource_entry *entry;
> +	unsigned int offset;
> +
> +	if (!(imx_pcie->drvdata->flags & IMX_PCIE_FLAG_CPU_ADDR_FIXUP))

This flag should be documented in the commit message.

> +		return cpu_addr;
> +
> +	if (imx_pcie->drvdata->mode == DW_PCIE_EP_TYPE) {
> +		offset = ep->phys_base;
> +	} else {
> +		entry = resource_list_first_type(&pp->bridge->windows,
> +						 IORESOURCE_MEM);

Check for NULL entry.

> +		offset = entry->res->start;
> +	}
> +
> +	return (cpu_addr + imx_pcie->local_addr - offset);
> +}
> +
>  static const struct dw_pcie_host_ops imx_pcie_host_ops = {
>  	.init = imx_pcie_host_init,
>  	.deinit = imx_pcie_host_exit,
> @@ -1162,6 +1200,7 @@ static const struct dw_pcie_host_ops imx_pcie_host_ops = {
>  static const struct dw_pcie_ops dw_pcie_ops = {
>  	.start_link = imx_pcie_start_link,
>  	.stop_link = imx_pcie_stop_link,
> +	.cpu_addr_fixup = imx_pcie_cpu_addr_fixup,
>  };
>  
>  static void imx_pcie_ep_init(struct dw_pcie_ep *ep)
> @@ -1481,6 +1520,12 @@ static int imx_pcie_probe(struct platform_device *pdev)
>  					     "Failed to get PCIEPHY reset control\n");
>  	}
>  
> +	if (imx_check_flag(imx_pcie, IMX_PCIE_FLAG_CPU_ADDR_FIXUP)) {
> +		ret = of_property_read_u32(node, "fsl,local-address", &imx_pcie->local_addr);
> +		if (ret)
> +			return dev_err_probe(dev, ret, "Failed to get local-address");

Is it OK to continue?

- Mani

-- 
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