Re: [PATCH v6 11/12] PCI: qcom: Add Force GEN1 support

[Stanimir Varbanov]

Hi Ansuel,

Sorry that I didn't make this comment earlier.

The subject and description are misleading. The patch itself is not
forcing anything (the DT is filling the gen to 1), so please fix that.

On 6/10/20 7:06 PM, Ansuel Smith wrote:
> From: Sham Muthayyan <smuthayy@xxxxxxxxxxxxxx>
> 
> Add Force GEN1 support needed in some ipq8064 board that needs to limit
> some PCIe line to gen1 for some hardware limitation. This is set by the
> max-link-speed binding and needed by some soc based on ipq8064. (for
> example Netgear R7800 router)
> 
> Signed-off-by: Sham Muthayyan <smuthayy@xxxxxxxxxxxxxx>
> Signed-off-by: Ansuel Smith <ansuelsmth@xxxxxxxxx>
> Reviewed-by: Rob Herring <robh@xxxxxxxxxx>
> ---
>  drivers/pci/controller/dwc/pcie-qcom.c | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
> index 259b627bf890..c40921589122 100644
> --- a/drivers/pci/controller/dwc/pcie-qcom.c
> +++ b/drivers/pci/controller/dwc/pcie-qcom.c
> @@ -27,6 +27,7 @@
>  #include <linux/slab.h>
>  #include <linux/types.h>
>  
> +#include "../../pci.h"
>  #include "pcie-designware.h"
>  
>  #define PCIE20_PARF_SYS_CTRL			0x00
> @@ -99,6 +100,8 @@
>  #define PCIE20_v3_PARF_SLV_ADDR_SPACE_SIZE	0x358
>  #define SLV_ADDR_SPACE_SZ			0x10000000
>  
> +#define PCIE20_LNK_CONTROL2_LINK_STATUS2	0xa0
> +
>  #define DEVICE_TYPE_RC				0x4
>  
>  #define QCOM_PCIE_2_1_0_MAX_SUPPLY	3
> @@ -195,6 +198,7 @@ struct qcom_pcie {
>  	struct phy *phy;
>  	struct gpio_desc *reset;
>  	const struct qcom_pcie_ops *ops;
> +	int gen;
>  };
>  
>  #define to_qcom_pcie(x)		dev_get_drvdata((x)->dev)
> @@ -395,6 +399,11 @@ static int qcom_pcie_init_2_1_0(struct qcom_pcie *pcie)
>  	/* wait for clock acquisition */
>  	usleep_range(1000, 1500);
>  
> +	if (pcie->gen == 1) {
> +		val = readl(pci->dbi_base + PCIE20_LNK_CONTROL2_LINK_STATUS2);
> +		val |= PCI_EXP_LNKSTA_CLS_2_5GB;
> +		writel(val, pci->dbi_base + PCIE20_LNK_CONTROL2_LINK_STATUS2);
> +	}
>  
>  	/* Set the Max TLP size to 2K, instead of using default of 4K */
>  	writel(CFG_REMOTE_RD_REQ_BRIDGE_SIZE_2K,
> @@ -1397,6 +1406,10 @@ static int qcom_pcie_probe(struct platform_device *pdev)
>  		goto err_pm_runtime_put;
>  	}
>  
> +	pcie->gen = of_pci_get_max_link_speed(pdev->dev.of_node);
> +	if (pcie->gen < 0)
> +		pcie->gen = 2;
> +
>  	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "parf");
>  	pcie->parf = devm_ioremap_resource(dev, res);
>  	if (IS_ERR(pcie->parf)) {
> 

-- 
regards,
Stan