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Commit 584078c8 authored by Yan He's avatar Yan He
Browse files

msm: pcie: add the option for endpoint latency 



PCIe endpoint may require some latency after power on, before PCIe
Root Complex (RC) de-asserts PERST. Add the option here to support
this latency requirement.

Change-Id: I45df5a2306b6c3681fcd24af571552d346c6d87e
Signed-off-by: default avatarYan He <yanhe@codeaurora.org>
parent 94421a5e

Documentation/devicetree/bindings/pci/msm_pcie.txt

+3 −0
Original line number Diff line number Diff line
@@ -51,6 +51,8 @@ Optional Properties: 
  - qcom,msi-gicm-addr: MSI address for GICv2m.

  - qcom,msi-gicm-base: MSI IRQ base for GICv2m.

  - qcom,ext-ref-clk: The reference clock is external.

  - qcom,ep-latency: The time (unit: ms) to wait for the PCIe endpoint to become

    stable after power on, before de-assert the PERST to the endpoint.



Example:
@@ -113,4 +115,5 @@ Example: 
		qcom,msi-gicm-addr = <0xf9040040>;

		qcom,msi-gicm-base = <0x160>;

		qcom,ext-ref-clk;

		qcom,ep-latency = <100>;

	};

arch/arm/mach-msm/pcie.c

+13 −0
Original line number Diff line number Diff line
@@ -962,6 +962,9 @@ static int msm_pcie_enable(struct msm_pcie_dev_t *dev, u32 options) 
		goto link_fail;

	}



	if (dev->ep_latency)

		msleep(dev->ep_latency);



	/* de-assert PCIe reset link to bring EP out of reset */



	gpio_set_value(dev->gpio[MSM_PCIE_GPIO_PERST].num,
@@ -1243,6 +1246,16 @@ static int msm_pcie_probe(struct platform_device *pdev) 
	PCIE_DBG("ref clk is %s.\n",

		msm_pcie_dev[rc_idx].ext_ref_clk ? "external" : "internal");



	msm_pcie_dev[rc_idx].ep_latency = 0;

	ret = of_property_read_u32((&pdev->dev)->of_node,

				"qcom,ep-latency",

				&msm_pcie_dev[rc_idx].ep_latency);

	if (ret)

		PCIE_DBG("ep-latency does not exist.\n");

	else

		PCIE_DBG("ep-latency: 0x%x.\n",

				msm_pcie_dev[rc_idx].ep_latency);



	msm_pcie_dev[rc_idx].msi_gicm_addr = 0;

	msm_pcie_dev[rc_idx].msi_gicm_base = 0;

	ret = of_property_read_u32((&pdev->dev)->of_node,

arch/arm/mach-msm/pcie.h

+1 −0
Original line number Diff line number Diff line
@@ -175,6 +175,7 @@ struct msm_pcie_dev_t { 
	bool                         l1ss_supported;

	bool                         aux_clk_sync;

	bool                         ext_ref_clk;

	uint32_t                     ep_latency;



	uint32_t                     rc_idx;

	bool                         enumerated;