Commit 7b86e0a5 authored by Bjorn Helgaas's avatar Bjorn Helgaas
Browse files

Merge branch 'pci/controller/imx6' 

- Fix suspend/resume support on i.MX6QDL, which has a hardware erratum that
  prevents use of L2 (Stefan Eichenberger)

* pci/controller/imx6:
  PCI: imx6: Fix suspend/resume support on i.MX6QDL
parents 2b4049d1 0a726f54

drivers/pci/controller/dwc/pci-imx6.c

+46 −11
Original line number Diff line number Diff line
@@ -82,6 +82,11 @@ enum imx_pcie_variants { 
#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)

/*

 * Because of ERR005723 (PCIe does not support L2 power down) we need to

 * workaround suspend resume on some devices which are affected by this errata.

 */

#define IMX_PCIE_FLAG_BROKEN_SUSPEND		BIT(9)



#define imx_check_flag(pci, val)	(pci->drvdata->flags & val)
@@ -1237,9 +1242,19 @@ static int imx_pcie_suspend_noirq(struct device *dev) 
		return 0;



	imx_pcie_msi_save_restore(imx_pcie, true);

	if (imx_check_flag(imx_pcie, IMX_PCIE_FLAG_BROKEN_SUSPEND)) {

		/*

		 * The minimum for a workaround would be to set PERST# and to

		 * set the PCIE_TEST_PD flag. However, we can also disable the

		 * clock which saves some power.

		 */

		imx_pcie_assert_core_reset(imx_pcie);

		imx_pcie->drvdata->enable_ref_clk(imx_pcie, false);

	} else {

		imx_pcie_pm_turnoff(imx_pcie);

		imx_pcie_stop_link(imx_pcie->pci);

		imx_pcie_host_exit(pp);

	}



	return 0;

}
@@ -1253,6 +1268,23 @@ static int imx_pcie_resume_noirq(struct device *dev) 
	if (!(imx_pcie->drvdata->flags & IMX_PCIE_FLAG_SUPPORTS_SUSPEND))

		return 0;



	if (imx_check_flag(imx_pcie, IMX_PCIE_FLAG_BROKEN_SUSPEND)) {

		ret = imx_pcie->drvdata->enable_ref_clk(imx_pcie, true);

		if (ret)

			return ret;

		ret = imx_pcie_deassert_core_reset(imx_pcie);

		if (ret)

			return ret;

		/*

		 * Using PCIE_TEST_PD seems to disable MSI and powers down the

		 * root complex. This is why we have to setup the rc again and

		 * why we have to restore the MSI register.

		 */

		ret = dw_pcie_setup_rc(&imx_pcie->pci->pp);

		if (ret)

			return ret;

		imx_pcie_msi_save_restore(imx_pcie, false);

	} else {

		ret = imx_pcie_host_init(pp);

		if (ret)

			return ret;
@@ -1261,6 +1293,7 @@ static int imx_pcie_resume_noirq(struct device *dev) 


		if (imx_pcie->link_is_up)

			imx_pcie_start_link(imx_pcie->pci);

	}



	return 0;

}
@@ -1485,7 +1518,9 @@ static const struct imx_pcie_drvdata drvdata[] = { 
	[IMX6Q] = {

		.variant = IMX6Q,

		.flags = IMX_PCIE_FLAG_IMX_PHY |

			 IMX_PCIE_FLAG_IMX_SPEED_CHANGE,

			 IMX_PCIE_FLAG_IMX_SPEED_CHANGE |

			 IMX_PCIE_FLAG_BROKEN_SUSPEND |

			 IMX_PCIE_FLAG_SUPPORTS_SUSPEND,

		.dbi_length = 0x200,

		.gpr = "fsl,imx6q-iomuxc-gpr",

		.clk_names = imx6q_clks,