Commit a528d1a7 authored by Frank Li's avatar Frank Li Committed by Bjorn Helgaas
Browse files

PCI: imx6: Use DWC common suspend resume method 

Call common DWC suspend/resume function. Use DWC common iATU method to
send out PME_TURN_OFF message.

In old DWC implementations, PCIE_ATU_INHIBIT_PAYLOAD in iATU Ctrl2 register
is reserved, so the generic DWC implementation of sending the PME_Turn_Off
message using a dummy MMIO write cannot be used. Use the previous method to
kick off PME_TURN_OFF message for these platforms.

The System Reset Control (SRC) interface is used to toggle 'turnoff_reset'
to send PME_TURN_OFF and since the DWC implementation is used, it is not
needed now.

Replace the imx_pcie_stop_link() and imx_pcie_host_exit() by
dw_pcie_suspend_noirq() in imx_pcie_suspend_noirq().

Since dw_pcie_suspend_noirq() already does these, see below call stack:

  dw_pcie_suspend_noirq()
    dw_pcie_stop_link()
      imx_pcie_stop_link()
    pci->pp.ops->deinit()
      imx_pcie_host_exit()

Replace the imx_pcie_host_init(), dw_pcie_setup_rc() and
imx_pcie_start_link() by dw_pcie_resume_noirq() in imx_pcie_resume_noirq().

Since dw_pcie_resume_noirq() already does these, see below call stack:

  dw_pcie_resume_noirq()
    pci->pp.ops->init()
      imx_pcie_host_init()
    dw_pcie_setup_rc()
    dw_pcie_start_link()
      imx_pcie_start_link(;

Link: https://lore.kernel.org/r/20241126075702.4099164-9-hongxing.zhu@nxp.com


Signed-off-by: default avatarFrank Li <Frank.Li@nxp.com>
Signed-off-by: default avatarRichard Zhu <hongxing.zhu@nxp.com>
Signed-off-by: default avatarKrzysztof Wilczyński <kwilczynski@kernel.org>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
parent ec57335b

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

+35 −61
Original line number Diff line number Diff line
@@ -33,6 +33,7 @@ 
#include <linux/pm_domain.h>

#include <linux/pm_runtime.h>



#include "../../pci.h"

#include "pcie-designware.h"



#define IMX8MQ_GPR_PCIE_REF_USE_PAD		BIT(9)
@@ -111,19 +112,18 @@ struct imx_pcie_drvdata { 
	int (*init_phy)(struct imx_pcie *pcie);

	int (*enable_ref_clk)(struct imx_pcie *pcie, bool enable);

	int (*core_reset)(struct imx_pcie *pcie, bool assert);

	const struct dw_pcie_host_ops *ops;

};



struct imx_pcie {

	struct dw_pcie		*pci;

	struct gpio_desc	*reset_gpiod;

	bool			link_is_up;

	struct clk_bulk_data	clks[IMX_PCIE_MAX_CLKS];

	struct regmap		*iomuxc_gpr;

	u16			msi_ctrl;

	u32			controller_id;

	struct reset_control	*pciephy_reset;

	struct reset_control	*apps_reset;

	struct reset_control	*turnoff_reset;

	u32			tx_deemph_gen1;

	u32			tx_deemph_gen2_3p5db;

	u32			tx_deemph_gen2_6db;
@@ -908,13 +908,11 @@ static int imx_pcie_start_link(struct dw_pcie *pci) 
		dev_info(dev, "Link: Only Gen1 is enabled\n");

	}



	imx_pcie->link_is_up = true;

	tmp = dw_pcie_readw_dbi(pci, offset + PCI_EXP_LNKSTA);

	dev_info(dev, "Link up, Gen%i\n", tmp & PCI_EXP_LNKSTA_CLS);

	return 0;



err_reset_phy:

	imx_pcie->link_is_up = false;

	dev_dbg(dev, "PHY DEBUG_R0=0x%08x DEBUG_R1=0x%08x\n",

		dw_pcie_readl_dbi(pci, PCIE_PORT_DEBUG0),

		dw_pcie_readl_dbi(pci, PCIE_PORT_DEBUG1));
@@ -1033,9 +1031,31 @@ static u64 imx_pcie_cpu_addr_fixup(struct dw_pcie *pcie, u64 cpu_addr) 
	return cpu_addr - entry->offset;

}



/*

 * In old DWC implementations, PCIE_ATU_INHIBIT_PAYLOAD in iATU Ctrl2

 * register is reserved, so the generic DWC implementation of sending the

 * PME_Turn_Off message using a dummy MMIO write cannot be used.

 */

static void imx_pcie_pme_turn_off(struct dw_pcie_rp *pp)

{

	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);

	struct imx_pcie *imx_pcie = to_imx_pcie(pci);



	regmap_set_bits(imx_pcie->iomuxc_gpr, IOMUXC_GPR12, IMX6SX_GPR12_PCIE_PM_TURN_OFF);

	regmap_clear_bits(imx_pcie->iomuxc_gpr, IOMUXC_GPR12, IMX6SX_GPR12_PCIE_PM_TURN_OFF);



	usleep_range(PCIE_PME_TO_L2_TIMEOUT_US/10, PCIE_PME_TO_L2_TIMEOUT_US);

}



static const struct dw_pcie_host_ops imx_pcie_host_ops = {

	.init = imx_pcie_host_init,

	.deinit = imx_pcie_host_exit,

	.pme_turn_off = imx_pcie_pme_turn_off,

};



static const struct dw_pcie_host_ops imx_pcie_host_dw_pme_ops = {

	.init = imx_pcie_host_init,

	.deinit = imx_pcie_host_exit,

};



static const struct dw_pcie_ops dw_pcie_ops = {
@@ -1176,43 +1196,6 @@ static int imx_add_pcie_ep(struct imx_pcie *imx_pcie, 
	return 0;

}



static void imx_pcie_pm_turnoff(struct imx_pcie *imx_pcie)

{

	struct device *dev = imx_pcie->pci->dev;



	/* Some variants have a turnoff reset in DT */

	if (imx_pcie->turnoff_reset) {

		reset_control_assert(imx_pcie->turnoff_reset);

		reset_control_deassert(imx_pcie->turnoff_reset);

		goto pm_turnoff_sleep;

	}



	/* Others poke directly at IOMUXC registers */

	switch (imx_pcie->drvdata->variant) {

	case IMX6SX:

	case IMX6QP:

		regmap_update_bits(imx_pcie->iomuxc_gpr, IOMUXC_GPR12,

				IMX6SX_GPR12_PCIE_PM_TURN_OFF,

				IMX6SX_GPR12_PCIE_PM_TURN_OFF);

		regmap_update_bits(imx_pcie->iomuxc_gpr, IOMUXC_GPR12,

				IMX6SX_GPR12_PCIE_PM_TURN_OFF, 0);

		break;

	default:

		dev_err(dev, "PME_Turn_Off not implemented\n");

		return;

	}



	/*

	 * Components with an upstream port must respond to

	 * PME_Turn_Off with PME_TO_Ack but we can't check.

	 *

	 * The standard recommends a 1-10ms timeout after which to

	 * proceed anyway as if acks were received.

	 */

pm_turnoff_sleep:

	usleep_range(1000, 10000);

}



static void imx_pcie_msi_save_restore(struct imx_pcie *imx_pcie, bool save)

{

	u8 offset;
@@ -1236,7 +1219,6 @@ static void imx_pcie_msi_save_restore(struct imx_pcie *imx_pcie, bool save) 
static int imx_pcie_suspend_noirq(struct device *dev)

{

	struct imx_pcie *imx_pcie = dev_get_drvdata(dev);

	struct dw_pcie_rp *pp = &imx_pcie->pci->pp;



	if (!(imx_pcie->drvdata->flags & IMX_PCIE_FLAG_SUPPORTS_SUSPEND))

		return 0;
@@ -1251,9 +1233,7 @@ static int imx_pcie_suspend_noirq(struct device *dev) 
		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 dw_pcie_suspend_noirq(imx_pcie->pci);

	}



	return 0;
@@ -1263,7 +1243,6 @@ static int imx_pcie_resume_noirq(struct device *dev) 
{

	int ret;

	struct imx_pcie *imx_pcie = dev_get_drvdata(dev);

	struct dw_pcie_rp *pp = &imx_pcie->pci->pp;



	if (!(imx_pcie->drvdata->flags & IMX_PCIE_FLAG_SUPPORTS_SUSPEND))

		return 0;
@@ -1283,17 +1262,12 @@ static int imx_pcie_resume_noirq(struct device *dev) 
		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);

		ret = dw_pcie_resume_noirq(imx_pcie->pci);

		if (ret)

			return ret;

		imx_pcie_msi_save_restore(imx_pcie, false);

		dw_pcie_setup_rc(pp);



		if (imx_pcie->link_is_up)

			imx_pcie_start_link(imx_pcie->pci);

	}

	imx_pcie_msi_save_restore(imx_pcie, false);



	return 0;

}
@@ -1325,11 +1299,15 @@ static int imx_pcie_probe(struct platform_device *pdev) 


	pci->dev = dev;

	pci->ops = &dw_pcie_ops;

	pci->pp.ops = &imx_pcie_host_ops;



	imx_pcie->pci = pci;

	imx_pcie->drvdata = of_device_get_match_data(dev);



	if (imx_pcie->drvdata->ops)

		pci->pp.ops = imx_pcie->drvdata->ops;

	else

		pci->pp.ops = &imx_pcie_host_dw_pme_ops;



	/* Find the PHY if one is defined, only imx7d uses it */

	np = of_parse_phandle(node, "fsl,imx7d-pcie-phy", 0);

	if (np) {
@@ -1399,13 +1377,6 @@ static int imx_pcie_probe(struct platform_device *pdev) 
		break;

	}



	/* Grab turnoff reset */

	imx_pcie->turnoff_reset = devm_reset_control_get_optional_exclusive(dev, "turnoff");

	if (IS_ERR(imx_pcie->turnoff_reset)) {

		dev_err(dev, "Failed to get TURNOFF reset control\n");

		return PTR_ERR(imx_pcie->turnoff_reset);

	}



	if (imx_pcie->drvdata->gpr) {

	/* Grab GPR config register range */

		imx_pcie->iomuxc_gpr =
@@ -1484,6 +1455,7 @@ static int imx_pcie_probe(struct platform_device *pdev) 
		if (ret < 0)

			return ret;

	} else {

		pci->pp.use_atu_msg = true;

		ret = dw_pcie_host_init(&pci->pp);

		if (ret < 0)

			return ret;
@@ -1548,6 +1520,7 @@ static const struct imx_pcie_drvdata drvdata[] = { 
		.init_phy = imx6sx_pcie_init_phy,

		.enable_ref_clk = imx6sx_pcie_enable_ref_clk,

		.core_reset = imx6sx_pcie_core_reset,

		.ops = &imx_pcie_host_ops,

	},

	[IMX6QP] = {

		.variant = IMX6QP,
@@ -1565,6 +1538,7 @@ static const struct imx_pcie_drvdata drvdata[] = { 
		.init_phy = imx_pcie_init_phy,

		.enable_ref_clk = imx6q_pcie_enable_ref_clk,

		.core_reset = imx6qp_pcie_core_reset,

		.ops = &imx_pcie_host_ops,

	},

	[IMX7D] = {

		.variant = IMX7D,