[PATCH 7/7] PCI: layerscape: Add power management support

From: Zhiqiang Hou
Date: Mon Sep 07 2020 - 01:46:33 EST

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In reply to: Zhiqiang Hou: "[PATCH 5/7] dt-bindings: pci: layerscape-pci: Update the description of SCFG property"
Next in thread: Zhiqiang Hou: "[PATCH 1/7] PCI: dwc: Fix a bug of the case dw_pci->ops is NULL"
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From: Hou Zhiqiang <Zhiqiang.Hou@xxxxxxx>

Add PME_Turn_Off/PME_TO_Ack handshake sequence, and finally
put the PCIe controller into D3 state after the L2/L3 ready
state transition process completion.

Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou@xxxxxxx>
---
drivers/pci/controller/dwc/pci-layerscape.c | 384 ++++++++++++++++++-
drivers/pci/controller/dwc/pcie-designware.h | 1 +
2 files changed, 383 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/controller/dwc/pci-layerscape.c b/drivers/pci/controller/dwc/pci-layerscape.c
index be404c16bcbe..ca9ea07f77c1 100644
--- a/drivers/pci/controller/dwc/pci-layerscape.c
+++ b/drivers/pci/controller/dwc/pci-layerscape.c
@@ -3,13 +3,16 @@
* PCIe host controller driver for Freescale Layerscape SoCs
*
* Copyright (C) 2014 Freescale Semiconductor.
+ * Copyright 2020 NXP
*
* Author: Minghuan Lian <Minghuan.Lian@xxxxxxxxxxxxx>
*/

+#include <linux/delay.h>
#include <linux/kernel.h>
#include <linux/interrupt.h>
#include <linux/init.h>
+#include <linux/iopoll.h>
#include <linux/of_pci.h>
#include <linux/of_platform.h>
#include <linux/of_irq.h>
@@ -27,17 +30,66 @@
#define PCIE_ABSERR 0x8d0 /* Bridge Slave Error Response Register */
#define PCIE_ABSERR_SETTING 0x9401 /* Forward error of non-posted request */

+#define PCIE_PM_SCR 0x44
+#define PCIE_PM_SCR_PMEPS_D0 0x0
+#define PCIE_PM_SCR_PMEPS_D3 0x3
+
+#define PCIE_LNKCTL 0x80 /* PCIe link ctrl Register */
+
+/* PF Message Command Register */
+#define LS_PCIE_PF_MCR 0x2c
+#define PF_MCR_PTOMR BIT(0)
+#define PF_MCR_EXL2S BIT(1)
+
+/* LS1021A PEXn PM Write Control Register */
+#define SCFG_PEXPMWRCR(idx) (0x5c + (idx) * 0x64)
+#define PMXMTTURNOFF BIT(31)
+#define SCFG_PEXSFTRSTCR 0x190
+#define PEXSR(idx) BIT(idx)
+
+/* LS1043A PEX PME control register */
+#define SCFG_PEXPMECR 0x144
+#define PEXPME(idx) BIT(31 - (idx) * 4)
+
+/* LS1043A PEX LUT debug register */
+#define LS_PCIE_LDBG 0x7fc
+#define LDBG_SR BIT(30)
+#define LDBG_WE BIT(31)
+
#define PCIE_IATU_NUM 6

+#define LS_PCIE_IS_L2(v) \
+ (((v) & PORT_LOGIC_LTSSM_STATE_MASK) == PORT_LOGIC_LTSSM_STATE_L2)
+
+struct ls_pcie;
+
+struct ls_pcie_host_pm_ops {
+ int (*pm_init)(struct ls_pcie *pcie);
+ void (*send_turn_off_message)(struct ls_pcie *pcie);
+ void (*exit_from_l2)(struct ls_pcie *pcie);
+};
+
struct ls_pcie_drvdata {
+ const u32 pf_off;
+ const u32 lut_off;
const struct dw_pcie_host_ops *ops;
+ const struct ls_pcie_host_pm_ops *pm_ops;
};

struct ls_pcie {
struct dw_pcie *pci;
const struct ls_pcie_drvdata *drvdata;
+ void __iomem *pf_base;
+ void __iomem *lut_base;
+ bool big_endian;
+ bool ep_presence;
+ bool pm_support;
+ struct regmap *scfg;
+ int index;
};

+#define ls_pcie_lut_readl_addr(addr) ls_pcie_lut_readl(pcie, addr)
+#define ls_pcie_pf_readl_addr(addr) ls_pcie_pf_readl(pcie, addr)
#define to_ls_pcie(x) dev_get_drvdata((x)->dev)

static bool ls_pcie_is_bridge(struct ls_pcie *pcie)
@@ -86,6 +138,208 @@ static void ls_pcie_fix_error_response(struct ls_pcie *pcie)
iowrite32(PCIE_ABSERR_SETTING, pci->dbi_base + PCIE_ABSERR);
}

+static u32 ls_pcie_lut_readl(struct ls_pcie *pcie, u32 off)
+{
+ if (pcie->big_endian)
+ return ioread32be(pcie->lut_base + off);
+
+ return ioread32(pcie->lut_base + off);
+}
+
+static void ls_pcie_lut_writel(struct ls_pcie *pcie, u32 off, u32 val)
+{
+ if (pcie->big_endian)
+ return iowrite32be(val, pcie->lut_base + off);
+
+ return iowrite32(val, pcie->lut_base + off);
+
+}
+
+static u32 ls_pcie_pf_readl(struct ls_pcie *pcie, u32 off)
+{
+ if (pcie->big_endian)
+ return ioread32be(pcie->pf_base + off);
+
+ return ioread32(pcie->pf_base + off);
+}
+
+static void ls_pcie_pf_writel(struct ls_pcie *pcie, u32 off, u32 val)
+{
+ if (pcie->big_endian)
+ return iowrite32be(val, pcie->pf_base + off);
+
+ return iowrite32(val, pcie->pf_base + off);
+
+}
+
+static void ls_pcie_send_turnoff_msg(struct ls_pcie *pcie)
+{
+ u32 val;
+ int ret;
+
+ val = ls_pcie_pf_readl(pcie, LS_PCIE_PF_MCR);
+ val |= PF_MCR_PTOMR;
+ ls_pcie_pf_writel(pcie, LS_PCIE_PF_MCR, val);
+
+ ret = readx_poll_timeout(ls_pcie_pf_readl_addr, LS_PCIE_PF_MCR,
+ val, !(val & PF_MCR_PTOMR), 100, 10000);
+ if (ret)
+ dev_info(pcie->pci->dev, "poll turn off message timeout\n");
+}
+
+static void ls1021a_pcie_send_turnoff_msg(struct ls_pcie *pcie)
+{
+ u32 val;
+
+ if (!pcie->scfg) {
+ dev_dbg(pcie->pci->dev, "SYSCFG is NULL\n");
+ return;
+ }
+
+ /* Send Turn_off message */
+ regmap_read(pcie->scfg, SCFG_PEXPMWRCR(pcie->index), &val);
+ val |= PMXMTTURNOFF;
+ regmap_write(pcie->scfg, SCFG_PEXPMWRCR(pcie->index), val);
+
+ mdelay(10);
+
+ /* Clear Turn_off message */
+ regmap_read(pcie->scfg, SCFG_PEXPMWRCR(pcie->index), &val);
+ val &= ~PMXMTTURNOFF;
+ regmap_write(pcie->scfg, SCFG_PEXPMWRCR(pcie->index), val);
+}
+
+static void ls1043a_pcie_send_turnoff_msg(struct ls_pcie *pcie)
+{
+ u32 val;
+
+ if (!pcie->scfg) {
+ dev_dbg(pcie->pci->dev, "SYSCFG is NULL\n");
+ return;
+ }
+
+ /* Send Turn_off message */
+ regmap_read(pcie->scfg, SCFG_PEXPMECR, &val);
+ val |= PEXPME(pcie->index);
+ regmap_write(pcie->scfg, SCFG_PEXPMECR, val);
+
+ mdelay(10);
+
+ /* Clear Turn_off message */
+ regmap_read(pcie->scfg, SCFG_PEXPMECR, &val);
+ val &= ~PEXPME(pcie->index);
+ regmap_write(pcie->scfg, SCFG_PEXPMECR, val);
+}
+
+static void ls_pcie_exit_from_l2(struct ls_pcie *pcie)
+{
+ u32 val;
+ int ret;
+
+ val = ls_pcie_pf_readl(pcie, LS_PCIE_PF_MCR);
+ val |= PF_MCR_EXL2S;
+ ls_pcie_pf_writel(pcie, LS_PCIE_PF_MCR, val);
+
+ ret = readx_poll_timeout(ls_pcie_pf_readl_addr, LS_PCIE_PF_MCR,
+ val, !(val & PF_MCR_EXL2S), 100, 10000);
+ if (ret)
+ dev_info(pcie->pci->dev, "poll exit L2 state timeout\n");
+}
+
+static void ls_pcie_retrain_link(struct ls_pcie *pcie)
+{
+ struct dw_pcie *pci = pcie->pci;
+ u32 val;
+
+ val = dw_pcie_readw_dbi(pci, PCIE_LNKCTL);
+ val |= PCI_EXP_LNKCTL_RL;
+ dw_pcie_writew_dbi(pci, PCIE_LNKCTL, val);
+}
+
+static void ls1021a_pcie_exit_from_l2(struct ls_pcie *pcie)
+{
+ u32 val;
+
+ regmap_read(pcie->scfg, SCFG_PEXSFTRSTCR, &val);
+ val |= PEXSR(pcie->index);
+ regmap_write(pcie->scfg, SCFG_PEXSFTRSTCR, val);
+
+ regmap_read(pcie->scfg, SCFG_PEXSFTRSTCR, &val);
+ val &= ~PEXSR(pcie->index);
+ regmap_write(pcie->scfg, SCFG_PEXSFTRSTCR, val);
+
+ mdelay(1);
+
+ ls_pcie_retrain_link(pcie);
+}
+static void ls1043a_pcie_exit_from_l2(struct ls_pcie *pcie)
+{
+ u32 val;
+
+ val = ls_pcie_lut_readl(pcie, LS_PCIE_LDBG);
+ val |= LDBG_WE;
+ ls_pcie_lut_writel(pcie, LS_PCIE_LDBG, val);
+
+ val = ls_pcie_lut_readl(pcie, LS_PCIE_LDBG);
+ val |= LDBG_SR;
+ ls_pcie_lut_writel(pcie, LS_PCIE_LDBG, val);
+
+ val = ls_pcie_lut_readl(pcie, LS_PCIE_LDBG);
+ val &= ~LDBG_SR;
+ ls_pcie_lut_writel(pcie, LS_PCIE_LDBG, val);
+
+ val = ls_pcie_lut_readl(pcie, LS_PCIE_LDBG);
+ val &= ~LDBG_WE;
+ ls_pcie_lut_writel(pcie, LS_PCIE_LDBG, val);
+
+ mdelay(1);
+
+ ls_pcie_retrain_link(pcie);
+}
+
+static int ls1021a_pcie_pm_init(struct ls_pcie *pcie)
+{
+ struct device *dev = pcie->pci->dev;
+ u32 index[2];
+ int ret;
+
+ pcie->scfg = syscon_regmap_lookup_by_phandle(dev->of_node,
+ "fsl,pcie-scfg");
+ if (IS_ERR(pcie->scfg)) {
+ ret = PTR_ERR(pcie->scfg);
+ dev_err(dev, "No syscfg phandle specified\n");
+ pcie->scfg = NULL;
+ return ret;
+ }
+
+ ret = of_property_read_u32_array(dev->of_node, "fsl,pcie-scfg",
+ index, 2);
+ if (ret) {
+ pcie->scfg = NULL;
+ return ret;
+ }
+
+ pcie->index = index[1];
+
+ return 0;
+}
+
+static int ls_pcie_pm_init(struct ls_pcie *pcie)
+{
+ return 0;
+}
+
+static void ls_pcie_set_dstate(struct ls_pcie *pcie, u32 dstate)
+{
+ struct dw_pcie *pci = pcie->pci;
+ u32 val;
+
+ val = dw_pcie_readw_dbi(pci, PCIE_PM_SCR);
+ val &= ~PCI_PM_CTRL_STATE_MASK;
+ val |= dstate;
+ dw_pcie_writew_dbi(pci, PCIE_PM_SCR, val);
+}
+
static int ls_pcie_host_init(struct pcie_port *pp)
{
struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
@@ -133,20 +387,52 @@ static int ls_pcie_msi_host_init(struct pcie_port *pp)
return 0;
}

+static struct ls_pcie_host_pm_ops ls1021a_pcie_host_pm_ops = {
+ .pm_init = &ls1021a_pcie_pm_init,
+ .send_turn_off_message = &ls1021a_pcie_send_turnoff_msg,
+ .exit_from_l2 = &ls1021a_pcie_exit_from_l2,
+};
+
+static struct ls_pcie_host_pm_ops ls1043a_pcie_host_pm_ops = {
+ .pm_init = &ls1021a_pcie_pm_init,
+ .send_turn_off_message = &ls1043a_pcie_send_turnoff_msg,
+ .exit_from_l2 = &ls1043a_pcie_exit_from_l2,
+};
+
+static struct ls_pcie_host_pm_ops ls_pcie_host_pm_ops = {
+ .pm_init = &ls_pcie_pm_init,
+ .send_turn_off_message = &ls_pcie_send_turnoff_msg,
+ .exit_from_l2 = &ls_pcie_exit_from_l2,
+};
+
static const struct dw_pcie_host_ops ls_pcie_host_ops = {
.host_init = ls_pcie_host_init,
.msi_host_init = ls_pcie_msi_host_init,
};

+static const struct ls_pcie_drvdata ls1021a_drvdata = {
+ .ops = &ls_pcie_host_ops,
+ .pm_ops = &ls1021a_pcie_host_pm_ops,
+};
+
+static const struct ls_pcie_drvdata ls1043a_drvdata = {
+ .ops = &ls_pcie_host_ops,
+ .lut_off = 0x10000,
+ .pm_ops = &ls1043a_pcie_host_pm_ops,
+};
+
static const struct ls_pcie_drvdata layerscape_drvdata = {
.ops = &ls_pcie_host_ops,
+ .lut_off = 0x80000,
+ .pf_off = 0xc0000,
+ .pm_ops = &ls_pcie_host_pm_ops,
};

static const struct of_device_id ls_pcie_of_match[] = {
{ .compatible = "fsl,ls1012a-pcie", .data = &layerscape_drvdata },
- { .compatible = "fsl,ls1021a-pcie", .data = &layerscape_drvdata },
+ { .compatible = "fsl,ls1021a-pcie", .data = &ls1021a_drvdata },
{ .compatible = "fsl,ls1028a-pcie", .data = &layerscape_drvdata },
- { .compatible = "fsl,ls1043a-pcie", .data = &layerscape_drvdata },
+ { .compatible = "fsl,ls1043a-pcie", .data = &ls1043a_drvdata },
{ .compatible = "fsl,ls1046a-pcie", .data = &layerscape_drvdata },
{ .compatible = "fsl,ls2080a-pcie", .data = &layerscape_drvdata },
{ .compatible = "fsl,ls2085a-pcie", .data = &layerscape_drvdata },
@@ -170,6 +456,15 @@ static int __init ls_add_pcie_port(struct ls_pcie *pcie)
return ret;
}

+ if (dw_pcie_link_up(pci)) {
+ dev_dbg(pci->dev, "Endpoint is present\n");
+ pcie->ep_presence = true;
+ }
+
+ if (pcie->drvdata->pm_ops && pcie->drvdata->pm_ops->pm_init &&
+ !pcie->drvdata->pm_ops->pm_init(pcie))
+ pcie->pm_support = true;
+
return 0;
}

@@ -200,6 +495,14 @@ static int __init ls_pcie_probe(struct platform_device *pdev)
if (IS_ERR(pci->dbi_base))
return PTR_ERR(pci->dbi_base);

+ pcie->big_endian = of_property_read_bool(dev->of_node, "big-endian");
+
+ if (pcie->drvdata->lut_off)
+ pcie->lut_base = pci->dbi_base + pcie->drvdata->lut_off;
+
+ if (pcie->drvdata->pf_off)
+ pcie->pf_base = pci->dbi_base + pcie->drvdata->pf_off;
+
if (!ls_pcie_is_bridge(pcie))
return -ENODEV;

@@ -212,11 +515,88 @@ static int __init ls_pcie_probe(struct platform_device *pdev)
return 0;
}

+static bool ls_pcie_pm_check(struct ls_pcie *pcie)
+{
+ if (!pcie->ep_presence) {
+ dev_dbg(pcie->pci->dev, "Endpoint isn't present\n");
+ return false;
+ }
+
+ if (!pcie->pm_support)
+ return false;
+
+ return true;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int ls_pcie_suspend_noirq(struct device *dev)
+{
+ struct ls_pcie *pcie = dev_get_drvdata(dev);
+ struct dw_pcie *pci = pcie->pci;
+ u32 val;
+ int ret;
+
+ if (!ls_pcie_pm_check(pcie))
+ return 0;
+
+ pcie->drvdata->pm_ops->send_turn_off_message(pcie);
+
+ /* 10ms timeout to check L2 ready */
+ ret = readl_poll_timeout(pci->dbi_base + PCIE_PORT_DEBUG0,
+ val, LS_PCIE_IS_L2(val), 100, 10000);
+ if (ret) {
+ dev_err(dev, "PCIe link enter L2 timeout! ltssm = 0x%x\n", val);
+ return ret;
+ }
+
+ ls_pcie_set_dstate(pcie, PCIE_PM_SCR_PMEPS_D3);
+
+ return 0;
+}
+
+static int ls_pcie_resume_noirq(struct device *dev)
+{
+ struct ls_pcie *pcie = dev_get_drvdata(dev);
+ struct dw_pcie *pci = pcie->pci;
+ int ret;
+
+ if (!ls_pcie_pm_check(pcie))
+ return 0;
+
+ ls_pcie_set_dstate(pcie, PCIE_PM_SCR_PMEPS_D0);
+
+ pcie->drvdata->pm_ops->exit_from_l2(pcie);
+
+ /* delay 10ms to access EP */
+ mdelay(10);
+
+ ret = ls_pcie_host_init(&pci->pp);
+ if (ret) {
+ dev_err(dev, "ls_pcie_host_init failed! ret = 0x%x\n", ret);
+ return ret;
+ }
+
+ ret = dw_pcie_wait_for_link(pci);
+ if (ret) {
+ dev_err(dev, "wait link up timeout! ret = 0x%x\n", ret);
+ return ret;
+ }
+
+ return 0;
+}
+#endif /* CONFIG_PM_SLEEP */
+
+static const struct dev_pm_ops ls_pcie_pm_ops = {
+ SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(ls_pcie_suspend_noirq,
+ ls_pcie_resume_noirq)
+};
+
static struct platform_driver ls_pcie_driver = {
.driver = {
.name = "layerscape-pcie",
.of_match_table = ls_pcie_of_match,
.suppress_bind_attrs = true,
+ .pm = &ls_pcie_pm_ops,
},
};
builtin_platform_driver_probe(ls_pcie_driver, ls_pcie_probe);
diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
index f911760dcc69..1f2fd03d1eba 100644
--- a/drivers/pci/controller/dwc/pcie-designware.h
+++ b/drivers/pci/controller/dwc/pcie-designware.h
@@ -46,6 +46,7 @@
#define PCIE_PORT_DEBUG0 0x728
#define PORT_LOGIC_LTSSM_STATE_MASK 0x1f
#define PORT_LOGIC_LTSSM_STATE_L0 0x11
+#define PORT_LOGIC_LTSSM_STATE_L2 0x15
#define PCIE_PORT_DEBUG1 0x72C
#define PCIE_PORT_DEBUG1_LINK_UP BIT(4)
#define PCIE_PORT_DEBUG1_LINK_IN_TRAINING BIT(29)
--
2.17.1

Next message: Zhiqiang Hou: "[PATCH 1/7] PCI: dwc: Fix a bug of the case dw_pci->ops is NULL"
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In reply to: Zhiqiang Hou: "[PATCH 5/7] dt-bindings: pci: layerscape-pci: Update the description of SCFG property"
Next in thread: Zhiqiang Hou: "[PATCH 1/7] PCI: dwc: Fix a bug of the case dw_pci->ops is NULL"
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