Merge branch 'pci/controller/dwc'

- Add an imx6 .host_deinit() callback so we can clean up things like
  regulators on probe failure or driver unload (Mark Brown)

- Add PCIE_PME_TO_L2_TIMEOUT_US value for controller drivers that need to
  manually synchronize power removal (Frank Li)

- Add generic dwc suspend/resume APIs (dw_pcie_suspend_noirq() and
  dw_pcie_resume_noirq()) to be called by controller driver suspend/resume
  ops, and a controller callback to send PME_Turn_Off (Frank Li)

- Add layerscape suspend/resume support, including manual
  PME_Turn_off/PME_TO_Ack handshake (Hou Zhiqiang, Frank Li)

* pci/controller/dwc:
  PCI: layerscape: Add power management support for ls1028a
  PCI: dwc: Implement generic suspend/resume functionality
  PCI: Add PCIE_PME_TO_L2_TIMEOUT_US L2 ready timeout value
  PCI: dwc: Provide deinit callback for i.MX

5 files changed, 237 insertions, 9 deletions

diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
index 27aaa2a6bf39..a18c20085e94 100644
--- a/drivers/pci/controller/dwc/pci-imx6.c
+++ b/drivers/pci/controller/dwc/pci-imx6.c
@@ -1040,6 +1040,7 @@ static void imx6_pcie_host_exit(struct dw_pcie_rp *pp)
 
 static const struct dw_pcie_host_ops imx6_pcie_host_ops = {
 	.host_init = imx6_pcie_host_init,
+	.host_deinit = imx6_pcie_host_exit,
 };
 
 static const struct dw_pcie_ops dw_pcie_ops = {
diff --git a/drivers/pci/controller/dwc/pci-layerscape.c b/drivers/pci/controller/dwc/pci-layerscape.c
index ed5fb492fe08..b931d597656f 100644
--- a/drivers/pci/controller/dwc/pci-layerscape.c
+++ b/drivers/pci/controller/dwc/pci-layerscape.c
@@ -8,9 +8,11 @@
  * Author: Minghuan Lian <Minghuan.Lian@freescale.com>
  */
 
+#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_address.h>
@@ -20,6 +22,7 @@
 #include <linux/mfd/syscon.h>
 #include <linux/regmap.h>
 
+#include "../../pci.h"
 #include "pcie-designware.h"
 
 /* PEX Internal Configuration Registers */
@@ -27,12 +30,26 @@
 #define PCIE_ABSERR		0x8d0 /* Bridge Slave Error Response Register */
 #define PCIE_ABSERR_SETTING	0x9401 /* Forward error of non-posted request */
 
+/* PF Message Command Register */
+#define LS_PCIE_PF_MCR		0x2c
+#define PF_MCR_PTOMR		BIT(0)
+#define PF_MCR_EXL2S		BIT(1)
+
 #define PCIE_IATU_NUM		6
 
+struct ls_pcie_drvdata {
+	const u32 pf_off;
+	bool pm_support;
+};
+
 struct ls_pcie {
 	struct dw_pcie *pci;
+	const struct ls_pcie_drvdata *drvdata;
+	void __iomem *pf_base;
+	bool big_endian;
 };
 
+#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)
@@ -73,6 +90,68 @@ static void ls_pcie_fix_error_response(struct ls_pcie *pcie)
 	iowrite32(PCIE_ABSERR_SETTING, pci->dbi_base + PCIE_ABSERR);
 }
 
+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)
+		iowrite32be(val, pcie->pf_base + off);
+	else
+		iowrite32(val, pcie->pf_base + off);
+}
+
+static void ls_pcie_send_turnoff_msg(struct dw_pcie_rp *pp)
+{
+	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+	struct ls_pcie *pcie = to_ls_pcie(pci);
+	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),
+				 PCIE_PME_TO_L2_TIMEOUT_US/10,
+				 PCIE_PME_TO_L2_TIMEOUT_US);
+	if (ret)
+		dev_err(pcie->pci->dev, "PME_Turn_off timeout\n");
+}
+
+static void ls_pcie_exit_from_l2(struct dw_pcie_rp *pp)
+{
+	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+	struct ls_pcie *pcie = to_ls_pcie(pci);
+	u32 val;
+	int ret;
+
+	/*
+	 * Set PF_MCR_EXL2S bit in LS_PCIE_PF_MCR register for the link
+	 * to exit L2 state.
+	 */
+	val = ls_pcie_pf_readl(pcie, LS_PCIE_PF_MCR);
+	val |= PF_MCR_EXL2S;
+	ls_pcie_pf_writel(pcie, LS_PCIE_PF_MCR, val);
+
+	/*
+	 * L2 exit timeout of 10ms is not defined in the specifications,
+	 * it was chosen based on empirical observations.
+	 */
+	ret = readx_poll_timeout(ls_pcie_pf_readl_addr, LS_PCIE_PF_MCR,
+				 val, !(val & PF_MCR_EXL2S),
+				 1000,
+				 10000);
+	if (ret)
+		dev_err(pcie->pci->dev, "L2 exit timeout\n");
+}
+
 static int ls_pcie_host_init(struct dw_pcie_rp *pp)
 {
 	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
@@ -91,18 +170,28 @@ static int ls_pcie_host_init(struct dw_pcie_rp *pp)
 
 static const struct dw_pcie_host_ops ls_pcie_host_ops = {
 	.host_init = ls_pcie_host_init,
+	.pme_turn_off = ls_pcie_send_turnoff_msg,
+};
+
+static const struct ls_pcie_drvdata ls1021a_drvdata = {
+	.pm_support = false,
+};
+
+static const struct ls_pcie_drvdata layerscape_drvdata = {
+	.pf_off = 0xc0000,
+	.pm_support = true,
 };
 
 static const struct of_device_id ls_pcie_of_match[] = {
-	{ .compatible = "fsl,ls1012a-pcie", },
-	{ .compatible = "fsl,ls1021a-pcie", },
-	{ .compatible = "fsl,ls1028a-pcie", },
-	{ .compatible = "fsl,ls1043a-pcie", },
-	{ .compatible = "fsl,ls1046a-pcie", },
-	{ .compatible = "fsl,ls2080a-pcie", },
-	{ .compatible = "fsl,ls2085a-pcie", },
-	{ .compatible = "fsl,ls2088a-pcie", },
-	{ .compatible = "fsl,ls1088a-pcie", },
+	{ .compatible = "fsl,ls1012a-pcie", .data = &layerscape_drvdata },
+	{ .compatible = "fsl,ls1021a-pcie", .data = &ls1021a_drvdata },
+	{ .compatible = "fsl,ls1028a-pcie", .data = &layerscape_drvdata },
+	{ .compatible = "fsl,ls1043a-pcie", .data = &ls1021a_drvdata },
+	{ .compatible = "fsl,ls1046a-pcie", .data = &layerscape_drvdata },
+	{ .compatible = "fsl,ls2080a-pcie", .data = &layerscape_drvdata },
+	{ .compatible = "fsl,ls2085a-pcie", .data = &layerscape_drvdata },
+	{ .compatible = "fsl,ls2088a-pcie", .data = &layerscape_drvdata },
+	{ .compatible = "fsl,ls1088a-pcie", .data = &layerscape_drvdata },
 	{ },
 };
 
@@ -121,6 +210,8 @@ static int ls_pcie_probe(struct platform_device *pdev)
 	if (!pci)
 		return -ENOMEM;
 
+	pcie->drvdata = of_device_get_match_data(dev);
+
 	pci->dev = dev;
 	pci->pp.ops = &ls_pcie_host_ops;
 
@@ -131,6 +222,10 @@ static int 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");
+
+	pcie->pf_base = pci->dbi_base + pcie->drvdata->pf_off;
+
 	if (!ls_pcie_is_bridge(pcie))
 		return -ENODEV;
 
@@ -139,12 +234,39 @@ static int ls_pcie_probe(struct platform_device *pdev)
 	return dw_pcie_host_init(&pci->pp);
 }
 
+static int ls_pcie_suspend_noirq(struct device *dev)
+{
+	struct ls_pcie *pcie = dev_get_drvdata(dev);
+
+	if (!pcie->drvdata->pm_support)
+		return 0;
+
+	return dw_pcie_suspend_noirq(pcie->pci);
+}
+
+static int ls_pcie_resume_noirq(struct device *dev)
+{
+	struct ls_pcie *pcie = dev_get_drvdata(dev);
+
+	if (!pcie->drvdata->pm_support)
+		return 0;
+
+	ls_pcie_exit_from_l2(&pcie->pci->pp);
+
+	return dw_pcie_resume_noirq(pcie->pci);
+}
+
+static const struct dev_pm_ops ls_pcie_pm_ops = {
+	NOIRQ_SYSTEM_SLEEP_PM_OPS(ls_pcie_suspend_noirq, ls_pcie_resume_noirq)
+};
+
 static struct platform_driver ls_pcie_driver = {
 	.probe = ls_pcie_probe,
 	.driver = {
 		.name = "layerscape-pcie",
 		.of_match_table = ls_pcie_of_match,
 		.suppress_bind_attrs = true,
+		.pm = &ls_pcie_pm_ops,
 	},
 };
 builtin_platform_driver(ls_pcie_driver);
diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
index cf61733bf78d..5c8cbc3afae4 100644
--- a/drivers/pci/controller/dwc/pcie-designware-host.c
+++ b/drivers/pci/controller/dwc/pcie-designware-host.c
@@ -8,6 +8,7 @@
  * Author: Jingoo Han <jg1.han@samsung.com>
  */
 
+#include <linux/iopoll.h>
 #include <linux/irqchip/chained_irq.h>
 #include <linux/irqdomain.h>
 #include <linux/msi.h>
@@ -16,6 +17,7 @@
 #include <linux/pci_regs.h>
 #include <linux/platform_device.h>
 
+#include "../../pci.h"
 #include "pcie-designware.h"
 
 static struct pci_ops dw_pcie_ops;
@@ -812,3 +814,72 @@ int dw_pcie_setup_rc(struct dw_pcie_rp *pp)
 	return 0;
 }
 EXPORT_SYMBOL_GPL(dw_pcie_setup_rc);
+
+int dw_pcie_suspend_noirq(struct dw_pcie *pci)
+{
+	u8 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
+	u32 val;
+	int ret;
+
+	/*
+	 * If L1SS is supported, then do not put the link into L2 as some
+	 * devices such as NVMe expect low resume latency.
+	 */
+	if (dw_pcie_readw_dbi(pci, offset + PCI_EXP_LNKCTL) & PCI_EXP_LNKCTL_ASPM_L1)
+		return 0;
+
+	if (dw_pcie_get_ltssm(pci) <= DW_PCIE_LTSSM_DETECT_ACT)
+		return 0;
+
+	if (!pci->pp.ops->pme_turn_off)
+		return 0;
+
+	pci->pp.ops->pme_turn_off(&pci->pp);
+
+	ret = read_poll_timeout(dw_pcie_get_ltssm, val, val == DW_PCIE_LTSSM_L2_IDLE,
+				PCIE_PME_TO_L2_TIMEOUT_US/10,
+				PCIE_PME_TO_L2_TIMEOUT_US, false, pci);
+	if (ret) {
+		dev_err(pci->dev, "Timeout waiting for L2 entry! LTSSM: 0x%x\n", val);
+		return ret;
+	}
+
+	if (pci->pp.ops->host_deinit)
+		pci->pp.ops->host_deinit(&pci->pp);
+
+	pci->suspended = true;
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(dw_pcie_suspend_noirq);
+
+int dw_pcie_resume_noirq(struct dw_pcie *pci)
+{
+	int ret;
+
+	if (!pci->suspended)
+		return 0;
+
+	pci->suspended = false;
+
+	if (pci->pp.ops->host_init) {
+		ret = pci->pp.ops->host_init(&pci->pp);
+		if (ret) {
+			dev_err(pci->dev, "Host init failed: %d\n", ret);
+			return ret;
+		}
+	}
+
+	dw_pcie_setup_rc(&pci->pp);
+
+	ret = dw_pcie_start_link(pci);
+	if (ret)
+		return ret;
+
+	ret = dw_pcie_wait_for_link(pci);
+	if (ret)
+		return ret;
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(dw_pcie_resume_noirq);
diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
index 615660640801..91d13f9b21b1 100644
--- a/drivers/pci/controller/dwc/pcie-designware.h
+++ b/drivers/pci/controller/dwc/pcie-designware.h
@@ -288,10 +288,21 @@ enum dw_pcie_core_rst {
 	DW_PCIE_NUM_CORE_RSTS
 };
 
+enum dw_pcie_ltssm {
+	/* Need to align with PCIE_PORT_DEBUG0 bits 0:5 */
+	DW_PCIE_LTSSM_DETECT_QUIET = 0x0,
+	DW_PCIE_LTSSM_DETECT_ACT = 0x1,
+	DW_PCIE_LTSSM_L0 = 0x11,
+	DW_PCIE_LTSSM_L2_IDLE = 0x15,
+
+	DW_PCIE_LTSSM_UNKNOWN = 0xFFFFFFFF,
+};
+
 struct dw_pcie_host_ops {
 	int (*host_init)(struct dw_pcie_rp *pp);
 	void (*host_deinit)(struct dw_pcie_rp *pp);
 	int (*msi_host_init)(struct dw_pcie_rp *pp);
+	void (*pme_turn_off)(struct dw_pcie_rp *pp);
 };
 
 struct dw_pcie_rp {
@@ -364,6 +375,7 @@ struct dw_pcie_ops {
 	void    (*write_dbi2)(struct dw_pcie *pcie, void __iomem *base, u32 reg,
 			      size_t size, u32 val);
 	int	(*link_up)(struct dw_pcie *pcie);
+	enum dw_pcie_ltssm (*get_ltssm)(struct dw_pcie *pcie);
 	int	(*start_link)(struct dw_pcie *pcie);
 	void	(*stop_link)(struct dw_pcie *pcie);
 };
@@ -393,6 +405,7 @@ struct dw_pcie {
 	struct reset_control_bulk_data	app_rsts[DW_PCIE_NUM_APP_RSTS];
 	struct reset_control_bulk_data	core_rsts[DW_PCIE_NUM_CORE_RSTS];
 	struct gpio_desc		*pe_rst;
+	bool			suspended;
 };
 
 #define to_dw_pcie_from_pp(port) container_of((port), struct dw_pcie, pp)
@@ -431,6 +444,9 @@ int dw_pcie_edma_detect(struct dw_pcie *pci);
 void dw_pcie_edma_remove(struct dw_pcie *pci);
 void dw_pcie_print_link_status(struct dw_pcie *pci);
 
+int dw_pcie_suspend_noirq(struct dw_pcie *pci);
+int dw_pcie_resume_noirq(struct dw_pcie *pci);
+
 static inline void dw_pcie_writel_dbi(struct dw_pcie *pci, u32 reg, u32 val)
 {
 	dw_pcie_write_dbi(pci, reg, 0x4, val);
@@ -502,6 +518,18 @@ static inline void dw_pcie_stop_link(struct dw_pcie *pci)
 		pci->ops->stop_link(pci);
 }
 
+static inline enum dw_pcie_ltssm dw_pcie_get_ltssm(struct dw_pcie *pci)
+{
+	u32 val;
+
+	if (pci->ops && pci->ops->get_ltssm)
+		return pci->ops->get_ltssm(pci);
+
+	val = dw_pcie_readl_dbi(pci, PCIE_PORT_DEBUG0);
+
+	return (enum dw_pcie_ltssm)FIELD_GET(PORT_LOGIC_LTSSM_STATE_MASK, val);
+}
+
 #ifdef CONFIG_PCIE_DW_HOST
 irqreturn_t dw_handle_msi_irq(struct dw_pcie_rp *pp);
 int dw_pcie_setup_rc(struct dw_pcie_rp *pp);
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index a4c397434057..da8156663c82 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -13,6 +13,12 @@
 
 #define PCIE_LINK_RETRAIN_TIMEOUT_MS	1000
 
+/*
+ * PCIe r6.0, sec 5.3.3.2.1 <PME Synchronization>
+ * Recommends 1ms to 10ms timeout to check L2 ready.
+ */
+#define PCIE_PME_TO_L2_TIMEOUT_US	10000
+
 extern const unsigned char pcie_link_speed[];
 extern bool pci_early_dump;