Merge branch 'pci/controller/layerscape'

- Add suspend/resume support for Layerscape LS1043a, including
  software-managed PME_Turn_Off and transitions between L0, L2/L3_Ready
  Link states (Frank Li)

* pci/controller/layerscape:
  PCI: layerscape: Add suspend/resume for ls1043a
  PCI: layerscape(ep): Rename pf_* as pf_lut_*
  PCI: layerscape: Add suspend/resume for ls1021a
  PCI: layerscape: Add function pointer for exit_from_l2()

Author: bjorn-helgaas

drivers/pci/controller/dwc/pci-layerscape-ep.c

@@ -49,7 +49,7 @@ struct ls_pcie_ep {
 	bool				big_endian;
 };
 
-static u32 ls_lut_readl(struct ls_pcie_ep *pcie, u32 offset)
+static u32 ls_pcie_pf_lut_readl(struct ls_pcie_ep *pcie, u32 offset)
 {
 	struct dw_pcie *pci = pcie->pci;
 
@@ -59,7 +59,7 @@ static u32 ls_lut_readl(struct ls_pcie_ep *pcie, u32 offset)
 		return ioread32(pci->dbi_base + offset);
 }
 
-static void ls_lut_writel(struct ls_pcie_ep *pcie, u32 offset, u32 value)
+static void ls_pcie_pf_lut_writel(struct ls_pcie_ep *pcie, u32 offset, u32 value)
 {
 	struct dw_pcie *pci = pcie->pci;
 
@@ -76,8 +76,8 @@ static irqreturn_t ls_pcie_ep_event_handler(int irq, void *dev_id)
 	u32 val, cfg;
 	u8 offset;
 
-	val = ls_lut_readl(pcie, PEX_PF0_PME_MES_DR);
-	ls_lut_writel(pcie, PEX_PF0_PME_MES_DR, val);
+	val = ls_pcie_pf_lut_readl(pcie, PEX_PF0_PME_MES_DR);
+	ls_pcie_pf_lut_writel(pcie, PEX_PF0_PME_MES_DR, val);
 
 	if (!val)
 		return IRQ_NONE;
@@ -96,9 +96,9 @@ static irqreturn_t ls_pcie_ep_event_handler(int irq, void *dev_id)
 		dw_pcie_writel_dbi(pci, offset + PCI_EXP_LNKCAP, pcie->lnkcap);
 		dw_pcie_dbi_ro_wr_dis(pci);
 
-		cfg = ls_lut_readl(pcie, PEX_PF0_CONFIG);
+		cfg = ls_pcie_pf_lut_readl(pcie, PEX_PF0_CONFIG);
 		cfg |= PEX_PF0_CFG_READY;
-		ls_lut_writel(pcie, PEX_PF0_CONFIG, cfg);
+		ls_pcie_pf_lut_writel(pcie, PEX_PF0_CONFIG, cfg);
 		dw_pcie_ep_linkup(&pci->ep);
 
 		dev_dbg(pci->dev, "Link up\n");
@@ -130,10 +130,10 @@ static int ls_pcie_ep_interrupt_init(struct ls_pcie_ep *pcie,
 	}
 
 	/* Enable interrupts */
-	val = ls_lut_readl(pcie, PEX_PF0_PME_MES_IER);
+	val = ls_pcie_pf_lut_readl(pcie, PEX_PF0_PME_MES_IER);
 	val |=  PEX_PF0_PME_MES_IER_LDDIE | PEX_PF0_PME_MES_IER_HRDIE |
 		PEX_PF0_PME_MES_IER_LUDIE;
-	ls_lut_writel(pcie, PEX_PF0_PME_MES_IER, val);
+	ls_pcie_pf_lut_writel(pcie, PEX_PF0_PME_MES_IER, val);
 
 	return 0;
 }

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

@@ -35,21 +35,41 @@
 #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
 
 struct ls_pcie_drvdata {
-	const u32 pf_off;
+	const u32 pf_lut_off;
+	const struct dw_pcie_host_ops *ops;
+	int (*exit_from_l2)(struct dw_pcie_rp *pp);
+	bool scfg_support;
 	bool pm_support;
 };
 
 struct ls_pcie {
 	struct dw_pcie *pci;
 	const struct ls_pcie_drvdata *drvdata;
-	void __iomem *pf_base;
+	void __iomem *pf_lut_base;
+	struct regmap *scfg;
+	int index;
 	bool big_endian;
 };
 
-#define ls_pcie_pf_readl_addr(addr)	ls_pcie_pf_readl(pcie, addr)
+#define ls_pcie_pf_lut_readl_addr(addr)	ls_pcie_pf_lut_readl(pcie, addr)
 #define to_ls_pcie(x)	dev_get_drvdata((x)->dev)
 
 static bool ls_pcie_is_bridge(struct ls_pcie *pcie)
@@ -90,20 +110,20 @@ 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)
+static u32 ls_pcie_pf_lut_readl(struct ls_pcie *pcie, u32 off)
 {
 	if (pcie->big_endian)
-		return ioread32be(pcie->pf_base + off);
+		return ioread32be(pcie->pf_lut_base + off);
 
-	return ioread32(pcie->pf_base + off);
+	return ioread32(pcie->pf_lut_base + off);
 }
 
-static void ls_pcie_pf_writel(struct ls_pcie *pcie, u32 off, u32 val)
+static void ls_pcie_pf_lut_writel(struct ls_pcie *pcie, u32 off, u32 val)
 {
 	if (pcie->big_endian)
-		iowrite32be(val, pcie->pf_base + off);
+		iowrite32be(val, pcie->pf_lut_base + off);
 	else
-		iowrite32(val, pcie->pf_base + off);
+		iowrite32(val, pcie->pf_lut_base + off);
 }
 
 static void ls_pcie_send_turnoff_msg(struct dw_pcie_rp *pp)
@@ -113,19 +133,19 @@ static void ls_pcie_send_turnoff_msg(struct dw_pcie_rp *pp)
 	u32 val;
 	int ret;
 
-	val = ls_pcie_pf_readl(pcie, LS_PCIE_PF_MCR);
+	val = ls_pcie_pf_lut_readl(pcie, LS_PCIE_PF_MCR);
 	val |= PF_MCR_PTOMR;
-	ls_pcie_pf_writel(pcie, LS_PCIE_PF_MCR, val);
+	ls_pcie_pf_lut_writel(pcie, LS_PCIE_PF_MCR, val);
 
-	ret = readx_poll_timeout(ls_pcie_pf_readl_addr, LS_PCIE_PF_MCR,
+	ret = readx_poll_timeout(ls_pcie_pf_lut_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)
+static int 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);
@@ -136,20 +156,22 @@ static void ls_pcie_exit_from_l2(struct dw_pcie_rp *pp)
 	 * 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 = ls_pcie_pf_lut_readl(pcie, LS_PCIE_PF_MCR);
 	val |= PF_MCR_EXL2S;
-	ls_pcie_pf_writel(pcie, LS_PCIE_PF_MCR, val);
+	ls_pcie_pf_lut_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,
+	ret = readx_poll_timeout(ls_pcie_pf_lut_readl_addr, LS_PCIE_PF_MCR,
 				 val, !(val & PF_MCR_EXL2S),
 				 1000,
 				 10000);
 	if (ret)
 		dev_err(pcie->pci->dev, "L2 exit timeout\n");
+
+	return ret;
 }
 
 static int ls_pcie_host_init(struct dw_pcie_rp *pp)
@@ -168,25 +190,130 @@ static int ls_pcie_host_init(struct dw_pcie_rp *pp)
 	return 0;
 }
 
+static void scfg_pcie_send_turnoff_msg(struct regmap *scfg, u32 reg, u32 mask)
+{
+	/* Send PME_Turn_Off message */
+	regmap_write_bits(scfg, reg, mask, mask);
+
+	/*
+	 * There is no specific register to check for PME_To_Ack from endpoint.
+	 * So on the safe side, wait for PCIE_PME_TO_L2_TIMEOUT_US.
+	 */
+	mdelay(PCIE_PME_TO_L2_TIMEOUT_US/1000);
+
+	/*
+	 * Layerscape hardware reference manual recommends clearing the PMXMTTURNOFF bit
+	 * to complete the PME_Turn_Off handshake.
+	 */
+	regmap_write_bits(scfg, reg, mask, 0);
+}
+
+static void ls1021a_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);
+
+	scfg_pcie_send_turnoff_msg(pcie->scfg, SCFG_PEXPMWRCR(pcie->index), PMXMTTURNOFF);
+}
+
+static int scfg_pcie_exit_from_l2(struct regmap *scfg, u32 reg, u32 mask)
+{
+	/* Reset the PEX wrapper to bring the link out of L2 */
+	regmap_write_bits(scfg, reg, mask, mask);
+	regmap_write_bits(scfg, reg, mask, 0);
+
+	return 0;
+}
+
+static int ls1021a_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);
+
+	return scfg_pcie_exit_from_l2(pcie->scfg, SCFG_PEXSFTRSTCR, PEXSR(pcie->index));
+}
+
+static void ls1043a_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);
+
+	scfg_pcie_send_turnoff_msg(pcie->scfg, SCFG_PEXPMECR, PEXPME(pcie->index));
+}
+
+static int ls1043a_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;
+
+	/*
+	 * Reset the PEX wrapper to bring the link out of L2.
+	 * LDBG_WE: allows the user to have write access to the PEXDBG[SR] for both setting and
+	 *	    clearing the soft reset on the PEX module.
+	 * LDBG_SR: When SR is set to 1, the PEX module enters soft reset.
+	 */
+	val = ls_pcie_pf_lut_readl(pcie, LS_PCIE_LDBG);
+	val |= LDBG_WE;
+	ls_pcie_pf_lut_writel(pcie, LS_PCIE_LDBG, val);
+
+	val = ls_pcie_pf_lut_readl(pcie, LS_PCIE_LDBG);
+	val |= LDBG_SR;
+	ls_pcie_pf_lut_writel(pcie, LS_PCIE_LDBG, val);
+
+	val = ls_pcie_pf_lut_readl(pcie, LS_PCIE_LDBG);
+	val &= ~LDBG_SR;
+	ls_pcie_pf_lut_writel(pcie, LS_PCIE_LDBG, val);
+
+	val = ls_pcie_pf_lut_readl(pcie, LS_PCIE_LDBG);
+	val &= ~LDBG_WE;
+	ls_pcie_pf_lut_writel(pcie, LS_PCIE_LDBG, val);
+
+	return 0;
+}
+
 static const struct dw_pcie_host_ops ls_pcie_host_ops = {
 	.init = ls_pcie_host_init,
 	.pme_turn_off = ls_pcie_send_turnoff_msg,
 };
 
+static const struct dw_pcie_host_ops ls1021a_pcie_host_ops = {
+	.init = ls_pcie_host_init,
+	.pme_turn_off = ls1021a_pcie_send_turnoff_msg,
+};
+
 static const struct ls_pcie_drvdata ls1021a_drvdata = {
-	.pm_support = false,
+	.pm_support = true,
+	.scfg_support = true,
+	.ops = &ls1021a_pcie_host_ops,
+	.exit_from_l2 = ls1021a_pcie_exit_from_l2,
+};
+
+static const struct dw_pcie_host_ops ls1043a_pcie_host_ops = {
+	.init = ls_pcie_host_init,
+	.pme_turn_off = ls1043a_pcie_send_turnoff_msg,
+};
+
+static const struct ls_pcie_drvdata ls1043a_drvdata = {
+	.pf_lut_off = 0x10000,
+	.pm_support = true,
+	.scfg_support = true,
+	.ops = &ls1043a_pcie_host_ops,
+	.exit_from_l2 = ls1043a_pcie_exit_from_l2,
 };
 
 static const struct ls_pcie_drvdata layerscape_drvdata = {
-	.pf_off = 0xc0000,
+	.pf_lut_off = 0xc0000,
 	.pm_support = true,
+	.ops = &ls_pcie_host_ops,
+	.exit_from_l2 = ls_pcie_exit_from_l2,
 };
 
 static const struct of_device_id ls_pcie_of_match[] = {
 	{ .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,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 },
@@ -201,6 +328,8 @@ static int ls_pcie_probe(struct platform_device *pdev)
 	struct dw_pcie *pci;
 	struct ls_pcie *pcie;
 	struct resource *dbi_base;
+	u32 index[2];
+	int ret;
 
 	pcie = devm_kzalloc(dev, sizeof(*pcie), GFP_KERNEL);
 	if (!pcie)
@@ -213,9 +342,8 @@ static int ls_pcie_probe(struct platform_device *pdev)
 	pcie->drvdata = of_device_get_match_data(dev);
 
 	pci->dev = dev;
-	pci->pp.ops = &ls_pcie_host_ops;
-
 	pcie->pci = pci;
+	pci->pp.ops = pcie->drvdata->ops;
 
 	dbi_base = platform_get_resource_byname(pdev, IORESOURCE_MEM, "regs");
 	pci->dbi_base = devm_pci_remap_cfg_resource(dev, dbi_base);
@@ -224,7 +352,21 @@ static int ls_pcie_probe(struct platform_device *pdev)
 
 	pcie->big_endian = of_property_read_bool(dev->of_node, "big-endian");
 
-	pcie->pf_base = pci->dbi_base + pcie->drvdata->pf_off;
+	pcie->pf_lut_base = pci->dbi_base + pcie->drvdata->pf_lut_off;
+
+	if (pcie->drvdata->scfg_support) {
+		pcie->scfg = syscon_regmap_lookup_by_phandle(dev->of_node, "fsl,pcie-scfg");
+		if (IS_ERR(pcie->scfg)) {
+			dev_err(dev, "No syscfg phandle specified\n");
+			return PTR_ERR(pcie->scfg);
+		}
+
+		ret = of_property_read_u32_array(dev->of_node, "fsl,pcie-scfg", index, 2);
+		if (ret)
+			return ret;
+
+		pcie->index = index[1];
+	}
 
 	if (!ls_pcie_is_bridge(pcie))
 		return -ENODEV;
@@ -247,11 +389,14 @@ static int ls_pcie_suspend_noirq(struct device *dev)
 static int ls_pcie_resume_noirq(struct device *dev)
 {
 	struct ls_pcie *pcie = dev_get_drvdata(dev);
+	int ret;
 
 	if (!pcie->drvdata->pm_support)
 		return 0;
 
-	ls_pcie_exit_from_l2(&pcie->pci->pp);
+	ret = pcie->drvdata->exit_from_l2(&pcie->pci->pp);
+	if (ret)
+		return ret;
 
 	return dw_pcie_resume_noirq(pcie->pci);
 }