[PATCH 6/6] PCI: dwc: Add common send pme_turn_off message method

[Frank Li]

Set outbound ATU map memory write to send PCI message. So one MMIO write
can trigger a PCI message, such as pme_turn_off.

Add common dw_pcie_send_pme_turn_off_by_atu() function.

Call dw_pcie_send_pme_turn_off_by_atu() to send out pme_turn_off message in
general dw_pcie_suspend_noirq() if there are not platform callback
pme_turn_off() exist.

Signed-off-by: Frank Li <Frank.Li@xxxxxxx>
---
 drivers/pci/controller/dwc/pcie-designware-host.c | 51 +++++++++++++++++++++--
 drivers/pci/controller/dwc/pcie-designware.c      |  8 ++++
 drivers/pci/controller/dwc/pcie-designware.h      |  3 ++
 3 files changed, 58 insertions(+), 4 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
index 267687ab33cbc..2a281060f3aad 100644
--- a/drivers/pci/controller/dwc/pcie-designware-host.c
+++ b/drivers/pci/controller/dwc/pcie-designware-host.c
@@ -728,6 +728,8 @@ static int dw_pcie_iatu_setup(struct dw_pcie_rp *pp)
 		dev_warn(pci->dev, "Ranges exceed outbound iATU size (%d)\n",
 			 pci->num_ob_windows);
 
+	pci->msg_atu_index = i;
+
 	i = 0;
 	resource_list_for_each_entry(entry, &pp->bridge->dma_ranges) {
 		if (resource_type(entry->res) != IORESOURCE_MEM)
@@ -833,11 +835,49 @@ int dw_pcie_setup_rc(struct dw_pcie_rp *pp)
 }
 EXPORT_SYMBOL_GPL(dw_pcie_setup_rc);
 
+static int dw_pcie_send_pme_turn_off_by_atu(struct dw_pcie *pci)
+{
+	struct dw_pcie_ob_atu_cfg atu = { 0 };
+	void __iomem *m;
+	int ret = 0;
+
+	if (pci->num_ob_windows <= pci->msg_atu_index)
+		return -EINVAL;
+
+	atu.code = PCI_MSG_CODE_PME_TURN_OFF;
+	atu.routing = PCI_MSG_TYPE_R_BC;
+	atu.type = PCIE_ATU_TYPE_MSG;
+	atu.size = pci->msg_io_size;
+
+	if (!atu.size) {
+		dev_dbg(pci->dev,
+			"atu memory map windows is zero, please check 'msg' reg in dts\n");
+		return -ENOMEM;
+	}
+
+	atu.cpu_addr = pci->msg_io_base;
+
+	ret = dw_pcie_prog_outbound_atu(pci, &atu);
+	if (ret)
+		return ret;
+
+	m = ioremap(atu.cpu_addr, PAGE_SIZE);
+	if (!m)
+		return -ENOMEM;
+
+	/* A dummy write is converted to a Msg TLP */
+	writel(0, m);
+
+	iounmap(m);
+
+	return ret;
+}
+
 int dw_pcie_suspend_noirq(struct dw_pcie *pci)
 {
 	u8 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
 	u32 val;
-	int ret;
+	int ret = 0;
 
 	/*
 	 * If L1SS is supported, then do not put the link into L2 as some
@@ -849,10 +889,13 @@ int dw_pcie_suspend_noirq(struct dw_pcie *pci)
 	if (dw_pcie_get_ltssm(pci) <= DW_PCIE_LTSSM_DETECT_ACT)
 		return 0;
 
-	if (!pci->pp.ops->pme_turn_off)
-		return 0;
+	if (pci->pp.ops->pme_turn_off)
+		pci->pp.ops->pme_turn_off(&pci->pp);
+	else
+		ret = dw_pcie_send_pme_turn_off_by_atu(pci);
 
-	pci->pp.ops->pme_turn_off(&pci->pp);
+	if (ret)
+		return ret;
 
 	ret = read_poll_timeout(dw_pcie_get_ltssm, val, val == DW_PCIE_LTSSM_L2_IDLE,
 				PCIE_PME_TO_L2_TIMEOUT_US/10,
diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c
index ba909fade9db1..eb24362009bb6 100644
--- a/drivers/pci/controller/dwc/pcie-designware.c
+++ b/drivers/pci/controller/dwc/pcie-designware.c
@@ -155,6 +155,14 @@ int dw_pcie_get_resources(struct dw_pcie *pci)
 		}
 	}
 
+	if (!pci->msg_io_base) {
+		res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "msg");
+		if (res) {
+			pci->msg_io_base = res->start;
+			pci->msg_io_size = res->end - res->start + 1;
+		}
+	}
+
 	/* LLDD is supposed to manually switch the clocks and resets state */
 	if (dw_pcie_cap_is(pci, REQ_RES)) {
 		ret = dw_pcie_get_clocks(pci);
diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
index 703b50bc5e0f1..866ab44df9fd1 100644
--- a/drivers/pci/controller/dwc/pcie-designware.h
+++ b/drivers/pci/controller/dwc/pcie-designware.h
@@ -424,6 +424,9 @@ struct dw_pcie {
 	struct reset_control_bulk_data	core_rsts[DW_PCIE_NUM_CORE_RSTS];
 	struct gpio_desc		*pe_rst;
 	bool			suspended;
+	int			msg_atu_index;
+	phys_addr_t		msg_io_base;
+	size_t			msg_io_size;
 };
 
 #define to_dw_pcie_from_pp(port) container_of((port), struct dw_pcie, pp)

-- 
2.34.1