[PATCH v5 6/6] PCI: spacemit-k1: Add Spacemit K3 PCIe host controller support

[Inochi Amaoto <inochiama@gmail.com>]

The PCIe controller on Spacemit K3 is almost a standard Synopsys
DesignWare PCIe IP with extra link and reset control. Unlike
the PCIe controller on K1, this controller supports external MSI
interrupt controller and can use multiple PHYs at the same time.

Add driver to support PCIe controller on Spacemit K3 PCIe.

Signed-off-by: Inochi Amaoto <inochiama@gmail.com>
---
 drivers/pci/controller/dwc/Kconfig            |   4 +-
 drivers/pci/controller/dwc/pcie-spacemit-k1.c | 132 ++++++++++++++++++
 2 files changed, 134 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/controller/dwc/Kconfig b/drivers/pci/controller/dwc/Kconfig
index dcfbe7e229fd..f9c27165260e 100644
--- a/drivers/pci/controller/dwc/Kconfig
+++ b/drivers/pci/controller/dwc/Kconfig
@@ -443,7 +443,7 @@ config PCIE_SOPHGO_DW
 	  Sophgo SoCs.
 
 config PCIE_SPACEMIT_K1
-	tristate "SpacemiT K1 PCIe controller (host mode)"
+	tristate "SpacemiT PCIe controller (host mode)"
 	depends on ARCH_SPACEMIT || COMPILE_TEST
 	depends on HAS_IOMEM
 	select PCIE_DW_HOST
@@ -451,7 +451,7 @@ config PCIE_SPACEMIT_K1
 	default ARCH_SPACEMIT
 	help
 	  Enables support for the DesignWare based PCIe controller in
-	  the SpacemiT K1 SoC operating in host mode.  Three controllers
+	  the SpacemiT SoC operating in host mode. Three controllers
 	  are available on the K1 SoC; the first of these shares a PHY
 	  with a USB 3.0 host controller (one or the other can be used).
 
diff --git a/drivers/pci/controller/dwc/pcie-spacemit-k1.c b/drivers/pci/controller/dwc/pcie-spacemit-k1.c
index c610b367412a..5031b688fdab 100644
--- a/drivers/pci/controller/dwc/pcie-spacemit-k1.c
+++ b/drivers/pci/controller/dwc/pcie-spacemit-k1.c
@@ -28,8 +28,18 @@
 #define SMLH_LINK_UP			BIT(1)
 #define RDLH_LINK_UP			BIT(12)
 
+#define INTR_STATUS				0x0010
+
 #define INTR_ENABLE				0x0014
 #define MSI_CTRL_INT			BIT(11)
+#define RDLH_LINK_UP_INT		BIT(20)
+
+#define K3_PHY_AHB_IRQSTATUS_INTX		0x0008
+
+#define K3_ADDR_INTR_STATUS1			0x0018
+
+#define K3_CACHE_MSTR_AWCACHE_MODE	GENMASK(14, 11)
+#define K3_CACHE_MSTR_AWCACHE_BEHAVIOR	0xf
 
 /* Some controls require APMU regmap access */
 #define SYSCON_APMU			"spacemit,apmu"
@@ -44,6 +54,9 @@
 
 #define PCIE_CONTROL_LOGIC			0x0004
 #define PCIE_SOFT_RESET			BIT(0)
+#define PCIE_PERSTN_OE			BIT(24)
+#define PCIE_PERSTN_OUT			BIT(25)
+#define PCIE_IGNORE_PERSTN		BIT(31)
 
 struct k1_pcie;
 
@@ -303,6 +316,116 @@ static int k1_pcie_parse_port(struct k1_pcie *k1)
 	return ret;
 }
 
+static int k3_pcie_init(struct dw_pcie_rp *pp)
+{
+	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+	struct k1_pcie *k1 = to_k1_pcie(pci);
+	u32 reset_ctrl = k1->pmu_off + PCIE_CLK_RESET_CONTROL;
+	u32 val;
+	int ret;
+
+	regmap_clear_bits(k1->pmu, reset_ctrl, LTSSM_EN);
+
+	k1_pcie_toggle_soft_reset(k1);
+
+	/* K3: Set IGNORE_PERSTN and drive PERSTN_OE high (assert reset) */
+	regmap_update_bits(k1->pmu, k1->pmu_off + PCIE_CONTROL_LOGIC,
+			   PCIE_IGNORE_PERSTN | PCIE_PERSTN_OE | PCIE_PERSTN_OUT,
+			   PCIE_IGNORE_PERSTN | PCIE_PERSTN_OE);
+
+	ret = k1_pcie_enable_resources(k1);
+	if (ret)
+		goto failed_resources;
+
+	regmap_set_bits(k1->pmu, reset_ctrl, PCIE_AUX_PWR_DET);
+	regmap_clear_bits(k1->pmu, reset_ctrl, APP_HOLD_PHY_RST);
+
+	ret = phy_bulk_init(k1->phy_count, k1->phys);
+	if (ret)
+		goto failed_phy;
+
+	msleep(PCIE_T_PVPERL_MS);
+
+	regmap_set_bits(k1->pmu, k1->pmu_off + PCIE_CONTROL_LOGIC,
+			PCIE_PERSTN_OUT | PCIE_PERSTN_OE);
+
+	val = dw_pcie_readl_dbi(pci, GEN3_EQ_CONTROL_OFF);
+	val = u32_replace_bits(val, BIT(7),
+			       GEN3_EQ_CONTROL_OFF_PSET_REQ_VEC);
+	dw_pcie_writel_dbi(pci, GEN3_EQ_CONTROL_OFF, val);
+
+	k1_pcie_set_device_id(k1);
+
+	/* Finally, as a workaround, disable ASPM L1 */
+	k1_pcie_disable_aspm_l1(k1);
+
+	return 0;
+
+failed_phy:
+	k1_pcie_disable_resources(k1);
+failed_resources:
+	regmap_update_bits(k1->pmu, k1->pmu_off + PCIE_CONTROL_LOGIC,
+			   PCIE_PERSTN_OUT | PCIE_PERSTN_OE | PCIE_IGNORE_PERSTN,
+			   PCIE_PERSTN_OUT | PCIE_PERSTN_OE);
+
+	return ret;
+}
+
+static void k3_pcie_deinit(struct dw_pcie_rp *pp)
+{
+	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+	struct k1_pcie *k1 = to_k1_pcie(pci);
+
+	/* Assert fundamental reset (drive PERST# low) */
+	regmap_update_bits(k1->pmu, k1->pmu_off + PCIE_CONTROL_LOGIC,
+			   PCIE_PERSTN_OUT | PCIE_PERSTN_OE,
+			   PCIE_PERSTN_OE);
+
+	phy_bulk_exit(k1->phy_count, k1->phys);
+
+	k1_pcie_disable_resources(k1);
+}
+
+static int k3_pcie_msi_host_init(struct dw_pcie_rp *pp)
+{
+	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+	u32 val;
+
+	dw_pcie_dbi_ro_wr_en(pci);
+
+	/* For IMSIC interrupt */
+	val = dw_pcie_readl_dbi(pci, COHERENCY_CONTROL_3_OFF);
+	val = u32_replace_bits(val, K3_CACHE_MSTR_AWCACHE_BEHAVIOR,
+			       K3_CACHE_MSTR_AWCACHE_MODE);
+	dw_pcie_writel_dbi(pci, COHERENCY_CONTROL_3_OFF, val);
+
+	dw_pcie_dbi_ro_wr_dis(pci);
+
+	return 0;
+}
+
+static const struct dw_pcie_host_ops k3_pcie_host_ops = {
+	.init		= k3_pcie_init,
+	.deinit		= k3_pcie_deinit,
+	.msi_init	= k3_pcie_msi_host_init,
+};
+
+static int k3_pcie_parse_port(struct k1_pcie *k1)
+{
+	u32 status0, status1, status2;
+
+	/* This register require a RAW for cleanup */
+	status0 = readl_relaxed(k1->link + K3_PHY_AHB_IRQSTATUS_INTX);
+	status1 = readl_relaxed(k1->link + INTR_STATUS);
+	status2 = readl_relaxed(k1->link + K3_ADDR_INTR_STATUS1);
+
+	writel_relaxed(status0, k1->link + K3_PHY_AHB_IRQSTATUS_INTX);
+	writel_relaxed(status1, k1->link + INTR_STATUS);
+	writel_relaxed(status2, k1->link + K3_ADDR_INTR_STATUS1);
+
+	return k1_pcie_parse_port(k1);
+}
+
 static int k1_pcie_probe(struct platform_device *pdev)
 {
 	const struct k1_pcie_device_data *data;
@@ -380,8 +503,17 @@ static const struct k1_pcie_device_data k1_pcie_device_data = {
 	.device_id	= PCI_DEVICE_ID_SPACEMIT_K1,
 };
 
+static const struct k1_pcie_device_data k3_pcie_device_data = {
+	.host_ops	= &k3_pcie_host_ops,
+	.ops		= &k1_pcie_ops,
+	.parse_port	= k3_pcie_parse_port,
+	.max_phy_count	= 6,
+	.device_id	= PCI_DEVICE_ID_SPACEMIT_K3,
+};
+
 static const struct of_device_id k1_pcie_of_match_table[] = {
 	{ .compatible = "spacemit,k1-pcie", .data = &k1_pcie_device_data },
+	{ .compatible = "spacemit,k3-pcie", .data = &k3_pcie_device_data },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, k1_pcie_of_match_table);
-- 
2.55.0