[PATCH v11 14/14] PCI: imx6: Add iMX95 Endpoint (EP) support

[Frank Li]

Add iMX95 EP support and add 64bit address support. Internal bus bridge for
PCI support 64bit dma address in iMX95. Hence, call
dma_set_mask_and_coherent() to set 64 bit DMA mask.

Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
Signed-off-by: Frank Li <Frank.Li@xxxxxxx>
---

Notes:
    Change from v10 to v11
    - rebase to linux-pci/endpoint.
    - move dma_set_mask_and_coherent() to imx6_add_pcie_ep() according to Robin
    Murphy's suggestion.
    
    Change from v9 to v10
    - using if (device_property_match_string(dev, "reg-names", "dbi2")) instead of
    	if (imx6_pcie->drvdata->variant == IMX95_EP)
    - so other platform can stat use "dbi2" in dts.
    
    @Mani: I change to check device_property_match_string(), so I can update
    other platform dts file, It should be better than
    	imx6_pcie->drvdata->variant == IMX95_EP
    
    Change from v8 to v9
    - update fixme comments
    - update BAR1 comments
    - Add mani's review tag
    Change from v7 to v8
    - Update commit message
    - Using Fixme
    - Update clks_cnts by ARRAY_SIZE
    
    Change from v4 to v7
    - none
    Change from v3 to v4
    - change align to 4k for imx95
    Change from v1 to v3
    - new patches at v3

 drivers/pci/controller/dwc/pci-imx6.c | 47 +++++++++++++++++++++++++++
 1 file changed, 47 insertions(+)

diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
index b714edac6d566..9c2ad803e1dbd 100644
--- a/drivers/pci/controller/dwc/pci-imx6.c
+++ b/drivers/pci/controller/dwc/pci-imx6.c
@@ -75,6 +75,7 @@ enum imx6_pcie_variants {
 	IMX8MQ_EP,
 	IMX8MM_EP,
 	IMX8MP_EP,
+	IMX95_EP,
 };
 
 #define IMX6_PCIE_FLAG_IMX6_PHY			BIT(0)
@@ -84,6 +85,7 @@ enum imx6_pcie_variants {
 #define IMX6_PCIE_FLAG_HAS_APP_RESET		BIT(4)
 #define IMX6_PCIE_FLAG_HAS_PHY_RESET		BIT(5)
 #define IMX6_PCIE_FLAG_HAS_SERDES		BIT(6)
+#define IMX6_PCIE_FLAG_SUPPORT_64BIT		BIT(7)
 
 #define imx6_check_flag(pci, val)     (pci->drvdata->flags & val)
 
@@ -616,6 +618,7 @@ static int imx6_pcie_enable_ref_clk(struct imx6_pcie *imx6_pcie)
 		break;
 	case IMX7D:
 	case IMX95:
+	case IMX95_EP:
 		break;
 	case IMX8MM:
 	case IMX8MM_EP:
@@ -1051,6 +1054,23 @@ static const struct pci_epc_features imx8m_pcie_epc_features = {
 	.align = SZ_64K,
 };
 
+/*
+ * BAR#	| Default BAR enable	| Default BAR Type	| Default BAR Size	| BAR Sizing Scheme
+ * ================================================================================================
+ * BAR0	| Enable		| 64-bit		| 1 MB			| Programmable Size
+ * BAR1	| Disable		| 32-bit		| 64 KB			| Fixed Size
+ *        BAR1 should be disabled if BAR0 is 64bit.
+ * BAR2	| Enable		| 32-bit		| 1 MB			| Programmable Size
+ * BAR3	| Enable		| 32-bit		| 64 KB			| Programmable Size
+ * BAR4	| Enable		| 32-bit		| 1M			| Programmable Size
+ * BAR5	| Enable		| 32-bit		| 64 KB			| Programmable Size
+ */
+static const struct pci_epc_features imx95_pcie_epc_features = {
+	.msi_capable = true,
+	.bar[BAR_1] = { .type = BAR_FIXED, .fixed_size = SZ_64K, },
+	.align = SZ_4K,
+};
+
 static const struct pci_epc_features*
 imx6_pcie_ep_get_features(struct dw_pcie_ep *ep)
 {
@@ -1093,6 +1113,18 @@ static int imx6_add_pcie_ep(struct imx6_pcie *imx6_pcie,
 
 	pci->dbi_base2 = pci->dbi_base + pcie_dbi2_offset;
 
+	/*
+	 * FIXME: Ideally, dbi2 base address should come from DT. But since only IMX95 is defining
+	 * "dbi2" in DT, "dbi_base2" is set to NULL here for that platform alone so that the DWC
+	 * core code can fetch that from DT. But once all platform DTs were fixed, this and the
+	 * above "dbi_base2" setting should be removed.
+	 */
+	if (device_property_match_string(dev, "reg-names", "dbi2") >= 0)
+		pci->dbi_base2 = NULL;
+
+	if (imx6_check_flag(imx6_pcie, IMX6_PCIE_FLAG_SUPPORT_64BIT))
+		dma_set_mask_and_coherent(dev, DMA_BIT_MASK(64));
+
 	ret = dw_pcie_ep_init(ep);
 	if (ret) {
 		dev_err(dev, "failed to initialize endpoint\n");
@@ -1562,6 +1594,20 @@ static const struct imx6_pcie_drvdata drvdata[] = {
 		.mode_mask[0] = IMX6Q_GPR12_DEVICE_TYPE,
 		.epc_features = &imx8m_pcie_epc_features,
 	},
+	[IMX95_EP] = {
+		.variant = IMX95_EP,
+		.flags = IMX6_PCIE_FLAG_HAS_SERDES |
+			 IMX6_PCIE_FLAG_SUPPORT_64BIT,
+		.clk_names = imx8mq_clks,
+		.clks_cnt = ARRAY_SIZE(imx8mq_clks),
+		.ltssm_off = IMX95_PE0_GEN_CTRL_3,
+		.ltssm_mask = IMX95_PCIE_LTSSM_EN,
+		.mode_off[0]  = IMX95_PE0_GEN_CTRL_1,
+		.mode_mask[0] = IMX95_PCIE_DEVICE_TYPE,
+		.init_phy = imx95_pcie_init_phy,
+		.epc_features = &imx95_pcie_epc_features,
+		.mode = DW_PCIE_EP_TYPE,
+	},
 };
 
 static const struct of_device_id imx6_pcie_of_match[] = {
@@ -1576,6 +1622,7 @@ static const struct of_device_id imx6_pcie_of_match[] = {
 	{ .compatible = "fsl,imx8mq-pcie-ep", .data = &drvdata[IMX8MQ_EP], },
 	{ .compatible = "fsl,imx8mm-pcie-ep", .data = &drvdata[IMX8MM_EP], },
 	{ .compatible = "fsl,imx8mp-pcie-ep", .data = &drvdata[IMX8MP_EP], },
+	{ .compatible = "fsl,imx95-pcie-ep", .data = &drvdata[IMX95_EP], },
 	{},
 };
 
-- 
2.34.1