PCI: j721e: Add per platform maximum lane settings

Various platforms have different maximum amount of lanes that can be
selected. Add max_lanes to struct j721e_pcie to allow for detection of this
which is needed to calculate the needed bitmask size for the possible lane
count.

Link: https://lore.kernel.org/linux-pci/[email protected]
Signed-off-by: Matt Ranostay <[email protected]>
Signed-off-by: Achal Verma <[email protected]>
Signed-off-by: Siddharth Vadapalli <[email protected]>
Signed-off-by: Krzysztof Wilczyński <[email protected]>
Reviewed-by: Ravi Gunasekaran <[email protected]>

Author: mranostay

drivers/pci/controller/cadence/pci-j721e.c

@@ -47,8 +47,6 @@ enum link_status {
 
 #define GENERATION_SEL_MASK		GENMASK(1, 0)
 
-#define MAX_LANES			2
-
 struct j721e_pcie {
 	struct cdns_pcie	*cdns_pcie;
 	struct clk		*refclk;
@@ -71,6 +69,7 @@ struct j721e_pcie_data {
 	unsigned int		quirk_disable_flr:1;
 	u32			linkdown_irq_regfield;
 	unsigned int		byte_access_allowed:1;
+	unsigned int		max_lanes;
 };
 
 static inline u32 j721e_pcie_user_readl(struct j721e_pcie *pcie, u32 offset)
@@ -290,35 +289,41 @@ static const struct j721e_pcie_data j721e_pcie_rc_data = {
 	.quirk_retrain_flag = true,
 	.byte_access_allowed = false,
 	.linkdown_irq_regfield = LINK_DOWN,
+	.max_lanes = 2,
 };
 
 static const struct j721e_pcie_data j721e_pcie_ep_data = {
 	.mode = PCI_MODE_EP,
 	.linkdown_irq_regfield = LINK_DOWN,
+	.max_lanes = 2,
 };
 
 static const struct j721e_pcie_data j7200_pcie_rc_data = {
 	.mode = PCI_MODE_RC,
 	.quirk_detect_quiet_flag = true,
 	.linkdown_irq_regfield = J7200_LINK_DOWN,
 	.byte_access_allowed = true,
+	.max_lanes = 2,
 };
 
 static const struct j721e_pcie_data j7200_pcie_ep_data = {
 	.mode = PCI_MODE_EP,
 	.quirk_detect_quiet_flag = true,
 	.quirk_disable_flr = true,
+	.max_lanes = 2,
 };
 
 static const struct j721e_pcie_data am64_pcie_rc_data = {
 	.mode = PCI_MODE_RC,
 	.linkdown_irq_regfield = J7200_LINK_DOWN,
 	.byte_access_allowed = true,
+	.max_lanes = 1,
 };
 
 static const struct j721e_pcie_data am64_pcie_ep_data = {
 	.mode = PCI_MODE_EP,
 	.linkdown_irq_regfield = J7200_LINK_DOWN,
+	.max_lanes = 1,
 };
 
 static const struct of_device_id of_j721e_pcie_match[] = {
@@ -432,8 +437,10 @@ static int j721e_pcie_probe(struct platform_device *pdev)
 	pcie->user_cfg_base = base;
 
 	ret = of_property_read_u32(node, "num-lanes", &num_lanes);
-	if (ret || num_lanes > MAX_LANES)
+	if (ret || num_lanes > data->max_lanes) {
+		dev_warn(dev, "num-lanes property not provided or invalid, setting num-lanes to 1\n");
 		num_lanes = 1;
+	}
 	pcie->num_lanes = num_lanes;
 
 	if (dma_set_mask_and_coherent(dev, DMA_BIT_MASK(48)))