[PATCH v6 3/3] PCI: cadence: Add LGA IP debugfs for LTSSM status
From: Hans Zhang
Date: Tue May 19 2026 - 08:41:15 EST
Extend debugfs support to LGA-based Cadence PCIe controllers. The
'ltssm_status' file now works for both HPA and LGA IP by selecting the
appropriate register access based on the 'is_hpa' flag.
Signed-off-by: Hans Zhang <18255117159@xxxxxxx>
---
.../controller/cadence/pcie-cadence-debugfs.c | 61 ++++++++++++++++++-
.../pci/controller/cadence/pcie-cadence-ep.c | 3 +
.../controller/cadence/pcie-cadence-host.c | 9 ++-
drivers/pci/controller/cadence/pcie-cadence.h | 43 +++++++++++++
4 files changed, 112 insertions(+), 4 deletions(-)
diff --git a/drivers/pci/controller/cadence/pcie-cadence-debugfs.c b/drivers/pci/controller/cadence/pcie-cadence-debugfs.c
index 97c5deef2b1a..0a308f95e9f6 100644
--- a/drivers/pci/controller/cadence/pcie-cadence-debugfs.c
+++ b/drivers/pci/controller/cadence/pcie-cadence-debugfs.c
@@ -13,6 +13,58 @@
#define CDNS_DEBUGFS_BUF_MAX 128
+static const char *cdns_pcie_lga_ltssm_status_string(enum cdns_pcie_lga_ltssm ltssm)
+{
+ const char *str;
+
+ switch (ltssm) {
+#define CDNS_PCIE_LGA_LTSSM_NAME(n) case n: str = #n; break
+ CDNS_PCIE_LGA_LTSSM_NAME(CDNS_PCIE_LGA_LTSSM_DETECT_QUIET);
+ CDNS_PCIE_LGA_LTSSM_NAME(CDNS_PCIE_LGA_LTSSM_DETECT_ACTIVE);
+ CDNS_PCIE_LGA_LTSSM_NAME(CDNS_PCIE_LGA_LTSSM_POLLING_ACTIVE);
+ CDNS_PCIE_LGA_LTSSM_NAME(CDNS_PCIE_LGA_LTSSM_POLLING_COMPLIANCE);
+ CDNS_PCIE_LGA_LTSSM_NAME(CDNS_PCIE_LGA_LTSSM_POLLING_CONFIGURATION);
+ CDNS_PCIE_LGA_LTSSM_NAME(CDNS_PCIE_LGA_LTSSM_CONFIGURATION_LINKWIDTH_START);
+ CDNS_PCIE_LGA_LTSSM_NAME(CDNS_PCIE_LGA_LTSSM_CONFIGURATION_LINKWIDTH_ACCEPT);
+ CDNS_PCIE_LGA_LTSSM_NAME(CDNS_PCIE_LGA_LTSSM_CONFIGURATION_LANENUM_ACCEPT);
+ CDNS_PCIE_LGA_LTSSM_NAME(CDNS_PCIE_LGA_LTSSM_CONFIGURATION_LANENUM_WAIT);
+ CDNS_PCIE_LGA_LTSSM_NAME(CDNS_PCIE_LGA_LTSSM_CONFIGURATION_COMPLETE);
+ CDNS_PCIE_LGA_LTSSM_NAME(CDNS_PCIE_LGA_LTSSM_CONFIGURATION_IDLE);
+ CDNS_PCIE_LGA_LTSSM_NAME(CDNS_PCIE_LGA_LTSSM_RECOVERY_RCVRLOCK);
+ CDNS_PCIE_LGA_LTSSM_NAME(CDNS_PCIE_LGA_LTSSM_RECOVERY_SPEED);
+ CDNS_PCIE_LGA_LTSSM_NAME(CDNS_PCIE_LGA_LTSSM_RECOVERY_RCVRCFG);
+ CDNS_PCIE_LGA_LTSSM_NAME(CDNS_PCIE_LGA_LTSSM_RECOVERY_IDLE);
+ CDNS_PCIE_LGA_LTSSM_NAME(CDNS_PCIE_LGA_LTSSM_L0);
+ CDNS_PCIE_LGA_LTSSM_NAME(CDNS_PCIE_LGA_LTSSM_RX_L0S_ENTRY);
+ CDNS_PCIE_LGA_LTSSM_NAME(CDNS_PCIE_LGA_LTSSM_RX_L0S_IDLE);
+ CDNS_PCIE_LGA_LTSSM_NAME(CDNS_PCIE_LGA_LTSSM_RX_L0S_FTS);
+ CDNS_PCIE_LGA_LTSSM_NAME(CDNS_PCIE_LGA_LTSSM_TX_L0S_ENTRY);
+ CDNS_PCIE_LGA_LTSSM_NAME(CDNS_PCIE_LGA_LTSSM_TX_L0S_IDLE);
+ CDNS_PCIE_LGA_LTSSM_NAME(CDNS_PCIE_LGA_LTSSM_TX_L0S_FTS);
+ CDNS_PCIE_LGA_LTSSM_NAME(CDNS_PCIE_LGA_LTSSM_L1_ENTRY);
+ CDNS_PCIE_LGA_LTSSM_NAME(CDNS_PCIE_LGA_LTSSM_L1_IDLE);
+ CDNS_PCIE_LGA_LTSSM_NAME(CDNS_PCIE_LGA_LTSSM_L2_IDLE);
+ CDNS_PCIE_LGA_LTSSM_NAME(CDNS_PCIE_LGA_LTSSM_L2_TRANSMITWAKE);
+ CDNS_PCIE_LGA_LTSSM_NAME(CDNS_PCIE_LGA_LTSSM_DISABLED);
+ CDNS_PCIE_LGA_LTSSM_NAME(CDNS_PCIE_LGA_LTSSM_LOOPBACK_ENTRY_MASTER);
+ CDNS_PCIE_LGA_LTSSM_NAME(CDNS_PCIE_LGA_LTSSM_LOOPBACK_ACTIVE_MASTER);
+ CDNS_PCIE_LGA_LTSSM_NAME(CDNS_PCIE_LGA_LTSSM_LOOPBACK_EXIT_MASTER);
+ CDNS_PCIE_LGA_LTSSM_NAME(CDNS_PCIE_LGA_LTSSM_LOOPBACK_ENTRY_SLAVE);
+ CDNS_PCIE_LGA_LTSSM_NAME(CDNS_PCIE_LGA_LTSSM_LOOPBACK_ACTIVE_SLAVE);
+ CDNS_PCIE_LGA_LTSSM_NAME(CDNS_PCIE_LGA_LTSSM_LOOPBACK_EXIT_SLAVE);
+ CDNS_PCIE_LGA_LTSSM_NAME(CDNS_PCIE_LGA_LTSSM_HOT_RESET);
+ CDNS_PCIE_LGA_LTSSM_NAME(CDNS_PCIE_LGA_LTSSM_RECOVERY_EQUALIZATION_PHASE_0);
+ CDNS_PCIE_LGA_LTSSM_NAME(CDNS_PCIE_LGA_LTSSM_RECOVERY_EQUALIZATION_PHASE_1);
+ CDNS_PCIE_LGA_LTSSM_NAME(CDNS_PCIE_LGA_LTSSM_RECOVERY_EQUALIZATION_PHASE_2);
+ CDNS_PCIE_LGA_LTSSM_NAME(CDNS_PCIE_LGA_LTSSM_RECOVERY_EQUALIZATION_PHASE_3);
+ default:
+ str = "CDNS_PCIE_LGA_LTSSM_UNKNOWN";
+ break;
+ }
+
+ return str + strlen("CDNS_PCIE_LGA_LTSSM_");
+}
+
static const char *cdns_pcie_hpa_ltssm_status_string(enum cdns_pcie_hpa_ltssm ltssm)
{
const char *str;
@@ -158,6 +210,7 @@ static const char *cdns_pcie_hpa_ltssm_status_string(enum cdns_pcie_hpa_ltssm lt
static int ltssm_status_show(struct seq_file *s, void *v)
{
struct cdns_pcie *pci = s->private;
+ enum cdns_pcie_lga_ltssm lga_ltssm;
enum cdns_pcie_hpa_ltssm hpa_ltssm;
const char *str_ltssm;
u32 val;
@@ -168,11 +221,13 @@ static int ltssm_status_show(struct seq_file *s, void *v)
hpa_ltssm = FIELD_GET(CDNS_PCIE_HPA_LTSSM_STATUS_MASK, val);
str_ltssm = cdns_pcie_hpa_ltssm_status_string(hpa_ltssm);
} else {
- /* TODO: LGA IP*/
- return 0;
+ val = cdns_pcie_readl(pci, CDNS_PCIE_LM_BASE);
+ lga_ltssm = FIELD_GET(CDNS_PCIE_LGA_LTSSM_STATUS_MASK, val);
+ str_ltssm = cdns_pcie_lga_ltssm_status_string(lga_ltssm);
}
- seq_printf(s, "%s (0x%02x)\n", str_ltssm, hpa_ltssm);
+ seq_printf(s, "%s (0x%02x)\n", str_ltssm,
+ pci->is_hpa ? hpa_ltssm : lga_ltssm);
return 0;
}
diff --git a/drivers/pci/controller/cadence/pcie-cadence-ep.c b/drivers/pci/controller/cadence/pcie-cadence-ep.c
index c0e1194a936b..370b19f4d38f 100644
--- a/drivers/pci/controller/cadence/pcie-cadence-ep.c
+++ b/drivers/pci/controller/cadence/pcie-cadence-ep.c
@@ -655,6 +655,7 @@ void cdns_pcie_ep_disable(struct cdns_pcie_ep *ep)
struct device *dev = ep->pcie.dev;
struct pci_epc *epc = to_pci_epc(dev);
+ cdns_pcie_debugfs_deinit(&ep->pcie);
pci_epc_deinit_notify(epc);
pci_epc_mem_free_addr(epc, ep->irq_phys_addr, ep->irq_cpu_addr,
SZ_128K);
@@ -761,6 +762,8 @@ int cdns_pcie_ep_setup(struct cdns_pcie_ep *ep)
pci_epc_init_notify(epc);
+ cdns_pcie_debugfs_init(pcie);
+
return 0;
free_epc_mem:
diff --git a/drivers/pci/controller/cadence/pcie-cadence-host.c b/drivers/pci/controller/cadence/pcie-cadence-host.c
index 0bc9e6e90e0e..8105bb625eb7 100644
--- a/drivers/pci/controller/cadence/pcie-cadence-host.c
+++ b/drivers/pci/controller/cadence/pcie-cadence-host.c
@@ -364,6 +364,7 @@ void cdns_pcie_host_disable(struct cdns_pcie_rc *rc)
{
struct pci_host_bridge *bridge;
+ cdns_pcie_debugfs_deinit(&rc->pcie);
bridge = pci_host_bridge_from_priv(rc);
pci_stop_root_bus(bridge->bus);
pci_remove_root_bus(bridge->bus);
@@ -423,7 +424,13 @@ int cdns_pcie_host_setup(struct cdns_pcie_rc *rc)
if (!bridge->ops)
bridge->ops = &cdns_pcie_host_ops;
- return pci_host_probe(bridge);
+ ret = pci_host_probe(bridge);
+ if (ret)
+ return ret;
+
+ cdns_pcie_debugfs_init(pcie);
+
+ return 0;
}
EXPORT_SYMBOL_GPL(cdns_pcie_host_setup);
diff --git a/drivers/pci/controller/cadence/pcie-cadence.h b/drivers/pci/controller/cadence/pcie-cadence.h
index 2320319af83b..8bc6564c65b9 100644
--- a/drivers/pci/controller/cadence/pcie-cadence.h
+++ b/drivers/pci/controller/cadence/pcie-cadence.h
@@ -14,6 +14,7 @@
#include "pcie-cadence-lga-regs.h"
#include "pcie-cadence-hpa-regs.h"
+#define CDNS_PCIE_LGA_LTSSM_STATUS_MASK GENMASK(29, 24)
#define CDNS_PCIE_HPA_LTSSM_STATUS_MASK GENMASK(27, 20)
enum cdns_pcie_rp_bar {
@@ -44,6 +45,48 @@ enum cdns_pcie_reg_bank {
REG_BANKS_MAX,
};
+enum cdns_pcie_lga_ltssm {
+ CDNS_PCIE_LGA_LTSSM_DETECT_QUIET = 0x00,
+ CDNS_PCIE_LGA_LTSSM_DETECT_ACTIVE = 0x01,
+ CDNS_PCIE_LGA_LTSSM_POLLING_ACTIVE = 0x02,
+ CDNS_PCIE_LGA_LTSSM_POLLING_COMPLIANCE = 0x03,
+ CDNS_PCIE_LGA_LTSSM_POLLING_CONFIGURATION = 0x04,
+ CDNS_PCIE_LGA_LTSSM_CONFIGURATION_LINKWIDTH_START = 0x05,
+ CDNS_PCIE_LGA_LTSSM_CONFIGURATION_LINKWIDTH_ACCEPT = 0x06,
+ CDNS_PCIE_LGA_LTSSM_CONFIGURATION_LANENUM_ACCEPT = 0x07,
+ CDNS_PCIE_LGA_LTSSM_CONFIGURATION_LANENUM_WAIT = 0x08,
+ CDNS_PCIE_LGA_LTSSM_CONFIGURATION_COMPLETE = 0x09,
+ CDNS_PCIE_LGA_LTSSM_CONFIGURATION_IDLE = 0x0A,
+ CDNS_PCIE_LGA_LTSSM_RECOVERY_RCVRLOCK = 0x0B,
+ CDNS_PCIE_LGA_LTSSM_RECOVERY_SPEED = 0x0C,
+ CDNS_PCIE_LGA_LTSSM_RECOVERY_RCVRCFG = 0x0D,
+ CDNS_PCIE_LGA_LTSSM_RECOVERY_IDLE = 0x0E,
+ CDNS_PCIE_LGA_LTSSM_L0 = 0x10,
+ CDNS_PCIE_LGA_LTSSM_RX_L0S_ENTRY = 0x11,
+ CDNS_PCIE_LGA_LTSSM_RX_L0S_IDLE = 0x12,
+ CDNS_PCIE_LGA_LTSSM_RX_L0S_FTS = 0x13,
+ CDNS_PCIE_LGA_LTSSM_TX_L0S_ENTRY = 0x14,
+ CDNS_PCIE_LGA_LTSSM_TX_L0S_IDLE = 0x15,
+ CDNS_PCIE_LGA_LTSSM_TX_L0S_FTS = 0x16,
+ CDNS_PCIE_LGA_LTSSM_L1_ENTRY = 0x17,
+ CDNS_PCIE_LGA_LTSSM_L1_IDLE = 0x18,
+ CDNS_PCIE_LGA_LTSSM_L2_IDLE = 0x19,
+ CDNS_PCIE_LGA_LTSSM_L2_TRANSMITWAKE = 0x1A,
+ CDNS_PCIE_LGA_LTSSM_DISABLED = 0x20,
+ CDNS_PCIE_LGA_LTSSM_LOOPBACK_ENTRY_MASTER = 0x21,
+ CDNS_PCIE_LGA_LTSSM_LOOPBACK_ACTIVE_MASTER = 0x22,
+ CDNS_PCIE_LGA_LTSSM_LOOPBACK_EXIT_MASTER = 0x23,
+ CDNS_PCIE_LGA_LTSSM_LOOPBACK_ENTRY_SLAVE = 0x24,
+ CDNS_PCIE_LGA_LTSSM_LOOPBACK_ACTIVE_SLAVE = 0x25,
+ CDNS_PCIE_LGA_LTSSM_LOOPBACK_EXIT_SLAVE = 0x26,
+ CDNS_PCIE_LGA_LTSSM_HOT_RESET = 0x27,
+ CDNS_PCIE_LGA_LTSSM_RECOVERY_EQUALIZATION_PHASE_0 = 0x28,
+ CDNS_PCIE_LGA_LTSSM_RECOVERY_EQUALIZATION_PHASE_1 = 0x29,
+ CDNS_PCIE_LGA_LTSSM_RECOVERY_EQUALIZATION_PHASE_2 = 0x2A,
+ CDNS_PCIE_LGA_LTSSM_RECOVERY_EQUALIZATION_PHASE_3 = 0x2B,
+ CDNS_PCIE_LGA_LTSSM_UNKNOWN = 0xFFFFFFFF,
+};
+
enum cdns_pcie_hpa_ltssm {
CDNS_PCIE_HPA_LTSSM_DETECT_QUIET = 0,
CDNS_PCIE_HPA_LTSSM_DETECT_QUIET_ENTRY = 1,
--
2.43.0