diff options
Diffstat (limited to 'drivers/pci/controller/dwc/pcie-designware-debugfs.c')
| -rw-r--r-- | drivers/pci/controller/dwc/pcie-designware-debugfs.c | 186 |
1 files changed, 186 insertions, 0 deletions
diff --git a/drivers/pci/controller/dwc/pcie-designware-debugfs.c b/drivers/pci/controller/dwc/pcie-designware-debugfs.c new file mode 100644 index 000000000000..c86befa2fdb0 --- /dev/null +++ b/drivers/pci/controller/dwc/pcie-designware-debugfs.c @@ -0,0 +1,186 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Synopsys DesignWare PCIe controller debugfs driver + * + * Copyright (C) 2025 Samsung Electronics Co., Ltd. + * http://www.samsung.com + * + * Author: Shradha Todi <shradha.t@samsung.com> + */ + +#include <linux/debugfs.h> + +#include "pcie-designware.h" + +#define SD_STATUS_L1LANE_REG 0xb0 +#define PIPE_RXVALID BIT(18) +#define PIPE_DETECT_LANE BIT(17) +#define LANE_SELECT GENMASK(3, 0) + +#define DWC_DEBUGFS_BUF_MAX 128 + +/** + * struct dwc_pcie_rasdes_info - Stores controller common information + * @ras_cap_offset: RAS DES vendor specific extended capability offset + * @reg_event_lock: Mutex used for RAS DES shadow event registers + * + * Any parameter constant to all files of the debugfs hierarchy for a single + * controller will be stored in this struct. It is allocated and assigned to + * controller specific struct dw_pcie during initialization. + */ +struct dwc_pcie_rasdes_info { + u32 ras_cap_offset; + struct mutex reg_event_lock; +}; + +static ssize_t lane_detect_read(struct file *file, char __user *buf, + size_t count, loff_t *ppos) +{ + struct dw_pcie *pci = file->private_data; + struct dwc_pcie_rasdes_info *rinfo = pci->debugfs->rasdes_info; + char debugfs_buf[DWC_DEBUGFS_BUF_MAX]; + ssize_t pos; + u32 val; + + val = dw_pcie_readl_dbi(pci, rinfo->ras_cap_offset + SD_STATUS_L1LANE_REG); + val = FIELD_GET(PIPE_DETECT_LANE, val); + if (val) + pos = scnprintf(debugfs_buf, DWC_DEBUGFS_BUF_MAX, "Lane Detected\n"); + else + pos = scnprintf(debugfs_buf, DWC_DEBUGFS_BUF_MAX, "Lane Undetected\n"); + + return simple_read_from_buffer(buf, count, ppos, debugfs_buf, pos); +} + +static ssize_t lane_detect_write(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + struct dw_pcie *pci = file->private_data; + struct dwc_pcie_rasdes_info *rinfo = pci->debugfs->rasdes_info; + u32 lane, val; + + val = kstrtou32_from_user(buf, count, 0, &lane); + if (val) + return val; + + val = dw_pcie_readl_dbi(pci, rinfo->ras_cap_offset + SD_STATUS_L1LANE_REG); + val &= ~(LANE_SELECT); + val |= FIELD_PREP(LANE_SELECT, lane); + dw_pcie_writel_dbi(pci, rinfo->ras_cap_offset + SD_STATUS_L1LANE_REG, val); + + return count; +} + +static ssize_t rx_valid_read(struct file *file, char __user *buf, + size_t count, loff_t *ppos) +{ + struct dw_pcie *pci = file->private_data; + struct dwc_pcie_rasdes_info *rinfo = pci->debugfs->rasdes_info; + char debugfs_buf[DWC_DEBUGFS_BUF_MAX]; + ssize_t pos; + u32 val; + + val = dw_pcie_readl_dbi(pci, rinfo->ras_cap_offset + SD_STATUS_L1LANE_REG); + val = FIELD_GET(PIPE_RXVALID, val); + if (val) + pos = scnprintf(debugfs_buf, DWC_DEBUGFS_BUF_MAX, "RX Valid\n"); + else + pos = scnprintf(debugfs_buf, DWC_DEBUGFS_BUF_MAX, "RX Invalid\n"); + + return simple_read_from_buffer(buf, count, ppos, debugfs_buf, pos); +} + +static ssize_t rx_valid_write(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + return lane_detect_write(file, buf, count, ppos); +} + +#define dwc_debugfs_create(name) \ +debugfs_create_file(#name, 0644, rasdes_debug, pci, \ + &dbg_ ## name ## _fops) + +#define DWC_DEBUGFS_FOPS(name) \ +static const struct file_operations dbg_ ## name ## _fops = { \ + .open = simple_open, \ + .read = name ## _read, \ + .write = name ## _write \ +} + +DWC_DEBUGFS_FOPS(lane_detect); +DWC_DEBUGFS_FOPS(rx_valid); + +static void dwc_pcie_rasdes_debugfs_deinit(struct dw_pcie *pci) +{ + struct dwc_pcie_rasdes_info *rinfo = pci->debugfs->rasdes_info; + + mutex_destroy(&rinfo->reg_event_lock); +} + +static int dwc_pcie_rasdes_debugfs_init(struct dw_pcie *pci, struct dentry *dir) +{ + struct dentry *rasdes_debug; + struct dwc_pcie_rasdes_info *rasdes_info; + struct device *dev = pci->dev; + int ras_cap; + + /* + * If a given SoC has no RAS DES capability, the following call is + * bound to return an error, breaking some existing platforms. So, + * return 0 here, as this is not necessarily an error. + */ + ras_cap = dw_pcie_find_rasdes_capability(pci); + if (!ras_cap) { + dev_dbg(dev, "no RAS DES capability available\n"); + return 0; + } + + rasdes_info = devm_kzalloc(dev, sizeof(*rasdes_info), GFP_KERNEL); + if (!rasdes_info) + return -ENOMEM; + + /* Create subdirectories for Debug, Error Injection, Statistics. */ + rasdes_debug = debugfs_create_dir("rasdes_debug", dir); + + mutex_init(&rasdes_info->reg_event_lock); + rasdes_info->ras_cap_offset = ras_cap; + pci->debugfs->rasdes_info = rasdes_info; + + /* Create debugfs files for Debug subdirectory. */ + dwc_debugfs_create(lane_detect); + dwc_debugfs_create(rx_valid); + + return 0; +} + +void dwc_pcie_debugfs_deinit(struct dw_pcie *pci) +{ + if (!pci->debugfs) + return; + + dwc_pcie_rasdes_debugfs_deinit(pci); + debugfs_remove_recursive(pci->debugfs->debug_dir); +} + +void dwc_pcie_debugfs_init(struct dw_pcie *pci) +{ + char dirname[DWC_DEBUGFS_BUF_MAX]; + struct device *dev = pci->dev; + struct debugfs_info *debugfs; + struct dentry *dir; + int err; + + /* Create main directory for each platform driver. */ + snprintf(dirname, DWC_DEBUGFS_BUF_MAX, "dwc_pcie_%s", dev_name(dev)); + dir = debugfs_create_dir(dirname, NULL); + debugfs = devm_kzalloc(dev, sizeof(*debugfs), GFP_KERNEL); + if (!debugfs) + return; + + debugfs->debug_dir = dir; + pci->debugfs = debugfs; + err = dwc_pcie_rasdes_debugfs_init(pci, dir); + if (err) + dev_err(dev, "failed to initialize RAS DES debugfs, err=%d\n", + err); +} |